Heat insulating material, method for manufacturing same, and electronic equipment and automobile using same
A heat insulating material includes an aerogel that has macro-pores and meso-pores. A method for manufacturing a heat insulating material, including: a sol preparation step of adding a gelling agent into sodium silicate such that a molar ratio of the gelling agent relative to NaO 2 is 0.1 to 0.75, and adjusting a sol into which macro-pores are introduced by leaving unreacted Na and non-cross-linked oxygen in a siloxane skeleton; an impregnating and gelling step of impregnating a nonwoven fabric fiber structure with the sol to form a composite of hydrogel-nonwoven fabric fiber; a hydrophobizating step of mixing the formed composite of hydrogel-nonwoven fabric fiber with a silylating agent to modify a surface thereof; and a drying step of removing a liquid contained in the surface modified composite of hydrogel-nonwoven fabric fiber by drying under a temperature and pressure lower than respective critical values.
1. A heat insulating material comprising:
an aerogel that has macro-pores and meso-pores, wherein:
a fine pore distribution of the macro-pores is 1 to 10 μm and of the meso-pores is 2 to 50 nm,
the aerogel further includes pores having a fine pore distribution other than the macro-pores being 1 to 10 μm and the meso-pores being 2 to 50 nm, and
a peak of a fine pore distribution of a total pore volume is located between 50 nm and 10 μm.
2. The heat insulating material according to claim 1 , comprising:
the aerogel, wherein
an average fine pore diameter of the meso-pores is 20 to 40 nm, and
an average fine pore diameter of the macro-pores is 2 to 6 μm.
3. The heat insulating material according to claim 1 , wherein
the aerogel has 7 to 60 vol % of the macro-pores relative to a total fine pore volume, and 15 to 60 vol % of the meso-pores relative to the total fine pore volume.
4. The heat insulating material according to claim 1 , wherein
the aerogel is retained in a nonwoven fabric fiber.
5. The heat insulating material according to claim 1 , wherein
a thermal conductivity after compression is decreased by 5% or more relative to an initial thermal conductivity.
6. The heat insulating material according to claim 5 , wherein
a thermal conductivity after compression under 5 MPa is decreased by 5% or more relative to the initial thermal conductivity.
7. The heat insulating material according to claim 1 , wherein
the aerogel is a silica aerogel.
8. A piece of electronic equipment that uses the heat insulating material according to claim 1 between an electronic component with heat generation and a housing.
9. An automobile that uses the heat insulating material according to claim 1 between batteries.
10. A heat insulating material comprising:
an aerogel that has macro-pores and meso-pores, wherein:
a fine pore distribution of the macro-pores is 1 to 10 μm and of the meso-pores is 2 to 50 nm,
the aerogel further includes pores having a fine pore distribution other than the macro-pores being 1 to 10 μm and the meso-pores being 2 to 50 nm, and
a thermal conductivity after compression is decreased by 5% or more relative to an initial thermal conductivity.
11. The heat insulating material according to claim 10 , wherein
a thermal conductivity after compression under 5 MPa is decreased by 5% or more relative to the initial thermal conductivity.