Abstract: An aliphatic diisocyanate compound is prepared in a high yield by reacting dimethyl carbonate with an aliphatic diamine in the presence of an alkali catalyst to produce a corresponding urethane compound; and, within 48 hours after the completion of the preparation of the urethane compound, thermally decomposing the urethane compound under a reduced pressure of 1 to 700 Torr in a high-boiling-point solvent.

Abstract: An aliphatic diisocyante compound is prepared in a high yield by reacting dimethyl carbonate with an aliphatic diamine in the presence of an alkali catalyst to produce a corresponding urethene compound; and, within 48 hours after the completion of the preparation of the urethane compound, thermally decomposing the urethane compound under a reduced pressure of 1 to 700 Torr in a high-boiling-point solvent.

Abstract: A diisocyanate compound substantially free from chlorine is prepared by the following consecutive steps (1), (2) and (3):(1) preparing dimethyl carbonate by a method selected from:(a) a method wherein carbon monoxide and oxygen are reacted with methanol,(b) a method wherein propylene oxide is reacted with carbon dioxide to prepare propylene carbonate, and then, the propylene carbonate is reacted with methanol, and(c) a method wherein a nitrous acid ester is catalytically reacted with carbon monoxide;(2) reacting the dimethyl carbonate with an aliphatic diamine in the presence of an alkali catalyst to prepare a corresponding urethane compound; and(3) thermally decomposing the urethane compound under a reduced pressure of 1 to 700 Torr in a high-boiling point solvent.

Abstract: A process for producing polyurethane useful as coating material, which comprises preparing dialkyl carbonate, substantially without using phosgene, reacting the carbonate with a diamine to give a urethane, thermally decomposing the urethane into a diisocyanate, and converting the diisocyanate into a polyurethane in the presence of a Lewis acid and/or a protonic acid. The reaction of a diisocyanate compound containing a reduced amount of chlorine is promoted by a Lewis acid and/or a protonic acid.

Abstract: A polyether compound having ether groups and vinyl double bonds represented by formula (I) ##STR1## wherein R.sub.1 represents a residue of an organic compound having l active hydrogen atoms, n.sub.1 through n.sub.l each represents 0 or an integer of from 1 to 100, the sum of the integers represented by n.sub.1 through n.sub.l is from 1 to 100, andl represents an integer of from 1 to 100, and A represents ##STR2## and a process for production thereof; an epoxy resin represented by formula (II) ##STR3## wherein R.sub.1 and n.sub.1 through n.sub.l are defined above, and B is an oxycyclohexane unit having a substituent and is represented by formula (III) ##STR4## wherein X represents a ##STR5## --CH.dbd.CH.sub.2, or ##STR6## groups, wherein R.sub.