atoms and especially the methyl or ethyl radicals y in the silane crosslinking polymer of component a may represent a residue of any polymer where at least 50 preferably at least 70 and more preferably at least 90 of all bonds in the main chain are carbon carbon carbon nitrogen or carbon oxygen bonds examples of y polymer residues are polyester polyether polyurethane polyalkylene and polyacrylate residues the polymer residue y is preferably an organic polymer residue where the polymer chain comprises polyoxyalkylenes such as polyoxyethylene polyoxypropylene polyoxybutylene polyoxytetramethylene polyoxyethylene polyoxypropylene copolymer and polyoxypropylene polyoxybutylene copolymer the cr 1 2 b u2014 sir a or 2 3 a group or groups is preferably linked via u2014 o u2014 c u2550 o u2014 nh u2014 u2014 nh u2014 c u2550 o o u2014 u2014 nh u2014 c u2550 o u2014 nh u2014 u2014 nr u2032 u2014 c u2550 o u2014 nh u2014 nh u2014 c u2550 o u2014 nr u2032 u2014 u2014 nh u2014 c u2550 o u2014 u2014 c u2550 o u2014 nh u2014 u2014 c u2550 o u2014 o u2014 u2014 o u2014 c u2550 o u2014 u2014 o u2014 c u2550 o u2014 o u2014 u2014 s u2014 c.