Insulating heat dissipation coating composition and insulating heat dissipation unit formed using the same
An insulating heat dissipation coating composition including a coating layer-forming component including a subject resin, and an insulating heat dissipation filler. Therefore, the coating composition may have excellent thermal conductivity and excellent thermal emissivity, and therefore an insulating heat dissipation coating layer which exhibits excellent heat dissipation performance and has insulating property may be formed. In addition, the heat dissipation coating layer formed thereby has a very excellent adhesive strength to a surface to be coated so as to significantly prevent peeling of the coating layer during use, and to maintain durability of the coating layer even against a physical or chemical stimulus such as external heat, organic solvent, moisture or shock, which is generated after the coating layer is formed.
1. An insulating heat dissipation coating composition, comprising:
a coating layer-forming component including a subject resin and a curing agent which is included in an amount of 40 to 80 parts by weight based on 100 parts by weight of the subject resin, wherein the curing agent comprises a first curing agent comprising an aliphatic polyamine-based curing agent comprising polyethylene polyamine, and a second curing agent comprising one or more types selected from the group consisting of an aromatic polyamine-based curing agent, an acid anhydride-based curing agent and a catalytic curing agent, at a weight ratio of 1:0.5 to 1.5 of the first curing agent to the second curing agent;
an insulating heat dissipation filler included in an amount of 25 to 70 parts by weight based on 100 parts by weight of the subject resin; and
a pigment in an amount of 10 to 60 parts by weight based on 100 parts by weight of the subject resin,
wherein the insulating heat dissipation filler comprises silicon carbide, and
wherein the insulating heat dissipation filler has an average particle diameter of 10 nm to 15 μm and a ratio of D50 to D97 of 1:4.5 or less.
2. The composition of claim 1 , wherein the subject resin includes one or more types selected from the group consisting of polyethylene, polypropylene, polystyrene, polyvinyl chloride, a polyacrylonitrile resin, acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN), an acrylic resin, a methacrylic resin, a polyamide, polyester, a polycarbonate, polyphenylene sulfide, a polyamideimide, polyvinylbutyral, polyvinylformal, polyhydroxypolyether, a polyether, polyphthalamide, a phenoxy resin, polyurethane, a nitrile butadiene resin, an urea-based resin (UF), a melamine-based resin (MF), a unsaturated polyester resin (UP), an epoxy resin and a silicone resin.
3. The composition of claim 1 , wherein the subject resin includes a compound represented by Formula 1 below:
R 1 and R 2 are each independently a hydrogen atom, a C1 to C5 linear alkyl group or a C3 to C5 branched alkyl group, R 3 and R 4 are each independently a hydrogen atom, a C1 to C5 linear alkyl group or a C3 to C5 branched alkyl group, and n is a rational number such that the compound represented by Formula 1 has a weight average molecular weight of 400 to 4000.
4. The composition of claim 1 , wherein a thermal emissivity according to the following method of evaluating thermal emission is 30% or more:
In a closed system at 25° C. and a humidity of 50%, a heat dissipation unit including an insulating heat dissipation coating layer having a thickness of 25 μm, formed by treatment with an insulating heat dissipation coating composition is placed on a top surface of an aluminum plate with a thickness of 1.5 mm and a size of 35 mm×34 mm (of width×length) to have a surface area in the middle of the bottom of the dissipation unit of 4 cm 2 , and to be closely adhered to a heat source at 88° C., and after 90 minutes, a temperature is measured at the site 5 cm above the center of the heat dissipation unit, and a temperature is measured only on an aluminum plate on which a heat dissipation coating layer is not formed by the same method as described above to determine thermal emissivity according to Mathematical Formula 1 below:
Heat
emissivity
(
%
)
=
{
(
Temperature
at
site
5
cm
above
the
center
of
heat
dissipation
unit
(
°
C
.
)
Temperature
at
site
5
cm
above
the
center
of
non
‐
coated
heat
dissipation
unit
(
°
C
.
)
)
-
1
}
⨯
100
(
%
)
[
Mathematical
Formula
1
]