US-12616948-B2 - Polyamide microcapsules

US12616948B2US 12616948 B2US12616948 B2US 12616948B2US-12616948-B2

Abstract

Described herein are a new process for the preparation of polyamide microcapsules, as well as such polyamide microcapsules. Further described are perfuming compositions and consumer products including such capsules, in particular perfumed consumer products in the form of home care or personal care products.

Inventors

Damien Berthier
Marlène Jacquemond
Lahoussine Ouali
Amal Elabbadi
Anaick NICOLAE

Assignees

FIRMENICH SA

Dates

Publication Date: 20260505
Application Date: 20191219
Priority Date: 20181219

Claims (9)

1 . A process for preparing a polyamide core-shell microcapsule slurry comprising the following steps: a) Dissolving at least one acyl chloride in a hydrophobic material to form an oil phase; b) Dispersing the oil phase obtained in step a) into a water phase comprising a first amino compound to form an oil-in-water emulsion; c) Performing a curing step to form polyamide microcapsules in the form of a slurry; wherein a stabilizer is added in the oil phase and/or in the water phase, wherein at least a second amino-compound is added in the water phase before the formation of the oil-in-water emulsion and/or in the oil-in-water emulsion obtained after step b), wherein the first amino compound is an amino-acid, wherein the polyamide microcapsules comprise a polyamide shell comprising the at least one acyl chloride, the first amino compound, the second amino compound, and the stabilizer, and wherein the stabilizer is a protein.
2 . The process according to claim 1 , further comprising the following step: following step b), adding to the oil-in-water emulsion obtained in step b) a second amino compound.
3 . The process according to claim 1 , wherein the acyl chloride is chosen from the group consisting of benzene-1,3,5-tricarbonyl chloride, benzene-1,2,4-tricarbonyl trichloride, benzene-1,2,4,5-tetracarbonyl tetrachloride, cyclohexane-1,3,5-tricarbonyl trichloride, isophthalyol dichloride, diglycolyl dichloride, succinic dichloride, and mixtures thereof.
4 . The process according to claim 2 , wherein the second amino compound is chosen from the group consisting of cystamine, cystamine hydrochloride, cystine, cystine hydrochloride, cystine dialkyl ester, cystine dialkyl ester hydrochloride, a xylylene diamine, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, L-lysine, L-Lysine ethyl ester, polyetheramines, ethylene diamine, diethylene triamine, spermine, spermidine, polyamidoamine (PAMAM), guanidine carbonate, chitosan, tris-(2-aminoethyl)amine, 3-aminopropyltriethoxysilane, L-arginine and mixtures thereof.
5 . The process according to claim 2 , wherein the first amino compound and the second amino compound are different.
6 . The process according to claim 2 , wherein the molar ratio between the functional group NH2 of the second amino compound and the functional group COCl of the acyl chloride is between 0.01 and 7.5.
7 . The process according to claim 1 , wherein the weight ratio between the acyl chloride and the hydrophobic material is between 0.01 and 0.09.
8 . The process according to claim 1 , wherein the first amino-compound is chosen from the group consisting of L-Lysine, L-Arginine, L-Histidine, L-Tryptophane, L-Serin, L-Glutamine, L-Threonine and mixtures thereof.
9 . The process according to claim 1 , wherein the stabilizer chosen from the group consisting of whey protein, casein, sodium caseinate, bovine serum albumin, and mixtures thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a U.S. National Phase Application of International Patent Application No. PCT/EP2019/086321, filed Dec. 19, 2019, which claims the benefit of priority to European Patent Application No. 18214089.7, filed Dec. 19, 2018, the entire contents of each of which are hereby incorporated by reference herein. TECHNICAL FIELD The present invention relates to a new process for the preparation of polyamide microcapsules. Polyamide microcapsules are also an object of the invention. Perfuming compositions and consumer products comprising said microcapsules, in particular perfumed consumer products in the form of home care or personal care products, are also part of the invention. BACKGROUND OF THE INVENTION One of the problems faced by the perfumery industry lies in the relatively rapid loss of olfactive benefit provided by odoriferous compounds due to their volatility, particularly that of “top-notes”. In order to tailor the release rates of volatiles, delivery systems such as microcapsules containing a perfume are needed to protect and later release the core payload when triggered. A key requirement from the industry regarding these systems is to survive suspension in challenging bases without physically dissociating or degrading. This is referred to as stability for the delivery system. For instance, fragranced personal and household cleansers containing high levels of aggressive surfactant detergents are very challenging for the stability of microcapsules. Polyurea and polyurethane-based microcapsule slurry are widely used for example in perfumery industry for instance as they provide a long lasting pleasant olfactory effect after their applications on different substrates. Those microcapsules have been widely disclosed in the prior art (see for example WO2007/004166 or EP 2300146 from the Applicant). There is still a need to provide new microcapsules, while not compromising on the performance of the microcapsules, in particular in terms of stability in a challenging medium such as a consumer product base, as well as in delivering a good performance in terms of active ingredient delivery, e.g. olfactive performance in the case of perfuming ingredients. The present invention is proposing a solution to the above-mentioned problem by providing new polyamide microcapsules and a process for preparing said microcapsules. SUMMARY OF THE INVENTION It has now been surprisingly found that performing core-shell microcapsules encapsulating hydrophobic material could be obtained by reacting an acyl chloride with two amino compounds during the process, wherein the amino compounds are preferably added successively during the process. The process of the invention therefore provides a solution to the above-mentioned problems as it allows preparing microcapsules with the desired stability in challenging bases. In a first aspect, the present invention relates to a process for preparing a polyamide core-shell microcapsule slurry comprising the following steps: a) Dissolving at least one acyl chloride in a hydrophobic material, preferably a perfume to form an oil phase;b) Dispersing the oil phase obtained in step a) into a water phase comprising a first amino-compound to form an oil-in water emulsion;c) Performing a curing step to form polyamide microcapsules in the form of a slurry;wherein a stabilizer is added in the oil phase and/or in the water phase, andwherein at least a second amino-compound is added in the water phase before the formation of the oil-in-water emulsion and/or in the oil-in water emulsion obtained after step b). A second object of the invention is a polyamide core-shell microcapsule comprising: an oil based core comprising a hydrophobic material, preferably a perfume, anda polyamide shell comprising: an acyl chloride,a first amino compound,a second amino compound. A third object of the invention is a polyamide core-shell microcapsule slurry obtainable by the process as defined above. A perfuming composition comprising: (i) microcapsule as defined above, wherein the hydrophobic material comprises a perfume,(ii) at least one ingredient selected from the group consisting of a perfumery carrier and a perfumery base(iii) optionally at least one perfumery adjuvantis another object of the invention. Another object of the invention is a consumer product comprising: a personal care active base, andmicrocapsules as defined above or the perfuming composition as defined above,wherein the consumer product is in the form of a personal care composition. Another object of the invention is a consumer product comprising: a home care or a fabric care active base, andmicrocapsules as defined above or the perfuming composition as defined above,wherein the consumer product is in the form of a home care or a fabric care composition. DETAILED DESCRIPTION OF THE INVENTION Unless stated otherwise, percentages (%) are meant to designate a percentage by weight of a composition.