Melamine resin foams with nanoporous fillers
The invention relates to open-cell melamine resin foams filled with nanoporous particles, especially aerogels or aerosils, and production and use of said foams.
1. A melamine resin foam comprising particles, said particles being nanoporous, wherein said melamine resin foam has a pore size in the range from 10 to 1000 μm, and wherein the nanoporous particles have a particle size (D 50 value) in the range from 0.1 to 100 μm and a porosity of 50 to 99%.
2. The foam according to claim 1 which is a melamine-formaldehyde resin.
3. The foam according to claim 1 which is a melamine-formaldehyde resin having a melamine-to-formaldehyde molar ratio in the range from 1:1.2 to 1:4.
4. The foam according to claim 1 comprising from 1% to 99% by volume of nanoporous particles or mixtures thereof.
5. The foam according to claim 1 wherein the particles are aerogels or aerosils.
6. The foam according to claim wherein the particles are inorganic.
7. The foam according to claim 1 wherein the particles are organic.
8. The foam according to claim 1 wherein the particles are organomodified.
9. The foam according to claim 1 wherein the nanoporous particles are SiO 2 aerogels having the following parameters:
density: from 30 to 300 g/L
particle diameter: from 0.1 to 100 μm
pore diameter: 0.1 to 500 nm.
10. The foam according to claim 1 further comprising an opacifier.
11. A process for producing the melamine resin foam according to claim 1 , said process comprising impregnating the melamine resin foam being impregnated with the particles and optionally thermocompressing the impregnated melamine resin foam thereafter.
12. A process for producing the melamine resin foam according to claim 1 , which comprises producing a mixture comprising at least one melamine-formaldehyde precondensate, at least one solvent, at least one blowing agent, and at least one nanoporous particle, foaming this mixture and the foam obtained being subsequently dried and optionally thermocompressed.
13. A melamine resin foam comprising particles, said particles being nanoporous, wherein said melamine resin foam has a pore size in the range from 10 to 1000 μm, and wherein the nanoporous particles have a particle size (D 50 value) in the range from 0.11 to 25 mm and a porosity of 50 to 99%.
14. The foam according to claim 13 wherein the nanoporous particles are SiO 2 aerogels having the following parameters:
density: from 30 to 300 g/L
particle diameter: from 0.11 to 25 mm
pore diameter: 0.1 to 500 nm.
15. The foam according to claim 13 wherein the nanoporous particles are SiO 2 aerogels having the following parameters:
porosity: 80 to 99
density: from 30 to <150 g/L
particle diameter: 0.15 to 22 mm (D 50 )
pore diameter: 0.1 to <100 nm.