Process of making urea-formaldehyde solid microspheres

Claim 1

PREPARATION OF SPHEROIDAL SOLID SHAPED MICROSPHERES OF UREA-FORMALDEHYDE, SAID MICROSPHERES HAVING A SURFACE AREA OF FROM 10 TO 90 M2/GM, AND HAVING A DIAMETER RANGE FROM 0.2 U TO 4.0 U, WHICH COMPRISES ADMIXING WITH HIGH SHEAR AT A STEMPERATURE FROM 15*C. TO 40*C. AN AQUEOUS SOLUTION OF UREAFORMALDEHYDE PREPOLYMER AND A NON-SOLVENT CONTAINING AN EMULSIFYING AGENT TO FORM WATER DROPLETS IN A WATER-IN OIL EMULSION, SAID EMULSIFYING AGENT SELECTED FROM THE GROUP CONSISTING OF THE POLYMER OF ETHYL ACRYLATE GRAFTED ONTO POLYETHYLENE OXIDE AND THE SORBITOL ESTER OF LONG CHAIN FATTY ACIDS HAVING AN HLB BETWEEN 4.3 AND 8.6, SAID UREA-FORMALDEHYDE PREPOLYMER DISSOLVED IN THE WATER DROPLETS, ADDING AN ACID CATALYST TO THE EMULSION TO ADJUST THE PH TO FALL WITHIN THE RANGE OF FROM 2 TO 5 DURING WHICH TIME THE PREPOLYMER DISSOLVED IN THE WATER DROPLETS POLYMERIZES AND FORMS SPHERICAL SHAPED PARTICLES OF UREA-FORMALDEHYDE, AGAIN THE SUSPENSION FOR AT LEAST ONE HOUR, DILUTING THE SUSPENSION WITH WATER, ADDING A DISPERSING AGENT, SAID DISPERSING AGENT SELECTED FROM THE GROUP CONSISTING OF PIGMENT DISPERSING AGENTS, POTASSIUM TRIPOLYPHOSPHATE, SODIUM HEXAMETAPHOSPHATE AND SODIUM LAURYL SULFATE, AND THEN THE NEUTRALIZING THE DILUTED DISPERSED SLURRY TO PH OF 6.5 - 7.5, SEPARATING THE SPHERICAL PARTICLES FROM THE SOLVENT AND NON-SOLVENT AND DRYING THE PARTICLES.