KR20160093928A - Elastic coating composition with heat conductive and spread function - Google Patents

Abstract

The present invention relates to an elastic paint composition with radiant function. More specifically, the present invention relates to an elastic paint composition which includes: thermoplastic elastomer as a binding resin; a hydrocarbon-based organic solvent dissolving the elastomer so as to make the same into liquid paint; and a functional filler offering the composition with radiant function, thereby forming radiant coating films which effectively conduct and emit heat from a conductor, while exhibiting inherent dampproofing and anticorrosive effects of liquid elastic paint.

Description

TECHNICAL FIELD [0001] The present invention relates to an elastic coating composition,

More particularly, the present invention relates to a thermoplastic elastomer composition comprising a thermoplastic elastomer as a binding resin, a hydrocarbon-based organic solvent which dissolves the elastomer into a liquid coating material, and a functional filler (Filler), which is an object of the present invention to provide an elastic coating composition which forms a heat-dissipating coating that effectively transmits and discharges heat of a conductor, as well as a moisture-proofing and corrosion effect inherent to the liquid-elastic coating.

Conventionally, a liquid coating composition made of a synthetic resin material has been developed which forms a protective coating on the surface of an object to protect an object, that is, a coated object from external impact, moisture, corrosion, or contamination.

For example, the peelable coating composition disclosed in Korean Patent Publication No. 2006-84237 (published on July 24, 2006) comprises 0.1 to 100 parts by weight of a talc filler per 100 parts by weight of the thermoplastic rubber; 0.1 to 50 parts by weight of a primary release agent selected from stearic acid, vegetable oil and process oil; 0.1 to 50 parts by weight of a secondary release agent selected from stearic acid to which zinc (Zn) is added, vegetable oil and process oil; 0.1 to 50 parts by weight of a toner pigment; 0.1 to 200 parts by weight of a primary solvent which is a hydrocarbon-based organic solvent; And 0.1 to 500 parts by weight of a secondary solvent which is a hydrocarbon-based organic solvent; And a control unit.

The releasable coating composition is advantageous in that it is easy to apply as a liquid phase irrespective of the shape and structure of the conductor, and particularly, when a release agent is contained, it is easily peeled off when the film is to be peeled off. The coatings formed by these conventional coating compositions generally have properties that block conduction or emission of heat.

In recent years, along with the development of the electronic industry, various electronic products, particularly semiconductor components and display components, have become increasingly highly integrated and miniaturized, and it is necessary to efficiently solve heat problems generated in LCDs, PDPs, Is a very important factor affecting the performance and life span of the product. Therefore, a heat sink or a heat sink is installed in these electronic products to quickly cool the heat generated by the heat source. A heat transfer material such as a thermal grease, a heat dissipation pad, or a heat dissipation tape, that is, TIM (Thermal Interface Materials) is inserted between the heat source and the heat sink.

However, the conventional TIM has a function of simply transferring the heat generated from the heat source to the heat sink, and does not perform the function of discharging the heat accumulated in the heat sink to the air. Especially recently, aluminum, which is mainly used as a material of heat sink or heat sink, is excellent in thermal conductivity, but it has a heat retaining property to catch heat, so that if the heat of the heat sink is not released quickly into the air, Can not.

Moreover, if a conventional liquid coating material is coated on the surface of the electronic device in order to protect the heat source, the heat sink, and the heat dissipation plate of the electronic product, the coating prevents heat emission from the object, .

It is an object of the present invention to solve the problems of the prior art described above, and it is an object of the present invention to provide a protective film which is easy to apply without any structure or form of the conductor, There is provided an elastic coating composition having a heat dissipating function that effectively causes the coating to conduct and discharge heat of the conductor.

In order to attain the above object, the elastic coating composition having a heat radiation function of the present invention is characterized by comprising 50 to 500 parts by weight of a hydrocarbon-based organic solvent, 100 to 500 parts by weight of a thermally conductive filler, And 10 to 200 parts by weight of a heat-releasing filler.

The elastic coating composition of the present invention is a liquid coating composition which is easy to apply regardless of the structure and form of the conductor to be coated and forms a film having excellent heat dissipation characteristics and elasticity after drying and furthermore, Or an insulating film may be formed.

Therefore, the elastic coating composition according to the present invention can be used not only in general metal products, electric and electronic products for forming moisture-proof and protective coatings, but also in the case of rapidly releasing heat generated from a conductor to air, EMI, EMS) for forming an antistatic film, or when an adhesive force and a thermal conductivity between two objects are simultaneously required, heat radiation property and insulation property are required at the same time.

Hereinafter, the present invention will be described in detail.

The elastic coating composition having a heat radiation function according to the present invention comprises 50 to 500 parts by weight of a hydrocarbon-based organic solvent and 10 to 200 parts by weight of a heat dissipating filler per 100 parts by weight of the olefin-based or styrene-based thermoplastic elastomer.

First, the thermoplastic elastomer is a binder resin, which is solid at room temperature, but is dissolved in a hydrocarbon-based organic solvent as a solvent to form a liquid coating. After coating and drying on the coated body, the organic solvent is volatilized to a predetermined thickness Is formed.

Examples of the thermoplastic elastomer include EPDM (Ethylene Propylene Diene Monomer), EPM (Ethylene Propylene Monomer), EPD (Ethylene Propylene Dicyclo pentadiene), EPR (Ethylene Propylene Rubber), NBR (Nitrile Butadiene Rubber), SBR Rubber, SBS (Styrene Butadiene Styrene), SES (Styrene Ethylene Styrene), SIS (Styrene Isoprene Styrene), SEPS (Styrene Ethylene Butylene Styrene) rubber and SEBS .

Next, the hydrocarbon-based organic solvent functions to dissolve the thermoplastic elastomer into a liquid phase. Since the volatile organic solvent easily volatilizes in the air, it is quickly dried after being coated on the coated body, so that the binder resin forms a solid coating.

As the organic solvent, any one or more selected from toluene, n-hexane, cyclohexane, pentane, xylene, isooctane and heptane may be used, and the content thereof is 50 to 500 parts by weight based on 100 parts by weight of the thermoplastic elastomer . If the content of the organic solvent is 50 parts by weight or less, the viscosity of the elastic coating composition becomes too high, and the coating operation becomes difficult. On the other hand, if the content of the organic solvent is 500 parts by weight or more, the thickness of the coating film becomes too thin, And the drying time is further delayed. The content of the organic solvent varies greatly depending on the type of heat-resisting filler described below.

Finally, a heat-radiating filler is a component that provides a heat-radiating function, which is a feature of the present invention, and includes aluminum oxide (Al ₂ O ₃ ), boron nitride (BN), silicon carbide (SiC), silicon nitride, beryllium oxide Or one or more selected from aluminum nitride (AlN), carbon nanotubes (CNT), graphite, copper (Cu), and silver (Ag). It is preferable that the heat-radiating filler has a size of 10 μm or less, preferably 0.1 to 5 μm.

The heat-radiating filler can be classified into an insulating filler and a conductive filler according to electrical characteristics. That is, aluminum oxide (Al ₂ O ₃ ), boron nitride (BN), silicon carbide (SiC), silicon nitride, beryllium oxide (BeO) and aluminum nitride (AlN) belong to insulative fillers and include carbon nanotubes Graphite, copper (Cu) and silver (Ag) belong to the conductive filler.

In the present invention, if necessary, the insulating filler and the conductive filler may be separated from each other, and one or more of them may be selected and used to produce the insulating heat radiation coating material, or to produce the conductive heat radiation coating material.

The content of the heat-radiating filler is 10 to 200 parts by weight based on 100 parts by weight of the thermoplastic elastomer. If the amount of the heat-radiating filler is less than 10 parts by weight, heat dissipation is hardly expected. On the other hand, if the amount of the filler is more than 200 parts by weight, the filler may not be uniformly dispersed in the binder, I can not expect it.

The elastic coating composition according to the present invention may contain 0.5 to 5 parts by weight of a UV stabilizer and a UV blocking agent in order to enhance ultraviolet (UV) characteristics in addition to the above three essential constituents, And 2 to 20 parts by weight of a pigment.

In addition, Talc may be included as a lubricant to improve the fluidity of the liquid coating material and to improve the texture of the coating film. In this case, since talc has a high specific gravity and is easily precipitated, there is an inconvenience that it must be used after sufficiently stirring each time it is used.

The elastic coating composition according to the present invention preferably maintains its viscosity at 100 to 5,000 cps according to the kind of the conductor and the working method. The viscosity is adjusted according to the content of the organic solvent.

The heat radiation characteristics of the elastic coating composition are such that the heat radiation characteristics are generally increased as the thickness of the coating is thicker within the range of 20 to 300 mu m. However, if the thickness of the film is 300 탆 or more, the heat radiation effect does not increase any more even if the thickness of the film increases, or rather adversely affects.

In the method for producing an elastic coating composition according to the present invention, a 'liquid binder' in which the binder resin is dissolved in the hydrocarbon-based organic solvent and a 'filler mixture' in which the heat dissipative filler is uniformly dispersed in the organic solvent are separately prepared, It is preferable to mix the liquid binder and the filler mixture again to prepare the final object.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following embodiments are not intended to limit the scope of the present invention.

[Example 1]

First, 800 g of SBS was sufficiently dissolved in a mixed solvent of 600 g of toluene and 600 g of xylene to prepare a liquid binder. Further, 150 g of Al ₂ O ₃ having a particle diameter of 1 to 2 μm, 100 g of BN and 100 g of SiC were mixed in 600 g of toluene, The mixture was thoroughly stirred with a milling machine and a high-speed stirrer for about 1 hour to prepare a filler mixture.

Then, the liquid binder and the filler mixture were mixed again and stirred sufficiently for about 2 to 3 hours to obtain an elastic coating composition of the present invention. At this time, since toluene solvent continuously volatilized during the stirring process, the amount of toluene solvent was replenished in the middle as the initial amount.

The SBS elastic coating composition prepared according to Example 1 had a specific gravity of 0.94, a hardness of the surface of the coating after drying was 90 by Shore A hardness, and elongation was 300 to 800% depending on the thickness of the coating.

[Examples 2 to 9]

The elastic coating composition of the present invention was prepared by changing the kind and content of the binder resin, the organic solvent, and the heat dissipative filler to various values as shown in Table 1 below.

However, depending on the type of the binder resin and the filler, the stirring time of the liquid binder and the filler mixture was in the range of about 1 hour to 3 hours. The carbon nanotubes (CNT) having an average diameter of 10 nm and an average length of 10 μm were used, and graphite having a carbon content of 99% or more and a diameter of 1 to 10 μm was used.

division
Liquid binder Filler mixture Electrical
characteristic Binder resin Organic solvent Heat-radiating filler Organic solvent Example 2 SBR 800g 600 g of toluene
Xylene 600g 150 g of Al ₂ O ₃ ,
100 g of BN, 100 g of SiC 600 g of toluene Insulation Example 3 SBS 800g 800 g of toluene
400 g of cyclohexane 150 g of Al ₂ O ₃ ,
BN 100 g, BeO 50 g Xylene 600g Insulation Example 4 EPDM 800g Toluene 1200 g AlN 250 g Normal hexane 600 g Insulation Example 5 SBR 800g Toluene 1200 g CNT 120g Toluene 840 g conductivity Example 6 SBS 800g 600 g of toluene
Xylene 600g CNT 120g
Cu 200g Xylene 900g conductivity Example 7 EPDM 800g Toluene 1200 g Ag 120g 600 g of toluene conductivity Example 8 SIS 800g Toluene 1200 g Graphite 800g 600 g of toluene conductivity Example 9 SEBS 800g 800 g of toluene
Xylene 400g CNT 250g
Graphite 400g 700 g of toluene
Xylene 500g conductivity

[Test Example]

1. Heat dissipation test

First, the heat radiation effect of the elastic coating composition of Example 1 was tested using LEDs for illumination (model names: LH-8K-E27 and LH-16K-E27, manufactured by Huawei) having capacities of 8W and 16W. In the test method, the elastic paint prepared according to Example 1 was applied to the surface of the heat sink of the LED 1 or 2 times with a brush to form a film having a thickness of about 100 to 200 mu m, Sufficiently dried. Then, the LED bulb was turned on and the temperature of the main part of the LED was measured every hour for 24 hours from the lapse of one hour after the lamp was turned on.

At this time, the temperature was measured at the check point 1 of the heat sink, the check point 2 of the heat sink, and the check point 3, and the temperature was measured with a model name of DataChart 2000 ( Monach) was used. The input power was 220V, 60Hz, and the ambient temperature was 28 ℃ and the humidity was 50%.

On the other hand, as the comparative example, the initial state, that is, the elastic paint of the present invention was applied to the same 8W and 16W LEDs (model name: LH-8K-E27 and LH-16K-E27, The temperature was measured in the same manner as in the above test method in the uncoated state, and the average values of the temperatures measured in each time period are shown in Table 2 below.

division 8 W Using LEDs Using 16 W LED Measuring position Example 1 Comparative Example Difference Example 1 Comparative Example Difference Ambient temperature 28 ℃ 28 ℃ none 25 ℃ 25 ℃ none Check point 1 54 ℃ 47 C -7 ° C 55 ° C 47 C -8 ° C Check point 2 53 ℃ 46 ° C -7 ° C 54 ℃ 45 ° C -9 ° C Check point 3 55 ° C 48 ° C -7 ° C 57 ℃ 50 ℃ -7 ° C

On the other hand, the heat radiation effects of the elastic coating compositions of Examples 2 to 9 were also tested. The test method was the same as the test method of Example 1 except that Power LED (manufacturer: Daejin DMP) having a capacity of 22 W was used. The temperature difference between the experimental results and the comparative example is calculated and the average values are shown in Table 3 below.

division Temperature drop effect Example Check point 1 Check point 2 Check point 3 Example 2 -9 ° C -10 ° C -8 ° C Example 3 -3 ℃ -4 ° C -3 ℃ Example 4 -4 ° C -4 ° C -4 ° C Example 5 -7 ° C -9 ° C -7 ° C Example 6 -7 ° C -8 ° C -6 ° C Example 7 -4 ° C -5 ℃ -4 ° C Example 8 -5 ℃ -7 ° C -5 ℃ Example 9 -7 ° C -8 ° C -6 ° C

As can be seen from the test results shown in Tables 2 and 3, when the elastic paint according to the present invention is applied to a typical LED heat sink, there is a distinct temperature drop effect of about -3 캜 to -10 캜 Respectively.

2. Insulation test

Coatings each having a thickness of 300 mu m, 450 mu m, and 500 mu m were formed using the elastic paint of Examples 1 to 4 using the insulating filler, and each of these coatings was subjected to an impact withstand voltage (manufacturer: HIPOTRONICS-ROBINSON) And the results are shown in Table 4 below.

division 100 탆 film 200 mu m coating 300 mu m coating Example 1 11,000 Volts 14,000 Volt 17,000 Volts Example 2 10,000 Volts 13,000 Volts 16,000 Volts Example 3 11,000 Volts 14,000 Volt 18,000 Volt Example 4 12,000 Volts 15,000 Volts 18,000 Volt

3. Conductivity test

Using the elastic paints of Examples 5 to 9 using the conductive filler, three square coating films (samples 1 to 3) each having a width of 1 cm, a length of 1 cm, and a thickness of 100 占 퐉 were formed on the insulating substrate, The results are shown in Table 5 below.

division Sample 1 Sample 2 Sample 3 Example 5 4,800 Ω 4.200 Ω 3,500 Ω Example 6 3,800 Ω 3,500 Ω 2,700 Ω Example 7 4,200 Ω 3,800 Ω 3,200 Ω Example 8 150 Ω 120 Ω 80 Ω Example 9 50 Ω 30 Ω 8 Ω

4. Elasticity test

The elastic paints prepared according to Examples 1 to 9 were applied to the silicone rubber plate having a thickness of 1 cm each twice with a brush and sufficiently dried for about 24 hours and then the silicone rubber plate was rotated 180 degrees or more 100 times And a repeated bending test was performed.

As a result of the test, the coating film coated with the elastic paint maintained the initial state as it had the same elasticity as that of the rubber plate, and no cracks occurred in the coating film, or a phenomenon in which the solid component such as a filler disappeared did not occur at all.

Claims (1)

800 parts by weight of toluene and 400 parts by weight of cyclohexane were mixed with 800 parts by weight of SBS (Styrene Butadiene Styrene), 600 parts by weight of xylene, 150 parts by weight of aluminum oxide (Al ₂ O ₃ ) and 100 parts by weight of boron nitride (BN) And 50 parts by weight of beryllium oxide (BeO) are mixed to form a mixture of filler mixtures.