Preparation of guanidine phosphate for hardboard flame retardant use

摘要

A guanidine phosphate composition containing both monoquanidine phosphate and diguanidine phosphate and characterized by a weight loss of less than 1% when heated for one hour at 220 DEG C. is prepared by mixing together about equimolar quantities of phosphoric acid and cyanoguanidine and heating this reaction mixture with agitation in the presence of a surfactant to a temperature in the range of 200 DEG C. to 240 DEG C. Agitation is continued for two hours at 200 DEG C. or until foaming stops (about one hour at 240 DEG C.). The guanidine phosphate composition so obtained may be applied to cellulosic materials to render them fire retardant.