PURPOSE: To obtain a new diisocyanate useful for producing a plastic containing urethane group or urea group and having a photostability and a weather resistance.
CONSTITUTION: This new diisocyanate is a diisocyanate of formula I (R is H or a 1-4C aliphatic hydrocarbon; R1 is a 1-12C aliphatic or a cycloaliphatic hydrocarbon). The compound of formula I is obtained by phosgenating a diamine corresponding to formula II. A modified isocyanate containing an allophanate group, biuret group, isocyanulate group, urethane group or biuretodione group is obtained by using the diisocyanate of formula I as a base material. Further, the diamine for producing the diisocyanate is obtained e.g. by reacting a nitrile of formula III with a malonic acid ester corresponding to formula IV to obtain a dinitrile of formula V, and hydrogenating the dinitrile. The diisocyanate of formula I is a liquid having a low viscosity and a high boiling point or a solid having a low melting point. From the diisocyanate, a plastic is obtained by a poly-addition method of the isocyanide.
KURAUSU YOOSUTO
SHIYUTEFUAN PENINGERU
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