PURPOSE: To obtain a polyisocyanate useful as polyurethane products, such as coatings, adhesives, elastomers and foams, with hardly any coloring by aerating an isocyanate with nitrogen gas and removing gaseous components dissolved in the isocyanate.
CONSTITUTION: An aliphatic isocyanate is decompressed or aerated with nitrogen gas under reduced pressure before carrying out and/or or during reaction to remove gaseous components, such as oxygen, carbon dioxide or hydrogen chloride, dissolved in the aliphatic isocyanate. The reaction is performed by modifying part of isocyanate groups to allophanate, biuret, carbodiimide, isocyanurate, etc. Thereby, the isocyanate is remarkably activated to advance various reactions under mild conditions, such as a low temperature, short time, small amount of the catalyst, etc.
FUKUBA TOMOAKI
HONDA MASARU
| JPS61115059A | 1986-06-02 | |||
| JPS5083356A | 1975-07-05 | |||
| JPS59108754A | 1984-06-23 |