Preparation method for low-color number, low-odor polyisocyanate curing agent

Abstract

Disclosed is a preparation method for a low-color number, low-odor polyisocyanate curing agent. The preparation method comprises a step of carrying out a polymerization reaction on a diisocyanate monomer under the action of a trimerization catalyst in a polymerization reaction kettle with continuously flowing inert gas, an upper head of the polymerization reaction kettle being provided with an inert gas inlet pipe, the inert gas inlet pipe being an insertion pipe, and the upper head of the polymerization reaction kettle also being provided with an inert gas outlet and a central stirring shaft; the insertion opening position (A) of the inert gas inlet pipe and the inert gas outlet position (B) on the surface of the upper head form an angle α (∠ACB) with the fixed position (C) of the central stirring shaft projected onto the plane on the upper head surface, where 30°≤α≤180°. The present application can achieve stable catalytic activity of a catalyst by means of controlling the use of nitrogen during the reaction process, which is conducive to stable process control, resulting in a low color number and reduced amine odor in the obtained product.

Dependencies are inferred from the claim text.