Diethylene tricarbamide and diethylene tricarbamide-formaldehyde condensation resins

Abstract

The present invention provides manufacturing of and the use of novel diethylene tricarbamide and its condensation reaction products formed by reacting with formaldehyde as wood composite binder resins and in other applications. These resins have thermosetting capabilities and therefore usefulness as binders for wood and other materials with superior resin properties of low cost, colorlessness, exceptionally good binding, and fast curing characteristics, as well as very low formaldehyde emissions. The synthesized novel starting material for the thermosetting resins of the present invention is diethylene tricarbamide.

1 . A compound of the formula with a common name of diethylene tricarbamide:
   NH 2 CONHCH 2 —CH 2 N(CONH 2 )CH 2 —CH 2 NHCONH 2      
     
     
         2 . A method of manufacturing diethylene tricarbamide comprising the steps of:
 mixing diethylenetriamine, urea, and at least one reaction medium to form a reaction mixture;   reacting said reaction mixture by heating the reaction mixture, up to 180° C. or to the boiling point of the reaction mixture, for a predetermined length of time, to generate an ammonia by-product and removing the ammonia by vaporization or by distillation with a part of the reaction mixture to form a first solution;   cooling said first solution to form precipitates which are collected as crude diethylene tricarbamide;   optionally purifying the crude diethylene tricarbamide by dissolving in water, at least one solvent, or a combination thereof, at a predetermined elevated temperature to form a second solution or slurry;   cooling said second solution or slurry to form wet crude diethylene tricarbamide crystals;   collecting the wet crude diethylene tricarbamide crystals by filtration and drying the crystals; and   optionally washing the wet crude diethylene tricarbamide crystals with a low boiling-point solvent and drying the crystals to obtain pure diethylene tricarbamide.   
     
     
         3 . The method of  claim 2 , wherein the reaction medium is at least one solvent comprising one or more of water, pyridine, formamide, dimethyl formamide, dimethyl sulfoxide, n-butanol, n-pentanol, cyclohexanol, ethylene glycol, glycerine, and mixtures thereof. 
     
     
         4 . The method of  claim 2 , wherein the solvent of the purifying step is one or more of water, pyridine, formamide, dimethyl formamide, dimethyl sulfoxide, n-butanol, n-pentanol, cyclohexanol, ethylene glycol, glycerine, any low molecular weight alcohols, and mixtures thereof. 
     
     
         5 . A method of manufacturing diethylene tricarbamide, the method comprising:
 reacting diethylenetriamine with sodium cyanate (NaOCN) at a predetermined elevated temperature in the presence of an equivalent amount of an acid (HX) and water as a solvent for a predetermined period of time to form a reaction mixture;   removing sodium salt of the acid from the reaction mixture;   cooling the reaction mixture to room temperature to form colorless precipitates and continued cooling for an effective period of time until separation of colorless precipitates from the water is completed;   collecting the separated colorless precipitates as crude diethylene tricarbamide; and   optionally purifying the crude diethylene tricarbamide by dissolving in water, in at least one solvent, or in a combination thereof, at a predetermined elevated temperature followed by cooling, filtration, and drying.   
     
     
         6 . The method of  claim 5 , wherein the solvent of the purifying step comprises one or more of water, pyridine, formamide, dimethyl formamide, dimethyl sulfoxide, n-butanol, n-pentanol, cyclohexanol, ethylene glycol, glycerine, any low molecular weight alcohols, and mixtures thereof. 
     
     
         7 . The method of  claim 5 , wherein the acid (HX) is an inorganic acid, an organic acid, or a combination thereof. 
     
     
         8 . A thermosetting resin composition comprising a 0.5%-100.0% aqueous dispersion or solids, or combination thereof, made by reacting a mixture comprising diethylene tricarbamide and formaldehyde to form a condensate, in which the molar ratio of formaldehyde to diethylene tricarbamide is from about 0.3:1 to about 4.5:1, said condensate prepared in an aqueous medium by reacting at a pH 6.0-10.0, optionally followed by reacting at a pH 5.0-6.9, or reacting only at a pH 5.0-6.9, at a temperature of at least 30° C., and having a viscosity at a resin solids concentration of 60% in water at 25° C. of from 1.0 cP or higher, and optionally adding an alkaline material to the condensate to raise the pH to a value of 6.0-11.0. 
     
     
         9 . A thermosetting resin composition comprising a 0.5%-100.0% aqueous dispersion or solids, or combination thereof, made by, firstly, reacting a mixture comprising diethylene tricarbamide and formaldehyde to form a condensate, in which the molar ratio of formaldehyde to diethylene tricarbamide is from about 0.3:1 to about 4.5:1, said condensate prepared in an aqueous medium by reacting at a pH 6.0-10.0, optionally followed by reacting at a pH 5.0-6.9, or reacting only at a pH 5.0-6.9, at a temperature of at least 30° C., and having a viscosity at a resin solids concentration of 60% in water at 25° C. of from 1.0 cP or higher, and optionally adding an alkaline material to the condensate to raise the pH to a value of 6.0-11.0 and, secondly, adding urea, melamine, diethylene tricarbamide, or a combination thereof, in a predetermined proportion to the resin condensate. 
     
     
         10 . A thermosetting resin composition comprising a 0.5%-100.0% aqueous dispersion or solids, or combination thereof, made by reacting a mixture comprising diethylene tricarbamide, a predetermined proportion of urea, melamine, or a combination thereof, and formaldehyde to form a condensate, in which the molar ratio of formaldehyde to urea, melamine, or a combination thereof, and diethylene tricarbamide is from about 0.3:1 to about 4.5:1, said condensate prepared in an aqueous medium by reacting at a pH 6.0-10.0, optionally followed by reacting at a pH 5.0-6.9, or reacting only at a pH 5.0-6.9, at a temperature of at least 30° C., and having a viscosity at a resin solids concentration of 60% in water at 25° C. of from 1.0 cP or higher, optionally adding an alkaline material to the condensate to raise the pH to a value of 6.0-11.0, and optionally adding urea, melamine, diethylene tricarbamide, or a combination thereof, in a predetermined proportion to the resin condensate. 
     
     
         11 . A thermosetting resin composition made by mixing in any proportion two or more resins of  claims 8 - 10 . 
     
     
         12 . A thermosetting resin composition comprising a cured product obtained by curing resins of  claims 8 - 11  after adding an acid material in a 0.01%-10.0% level based on the resin solids level, or optionally by adding no acid material, and by heating the resin mixture at 80° C.-300° C. until the resin mixture cures completely. 
     
     
         13 . A wood composite product made by dispersing or spreading resins of  claims 8 - 11  after adding an acid material in a 0.01%-10.0% level based on the resin solids level, or optionally by adding no acid material, wherein the composite product comprises wood elements and wherein the resin-applied wood elements are matted and hot-pressed to cure at 80° C.-300° C. until the resin cures completely. 
     
     
         14 . The wood composite product of  claim 13 , wherein the product is wood particleboard consisting of any wood species, any particle size, and any density and thickness. 
     
     
         15 . The wood composite product of  claim 13 , wherein the product is wet and dry process medium density fiber board consisting of any wood species, any fiber size, and any density and thickness. 
     
     
         16 . The wood composite product of  claim 13 , wherein the product is hardwood or softwood plywood consisting of any wood species.