| 摘要 |
A low-catalyst-content isocyanate mixture containing at least one of a carbodiimide group and a uretonimine groups, obtained by: reacting at least one monomeric diisocyanate (A) in the presence of phosphorus-containing catalyst (B), to obtain a reaction mixture comprising carbodiimide, where the reaction does not take place to complete conversion of the diisocyanate (A) and 1-80% by weight of the diisocyanate (A) employed remains in the reaction mixture as excess diisocyanate; and subsequently simultaneously removing, by distillation, a fraction of the excess of diisocyanate and the catalyst (B), to obtain the isocyanate mixture and a distillate, where the isocyanate mixture has a monomeric diisocyanate (A) content of 0.5%-20% by weight, based on the monomeric diisocyanate (A) employed, and a catalyst (B) content of 0% to 20% by weight, based on the catalyst (B) employed. In addition, a process for preparing a low-catalyst-content isocyanate mixture.
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