Dynamically evacuable devices comprising organic aerogels or xerogels
The present invention relates to a dynamically evacuable, electrically operated device comprising a coherently evacuable region and a temperature-controllable useful region, which is thermally insulated from the ambient temperature by the coherently evacuable region, and also a means for actively maintaining a vacuum, such that the pressure in the coherently evacuable region of the device is constantly within a defined pressure range, said coherently evacuable region making up at least 20% by volume of the total volume which is occupied by a porous and/or cellular insulating material in the device, and said coherently evacuable region comprising at least one organic aerogel and/or organic xerogel.
1. A dynamically evacuable and electrically operated device, comprising:
a coherently evacuable region; and
a temperature-controllable useful region, which is thermally insulated from ambient temperature by the coherently evacuable region; and
means for actively maintaining a vacuum, such that a pressure in the coherently evacuable region of the device is constantly within a defined pressure range;
wherein:
the coherently evacuable region constitutes at least 20% by volume of a total volume which is occupied by a porous and/or cellular insulating material in the device;
the coherently evacuable region comprises an organic porous material comprising at least one of an organic aerogel and an organic xerogel;
the organic porous material is obtained by a process comprising:
reacting at least one polyfunctional isocyanate and at least one polyfunctional aromatic amine in a solvent, optionally in the presence of water and optionally in the presence of at least one catalyst; and
removing the solvent to obtain the aerogel or xerogel; and
the at least one polyfunctional aromatic amine is a compound of formula (I):
where:
each of R 1 and R 2 is independently selected from hydrogen and a linear or branched alkyl group having from 1 to 6 carbon atoms;
each of Q 1 to Q 5 and Q 1′ to Q 5′ is independently selected from hydrogen, a primary amino group, and a linear or branched alkyl group having from 1 to 12 carbon atoms;
the alkyl group may bear further functional groups provided that the compound of formula (I) contains at least two primary amino groups;
at least one of Q 1 , Q 3 and Q 5 is a primary amino group;
at least one of Q 1′ , Q 3′ and Q 5′ is a primary amino group; and
Q 2 , Q 4 , Q 2′ and Q 4′ are selected such that the compound of formula (I) contains at least one linear or branched alkyl group which may bear further functional groups and has 1 to 12 carbon atoms in an α position to at least one primary amino group bonded to the aromatic ring.
2. The device according to claim 1 , wherein the device is a refrigerating unit.
3. The device according to claim 1 , wherein the device is a refrigerator.
4. The device according to claim 1 , wherein the organic aerogel or xerogel has a volume-weighted mean pore size of 50 to 3000 nm.
5. The device according to claim 1 , wherein the organic porous material comprises an organic xerogel.
6. The device according to claim 1 , wherein the at least one polyfunctional isocyanate comprises oligomeric diphenylmethane diisocyanate and has a functionality of at least 2.4.
7. The device according to claim 1 , wherein the organic porous material is obtained by a process comprising reacting at least one polyfunctional isocyanate and at least one polyfunctional aromatic amine in a solvent in the presence of at least one catalyst.
8. The device according to claim 1 , wherein the organic porous material is obtained by a process comprising reacting at least one polyfunctional isocyanate and at least one polyfunctional aromatic amine in a solvent in the presence of water.
9. The device according to claim 1 , wherein the organic porous material is obtained by a process comprising reacting at least one polyfunctional isocyanate and at least one polyfunctional aromatic amine in a solvent in the absence of water.