Composite material
A composite material according to the present invention includes a solid portion including inorganic particles and a resin. The composite material has a porous structure including a plurality of voids surrounded by the solid portion. In the composite material, a value P 1 determined by the following equation (1) is 6 or more. In the equation (1), a heat conductivity is a value measured for one test specimen in a symmetric configuration according to an American Society for Testing and Materials (ASTM) standard D5470-01. P 1 =(the heat conductivity [W/(m·K)] of the composite material/an amount[volume %] of the inorganic particles)×100 Equation (1).
1 . A composite material comprising:
a body comprising:
a plurality of inorganic particles;
a plurality of first resin particles comprising a first resin; and
a second resin different from the first resin, wherein
the first resin particles of the plurality of first resin particles have a hollow structure, the second resin is present around the plurality of first resin particles,
at least a portion of the plurality of inorganic particles are in contact with the first resin particles of the plurality of first resin particles,
the inorganic particles of the plurality of inorganic particles are present on wall surfaces of the second resin facing the first resin particles,
a value P1 determined by the following equation (1) is 6 or more:
P
1
=
(
a
heat
conductivity
[
W
/
(
m
·
K
)
]
of
the
composite
material
/
an
amount
[
volume
%
]
of
the
inorganic
particles
)
×
100
,
Equation
(
1
)
where the heat conductivity is a value measured for one test specimen in a symmetric configuration according to an American Society for Testing and Materials (ASTM) standard D5470-01.
2 . The composite material according to claim 1 , wherein the value P 1 is 7.5 or more.
3 . The composite material according to claim 1 , wherein
a heat transmission path is formed of the plurality of inorganic particles in contact with each other.
4 . The composite material according to claim 1 , wherein a value P 0 determined by the following equation (2) is 30 or more:
P 0 =(an average diameter [μm] of voids in the second resin within which the first resin particles of the plurality of first resin particles are accommodated/an average particle diameter [μm] of the inorganic particles)×(a void ratio [volume %]/100) Equation (2).
5 . The composite material according to claim 4 , having a heat conductivity of 0.5 W/(m·K) or more.
6 . The composite material according to claim 1 , wherein the first resin particles of the plurality of first resin particles have substantially similar outer shapes.
7 . The composite material according to claim 6 , wherein the first resin particles of the plurality of first resin particles are substantially spherical.
8 . The composite material according to claim 1 , wherein the composite material is a non-foam body.
9 . The composite material according to claim 1 , wherein
voids in the second resin within which the first resin particles of the plurality of first resin particles are accommodated have an average diameter of 50 μm to 5000 μm, and
the inorganic particles have an average particle diameter of 0.1 μm to 50 μm.
10 . The composite material according to claim 1 , wherein the inorganic particles of the plurality of inorganic particles have an aspect ratio of 1 or more and less than 50.
11 . The composite material according to claim 1 , wherein the first resin particles of the plurality of first resin particles are accommodated within voids in the second resin, and the composite material has a void ratio of 10 volume % to 60 volume %.