Vacuum insulation panel

1. A vacuum insulation panel comprising:

(a) a porous insulating core having an upper surface and a lower surface and sides;

(b) an envelope about the core arranged to envelop the core, and to maintain an applied vacuum within the envelope; and

(c) a non-foam polyurethane coating layer applied to the envelope, wherein the coating layer is formed over the entire surface area of the envelope, the polyurethane coating layer is less than about 5 mm thick and

(d) the envelope and the polyurethane coating layer form a barrier layer about the insulating core, the barrier layer having a moisture vapour transmission rate of from about 1.5×10 −3 g/m 2 ·day to about 3.0×10 −3 g/m 2 ·day when measured in accordance with ASTM F1249-90.

2. The vacuum insulation panel according to claim 1 , wherein the envelope comprises a metallised film.

3. The vacuum insulation panel according to claim 1 , wherein the polyurethane coating layer is from about 0.1 mm to about 3 mm thick.

4. The vacuum insulation panel according to claim 1 , wherein the polyurethane coating layer has a vapour resistivity of from 5000 MN·s/gm to 100000 MN·s/gm or more.

5. The vacuum insulation panel according to claim 1 , wherein the polyurethane coating layer is formed from a polyurethane resin composition comprising a first isocyanate containing part and a second polyol containing part.

6. The vacuum insulation panel according to claim 1 , wherein the barrier layer has a moisture vapour transmission rate of about 2.5×10 −3 g/m 2 ·day or less, when measured in accordance with ASTM F1249-90.

7. The vacuum insulation panel according to claim 1 , wherein the barrier layer having an oxygen transmission rate of from about 2×10 −3 cc/m 2 ·day to about 5×10 −3 cc/m 2 ·day when measured in accordance with ASTM D3985.

8. The vacuum insulation panel according to claim 1 , wherein the barrier layer having a moisture vapour transmission rate of about 2.5×10 −3 g/m 2 ·day or less, and an oxygen transmission rate of about 4×10 −3 cc/m 2 ·day or less.

9. The vacuum insulation panel according to claim 1 , wherein the porous insulating core is constructed from a microporous powder material selected from silica, fumed silica and/or precipitated silica, perlite, diatomaceous earth and combinations thereof.

10. The vacuum insulation panel according to claim 1 , having a thermal conductivity of from 3.0 mW/(m·K) to 4.5 mW/(m·K).

11. The vacuum insulation panel according to claim 1 , further comprising at least one reinforcing member arranged on the upper or lower surface of the insulating core to reinforce the core, wherein the reinforcing member is formed of a porous material, and is substantially rigid; wherein together the at least one reinforcing member and the insulating core form a hybrid core and the reinforcing member(s) do not form a thermal bridge across the insulating core; and wherein the envelope is arranged to envelop the hybrid core.

12. The vacuum insulation panel according to claim 11 having an upper reinforcing member arranged on the upper surface of the insulating core and having a lower reinforcing member arranged on the lower surface of the insulating core.

13. The vacuum insulation panel according to claim 11 wherein the at least one reinforcing member comprises a metal foil facer, the metal foil facer having a thickness of from 4 microns to 50 microns, and extending across substantially the entire surface of the reinforcing member, on the upper surface or lower surface thereof and wherein the metal foil facer does not form a thermal bridge between the upper surface and lower surface of the reinforcing member.

14. The vacuum insulation panel according to claim 11 , wherein the density of the insulating core within the vacuum insulating panel is of from 100 kg/m 3 to 160 kg/m 3 .

15. The vacuum insulation panel according to claim 11 , wherein the at least one reinforcing member(s) has a density that is lower than that of the insulating core.

16. The vacuum insulation panel according to claim 11 , further comprising at least one metal foil having a thickness of from 4 microns to 50 microns, between the envelope and the insulating core and extending across substantially the entire surface of the insulating core on the upper surface or lower surface thereof and wherein the foil does not form a thermal bridge between the upper surface and lower surface of the insulating core.

17. The vacuum insulation panel according to claim 16 , wherein the metal foil is attached to the inside of the envelope.

18. The vacuum insulation panel according to claim 17 , wherein the envelope comprises an envelope inner layer and the metal foil has at least one outer layer attached thereto wherein the envelope inner layer and the outer layer on the metal foil are attached to each other being optionally bonded to each other.

19. The vacuum insulation panel according to claim 16 , comprising two metal foils having a thickness of from 4 micron to 50 micron, wherein one metal foil extends across substantially the entire surface of the core on the upper surface and a second metal foil extends across substantially the entire surface of the core on the lower surface.

20. The vacuum insulation panel according to claim 1 , further comprising a layer of adhesive on the outer surface of the panel.

21. The vacuum insulation panel according to claim 20 , wherein the adhesive is a pressure sensitive adhesive.