78149-92-5Relevant articles and documents
Preparation method of 1, 5-pentamethylene diisocyanate
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Paragraph 0055-0058; 0063-0066; 0071-0074; 0079-0082;......., (2022/03/18)
The invention provides a preparation method of 1, 5-pentamethylene diisocyanate, which comprises the following steps: (1) mixing 1, 5-pentamethylene diamine, a carbonylation agent, a first solvent and a catalyst, carrying out carbonylation reaction, and carrying out solid-liquid separation to obtain a 1, 5-pentamethylene dicarbamate reaction solution; and (2) carrying out purification treatment on the 1, 5-pentamethylene dicarbamate reaction solution obtained in the step (1), mixing the purified 1, 5-pentamethylene dicarbamate with a second solvent, and carrying out pyrolytic reaction to obtain the 1, 5-pentamethylene diisocyanate. The preparation method has the advantages of mild reaction conditions, simple operation, no pollution, small potential safety hazard, and high yield and purity of the intermediate product PDC and the final product PDI.