US 12,220,677 B2
Process for the preparation of microcapsules
Julian Alexander Georgi, Holzminden (DE); Benjamin Rost, Bodenwerder (DE); Diane Dröge, Bodenwerder (DE); Ralf Bertram, Holzminden (DE); and Thorsten Böddeker, Brakel (DE)
Assigned to SYMRISE AG, Holzminden (DE)
Appl. No. 17/430,943
Filed by SYMRISE AG, Holzminden (DE)
PCT Filed Feb. 13, 2019, PCT No. PCT/EP2019/053600
§ 371(c)(1), (2) Date Aug. 13, 2021,
PCT Pub. No. WO2020/164705, PCT Pub. Date Aug. 20, 2020.
Prior Publication US 2022/0105486 A1, Apr. 7, 2022
Int. Cl. B01J 13/14 (2006.01); A61K 9/50 (2006.01); B01J 13/20 (2006.01); C11D 3/00 (2006.01); C11D 3/50 (2006.01)
CPC B01J 13/14 (2013.01) [A61K 9/5031 (2013.01); A61K 9/5089 (2013.01); B01J 13/206 (2013.01); C11D 3/001 (2013.01); C11D 3/505 (2013.01); C11D 2111/12 (2024.01)] 20 Claims
 
1. A process for preparing isocyanate-based microcapsules comprising:
(a) providing an internal non-aqueous phase comprising at least one isocyanate having two or more isocyanate groups or at least one isothiocyanate having two or more isothiocyanate groups and a hydrophobic agent to be encapsulated;
(b) providing an external aqueous phase comprising at least one protective colloid and a catalyst;
(c) mixing the internal non-aqueous phase and the external aqueous phase, optionally in the presence of a stabilizer and/or an emulsifier, to obtain an oil-in-water emulsion;
(d) a first crosslinking by addition to the composition of step (c) of an amine reacting at an acidic pH;
(e) further crosslinking by addition to the composition of step (d) of an amine reacting at an alkaline pH to obtain microcapsules;
(f) curing the microcapsules obtained in step (e); and
optionally:
(g) separating the microcapsules from the reaction solution and further optionally drying of the microcapsules.