Herein disclosed are an .alpha.-(aminocyclohexyl)alkylamine represented by the following general formula (II): ##STR1## wherein R represents hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, provided that the amino group bonded to the cyclohexyl group may be in either of the 2-, 3- and 4-positions and a method for preparing it; an .alpha.-(isocyanatocyclohexyl)alkylisocyanate of Formula (II) wherein the amino groups are replaced with isocyanato groups and a method for preparing it; polyisocyanato-isocyanurate represented by the following general formula (IV): ##STR2## wherein R.sub.1, R.sub.2 and R.sub.3 may be the same or different and each represents a group represented by the following general formula: ##STR3## wherein R represents hydrogen atom or an alkyl group having 1 to 5 carbon atoms and n is an integer ranging from 1 to 5 and a method for preparing it; and a resin obtained by polymerizing an organic polyisocyanate containing not lower than 10% by weight of the polyisocyanato-isocyanurate represented by Formula (IV) and a compound having at least two active hydrogen atoms as well as a resin composition for coating materials which comprises the resin.