High-performance heat-insulating materials

Patent metadata

Field	Value
Publication number	US-10119775-B2
Application number	US-201214232440-A
Country	US
Kind code	B2
Filing date	Jul 12, 2012
Priority date	Jul 13, 2011
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

The present invention relates to a heat-insulating material, in particular in the form of a solid foam, based on silica particles of submicron porosity, this material incorporating two different ranges of porosities, advantageously including a first range consisting of (macro)pores with diameters of between 10 microns and 3 mm, and a second range consisting of submicron pores with diameters greater than 4 nm and less than 300 nm, the pore volume of said submicron pores being at least 1 cm3/g and the mass per unit volume of said insulating material being less than 300 kg/m3, and also relates to the process for obtaining the same.

First claim

The invention claimed is:

1. A heat-insulating material, formed from silica particles of submicron porosity,
wherein the heat-insulating material is a solid silica foam incorporating two different ranges of porosities, including:
a first range of macropores with diameters of between 10 microns and 3 mm; and

a second range of submicron pores with diameters greater than 4 nm and less than 300 nm,
wherein the pore volume for the submicron pores ranges from 1 to 1.5 cm 3 /g, and the pore volume for the macropores is from 3 to 15 cm 3 /g,
wherein the heat-insulating material has a mass per unit volume of the heat-insulating material is less than 300 kg/m 3 , and
wherein the silica particles of submicron porosity do not comprise aerogels, the silica particles of submicron porosity have submicron pores with diameters of greater than 4 nm, and the silica particles of submicron porosity have a specific surface area less than or equal to 500 m 2 /g.

2. The heat-insulating material of claim 1 , wherein the heat-insulating material is obtained from a mixture comprising:
water or an aqueous foam,
silica particles of submicron porosity, incorporated into the aqueous foam or the water in the form of a dispersion/suspension, the silica particles having a specific surface area S of greater than 5 m 2 /g, and,
optionally an organic binder and/or a mineral binder, and/or a surfactant and/or a pore-forming agent and/or a reinforcement.

3. The heat-insulating material of claim 1 , wherein the silica particles are based on an amorphous silica.

4. The heat-insulating material of claim 1 , wherein the heat-insulating material has a heat conductivity of less than 40 mW/m·K.

5. A heat insulation for buildings, comprising the heat-insulating material of claim 1 .

6. The heat-insulating material of claim 2 , wherein the silica particles having a specific surface area S is greater than 50 m 2 /g.

7. The heat-insulating material of claim 3 , wherein the amorphous particles are precipitate silica, pyrogenic silica, fumed silica or a silica gel.

8. The heat-insulating material of claim 1 , wherein the pore volume for the macropores is in a range of from 5 to 15 cm 3 /g.

9. The heat-insulating material of claim 4 , wherein the heat-insulating material has a heat conductivity of less than 25 mW/m·K.

10. The heat-insulating material of claim 1 , wherein the silica particles of submicron porosity have a specific surface area greater than 5 m 2 /g.

11. The heat-insulating material of claim 1 , wherein the silica particles of submicron porosity have a specific surface area greater than 30 m 2 /g.

12. The heat-insulating material of claim 1 , wherein the silica particles of submicron porosity have submicron pores with diameters of greater than 7 nm.

Assignees

• Dekoninck Alexandra
• Denkov Nikolai Denkov
• Lesov Ivan Igorov
• Tcholakova Slavka Stoyanova
• Golemanov Konstantin Nikolaev
• Saint Gobain Isover

Inventors

• Dekoninck Alexandra
• Denkov Nikolai Denkov
• Lesov Ivan Igorov
• Tcholakova Slavka Stoyanova
• Golemanov Konstantin Nikolaev

Classifications

• C08J2205/042

  Nanopores, i.e. the average diameter being smaller than 0,1 micrometer · CPC title

• C04B2111/28

  Fire resistance, i.e. materials resistant to accidental fires or high temperatures · CPC title

• C08J2205/048

  Bimodal pore distribution, e.g. micropores and nanopores coexisting in the same foam · CPC title

• C04B2201/20

  for the density · CPC title

• C08J9/0066

  Use of inorganic compounding ingredients · CPC title