| 摘要 |
1503542 Polyethylene foam/polyurethane composites BAYER AG 1 May 1975 [24 July 1974 6 May 1974] 18196/75 Heading B2E A composite material comprises a layer of cross-linked polyethylene foam joined in the absence of an adhesion promotor to a layer of unfoamed polyurethane. Several alternate layers of each material may be present. The polyethylene foam is preferably crosslinked by electron beam, Co90 rays, or by peroxides. An exhaustive list of suitable polyurethanes is given. The polyurethane may be applied as a dispersion, solution, suspension or powder and heated, or by applying a mixture of isocyanate/reactive hydrogen precursors e.g. as a melt and allowing them to harden. Powder coatings may be calendered after being heated. In Examples: (1 to 3) polyurethane powders are applied to the surface of polyethylene foams which have a closed-cell surface or open-cell surface formed by slicing off the closed-cell surface; (4, 6) a reaction mixture is sprayed onto polyethylene foam surfaces; and (5) a hot reaction mixture is poured onto polyethylene foam. |
