High-temperature damping composite

Claim 1

A composite at least 1/2 meter in both width and length of a structural metal sheet and a viscoelastic layer, which composite can be formed to provide components of or facings for machines in order to provide effective damping of vibrations in such machines during prolonged high-temperature operation, said metal sheet having an average plastic strain ratio r of at least 1.3, a strain-hardening exponent n of at least 0.11 in the equation σ=Kε.sup.n where σ is the true stress, K is a constant and ε is the true strain, and a thickness of at least 0.2 mm, and said viscoelastic layer having a thickness of at least 20 micrometers and being a cured polycyanurate polymer comprising the repeating unit ##STR7## wherein each R is the residue after removal of the hydroxyl radicals from one of (a) HO--Ar--OH (b) ##STR8## (c) HOCH 2 --(CH 2 CH 2 ) j (CF 2 CFX) k ] m CH 2 OH (d) HO--CH 2 CF 2 (CF 2 ) h CF 2 CH 2 OH wherein h is 0 or an integer of 1 to 6, j and k are integers whose ratio j/k is 1/1 to 10/1, m is an integer of 1 to 100, n is an integer of 1 to 20, X is fluorine or perfluoroalkyl, --Ar--represents ##STR9## wherein Z represents --S--, --SO 2 --, --O--, ##STR10## wherein R 1 and R 2 represent hydrogen, lower alkyl or ##STR11## wherein ω is an integer from 2 to 6, ##STR12## and the polycyanurate polymer has sufficient crosslinks such that its cyanurate nitrogen comprises 0.5 to 2% of its total weight when the polymer comprises 60% fluorine and 1.0 to 3.5% of its total weight when it is free from fluorine.