Polyurea capsules prepared with a polyisocyanate and cross-linking agent

Abstract

Polyurea capsules that encapsulate active materials in polymeric walls resulting from the polymerization of an aromatic or aliphatic polyisocyanate and a cross-linking agent are provided as are consumer products containing said polyurea capsules and for methods for producing such capsules.

What is claimed is: 
     
         1 . A method for preparing a polyurea capsule composition comprising:
 (a) preparing an oil phase comprising an active material and a polyisocyanate;   (b) preparing a surfactant solution;   (c) emulsifying the oil phase into the surfactant solution to form a fragrance emulsion;   (d) adding a cross-linking agent to the fragrance emulsion to form a capsule slurry; and   (e) curing the capsule slurry,   wherein the active material is a fragrance oil present at a level of about 5% to about 80% of the capsule composition; the polyisocyanate, added at a level of about 0.1% to about 10% by weight of the capsule composition, consists of a trimethylol propane-adduct of xylylene diisocyanate; the surfactant is added at a level of about 0.1% to about 5% by weight of the capsule composition; the cross-linking agent, added at a level of about 0.1% to about 5% by weight of capsule composition, is gelatin; an encapsulating polymer is formed by the polymerization reaction between the polyisocyanate and the cross-linking agent; and the encapsulating polymer encapsulates the active material.   
     
     
         2 . The method of  claim 1 , wherein the surfactant is polyvinyl alcohol, polystyrene sulfonate, carboxymethyl cellulose, sodium salt of naphthalene sulfonate condensate, or a mixture thereof. 
     
     
         3 . The method of  claim 1 , further comprising
 (f) adding a salt to the cured capsule slurry; and   (g) washing the cured capsule slurry with water.   
     
     
         4 . A polyurea capsule composition prepared by the method of  claim 1 . 
     
     
         5 . The polyurea capsule composition of  claim 4 , wherein the polyurea capsule composition further comprises a deposition aid. 
     
     
         6 . The polyurea capsule composition of  claim 5 , wherein the deposition aid is an anionic, cationic, nonionic or zwitterionic polymer. 
     
     
         7 . A consumer product comprising the polyurea capsule composition of  claim 4 . 
     
     
         8 . The consumer product of  claim 7 , wherein the consumer product is a shampoo, a hair conditioner, a soap, a body wash or other hygiene product, a cosmetic preparation, a body liquid detergent, an all-purpose cleaner, a fabric softener or refresher, an ironing water or a detergent, softener or drier sheet.