Microencapsulation process
AssigneeChampion International Corporation
InventorAnthony E. Vassiliades
Life of this patent
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Abstract
Microcapsules are formed in the absence of coacervation by providing an oil-in-water emulsion containing a polymeric, emulsifying agent having cross-linkable groups or complexing sites and admixing with the emulsion a cross-linking agent or a complexing agent which forms an impermeable coating around the dispersed oil droplets. The emulsifying agent may be non-proteinaceous or the protein, gelatin. Impermeable capsule walls are formed solely by the addition of the cross-linking or complexing agent and extraneous hardening agents are obviated. Moreover, the emulsifying agent may be a preformed, polymeric, cross-linking agent which eliminates the need for any separate cross-linking agent.
Claims6
A process for the formation of microcapsules having non-proteinaceous walls, in the absence of coacervation, which comprises the steps of:
- (A) forming a primary oil-in-water emulsion, which emulsion comprises a water-immiscible oily material dispersed in the form of microscopic droplets in a colloidal solution of a non-proteinaceous, polymeric emulsifying agent having about the same hydrophil-lipophil balance as the oily material, said emulsifying agent being selected from the group consisting of an emulsifying agent possessing cross-linkable groups and an emulsifying agent possessing complexing sites;
- and
- (B) forming an impermeable coating around said dispersed oil droplets solely by adding to the aqueous phase of said emulsion a member different from said emulsifying agent and selected from the group consisting of gum tragacanth and a borate under conditions of brisk agitation, said member reacting with said non-proteinaceous emulsifying agent so as to form a non-proteinaceous impermeable coating around said dispersed oil droplets.
Dependencies are inferred from the claim text.