Patent ID: 6528582
Filing Date: 2003-03-04
Classification: C08G,C08J

Abstract:
A one-step, in-situ, process for producing a high solids content emulsion or dispersion of partially or totally crosslinked aminoplast resin droplets or particles, comprising:forming a reaction mixture containing (i) aqueous formaldehyde(formalin), (ii) at least one water-soluble protective colloid, (iii) water and (iv) optionally a surfactant, and mixing the reaction mixture in a reaction vessel; optionally adjusting the initial pH of the reaction mixture to a desired value; adding (i) urea or substituted urea, (ii) melamine or substituted melamine, or (iii) a mixture thereof, to the reaction mixture; and heating the reaction mixture to a temperature at which condensation takes place between the (i) urea or substituted urea, (ii) melamine or substituted melamine, or (iii) the mixture thereof, and the formaldehyde, to form a urea formaldehyde resin, a melamine formaldehyde resin or a melamine urea formaldehyde resin, and then holding the reaction mixture at said temperature or a higher temperature, under mixing, for a period of time sufficient to achieve a desired degree of crosslinking in said urea formaldehyde resin, melamine formaldehyde resin or melamine urea formaldehyde resin; and cooling the reaction mixture.