US 12,661,627 B2Granted

Biodegradable polyurea/polyurethane microcapsules

AssigneeSymrise AG

InventorsJulian Alexander Georgi, Britta Raabe, Benjamin Rost, Andreas Vogel, Ralf Bertram, Daniela Gregor, Christina Koepke, Stefanie Bargsten, Patrick Ott

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Abstract

The present invention relates to a process for the preparation of biodegradable polyurea/polyurethane microcapsules, preferably perfume-containing polyurea/polyurethane microcapsules, which have a balance of biodegradability, stability and performance compared to prior art microcapsules. In addition, the present invention relates to biodegradable polyurea/polyurethane microcapsules comprising at least one lipophilic active ingredient obtainable by the process of the invention. In another aspect, the invention described herein relates to the use of such microcapsules or microcapsule dispersions comprising the microcapsules according to the invention for the manufacture of household products, textile care products, detergents, fabric softeners, cleaning agents, scent boosters, scent lotion or scent enhancers, cosmetics, personal care products, agricultural products or pharmaceutical products. Ultimately, the present invention relates to consumer products comprising such microcapsules or microcapsule dispersions.

Claims20

Dependent claims

Process for preparing a biodegradable polyurea/polyurethane microcapsule comprising the following steps in this order:

(a) carrying out a first polymerisation and/or cross-linking step comprising:
(a1) providing an internal non-aqueous phase comprising at least one polyisocyanate having two or more isocyanate groups and at least one lipophilic active substance to be encapsulated;
(a2) providing an external aqueous phase comprising at least one protective colloid and optionally an emulsifier, and adjusting the pH of the external aqueous phase to a pH of from 1 to 5;
(a3) mixing the internal non-aqueous phase and the external aqueous phase to obtain an oil-in-water emulsion or dispersion;
and
(a4) adding at least one first amino acid or amino acid hydrochloride and a catalyst and adjusting the pH of the resulting emulsion or dispersion to a pH of 4 to 8;
(b) carrying out a second polymerisation and/or cross-linking step by adding at least one hydroxyl group donor;
(c) carrying out a third polymerisation and/or crosslinking step by adding at least one second amino acid and adjusting the pH of the emulsion or dispersion to a pH of 4 to 8, to obtain a microcapsule dispersion;
(d) optionally adding a further catalyst and adjusting the pH of the resulting microcapsule dispersion to a pH of 4 to 7;
(e) curing the microcapsule dispersion obtained from step (c) or (d) at a temperature of at least 60° C. for a period of at least 60 minutes;
(f) adding at least one release agent and incorporating the release agent into the shell of the microcapsule;
(g) post-curing the microcapsules obtained in step (f);
and optionally:
(h) separating the microcapsules from the microcapsule dispersion and, if necessary, drying the microcapsules or adjusting the viscosity of the slurry comprising the microcapsules by adding a thickening agent.

11 more elements

Biodegradable polyurea/polyurethane microcapsule comprising:

(i) a core comprising at least one hydrophobic agent;
and
(ii) a capsule shell comprising:
a reaction product of a polymerisation and/or cross-linking of at least one polyisocyanate having two or more isocyanate groups, in the presence of a protective colloid with at least one first amino acid or amino acid hydrochloride, a second polymerisation and/or cross-linking with at least one hydroxyl group donor, and a third polymerisation and/or cross-linking with at least one second amino acid;
at least one release agent;
and
a further polyester-based cross-linking matrix or further polyester-based cross-linking units from the reaction of protective colloid, hydroxyl group donor and release agent,
wherein the protective colloid is selected from the group consisting of diols, polyols, polyvinylpyrrolidone, maleic acid vinyl copolymers, sodium lignosulphonates, maleic anhydride/styrene copolymers, ethylene/maleic anhydride copolymers, copolymers of ethylene oxide, propylene oxide and acid esters of polyethoxylated sorbitol, sodium dodecyl sulphate, animal and vegetable polymers, and mixtures of the aforementioned compounds;
the hydroxyl group donor is a polyol having two or more hydroxyl functional groups, and the release agent is selected from the group consisting of long-chain, aliphatic, linear of branched, saturated or unsaturated carboxylic acids with 12 to 30° C. atoms, long-chain, aliphatic, linear or branched, saturated or unsaturated primary alcohols with 12 to 30 C atoms, esters of long-chain, aliphatic saturated carboxylic acids having 12 to 30 C atoms with long-chain, aliphatic primary alcohols having 12 to 30° C. atoms and mixtures of the aforementioned release agents.

6 more elements

Dependencies are inferred from the claim text.