High-performance heat-insulating materials

1. A heat-insulating material, formed from mineral particles comprising submicron pores,

wherein the heat-insulating material incorporates two different ranges of porosities, including:

a first range of macropores having diameters of between 10 μm and 3 mm; and

a second range of submicron pores having diameters greater than 4 nm and less than 1 μm, the pore volume of said submicron pores being at least 0.5 cm 3 /g, and

wherein the heat-insulating material has a mass per unit volume of less than 300 kg/m 3 .

2. The heat-insulating material of claim 1 , wherein the heat-insulating material is predominantly inorganic.

3. The heat-insulating material of claim 1 , wherein the heat-insulating material is obtained from a mixture comprising:

an aqueous foam or water;

mineral particles of submicron porosity, wherein said particles are incorporated into the aqueous foam or the water in the form of a dispersion/suspension and said particles have a specific surface area S of greater than 5 m 2 /g; and

optionally at least one additive selected from the group consisting of an organic binder, a mineral binder, a surfactant, and a reinforcement.

4. The heat-insulating material of claim 3 , wherein the mixture further comprises a pore-forming agent.

5. The heat-insulating material of claim 1 , wherein the mineral particles are based on silicon oxides and/or derivatives thereof, and/or a clay, and/or the mineral particles are based on dolomites and/or carbonates.

6. The heat-insulating material of claim 1 , wherein the mineral particles are silicates or carbonates of an alkali metal or an alkaline-earth metal.

7. The heat-insulating material of claim 1 , wherein the pore volume of the submicron pores is from 0.5 to 3 cm 3 /g and the pore volume of the macropores is greater than 1 cm 3 /g.

8. The heat-insulating material of claim 7 , wherein the pore volume of the macropores is greater than 3 cm 3 /g.

9. The heat-insulating material of claim 7 , wherein the pore volume of the macropores is from 5 to 15 cm 3 /g.

10. The heat-insulating material of claim 1 , having a heat conductivity of less than 40 mW/m·K.

11. The heat-insulating material of claim 1 , wherein the mineral particles are clay particles.

12. The heat-insulating material of claim 1 , wherein the mineral particles are carbonate particles of an alkali metal or an alkaline-earth metal.

13. The heat-insulating material of claim 1 , having a heat conductivity of less than 35 mW/m·K.

14. The heat-insulating material of claim 1 , having a heat conductivity of less than 30 mW/m·K.

15. A process, comprising:

heat-insulating a wall of a building with the heat-insulating material of claim 1 ,

wherein the heat-insulating material is in the form of a panel, or in the form a layer applied to a board, or impregnated or spread onto a web, or combined with a fiber matrix or another layer or in the form of granules, blocks, layers, projections, moldings.

16. A process for manufacturing the heat-insulating material of claim 1 , the process comprising:

forming a mixture comprising mineral particles having a specific surface area S of greater than 5 m 2 /g and having a pore volume of at least 0.5 cm 3 /g in the porosity range between 4 nm and 1 micron;

forming a foam comprising the mineral particles;

putting the foam in form; and

at least partial drying of the foam.

17. The process of claim 16 , wherein the mixture further comprises at least additive selected from the group consisting of a pore-forming agent, a surfactant, an organic binder, an inorganic binder, a rheological agent, and a reinforcement.

18. The process of claim 16 , further comprising, after the drying:

heat treating the heat-insulating material.

19. The process of claim 16 , wherein a foaming is performed by direct foaming of the mixture or by incorporating the mixture into a preformed aqueous foam.

20. The process of claim 16 , further comprising, after the drying:

hydrophobizing the heat-insulating material.