Hexanedioic acid, polymer with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol, 1,6-hexanediol, 3-hydroxy-2-(hydroxymethyl)propanoic acid and 5-isocyanato-1-(isocyanatomethyl) -1,3,3-trimethylcyclohexane, caprolactam-blocked, compd. with 2-(dimethylamino)ethano