KR101129973B1 - Ceramic Coating Composition for Dissipating Heat and Method for Manufacturing the Same - Google Patents

Abstract

The present invention relates to a heat dissipating ceramic coating composition and a method for manufacturing the same, and specifically, to absorb heat and convert it into infrared rays to dissipate heat so that heat can be generated or the temperature of the absorbing object can be maintained within a certain range. A ceramic coating composition and a method for producing the same. The heat dissipating ceramic coating composition comprises 50 to 70 parts by weight of a cellulose solution prepared by dissolving hydroxy cellulose in alcohol; 80 to 120 parts by weight of colloidal silica diluted with water; 1 to 8 parts by weight of nano inorganic particles; And 80 to 150 parts by weight of the silane compound.

Description

Thermal coating ceramic coating composition and its manufacturing method {Ceramic Coating Composition for Dissipating Heat and Method for Manufacturing the Same}

The present invention relates to a ceramic heat-dissipating coating composition and a method for manufacturing the same, and specifically, by heat-absorbing and converting into infrared radiation to dissipate heat so that the temperature of the object to generate or absorb heat can be maintained in a certain range A ceramic coating composition and a method for producing the same.

Dissipation Heat is an important factor to consider in the product design process of all heat-generating electronic components. Heat dissipation refers to dissipating heat from a portion where the temperature becomes higher than that of the surroundings, and a heat sink, a heat sink, a heat dissipation tape, a heat dissipation pad, or a heat dissipation coating is used as a means for heat dissipation. A heat dissipation coating is applied to a surface of an object that absorbs or generates heat to a certain thickness to quickly dissipate heat to the outside of the object to keep the object in a certain temperature range. The heat dissipation coating may be applied to a portion of the object, for example in the form of a silicone liquid, applied in the form of a paint, or laminated to the surface of the object in the form of a film. All of these heat dissipation methods are characterized in that heat is quickly dissipated to the outside using high thermal conductivity of the material.

Prior art related to a heat dissipation coating is Patent Registration No. 675091 'coating composition for heat dissipation of electronic components'. The prior art relates to a coating composition for heat dissipation of electronic components and discloses a ceramic composition comprising SiO ₂ , Al ₂ O ₃ , SiC, Fe ₂ O ₃ , copper powder, aluminum powder, frit and silver nano binder. . According to the patent, the coating material coated with the ceramic composition dissipates heat in a certain direction in the form of convection, conduction or radiation to lower or maintain the temperature of the coating.

The heat dissipation coating as described above may be installed, for example, with a heater sink to increase the heat dissipation effect, and in some cases, have an advantage of improving physical properties of the workpiece. On the other hand, there is a drawback that the coating film is destroyed by the rapid temperature rise, which may contaminate the surface of the part and the coating process is complicated.

The present invention is to solve the above problems with the prior art has the following object.

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat dissipation coating composition having a high heat dissipation efficiency while being easy to be applied to a workpiece due to a simple coating process.

Another object of the present invention is to provide a method for producing a heat dissipating coating as described above.

According to a preferred embodiment of the present invention, the heat dissipating ceramic coating composition comprises 50 to 70 parts by weight of a cellulose solution prepared by dissolving hydroxy cellulose in alcohol; 80 to 120 parts by weight of colloidal silica diluted with water; 1 to 8 parts by weight of nano inorganic particles; And 80 to 150 parts by weight of the silane compound.

According to another suitable embodiment of the present invention, the hydroxy cellulose is hydroxy propyl cellulose.

According to another suitable embodiment of the present invention, the nano-inorganic particles are silicon carbide (SiC) or beryllium oxide (BeO).

According to another suitable embodiment of the present invention, the method for producing a heat dissipating ceramic coating composition comprises the steps of dissolving hydroxy propyl cellulose in an alcohol solvent to prepare a cellulose solution; Diluting the silica sol with water to produce colloidal silica; Dispersing the nano-inorganic particles while adding colloidal silica to the cellulose solution to prepare a dispersion solution; And adding the silane compound to the dispersion solution.

According to another suitable embodiment of the present invention, the silane is methyltrimethoxy silane.

The heat dissipation coating composition according to the present invention has the advantage that it can be easily prepared by a simple process and can be easily applied to the workpiece in a generally applied method. In addition, the heat-dissipating coating composition according to the present invention has the advantage of excellent heat dissipation characteristics while having excellent stability to temperature with silicon as a main component. In addition, the heat dissipation coating composition according to the present invention can be applied without limitation to the type of the coating and has the advantage of excellent durability of the coating film.

Figure 1 illustrates one embodiment for the manufacturing process of the heat dissipation coating composition according to the present invention.

The present invention will be described in detail below with reference to the presented embodiments, but the embodiments presented are exemplary for clarity of understanding and should not be construed as limiting the scope of the invention.

The heat dissipation coating composition according to the present invention is 50 to 70 parts by weight of a cellulose solution prepared by dissolving hydroxy cellulose in alcohol; 80 to 120 parts by weight of colloidal silica diluted with water; 1 to 8 parts by weight of nano inorganic particles; And 80 to 150 parts by weight of the silane compound.

Hereinafter, a process of preparing such a coating composition will be described in detail.

Figure 1 illustrates one embodiment for the manufacturing process of the heat dissipation coating composition according to the present invention.

Referring to FIG. 1, the process of preparing the coating composition includes preparing a cellulose solution (S11), preparing a colloidal silica (S12), and adding a colloidal silica to the cellulose solution to prepare a mixed solution (S13). ), Dispersing the inorganic particles in the mixed solution to prepare a dispersion solution (S14), adding a silane compound to the dispersion solution (S15) and forming a ceramic coating composition (S16).

Each step will be described in detail below.

I. Preparation of Cellulose Solution

The cellulose solution may be prepared by dissolving hydroxy cellulose which is a thickener in an alcohol solvent. The alcohol can be methanol, ethanol or isopropyl alcohol and the hydroxy cellulose can be such as hydroxyalkylcellulose, methylhydroxyethylcellulose, methylhydroxypropylcellulose or hydroxypropylmethylcellulose, but preferably hydroxypropyl Cellulose. The alcohol solvent may be a mixture of two or more, for example, may be a solvent in which isopropyl alcohol and butanol are mixed. In the case of forming a mixed solvent with two alcohol solvents, at least one solvent may advantageously have a function of preventing gelation of the prepared heat dissipating ceramic coating composition and may be mixed in any ratio. To prepare the hydroxy cellulose solution, 1 to 5 parts by weight of hydroxy cellulose in powder form is slowly dissolved with stirring in 50 to 70 parts by weight of the alcohol solvent. When hydroxy cellulose is completely dissolved, the container of the cellulose solution is kept at room temperature.

II. Preparation of Colloidal Silica

Colloidal silica added to the cellulose solution can be made by diluting the silica sol with distilled water. Refers to silica preserved in sol form with a siloxane group in the form of Si—O—Si or a silanol group in the form of Si—OH. In the silica sol, the silica particles may be, for example, in the size of 1 to 1000 nm and the water mixed with the silica sol may be distilled water. To prepare colloidal silica, 20 to 50 parts by weight of distilled water is slowly added with stirring to 20 to 45 wt% of a solid sol of 50 to 100 silica sol. The addition of water to the silica sol is for dilution and can therefore proceed at any temperature but preferably at room temperature. When the addition of water is complete, the colloidal silica can be maintained at room temperature in a suitable reaction vessel.

III. Preparation of Dispersion Solution

When the cellulose solution and colloidal silica is prepared, a colloidal silica may be added at a predetermined ratio to form a mixed solution (S13), and the dispersion solution may be prepared by dispersing nano-sized inorganic particles. The addition of colloidal silica to the cellulose solution can be made with stirring. The addition rate may be adjusted so that 70 to 150 parts by weight of colloidal silica is maintained with stirring with respect to 51 to 75 parts by weight of the cellulose solution, but the reaction temperature is not particularly limited. The nano-sized inorganic particles may for example be titanium oxide, aluminum hydroxide or titanium oxide but preferably silicon carbide (SiC) or beryllium oxide (BeO). The size of the inorganic particles may be 1 to 500 nm but preferably 5 to 100 nm and may be added in 1 to 8 parts by weight. Inorganic particles can be added with agitation and become a dilute solution when fully dispersed in the mixed solution. If necessary, an ultrasonic disperser may be used to disperse the inorganic particles.

IV. Preparation of Heat Resistant Ceramic Coating Compositions

The silane compound may be added to the dispersion solution to prepare a heat dissipating ceramic coating composition. The silane compound is tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, acryloxypropyltrimethoxysilane, diphenyldimethoxysilane, butyltrimethoxysilane, N-octyltrie Methoxysilane, butyltriethoxysilane, octyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, octyltrimethoxysilane, ditrimethoxysilane, tetra-n-propylsilane, n-propyl Trimethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, triethoxyvinylsilane, vinyltrismethoxyethoxysilane, vinyldimethylcle Lolosilane, diethoxymethylvinylsilane or butyltriethoxysilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, triethylmethoxysilane, ethyltrimethoxysilane or diethyldimethoxysilane This can be Since the exothermic reaction proceeds when the silane compound is added to the dispersion solution, the silane compound may be gradually added while maintaining a temperature of, for example, 40 to 60 ° C with stirring. The silane compound may be added in an amount of 80 to 200 parts by weight based on 122 to 233 parts by weight of the dispersion solution. In general, when a silane compound is added to a silica sol, a chain structure may be formed while hydrolysis and polycondensation are performed, and thus dispersion stability may be weakened according to pH or temperature. Hydroxy cellulose improves dispersion stability while stabilizing the pH of the solution so that the heat dissipation coating composition can be stored in a stable state for a long time.

Heat dissipation ceramic coating composition prepared through the above process may be applied to the coating material is added to other extender pigments or functional additives. Such extender pigments or functional additives may be appropriately selected according to methods known in the art depending on the application to which they are applied and the invention is not limited by the addition of such extender pigments or functional additives. For example, it may be applied to an electronic component requiring heat dissipation to a thickness of about 5 to 50 μm and cured in a natural state to form a heat dissipation coating film.

Hereinafter will be described an embodiment of the coating composition according to the present invention.

Example

Example 1

First step: 20 parts by weight of butanol was mixed with 40 parts by weight of isopropyl alcohol, and 2.6 parts by weight of hydroxypropyl cellulose as a thickener was added in a powder form with stirring to completely dissolve the cellulose solution.

Second step: Colloidal silica was prepared by diluting 70 parts by weight of 30 wt% of the solid sol of silica sol with 30 parts by weight of distilled water. The diameter of the silica sol was 5-20 nm and the dilution was done in such a way that distilled water was added to maintain a temperature of 35-40 ° C.

Step 3: The addition rate was controlled to maintain the temperature of 35 to 40 ℃ while slowly adding colloidal silica to the cellulose solution with stirring. The addition was made in such a way that the first vessel in which the colloidal silica was transferred in an amount by connecting the first vessel containing the cellulose solution to the second vessel containing the colloidal silica through a tube with a check valve. After the colloidal silica was completely added to the first vessel, 3.2 parts by weight of silicon carbide (SiC) was added to prepare a dispersion solution. The particle diameter of the silicon carbide added was prepared to be 5-20 nm and an ultrasonic disperser was used for dispersion.

Step 4: A coating composition was prepared by adding 100 parts by weight of methyltrimethoxysilane (MTS) to the dispersion solution. Since the reaction of adding methyltrimethoxysilane (MTS) to the dispersion solution is exothermic, the reaction was performed for about 1 hour while maintaining a temperature range of 40 to 50.

Example 2

A heat dissipation coating composition was prepared in the same manner as in Example 1 except that the solid content of the silica sol was 35 wt% in the second step.

Example 3

Except that 100 parts by weight of methyltriethoxy silane was used in Step 4 to prepare a heat-dissipating ceramic coating composition through the same process as in Example 1.

Example 4

Except for using 120 parts by weight of isobutyl trimethoxy silane in step 4 to prepare a heat-dissipating ceramic coating composition through the same process as in Example 1.

Example 5

Except that 5 parts by weight of methyl hydroxyethyl cellulose was used in Step 1 to prepare a heat-dissipating ceramic coating composition through the same process as in Example 1.

Example 6

A heat-dissipating ceramic coating composition was prepared through the same process as in Example 1, except that 3 parts by weight of aluminum hydroxide of 5 to 20 nm was added in step 3.

Example 7

A heat-dissipating ceramic coating composition was prepared in the same manner as in Example 1, except that 3 parts by weight of titanium oxide of 5 to 20 nm was added in step 3.

Example 8

A heat-dissipating ceramic coating composition was prepared in the same manner as in Example 1, except that 3 parts by weight of 5 to 20 nm beryllium oxide was added in Step 3.

Example 9

A heat dissipating ceramic coating composition was prepared through the same process as in Example 1, except that 1.5 parts by weight of silicon carbide and 1.5 parts by weight of beryllium oxide were added.

Example 10

A heat-dissipating ceramic coating composition was prepared in the same manner as in Example 1, except that 1.0 part by weight of silicon carbide, 1.0 part by weight of aluminum hydroxide, and 1.0 part by weight of beryllium oxide were added.

Example 11

Heat dissipating ceramic coating composition was removed through the same process as in Example 1 except that 50 parts by weight of methyltrimethoxy silane and 50 parts by weight of isobutylmethoxy silane were reacted in step 4.

In order to evaluate the properties of the ceramic heat-dissipating coating composition, the composition prepared in each example was applied to an aluminum specimen of 50 × 50 × 5 mm to a thickness of 10 to 30 μm, and cured for 40 to 45 minutes by applying heat. It was left at room temperature for days (samples). For comparison, the same volume of aluminum specimens were prepared (comparative) and the temperature was measured by applying the same heat to the two specimens.

Heat dissipation contrast time One 2 3 4 5 6 7 8 9 10 Comparison 40 53 66 78 90 101 111 120 127 135 EX1 29 41 53 64 75 85 94 100 105 108 EX2 29 41 54 65 76 86 95 101 106 109 EX3 29 41 53 64 75 86 95 101 106 109 EX4 28 40 52 63 74 84 94 100 105 109 EX5 29 41 53 64 75 85 94 100 105 108 EX6 29 41 53 65 76 86 96 102 107 111 EX7 29 41 53 64 75 85 94 100 104 106 EX8 28 40 52 63 74 84 93 98 102 105 EX9 28 40 52 63 74 84 93 98 102 105 EX10 27 39 51 62 73 82 91 95 98 100 EX11 29 41 53 64 75 85 94 100 105 108

※ Time is expressed in minutes, and the temperature change over time was measured in ℃ by applying a certain amount of heat in a closed space.

As shown in Table 1, it can be seen that as the temperature increases, the temperature difference increases. In addition, it can be seen that the heat dissipation effect is slightly different depending on the type of nano-inorganic particles.

The thermal conductivity of the heat dissipating ceramic coating composition prepared according to each embodiment was 1.0 to 1.8 Watt / mK, and the heat dissipation effect of at least 15% when applied to 20 × 40 × 40 mm aluminum heating element or stainless steel heating element with a thickness of 20 μm. Appeared to increase. The heat dissipation effect appears to be caused by the absorbed heat being converted into electromagnetic waves such as infrared radiation and released. To verify this, radiant heat was measured using a thermal camera on the same specimen and the results are presented in Table 2.

Radiation heat measurement result time One 2 3 4 5 6 7 8 9 10 Comparison 100 101.1 107.5 115.6 123.7 132.6 132.9 133.4 133.5 134.2 EX1 108.6 200.8 411.8 520.3 600.7 630.6 640.0 650.2 660.3 680.2 EX2 108.6 199.7 411.5 520.0 599.3 630.0 639.1 648.3 657.2 670.0 EX3 107.9 200.9 411.9 520.4 600.8 630.9 641.1 650.2 660.1 680.3 EX4 110.1 203.9 415.3 525.1 600.6 635.6 640.1 649.5 660.3 679.1 EX5 108.2 201.4 411.9 519.9 600.2 630.1 640.0 651.0 662.3 684.2 EX6 108.2 200.5 411.2 520.1 599.8 625.6 630.1 640.1 650.2 660.8 EX7 108.1 200.3 412.1 519.8 597.3 620.3 625.3 630.7 640.3 652.4 EX8 110.3 201.2 413.1 520.3 601.4 629.7 640.3 650.0 659.9 680.3 EX9 109.7 204.7 416.9 525.4 607.2 635.7 650.1 660.7 678.1 699.1 EX10 111.2 210.4 420.7 530.2 620.3 650.1 672.1 690.3 700.2 724.3 EX11 108.2 200.2 410.9 521.2 602.1 629.7 641.1 650.1 663.0 679.3

* The time was measured in minutes and the radiant heat was measured relative to the measured value of 100 after one minute had elapsed by applying heat to the comparative specimen and measured at a distance of about 10 cm from the surface of the specimen.

As shown in Table 2, it can be seen that the specimens applied by the coating composition according to the invention significantly increase radiant heat. Therefore, it can be seen that the heat dissipation ceramic coating composition according to the present invention may exhibit heat dissipation effect by absorbing heat and converting it into electromagnetic waves and releasing them to the outside.

The coating composition according to the invention can be applied to all electronic components and applied to any electronic components that require heat dissipation, such as heat dissipation of LEDs for lighting, heat dissipation of microprocessors, heat dissipation of graphics cards or heat dissipation of displays, for example 15%. The heat dissipation effect can be improved above. In addition, it has the advantage that it can be applied to any cooking wall, sauna equipment or heating wall is required. In addition, the coating composition according to the present invention may be applied to the surface of a heat dissipation device, such as a heat sink, for example, and may be applied to improve the efficiency of the heat dissipation device.

The heat dissipating ceramic coating composition according to the present invention has the advantage that it can be easily prepared in a simple process and can be easily applied to the coating in a generally applied method. In addition, the heat dissipation coating composition according to the present invention has an advantage of excellent heat dissipation characteristics while at the same time excellent in stability to temperature. In addition, the heat dissipation coating composition according to the present invention can be applied without limitation to the type of the coating and has the advantage that the coating is excellent in durability.

S11: Preparation of Cellulose Solution
S12: Preparation of Colloidal Silica
S13: mixed
S14: Addition of Inorganic Particles
S15: Addition of silane compound
S16: heat dissipating ceramic coating composition

Claims (5)

50 to 70 parts by weight of a cellulose solution prepared by dissolving hydroxy cellulose in alcohol;
80 to 120 parts by weight of colloidal silica diluted with water;
1 to 8 parts by weight of nano inorganic particles; And
A heat dissipating ceramic coating composition comprising 80 to 150 parts by weight of silane compound. The heat dissipating ceramic coating composition of claim 1, wherein the hydroxy cellulose is hydroxy propyl cellulose. The heat dissipating ceramic coating composition according to claim 1, wherein the nano inorganic particles are silicon carbide (SiC) or beryllium oxide (BeO). Preparing a cellulose solution by dissolving hydroxy propyl cellulose in an alcohol solvent;
Diluting the silica sol with water to produce colloidal silica;
Preparing a dispersion solution by adding nano inorganic particles while adding colloidal silica to a cellulose solution; And
A method of producing a heat dissipating ceramic coating composition comprising adding a silane compound to a dispersion solution. The method of claim 4, wherein the silane compound is methyltrimethoxy silane.

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