Propanoic acid, 3-hydroxy-2-(hydroxymethyl)-2-methyl-, polymer with 1,4-butanediol, dimethyl carbonate, 1,6-hexanediol, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane, 1,1'-methylenebis[4-isocyanatocyclohexane] and 2-oxepanone, diethanolamine- and 2-ethyl-1-hexanol-blocked, compds. with triethylamine