Daicel Chemical Industries, Ltd.

Toyokazu Yagii

Kiyokazu Murata

Teruo Itokazu

Hidetaka Kojima

Yasutaka Tanaka

Kenji Oka

Shoji Watanabe

Takaaki Murai

Kimio Inoue

Toshihide Maruyama

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.

Process for preparation of isocyanate compounds

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.

Process for preparation of aliphatic diisocyanate compounds

A diisocyanate compound substantially free from chlorine is prepared by the following consecutive steps (1), (2) and (3):

Process for producing polyurethane

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, and

Growing community of inventors

Hiroshima, Japan

Toyokazu Yagii