Fire retardant

Abstract

Improved fire retardants that include guanylurea phosphate [(H 2 N—C(NH)—NH—C(O)—NH 2 ).H 3 PO 4 ] (GUP) and boric acid, materials such as wood and composite wood products that include these fire retardants, and methods of making and using same.

What is claimed is:  
     
         1 ) An improved GUP/boric acid formulation that has greater than 95 percent purity.  
     
     
         2 ) An improved GUP/boric acid formulation that has less than one percent of the salt of dicyandiamide and phosphoric acid.  
     
     
         3 ) An improved solid GUP/boric acid formulation that has an even dispersion of GUP and boric acid.  
     
     
         4 ) An improved solid GUP/boric acid formulation that has a solubility of at least 70% in water.  
     
     
         5 ) The composition of  claim 1  wherein the amount of unreacted starting materials and unwanted by-products from the GUP reaction process are less than 2 wt. % of the theoretical GUP yield.  
     
     
         6 ) The composition of  claim 1  wherein the amount of unreacted starting materials and unwanted by-products from the GUP reaction process are less than 1 wt. % of the theoretical GUP yield.  
     
     
         7 ) The composition of  claim 1 , wherein the composition does not exhibit an equivalence point at a pKa of about 3.2.  
     
     
         8 ) The composition of  claim 1 , in the substantial absence of a dicyandiamide/phosphoric acid salt.  
     
     
         9 ) The composition of  claim 1  in the form of a solid, wherein the GUP and boric acid are substantially evenly dispersed throughout the composition.  
     
     
         10 ) The composition of  claim 1  in the form of solid particulates, wherein the GUP and boric acid are substantially evenly dispersed throughout the composition.  
     
     
         11 ) The composition of  claim 1  in the form of solid flowable particulates.  
     
     
         12 ) The composition of  claim 1  in the form of solid spherical particulates.  
     
     
         13 ) The composition of  claim 1  in the form of solid particulates having a substantially narrow size distribution.  
     
     
         14 ) The composition of  claim 1  in the form of solid particulates having an average diameter of less than 50 microns.  
     
     
         15 ) The composition of  claim 1  in the form of solid particulates substantially in the absence of fines.  
     
     
         16 ) The composition of  claim 3  in the form of a solid fire retardant composition.  
     
     
         17 ) A fire retardant composition in the form of solid flowable particulates.  
     
     
         18 ) The fire retardant composition of  claim 17  in the form of solid spherical particulates.  
     
     
         19 ) The fire retardant composition of  claim 17  in the form of solid particulates having a substantially narrow size distribution.  
     
     
         20 ) The fire retardant composition of  claim 17  in the form of solid particulates having an average diameter of less than 50 microns.  
     
     
         21 ) The composition of  claim 17 , wherein the fire retardant is selected from a GUP and boric acid composition, ammonium phosphates, ammonium polyphosphates, guanidine phosphate, melamine phosphate, phosphoric acid, dicyandiamide, ammonium sulfate, borax (sodium tetraborate), disodium octaborate, urea, and formaldehyde.  
     
     
         22 ) The composition of  claim 2  that does not exhibit an equivalence point at a pKa of about 3.2.  
     
     
         23 ) The composition of  claim 4  in the form of a liquid that comprises greater than 70 wt. % solids.  
     
     
         24 ) A method of producing GUP/boric acid fire retardants comprising reacting dicyandiamide and phosphoric acid under conditions that yield linear reaction kinetics.  
     
     
         25 ) The method of  claim 24  comprising dissolving in water, substantially simultaneously, dicyandiamide, phosphoric acid, and boric acid, and reacting at least a portion of the dicyandiamide and the phosphoric acid to form guanylurea phosphate.  
     
     
         26 ) The method of  claim 24  performed under conditions that inhibit the evolution of heat from the reaction.  
     
     
         27 ) The method of  claim 24  comprising: 
 a) providing an aqueous bath,  
 b) adding phosphoric acid to the bath,  
 c) adding dicyandiamide to the bath,  
 d) adding boric acid to the bath, and  
 e) heating the bath, or allowing it to heat, to a temperature that does not yield a substantial exotherm,  
 f) wherein: steps (a)-(d) are performed simultaneously, consecutively, or in any order.  
 
     
     
         28 ) A method of producing GUP/boric acid solids comprising dewatering an aqueous solution that comprises GUP and boric acid.  
     
     
         29 ) The method of  claim 28  wherein the dewatering is effected via spray drying.  
     
     
         30 ) A method of treating cellulosic materials for fire retardance comprising contacting the cellulosic material with the fire retardant composition of  claim 1 .  
     
     
         31 ) The composition of  claim 1  further comprising a cellulosic material.  
     
     
         32 ) The composition of  claim 31  in the form of a composite wood product.  
     
     
         33 ) The composition of  claim 31  in the form of composite wood furnish.