Patent ID: 6245853
Filing Date: 2001-06-12
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 (a) urea, substituted urea or a mixture thereof, or (b) melamine, substituted melamine or a mixture thereof, to the reaction mixture; andheating the reaction mixture to a temperature at which condensation takes place between (a) the urea, substituted urea or mixture thereof, or (b) the melamine, substituted melamine or mixture thereof, and the formaldehyde, to form a urea formaldehyde or melamine 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 or melamine formaldehyde resin; andcooling the reaction mixture.