NEW MATERIAL: A polyisocyanate containing ester groups and having a content of aliphatically bound isocyanate groups of 18-33 wt.%, an average NCO functionality of 1 to 10 and a viscosity of 200 to 2500 mPa.s at 22°C.
USE: An isocyanate composition for a high quality two component urethane coating with a small amount of a solvent or solvent free. Having a high value of functionality and a low viscosity at the same time, average NCO functionality of at least 4.5 is desirable. The said coating composition adheres tightly to a metal substrate and useful for the preparation of light stable, thermally stable and abrasion resistant films.
PROCESS: A new polyisocyanate is obtained by reacting isocyanatecarboxyic acid chloride of formula I (R is 2-5C saturated aliphatic hydrocarbon) with a silylated sugar or sugar alcohol of formula II (R' is alkyl, aryl) at a temperature of 50-150°C and removing tri-substituted chlorosilane formed during the reaction by distillation.
YOSEFU PEDAIN
KURAUSU NAHITOKANPU
ROOZARU KAARU
MANFURETSUDO SHIYOONFUERUDERU
