Parannettu menetelmä etyleenidiamiinitetra(metyleenifosfonihapon) valmistamiseksi

摘要

The invention relates to an improved process for preparing ethylenediaminetetra(methylenephosphonic acid), in which process ethylenediamine, phosphorus acid, hydrochloric acid and formaldehyde or paraformaldehyde are reacted with each other and the reaction medium is heated to the refluxing temperature. The process is characterized in that the product is filtered from the reaction medium prior to cooling.