KR20090062456A - Dielectric ceramics for ion producing cluster and manufacturing method thereof - Google Patents

Abstract

Dielectric ceramics for ion generation cluster are provided to enable sintering in an ION GENERATION apparatus, to remove operation voltage, and to reduce electrical energy consumption. A method for manufacturing dielectric ceramics comprises the steps of: mixing and pulverizing MgO and SiO2 samples according to mole fraction of chemical formula: xMgO-SiO2 (at this time, 1<=x<=2 mole), and then calcining the pulverized material to prepare Mg2SiO4 powder; mixing and pulverizing B2O3, ZnO, Na2O, SiO2, Al2O3 samples according to mole fraction of chemical formula: cB2O3-dZnO-eNa2O-fSiO2-gAl2O3 (at this time, 30wt%<=c<=50wt%, 25wt%<=d<=32wt%, 10wt%<=e<=20wt%, 5wt%<=f<=15wt%, 0<=g<=5) to prepare glass frit; adding glass frit to the Mg2SiO4 powder in the amount of 10-30 vol%, and then mixing and pulverizing the mixture to prepare green sheet; and forming electrode patterns on the green sheet and sintering the product.

Description

Dielectric ceramics for ion generating cluster and manufacturing method thereof {DIELECTRIC CERAMICS FOR ION PRODUCING CLUSTER AND MANUFACTURING METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to dielectric ceramics for ion generating clusters and methods of manufacturing the same, and more particularly, to dielectric ceramics for ion generating clusters capable of low temperature sintering and air atmosphere sintering that can be produced by ion generating clusters of ion generating devices.

In general, the ion generating device is provided in an enclosed room and discharges the ion cluster into the room or is integrally provided with an air purifier and the like to contain the ion cluster in the air discharged therefrom.

That is, conventional ion generating apparatus emitting positive ions and negative ions in the air, and wherein a plurality of water molecules, the hydrogen ion (H ⁺⁾ or oxygen ions (O _{2 -)} is attached around the cations are H ⁺ (H ₂ O) _In the form of _m , the anion becomes a so-called ion cluster in the form of O _{2 −} (H ₂ O) _n . These ion clusters are bonded around the particles suspended in the air, causing chemical reactions to form hydrogen peroxides (H ₂ O ₂ ) or hydroxyl radicals (OH) as active species, and perform oxidation reactions to remove hydrogen from the suspended particles. Inactivates suspended particles to sterilize suspended fungi, viruses and bacteria.

The ion generating device mainly uses a DC high voltage method, and in particular, the corona discharge method anionizes an air molecule such as oxygen between the two electrodes by generating a corona discharge by applying a high voltage between the discharge electrode and the ground electrode, which are ion generating electrodes. Release into the air. Prior arts related to this are disclosed in Japanese Patent Application Laid-Open No. Hei 4-90428 (published on March 24, 1992), Japanese Patent Application Laid-open No. Hei 8-217412 (released on August 27, 1996), and Japanese Patent Publication No. Hei 3-230499 (1991). 10. 14 publication), Japanese Patent Laid-Open No. 9-610 (published on Jan. 7, 1997) and the like.

As described above, ion generating electrodes using the discharge phenomenon are generally classified into two types.

One of them has a structure including an electrode made of a metal plate, a needle, or the like having a wire or an acute portion, and an opposite electrode made of a metal plate or a grid having an earth or earth potential. However, in this case, since the air between the two electrodes functions as an insulator, it is necessary to design a wide distance between the two electrodes, and accordingly, there is a problem that the voltage required for discharge becomes high.

 The other has a structure in which a discharge electrode and an induction electrode are formed with a solid dielectric ceramic interposed therebetween. In this case, since a dielectric having high insulation resistance and high dielectric constant is inserted between the two electrodes, it is possible to design a short distance between the electrodes, thereby lowering the applied voltage for discharging.

In particular, in the conventional ion generating apparatus using the latter dielectric ceramic, the ion generating electrode includes a discharge electrode disposed outside of the dielectric ceramic and an induction electrode disposed inside thereof, and an AC impulse voltage is applied to these electrodes. ~ 3.0kV is applied to generate ions. However, the electrodes used in the ion generating electrode are made of tungsten material, and the manufacturing process is difficult and manufacturing cost is increased due to the high sintering temperature and reducing atmosphere conditions of 1550 ° C. or more when the dielectric ceramic is manufactured. Moreover, since the applied voltage is a high voltage, there is also a problem that shortens the lifetime of the dielectric ceramic and increases the power consumption.

Accordingly, the present invention has been made to solve the above problems, the object of the present invention is the ion generating cluster which can be sintered at low temperature and air atmosphere in the ion generating device and the operating voltage is lowered to reduce the power consumption The present invention provides a dielectric ceramics and a method of manufacturing the same.

In order to achieve the above object, the dielectric ceramic composition according to one aspect of the present invention may have a composition formula xMgO-SiO ₂ + αvol% (cB ₂ O ₃ -dZnO-eNa ₂ O-fSiO ₂ -gAl ₂ O ₃ ), wherein 1 ≦ x≤2 mol, 30wt% ≤c≤50wt%, 25wt% ≤d≤32wt%, 10wt% ≤e≤20wt%, 5wt% ≤f≤15wt%, 0≤g≤5, 10≤α≤30 Has

In addition, according to another aspect of the present invention, there is provided a method for preparing a dielectric ceramic composition comprising MgO and SiO ₂ samples in a composition formula xMgO-SiO _2. At this time, it is mixed and pulverized according to the mole fraction of 1 ≦ x ≦ 2 mol) and calcined to Mg ₂ SiO ₄ A powder is prepared, and the B ₂ O ₃ , ZnO, Na ₂ O, SiO ₂ , and Al ₂ O ₃ samples are prepared using the formula cB ₂ O ₃ -dZnO-eNa ₂ O-fSiO ₂ -gAl ₂ O ₃ (At this time, 30wt% ≤c≤50wt%, 25wt% ≤d≤32wt%, 10wt% ≤e≤20wt%, 5wt% ≤f≤15wt%, 0≤g≤5) by mixing and grinding the glass Preparing a frit, and forming the glass frit into the Mg ₂ SiO ₄ 10 to 30 vol% of the powder may be mixed and pulverized to prepare a green sheet thereof, and an electrode pattern may be formed on the green sheet and pressurized to sinter it. At this time, the sintering temperature is 1000 ℃ to 1100 ℃, the electrode may be made of Ag-Pd material.

As described above, according to the present invention, the ion generating cluster composition in the ion generating device is prepared by adding glass frit to the forsterite crystalline composition, thereby reducing the low temperature sintering and air atmosphere sintering. It is possible to greatly reduce the manufacturing process and manufacturing cost, and also greatly reduce the power consumption, which is very promising.

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

The present invention can be applied to any of the ion generating devices known in the art, in particular, preferably applied to the ion generator of the corona discharge method. Figure 1 shows a schematic structural diagram of the corona discharge type ion generating device according to a preferred embodiment of the present invention.

First, the ion generator 1 according to the preferred embodiment of the present invention is formed on the induction electrode 8 formed on the substrate 3 and the insulating layer 2 made of a dielectric ceramic. And a discharge electrode 7 facing each other. In addition, a protective layer 4 made of a dielectric ceramic is formed on the discharge electrode 7 to protect the discharge electrode 7.

The substrate 3 may be any ceramic sintered body having a generally high insulating property known in the art, and may be, for example, alumina, silicon, or the like.

In addition, the insulating layer 2 may have a composition in which glass frit is added to the forsterite crystalline composition. Its composition is given by Equation 1 below:

 xMgO-SiO₂ + Alpha vol% (cB₂O₃-dZnO-eNa₂O-fSiO₂-gAl₂O₃) (Equation 1)

At this time, 1≤x≤2mol, 30wt% ≤c≤50wt%, 25wt% ≤d≤32wt%, 10wt% ≤e≤20wt%, 5wt% ≤f≤15wt%, 0≤g≤5, 10 ≤ α ≤ 30.

The glass frit composition of the added B ₂ O ₃ —ZnO—Na ₂ O—SiO ₂ —Al ₂ O ₃ system has a glass transition temperature (Tg) of about 460 ° C. Thus, by the addition of the glass frit having such a low glass transition temperature in the system MgO-SiO ₂ it is a glass transition temperature of the system MgO-SiO ₂ significantly decreased, and thus it is possible to low-temperature co-fired in the range of 1000 ~ 1100 ℃.

Accordingly, in one embodiment of the present invention, the material of the induction electrode 8 and the discharge electrode 7, which was possible only through conventional high temperature firing, is replaced with Ag-Pd material capable of low temperature firing. Low temperature simultaneous firing with the insulating layer 2 becomes possible.

In addition, in another embodiment of the present invention, the substrate 3, the insulating layer 2 and the protective layer 4 can all be made of the composition according to the formula (1).

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. However, the embodiments described below are provided to help the overall understanding of the present invention, and the present invention is not limited only to the following examples.

Example  1-21

In the present embodiments, the ion generating electrode was manufactured according to Equation 1, in which the glass frit was added to the phosphite crystal crystalline composition, and various characteristics were measured and compared.

First, MgO and SiO ₂ with a purity of 99.9% or more were weighed at a composition ratio according to Equation 1, and mixed and ground in a polyethylene container. The mixed powder was dried at 100 ° C. for 24 hours, and then calcined at 1300 ° C. for 2 hours to prepare Mg ₂ SiO ₄ .

In addition, B ₂ O ₃ , ZnO, Na ₂ O, SiO ₂ , Al ₂ O ₃ were weighed in a composition ratio according to the formula 1 and mixed in a polyethylene container using a reagent having a purity of 99.9% or more. Shown in The mixed powder was put into a platinum crucible and held at 1300 ° C. for 1 hour to be melted, and then poured between metal rollers to form a ribbon cullet in the form of a thin sheet and pulverized it. The glass thus prepared was first pulverized through a disk mill, and then ball milled with ethanol for 24 hours using a zirconia ball in an alumina container to prepare a final glass frit.

In addition, the prepared glass frit was added to Mg ₂ SiO ₄ in a composition ratio of 10, 20, and 30 vol%, respectively, and the mixture was wet mixed with ethanol for 24 hours and then dried. In this case, as the binder, plasticizer, and dispersant used, a slurry was prepared using PVB, DBP, and SN, respectively. The solvent used was a mixed solution of toluene and ethanol under azeotropic conditions. The glass powder or ceramic powder, a dispersant, and a solvent were added and dispersed firstly for 24 hours using zirconia balls. The dispersed slurry was secondary milled for 24 hours with a binder and a plasticizer to prepare a final slurry. The slurry thus prepared was prepared using a doctor blade to prepare a uniform green sheet having a thickness of about 95 to 100 μm. In addition, a pattern was formed on the green sheet using an Ag-Pd electrode. Then, the green sheets were sequentially laminated and subjected to isostatic molding at 250 bar, and then cut to a constant size. In addition, the prepared sheet was debindered by maintaining the temperature for 1 hour after heating up to 600 ℃ to remove the organic matter present in the laminate. The sample from which the organic substance was removed was sintered at 1000-1100 degreeC in air for 1 hour.

Each composition of the above-described embodiments are summarized as shown in Table 1 below, and particularly show the corresponding density and dielectric constant when sintered at 1050 ° C.

Example Forsterite (vol%) Content (wt%) of each component in B ₂ O ₃ -ZnO-Na ₂ O-SiO ₂ -Al ₂ O ₃ system Density (g / cm ³ ) permittivity B ₂ O ₃ ZnO Na ₂ O SiO ₂ Al ₂ O ₃ One 90 50 30 10 10 0 3.02 6.5 2 90 50 35 10 4 One 3.06 6.5 3 90 50 40 5 5 One 3.11 6.8 4 90 55 30 12 3 0 3.10 6.8 5 90 55 34 5 5 One 3.12 6.8 6 90 55 35 6 3 One 3.07 6.6 7 90 55 35 5 5 One 3.09 6.7 8 90 60 30 5 4 One 3.11 6.7 9 90 60 30 6 4 0 3.08 6.5 10 90 60 40 5 5 0 3.06 6.6 11 80 50 30 10 10 0 3.04 6.2 12 80 50 30 15 4 One 3.07 6.3 13 80 50 35 10 4 One 3.04 6.3 14 80 50 40 5 5 0 2.98 6.2 15 80 55 30 12 3 0 2.90 6.1 16 80 55 34 5 5 One 2.95 6.1 17 70 55 35 6 3 One 2.96 6.1 18 70 55 35 5 5 One 2.92 6.2 19 70 60 30 5 4 One 2.96 6.0 20 70 60 30 6 4 0 2.92 5.9 21 70 60 40 5 5 0 2.92 6.0

In addition, anion generation characteristics of the ion generating clusters prepared by the composition of Example 5 in the above examples were measured. This is done by connecting the sintered cluster specimens to an applied power source and measuring the amount of negative ions generated for 1 hour using the air suction method when the distance between the sample and the negative ion meter to be measured using an ion meter (FIC2000, Fisa, Japan) is 1 cm. Was performed. In particular, referring to FIG. 1, the thickness of the protective layer 7 formed on the discharge electrode 7 (indicated by “a”), the induction electrode 8 and the discharge electrode formed in the insulating layer 2 ( 7) The amount of ions generated was measured while varying the distance (indicated by "b"). The results thereof are shown in FIGS. 2 and 3, respectively.

In addition, Figure 4a, Example 5, Figure 4b is Example 16, Figure 4c shows an electron micrograph of the ion generating clusters prepared by the compositions of Example 18. 5 shows the breakdown voltage characteristics when the sintering temperature of Example 5 is changed from 1050 ° C. to 1150 ° C., and FIG. 6 is 3 when the sintering temperature of Example 5 is changed from 1050 ° C. to 1150 ° C. Medium bending strength characteristics.

In particular, referring to Figures 2 and 3, it can be seen that the best properties come out until the distance (b) between the induction electrode 8 and the discharge electrode 7 is approximately 750㎛ at an applied voltage 1.0kV, particularly preferred It is 300-500 micrometers below. In the conventional case, the applied voltage reached a maximum of 3.0 kV, but according to the present invention, it is 1.0 kV, which is much lower than the conventional one, thereby reducing power consumption.

Therefore, when the ion generating cluster is manufactured by the composition according to the present invention, low temperature sintering and sintering of the air atmosphere are possible, and thus the manufacturing process and manufacturing cost can be reduced, and power consumption is greatly reduced.

Meanwhile, in the above-described embodiments of the present invention, the powder characteristics such as the average particle size, distribution, and specific surface area of the sample powder, the purity of the raw material, the amount of impurity added, and the sintering and atmosphere conditions vary slightly within the usual error range. It can be quite natural for one with ordinary knowledge in the field.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, anyone of ordinary skill in the art will be possible to various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications, changes And additions should be regarded as within the scope of the claims.

1 is a schematic structural diagram of the corona discharge ion generating device according to a preferred embodiment of the present invention.

2 is a graph showing ion generation characteristics according to a change in a thickness (denoted by "a") of a protective layer formed on a discharge electrode in embodiments of the present invention.

3 is a graph showing ion generation characteristics according to a change in the distance between the induction electrode and the discharge electrode (indicated by "b") formed in the insulating layer in the embodiments of the present invention.

4A to 4C are electron micrographs in the embodiments of the present invention, and FIG. 4A is an ion generating cluster prepared by the compositions of Example 5, FIG. 4B is Example 16, and FIG. 4C is Example 18, respectively. Electron micrograph of a child.

5 is a graph showing the breakdown voltage characteristics when the sintering temperature of the fifth embodiment of the present invention is changed from 1050 ° C to 1150 ° C.

6 is a graph showing the triple bending strength characteristics when the sintering temperature of Example 5 of the present invention is changed from 1050 ° C to 1150 ° C.

Claims (5)

A dielectric ceramic composition comprising a composition represented by the following compositional formula. xMgO-SiO ₂ + αvol% (cB ₂ O ₃ -dZnO-eNa ₂ O-fSiO ₂ -gAl ₂ O ₃ ) At this time, 1≤x≤2mol, 30wt% ≤c≤50wt%, 25wt% ≤d≤32wt%, 10wt% ≤e≤20wt%, 5wt% ≤f≤15wt%, 0≤g≤5, 10 ≤ α ≤ 30. MgO and SiO ₂ samples were formulated as xMgO-SiO ₂ At this time, it is mixed and pulverized according to the mole fraction of 1 ≦ x ≦ 2 mol) and calcined to Mg ₂ SiO ₄ Preparing a powder; B ₂ O ₃ , ZnO, Na ₂ O, SiO ₂ , Al ₂ O ₃ Samples were formulated cB ₂ O ₃ -dZnO-eNa ₂ O-fSiO ₂ -gAl ₂ O ₃ (At this time, 30wt% ≤c≤50wt%, 25wt% ≤d≤32wt%, 10wt% ≤e≤20wt%, 5wt% ≤f≤15wt%, 0≤g≤5) by mixing and grinding the glass Preparing a frit; The glass frit is the Mg ₂ SiO ₄ Adding 10 to 30 vol% to the powder to mix and grind and prepare a green sheet thereof; Forming an electrode pattern on the green sheet and pressing the sintering method for producing a dielectric ceramic composition, characterized in that consisting of. The method of claim 2, The sintering temperature is a method for producing a dielectric ceramic composition, characterized in that 1000 ℃ to 1100 ℃. The method according to claim 2 or 3, The electrode is a method of producing a dielectric ceramic composition, characterized in that the Ag-Pd material. An ion generating device comprising an ion generating cluster made of the dielectric ceramic composition according to claim 1.

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