A PROCESS FOR ENCAPSULATING WATER-IMMISCIBLE MATERIAL WITHIN A SHELL WALL OF POLYUREA

摘要

A process of encapsulating water-immiscible material within a shell wall of polyurea which comprises:(a) providing an aqueous phase containing an emulsifier selected from the group consisting of sodium, potassium, magnesium, calcium or ammonium salts of lignin sulfonate;(b) dispersing in a known manner, in said aqueous phase, a water-immiscible material consisting essentially of polymethylene polyphenylisocyanate dissolved in said water-immiscible material, to form a dispersion of water-immiscible phase droplets throughout the aqueous phase;(c) adding, with agitation, of said dispersion a polyfunctional amine, whereby said amine reacts with polymethylene polyphenylisocyanate to form a polyurea shell wall about said water-immiscible material;wherein said water-immiscible material is selected from the group consisting of alpha -Chloro-2''ethyl-6''-methyl-N-(1-methyl-2-methoxyethyl) acetanilide, alpha -chloro-N-(2-methoxy-6-methylphenyl) -N-(1-emthylethoxymethyl) acetamide, alpha -chloro-N-methyl-N-[2-methyl-6(3-methylbutoxy) phenyl]-acetamide, alpha-chloro-N[2-methyl-6-(2-methylpropoxy) phenyl]-N-(propoxyymethyl) acetamide, N-[(acetylamino) methyl]-alpha-chloro-N-(2, 6-diethylphenyl)-acetamide, alpha -chloro-N-methyl-N-(2-methyl-6-propoxy-phenyl)-acetamide, N-(2-butoxy-6-methylphenyl)- alpha -chloro-N-methyl-aceamide, isobutyl ester of (2, 4-dichlorophenoxy) acetic acid, 2-chloro-N-(ethoxymethyl)-6''ethyl-o-acetatoluidide, 1-(1-cyclohexen-1-yl)-3-(2-fluorophenyl)-1-methylurea, 2-chloro-N-(ethoxymethyl)-N-[2-methyl-6 trifluoromethyl)-phenyl] acetamide, alpha -chloro-N-(ethoxymethyl)-N-[2-ethyl-6-(trifluoromethyl)-phenyl] acetamide, ethyl 2-chloro-4-4(trifluloromethyl)-5-thiazolecarboxylate and benzyl 2-chloro-4-(trifluoromethyl)-5-thiazolecarboxylate and benzyl 2-chloro-4-4(trifluoromethyl)-5-thiazolecarboxylate; wherein the concentration of polymethylene polyphenylisocva- wherein the concentration of said water-immiscible material is from 480 grams to 700 grams per litre of composition and wherein the concentration of polymethylene polyphenyisocyanate is from 3.5% to 21.0% by weight of said water immiscible material, wherein the concentration of said polyfunctional amine is from 1.5% to 9% by weight of said water-immiscible material and wherein the concentration of said emulsifier is from 1/2% to 15% by weight of said water-immiscible material.