Thermal insulation material comprising precipitated silica
View Patent ↗A thermal insulation material comprising a precipitated silica having a modified tapped density of less than or equal to 70 g/l.
1. A thermal insulation material, comprising:
from 30 to 95% by weight of a comminuted and classified precipitated silica having a modified tapped density of 10 to 50 g/l; and
from 5 to 70% by weight of opacifier material.
2. The material of claim 1 , wherein
a) a d 50 -value of the precipitated silica is from 150 to 2000 nm,
b) a d 90 -value of the precipitated silica is from 500 to 7000 nm, and
c) a silanol group density of the precipitated silica is from 2.5 to 8 OH/nm 2 .
3. The material of claim 1 , wherein a BET-surface area of the precipitated silica is from 100 to 350 m 2 /g.
4. The material of claim 1 , wherein the precipitated silica has at least one property selected from the group consisting of
a loss on drying is from 1.5 to 8% by weight, and
a loss on ignition is from 1.5 to 9% by weight.
5. The material of claim 1 , wherein a pH-value of the precipitated silica is from 4 to 9.
6. The material of claim 1 , wherein a content of the precipitated silica is from 40 to 80 wt.-% based on a weight of the thermal insulation material.
7. The material of claim 1 , further comprising:
a particulate insulating filler material.
8. The material of claim 7 , wherein an amount of the particulate insulating filler material is from greater than 0 to 70 wt.-%, based on a weight of the thermal insulation material.
9. The material of claim 1 , further comprising
a binder material.
10. The material of claim 9 , wherein an amount of the binder material is from greater than 0 to 70 wt.-%, based on a weight of the thermal insulation material.
11. The material of claim 1 , wherein a thermal conductivity at a mean temperature of 300K of the precipitated silica is less than 0.05 W/mK at a reduced gas pressure.
12. A loose filled thermal insulation, a sheet, a block, or a vacuum isolation system, comprising the material of claim 1 .
13. The material of claim 2 , wherein a BET-surface area of the precipitated silica is from 100 to 350 m 2 /g.
14. The material of claim 2 , wherein
the precipitated silica has at least one property selected from the group consisting of
a loss on drying is from 1.5 to 8% by weight, and
a loss on ignition is from 1.5 to 9% by weight.
15. The material of claim 3 , wherein
the precipitated silica has at least one property selected from the group consisting of
a loss on drying is from 1.5 to 8% by weight, and
a loss on ignition is from 1.5 to 9% by weight.
16. The material of claim 2 , wherein the pH-value of the precipitated silica is from 4 to 9.
17. The material of claim 3 , wherein the pH-value of the precipitated silica is from 4 to 9.
18. The material of claim 4 , wherein the pH-value of the precipitated silica is from 4 to 9.