| abstract |
The invention relates to composite elements which have the following layer structure: (i) 2 to 20 mm of metal, plastic or wood, (ii) 10 to 300 mm polyisocyanate polyaddition products, (iii) 2 to 20 mm of metal, plastic or wood, wherein the layer (ii) contains preformed polyisocyanate polyaddition products (x) adhered to the layers (i) and (iii) by polyisocyanate polyaddition products (xx), and the polyisocyanate polyaddition products (x) are pieces with a volume between 4 cm 3 and 1000 cm 3 is. |