KR102052386B1 - composition of Heat-radiating paint - Google Patents

Abstract

The present invention relates to a heat-dissipating coating composition, comprising a polyurethane resin, a wetting agent or a dispersion stabilizer, a leveling agent, an antifoaming agent, a fluidity adjusting additive, a solvent having a curing temperature of 60 ℃ to 80 ℃, dispersed in the solvent and averaged It provides a heat-dissipating paint composition composed of a filler having a particle diameter of 0.01㎛ ~ 10㎛ and is applied after drying on the substrate to improve the thermal conductivity of the paint to enable stable use, miniaturization and ultra-thinning of electrical and electronic products, etc. In addition, it is possible to apply to any base material such as plastic.

Description

Composition of Heat-radiating paint

The present invention relates to a heat-dissipating paint composition, and more particularly, to improve the thermal conductivity of the paint to enable stable use and miniaturization and ultra-thinning of electrical and electronic products, as well as heat radiation that can be applied to any base material such as plastic It relates to a coating composition.

Excellent heat dissipation effect is required as various electric and electronic devices are miniaturized and ultra-thin, but due to small size and ultra-thin, it is not possible to secure enough space to install heat dissipation fins, which reduces the heat generation area of the heat dissipation fins. Occurred, and in severe cases, there was a problem that an explosion or fire of the device occurred.

In other words, the devices used in electrical and electronic devices generate heat as power is supplied. Such heat must be quickly dissipated to the outside through heat sinks and heat sink fins. Recently developed devices have a very thin thickness of the heat sink fins. Since there is not enough space to install the lamp, the generated heat is continuously heated while collecting the inside of the housing of the device, causing problems such as malfunction.

Accordingly, Korean Patent Publication No. 2012-0046523 discloses a heat dissipation coating composition including 130170 parts by weight of an inorganic particle, 80120 parts by weight of a binder, 37 parts by weight of a dispersant, and 4060 parts by weight of a solvent. At this time, the inorganic particles exhibiting heat dissipation effect are jade, cerite, cordierite, germanium, iron oxide, mica, manganese dioxide, silicon carbide, macsumite, carbon, copper oxide, cobalt oxide, nickel oxide, antimony pentoxide, tin oxide, and oxidation Chrome, silica, alumina, magnesium oxide, titania, zirconia, zinc oxide, barium titanate, zirconium titanate, strontium titanate and the like are disclosed.

However, even with these prior arts, there is a problem in that heat dissipation characteristics required for ultra-thin electronic products cannot be matched.

Meanwhile, in the case of using graphite or graphene as a carbon-based material, a coating layer formed by wet coating can obtain heat dissipation effect due to the graphene, but due to thermal conductivity in the horizontal direction of graphene itself, the heat dissipation effect This is limited to two-dimensional, and due to the high price (高 이) is the cause of raising the price of electronic products is difficult to apply universally.

An object of the present invention for solving the above problems, by using a carbon-based material mixed with other thermally conductive material as a filler, to have a good heat dissipation effect at a low cost by minimizing the amount used The purpose is to prevent economic and structural difficulties in the implementation of ultra-thin electronic products.

In addition, by using a mixture of metal oxides, ceramics, and the like, which have excellent heat transfer characteristics with respect to the two-dimensional heat conduction characteristics of the carbon-based material, the thermal conductivity is removed, and the contact area between the fillers is improved to improve the thermal conductivity effect. There is a purpose.

In addition, it is another object to provide a heat-dissipating coating composition that can be applied to any base material such as plastic by using a low-temperature curing type urethane resin.

A feature of the present invention for achieving the above object is a urethane solvent comprising a polyurethane resin, a wetting agent or a dispersion stabilizer, a leveling agent, an antifoaming agent, a fluidity adjusting additive, dispersed in the urethane solvent, the average particle diameter 0.01㎛ It exists in the heat-dissipating coating composition comprised including the filler which is -10 micrometers, and a hardening | curing agent, and after apply | coating on a base material.

The filler is silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), silica (Silica), zirconium (Zr), magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), oxide One or a mixture of tin (SnO), silicon carbide (SiC), nitride (Si ₃ N ₄ , AlN, BN), graphite, graphene, carbon nanotubes (CNT) It is preferable to use a carbon-based material (SiC), graphite, graphene, carbon nanotubes of the first filler consisting of one or a mixture thereof and a mixture of other fillers other than these, preferably as the carbon-based material The configured first filler uses an average particle diameter of 0.01 μm to 10 μm, and other fillers use an average particle diameter of 0.01 μm to 1 μm.

According to the present invention having the configuration as described above, by providing a paint having excellent heat dissipation effect at low cost, economic and structural difficulties do not occur in the implementation of ultra-thin electronic products, the stability of the ultra-thin electronic products is improved and the form is diversified and In addition, the cost is reduced.

In addition, there is another object to improve the thermal conductivity effect by removing the thermal conductivity direction by the mixed use of the metal oxide, ceramics and the like in the horizontal thermal conductivity characteristics by the carbon-based material, and improve the contact area between the fillers.

In addition, by using a low-temperature curing type urethane resin can be applied to any base material such as plastic, there is an effect that it is possible to form electronic products of various materials.

1 is a view showing the physical property test results of the heat dissipation coating composition of the present invention
Figure 2 is a view showing the thermal conductivity measurement results of the heat dissipation coating composition of the present invention
3 is a view showing the thermal conductivity measurement equipment of the present invention

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

The heat dissipating coating composition according to the present invention is a urethane solvent comprising a polyurethane resin, a wetting or dispersing stabilizer, a leveling agent, an antifoaming agent, a fluidity adjusting additive, and dispersed in the urethane solvent, the average particle diameter is 0.01㎛ ~ 10㎛ It comprises a filler and a curing agent, is formed and circulated in a liquid state and then cured or dried at 60-80 ° C. after application on a substrate.

In the above wetting agent or dispersion stabilizer is an additive for wetting and dispersing non-aqueous paint, 0.5 ~ 2% based on the total weight of the heat-dissipating paint composition, in the embodiment of the present invention brand name CFC-6010 (manufactured by Chungwoo CFC Co., Ltd.) or The brand name CFC-6330N (made by Chungwoo CFC Co., Ltd.) is used, and it is used for the dispersion | distribution of a filler and prevention of reaggregation of a filler. Examples include polymethyl acrylate (PMA), xylene, butylacetate, solvent (DIBK / BC / Anone), and the like.

The leveling agent is mainly composed of a polymer acrylic ester copolymer and has a solid content of 52 ± 2%, and is used in an amount of 0.1 to 2% by weight based on the total weight of the coating composition, thereby improving the leveling effect of the coating material, preventing the cruttering of the coating film, and the substrate. It has the effect of improving adhesion, and in the embodiment of the present invention, the brand name CFC-89 (manufactured by Chungwoo CFC Co., Ltd.) is used.

Antifoaming agents (surfactants) include modified polysiloxane copolymers, modified olefin compounds with a solid content of 98%, polyether modified polysiloxanes with a solid content of at least 94%, and are used in an amount of 0.1 to 2% by weight based on the total weight of the coating composition. When the coating on the substrate has a function to facilitate the wetting on the substrate, in the embodiment of the present invention, trade name CFC-166H (produced by Chungwoo CFC), brand name CFC-144B (produced by Chungwoo CFC), It is used alternatively from CFC-733E (manufactured by Chungwoo CFC Co., Ltd.).

The fluidity adjusting additive is based on a low molecular weight modified urea having a solid content of 52 ± 2% and is used to secure the fluidity of a high viscosity material based on a total weight of the coating composition of 0.1 to 2% by weight, in the embodiment of the present invention CIMA-1400 Cheongwoo CFC Co., Ltd. is used.

Urethane solvent having such a configuration is used 40-70% by weight based on the total weight of the paint composition.

The filler is a first filler composed of one or a mixture thereof selected from silicon carbide (SiC), graphite, graphene, CNT, silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), silica (Silica), a second filler composed of one or a mixture thereof selected from zirconium (Zr), magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃₎ , tin oxide (SnO), and silicon nitride (Si ₃ N ₄ ) And a third filler composed of one or a mixture thereof selected from aluminum nitride (AlN) and boron nitride (BN), and the first filler composed of the carbon-based material has an average particle diameter of 0.01 μm to 10 μm. The second and third fillers are those having an average particle diameter of 0.01 μm to 1 μm.

In addition, since the filler and the urethane solvent mixture are coated on a substrate composed of any one of aluminum, copper, metal alloy, and plastic, a diluent and a curing agent are used in this coating process, and the diluent is a urethane solvent, a filler, a diluent and 3 to 10% by weight, based on the total weight of the mixture, which contains all of the curing agent, and 3 to 50% by weight, based on the total weight of the mixture, which contains both the urethane solvent and the filler, diluent, and curing agent.

In this case, the diluent may be one selected from butyl acetate (BA), benzene (Benzene) or a mixture thereof, and the curing agent may include one or a mixture thereof selected from aliphatic dihydric alcohol and polyisocyanate.

In this process, when silicon carbide (SiC) and silicon nitride (Si ₃ N ₄ ) are used with particles having a size of 1 to 3 μm, the particle size is preferably 0.1 μm to 0.01 μm because the particles are protruded to the surface after application. Do.

And, graphite is preferably 1㎛ ~ 10㎛ size and 10㎛ or more surface roughness after application is bad.

In addition, the particle size of the filler can be adjusted based on the surface roughness and the thickness and space of the substrate used, but is preferably 1㎛ ~ 0.01㎛.

The urethane solvent and the filler are stirred at room temperature, mixed with a diluent and a curing agent, and applied to a substrate, followed by heating at 80 ° C. for 30 minutes to dry, or curing.

Embodiments of the present invention configured as described above will be described in more detail below.

[Comparative Example]

As a base material, the aluminum disc was 12 mm wide, 7 mm long and 1 mm high, and the thermal conductivity measurement result (TPS 500S HOT-DISK method) was 135.5 W / mK.

Example 1

Urethane solvent (2), SiC (500 g), AlN (300 g), BN (200 g), diluent (3-10 wt% of the total weight of the paint composition), curing agent (3-50 wt% of the total weight of the paint composition) After stirring for 1 hour to 1 hour and 30 minutes, and applied to the aluminum disc of Comparative Example 1 and cured at 80 ° C. for 30 minutes, the thermal conductivity measurement result (TPS 500S HOT-DISK method) is 142.5W / mK, the coating property is good, Surface roughness was found to be bad.

Example 2

Urethane solvent (2), AlN (500 g), BN (300 g), MgO (200 g) diluent (less than 10% of the total capacity), curing agent (50% of the total capacity) after stirring for 1 hour to 1 hour 30 minutes at room temperature, After coating the aluminum disc of Comparative Example 1 and curing it at 80 ° C. for 30 minutes, the thermal conductivity measurement result (TPS 500S HOT-DISK method) was 144 W / mK, and the coating property was good, and the surface roughness was good and the surface was smooth. .

Example 3

Urethane solvent (2 liters), AlN (500 g), BN (300 g), MgO (200 g), graphite (500 g) diluent (within 10% of full capacity), hardener (50% of full capacity) 1 hour at room temperature After stirring for 30 minutes, the resultant was applied to the aluminum disc of the comparative example, cured at 80 ° C. for 30 minutes, and the thermal conductivity measurement result (TPS 500S HOT-DISK method) was 162 W / mK. The coating property was good, and the surface roughness was normal.

Example 4

Under the same conditions as in Example 3, the stirring time was operated for 8 to 10 hours using a ball mill, and the coating property and surface roughness were good, and the thermal conductivity was improved by about 10% to 162 W / mK> 179 W / mK.

Therefore, when stirring for 8-10 hours using a ball mill as described above, SiC, Si ₃ N ₄ , AlN, BN, MgO, Al ₂ O _{3 ,} graphite material can be used as a filler.

Example 5

After setting the aluminum disc of Comparative Example 1 at 50 ° C. and configuring the equipment as shown in FIG. 3, placing the measurement material on a heat source plate and measuring the result, the temperature measurement result was 40.9 ° C. after 30 minutes, and 40.9 ° C. after 45 minutes. 2 was number 1).

Example 6

The sample of Example 1 was set at 50 ° C., and the temperature measurement result after 30 minutes using the equipment of FIG. 2 was 43.5 ° C., and after 4 minutes, it was 44.8 ° C. (No. 2 in FIG. 2).

Example 7

The raw material of plastic (cell phone case) was set at 50 ° C (same level), and after 30 minutes, it was 41.1 ° C and 41.5 ° C (number 3 in Fig. 2) after 45 minutes.

Example 8

The sample of Example 1 was set to 50 ° C. (same level), and after 30 minutes, it was 42.3 ° C., and after 4 minutes, it was 42.3 ° C. (No. 4 in FIG. 2).

On the other hand, the physical property test results of the heat-dissipating coating composition of the present invention as shown in Figure 1 confirmed that there is no abnormality in all items such as hardness, impact resistance, corrosion resistance, alkali resistance, heat resistance, etc., the results of Figure 1 The result according to 4.

Example 9

Urethane solvent 200g, SiC 40g, AlN 35g, BN 30g, MgO 20g, Al ₂ O ₃ 10 g, graphite 30 g, diluent 30 g, curing agent 30 g after stirring for 1 hour to 1 hour 30 minutes at room temperature, and applied to the aluminum and plastic discs of Comparative Example 1, respectively, cured at 80 ℃ 30 minutes, set to 50 and room temperature After 45 minutes of measuring the temperature of the surface of the substrate, and the known heat dissipation sheet or copper copper plate respectively attached to the substrate, or after the heat-resistant grease applied to the result of measuring the temperature as shown in Figure 2 the coating material of the present invention It can be seen that the thermal conductivity is excellent.

Setting the measurement temperature to 50 ° C is measured by setting and predicting the internal heat generation of the smartphone at 50 ° C, the correlation between the measurement temperature and the heat dissipation effect is insufficient.

On the other hand, SiC has a high hardness, high heat resistance, corrosion resistance, high thermal conductivity, and a relatively small coefficient of thermal expansion.

Aluminum nitride (AIN) has very high thermal conductivity and good electrical insulation properties.

Boron Nitride (BN) has high thermal conductivity and high thermal shock resistance, and does not crack or break even after repeated rapid heating and rapid cooling to about 1500, and is excellent in corrosion resistance to most organic solvents. It does not react with melts such as aluminum, zinc, lead, tin, nickel, manganese, germanium, gallium, silicon and glass, and has excellent high temperature lubricity, low coefficient of friction, light weight, and excellent machinability.

Graphite has the property of increasing strength up to about 2 times with increasing temperature, excellent electrical conductivity, corrosion resistance to chemicals, light weight, and excellent workability.

Claims (3)

Urethane solvents comprising polyurethane resins, wetting or dispersion stabilizers, leveling agents, antifoaming agents, rheology modifiers;
Curing agents comprising polyisocyanates;
A first filler composed of one or a mixture of silicon carbide (SiC), graphite, graphene, and CNT having an average particle diameter of 0.01 μm to 10 μm and dispersed in the solvent, and an average particle diameter of 0.01 μm to 1 μm Among (Ag), copper (Cu), aluminum (Al), magnesium (Mg), silica (Silica), zirconium (Zr), magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃₎ , tin oxide (SnO) A second filler composed of one or a mixture thereof and one selected from silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN) and boron nitride (BN) having an average particle diameter of 0.01 μm to 1 μm. A filler including three fillers;
A heat-dissipating paint composition, characterized in that it comprises a cured at 60-80 ℃ after coating on the substrate. delete delete

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