Microcapsule Clusters

Abstract

The present invention teaches a composition and process for irreversibly agglomerated charge stable core shell microcapsules, each microcapsule containing a benefit agent core material, which may be the same or different, the polymeric all or walls comprising one or more (meth)acrylate polymers, or optionally combinations with other polymers, along with a polyvalent cation. The capsules of the invention adhere better to surfaces, are more stable and are useful for delivery of benefit agents.

1 - 13 . (canceled) 
     
     
         14 . A process for preparing a cluster of microcapsules encapsulating an oil phase, the cluster being substantially irreversibly agglomerated, the process comprising:
 dispersing an oil soluble amine modified polyfunctional polyvinyl monomer or oligomer and an oil soluble bi- or polyfunctional vinyl monomer or oligomer along with a free radical initiator and an organic acid and a core material into an internal phase oil;   a first heating step comprising, heating for a time and temperature sufficient to pre-polymerize the amine modified polyfunctional polyvinyl monomer or oligomer and oil soluble bi- or polyfunctional vinyl monomer or oligomer;   adding to the internal phase oil a water phase in excess comprising a dispersion in water of a polyacrylic or poly(meth)acrylic acid, a free radical initiator, and an emulsifying agent;   emulsifying the oil phase into the water phase forming an emulsion of droplets of the oil phase dispersed in the water phase;   heating the emulsion for a time and temperature sufficient to decompose the free radical initiator in the oil and water phases thereby forming microcapsule wall material at the interface of the water and oil phases, the microcapsules encapsulating the oil phase droplets;   adding a polyvalent cation to the emulsion; and,   further heating for a time sufficient to polymerize the wall material and agglomerate the wall material, the polyvalent cation being incorporated into the microcapsule wall, thereby forming the cluster of microcapsules.   
     
     
         15 . The process according to  claim 14  comprising adding the polyvalent cation after the emulsifying step. 
     
     
         16 . The process according to  claim 14  comprising adding a polyvalent cation selected from the group consisting of Al(III), Zr(IV) and Fe(III). 
     
     
         17 . The process according to  claim 14  wherein in the emulsifying step the droplets of the oil phase are comminuted to a particle size of from 0.1 to 150 microns. 
     
     
         18 . The process according to  claim 14  wherein the cluster of microcapsules formed has a zeta potential form -60 millivolts to +60 millivolts. 
     
     
         19 . The process according to  claim 14  wherein the cluster of microcapsules formed is cationic.