Patent ID: 7914880

Claim:
A composite structure comprising the following layered structure: (i) from 2 to 20 mm of metal, (ii) from 10 to 100 mm of a polyisocyanate polyaddition product having a density of from 350 to 1050 kg/m 3 comprising the reaction product of (a) an isocyanate and (b) an isocyanate-reactive compound in the presence of (f) an expanding agent present in an amount of from 0.05 to 10 parts by weight based on the weight of said polyisocyanate polyaddition product, and (iii) from 2 to 20 mm of metal; wherein said (ii) polyisocyanate polyaddition product is disposed between said (i) and (iii) and in contact with at least one of said (i) and (iii); and wherein surfaces of at least one of said (i) and (iii), which are in contact with said (ii), are free from inorganic and/or organic substances other than said (ii).