Process For Producing Microcapsules
AssigneeCognis IP Management GmbH
InventorsWolfgang Denuell, Jutta Hotz
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Abstract
The application describes a process for producing microcapsules which contain a shell made of polyurea and which surround in their interior a water-insoluble oil, where the shell is obtained by the reaction of two structurally different diisocyanates in emulsion form.
Claims18
A process for producing microcapsules which contain a shell and a core of a liquid, water-insoluble material, the process comprising:
- bringing together an aqueous solution of a protective colloid and a solution of a mixture of at least two structurally different at least difunctional diisocyanates (A) and (B) in a water-insoluble liquid until an emulsion is formed;
- adding an at least difunctional amine to the emulsion;
- and
- heating to a temperature of at least 60° C. until the microcapsules are formed,
- wherein the isocyanate (B) is selected from the anionically modified isocyanates or the polyethylene oxide-containing isocyanates and the isocyanate (A) is uncharged and is not a polyethylene oxide-containing isocyanate.
A perfume-free microcapsule comprising a liquid core of a water-insoluble liquid, and a shell of a reaction product of at least two different at least difunctional isocyanates (A) and (B), where the isocyanate (B) comprises an anionically modified isocyanate or a polyethylene oxide-containing isocyanate or mixtures of these types, and an at least one difunctional amine, with the proviso that during production of the microcapsules, the weight ratio between the isocyanates (A) and (B) is in the range of from 10:1 to 1:10.
Dependencies are inferred from the claim text.