Biodegradable polyurea / polyurethane microcapsules

Abstract

The present invention relates to a process for the preparation of biodegradable polyurea / polyurethane microcapsules, preferably fragrance-containing polyurea / polyurethane microcapsules, which have enhanced biodegradability compared to prior art microcapsules. Furthermore, the present invention relates to a biodegradable polyurea / polyurethane microcapsule comprising at least one lipophilic active substance obtainable according to the process of the present invention. In another aspect, the present invention described herein relates to the use of such microcapsules or of a polyurethane microcapsule dispersion comprising the microcapsules described in the present invention for the manufacture of a household product, a textile care product, a detergent, a fabric softener, a cleaning agent, a fragrance booster, a fragrance lotion and a fragrance enhancer, a cosmetic, a personal care product, an agricultural product, a pharmaceutical product or a paper printing ink. Finally, the present invention relates to a consumer product comprising such microcapsules or microcapsule dispersion.

Description

TECHNICAL FIELD

[0001] The present invention relates to a process for the preparation of biodegradable polyurea / polyurethane microcapsules, preferably fragrance-containing polyurea / polyurethane microcapsules, comprising at least one lipophilic active substance. The microcapsules have a balance of biodegradability, stability and performance compared to the prior art microcapsules. Furthermore, the present invention relates to a biodegradable polyurea / polyurethane microcapsule comprising at least one lipophilic active substance obtainable according to the process of the present invention. In another aspect, the present invention described herein relates to the use of such microcapsules or polyurethane microcapsule dispersions comprising the microcapsules of the present invention for the manufacture of household products, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters, fragrance lotions and fragrance enhancers, cosmetics, personal care products, agricultural products, pharmaceutical products or paper printing inks. Finally, the present invention relates to a consumer product comprising such microcapsules or microcapsule dispersions. BACKGROUND

[0002] Microcapsules are particles composed of a core and a wall material surrounding the core, wherein the core can be a solid, liquid or gaseous substance surrounded by a polymerendichte, by a permeable or semipermeable wall material. During the preparation process, the polymer from the starting ingredients is emulsified and coagulated or interfacially polymerized and precipitates on the substance to be encapsulated, which is thus immobilized. The core is also referred to as the internal phase. The wall, which is thus immobilized, is also designated as the external phase, shell or coating. The diameter of the microcapsules usually varies in the range of 1 to 1000 pm. The wall thickness is usually 0.5 to 150 pm. The usual loading is 25 to 95 wt.-%, but can also be 1 to 99 wt.-%.

[0003] Furthermore, the aim of encapsulation is to protect the encapsulated substance or active substance, to release them in a targeted manner at a specific time, to transfer liquids into a controllable powder form, to delay the loss of volatile components (for example in the case of fragrances or flavorings), to prevent premature chemical reactions with other mixture components, or to better handle before or during processing. Lipophilic or hydrophobic active substances, such as fragrances or flavorings, can be easily incorporated into many different application formulations by encapsulation.

[0004] The content of the microcapsules can be released in various ways and in particular based on one of the following described mechanisms: mechanical destruction of the capsule by crushing or shearing; destruction of the capsule by melting of the wall material, destruction of the capsule by dissolution of the wall material or diffusion of the active substance through the capsule wall.

[0005] For the preparation of microcapsules, a variety of shell materials are known. The shell can be made of natural, semi-synthetic or synthetic materials. Natural shell materials include, for example, gum arabic, agar agar, agarose, maltodextrin, alginic acid or its salts, such as sodium alginate or calcium alginate, fats and fatty acids, cetyl alcohol, collagen, chitosan, lecithin, gelatin, albumin, shellac, polysaccharides such as starch or dextran, polypeptides, protein hydrolysates, sucrose and waxes. Semi-synthetic shell materials include, in particular, chemically modified celluloses, in particular cellulose esters and cellulose ethers, such as cellulose acetate, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose and carboxymethyl cellulose, and also starch derivatives, in particular starch ethers and starch esters. Synthetic shell materials are, for example, polymers such as polyacrylates, polyamides, polyvinyl alcohol or polyvinylpyrrolidone.

[0006] Depending on the type of shell material and the method of preparation, the microcapsules produce different properties in terms of diameter, size distribution and physical and / or chemical properties.

[0007] Polyurea microcapsules or polyurea / polyurethane microcapsules formed by polymerization of polyisocyanates with polyamines and / or diols or polyols are known capsules which are used in various technical fields, including perfumery.

[0008] For example, polyurea microcapsules obtained by reaction of two polyisocyanates and one polyamine are described in WO 2011 / 161229 or WO 2011 / 160733. According to WO 2011 / 161229 or WO 2011 / 160733, the polyurea microcapsules are prepared in the presence of polyvinylpyrrolidone (PVP) as protective colloid. WO 2012 / 107323 discloses polyurea microcapsules having a polyurea shell comprising the reaction product of polyisocyanate with guanazole (3,5-diamino)-1,2,4-triazole and an amino acid in the presence of an anionic stabilizer or surfactant such as an anionic polyvinyl alcohol. EP 0537467 B describes microcapsules prepared from polyisocyanates containing polyethylene oxide groups in the presence of a stabilizer such as polyvinyl alcohol. According to WO 2007 / 096592, microencapsulation can be carried out in an oil phase emulsified in a continuous aqueous phase, which is usually stabilized by a surfactant system such as polyvinyl alcohol or its carboxylated and sulfonated derivatives.

[0009] The above exemplary delivery systems from the prior art have both good stability, i.e. the ability to retain the active substance and thus the ability of the capsules to avoid loss of volatile ingredients, and good performance, e.g. in the case of perfume capsules, the release of the perfume.

[0010] However, the microcapsules of the prior art described above have the disadvantage that the polymeric capsule wall or capsule shell material requires a large amount of polymer to ensure sufficient stability and not to suffer too great a loss of drug. Furthermore, the microcapsules bring plastic into the environment, where the plastic causes problems as "microplastic".

[0011] Due to the increasing criticism of the environmental impact of plastic particles by the public and due to the increasing pressure on society to address environmental problems, there is a growing demand for bio-based and biodegradable solutions. Microcapsules need to develop new materials to reduce microplastics in the environment. In this context, the focus is on bio-based and biodegradable materials.

[0012] Against this background, there is therefore a need, on the one hand, to provide polyurea / polyurethane microcapsules with outstanding stability and outstanding release properties for the respective application, and on the other hand to provide polyurea / polyurethane microcapsules which are primarily or almost completely biodegradable.

[0013] However, the task of reducing the number of microplastics in the environment with biodegradable materials is not trivial in the case of microcapsules, since the functionalities desired for microcapsules, such as olfactory properties and positive secondary properties such as high stability and toxicological stability, conflict with the requirement for rapid biodegradation in many applications.

[0014] It is particularly difficult to produce microcapsules which have both good stability and good release of active substances. The retention capacity of the active substances, and thus the ability of the capsules to avoid loss of volatile ingredients, is particularly dependent on the stability of the capsules in the product base. However, a capsule which is particularly stable does not automatically exhibit good biodegradability.

[0015] With increasing degree of crosslinking, the stability of the microcapsules increases, but at the same time the biodegradability of the capsule shell also decreases. For very stable microcapsules, properties such as sensory properties are lower, since the number of microcapsules which are broken and release the active substance by pressure, friction, etc. is reduced. If the microcapsules are not very stable, they are destroyed during storage and do not exhibit properties either.

[0016] Against this background, the overall task of the present invention is to provide a process for producing microcapsules which can provide, on the one hand, microcapsules with a lower polymer content which at the same time have high stability and excellent release properties of the encapsulated active substances and which have biodegradability as high as possible.

[0017] It has surprisingly been found that this task can be solved by producing polyurea / polyurethane microcapsules using amino acids and a release agent (Trennmittels), which is placed in the microcapsule shell. SUMMARY

[0018] The current problem is addressed by the subject matter of the independent claims. The wording of the dependent claims and the following description provide preferred embodiments.

[0019] Therefore, the first subject of the present invention relates to a method for preparing biodegradable polyurea / polyurethane microcapsules, the method comprising the following steps in sequence:

[0020] (a) Performing the first polymerization and / or crosslinking step, including:

[0021] (a1) Provides 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;

[0022] (a2) Provides an external aqueous phase, comprising at least one protective colloid and an optional emulsifier;

[0023] (a3) Mix the internal non-aqueous phase and the external aqueous phase to obtain an oil-in-water emulsion;

[0024] (a4) Add at least one first amino acid or amino acid hydrochloride and a catalyst;

[0025] (b) A second polymerization and / or crosslinking step is carried out by adding at least one hydroxyl donor;

[0026] (c) A microcapsule dispersion is obtained by adding at least one second amino acid, particularly by carrying out a third polymerization and / or crosslinking step at a temperature of at least 60°C;

[0027] (d) Curing the microcapsule dispersion at a temperature of at least 60°C for at least 60 minutes;

[0028] (e) Add at least one release agent and place the release agent in the microcapsule shell;

[0029] (f) Post-curing the microcapsules obtained in step (e);

[0030] And optional:

[0031] (g) Optionally, the microcapsules can be separated from the microcapsule dispersion and the microcapsules can be dried or adjusted by adding a thickener.

[0032] Viscosity of the capsule syrup.

[0033] Furthermore, the subject of this invention is a biodegradable polyurea / polyurethane microcapsule comprising at least one lipophilic active substance prepared according to the method of the invention.

[0034] Another aspect of the present invention is a biodegradable polyurea / polyurethane microcapsule comprising:

[0035] (i) a core comprising at least one hydrophobic agent; and

[0036] (ii) a capsule shell comprising

[0037] - a reaction product of the polymerization and / or crosslinking of at least one polyisocyanate having two or more isocyanate groups with at least one first amino acid or amino acid hydrochloride, of the further polymerization and / or crosslinking with at least one hydroxyl donor, and of the further polymerization and / or crosslinking with at least one second amino acid in the presence of at least one protective colloid; and

[0038] - at least one release agent.

[0039] Finally, the present application relates in another aspect to the use of the biodegradable polyurea / polyurethane microcapsules or of the dispersion consisting of the polyurea / polyurethane microcapsules of the present application for the manufacture of a household product, a textile care product, a detergent, a fabric softener, a cleaning agent, a fragrance booster, a fragrance lotion or fragrance enhancer, a cosmetic, a personal care product, a fragrance composition, an agricultural product, a pharmaceutical product or a paper printing ink, and to a consumer product prepared therefrom.

[0040] Surprisingly, it was found within the scope of the present application that the targeted polymerization and / or crosslinking of a polyisocyanate having at least two or more isocyanate groups with a first amino acid or amino acid hydrochloride, followed by the polymerization and / or crosslinking with a hydroxyl donor, and the further polymerization and / or crosslinking with a second amino acid, and the addition of a release agent and the placement of the release agent into the microcapsule shell, in combination of the above-mentioned steps, leads to stable microcapsules, thus enabling an efficient encapsulation of active substances and a subsequent targeted release of these active substances, while the microcapsules, due to their bio-based and biodegradable components, such as amino acids and release agents, at the same time have a good biodegradability.

[0041] Furthermore, by using amino acids and release agents, it is possible to reduce the polymer content of the capsule wall or capsule shell material without affecting the stability of the microcapsule wall. Moreover, by incorporating a release agent into the microcapsule shell, the biodegradability of the capsule wall or capsule shell material is promoted.

[0042] These and other aspects, features, and advantages of the present application will become apparent to those skilled in the art from a reading of the following detailed description and the claims. In this case, every feature from one aspect of the present application can be used or replaced in another aspect of the present application. The examples contained herein illustrate the present application without limiting it.

[0043] The term "at least one" or "minimum one" or "one or more" as used herein means one or more, for example 2, 3, 4, 5, 6, 7, 8, 9 or more.

[0044] The term "and / or" means that the connection is present or an alternative is provided.

[0045] Numerical examples given in the form "x to y" include the values above and below the given range. If several preferred numerical ranges are specified in this format, all ranges formed by the combination of the different lower and upper limits are also determined. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is an optical microscope image of microcapsules according to the present application. The microcapsules were prepared with hexamethylene diisocyanate and 4,4'-diphenylmethane diisocyanate as starting materials in a ratio of 75:25. In addition lysine*HCI was used as the first amino acid, glycerol as the hydroxyl donor and arginine as the second amino acid. DABCO was used as catalyst and modified starch as protective colloid; in addition beeswax was used as release agent. The optical micrograph was made using an Olympus BX51. The shown bar corresponds to 100 pm.

[0047] Figure 2 shows a graph of the particle size distribution (d(0.5) value) of microcapsules according to the present application and prior art microcapsules based on a polyurea / polyurethane structure without release agent. For determining the particle size distribution a MALVERN Mastersizer 3000 was used. The corresponding calculation is based on the Mie theory.

[0048] Figure 3 shows a graph of the results of the infrared spectroscopy analysis of microcapsules according to the present application and prior art microcapsules, i.e. microcapsules based on a polyurea / polyurethane structure without release agent. The analysis was performed by means of an AT (attenuated total reflectance) R infrared spectrometer. Note: in Figure 3 , the decimal point on the absorption axis is marked by a dot instead of a comma as decimal separator.

[0049] Figure 4 shows a graph of the biodegradability of microcapsules according to the present application and sodium benzoate and a toxicity control (a mixture of microcapsules according to the present application and sodium benzoate) according to OECD 301 F.

[0050] Figure 5 shows a graph of the results of the sensory evaluation of microcapsules according to the present application and prior art microcapsules, i.e. microcapsules based on a polyurea / polyurethane structure without release agent. Note: in Figure 5 , the decimal point on the intensity axis is marked by a dot instead of a comma as decimal separator.

[0051] Figure 6 shows a graph of the general correlation between microcapsule stability, performance and biodegradability and the degree of crosslinking. DETAILED DESCRIPTION

[0052] In a first aspect, the present application relates to a process for the preparation of biodegradable polyurea / polyurethane microcapsules, preferably a process for the preparation of perfume capsules, the process comprising the following steps in this order:

[0053] (a) performing a first polymerization and / or crosslinking step, comprising:

[0054] (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;

[0055] (a2) providing an external aqueous phase comprising at least one protective colloid and an optional emulsifier;

[0056] (a3) mixing the internal non-aqueous phase and the external aqueous phase to obtain an oil-in-water emulsion;

[0057] (a4) adding at least one first amino acid or amino acid hydrochloride and a catalyst;

[0058] (b) performing a second polymerization and / or crosslinking step by adding at least one hydroxyl donor;

[0059] (c) performing a third polymerization and / or crosslinking step by adding at least one second amino acid, in particular at a temperature of at least 60 °C, to obtain a microcapsule dispersion;

[0060] (d) curing the microcapsule dispersion at a temperature of at least 60 °C for at least 60 minutes;

[0061] (e) adding at least one release agent and incorporating the release agent into the microcapsule shell;

[0062] (f) post-curing the microcapsules obtained in step (e);

[0063] and optionally:

[0064] (g) optionally separating the microcapsules from the microcapsule dispersion and optionally drying the microcapsules or adjusting the viscosity of the microcapsule slurry by adding a thickening agent.

[0065] In the context of the present application, microcapsules are understood to be microparticles having a capsule shell or wall and as an internal core material at least one or more active substances. The active substances are preferably lipophilic or hydrophobic active substances. Such active substances are not or only sparingly soluble in water, but readily soluble in fats and oils. For the purposes of the present application, the terms "microcapsules" or "capsules" and "lipophilic" or "hydrophobic" are synonymous in the present application.

[0066] Within the scope of the present application, the capsule shell or capsule wall is preferably composed of a plurality of cross-linked matrices or cross-linked units, which preferably have different compositions and are generated in the preparation of the microcapsules according to the present application from a plurality of process steps or process sequences, in particular cross-linking steps, thus forming a three-dimensional network.

[0067] The cross-linked matrices or cross-linked units in the context of the present application are complexes or networks of starting ingredients for building the microcapsule shell, which are built by linear or three-dimensional polymerization and / or cross-linking between and / or with the functional groups of the starting ingredients and / or with other ingredients of the microcapsule shell and / or other ingredients embedded in the microcapsule shell. In the course of the process according to the present application, the plurality of cross-linked matrices can in turn cross-link with each other by further cross-linking and form a three-dimensional structure for building the microcapsule shell or the microcapsule wall. The cross-linked units or cross-linked matrices together constitute the capsule shell or capsule wall.

[0068] In a further preferred variant of the present application, the capsule shell or capsule wall comprises at least polyurea and polyurethane cross-linked matrices or cross-linked units, and a release agent, respectively, which is incorporated into the capsule shell or capsule wall.

[0069] In the first step (a) of the process according to the present application, a first polymerization and / or cross-linking (a) is carried out. To this end, an internal non-aqueous phase (al) is provided, which comprises at least one isocyanate or polyisocyanate having two or more isocyanate groups and at least one lipophilic active substance to be encapsulated.

[0070] The polyurea / polyurethane microcapsules according to the present application are prepared using at least one or more polyisocyanates.

[0071] The at least one isocyanate or polyisocyanate having two or more isocyanate groups used in a process according to the present application for the preparation of biodegradable polyurea / polyurethane microcapsules has at least two isocyanate groups for the formation of a polymer network by polymerization, which forms the capsule shell or capsule wall.

[0072] Polyisocyanates are R-substituted organic derivatives of isocyanic acid (HN=C=0) (R-N=C=0). Organic isocyanates are compounds in which an isocyanate group (-N=C=0) is bound to an organic radical. Polyfunctional isocyanates or polyisocyanates are compounds which contain at least two or more, i.e. 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200 or more isocyanate groups (-N=C=0) in the molecule. Polyisocyanates having two isocyanate groups are also referred to as diisocyanates.

[0073] The polyisocyanates can be aliphatic, cycloaliphatic, hydrogenaromatic, aromatic or heterocyclic isocyanates or polyisocyanates. Furthermore, the polyisocyanates according to the application can be linear or branched.

[0074] Polyisocyanates, especially aromatic polyisocyanates, are very reactive compounds. The polyaddition of polyisocyanates with diols or polyols is the basis of polyurethane chemistry and the polyaddition of polyisocyanates with amines is the basis of polyurea chemistry.

[0075] According to the application at least difunctional, preferably polyfunctional polyisocyanates are used, i.e. all aliphatic, cycloaliphatic and aromatic isocyanates are suitable as long as they have at least two reactive isocyanate groups.

[0076] Particularly preferred are aliphatic, cycloaliphatic, hydrogenaromatic, aromatic or heterocyclic polyisocyanates and substitution products thereof as well as mixtures of the above-mentioned monomeric or oligomeric compounds. Of the above-mentioned polyisocyanates, aliphatic and / or aromatic compounds are preferably used.

[0077] In a preferred embodiment of the process according to the application, the polyisocyanate comprises on average 2 to 5 -N=C=0 functional groups. Included therein are, for example, aliphatic, cycloaliphatic and aromatic di-, tri- and higher polyisocyanates.

[0078] Of the above-mentioned polyisocyanates, diisocyanates and polyisocyanates having three functional groups -N-C=0 are particularly preferred and are therefore used preferentially in the implementation of the application. Diisocyanates of the general structure O=C=N-R-N=C=0, in which R represents an aliphatic, cycloaliphatic or aromatic radical, are preferably used. Preferably, the radicals have five or more carbon atoms.

[0079] In a preferred embodiment of the process according to the application, at least one polyisocyanate having two or more isocyanate groups is selected from the group of aliphatic polyisocyanates and / or aromatic polyisocyanates. In a more preferred variant of the process according to the application, the at least one polyisocyanate is a combination of two different aliphatic polyisocyanates or a combination of aliphatic and aromatic polyisocyanates.

[0080] Due to the number of functional groups, an optimized crosslinking or network of the capsule wall is achieved, thus providing microcapsules with prolonged active substance release and good stability in consumer products.

[0081] In a preferred variant of the process according to the application, the polyisocyanate is an aliphatic polyisocyanate.

[0082] The term "aliphatic polyisocyanate" refers to any non-aromatic polyisocyanate molecule. Furthermore, the molecule comprises at least two isocyanate groups, i.e. at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200 or more isocyanate groups directly bound to a corresponding number of different carbon atoms of the same aliphatic molecule and derivatives of such compounds.

[0083] The aliphatic polyisocyanate molecule having at least two isocyanate groups, i.e. at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200 or more isocyanate groups can also be linear, branched or cyclic and can have any substitution, such as including aliphatic substituents, aromatic substituents, one or more heteroatoms, such as nitrogen, oxygen, phosphor and / or sulfur, halogens, such as fluorine, chlorine, bromine and / or iodine and / or other functional groups, such as alkoxy groups.

[0084] The linear aliphatic polyisocyanate molecule is preferably selected from C2 to C20 linear alkyl groups, preferably from C3 to C15 linear alkyl groups, C4 to C12 linear alkyl groups, C5 to C10 linear alkyl groups, C6 to C9 linear alkyl groups or C7 to C8 linear alkyl groups. Preferably, the linear aliphatic molecule does not comprise an aromatic structure.

[0085] The branched aliphatic polyisocyanate molecule is preferably selected from C2 to C20 branched alkyl groups, preferably from C3 to C15 branched alkyl groups, C4 to C12 branched alkyl groups, C5 to C10 branched alkyl groups, C6 to C9 branched alkyl groups and C7 to C8 branched alkyl groups.

[0086] The shorter the carbon chain of the polyisocyanate molecule, the higher the reaction rate compared to long chain analogues.

[0087] The cyclic aliphatic polyisocyanate molecule comprises at least 1, i.e. 1, 2, 3, 4 or more non-aromatic cyclic structures, wherein the cyclic structures themselves are preferably composed of carbon atoms only. Obviously, the carbon atoms of the cyclic structures can carry suitable substituents. The at least 1 ring structure is preferably composed of 3, 4, 5, 6, 7 or 8 membered rings independently. Preferably, the cyclic aliphatic molecule comprises 2 to 20 carbon atoms, such as 3 to 15 carbon atoms, 4 to 12 carbon atoms, 5 to 10 carbon atoms, 6 to 9 carbon atoms or 7 to 8 carbon atoms.

[0088] In another variant of the process according to the present application, the polyisocyanate is an aromatic polyisocyanate. The term "aromatic polyisocyanate" refers to all polyisocyanate compounds having two or more isocyanate groups directly bound to an aromatic carbon atom and including, for example, phenyl, tolyl, xylyl, naphthyl or diphenyl units as aromatic components, as well as derivatives of such polyisocyanate compounds.

[0089] The reaction of aromatic polyisocyanates is significantly faster than that of aliphatic polyisocyanates and is therefore preferred for the process according to the application.

[0090] Linear, branched or cyclic aliphatic or aromatic polyisocyanates can be present as monomers or polymers. A monomeric polyisocyanate is not connected to another molecule, in particular not to a molecule via one or more crosslinkers. A polymeric polyisocyanate comprises at least two monomers which are connected to each other via one or more crosslinkers. The at least two monomers are not necessarily identical monomers, but can also be different monomers. A polymeric polyisocyanate preferably comprises at least 2 or more monomers, i.e. at least 2, 3, 4, 5, 10, 20, 30, 40, 50, 100 or more monomers which are connected together via at least one crosslinker.

[0091] Linear, branched or cyclic aliphatic or aromatic polyisocyanates preferably have a limited size / molecular weight, allowing a reaction with one or more crosslinkers. Examples of suitable molecular weights include preferably from about 100 g / mol to 5-10 4 g / mol, preferably from 120 g / mol to 2-10 4 g / mol, from 140 g / mol to 10 4 g / mol, from 160 g / mol to 5-10 3 g / mol, from 180 g / mol to 2-10 3 g / mol, from 200 g / mol to 10 3 g / mol, from 220 g / mol to 900 g / mol, from 240 g / mol to 800 g / mol, from 260 g / mol to 700 g / mol, from 280 g / mol to 600 g / mol, from 300 g / mol to 500 g / mol, from 320 g / mol to 450 g / mol or from 340 g / mol to 400 g / mol.

[0092] Any number of linear, branched and / or cyclic aliphatic and / or aromatic polyisocyanates can be used. For example, at least one, i.e. at least 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 different linear aliphatic polyisocyanates are used. For example, at least one, i.e. at least 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 different branched aliphatic polyisocyanates are used. For example, at least one, i.e. at least 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 different branched cyclic polyisocyanates are used.

[0093] Derivatives of linear, branched and / or cyclic aliphatic polyisocyanates are preferably used. Derivatives as used herein are understood in their broadest sense as compounds which are obtained from a compound by a chemical reaction. Examples of derivatives include oligomers and / or adducts of the above-mentioned linear or branched aliphatic polyisocyanates. Preferred oligomers are biurets, isocyanurates, uretdiones, imino oxadiazindiones, preferred adducts are trimethylolpropane adducts. These oligomers / adducts are well known in the art and are disclosed, for example, in US 4855490 A or US 4144268 A.

[0094] Preferably, the aliphatic polyisocyanate is present only in monomeric form and / or dimeric form (as isocyanate) or oligomeric form.

[0095] Derivatives of linear, branched or cyclic polyisocyanates and / or derivatives of mixtures thereof can also be obtained by reacting polyisocyanates with polyols (e.g. glycerol), polyamines and polythiols (e.g. dimercapto propanol).

[0096] The isocyanate compounds according to the above definition expressly include the various isomers, alone or in combination, as they exist. For example, methylene bis-(cyclohexyl isocyanate) (H12MDI) includes 4,4'-methylene bis-(cyclohexyl isocyanate), 2,4'-methylene bis-(cyclohexyl isocyanate) and / or 2,2'-methylene bis-(cyclohexyl isocyanate).

[0097] Exemplary aliphatic polyisocyanates include those commercially available, such as BAYHYDUR N304 and BAYHYDUR N305, which are aliphatic water-dispersible polyisocyanates based on hexamethylene diisocyanate, DESMODUR N3400, DESMODUR N3600, DESMODUR N3700 and DESMODUR N3900, which are low viscosity, multifunctional aliphatic polyisocyanates based on hexamethylene diisocyanate, and DESMODUR 3600 and DESMODUR N100, which are aliphatic polyisocyanates based on hexamethylene diisocyanate, each of which is available from Bayer Corporation, Pittsburgh, PA.

[0098] According to another preferred variant of the present application, the linear or branched aliphatic polyisocyanate is or is selected from the group consisting of pentamethylene diisocyanate (PDI, such as Stabio D-370N or D-376N from Mitsui Chemicals Inc., Japan), hexamethylene diisocyanate (HDI), lysine triisocyanate and lysine diisocyanate and derivatives thereof, preferably wherein each of said derivatives comprises more than one isocyanate group and, where appropriate, also one or more groups selected from the group consisting of biuret, isocyanurate, uretdione, iminooxadiazinedione and trimethylolpropane adducts and / or wherein said cyclic aliphatic polyisocyanate is or is selected from the group consisting of isophorone diisocyanate (IPDI), 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI, such as Takenate 600 from Mitsui Chemicals Inc., Japan), 1,2-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, methylene bis(isocyanatocyclohexane) (H12MDI) and derivatives thereof, preferably wherein each derivative comprises more than one isocyanate group and, where appropriate, also one or more groups selected from the group consisting of biuret, isocyanurate, uretdione, iminooxadiazinedione and trimethylolpropane adducts of H6XDI, in particular TMP adducts of H6XDI, such as Takenate D-120N from Mitsui Chemicals Inc., Japan.

[0099] Aliphatic polyisocyanates obtained from renewable raw materials, such as PDI (Stabio D-370N or D-376N from Mitsui Chemicals Inc., Japan), are particularly preferred. It was found that such aliphatic polyisocyanates obtained from renewable raw materials do not affect the quality / properties of the core-shell capsules.

[0100] Other suitable commercially available polyisocyanates include LUPRANATM 20 (BASF) with an average n of 0.7; PAPI 27 (Dow Chemical) with an average n of 0.7; MONDUR MR (Bayer) with an average n of 0.8; MONDUR MR Light (Bayer) with an average n of 0.8; MONDUR 489 (Bayer) with an average n of 1.0; poly[(phenyl isocyanate)-co-formaldehyde] (Aldrich Chemical, Milwaukee, WI), other isocyanate monomers such as DESMODUR N3200 (Bayer) and TAKENATE D110-N (Mitsui Chemicals Corporation, Rye Brook, NY). Other representative polyisocyanates include those with the designations TAKENATE D-110N (Mitsui), DESMODUR L75 (Bayer), and DESMODUR IL (Bayer).

[0101] In a preferred variant, the polyisocyanate used in the manufacture of the polyurea / polyurethane microcapsules according to the application is used as the sole polyisocyanate component, i.e. no other different polyisocyanate component is added.

[0102] Examples of polyisocyanate monomers which can be used according to the present application and which comprise at least two polyisocyanate groups are ethylene diisocyanate, trimethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, ethylene diisothiocyanate, tetramethylene diisothiocyanate, hexamethylene diisothiocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, a mixture of 1,3-phenylene diisocyanate and 1,4-phenylene diisocyanate, p-phenylene diisothiocyanate, m-xylylene-1,4-diisothiocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, m-xylylene-1,4-diisocyanate, p-xylylene-1,3-diisocyanate, and a mixture of m-xylylene-1,4-diisocyanate and p-xylylene-1,3-diisocyanate, 2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate, a mixture of 2,4-hexahydrotoluene diisocyanate and 2,6-hexahydrotoluene diisocyanate, hexahydro-1,3-phenylene diisocyanate, hexahydro-1,4-phenylene diisocyanate, a mixture of hexahydro-1,3-phenylene diisocyanate and hexahydro-1,4-phenylene diisocyanate, 1,3-bis(isocyanatocyclohexane), 1,3,5-trimethylbenzene-2,4-diisocyanate, 1,3,5-triisopropylbenzene-2,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, triphenylmethane-4,4',4"-triisocyanate, toluene-2,4,6-triisocyanate, dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate or mixtures of the aforementioned compounds.

[0103] The industrially produced diisocyanates and polyisocyanates are preferably as polymerizable compounds having at least two polyisocyanate groups, such as TDI: toluene diisocyanate (isomeric mixture of 2,4- and 2,6-toluene diisocyanate in a ratio of 80:20), HDI: hexamethylene-1,6-diisocyanate (Desmodur®), IPDI: isophorone diisocyanate or DMDI: diphenylmethane-4,4'-diisocyanate.

[0104] Other particularly preferred monomeric polyisocyanate compounds are diisocyanates such as 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,5-diisocyanato-2,2- dimethylpentane, 2,2,4- and 2,4,4-trimethyl-1,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3- and 1,4-diisocyanatocyclohexane, 1 -isocyanato-3,3,5-trimethyl-5- isocyanatomethylcyclohexane (isophorone diisocyanate), 4,4'- diisocyanatodicyclohexylmethane, 2,4- and 2,6-diisocyanatomethylcyclohexane and mixtures thereof. In principle, also aromatic polyisocyanates can be used, for example toluene diisocyanate or 4,4'-diisocyanatodiphenylmethane.

[0105] Other specific examples of diisocyanates include, for example, 1,5- naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), hydrogenated MDI (H12MDI), xylene diisocyanate (XDI), tetramethyl xylene diisocyanate (TMXD1) 4,4'-diphenyl dimethyl methane diisocyanate, dialkyl diphenyl methane diisocyanate and tetraalkyl diphenyl methane diisocyanate, 4,4'-dibenzyl diisocyanate, 1,3- and 1,4-phenylene diisocyanate, isomers of toluene diisocyanate (TDI), as applicable, in mixtures, 1 -methyl-2,4-diisocyanatocyclohexane, 1,6-diisocyanato-2,2,4- trimethylhexane, 1,6-diisocyanato-2,4,4-trimethylhexane, 1 -isocyanatomethyl- 3-isocyanato-1,5,5-trimethylcyclohexane, chlorinated and brominated diisocyanates, phosphorus-containing diisocyanates, 4,4'-diisocyanatophenyl perfluoroethane, tetramethyldiamyl-1,4-diisocyanate, butane-1,4-diisocyanate (HDI), hexane-1,6-diisocyanate, dicyclohexylmethane diisocyanate, cyclohexane-1,4-diisocyanate, ethylene diisocyanate, phthalic diisocyanate ethyl ester, and polyisocyanates having reactive halogen atoms such as 1 -chloromethylphenyl-2,4-diisocyanate-1,2-bromo-3,3-bis-chloromethyl ether-4,4'-diphenyl diisocyanate.

[0106] Surprisingly, especially long-chain aliphatic diisocyanates with 6, 7, 8, 9, 10 or even more carbon atoms can form more stable capsule shells or capsule walls.

[0107] In a particularly preferred embodiment, the internal non-aqueous phase comprises a mixture of two or more different polymerizable polyisocyanates, for example polyisocyanates with different chain lengths, which can form copolymers.

[0108] Derivatives of polyisocyanates which can be prepared by modifying the above-mentioned diisocyanates or mixtures thereof according to known methods, for example containing uretdione, urethane, isocyanurate, biuret and / or allophanate groups, can also be used in the process according to the application in the stated proportions.

[0109] Particularly preferred is a combination of at least two different, preferably aliphatic, polyisocyanates, or a combination of at least one aliphatic and at least one aromatic polyisocyanate.

[0110] Such combinations take advantage of the different reaction rates of polyisocyanates: aromatic polyisocyanates react significantly faster than aliphatic polyisocyanates, and short-chain aliphatic polyisocyanates, i.e. aliphatic polyisocyanates having from 1 to 5 carbon atoms, preferably from 3 to 5 carbon atoms, react more rapidly than the long-chain analogues.

[0111] Thus, in another preferred modification of the application, the different aliphatic and / or aromatic polyisocyanates also have different chain lengths. In this case, the long-chain polyisocyanates preferably have 6, 7, 8, 9, 10, 11, 12, 13, 14, 20, 25 or more carbon atoms, but more preferably from 6 to 12 carbon atoms, particularly preferably from 6 to 8 carbon atoms. Short-chain polyisocyanates are understood to mean polyisocyanates having from 1 to 5 carbon atoms, preferably from 3 to 5 carbon atoms.

[0112] Preferred according to the application is a combination of short-chain aliphatic polyisocyanates (C1, C2, C3, C4, C5) and long-chain aliphatic polyisocyanates (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more), or a combination of short-chain aliphatic polyisocyanates (C1, C2, C3, C4, C5) (C1, C2, C3, C4, C5) and long-chain aromatic polyisocyanates (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more), or a combination of long-chain aliphatic polyisocyanates (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more) (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more) and short-chain aromatic polyisocyanates.

[0113] In this regard, it is particularly preferred to use a mixture of different aliphatic polyisocyanates having two or more isocyanate groups with a chain length of from 1 to 12 carbon atoms in the chain, preferably from 3 to 8 carbon atoms, particularly preferably from 4 to 7 carbon atoms, to prepare the biodegradable microcapsules according to the application.

[0114] In this regard, aliphatic polyisocyanates are particularly preferred due to their chemical relationship to bio-based systems. For example, lysine and 1,5-diisocyanopentane both show the same degradation product 1,5-diaminopentane and are therefore considered particularly suitable for the production of bio-based and biodegradable microcapsules with regard to environmental aspects.

[0115] Main embodiments include mixtures of long-chain and short-chain diisocyanates in any ratio. Preferably, the mixing ratio of long-chain diisocyanates to short-chain diisocyanates is in the range of 4:1 to 1 :4, particularly preferably in the range of 2:1 to 1 :2.

[0116] Examples of preferred specific mixtures of at least one aliphatic polyisocyanate and at least one aromatic polyisocyanate are mixtures of hexamethylene diisocyanate biuret with toluene diisocyanate trihydroxymethyl adduct, mixtures of hexamethylene diisocyanate biuret with diisocyanate polyisocyanate, or mixtures of hexamethylene diisocyanate biuret with toluene diisocyanate trihydroxymethyl propane adduct.

[0117] According to the present application, it is more preferred if in the combination of short-chain aliphatic polyisocyanates and long-chain aliphatic polyisocyanates as described before, or in the combination of short-chain aliphatic polyisocyanates and long-chain aromatic polyisocyanates, or in the combination of long-chain aliphatic polyisocyanates and short-chain aromatic polyisocyanates, the polyisocyanates are present in a mixture of monomeric or oligomeric or polymeric form.

[0118] Preferably, for use in the process according to the present application, the following combinations result from this:

[0119] - short-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and short-chain aliphatic polyisocyanate (monomer or oligomer or polymer);

[0120] - short-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and long-chain aliphatic polyisocyanate (monomer or oligomer or polymer);

[0121] - short-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and short-chain aromatic polyisocyanate (monomer or oligomer or polymer);

[0122] - short-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and long-chain aromatic polyisocyanate (monomer or oligomer or polymer);

[0123] - long-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and short-chain aliphatic polyisocyanate (monomer or oligomer or polymer);

[0124] - long chain aliphatic polyisocyanate (monomer or oligomer or polymer) and long chain aliphatic polyisocyanate (monomer or oligomer or polymer);

[0125] - long chain aliphatic polyisocyanate (monomer or oligomer or polymer) and short chain aromatic polyisocyanate (monomer or oligomer or polymer);

[0126] - long chain aliphatic polyisocyanate (monomer) and long chain aromatic polyisocyanate (oligomer or polymer);

[0127] as well as the definitions of short chain and long chain described before.

[0128] It can be observed that due to the different reaction rates of the polyisocyanate components, the different dissociation and crosslinking structures, the selection of at least two different chain lengths and polymerization degrees of aliphatic polyisocyanates, or the selection of a mixture of aliphatic and aromatic polyisocyanates, can significantly improve the stability and performance (release of the perfume in the case of perfume capsules).

[0129] The polyisocyanate combinations described above or polyisocyanate mixtures consisting of two different aliphatic or one aliphatic and one aromatic polyisocyanate can be used to produce particularly stable and better, i.e. more densely branched, crosslinks within the capsule shell.

[0130] Thus, using the methods described herein, high performance (perfume release) microcapsules made from a mixture of aliphatic and aromatic polyisocyanates or from a mixture of two different aliphatic polyisocyanates can be prepared. Such microcapsules are very stable and characterized by outstanding perfume retention properties, which in turn reflect in better performance (perfume release) of the capsules, e.g. in the field of perfume encapsulation.

[0131] Microcapsules produced using two different polyisocyanates again exceed the stability of microcapsules made from a single polyisocyanate system, as shown in the following examples.

[0132] Microcapsules made from aliphatic-aliphatic polyisocyanate mixtures are as good as microcapsules made from aliphatic-aromatic polyisocyanate mixtures, as demonstrated in the following examples. Thus, in principle, a combination of at least two different polymerizable (preferably aliphatic and / or aromatic) polyisocyanates is preferred in the present application.

[0133] The polyisocyanate used for the preparation of the microcapsules according to the present application is contained in an amount of 0.1 to 10.0 wt.-%, preferably 0.5 to 3.0 wt.-%, relative to the total weight of the internal non-aqueous phase.

[0134] The ratio of the polyisocyanate component to the internal non-aqueous phase is preferably between 1 :50 and 1 :20, even more preferably between 1 :40 and 1 :30.

[0135] According to the present application, due to the low content of the polyisocyanate component, it is possible to produce polyurea / polyurethane microcapsules in which the absolute content of polyisocyanate is only 1 / 50 of the entire capsule, which comprises at least one lipophilic active substance to be encapsulated. Thus, it is possible to produce polyurea / polyurethane microcapsules with a polyisocyanate content of only 0.6 wt.-%, relative to the total weight of the capsule wall, using the process according to the present application. Preferably, the polyisocyanate proportion is about 1.8 wt.-% of the capsule wall. Despite the low polyisocyanate content, the microcapsules according to the present application still stand out with high stability.

[0136] In step (a1 ) of the process according to the present application for producing microcapsules, at least one polymerizable polyisocyanate comprising at least two or more isocyanate functional groups is first dissolved together with at least one or more active substances to be encapsulated in an inert non-aqueous solvent or a solvent mixture of inert non-aqueous solvents. By "substantially dissolved" is meant that at least 90 wt.-%, preferably at least 98 wt.-%, even more preferably 99.9 wt.-% of the above-mentioned ingredients are dissolved in the solvent or solvent mixture in order to be able to use them in the present process. More preferably, the at least one polyisocyanate and the at least one active substance to be encapsulated are completely dissolved in the solvent or solvent mixture. If the solvent does not guarantee sufficient solubility of the isocyanate, it is possible to overcome this disadvantage by using suitable solubility promoters.

[0137] The preferred solvents for the internal non-aqueous phase are not miscible with water, do not react with the isocyanate component or the active substances, and have little or no odor in the amounts used.

[0138] The term "solvent" in connection with the present application includes all types of oil bodies or oil components, in particular vegetable oils (such as rapeseed oil, sunflower oil, soybean oil and olive oil, and the like), modified vegetable oils (such as alkoxylated sunflower oil or soybean oil), synthetic glycerol (tri)esters (such as engineered mixtures of glycerol monoesters, diesters and triglycerides of C6 to C22 fatty acids), fatty acid alkyl esters (such as methyl or ethyl esters of vegetable oils (e.g. methyl or ethyl esters of sunflower oil or soybean oil), and the like. ME 18RD-F, ME 18SD-F, ME 12C-F and ME1270), fatty acid alkyl esters based on these C6 to C22 fatty acids), mineral oils and mixtures thereof. Examples of suitable and preferred lipophilic solvents are: Guerbet alcohols based on fatty alcohols having 6 to 18, preferably 8 to 10 carbon atoms, esters of linear C6 to C22 fatty acids with linear or branched C6 to C22 fatty alcohols or esters of branched C6 to C13 carboxylic acids with linear or branched C6 to C22 fatty alcohols, such as, for example, myristyl myristate, myristyl palmitate, myristyl stearate, myristyl isostearate, myristyl oleate, myristyl behenate, myristyl erucate, cetyl myristate, cetyl palmitate, cetyl stearate, cetyl isostearate, cetyl oleate, cetyl behenate, cetyl erucate, stearyl myristate, stearyl palmitate, stearyl stearate, stearyl isostearate, stearyl oleate, stearyl behenate, stearyl erucate, isostearyl myristate, isostearyl palmitate, isostearyl stearate, isostearyl isostearate, isostearyl oleate, isostearyl behenate, isostearyl erucate, oleyl myristate, oleyl palmitate, oleyl stearate, oleyl isostearate, oleyl oleate, oleyl behenate, oleyl erucate, behenyl myristate, behenyl palmitate, behenyl stearate, behenyl isostearate, behenyl oleate, behenyl behenate, behenyl erucate, erucyl myristate, erucyl palmitate, erucyl stearate, erucyl isostearate, erucyl oleate, erucyl behenate and erucyl erucate.

[0139] Also suitable are esters of linear C6 to C22 fatty acids with branched alcohols, in particular 2-ethylhexanol, esters of C18 to C38 alkylhydroxycarboxylic acids with C6 to C22 linear or branched fatty acids, in particular dioctyl acid esters, esters of linear or branched fatty acids with polyhydric alcohols, such as, for example, propylene glycol, dipolyglycol or tripolyglycol, and / or Guerbet alcohols, triglycerides based on C6 to C10 fatty acids, liquid glycerol monoester / diester / triester mixtures of C6 to C18 fatty acids, esters of C6 to C22 fatty alcohols and / or Guerbet alcohols with aromatic carboxylic acids, in particular benzoic acid, esters of C2 to C12 dicarboxylic acids with linear or branched alcohols having 1 to 22 carbon atoms or with polyhydric alcohols having 2 to 10 carbon atoms and 2 to 6 hydroxyl groups, vegetable oils, branched primary alcohols, substituted cyclohexanes, linear or branched C6 to C22 fatty alcohol carbonates, such as, for example, dicaprylyl carbonate (Finsolv® CC), Guerbet carbonates based on fatty alcohols having 6 to 18, preferably 8 to 10 carbon atoms, benzoic acid esters with linear or branched C6 to C22 alcohols, linear or branched, symmetrical or asymmetrical dialkyl ethers, such as, for example, dicaprylyl ether, ring-opening products of epoxidized fatty acid esters with polyhydric alcohols, silicone oils (cyclic polymethylsiloxanes, polysiloxanes of the dimethicone grade aliphatic or cycloparaffinic hydrocarbons, such as squalane, squalene or dialkylcyclohexane and / or mineral oil.

[0140] In particular, preferred solvents are esters of linear C6to C22fatty acids with branched alcohols, esters of C18to C38alkylhydroxy carboxylic acids with C6to C22linear or branched alcohols, esters of linear or branched C6to C22fatty alcohols, in particular dioctyl malate, esters of linear or branched C6to C22fatty acids with polyhydric alcohols, such as propylene glycol, dipolyglycol or tripolyglycol and / or esters of Guerbet alcohols, triglycerides based on C6to C10fatty acids, liquid glycerol mono- / di- / triesters mixtures based on C6to C18fatty acids, esters of C6to C22fatty alcohols and / or Guerbet alcohols with aromatic carboxylic acids, in particular benzoic acid, esters of C2to C12dicarboxylic acids with linear or branched alcohols having 1 to 22 carbon atoms or polyhydric alcohols having 2 to 10 carbon atoms and 2 to 6 hydroxyl groups, vegetable oils, branched primary alcohols, substituted cyclohexanes, linear or branched C6to C22fatty alcohol carbonates, such as dicaprylyl carbonate (Cetiol™ CC), Guerbet carbonates based on 6 to 18, preferably 8 to 10 carbon atoms of fatty alcohols, esters of benzoic acid with linear or branched C6to C22alcohols, linear or branched, symmetrical or asymmetrical dialkyl ethers, such as dicaprylyl ether (Cetiol™ OE), ring-opening products of epoxidized fatty acid esters with polyhydric alcohols, silicone oils (cyclic polymethylsiloxanes and Siliciummethicon-Typen and the like) and / or aliphatic or cycloparaffinic hydrocarbons, such as squalane, squalene or dialkylcyclohexane and / or mineral oil.

[0141] Furthermore, within the scope of the present application, liquid linear and / or branched and / or saturated or unsaturated hydrocarbons or any desired mixtures thereof can be used as solvents. These can be, for example, alkanes having 4 to 22 carbon atoms, preferably 6 to 18 carbon atoms, or any mixtures thereof.

[0142] Alkylarenes such as diisopropyl naphthalene or substituted diphenyls, chlorinated diphenyls, paraffins, chlorinated paraffins, natural vegetable oils such as cottonseed oil, peanut oil and palm oil, trimethylphenyl phosphite, silicone oils, dialkyl phthalates, dialkyl adipates, partially hydrogenated terphenyls, alkylated diphenyls, alkylated naphthalenes, diaryl ethers, arylalkyl ethers and highly alkylated benzenes, benzyl benzoate, isopropyl myristate and also any mixtures of these hydrophobic solvents and mixtures of one or more of these hydrophobic solvents with kerosene, paraffins and / or isoparaffins are particularly suitable as inert solvents for the internal non-aqueous phase. Preferably, vegetable oils such as sunflower oil, triglycerides, benzyl benzoate or isopropyl myristate are used as solvents for providing the internal non-aqueous phase.

[0143] The solvents described above are used either alone or as a mixture of two or more solvents in the method according to the invention.

[0144] In alternative and preferred variations of the method according to the invention, at least one polyisocyanate is directly dissolved in a solution of at least one active substance, preferably one or more flavorings or seasonings / fragrances or seasonings or aromatic oils, so that the aforementioned solvent is substantially absent in the core of the microcapsule according to the invention. In this regard, avoiding the use of solvents in the microcapsule core is advantageous because it reduces manufacturing costs and takes environmental factors into account.

[0145] Fragrances or flavorings are specifically dissolved in solvents commonly used in the perfume or flavoring industry. The solvent is preferably not an alcohol, as alcohols interact with isocyanates. Examples of suitable solvents include diethyl phthalate, isopropyl myristate, etc. (Rosin resin, available from Eastman), benzyl benzoate, ethyl citrate, limonene, or other terpenes or isoalkanes. Preferably, the solvent is highly hydrophobic. Preferably, the flavoring or seasoning solution contains less than 30% solvent. More preferably, the flavoring or seasoning solution comprises less than 20% solvent, even more preferably less than 10% solvent, wherein all these percentages are defined by weight relative to the total weight of the flavoring or seasoning solution. Most preferably, the flavoring or seasoning is substantially solvent-free.

[0146] As the active material or core material to be encapsulated in the manufacture of microcapsules according to the invention, virtually any material suitable for encapsulation in the microcapsules can be considered. The material to be encapsulated is a lipophilic, water-insoluble or sparingly water-soluble liquid or solid, or suspension. This ensures that, during the preparation of the microcapsules according to the invention, the active material to be encapsulated is in the internal non-aqueous phase and does not mix with the external aqueous phase, because otherwise an emulsion cannot be formed and the capsule wall material cannot be deposited on the droplet surface. This results in the lipophilic active material being completely encapsulated as the core material within the microcapsule during subsequent emulsification and cross-linking of the capsule wall components. The internal non-aqueous phase thus formed is characterized by its organic hydrophobic and oily properties.

[0147] In a particularly preferred variant of the application, the at least one lipophilic or hydrophobic active substance is in particular a lipophilic or hydrophobic perfume or flavour, or a lipophilic or hydrophobic fragrance oil or flavour (perfume or flavour mixture), a cooling agent, a TRPV1 or TRPV3 modulator, a substance which causes a pungent taste or heat or a hot sensation on the skin or mucous membranes, or a substance which causes a stinging or a tingling sensation in the mouth or throat, or an active substance which has an irritant or stinging or astringent effect, a pesticide, a biocide, a sterilising agent, a substance from the group of repellents, a food additive, a cosmetic active substance, a pharmaceutical active substance, a dye, a dye precursor, a luminescent ink, an agrochemical, an optical whitener, a solvent, a wax, a silicone oil, a lubricant, a paper printing-plate coating material, or a mixture of two or more active substances mentioned above.

[0148] In a preferred variant of the application, in particular a lipophilic perfume or a perfume mixture consisting of two or more perfumes (fragrance oils), or a perfume consisting of two or more perfumes (flavours) or a perfume mixture consisting of two or more perfumes (flavours (Aromen)), or even biogenic substances, are considered to be lipophilic active substances.

[0149] Particularly preferably, the core comprises one or more perfumes or flavours selected from the group consisting of extracts of natural raw materials and fractions or constituents isolated therefrom; individual perfumes from the group of hydrocarbons; fatty alcohols; fatty aldehydes and acetales; fatty ketones and oximes; fatty sulfur compounds; fatty nitriles; fatty carboxylic acid esters; formic, acetic, propionic, isobutyric, butyric, isovaleric, valeric, caproic, crotonic, tiglic and 3-methyl-2-butenoic acid esters of acyclic terpene alcohols; acyclic terpene aldehydes and ketones and their dimethyl and diethyl acetales; formic, acetic, propionic, isobutyric, butyric, isovaleric, valeric, caproic, crotonic, tiglic and 3-methyl-2-butenoic acid esters of cyclic terpene alcohols; cyclic terpene aldehydes and ketones; cyclic alcohols; cyclic ethers and alicyclic ethers; cyclic ketones and macrocyclic ketones; alicyclic aldehydes; alicyclic ketones; cyclic alcohol esters; esters of alicyclic alcohols; esters of alicyclic carboxylic acids; aromatic hydrocarbons; araliphatic alcohols; esters of araliphatic alcohols and fatty carboxylic acids; araliphatic ethers; aromatic and araliphatic aldehydes; aromatic and araliphatic ketones; aromatic and araliphatic carboxylic acids and their esters; nitrogen-containing aromatic compounds; benzene ethers and esters; heterocyclic compounds; lactones and mixtures of the active substances mentioned above, wherein the shell is completely or essentially impermeable to the perfume.

[0150] Suitable fragrances and flavors for the manufacture of the capsules according to the application are preferably described in Steffen Arctander, "Riechstoffe [Fragrances]", Eigenverlag, Montclair, N.J. 1969; H. Surburg, J. Panten, "Perfume and Flavor Chemicals", 5th edition, Wiley-VCH, Weinheim 2006; "Common Fragrance and Flavor Materials", 5th edition, Wiley-VCH, Weinheim 2006.

[0151] Preferably, the microcapsules according to the application have a core material in the form of a hydrophobic single fragrance or single flavor, wherein the core material comprises at least one single fragrance or single flavor selected from one or more groups of the following groups:

[0152] - hydrocarbons, such as 3-carene; alpha-pinene; beta-pinene; alpha-terpinene; gamma-terpinene; p-cymene; bisabolene; camphene; caryophyllene; cedrene; farnesene; limonene; longifolene; myrcene; ocimene; valencene; (E,Z)-1,3,5-undecatriene; styrene; diphenylmethane;

[0153] - fatty alcohols, such as hexanol; octanol; 3-octanol; 2,6-dimethylheptanol; 2- methylheptanol; 2-methyloctanol; (E)-2-hexenol; (E) and (Z)-3-hexenol; 1 -octen-3- ol; mixture of 3,4,5,6,6-pentamethyl-3,4-hepten-2-ol and 3,5,6,6-tetramethyl-4- methyleneheptan-2-ol; (E,Z)-2,6-nonadienol; 3,7-dimethyl-7-methyloctan-2-ol; 9- decenol; 10-undecenol; 4-methyl-3-decen-5-ol;

[0154] - fatty aldehydes and their acetales, such as hexanal; heptanal; octanal; nonanal; decanal; undecanal; dodecanal; tridecanal; 2-methyloctanal; 2-methylnonanal; (E)-2- hexenal; (Z)-4-heptenal; 2,6-dimethyl-5-heptenal; 10-undecenal; (E)-4-decenal; 2- dodecenal; 2,6,10-trimethyl-5,9-undecadienal; heptanal diethyl acetal; 1,1 -dimethoxy- 2,2,5-trimethyl-4-hexene; citronellyloxyacetaldehyde; 1 -(1 -methoxy-propoxy)-(E / Z)-3- hexene;

[0155] - fatty ketones and oximes thereof, such as 2-heptanone; 2-octanone; 3-octanone; 2-nonanone; 5-methyl-3-heptanone; 5-methyl-3-heptanone oxime; 2,4,4,7-tetramethyl-6- octen-3-one; 6-methyl-5-hepten-2-one;

[0156] - fatty sulfur compounds, such as 3-methylthio-hexanol; 3-methylthio-hexyl acetate; 3- mercapto-hexanol; 3-mercapto-hexyl acetate; 3-mercapto-hexyl butyrate; 3-acetylthio- hexyl acetate; 1 -menthene-8-thiol;

[0157] - fatty nitriles, such as 2-nonenitrile; 2-tridecenitrile; 2,12-tridecenitrile; 3,7-dimethyl-2,6- octadienenitrile; 3,7-dimethyl-6-octenenitrile;

[0158] - fatty carboxylic acids and esters thereof, such as (E)- and (Z)-3-hexenyl formate; ethyl acetoacetate; isoamyl acetate; hexyl acetate; 3,5,5-trimethylhexyl acetate; 3-methyl-2-butenyl acetate; (E)-2-hexenyl acetate; (E) and (Z)-3-hexenyl acetate; octyl acetate; 3-octyl acetate; 1-octen-3-yl acetate; ethyl butyrate; butyl butyrate; isoamyl butyrate; hexyl butyrate; (E) and (Z)-3-hexenyl isobutyrate; hexyl crotonate; ethyl isovalerate; ethyl 2-methylvalerate; ethyl hexanoate; allyl hexanoate; ethyl heptanoate; allyl heptanoate; ethyl octanoate; (E,Z)-2,4-decadienoic acid ethyl ester; in particular 2-trans-4-cis-decadienoic acid ethyl ester; 2-octanol methyl ester; 2-nonanoic acid methyl ester; 2-isopentyloxyallyl acetate; 3,7-dimethyl-2,6-octadienoic acid methyl ester; 4-methyl-2-pentyl crotonate;

[0159] - acyclic terpene alcohols, such as citronellol; geraniol; nerol; linalool; lavandulol; nerolidol; farnesol; tetrahydrolinalool; tetrahydrogeraniol; 2,6-dimethyl-7-octen-2-ol; 2,6-dimethyloctan-2-ol; 2-methyl-6-methylene-7-octen-2-ol; 2,6-dimethyl-5,7-octadien-2-ol; 2,6-dimethyl-3,5-octadien-2-ol; 3,7-dimethyl-4,6-octadien-3-ol; 3,7-dimethyl-1,5,7-octatrien-3-ol; 2,6-dimethyl-2,5,7-octatrien-1 -ol; and formates, acetates, propionates, isobutyrates, butyrates, isovalerates, valerates, hexanoates, crotonates, tiglinates and 3-methyl-2-butenoates thereof;

[0160] - acyclic terpene aldehydes and ketones, such as geranial; neral; citronellal; 7-hydroxy-3,7-dimethyloctanal; 7-methoxy-3,7-dimethyloctanal; 2,6,10-trimethyl-9-undecenal; geranylacetone; and dimethyl and diethyl acetal of geranial, neral, 7-hydroxy-3,7-dimethyloctanal; in particular dimethyl and diethyl acetal of geranial, neral, 7-hydroxy-3,7-dimethyloctanal;

[0161] - cyclic terpene alcohols, such as menthol; isopulegol; alpha-terpineol; terpinen-4-ol; menthan-8-ol; menthan-1-ol; menthan-7-ol; borneol; isoborneol; linalool oxide; nootkatol; cedrol; ambratal; vetiverol; guaiacol; and formates, acetates, propionates, isobutyrates, butyrates, isovalerates, valerates, hexanoates, crotonates, tartrates and 3-methyl-2-butenoates thereof;

[0162] - cyclic terpene aldehydes and ketones, such as menthone; isomenthone; 8- mercaptomenthan-3-on; carvone; campher; fenchon; alpha-ionone; beta-ionone; alpha-n-methylionone; beta-n-methylionone; alpha-isomethylionone; beta-isomethylionone; alpha-irisone; beta-irisone; alpha-damascenone; beta-damascenone; gamma-damascenone; delta-damascenone; gamma-damascenone; 1 -(2,4,4-trimethyl-2-cyclohexen-1 -yl)-2-buten-1 -one; 1,3,4,6,7,8a-hexahydro-1,1,5,5-tetramethyl-2H-2,4a-epoxynaphthalen-8-(5H)-one; 2-methyl-4-(2,6,6-trimethyl-1 -cyclohexen-1 -yl)-2-butenal; norcaronal; dihydronodakenone; 4,6,8-metgastigmatrien-3-one; alpha-sinensal; beta-sinensal; acetylated cedarwood oil (methylcedrylketon); (Methylcedrylketon));

[0163] - cycloalcohols such as 4-tert-butylcyclohexanol; 3,3,5-trimethylcyclohexanol; 3- isopropylcyclohexanol; 2,6,9-trimethyl-(Z2,Z5,E9)-cyclododecatrien-1-ol; 2- isobutyl-4-methyltetrahydro-2H-pyran-4-ol; alicyclic alcohol groups such as 3,3,3- trimethylcyclohexylmethanol; 2-methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)butanol; 2-methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)-2-buten-1-ol; 2-ethyl-4-(2,2,3- trimethyl-3-cyclopent-1-yl)-2-buten-1-ol; 3-methyl-5-(2,2,3-trimethyl-3-cyclopent-1- yl)-pentan-2-ol; 3-methyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol; 3,3- dimethyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol; 1-(2,2,6-trimethylcyclohexyl) pentan-3-ol; 1-(2,2,6-trimethylcyclohexyl)hexan-3-ol;

[0164] - cycloalcohols such as 4-tert-butylcyclohexanol; 3,3,5-trimethylcyclohexanol; 3- isopropylcyclohexanol; 2,6,9-trimethyl-(Z2,Z5,E9)-cyclododecatrien-1-ol; 2- isobutyl-4-methyltetrahydro-2H-pyran-4-ol; alicyclic alcohol groups such as 3,3,3- trimethylcyclohexylmethanol; 2-methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)butanol; 2-methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)-2-buten-1-ol; 2-ethyl-4-(2,2,3- trimethyl-3-cyclopent-1-yl)-2-buten-1-ol; 3-methyl-5-(2,2,3-trimethyl-3-cyclopent-1- yl)-pentan-2-ol; 3-methyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol; 3,3- dimethyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol; 1-(2,2,6-trimethylcyclohexyl) pentan-3-ol; 1-(2,2,6-trimethylcyclohexyl)hexan-3-ol;

[0165] - cycloalcohols such as 4-tert-butylcyclohexanol; 3,3,5-trimethylcyclohexanol; 3- isopropylcyclohexanol; 2,6,9-trimethyl-(Z2,Z5,E9)-cyclododecatrien-1-ol; 2- isobutyl-4-methyltetrahydro-2H-pyran-4-ol; alicyclic alcohol groups such as 3,3,3- trimethylcyclohexylmethanol; 2-methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)butanol; 2-methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)-2-buten-1-ol; 2-ethyl-4-(2,2,3- trimethyl-3-cyclopent-1-yl)-2-buten-1-ol; 3-methyl-5-(2,2,3-trimethyl-3-cyclopent-1- yl)-pentan-2-ol; 3-methyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol; 3,3- dimethyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol; 1-(2,2,6-trimethylcyclohexyl) pentan-3-ol; 1-(2,2,6-trimethylcyclohexyl)hexan-3-ol;

[0166] - cycloaliphatic aldehydes such as 2,4-dimethyl-3-cyclohexenecarboxaldehyde; 2-methyl-4-(2,2,6-trimethyl-cyclohexen-1-yl)-2-butenal; 4-(4-hydroxy-4-methylpentyl)-3- cyclohexenecarboxaldehyde; 4-(4-methyl-3-penten-1-yl)-3-cyclohexenecarboxaldehyde;

[0167] - cycloaliphatic ketones such as 1-(3,3-dimethylcyclohexyl)-4-penten-1-one; 2,2-dimethyl-1-(2,4-dimethyl-3-cyclohexen-1-yl)-1-1-propanone; 1-(5,5-dimethyl-2- cyclohexen-1-yl)-4-penten-1-one; 2,3,8,8-tetramethyl-1,2,3,4,5,6,7,8-octahydro-2- naphthalenyl methyl ketone; methyl-2,6,10-trimethyl-2,5,9-cyclododecatrienyl ketone; tert- butyl-(2,4-dimethyl-3-cyclohexen-1-yl) ketone;

[0168] - esters of cycloalcohols such as 2-tert-butylcyclohexyl acetate; 4-tert-butylcyclohexyl acetate; 2-tert-amylcyclohexyl acetate; 4-tert-amylcyclohexyl acetate; 3,3,5-trimethylcyclohexyl acetate; decahydro-2-naphthalenyl acetate; 2-cyclopentylcyclopentyl crotonate; 3-pentyltetrahydro-2H-pyran-4-acetate; decahydro-2,5,5,8a tetramethyl-2- naphthalenyl acetate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5- or -6-indenyl acetate; 4,7- methano-3a,4,5,6,7,7a-hexahydro-5- or -6-indenyl propionate; 4,7-methano-3a,4,5,6,7,7a- hexahydro-5- or -6-indenyl isobutyrate; 4,7-methano-octahydro-5- or -6-indenyl acetate;

[0169] - esters of cycloaliphatic alcohols such as 1-cyclohexylethyl crotonate;

[0170] - esters of cycloaliphatic carboxylic acids such as allyl-3-cyclohexyl propionate; allyl cyclohexyloxy acetate; cis and trans methyl dihydrojasmone; cis and trans jasmone methyl ester; 2- hexyl 3-oxocyclopentane carboxylic acid methyl ester; 2-ethyl-6,6-dimethyl-2-cyclohexene carboxylic acid ethyl ester; 2,3,6,6-tetramethyl-2-cyclohexene carboxylic acid ethyl ester; 2- methyl-1,3-dioxolane-2-acetic acid ethyl ester;

[0171] - aromatic hydrocarbons such as styrene and diphenylmethane;

[0172] - fatty alcohols, such as benzyl alcohol; 1-phenylethanol; 2-phenylethanol; 3-phenylpropanol; 2-phenylpropanol; 2-phenoxyethanol; 2,2-dimethyl-3-phenylpropanol; 2,2-dimethyl-3-(3-methylphenyl)propanol; 1,1-dimethyl-2-phenylethanol; 1,1-dimethyl-3-phenylpropanol; 1-ethyl-1-methyl-3-phenylpropanol; 2-methyl-5-phenylpentanol; 3-methyl-5-phenylpentanol; 3-phenyl-2-propen-1-ol; 4-methoxybenzyl alcohol; 1-(4-isopropylphenyl)ethanol;

[0173] - esters of aromatic aliphatic alcohols and fatty carboxylic acids, such as benzyl acetate; benzyl propionate; benzyl isobutyrate; benzyl isovalerate; 2-phenylethyl acetate; 2-phenylethyl propionate; 2-phenylethyl isobutyrate; 2-phenylethyl isovalerate; 1-phenylethyl acetate; benzyl a-trichloromethyl acetate; ethyl a,a-dimethylphenyl acetate; ethyl a,a-dimethylphenyl butyrate; cinnamyl acetate; 2-phenoxyisobutyl acetate; 4-methoxybenzyl acetate;

[0174] - aromatic aliphatic ethers, such as 2-phenylethyl methyl ether; 2-phenylethyl isopentyl ether; 2-phenylethyl-1-ethoxyethyl ether; phenylacetaldehyde dimethyl acetal; phenylacetaldehyde diethyl acetal; hydratropaaldehyde dimethyl acetal; phenylacetaldehyde glycerol acetal; 2,4,6-trimethyl-4-phenyl-1,3-dioxane; 4,4a,5,9b-tetrahydroindeno[1,2-d]dioxin; 4,4a,5,9b-tetrahydro-2,4-dimethylindeno[1,2-d]dioxin;

[0175] - aromatic and aromatic aliphatic aldehydes, such as benzaldehyde; phenylacetaldehyde; 3-phenylpropanal; hydratropaaldehyde; 4-methylbenzaldehyde; 4-methylphenylacetaldehyde; 3-(4-ethylphenyl)-2,2-dimethylpropanal; 2-methyl-3-(4-isopropylphenyl)propanal; 2-methyl-3-(4-tert-butylphenyl)propanal; 3-(4-tert-butylphenyl)propanal; cinnamaldehyde; a-butylcinnamaldehyde; a-amylcinnamaldehyde; a-hexylcinnamaldehyde; 3-methyl-5-phenylpentanal; 4-methoxybenzaldehyde; 4-hydroxy-3-methoxybenzaldehyde; 4-hydroxy-3-ethoxybenzaldehyde; 3,4-methylenedioxybenzaldehyde; 3,4-dimethoxybenzaldehyde; 2-methyl-3-(4-methoxyphenyl)propanal; 2-methyl-3-(4-methylenedioxyphenyl)propanal;

[0176] - aromatic and araliphatic ketones such as acetophenone; 4-methylacetophenone; 4- methoxyacetophenone; 4-tert-butyl-2,6-dimethylacetophenone; 4-phenyl-2-butanone; 4-(4- hydroxyphenyl)-2-butanone; 1 -(2-naphthyl)ethanone; benzophenone; 1,1,2,3,3,6- hexamethyl-5-indenyl methyl ketone; 6-tert-butyl-1,1 -dimethyl-4-indenyl methyl ketone; 1 - [2,3-dihydro-1,1,2,6-tetramethyl-3-(1 -methylethyl)-1 H-5-indenyl]ethanone; 5',6',7',8'- tetrahydro-3',5',5',6',8',8'-hexamethyl-2-acetonaphthone;

[0177] - aromatic and araliphatic carboxylic acids and their esters such as benzoic acid; phenylacetic acid; methyl benzoate; ethyl benzoate; hexyl benzoate; benzyl benzoate; methyl phenylacetate; ethyl phenylacetate; geranyl phenylacetate; phenethyl phenylacetate; methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenethyl cinnamate; cinnamyl cinnamate; allyl phenoxyacetate; methyl salicylate; isopentyl salicylate; hexyl salicylate; cyclohexyl salicylate; cis-3-hexenyl salicylate; benzyl salicylate; phenethyl salicylate; 2,4-dihydroxy-3,6-dimethylbenzoic acid methyl ester; ethyl 3-phenylglycidate; ethyl 3-methyl 3-phenylglycidate;

[0178] - nitrogen-containing aromatic compounds such as 2,4,6-trinitro-1,3-dimethyl-5-tert- butylbenzene; 3,5-dinitro-2,6-dimethyl-4-tert-butylacetophenone; cinnamic nitrile; 5-phenyl-3- methyl-2-pentanoic nitrile; 5-phenyl-3-methylpentanoic nitrile; methyl anthranilate; methyl N- methylanthranilate; Schiff bases of methyl anthranilate with 7-hydroxy-3,7-dimethyloctanal, 2- methyl-3-(4-tert-butyl-phenyl)propanal or 2,4-dimethyl-3-cyclohexenecarboxaldehyde; 6- isopropylquinoline; 6-isobutylquinoline; 6-sec-butylquinoline; indole; skatole; 2-methoxy-3- isopropylpyrazine; 2-isobutyl-3-methoxypyrazine; 4-(4,8-dimethyl-3,7-nonadienyl)pyridine;

[0179] - phenols, phenyl ethers and phenyl esters, such as Estragol [tarragol]; anethole; eugenol; eugenyl methyl ether; isoeugenol; isoeugenyl methyl ether; thymol; carvacrol; diphenyl ether; beta-naphthyl methyl ether; beta-naphthyl ethyl ether; beta-naphthyl isobutyl ether; 1,4-dimethoxybenzene; eugenyl acetate; 2-methoxy-4-methylphenol; 2-ethoxy-5-(1-propenyl)phenol; p-cresyl phenylacetate; groups from heterocyclic compounds, such as 2,5-dimethyl-4-hydroxy-2H-furan-3-one; 2-ethyl-4-hydroxy-5-methyl-2H-furan-3-one; 3-hydroxy-2-methyl-4H-pyran-4-one; 2-ethyl-3-hydroxy-4H-pyran-4-one;

[0180] - lactones, such as 1,4-octanolide; 3-methyl-1,4-octanolide; 1,4-nonanolide; 1,4-decanolide; 8-decen-1,4-olide; 1,4-undecanolide; 1,4-dodecanolide; 1,5-decanolide; 1,5-dodecanolide; 1,15-pentadecanolide; cis and trans 1 1-pentadecen-1,15-olide; cis and trans 12-pentadecen-1,15-olide; 1,16-hexadecanolide; 9-hexadecen-1,16-olide; 10-oxa-1,16-hexadecanolide; 1 1 -oxa-1,16-hexadecanolide; 12-oxa-1,16-hexadecanolide; ethylene-1,12-dodecanedioate; ethylene-1,13-tridecanedioate; coumarin; 2,3-dihydrocoumarin; octahydrocoumarin;

[0181] and stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers and / or epimers of the aforementioned substances and mixtures of the aforementioned substances.

[0182] In another variant of the process according to the application, the flavourings can also be encapsulated in the form of a core substance which comprises at least one single flavouring or mixtures thereof as active substance.

[0183] Typical examples of flavoring or fragrance agents that can be encapsulated within the meaning of the present application are selected from the group comprising: acetophenone; allyl hexanoate; alpha-ionone; beta-ionone; anisic aldehyde; anisic acid acetate; anisic acid formate; benzaldehyde; benzothiazole; benzyl acetate; benzyl alcohol; benzyl benzoate; beta-ionone; butyric acid butyl ester; butyric acid hexyl ester; butylidenephthalide; carvone; camphene; caryophyllene; cineol; cinnamic acid cinnamyl ester; citral; citronellol; citronellal; citronellyl acetate; cyclohexane acetic acid ester; cymene; damascone; decanolide; dihydrocoumarin; dimethyl anthranilate; dimethyl anthranilate; dodecalactone; ethoxyethyl acetate; ethyl butanoate; ethyl butyrate; ethyl decanoate; ethyl hexanoate; ethyl tiglate; ethyl furanone; ethyl guaiacol; ethyl isobutyrate; ethyl isovalerate; ethyl lactate; ethyl methyl butyrate; ethyl propionate; eucalyptol; eugenol; ethyl heptanoate; 4-(p-hydroxyphenyl)-2-butanone; gamma-decalactone; geraniol; geranyl acetate; geranyl acetate; grapefruit aldehyde; methyl dihydrojasmonate (e.g. ) ; Heliotropin; 2-Heptanone; 3-Heptanone; 4-Heptanone; trans-2-Heptenal; cis-4-Heptenal; trans-2-Hexenal; cis-3-Hexenol; trans-2-Hexenoic acid; trans-3-Hexenoic acid; cis-2-Hexenyl acetate; cis-3-Hexenyl acetate; cis-3-Hexenyl hexanoate; trans-2-Hexenyl hexanoate; cis-3-Hexenyl formate; cis-2-Hexyl acetate; cis-3-Hexyl acetate; trans-2-Hexyl acetate; cis-3-Hexyl formate; p-Hydroxybenzaldehyde; Isoamyl alcohol; Isoamyl isovalerate; Isobutyl butyrate; Isobutyraldehyde; Isobutyl p-menthyl ether; Isopropyl methyl thiazole; Lauric acid; Levulinic acid; Linalool; Linalool oxide; Linalyl acetate; Menthol; Menthofuran; Methyl anthranilate; Methyl butanol; Methyl butanoate; Methyl hexanoate; Methyl cinnamate; 5-Methylfurfural; 3,2,2-Methylcyclopentenolone; 6,5,2-Methylheptenone; Methyl dihydrojasmonate; Methyl jasmonate; 2-Methylbutyric acid; 2-Methyl-2-pentenoic acid; Methyl thiobutyrate; 3,1-Methylthiohexanol; 3-Methylthiohexyl acetate; Nerol; Nerilly acetate; Trans, trans-2,4-Nonadienal; 2,4-Nonadienol; 2,6-Nonadienol; 2,4-Nonadienol; Nootkatone; δ-Octalactone; γ-Octalactone; 2-Octanol; 3-Octanol; 1,3-Octenol; 1-Octanol acetate; 3-Octanol acetate; Palmitic acid; Paraldehyde; Phellandrene; Pentanedione; Phenethyl acetate; Phenethyl alcohol; Phenethyl alcohol; Phenethyl isovalerate; Piperonal; Propionaldehyde; Propyl butyrate; Pulegone; Pulegol; Sinensal; Sulfurol; Terpinene; Terpineol; Terpinolene; 8,3-Thiomenthanon; 4,4,2-Thiomethylpentanone; Thymol; δ-Undecalactone; γ-Undecalactone; Valencene; Valeric acid; Vanillin; Acetoin; Ethylvanillin; Ethylvanillin isobutyrat, 3-ethoxy-4-isobutyryloxybenzaldehyde; 2,5-Dimethyl-4-hydroxy-3(2H)-furanone and derivatives thereof (preferably cyclotene (2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone), homofuranone (2-ethyl-5-methyl-4-hydroxy-3(2H)-furanone and 5-ethyl-2-methyl-4-hydroxy-3(2H)-furanone); maltol and maltol derivatives (preferably ethyl maltol); coumarin and coumarin derivatives; gamma-lactones (preferably gamma-undecalactone, gamma-nonolactone, gamma-decalactone); delta-lactones (preferably 4-methyl delta-decalactone, massoia lactone, delta-decalactone, tuberolactone); methyl sorbate; dihydroguaiaretic acid; 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)furanone;2-hydroxy-3-methyl-2-cyclopenten-l-one; 3-hydroxy-4,5-dimethyl-2(5H)- furanone; isoamyl acetate; ethyl butyrate; n-butyl butyrate; isoamyl butyrate; ethyl 3-methylbutyrate; ethyl n-hexanoate; allyl n-hexanoate; n-butyl n-hexanoate; ethyl n-octanoate; ethyl 3-methyl-3-phenylglycidate; ethyl 2-trans-4-cis-decadienoate; 4-(p- hydroxyphenyl)-2-butanone; l,l-dimethoxy-2,2,5-trimethyl-4-hexanone; 2,6-dimethyl- 5-heptenal; phenylacetaldehyde; 2-methyl-3-(methylthio)furan; 2-methyl-3- furfuraldehyde; bis(2-methyl-3-furyl)disulfide; furfuryl mercaptan; methylthiopropanal; 2-acetyl-2-thiazoline; 3-mercapto-2-pentanone; 2,5-dimethyl-3- furfuraldehyde; 2,4,5-trimethylthiazole; 2-acetylthiazole; 2,4-dimethyl-5- ethylthiazole; 2-acetyl-l-pyrroline; 2-methyl-3-ethylpyrazine; 2-ethyl-3,5- dimethylpyrazine; 2-ethyl-3,6-dimethylpyrazine; 2,3-diethyl-5-methylpyrazine; 3- isopropyl-2-methoxy-pyrazine; 3-isobutyl-2-methoxy-pyrazine; 2-acetylpyrazine; 2- pentylpyridine; (E,E)-2,4-decadienal; (E,E)-2,4-nonenal; (E)-2-octenal; (E)-2- nonenal; 2-undecenal; 12-methyltridecanal; l-penten-3-one; 4-hydroxy-2,5-dimethyl- 3(2H)-furanone; guaiacol; 3-hydroxy-4,5-dimethyl-2(5H)-furanone; 3-hydroxy-4- methyl-5-ethyl-2(5H)-furanone; cinnamaldehyde; cinnamyl alcohol; methyl salicylate; isopiperitenol and stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers or epimers of the above mentioned substances not explicitly mentioned herein and mixtures of the above mentioned substances.

[0184] Among the above mentioned individual fragrances which can be encapsulated in the sense of the present application, preferably fragrances having an aldehyde, carboxylic acid or ester function are used.

[0185] The aldehyde fragrances, which also include the corresponding acetals, esters and lactones, can be classified into the following groups, i.e.

[0186] (i) aliphatic aldehydes and their acetals;

[0187] (ii) cycloaliphatic aldehydes;

[0188] (iii) aromatic or araliphatic aldehydes;

[0189] (iv) aliphatic, aromatic or araliphatic esters; and

[0190] (v) lactones;

[0191] and mixtures thereof.

[0192] The above-mentioned aldehydes, carboxylic acids or esters having an aldehyde, carboxylic acid or ester function and mixtures thereof are selected from one or more of the following groups:

[0193] - aliphatic aldehydes and their acetales, such as hexanal; heptanal; octanal; nonanal; decanal; undecanal; dodecanal; tridecanal; 2-methyloctanal; 2-methylnonanal; (E)-2-hexenal; (Z)-4-heptenal; 2,6-dimethyl-5-heptenal; 10-undecenal; (E)-4-decenal; 2-dodecenal; 2,6,10-trimethyl-5,9-undecadienal; heptanal diethyl acetal; 1,1 -dimethoxy-2,2,5-trimethyl-4-hexene; citronellyloxyacetaldehyde;

[0194] - alicyclic aldehydes, such as 2,4-dimethyl-3-cyclohexenecarboxaldehyde; 2-methyl-4-(2,2,6-trimethyl-cyclohexen-1-yl)-2-butenal; 4-(4-hydroxy-4-methylpentyl)-3- cyclohexenecarboxaldehyde; 4-(4-methyl-3-penten-1-yl)-3-cyclohexenecarboxaldehyde;

[0195] - aromatic and araliphatic aldehydes, such as benzaldehyde; phenylacetaldehyde; 3-phenylpropanal; hydroabietyl aldehyde; 4-methylbenzaldehyde; 4-methylphenylacetaldehyde; 3-(4-ethylphenyl)-2,2-dimethylpropanal; 2-methyl-3-(4-isopropylphenyl)- propanal; 2-methyl-3-(4-tert-butylphenyl)propanal; 3-(4-tert-butylphenyl)propanal; cinnamic aldehyde; a-butylcinnamic aldehyde; a-amylcinnamic aldehyde; a-hexylcinnamic aldehyde; 3-methyl-5-phenylpentanal; 4-methoxybenzaldehyde; 4-hydroxy-3-methoxybenzaldehyde; 4-hydroxy-3-ethoxybenzaldehyde; 3,4-methylenedioxybenzaldehyde; 3,4-dimethoxybenzaldehyde; 2-methyl-3-(4-methoxyphenyl)-propanal; 2-methyl-3-(4-methylenedioxyphenyl)-propanal;

[0196] - aliphatic carboxylic acid esters, such as (E)- and (Z)-3-hexenyl formate; ethyl acetoacetate; isoamyl acetate; hexyl acetate; 3,5,5-trimethylhexyl acetate; 3-methyl-2-butenyl acetate; (E)-2-hexenyl acetate; (E) and (Z)-3-hexenyl acetate; octyl acetate; 3-octyl acetate; 1-octen-3-yl acetate; ethyl butyrate; butyl butyrate; isoamyl butyrate; hexyl butyrate; (E) and (Z)-3-hexenyl isobutyrate; hexyl crotonate; ethyl isovalerate; ethyl 2-methylvalerate; ethyl hexanoate; allyl hexanoate; ethyl heptanoate; allyl heptanoate; ethyl octanoate; (E,Z)-2,4-decadienoate; 2-methyl octanoate; 2-methyl nonanoate; allyl 2-isopentyloxyacetate; methyl 3,7-dimethyl-2,6-octadienoate; - aliphatic carboxylic acid esters, such as (E)- and (Z)-3-hexenyl formate; ethyl acetoacetate; isoamyl acetate; hexyl acetate; 3,5,5-trimethylhexyl acetate; 3-methyl-2-butenyl acetate; (E)-2-hexenyl acetate; (E) and (Z)-3-hexenyl acetate; octyl acetate; 3-octyl acetate; 1-octen-3-yl acetate; ethyl butyrate; butyl butyrate; isoamyl butyrate; hexyl butyrate; (E) and (Z)-3-hexenyl isobutyrate; hexyl crotonate; ethyl isovalerate; ethyl 2-methylvalerate; ethyl hexanoate; allyl hexanoate; ethyl heptanoate; allyl heptanoate; ethyl octanoate; (E,Z)-2,4-decadienoate; 2-methyl octanoate; 2-methyl nonanoate; allyl 2-isopentyloxyacetate; methyl 3,7-dimethyl-2,6-octadienoate;

[0197] - esters of cyclic alcohols, such as 2-tert-butylcyclohexyl acetate; 4-tert- butylcyclohexyl acetate; 2-teri-amylcyclohexyl acetate; 4-teri-amylcyclohexyl acetate; decahydro-2-naphthalenyl acetate; 3-pentyltetrahydro-2H-pyran-4- yl acetate; decahydro-2,5,5,8a-tetramethyl-2-naphthalenyl acetate; 4,7- methano-3a,4,5,6,7,7a-hexahydro-5- or -6-indenyl acetate; 4,7-methano-3a,4,5,6,7,7a- hexahydro-5- or -6-indenyl propionate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5- or -6- indenyl isobutyrate; 4,7-methano-octahydro-5- or -6-indenyl acetate;

[0198] - esters of aromatic and aliphatic alcohols, such as benzyl acetate; benzyl propionate; benzyl isobutyrate; benzyl isoamyi; phenylethyl 2-acetate; phenylethyl 2- propionate; phenylethyl 2-isobutyrate; phenylethyl 2-isoamyi; phenylethyl 1- acetate; α-trichloromethylbenzyl acetate; α,α-dimethylphenylethyl acetate; α,α- dimethylphenylethyl butyrate; cinnamyl acetate; 2-phenoxyethyl isobutyrate; 4- methoxybenzyl acetate;

[0199] - esters of alicyclic carboxylic acids, such as allyl-3-cyclohexylpropionate; allyl cyclohexyloxyacetate; methyl dihydrojasmolate; methyl jasmolate; methyl 2-hexyl-3- oxocyclopentanecarboxylate; ethyl 2-ethyl-6,6-dimethyl-2-cyclohexenecarboxylate; ethyl 2,3,6,6-tetramethyl-2-cyclohexenecarboxylate; ethyl 2-methyl-1,3- dioxolan-2-acetate;

[0200] - aromatic and aliphatic carboxylic acid esters, such as methyl benzoate; ethyl benzoate; hexyl benzoate; benzyl benzoate; methyl phenylacetate; ethyl phenylacetate; geranyl phenylacetate; phenylethyl phenylacetate; methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenylethyl cinnamate; cinnamyl cinnamate; allyl phenoxyacetate; methyl salicylate; isoamyl salicylate; hexyl salicylate; cyclohexyl salicylate; cis-3-hexenyl salicylate; benzyl salicylate; phenylethyl salicylate; methyl 2,4-dihydroxy-3,6-dimethylbenzoate; ethyl 3-phenylglycidate; ethyl 3-methyl-3-phenylglycidate.

[0201] The following aldehydes, acetals, esters and lactones are listed with their trade names, which are particularly preferred as representatives of groups (i) to (v) in the method according to the application:

[0202] Aldehydes: 2-methylpentanal; aldehyde C12 MNAHM; aldehyde C4; aldehyde C5; aldehyde C6; aldehyde C7; aldehyde C8; aldehyde C9; aldehyde C10; aldehyde C11 ISO; aldehyde C11 MOA pure; undecanal C11; undecylenic aldehyde C11 (Aldehyde C 11 UNDEYLENIC); aldehyde C12; aldehyde C12 MNA; aldehyde C13; aldehyde madarine; amylcinnamic aldehyde alpha; anisic aldehyde-O; anisic aldehyde; natural benzaldehyde; bergamal; boron aldehyde; bourgenoal; camphor aldehyde; citral; citronellal HM; citronellyl oxyacetaldehyde; citrylal; citroylal E HM; pheoxyl acetaldehyde; pheoxyl acetaldehyde 50PCT PEMOSA; crotonaldehyde; cuminic aldehyde; cyclamen aldehyde; decadienal trans, trans-2,4, cis-4 decenal; trans-2 decenal; natural trans-2 decenal; trans-4 decenal; decanal-9,1; dodecenal 2,6; trans-2 dodecanal; dupical; 10% trioxa decenyl aldehyde-4,5-2; ethyl hexanal; floracryl; geranial; heliotropin; heliotropine; heptadienal trans, trans, 2-4; cis-4 heptenal; trans-2 heptenal; trans-2 hexenal; hexyl cinnamic aldehyde alpha; hyacinth aldehyde; hydroxycitronellal; intrelevenaldehyde spec.; isononyl aldehyde; isovaleraldehyde; lemonal H&R JS I; lilial; linolal; neolilial; majantal; mandrinol; madarine 10% TEC BHT; melonal; METHODY citronellal; methyl butanal; methyl cinnamic aldehyde alpha; methyl phenyl pentenal 4,2,2; methyl thio propionaldehyde-3; methyl tridecanal-12 10% VT; methyl-3-buten-2-al; methyl-5-phenyl-2-hexen-2-al; mugenal 50DPG; neocyclocitral; nonadienal; trans, cis-2,6; cis-6 nonenal; trans-2 nonenal; 3 / 060251; trans-2-pentenal; perillaldehyde; phenylacetaldehyde; phenylbutenal trans-2,2; phenylpropanal; PINO ACET ALDEHYDE; PROFRANESAL; propionaldehyde 2-(p-tolyl); propionaldehyde; PS-IRALDEIN XNEU; safranal; salicylaldehyde FG; SILVIAL; tetrahydro-ligroaldehyde; cis-veratraldehyde-2,2; p-tolualdehyde FG; tridecenal trans-2; triclofenal (TRIFERNAL); undecadienal-2,4; trans-2-undecenal; VERNAL ALDEHYDE; VERTOCITRAL; VERTOMUGAL; VERTIPRENAL; VETRAL ROH; natural cinnamaldehyde HM; acetales: FLOROPAL; heptanal diethyl acetal; nonadiene aldehyde diethyl acetal; OKOUMAL; phenylacetaldehyde glycerol acetal; phenylacetaldehyde dimethyl acetal; esters: jasminopyran; jasminyl ester; methyl dihydrojasmonate;

[0203] In another alternative embodiment, in the polyurea / polyurethane microcapsules according to the present application, a perfume mixture or a fragrance oil or a perfume mixture or a perfume is used as the active substance or core material to be encapsulated. These are compositions containing at least one perfume or flavoring agent, and can be used to manufacture such fragrance oils or flavoring agents. This composition, in particular a perfume mixture or a fragrance oil, preferably comprises two, three, four, five, six, seven, eight, nine, ten or more perfumes. The perfume mixture or fragrance oil is preferably selected from the group comprising: extracts from natural raw materials; essential oils, extracts, absolutes, Harze, resinoids, balsams, tinctures, such as ambergris tincture; amyris oil; angelica seed oil; angelica root oil; anise oil; perilla oil; valerian oil; basil oil; clubmoss absolute; bay oil; mugwort oil; benzoin resin; bergamot oil; beeswax absolute; birch tar oil; bitter almond oil; balm mint oil; pachouli oil; cabreuva oil; cade oil; calamus oil; camphor oil; cananga oil; cardamom oil; cascarilla oil; cinnamon oil; acacia absolute; castoreum absolute; cedar leaf oil; cedarwood oil; cistus oil; citronella oil; lemon oil; copaiba balsam; copaiba balsam oil; coriander oil; costus root oil; cypress oil; davana oil; dill weed oil; dill seed oil; eau de brouts absolute; oakmoss absolute; elemi oil; tarragon oil; eucalyptus citriodora oil; eucalyptus oil; fennel oil; spruce needle oil; fir needle oil; galbanum oil; galbanum resin; geranium oil; grapefruit oil; guaiac wood oil; guaiac balsam; guaiac balsam oil; helichrysum absolute; helichrysum oil; ginger oil; iris root absolute; iris root oil; jasmine absolute; calamus oil; chamomile blue oil; chamomile romana oil; carrot seed oil; carvi oil; pine needle oil; spearmint oil; caraway oil; labdanum oil; labdanum absolute; labdanum resin; lavandin absolute; lavandin oil; lavender absolute; lavender oil; lemon grass oil; lovage oil; distilled white lemon oil; expressed white lemon oil; linaloe oil; litsea cubeba oil; laurel oil; laurel leaf oil; mace oil; marjoram oil; mandarin oil; Massoi bark oil; mimosa absolute; musk grain oil; musk tincture; muscat sage oil; nutmeg seed oil; myrrh absolute; myrrh oil; myrtle oil; clove leaf oil; clove flower oil; neroli oil; olibanum absolute; olibanum oil; asarabacca root oil; orange flower absolute; orange oil; oregano oil; palmarosa oil; patchouli oil; perilla oil; peru balsam oil; parsley leaf oil; parsley seed oil; bitter orange leaf oil; peppermint oil; pepper oil; pimento oil; pine oil; poley oil; rose absolute; rosewood oil; rose oil; rosemary oil; Dalmatian sage oil; Spanish sage oil; sandalwood oil;Celery seed oil; Spicy lavender oil; Star anise oil; Storax; Tagetes oil; Fir needle oil; Tea tree oil; Turpentine oil; Thyme oil; Tolu balsam; Tonka bean absolute; Tuberose absolute; Vanilla extract; Violet leaf absolute; Verbena oil; Vetiver oil; Juniper berry oil; Wine yeast oil; Wormwood oil; Wintergreen oil; Ylang-ylang oil; Yerba-santa oil; Zedoary oil; Cinnamon leaf oil; Cinnamon bark oil and fractions thereof or ingredients isolated therefrom.

[0204] Exemplary cooling agents used as lipophilic active substances in the preparation of microcapsules according to the present application include one or more menthol and menthol derivatives (e.g. L-menthol, D-menthol, racemic menthol, isomenthol, neoisomenthol, neomenthol), menthyl ethers (e.g. (1-menthoxy)-2-propanediol, (1-menthoxy)-2-methyl-1,2-propanediol, 1-menthyl methyl ether), menthyl esters (e.g. menthyl formate, menthyl acetate, menthyl isobutyrate, menthyl lactate, L-menthyl L-lactate, L-menthyl D-lactate, (2-methoxy)menthyl acetate, (2-methoxyethoxy)menthyl acetate, menthyl pyroglutamate), menthyl carbonates (e.g. propylene glycol menthyl carbonate, ethylene glycol menthyl carbonate, glycerol menthyl carbonate or mixtures thereof), hemi-esters of menthol with dicarboxylic acids or derivatives thereof (e.g. monomenthyl succinate, monomenthyl glutarate, monomenthyl malonate, o-menthyl succinate-N,N-(dimethyl)amide, o-menthyl succinate amide), menthyl carboxylic acid amides (e.g. menthyl carboxylic acid N-ethylamide [WS3], N-alpha-(methane carbonyl)glycine ethyl ester [WS5], menthyl carboxylic acid N-(4-cyano-phenyl)amide, menthyl carboxylic acid N-(alkoxyalkyl)amide), menthone and menthone derivatives (e.g. L-menthone glycerol ketal), 2,3-dimethyl-2-(2-propyl)butyric acid derivatives (e.g. 2,3-dimethyl-2-(2-propyl)butyric acid-N-methylamide [WS23]), isopulegol or esters thereof (1-(-)isopulegol, 1-(-)isopulegol acetate), menthane derivatives (e.g. p-menthane 3,8-diol), verbenone or synthetic or natural mixtures containing verbenone, pyrrolidine derivatives of cycloalkyldione derivatives (e.g. 3-methyl)-2-(1-pyrrolidinyl)-2-cyclopenten-1-one) or tetrahydropyrimidin-2-ones (e.g. Icilin or related compounds described in WO 2004 / 026840). Other cooling agents are menthol (L-menthol, D-menthol, racemic menthol, isomenthol, neoisomenthol, neomenthol), L-menthyl methyl ether, menthyl formate, menthyl acetate, menthone, isopulegol, L-(-)-isopulegol acetate) and verbenone, which have a taste effect. Suitable cooling agents are well known in the art, for example described in US 2017 / 216802 (A1 ), US 2010 / 273887 (A1 ), EP 2033688 (A2) and EP 1958627 (A2).

[0205] In another variant, in the polyurea / polyurethane microcapsules according to the application, a TRPV1 or TRPV3 modulator is used as active substance or as core material to be encapsulated. TRPV1 and TRPV3 modulators are known in the prior art and relate to the transient receptor potential channel (TRP) channels of the vanilloid (TRPV) subfamily. TRPV1 modulators give a pungent taste and a sensation of heat associated with capsaicin and piperine to humans. The TRPV3 protein belongs to the family of non-selective cation channels that play a role in a variety of processes, including temperature sensing and vascular regulation. The TRPV3 channel is directly activated by a variety of natural compounds such as carvacrol, thymol and eugenol. Other monoterpenes that either cause a sensation of warmth or are cutaneous irritants can also open the channel. Monoterpenes also induce TRPV3 channel agonist-specific desensitization in a calcium-independent manner.

[0206] In another variant of the polyurea / polyurethane microcapsules according to the application, an active substance selected from the group consisting of substances that cause a pungent taste or a heat or a sensation of heat on the skin or mucous membranes, or substances that cause a stinging or a sensation of stinging in the mouth or throat, or substances that have an irritating or stinging or astringent effect, is used as active substance to be encapsulated or as core material.

[0207] The active substances that cause a heat or a burn are preferably selected from the group comprising: paprika, chili powder, red pepper extract, pepper extract, capsicum extract, ginger root extract, pimenta extract (Aframomum melegueta), spilanthes extract (Spilanthes acmella or Spilanthes oleracea), Japanese pepper extract (Zanthoxylum piperitum), zanthoxyli extract, galangal extract, water pepper extract (Polygonium hydropiper), capsaicinoids, in particular capsaicin, dihydrocapsaicin or vanillyl-namides; gingerols, in particular gingerol-[6], gingerol-[8] or gingerol-

[10] ; shogaols, in particular shogaol-[6], shogaol-[8], shogaol-

[10] ; paradols, in particular paradol-[6], paradol-[8] or paradol-

[10] ; dehydroshogaols, in particular dehydroshogaol-[6], dehydroshogaol-[8] or dehydroshogaol-

[10] ; piperine; piperine derivatives; 2-(4-hydroxy-3-methoxy-phenyl)acetic acid ethyl ester and 3-phenylpropyl-2-(4-hydroxy-3-methoxy-phenyl) acetate and mixtures thereof.

[0208] The active substances perceptible as pungent or stinging are preferably selected from the group comprising aromatic isothiocyanates, in particular phenylethyl isothiocyanate, allyl isothiocyanate, cyclopropyl isothiocyanate, butyl isothiocyanate, 3-methylthiopropyl isothiocyanate, 4-hydroxybenzyl isothiocyanate, 4-methoxybenzyl isothiocyanate and mixtures thereof.

[0209] Preferably, the active substance causing a tingling sensation is selected from the group consisting of 2E,4E-decadienoic acid-N-isobutylamide (trans-santalan), in particular as described in WO 2004 / 043906; 2E,4Z-decadienoic acid-N-isobutylamide (cis-santalan), in particular as described in WO 2004 / 000787; 2Z,4Z-decadienoic acid-N-isobutylamide; 2Z,4E-decadienoic acid-N-isobutylamide; 2E,4E-decadienoic acid-N-([2S]-2-methylbutyl)amide; 2E,4E-decadienoic acid-N-([2S]-2-methylbutyl)amide; 2E,4E-decadienoic acid-N-([2R]-2-methylbutyl)amide; 2E,4Z-decadienoic acid-N-(2-methylbutyl)amide; 2E,4E-decadienoic acid-N-piperidin (achilleamide); 2E,4E-decadienoic acid-N-piperidin (sarmentin); 2E-decenoic acid-N-isobutylamide; 3E-decenoic acid-N-isobutylamide; 3E-nonenoic acid-N-isobutylamide; 2E,6Z,8E-decatrienoic acid-N-isobutylamide (helicidamide); 2E,6Z,8E-decatrienoic acid-N-([2S]-2-methylbutyl)amide (homohelicidamide); 2E,6Z,8E-decatrienoic acid-N-([2R]-2-methylbutyl)amide; 2E-deceno 4-ic acid-N-isobutylamide; 2Z-deceno 4-ynic acid-N-isobutylamide; 2E,6Z,8E,10E-dodecetraenoic acid-N-(2-methylpropyl)amide (a-sanshoic acid); 2E,6Z,8E,10E-dodecetraenoic acid-N-(2-hydroxy-2-methylpropyl)amide (a-hydroxysanshoic acid); 2E,6E,8E,10E-dodecetraenoic acid-N-(2-hydroxy-2-methylpropyl)amide (g-hydroxysanshoic acid); 2E,4E,8Z,10E,12E-tetradeca-pentaenoic acid-N-(2-hydroxy-2-methylpropyl)amide (g-hydroxyisomethoxy-sanshoic acid); 2E,4E,8E,10E,12E-tetradeca-pentaenoic acid-N-(2-hydroxy-2-methylpropyl)amide (g-hydroxyisomethoxysanshoic acid); 2E,4E,8Z,10E,12E-tetradeca-pentaenoic acid-N-(2-methyl-2-propenyl)amide (g-dehydro-sanshoic acid); 2E,4E,8Z,10E,12E-tetradeca-pentaenoic acid-N-(2-methylpropyl)amide (g-sanshoic acid); 2E,4E,8Z,11Z-tetradeca-tetraenoic acid-N-(2-hydroxy-2-methylpropyl)amide (bungeanool); 2E,4E,8Z,11E-tetradeca-tetraenoic acid-N-(2-hydroxy-2-methylpropyl)amide (isobungeanool);2E,4E,8Z-tetradecatrienoic acid-N-(2-hydroxy-2-methylpropyl)amide (dihydroxy piperin) and 2E,4E-tetradecadienoic acid-N-(2-hydroxy-2-methylpropyl)amide (tetrahydroxy piperin) and mixtures thereof.

[0210] Preferably, the active substance having astringent effect is selected from the group consisting of catechins, in particular epicatechin, gallocatechin, epigallocatechin and their respective gallate esters, in particular epigallocatechin gallate or epicatechin gallate, oligomers thereof (proanthocyanidins, procyanidins, procyanirins, thearubigenins, theagallols) and their C- and O-glycosides; dihydroflavonols, such as dihydromyricetin, taxifolin and their C- and O-glycosides, flavonols, such as myricetin, quercetin and their C- and O-glycosides, such as quercitrin, rutin, gallate esters of carbohydrates, such as tannins, pentagalloyl glucose or reaction products thereof, such as ellagitannins, aluminum salts, such as alum and mixtures thereof. Exemplary heating agents used as lipophilic active substances in the preparation of the microcapsules according to the application include

[0211] In another variant of the process according to the application, the biosourced substance can also be encapsulated as core material, wherein the core material comprises at least one biosourced substance or mixtures thereof.

[0212] Biosourced substances mean active substances having biological activity, such as tocopherol, tocopherol acetate, tocopherol palmitate, ascorbic acid, carnotine, carnosine, caffeine, (deoxy)ribonucleic acid and its cleavage products, beta-glucans, retinol, bisabolol, allantoin, phytol, panthenol, AHA acids, amino acids, ceramides, pseudoceramides, essential oils, plant extracts and vitamin complexes.

[0213] In another variant of the process according to the application, substances for paper printing coatings are also used as active substances to be encapsulated or as core material, such as described in US 2800457 A, the relevant disclosure of which is incorporated by reference in its entirety into the present specification.

[0214] The content of the lipophilic active substance or mixture of lipophilic active substances used for the preparation of the microcapsules according to the application is 90.0 to 99.9 wt.-%, preferably 97.0 to 99.5 wt.-%, based on the total weight of the internal non-aqueous phase.

[0215] The ratio of the one or more active substances to the internal non-aqueous phase is preferably between 50:1 and 20:1, even more preferably between 40:1 and 30:1.

[0216] Thus, by the process according to the application, a high loading of active substance in the microcapsules according to the application can be achieved.

[0217] Furthermore, the first polymerization and / or crosslinking step (a) of the process according to the application comprises providing an external aqueous phase comprising at least one protective colloid and optionally an emulsifier (a2).

[0218] To this end, the protective colloid and the emulsifier, if necessary, are dissolved in the external aqueous phase, preferably in an aqueous solvent. Suitable solvents are water or a mixture of water and at least one organic solvent which is miscible with water. Suitable organic solvents include glycerol, 1,2-propanediol, 1,3-propanediol, ethylene glycol, diethylene glycol, triethylene glycol and other similar compounds. However, the solvent is preferably water.

[0219] The protective colloid is a polymeric system which prevents the agglomeration (agglomeration, coagulation and flocculation) of emulsified, suspended or dispersed components when suspended or dispersed. During solvation, the protective colloid binds a large amount of water and produces a high viscosity in the aqueous solution, depending on the concentration. In the preparation of oil-in-water emulsions, the protective colloid adheres to the primary particles with its hydrophobic part and attaches its polar, i.e. hydrophilic, molecular part to the aqueous phase. By this attachment at the interface, the protective colloid reduces the interfacial tension and prevents the agglomeration of the primary particles. In addition, the protective colloid stabilizes the emulsion, in this case promoting the formation of relatively small droplets and thus also the formation of the corresponding microcapsules.

[0220] Within the scope of the process according to the application, the protective colloid has, in addition to the above-mentioned properties, also emulsifying properties. In the case of protective colloids, such as carboxymethylcellulose, acid-modified starch, polyvinyl alcohol, ammonium derivatives of polyvinyl alcohol, polystyrene sulfonate, polyvinylpyrrolidone, polyvinyl acrylate, which have sufficient emulsifying properties, it is even possible to advantageously dispense with the use of an emulsifier in the process according to the application.

[0221] The protective colloid used in the process according to the application is selected from the group consisting of:

[0222] - diols, in particular ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, isomeric butanediols, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-dodecanediol, and

[0223] - polyols, preferably triols, in particular glycerol and its ethoxylated and propoxylated products, trimethylolpropane and its ethoxylated and propoxylated products, polyvinyl alcohol (PVOH) and its derivatives, in particular ammonium or sulfonate functionalized polyvinyl alcohol, polyphenols, preferably 1,3,5-trihydroxybenzene, polysaccharides, in particular glucose, starch or chemically, mechanically and / or enzymatically modified starch, cellulose derivatives, such as hydroxyethyl cellulose, in particular quaternized hydroxyethyl cellulose or carboxymethyl cellulose,

[0224] - polyvinylpyrrolidone, vinyl maleic acid copolymer, sodium lignosulfonate, maleic anhydride / styrene copolymer, ethylene / maleic anhydride copolymer, acid ester copolymers of ethylene oxide, propylene oxide and polyethoxysorbitol, sodium dodecyl sulfate,

[0225] - animal and vegetable polymers, in particular gum arabic (Senegal type and Seyal type), proteins, gelatin, olibanum resin, shellac, lignin, chitosan, saponins

[0226] and mixtures of the aforementioned compounds.

[0227] Preferably, the external aqueous phase comprises at least one protective colloid, which is selected from polyvinylpyrrolidone, polyvinyl alcohol and mixtures thereof. Polyvinylpyrrolidone is particularly preferred. Commercial standard polyvinylpyrrolidones have a molar mass in the range from about 2500 to 750000 g / mol. It is particularly preferred to use polyvinyl alcohol or its ammonium derivatives, 1,3,5-trihydroxybenzene or starch, in particular modified starch, or animal or vegetable polymers as protective colloid for the preparation of the microcapsules according to the application.

[0228] Starch, in particular modified starch, or animal or vegetable polymers are biodegradable natural substances. Thus, in combination with the polyisocyanates described herein, it is possible to provide biobased and biodegradable capsule shells with the present process. Thus, in the process according to the application, starch and animal and vegetable polymers also act as so-called bio-crosslinkers.

[0229] The starch used in the process according to the application is selected from the group comprising corn starch, potato starch, rye starch, wheat starch, barley starch, oat starch, rice starch, pea starch, tapioca starch and mixtures thereof.

[0230] The chemically modified starch is preferably an acid-modified starch, an alkali-modified starch, an oxidized starch, an acetylated starch, a succinylated starch or an octenyl succinylated starch.

[0231] According to the application, a combination of two or more different protective colloids can also be used for the preparation of the microcapsules according to the application.

[0232] It has been found to be particularly advantageous in the process according to the application when using a combination of one of the above-mentioned protective colloids and starch as further protective colloid in the external aqueous phase. Due to the large number of hydroxyl functions, such a combination stabilizes the emulsion and, on the other hand, promotes the reaction between protective colloid and polyisocyanate, wherein in the reaction of the protective colloid with the polyisocyanate the reaction equilibrium is pushed to the side of the product, i.e. the polyurethane. In addition, the large number of hydroxyl functions in the starch also enables a particularly pronounced crosslinking in space.

[0233] The above-mentioned protective colloids have different reaction rates with the isocyanate groups of at least one polyisocyanate depending on the number of functional groups and / or the size of the protective colloid. For example, due to its size, glycerol reacts faster with isocyanate groups than starch. Thus, by selecting the protective colloid, it is possible to control the crosslinking of the protective colloid with the isocyanate groups of the polyisocyanate.

[0234] A combination of glycerol with starch or modified starch or glycerol with quaternized hydroxyethylcellulose or gum arabic of the Seyal type has proven to be a particularly advantageous combination. This combination takes advantage of the properties of both protective colloids mentioned above: on the one hand the high reaction rate of glycerol and on the other hand the number of polymerizable functional groups of starch.

[0235] The protective colloid used in the process according to the application has a dual function, on the one hand as protective colloid, thus preventing the agglomeration of the emulsified, suspended or dispersed components, stabilizing the subsequently formed emulsion, facilitating the formation of small droplets and stabilizing the finally formed microcapsule dispersion.

[0236] On the other hand, due to the polymerizable nature, for example functional groups, in particular hydroxyl groups, the protective colloid crosslinks with at least one or more polyisocyanates during polymerization. By crosslinking with at least one polyisocyanate, a polymer layer has already been formed during the emulsification step (a3), which facilitates the formation of the capsule wall and becomes an integral part thereof.

[0237] It has surprisingly been found that, in the presence of a protective colloid, preferably a polyol, when an internal non-aqueous phase is emulsified or suspended in an external aqueous phase, a polymerization and / or crosslinking near the nucleus is formed at the interface between the emulsified or suspended active substance oil droplets, which form the nucleus of the microcapsules according to the application, and the external external phase, at the interface. The polymerization and / or crosslinking is based on the polyaddition reaction of the polyisocyanate with the protective colloid, preferably a polyol, forming a capsule shell or capsule wall made of polyurethane, the equation of which is as follows:

[0238] n O=C=N-R 1 -N=C=O + n HO-R 2 -OH -> (-R 2 -O-CO-NH-R 1-NH-CO-O- n

[0239] This is manifested in the generation (evolution) of gases and the release of carbon dioxide.

[0240] By already forming a polymer layer in the emulsification step, the active substance to be encapsulated, in particular an active substance having aldehyde, carboxylic acid or ester functions, is protected, if necessary, in particular in subsequent process steps, from deprotonation, oxidation or saponification, thus reducing or eliminating the loss of lipophilic active substances. These degradation products would normally lead to destabilization of the emulsion.

[0241] According to the application, the ratio of the amount of protective colloid(s) used to the amount of water phase is preferably in the range of 1 :50 to 1 :10, further preferably in the range of 1 :40 to 1 :30.

[0242] The ratio of protective colloid in the external water phase to polyisocyanate in the internal non-aqueous phase is in the range of 1 :5 to 1 :2, preferably in the range of 1 :2 to 1 :1.

[0243] Thus, the amount of protective colloid or the amount of protective colloid combination used is in the range of 1 to 8% by weight, preferably in the range of 2 to 4% by weight, even more preferably in the range of 3 to 4% by weight, relative to the total weight of the external water phase.

[0244] The at least one protective colloid can, but does not necessarily have to be, part of the capsule shell. In particular, the protective colloid having a higher reactivity as described above will react more quickly or more easily with the isocyanate groups of the polyisocyanate component, thus forming polyurethane crosslinking units which constitute part of the capsule shell or capsule wall, the amount of which is in the range of 0.1 to a maximum of 15% by weight, but preferably in the range of 1 to 5% by weight, even more preferably in the range of 1.5 to 3% by weight, relative to the weight of the capsule.

[0245] In order to facilitate the formation of the emulsion consisting of the internal non-aqueous phase and the external water phase, to stabilize the emulsion formed and to prevent the segregation of the internal non-aqueous phase (oily / organic / hydrophobic) from the external water phase (hydrophilic), in the process according to the application an emulsifier or co-emulsifier is optionally added to the external water phase. The addition of an emulsifier is optional if the protective colloid does not have or only has a low, i.e. insufficient, emulsifying power. In the process according to the application, the use of an emulsifier can advantageously be avoided if an emulsifying protective colloid is used.

[0246] In the process according to the application, an O / W emulsifier is preferably used as emulsifier, which emulsifier enables a uniform distribution of the oil droplets of the internal non-aqueous phase in the external water phase and stabilizes the emulsion. The same applies to the mixing of solids, insoluble active substances in the external water phase to stabilize the dispersion thus obtained.

[0247] For example, nonionic surfactants from at least one of the following groups can be used as emulsifiers:

[0248] - addition products of 2 to 30 mol of ethylene oxide and / or 0 to 5 mol of propylene oxide to linear fatty alcohols of 8 to 22 carbon atoms, to fatty acids of 12 to 22 carbon atoms, to alkyl phenols with 8 to 15 carbon atoms in the alkyl radical and to alkyl amines with 8 to 22 carbon atoms in the alkyl residue;

[0249] - alkyl and / or alkenyl oligoglycosides with 8 to 22 carbon atoms in the alk(en)yl residue and ethoxylated analogs thereof;

[0250] - addition products of 1 to 15 mol of ethylene oxide to castor oil and / or hydrogenated castor oil;

[0251] - addition products of 15 to 60 mol of ethylene oxide to castor oil and / or hydrogenated castor oil;

[0252] - partial esters of glycerol and / or sorbitol oligosaccharides with unsaturated, linear or saturated branched fatty acids of 12 to 22 carbon atoms and / or hydroxy carboxylic acids of 3 to 18 carbon atoms and their addition products with 1 to 30 mol of ethylene oxide;

[0253] - partial esters of polyglycerol (average self-condensation degree 2 to 8), polyethylene glycol (molecular weight 400 to 5000), trimethylolpropane, pentaerythritol, sugar alcohols (e.g. sorbitol), alkyl glucosides (e.g. methyl glucoside, butyl glucoside, dodecyl glucoside) and polyglucosides (e.g. cellulose) with saturated and / or unsaturated, linear or branched fatty acids of 12 to 22 carbon atoms and / or hydroxy carboxylic acids of 3 to 18 carbon atoms and their addition products with 1 to 30 mol of ethylene oxide, preferably

[0254] - mixed esters of pentaerythritol, fatty acids, citric acid and fatty alcohols and / or mixed esters of fatty acids with 6 to 22 carbon atoms, methyl glucoside and polyols, the polyols being preferably glycerol or polyglycerol;

[0255] - mono-, di- and trialkyl phosphates and mono-, di- and / or tri-polyglycol alkyl phosphates and salts thereof;

[0256] - lanolin alcohols;

[0257] - polysiloxane-polyalkyl-polyether copolymers and derivatives thereof; block copolymers,

[0258] such as polyethylene glycol 30 dipolyhydroxystearate;

[0259] Polymeric emulsifiers, such as Pemulen types (TR-1, TR-2) from Goodrich or TEGO®- Carbomer types from Cognis SP;

[0260] Polyalkylene glycols and glycerol carbonates.

[0261] Typical anionic emulsifiers which can be used in the process according to the application for the preparation of isocyanate-based microcapsules are fatty fatty acids having 12 to 22 carbon atoms, such as palmitic acid, stearic acid or behenic acid, and dicarboxylic acids having 12 to 22 carbon atoms, such as azelaic acid or sebacic acid.

[0262] Furthermore, in the process according to the application for the preparation of isocyanate-based microcapsules, zwitterionic surfactants can be used as emulsifiers. Zwitterionic surfactants are surface-active compounds which carry at least one quaternary ammonium group and at least one carboxylate and one sulfonate in the molecule. Particularly suitable zwitterionic surfactants are the so-called betaines, such as N-alkyl-N,N-dimethylammonium glycines (for example cocoalkyl dimethylammonium glycinate), N-acylaminopropyl-N,N-dimethylammonium glycines (for example cocoacylaminopropyl dimethylammonium glycinate) and 2-alkyl-3-carboxymethyl-3-hydroxyethyl imidazolines, each having 8 to 18 carbon atoms in the alkyl or acyl radical, and cocoacylaminoethyl hydroxyethyl carboxymethyl glycinate. Particularly preferred is the fatty acid amide derivative known by the CTFA designation cocoamidopropyl betaine.

[0263] Amphoteric surfactants are likewise suitable emulsifiers. Amphoteric surfactants are understood to mean compounds which, in addition to a C8 / 18 alkyl or acyl radical in the molecule, contain at least one free amino group and at least one carboxyl (-COOH) or sulfonic acid group (-SO3H) and can form internal salts. Examples of suitable amphoteric surfactants are N-alkylglycines, N-alkylpropionic acids, N-alkylaminobutyric acids, N-alkylaminodipropionic acids, N-hydroxyethyl-N-alkylamidopropylglycines, N-alkyltaurines, N-alkylsarcosines, 2-alkylaminopropionic acids and alkylaminoacetic acids, each having about 8 to 18 carbon atoms in the alkyl radical. Particularly preferred amphoteric surfactants are N-cocoalkylaminopropionic acid esters, cocoacylaminoethylaminopropionic acid esters and C12 / 18-acylsarcosines.

[0264] Finally, cationic surfactants can also be used as emulsifiers, among which in particular esterquats of the type, preferably methylquats of the type of quaternized di-fatty acid triethanolamine ester salts, quaternized hydroxyethylcellulose, chitosan modified with propylene glycol and quaternized with epichlorohydrin, distearyldimethylammonium chloride (DSDMAC), benzalkonium chloride, benzethonium chloride, cetyl ammonium chloride, cetyl pyridinium chloride, cetyltrimethylammonium bromide (cetrimonium bromide), dequalinium chloride.

[0265] The emulsifiers can be added to the external aqueous phase in an amount of from about 0.5 to about 10 % by weight, and preferably from about 1 to about 5 % by weight, each relative to the total weight of the external aqueous phase.

[0266] The protective colloid emulsifier aqueous solution is preferably prepared by adding the protective colloid and optionally the emulsifier to the external aqueous phase one after the other (or vice versa), or by adding the protective colloid and optionally the emulsifier to the external aqueous phase simultaneously under stirring.

[0267] It can be advantageous if, for the preparation of the polyurea / polyurethane microcapsules according to the application, the external aqueous phase can contain dissolved or dispersed stabilizers in order to prevent the segregation of the internal non-aqueous (oil) phase and the external aqueous phase.

[0268] Preferred stabilizers for the preparation of the isocyanate-based microcapsules according to the application are mainly acrylic acid copolymers with sulfonate groups. Also suitable are copolymers of acrylamide and acrylic acid, also suitable are copolymers of alkyl acrylate and N-vinylpyrrolidone, such as K15, K30 or K90 (BASF), sodium polycarboxylate, sodium polystyrene sulfonate, vinyl and methyl vinyl ether-maleic anhydride copolymers and ethylene, isobutylene or styrene-maleic anhydride copolymers, microcrystalline cellulose (for example sold under the name Avicel®), detergent gum, xanthan gum or carboxymethylcellulose.

[0269] The amount of stabilizer can be in the range of from 0.01 to 10 % by weight, in particular in the range of from 0.1 to 3 % by weight, each relative to the external aqueous phase.

[0270] The oil-in-water emulsion is prepared by mixing the internal non-aqueous phase and the external aqueous phase. The weight ratio of the internal non-aqueous phase to the external aqueous phase is preferably in the range of from 2:1 to 1 :10, even more preferably in the range of from 1 :2 to 1 :4.

[0271] ​The emulsion formation of a liquid active substance or the dispersion formation of a solid active substance, i.e. the emulsification or dispersion of the internal non-aqueous phase or oil phase in the external aqueous phase or hydrophilic phase, takes place under high turbulence or strong shear. By the intensity of the turbulence or shear, the diameter of the microcapsules obtained can be specifically adjusted. The droplet size can be measured by light scattering or microscopy. In this case, the preparation of the microcapsules can be carried out continuously or discontinuously. With increasing viscosity of the aqueous phase or decreasing viscosity of the oil phase, the size of the resulting capsules generally decreases.

[0272] The process for the preparation of polyurea / polyurethane microcapsules according to the application can be carried out, for example, by means of a forced metering pump using an "in-line" technique, or also in a customary dispersing device or emulsifying device with stirring.

[0273] The internal non-aqueous phase is emulsified or dispersed into the external aqueous phase by means of an emulsifying turbine (IKA Eurostar 20 high-speed stirrer) to produce the microcapsules according to the application. The process of emulsification in step (a3) of the process according to the application is advantageously carried out at a stirring speed of from 1000 to 5000 revolutions per minute, preferably from 3000 to 4000 revolutions per minute, for a period of from 30 seconds to 20 minutes, preferably from 1 to 4 minutes.

[0274] After the emulsification or dispersion step (a3) has been completed, an oil-in-water emulsion or dispersion is present, in which the internal oil phase with the active substance to be encapsulated is finely dispersed or emulsified in the form of droplets in the external aqueous phase.

[0275] In the subsequent step (a4) of the process according to the application, the first polymerization and / or crosslinking of the material of the capsule shell or capsule wall likewise takes place with stirring. The first crosslinking is carried out by the addition of at least one first amino acid or at least one amino acid hydrochloride, preferably in the form of an aqueous solution, in the presence of a catalyst. The addition of the amino acid or amino acid hydrochloride and the catalyst is preferably carried out at a temperature of from 20 to 30°C.

[0276] The at least one first amino acid is selected from the group consisting of arginine, histidine, lysine, tryptophan, ornithine and mixtures thereof.

[0277] It is generally advantageous to use the amino acid as a hydrochloride. The hydrochlorides of the above-mentioned amino acids are more readily soluble in water and thus more readily soluble in the external aqueous phase. Furthermore, by using the amino acid as a hydrochloride, the pH value of the reaction mixture is shifted into the acidic range, which, in addition to improving the solubility, leads to an increase in the reactivity between the at least one polyisocyanate and the first amino acid and thus to an increase in the polymerization and / or crosslinking between these two components.

[0278] The at least one amino acid hydrochloride is selected from the group consisting of arginine hydrochloride, histidine hydrochloride, lysine hydrochloride, tryptophan hydrochloride, ornithine hydrochloride and mixtures thereof.

[0279] The amino acids arginine, lysine and ornithine or the corresponding amino acid hydrochlorides are compounds which each have two amino groups on the side chain. The amino acids histidine and tryptophan or the corresponding hydrochlorides have one amino group and one NH function on the side chain. The above-mentioned amino acids or their amino acid hydrochlorides thus have multifunctionality for polymerization with at least one polyisocyanate.

[0280] As a result of the crosslinking between the functional groups of the at least one polyisocyanate and the at least one amino acid or amino acid hydrochloride, a first crosslinking unit or a first crosslinking matrix is formed, which first crosslinking unit or matrix respectively becomes a constituent part of the capsule shell or capsule wall.

[0281] Of the above-mentioned amino acids, the basic-reacting amino acid arginine or its hydrochloric acid analogue is particularly preferred as crosslinker because of its water solubility, high reactivity and pH value, both as an amino acid and as a hydrochloride.

[0282] From an environmental point of view, the use of amino acids or amino acid hydrochlorides as crosslinkers is particularly advantageous in terms of biodegradability and biocompatibility.

[0283] The amino acid or amino acid hydrochloride, i.e. the first crosslinker, is added to the emulsion either in the form of, for example, a solid or preferably in the form of an aqueous solution. The amino acid or amino acid hydrochloride is present in the aqueous solution in a concentration of 0.5 to 2 mol / l, preferably in a concentration of 1 mol / l.

[0284] The amount of at least one amino acid or at least one amino acid hydrochloride is adjusted in such a way that, for each mole of isocyanate groups, 1 to 3 moles of amino groups are added, preferably 1 to 3 moles of amino groups.

[0285] The first crosslinking in the process according to the application takes place within a period of from about 10 minutes to 20 minutes, preferably within a period of from 12 to 18 minutes, and most preferably within a period of about 15 minutes.

[0286] The amount of at least one amino acid or at least one amino acid hydrochloride is usually adjusted in such a way that, for each mole of isocyanate groups, 1 to 3 moles of amino groups are added, preferably 1 to 2 moles of amino groups.

[0287] No specific action is required to induce polymerization between the at least one polyisocyanate or several polyisocyanates and the first amino acid or amino acid hydrochloride. The reaction, which forms the first crosslinking unit or the first crosslinking matrix, begins immediately after the amino acid or the hydrochloric acid amino acid is added to the oil-in-water emulsion or dispersion. No catalyst is required since the reaction between the at least one polyisocyanate or several polyisocyanates and the amino acid or the amino acid hydrochloride is sufficiently fast.

[0288] In the process according to the application, the formation of the first crosslinking unit is based on the polyaddition of the polyisocyanate(s) with the amino acid or the amino acid hydrochloride. The first crosslinking unit forming the capsule shell or capsule wall is based on a polyurea structure. The polyurea bond or polyurea structure is formed by the polyaddition of the amino group (-NH2) of the at least one amino acid or at least one amino acid hydrochloride with the isocyanate group of the at least one polyisocyanate:

[0289] n O = C = N - R 1 - N = C = O + n H2N - R 2 - → (- O - NH - R 1 - NH - CO - NH - R 2 - ) n

[0290] For the process according to the application, the first crosslinking matrix or the first crosslinking unit, in particular the polyurea crosslinking unit, for building the capsule shell or capsule wall is formed by interfacial polymerization at the interface of the emulsified or suspended oil droplets containing the lipophilic active substance to be encapsulated.

[0291] By structuring the first crosslinking matrix or the first crosslinking unit, the emulsified or dispersed oil droplets with the core material, i.e. the encapsulated active substance, at the interface are surrounded by the external crosslinking matrix or crosslinking unit, thus creating a capsule wall, making it difficult for the encapsulated active substance to diffuse.

[0292] The addition of a catalyst in the emulsion or dispersion accelerates the reaction between the polyisocyanate and the amino acid or the amino acid hydrochloride and catalyzes the reaction favoring the formation of the polyurea crosslinking matrix.

[0293] The catalyst added in the process according to the application is preferably diazabicyclo[2.2.2]octane (DABCO), also known as triethylenediamine (TEDA), a bicyclic tertiary amine. DABCO is generally used as a catalyst for the preparation of polyurethane plastics. The tertiary amine with a free electron pair favors the reaction between the at least one polymerizable polyisocyanate in the internal non-aqueous phase and the amino group of the amino acid or the amino acid hydrochloride in the external aqueous phase.

[0294] In addition to DABCO, catalysts based on bismuth or tin are also used to catalyze the initial crosslinking, for example catalysts based on bismuth (II) salts or based on bismuth (III) salts, as explained in K.C. Frisch & L.P. Rumao, Catalysis in Isocyanate Reactions, Polymer Reviews, 1970, 5:1, pages 103-149, DOI: 10.1080 / 15583727008085365, the disclosure of which in this respect is incorporated in its entirety into the present specification.

[0295] Particularly preferably, diazabicyclo[2.2.2]octane (DABCO) is used as catalyst.

[0296] According to the application, it is preferred that DABCO is combined with one of the above-mentioned catalysts. Such a mixture leads to a multiplication of the reactivity, as explained in K.C. Frisch & L.P. Rumao, Catalysis in Isocyanate Reactions, Polymer Reviews, 1970, 5:1, pages 103 to 149, DOI: 10.1080 / 15583727008085365, the disclosure of which in this respect is incorporated in its entirety into the present specification.

[0297] In the process according to the application, DABCO and the above-mentioned catalysts preferably catalyze the polyurethane reaction between at least one polymerizable polyisocyanate having two or more isocyanate groups and a diol or polyol.

[0298] The amount of catalyst added to the emulsion or dispersion is in the range of 0.01 to 1 % by weight, and preferably in the range of 0.05 to 0.2 % by weight, based on the total weight of the emulsion or dispersion. In the case of a sluggish polymerization reaction, the required amount of catalyst can be adjusted accordingly.

[0299] The ratio of catalyst in the emulsion or dispersion to at least one polyisocyanate or isothiocyanate in the internal non-aqueous phase is preferably in the range of 1 :20 to 1 :50.

[0300] It has proven advantageous to first disperse or dissolve the catalyst in water and then add it to the emulsion or dispersion under stirring.

[0301] The addition of the amino acid or amino acid hydrochloride and the catalyst is preferably carried out at a stirring speed of 500 to 2000 revolutions per minute, particularly preferably at a stirring speed of 1000 to 1500 revolutions per minute, and preferably at a temperature of 20 to 30°C, preferably at a temperature of 22 to 26°C.

[0302] The first polymerization and / or crosslinking in the process according to the application is carried out in a time of about 10 to 20 minutes, preferably in a time of 12 to 18 minutes, and most preferably in a time of about 15 minutes.

[0303] Surprisingly, the addition of the catalyst after the emulsification or suspension step leads to a significant increase in the stability of the capsules. The capsules produced in this way have significantly higher stability even after 10 days at 50°C compared to microcapsules produced without the addition of catalyst, and the free fragrance oil is significantly reduced.

[0304] With the catalyst diazabicyclo[2.2.2]octane (DABCO) particularly stable microcapsules can be prepared.

[0305] In the process according to the application, the first polymerization and / or crosslinking step (a) is followed by a further, i.e. second, polymerization and / or crosslinking step (b), which step serves to further crosslink the capsule shell or capsule wall by adding at least one hydroxyl donor to the oil-in-water emulsion or dispersion obtained in process step (a4).

[0306] The at least one hydroxyl donor is preferably a polyol having two or more hydroxyl functions, which has good to very good water solubility at temperatures above 40°C.

[0307] The hydroxyl donor is selected from the group consisting of glycerol, propylene glycol, 1,3,5-trihydroxybenzene, starch, modified (modified) starch, cellulose derivatives such as hydroxyethyl cellulose, in particular quaternized hydroxyethyl cellulose or carboxymethyl cellulose, gum arabic (Senegal and Seyal types) and mixtures thereof. Glycerol and starch are preferred, glycerol is most preferred.

[0308] The starch used in the process according to the application is selected from the group consisting of corn starch, potato starch, rye starch, wheat starch, barley starch, oat starch, rice starch, pea starch, tapioca starch and mixtures thereof.

[0309] The modified starch is preferably a chemically modified starch, i.e. an acid-modified starch, an alkali-modified starch, an oxidized starch, an acetylated starch, a succinylated starch or an octenyl succinylated starch.

[0310] According to the application, a combination of the two different hydroxyl donors mentioned above can also be used to prepare the microcapsules according to the application.

[0311] Depending on their size, the hydroxyl donors mentioned above have different reaction rates with the isocyanate groups of the at least one polyisocyanate. For example, glycerol reacts faster with isocyanate groups than, for example, starch.

[0312] The combination of glycerol with starch or modified starch or glycerol with quaternized hydroxyethyl cellulose or gum arabic of the Seyal type has therefore proved to be particularly advantageous. By such a combination, the properties of both hydroxyl donors mentioned above can be achieved: on the one hand the high reaction rate of glycerol and on the other hand the number of polymerizable functional groups of starch.

[0313] By the reaction of the at least one polyisocyanate and / or isothiocyanate with the hydroxyl groups of the hydroxyl donor, a further, i.e. second, crosslinking matrix or second crosslinking unit for building or constructing the capsule shell or capsule wall is formed, which has a structure similar to the first crosslinking unit mentioned above consisting of polyisocyanate and protective colloid.

[0314] The polyaddition of at least one polyisocyanate with a hydroxyl donor leads to the formation of so-called urethane bridges (-NH-CO-C-) by adding the hydroxyl group of the hydroxyl donor (-OH) to the carbon atom of the carbon-nitrogen bond of the polyisocyanate group (-N=C=O).

[0315] By forming such further polyurethane crosslinking units, the first polyurea crosslinking units formed in the first polymerization and / or crosslinking step (a4) are further crosslinked and densified.

[0316] In order to obtain a particularly effective, dense and stable crosslinking, the second polymerization and / or crosslinking step (b) with the hydroxyl donor is carried out at a temperature of 40°C to 60°C, preferably at a temperature of 45°C to 55°C, more preferably at a temperature of 45°C to 50°C.

[0317] It is furthermore preferred that the step of further crosslinking is carried out by adding the hydroxyl donor at a stirring speed of 900 revolutions per minute to 1700 revolutions per minute, preferably 1000 revolutions per minute to 1300 revolutions per minute.

[0318] It is highlighted in this context that the addition of a water-like hydroxyl donor leads to a particularly stable crosslinking, thus to a particularly stable capsule shell or capsule wall. The concentration of the hydroxyl donor in the aqueous solution is preferably 10% to 70%, even more preferably the concentration of the hydroxyl donor in the aqueous solution is 40% to 60%.

[0319] The second crosslinking step (b) in the method according to the present application is followed by a further, i.e. third, polymerization and / or crosslinking step (c). In this third crosslinking step, at least one additional, i.e. second, amino acid is added to the oil-in-water emulsion obtained in the crosslinking step (b).

[0320] The at least one second amino acid is selected from the group consisting of arginine, histidine, aspartic acid, lysine, glycine, alanine, proline, cysteine, glutamine, leucine, serine, tryptophan, valine, threonine, ornithine, uric acid and mixtures thereof.

[0321] The above-mentioned amino acids are compounds having at least one amino group on the side chain, thus having a functionality for polymerization and / or crosslinking with at least one polyisocyanate.

[0322] Among the above-mentioned amino acids, the basic reacting amino acids such as histidine, lysine or arginine or their hydrochloric acid analogs are particularly preferred as amino acids and hydrochloride salts due to their high reactivity and pH value.

[0323] Due to its water solubility, arginine is particularly preferred as a crosslinking agent in the method according to the present application.

[0324] From an environmental point of view, the use of amino acids or amino acid hydrochlorides as crosslinking agents is particularly advantageous in terms of biodegradability and biocompatibility.

[0325] The second amino acid is either added as emulsion or dispersion, for example as a solid, or preferably in the form of an aqueous solution to the emulsion or dispersion. The second amino acid is present in the aqueous solution in a concentration of 0.5 to 2 mol / l, preferably in a concentration of 1 mol / l.

[0326] The amount of at least one second amino acid or amino acid hydrochloride is generally adjusted such that for each mole of isocyanate groups, 1 to 3 moles of amino groups, preferably 1 to 2 moles of amino groups, are added.

[0327] The addition of the second amino acid or amino acid hydrochloride is preferably carried out at a stirring speed of 500 revolutions per minute to 2000 revolutions per minute, in particular preferably at a stirring speed of 1000 revolutions per minute to 1500 revolutions per minute, and at a temperature of 60 °C to 80 °C, preferably at a temperature of 60 °C.

[0328] By adding the second amino acid, a third crosslinking matrix or third crosslinking units for building the capsule shell or capsule wall are constructed in the process according to the application. These third crosslinking units are based on the polyaddition of the individual polymer or oligomer of the polyisocyanate(s) with the amino acid, forming a capsule shell or capsule wall based on polyurea structures. By the polyaddition of the amino group (-NH2) of the at least one amino acid on the isocyanate group of the at least one polyisocyanate, a polyurea bond or polyurea structure is formed:

[0329] n O=C=N-R 1 -N=C=O + n H2N-R 2 - +→ (-O-NH-R 1 -NH-CO-NH-R 2 -) n

[0330] By constructing such further polyurea crosslinking units, the polyurea crosslinking units and the polyurethane crosslinking units formed in the first and second polymerization and / or crosslinking steps (a4) and (b) are further crosslinked and densified.

[0331] The third crosslinking in the process according to the application is carried out in a time of about 10 minutes to 20 minutes, preferably in a time of 12 to 18 minutes, and most preferably in a time of about 15 minutes.

[0332] The third crosslinking step is carried out at a temperature of 60 to 80 °C, preferably at a temperature of 60 °C.

[0333] By the combination of a first polymerization or crosslinking step between the polyisocyanate and the first amino acid, a second polymerization or crosslinking step between the polyisocyanate and the hydroxyl donor and a third polymerization or crosslinking step between the polyisocyanate and the second amino acid, polyurea and polyurethane crosslinking units or crosslinking matrices can be generated, which build the capsule shell and the capsule wall, respectively. Furthermore, by the sequence of crosslinking steps in the process according to the present application, the first, second and third polyurea and polyurethane crosslinking units are further crosslinked spatially and between each other.

[0334] The more the number of crosslinking functions, the greater the spatial crosslinking and the more stable the capsule shell or capsule wall of the resulting microcapsules. In addition to the number of functions, the chain length of the individual building blocks also has a great influence on the mechanical properties, i.e. the stability, of the capsules. For example, the large number of hydroxyl groups in starch allows particularly pronounced spatial crosslinking. Longer chain capsule shell or capsule wall building blocks, such as polyisocyanates, lead to the formation of more stable capsule shells or capsule walls.

[0335] During the above-mentioned crosslinking steps, the stirring power is reduced, preferably to a stirring speed of about 800 to 1200 revolutions per minute, in order not to destroy the crosslinking units being formed, which constitute the capsule shell.

[0336] After the third polymerization or crosslinking step and the complete crosslinking and construction of the capsule shell or capsule wall, the capsules produced according to the process of the present application exist as crude microcapsules in the form of an aqueous dispersion or slurry / syrup.

[0337] After crosslinking, the microcapsules in the slurry still have a flexible shell, which is not particularly stable and therefore easily ruptures. For this purpose, the shell of the microcapsules is hardened (cured). Preferably, the curing is achieved by gradually raising the microcapsule dispersion to a temperature of at least 60°C, preferably to a temperature in the range of 60 to 65°C, up to the boiling point of the microcapsule dispersion. The hardening is usually carried out over a period of at least 60 minutes, preferably 2 to 4 hours.

[0338] It is furthermore advantageous to add a substance for the curing in the external aqueous phase. For this purpose, a natural plant tannin of the tannin type is used, which is chemically a proanthocyanidin, which is found in particular in tropical and subtropical dicotyledonous plants, shrubs and tree leaves. The molecular weight of the terpenoids is usually in the range of 500 to 3000 KDa. A preferred example of a suitable tannin is Corigallin. For the hardening, an aqueous preparation of the tannin is added to the aqueous dispersion containing the crude microcapsules. The tannin is usually added in a range of about 0.1 to about 2% by weight, preferably in a range of about 0.5 to about 1.5% by weight, relative to the microcapsules.

[0339] After the curing step (d) according to the method of the present application, in a further method step (e) at least one release agent is added to the microcapsule dispersion or microcapsule slurry, which is attached to the microcapsule shell or microcapsule wall surface, respectively, or preferably incorporated into the microcapsule shell or microcapsule wall.

[0340] The release agent is typically a liquid or pasty substance, which prevents adhesion between two materials. In the case of the present application, the substance is incorporated into the microcapsule shell or microcapsule wall, respectively, and forms ionic or even covalent bonds with the existing cross-linking structure of the capsule material by functional groups, such as OH groups or COOH groups.

[0341] The at least one separating agent used in the method according to the present application is selected from the group consisting of fatty acids, fatty alcohols, fatty acid esters and animal and vegetable waxes.

[0342] Fatty acids are aliphatic monocarboxylic acids, usually with unbranched carbon chains. Fatty acids differ in the number of carbon atoms (chain length), and unsaturated fatty acids also differ in the number and position of double bonds. Fatty acids can be divided into short-chain fatty acids (up to 6 to 8 carbon atoms), medium-chain fatty acids (8 to 12 carbon atoms) and long-chain fatty acids (13 to 21 carbon atoms) depending on their chain length.

[0343] Fatty alcohols are aliphatic, long-chain, monovalent, mainly primary alcohols. The hydrocarbon residue of natural fatty alcohols is usually unbranched, and synthetic fatty alcohols are usually branched. The carbon chain has 6 to 30 carbon atoms and can be mono- or polyunsaturated. Fatty alcohols occur in natural waxes, bound as carboxylic acid esters, for example in wool wax or whale wax, and are usually referred to as wax alcohols.

[0344] Waxes are organic compounds that melt above 40°C and then form a liquid of low viscosity. The chemical composition and origin of waxes can vary greatly. The main component of these mixtures of substances are esters of fatty acids with long-chain aliphatic primary alcohols, so-called fatty alcohols. These esters differ in structure from fats and fatty oils, which are triglycerides containing fatty acids. In addition, these waxes also contain free long-chain aliphatic carboxylic acids, ketones, alcohols and hydrocarbons. Waxes can be of animal or plant origin.

[0345] The at least one release agent in the method according to the present application is preferably selected from the following group, which comprises:

[0346] long-chain, aliphatic, straight-chain or branched, saturated or unsaturated carboxylic acids (fatty acids) with 12 to 30 carbon atoms,

[0347] in particular lauric acid (12:0), tridecanoic acid (13:0), myristic acid (14:0), pentadecanoic acid (15:0), palmitic acid (16:0),

[0348] Heptadecanoic acid (17:0), stearic acid (18:0), nonadecanoic acid (19:0), arachidic acid (20:0), teicoic acid (21:0), behenic acid (22:0), ceramide (24:0), ceramide (26:0), limonitic acid (28:0), and beeswax acid (30:0); myristone acid (14:1), palmitoleic acid (16:1), heptadecanoic acid (17:1), octadecenoic acid (18:1), oleic acid (18:1), tranexamic acid (18:1), isoleic acid (1... 8:1), codoleic acid (20:1), stigmocarboxylic acid (20:1), cetylenoic acid (22:1), erucic acid (822:1), nervonic acid (24:1), linoleic acid (18:2), α-linolenic acid (18:3), γ-linolenic acid (18:3), calendulatic acid (18:3), punicic acid (18:3), α-tungolenic acid (18:3), β-tungolenic acid (18:3), octadecanoic acid (18:4), arachidonic acid (20:4), eicosapentaenoic acid ( 20:5), docosahexaenoic acid (ADA) (22:4), docosapentaenoic acid (DPA-3) (22:5), docosahexaenoic acid (22:6) and docosahexa ...DPA-3) 24:6); Phytic acid;

[0349] - Long-chain, aliphatic, straight-chain or branched, saturated or unsaturated primary alcohols (fatty alcohols) with 12 to 30 carbon atoms, especially lauryl alcohol (12:0), myristyl alcohol (14:0), palmitol (16:0), heptadecanol (17:0), stearyl alcohol (18:0), arachidyl alcohol (20:0), behenyl alcohol (22:0), lignoceryl alcohol (24:0), wax alcohol (26:0), linalool (28:0) and beeswax alcohol (30:0); palmitoleyl alcohol (16:1), oleyl alcohol (18:1), transoleyl alcohol (18:1), linoleyl alcohol (18:2), γ-linolenic acid (18:3);

[0350] -Esters of long-chain aliphatic saturated carboxylic acids having 12 to 30 carbon atoms and long-chain aliphatic primary alcohols having 12 to 30 carbon atoms, particularly lauryl palmitate, myristyl palmitate, cetyl arachidate and stearyl behenate.

[0351] - Animal and plant waxes, especially wool wax, Chinese wax, beeswax, sunflower seed wax, rice bran wax, carnauba wax, Pinova wax, rapeseed wax, soybean wax, candelillawachs, jojoba oil Cork wax, guarumawachs, cotton wax, linseed wax, peat wax, rose wax, jasmine wax, pumpkin pita wax (Peetha-Wachs vom) ), Myrica cerifera, fig wax, berry wax,

[0352] and mixtures of two or more of the above-mentioned release agents.

[0353] Among the above-mentioned carboxylic acids, saturated fatty acids are preferred. Most preferred in the process according to the application is the use of the above-mentioned specified animal and vegetable waxes, since they have a lower melting point and are easier to incorporate into the microcapsule shell or microcapsule wall.

[0354] The at least one release agent has a dual function: it is incorporated into the microcapsule shell or microcapsule wall and forms ionic or covalent bonds with the crosslinking units or the crosslinking matrix, which on the one hand leads to a further stabilization of the microcapsule shell. On the other hand, by placing the release agent in the microcapsule shell or microcapsule wall, a predetermined breaking point for the degradability of the microcapsule shell, i.e. a location in the microcapsule wall, is created, which is designed to be the first place where degradation of the microcapsule material occurs. The degradability of the microcapsule shell or microcapsule wall is thus promoted. In addition, the use of a release agent that stabilizes the microcapsule shell or microcapsule wall also allows a reduction of other capsule wall materials, which have a lower or no biodegradability at all.

[0355] The release agent is added to the microcapsule dispersion or microcapsule slurry in an amount of 1 to 10% by weight relative to the capsule shell. Preferably, the release agent is added in an amount of 2 to 5% by weight relative to the capsule shell.

[0356] The at least one separating agent is added to the microcapsule dispersion or microcapsule slurry at a temperature of at least 60°C up to the highest boiling point of the microcapsule dispersion, preferably at a temperature of 80°C. At this temperature, the release agent is present in liquid or molten form, so it can be easily melted and incorporated into the existing crosslinked structure of the microcapsule shell.

[0357] After the addition of the at least one release agent, a post-curing step is carried out on the polyurea / polyurethane microcapsules obtained in step (f), preferably at a temperature of at least 60°C to 100°C for 60 to 240 minutes.

[0358] The microcapsules produced according to the process of the application are present in the form of a dispersion in water after curing, which is also referred to as microcapsule dispersion or microcapsule slurry. The microcapsules in this form are essentially ready for sale.

[0359] In order to prevent the separation or creaming of this suspension and thus to achieve a high storage stability, a viscosity of the suspension of 12 to 1500 mPas has proven to be advantageous. In order to achieve the desired viscosity of the suspension, preferably a thickening agent is used.

[0360] The thickening agent is preferably xanthan gum, diutan, carboxymethylcellulose (CMC), microcrystalline cellulose (MCC) or guar gum.

[0361] To improve the durability, one or more preservatives are optionally added to the microcapsule slurry or the microcapsule slurry is subjected to a drying process.

[0362] It is preferred to use 1,2-hexanediol, 1,2-octanediol or Parmetol as preservative.

[0363] As an alternative, the microcapsules are separated and dried for storage purposes.

[0364] In principle, methods like lyophilisation are feasible, but spray drying, for example in a fluidised bed, is preferred. It has proven advantageous to further add polysaccharides, preferably dextrins and in particular maltodextrins, to the dispersion at a temperature of about 20°C to about 50°C and preferably about 40°C, which support the drying process and protect the capsules during the drying process. In this case, the polysaccharides can be used in an amount of about 50 to about 150 wt.-% and preferably about 80 to about 120 wt.-% in the dispersion relative to the capsule mass.

[0365] The spray drying itself can be carried out continuously or batchwise in a conventional spray apparatus, with an inlet temperature of about 170 to about 200°C and preferably about 180 to 185°C and an outlet temperature of about 70 to about 80°C, preferably about 72 to 78°C.

[0366] An important criterion for the suitability of the microcapsules is the weight ratio of core material to capsule wall material. On the one hand, in order to make the capsules as useful as possible, as high a core material content as possible is striven for. On the other hand, the capsules must have a sufficient amount of capsule wall material to ensure the stability of the capsules.

[0367] It has proven particularly advantageous according to the application that the microcapsules are designed to have a weight ratio of core material to capsule wall material of 50:50 to 90:10, preferably 70:30 to 80:20.

[0368] The microcapsules produced according to the method of the application can be characterised by the d(0.5) value of their size (particle size) distribution, i.e. 50% of the produced capsules are larger than this value and 50% of the capsules are smaller than this value.

[0369] The microcapsules according to the application are produced from hexamethylene diisocyanate and 4,4'-diphenylmethane diisocyanate in a ratio of 75:25. In addition, lysine*HCI is used as the first amino acid, glycerol as the hydroxyl donor and arginine as the second amino acid. DABCO is used as catalyst and modified starch as protective colloid. Beeswax is added as a release agent.

[0370] For determining the particle size, the microcapsules according to the application were dispersed in water in the range of the dynamic process and the particle size was then determined by means of laser diffraction. Depending on the size of the capsules, the laser beam is refracted in different ways, so that it can be converted into a size. For this purpose, the Mie theory was used. The particle measurement was carried out using a MALVERN Mastersizer 3000.

[0371] The microcapsules according to the application are characterized in that they have a particle size distribution with a d(0.5) value of 10 pm to 100 pm, preferably a d(0.5) value of 20 pm to 65 pm. The respective particle size distribution of the microcapsules according to the application and the microcapsules of the prior art is shown in Figure 2

[0372] A direct comparison of the microcapsules shows that the method according to the application makes it possible to obtain good microcapsules with the same particle size distribution as the microcapsules of the prior art based on a polyurea / polyurethane structure without release agent.

[0373] Figure 3 Infrared images of the microcapsules according to the application and the microcapsules of the prior art are shown.

[0374] The microcapsules according to the application were prepared from hexamethylene diisocyanate and 4,4'-diphenylmethane diisocyanate in a ratio of 75:25. In addition, lysine*HCI was used as the first amino acid, glycerol as the hydroxyl donor and arginine as the second amino acid. DABCO was used as catalyst and modified starch as protective colloid. Beeswax was added as release agent. The microcapsules of the prior art are based on a polyurea / polyurethane microcapsule without release agent.

[0375] From the figures, a clear difference between the bands can be identified, in particular in the fingerprint region. At 1050 cm -1 , a band can be identified which is significantly stronger than in the prior art, which is attributed to the polyurethane and the polyester. The polyester is on the one hand derived from the ester bonds of the octenyl succinated starch and on the other hand from the ester bonds of the release agent, for example the wax. The band at 1170 cm -1 can be attributed to a polyester. The double vibration in the range from 2500 to 3000 cm -1 indicates an increasing proportion of carbon chains produced by the release agent. The comparison of the infrared spectra further shows that both the microcapsules according to the application and the microcapsules of the prior art consist of a polyurea / polyurethane polymer.

[0376] In addition, the method for preparing polyurea / polyurethane microcapsules according to the application has the advantageous feature that the individual crosslinking steps are carried out independently of the pH value. Thus, the method according to the application is easier to implement than the encapsulation method according to the prior art.

[0377] ​Although the implementation is simpler and shorter, the method according to the present application makes it possible to produce microcapsules with better performance, i.e. without loss or impairment in the functionality of the microcapsules, for example olfactory properties and positive secondary properties, such as high stability, i.e. the ability to retain the active substance.

[0378] Advantageously, the cross-linking step, which is independent of the pH value, also allows the encapsulation of lipophilic active substances with aldehyde, carboxylic acid or ester functions. With the prior art microcapsules based on polyisocyanates, it is usually only possible to coat (encapsulate) selected active substances. However, polyisocyanate encapsulation according to the prior art is not suitable for the encapsulation of fragrances or perfume oils with aldehyde, carboxylic acid or ester functions. During the encapsulation process at alkaline pH values, the carboxylic acids are deprotonated, the oxidic aldehydes (carboxylic acids) are similarly deprotonated and the esters are saponified, resulting in the occurrence of a loss of the lipophilic active substance and, on the other hand, the resulting emulsion becomes unstable. The use of such microcapsules is therefore limited in terms of the active substance and is therefore only suitable for a small number of fragrances or perfume oils, while the microcapsule encapsulation method excludes the use of fragrances or perfume oils with aldehyde, carboxylic acid or ester functions. However, fragrances with aldehyde, carboxylic acid or ester functions are precisely one of the most important representatives of fragrances or perfume oils. The cross-linking step in the method according to the present application, which is independent of the pH value, therefore makes it possible to effectively encapsulate such lipophilic fragrances or perfume oils.

[0379] According to the method according to the present application, alternating defined polyurea and polyurethane-based cross-linking units or cross-linking matrices can be deposited around the core containing the lipophilic active substance by interfacial polymerization, resulting in a structure of a stable capsule wall or capsule shell. The main components of the capsule shell or capsule wall essentially form a polyurea or polyurethane cross-linking matrix or cross-linking unit, respectively. In addition, a protective colloid, such as starch, can be present in the capsule shell or capsule wall via polyurethane linkers. The capsule shell or capsule wall is further stabilized by the incorporation of a release agent.

[0380] In addition, the method according to the present application is characterized in that the protective colloid, the amino acid, the hydroxyl donor as a main component and the polyisocyanate are preferably polymerized and / or cross-linked by a specific catalytic mechanism, making it possible to produce bio-based and biodegradable microcapsules based on biocompatible polymers. Unlike the prior art microcapsules, in which polyisocyanates make up a large proportion of the capsule shell material, the situation is precisely the opposite: in the microcapsules according to the present application, the polyisocyanate is no longer the main material, but only serves as a cross-linker for the amino acid and the other components mentioned above.

[0381] Thus, the process according to the present application allows the replacement of part of the polyisocyanate with biodegradable wall materials such as protective colloids, amino acids, hydroxyl donors and release agents, thereby reducing the proportion of polyisocyanate without resulting in a loss or loss of functionality of the microcapsules, such as olfactory properties and positive secondary properties such as high stability, i.e. the retention capacity of the active substance. Thus, the process according to the present application can produce microcapsules which, on the one hand, have excellent functionality, while at the same time having good biodegradability.

[0382] Surprisingly, it has been found that the process according to the present application can produce microcapsules with a reduced amount of polyisocyanate of up to 60% without resulting in a loss or loss of stability of the microcapsules obtained, as shown in the examples below. Thereby, microcapsules can be produced which contain a reduced amount of the starting material isocyanate and the same amount of the active substance to be encapsulated.

[0383] In another aspect, the present application relates to biodegradable polyurea / polyurethane microcapsules produced according to the process of the present application.

[0384] The biodegradable polyurea / polyurethane microcapsules are characterized in that they consist of or comprise:

[0385] (i) a core comprising at least one hydrophobic active agent; and

[0386] (ii) a capsule shell comprising:

[0387] - a reaction product of the polymerization and / or crosslinking of at least one polyisocyanate having two or more isocyanate groups with at least one first amino acid or amino acid hydrochloride, of a further polymerization and / or crosslinking with at least one hydroxyl donor, and of a further polymerization and / or crosslinking with at least one second amino acid in the presence of a protective colloid; and

[0388] - at least one release agent.

[0389] The alternating polymerization and / or crosslinking of the polyisocyanate units having amino or hydroxyl functional groups results in a stable capsule wall consisting of alternating defined, dense and thus stable crosslinked matrices or crosslinked units based on polyurethane and polyurea.

[0390] In a preferred embodiment, the capsule shell of the biodegradable polyurea / polyurethane microcapsules according to the present application comprises or consists of:

[0391] (a) a first crosslinked matrix or first crosslinked unit consisting of the polymerization and / or crosslinking of at least one polyisocyanate having two or more isocyanate groups with at least one protective colloid and at least one first amino acid;

[0392] (β) a second crosslinking matrix or second crosslinking unit consisting of crosslinking of at least one polyisocyanate having two or more polyisocyanate groups and at least one hydroxyl donor;

[0393] (γ) a third crosslinking matrix or third crosslinking unit consisting of crosslinking of at least one polyisocyanate having two or more polyisocyanate groups and at least one second amino acid; and

[0394] (δ) at least one release agent.

[0395] The first crosslinking matrix or first crosslinking unit of the capsule shell of the microcapsule according to the present application is a polyurea-based network. The second crosslinking matrix or second crosslinking unit is a polyurethane-based network and the third crosslinking matrix or third crosslinking unit is a further polyurea-based network. The composition of the polyurea and polyurethane crosslinking matrix or crosslinking unit depends on the polyisocyanate used and the crosslinking agents, i.e. the protective colloid, the first amino acid, the hydroxyl donor and the second amino acid.

[0396] In addition to the polyurethane formation and the polyurea formation described above, due to the reactivity of the polyisocyanate, side products such as urea, allophanate, biuret, uretdione, carbodiimide and ketimine, etc. are generated in the crosslinking step described above, as explained by M. F. Sonnenschein, Introduction to Polyurethane Chemistry, Polyurethanes: Science, Technology, Markets, and Trends, First Edition, 2015, John Wiley & Sons, pages 105 to 126, the disclosure of which in this respect is incorporated in its entirety into the present specification. These side products are part of the capsule shell or capsule wall.

[0397] By building the capsule wall based on multiple separate, alternately defined crosslinking matrices or crosslinking units, it is possible to produce particularly stable microcapsules with excellent sensory properties, while the shell composition can be significantly reduced. Finally, the incorporation of a release agent also contributes to the stability of the capsule shell.

[0398] Surprisingly, the polyurea / polyurethane perfume capsules produced according to the process of the present application have a higher stability and reduce the unintentional leakage of fragrance oil, as shown in the following examples. This can be attributed, inter alia, to a more efficient encapsulation of the perfume.

[0399] Surprisingly, it has been found that the microcapsules produced according to the process of the present application have at least 1.5 times, preferably at least 2 times, higher stability compared to the polyurea / polyurethane microcapsules of the prior art, as shown in the following examples.

[0400] The microcapsules according to the present application have a content of free hydrophobic active substance of 0.5 wt.-% or below, preferably a content of 0.3 wt.-% or below, even more preferably a content of 0.2 wt.-%.

[0401] Furthermore, the polyurea / polyurethane microcapsules according to the present application show a significant improvement in the sensory performance (perfume release) compared to the prior art capsules, which can be attributed to the stable encapsulation of the active substance and the low active substance loss associated therewith. Thus, the microcapsules according to the present application exhibit a significantly higher sensory intensity when releasing the fragrance by opening the capsules with mechanical friction or pressure, as shown in Figure 5 The polyurea / polyurethane microcapsules according to the present application show a significant improvement in the sensory performance (perfume release) of at least 1.5 times, preferably at least 1.75 times, even more preferably at least 2 times compared to the prior art capsules.

[0402] With increasing degree of crosslinking, i.e. with increasing polyisocyanate content, the stability of the microcapsules increases, but at the same time the biodegradability of the capsule shell decreases, as shown in the examples. Figure 6 The correlation of microcapsule stability, performance and biodegradability with the degree of crosslinking is shown in general. For example, in the case of very stable microcapsules, the performance, e.g. the sensory performance, is lower due to the reduced number of microcapsules which rupture and release the active substance by means of friction, pressure, etc.

[0403] The polyurea / polyurethane microcapsules according to the present application have a maximum of 60% less polyisocyanate content compared to the prior art polyurea / polyurethane microcapsules without a loss or absence of stability of the microcapsules or a loss in the loading of the active substance to be encapsulated, as shown in the following examples. The isocyanate no longer serves as the main material of the capsule shell or capsule wall compared to the prior art microcapsules, but only as a crosslinker for the amino acid and the other main components of the capsule shell, such as the protective colloid and the hydroxyl donor. The absolute polyisocyanate content of the microcapsules described herein corresponds to only 1 / 60 of the entire capsule comprising the active substance. Assuming that the raw materials are stoichiometrically reacted, it can be assumed that exactly 1 / 5 of the wall material consists of polyisocyanate in 100% of the wall material and, due to the small amount it represents, can only be considered as a crosslinker.

[0404] On the one hand due to the lower polyisocyanate content in the capsule shell or capsule wall and on the other hand due to the use of a release agent, the microcapsules according to the present application have a better biodegradability than the prior art capsules. The microcapsules prepared according to the present application using a release agent have a significantly better biodegradability, as shown in the subsequent examples.

[0405] Biodegradability is the ability of an organic material to be degraded into water, carbon dioxide (CO2) and biomass under defined temperature, oxygen and humidity conditions in the presence of microorganisms or fungi within a defined period of time.

[0406] According to OECD 301 F, microcapsules are considered immediately biodegradable if more than 60% of the wall material is degraded after 28 days.

[0407] The biodegradability of the microcapsules according to the present application is according to OECD 301 F after 28 days > 20%, preferably > 50%, even more preferably > 70%, most preferably > 90%.

[0408] Furthermore, the microcapsules of the present application are a versatile capsule which can be used to encapsulate a broad range of fragrances or flavorings, even fragrances or flavorings having aldehyde, carboxylic acid or ester functions, according to the current state, thus there is no limitation to individual active substances.

[0409] Due to their advantageous properties, in particular their stability and the targeted release of the active substances, the microcapsules according to the present application are suitable for a broad range of applications, in particular for household products, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters, fragrance lotions and fragrance enhancers, cosmetics, personal care products, agricultural products, pharmaceutical products, paper printing inks and the like.

[0410] Therefore, the present application relates in another aspect to the use of the biodegradable polyurea / polyurethane microcapsules according to the present application or the dispersion of the polyurea / polyurethane microcapsules according to the present application for the manufacture of household products, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters in liquid or solid form, fragrance lotions or fragrance enhancers, cosmetics, personal care products, agricultural products, pharmaceutical products, paper printing inks and the like.

[0411] Finally, the present application relates to household products, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters, fragrance lotions or fragrance enhancers, cosmetics, personal care products, agricultural products, pharmaceutical products, paper printing inks and the like, comprising the biodegradable polyurea / polyurethane microcapsules according to the present application or the dispersion of the polyurea / polyurethane microcapsules according to the present application.

[0412] Examples

[0413] The biodegradable polyurea / polyurethane microcapsules according to the present application and their beneficial properties will be described in more detail by the following examples.

[0414] Example 1 - Comparison of wall materials

[0415] Table 1:

[0416]

[0417] *) all contents relate to the complete microcapsule including the oil

[0418] The microcapsules according to the present application have a significantly lower polyisocyanate content, which can be reduced by up to 60%. In contrast to the prior art microcapsules, the isocyanate is no longer the main material and only serves as a crosslinker for the amino acid and other ingredients of the capsule material.

[0419] Example 2 - Capsule stability

[0420] The following stability data refer to tests at 40°C using commercially available formulations, such as a fragrance booster or a fabric softener.

[0421] The selected capsules are prior art capsules, whose capsule wall can be attributed entirely to a polyurea network. The preparation of these capsules usually does not use a catalyst and the synthesis is carried out at a pH value of 9. Polyvinyl alcohol is used as protective colloid.

[0422] The slurry is placed in isopropanol for 30 seconds and the free oil is determined. The oil content is then determined using SPME.

[0423] Example 1 - Relationship of capsule stability to release agent

[0424] The behavior of the free oil is determined by the change of the release agent. The microcapsules according to the present application are prepared by using an isocyanate mixture consisting of hexamethylene diisocyanate and 4,4'-diphenylmethane diisocyanate in a ratio of 75:25. In addition, lysine*HCI is used as the first amino acid, glycerol as the hydroxyl donor and arginine as the second amino acid. DABCO is used as catalyst and modified starch as protective colloid. TomCap is used as the phase to be encapsulated. The waxes used are listed in the table below. The starch used is present in the form of a succinate.

[0425] Table 2:

[0426] Wax Free oil / % No wax 0.61 Beeswax 0.09 Carnauba wax 0.23 Rice bran wax 0.23 Sunflower wax 0.27

[0427] It is apparent that the use of waxes increases the resistance to the extraction solvent. The capsules are considered stable when the free oil is <1%. The lower the free oil content, the more stable the capsules.

[0428] Example 2 - Relationship of capsule stability to polyisocyanate composition (comparison of a single polyisocyanate and a combination of two different polyisocyanates)

[0429] The microcapsules according to the present application are prepared using different single polyisocyanates or a combination of two different polyisocyanates, guanidinium carbonate, polyvinyl alcohol as protective colloid and TomCap as the fragrance oil:

[0430] Table 3:

[0431]

[0432]

[0433] The use of a combination of two different isocyanates resulted in two times more stable microcapsules than the single isocyanate system. Therefore, it is preferred to use a mixture of two different isocyanates.

[0434] Example 3 - Relationship between capsule stability and polyisocyanate composition (comparison of aliphatic-aliphatic polyisocyanate mixture and aliphatic-aromatic polyisocyanate mixture)

[0435] The microcapsules according to the present application using aliphatic-aliphatic polyisocyanate mixtures and aliphatic-aromatic polyisocyanate mixtures were prepared as follows:

[0436] Aliphatic-aliphatic polyisocyanate mixture: pentamethylene diisocyanate and hexamethylene diisocyanate in a ratio of 50:50.

[0437] Aliphatic-aromatic isocyanate mixture: hexamethylene diisocyanate and 4,4'-diphenylmethane diisocyanate in a ratio of 75:25.

[0438] Furthermore lysine*HCI was used as the first amino acid, glycerol as the hydroxyl donor and arginine as the second amino acid. DABCO was used as catalyst and modified starch as protective colloid. TomCap was used as the encapsulating phase. Beeswax was used as the wax. The starch used was present in the form of a succinate.

[0439] Table 4:

[0440] Isocyanate mixture Free oil / % Aliphatic-aliphatic 0.49 Aliphatic-aromatic 0.09

[0441] The free oil in both samples was significantly below 1%, therefore both capsules were considered stable. The microcapsules made from the aliphatic-aliphatic polyisocyanate mixture were as stable as the microcapsules made from the aliphatic-aromatic polyisocyanate mixture.

[0442] Example 3 - Biodegradability and free oil in relation to the amount of crosslinker (isocyanate)

[0443] The free oil content was determined as described above.

[0444] The biodegradability according to OECD 301 F was determined as follows: the degradation of the wall material in unacclimated bacteria was measured by pressure respiration (oxygen consumption).

[0445] Table 5:

[0446]

[0447] With decreasing amounts of isocyanate (crosslinker) the biodegradability increases. In this case, surprisingly, there is a minimal increase in free oil, which makes the capsules appear to be stable.

[0448] Example 4 - Biodegradability comparison with and without release agent

[0449] Table 6:

[0450]

[0451] *) All contents of the complete microcapsule including oil

[0452] *) Capsule content including oil

[0453] The capsules according to the application show a biodegradability of 96%, so the wall material can be considered immediately biodegradable.

[0454] Example 6 - Biodegradability comparison with sodium sulfate and toxicity control

[0455] The biodegradability of the wall material was tested according to OECD 301 F using the microcapsules according to the application of application example 5. For this, sodium benzoate was used as a method control and a mixture of the inventive microcapsules and sodium benzoate as a toxicity control.

[0456] Test replicates 1 and 2 = capsules according to the application

[0457] Method control replicates 1 and 2 = sodium sulfate

[0458] Toxicity control = combination of capsules according to the application and sodium sulfate to control toxicological effects

[0459] The test results are shown in Figure 4 .

[0460] The capsules according to the application show an average biodegradability of 96% for both samples, so the wall material can be considered immediately biodegradable. The toxicity control also shows degradability, proving that the wall material of the capsules according to the application is not persistent.

[0461] Example 7 - Biodegradability comparison with and without wax

[0462] The microcapsules according to the present application were prepared by using an isocyanate mixture consisting of hexamethylene diisocyanate and 4,4'-diphenylmethane diisocyanate in a ratio of 75:25. Furthermore, lysine HCI was used as the first amino acid, glycerol as the hydroxyl donor and arginine as the second amino acid. DABCO was used as catalyst and modified starch as protective colloid. The wall material was then separated using a centrifuge rotary evaporator and a vacuum drying cabinet. Ethyl acetate was used as the phase to be encapsulated. The waxes used are listed in the table below. The starch used was present in the form of a succinate.

[0463] Table 7:

[0464] Wax Biodegradability / % after 28 days according to OECD 301 F No wax 12 Beeswax 96 Sunflower wax 72

[0465] Both capsules were considered biodegradable according to OECD 301 F by the use of waxes. Surprisingly, the use of waxes increased the biodegradability disproportionately, although the amount of wax was small.

[0466] Example 8 - Sensory test

[0467] For the sensory evaluation, the microcapsules according to the present application were compared with a microcapsule of the prior art, i.e. based on a polyurea / polyurethane structure without the use of a release agent.

[0468] The microcapsules were prepared with hexamethylene diisocyanate and 4,4'-diphenylmethane diisocyanate in a ratio of 75:25. Furthermore, lysine HCI was used as the first amino acid, glycerol as the hydroxyl donor and arginine as the second amino acid. DABCO was used as catalyst and modified starch as protective colloid; beeswax as release agent.

[0469] The sensory evaluation was as follows: The above microcapsules were added to a fabric softener at an oil concentration of 0.2 wt.-% each, and then rinsed. The odor was emitted on a mixed fiber cloth of cotton and polyester.

[0470] 12 subjects rated the intensity of the odor (ranking) of the mixed fiber cloth after washing, the rating going from 1 (no odor) to 9 (very strong odor). The release of the fragrance was in this case performed in three steps. The first step described the odor of the untreated cloth. The second step described the odor of the cloth after gentle rubbing; for this, the cloth was gently mechanically treated, rubbing it back and forth between the two hands several times, thus breaking the capsules. The third step described the odor after strong rubbing of the cloth, thus breaking the capsules.

[0471] The microcapsules according to the present application had significantly better performance, as shown in Figure 5 This can be attributed to the specific modification of the system, as by the deposition of different polymers through the crosslinking units and the use of a separating agent, a defined shell structure was constructed, which gave the capsules better adhesion and odor.

Claims

1. A method for preparing biodegradable polyurea / polyurethane microcapsules, the method comprising the following steps in sequence: (a) Performing the first polymerization and / or crosslinking step, including: (a1) Provides 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) Provides an external aqueous phase, including at least one protective colloid; (a3) Mix the internal non-aqueous phase and the external aqueous phase to obtain an oil-in-water emulsion; (a4) Add at least one first amino acid or amino acid hydrochloride and a catalyst; (b) A second polymerization and / or crosslinking step is carried out by adding at least one hydroxyl donor; (c) Obtaining a microcapsule dispersion by adding at least one second amino acid to carry out a third polymerization and / or crosslinking step; (d) Curing the microcapsule dispersion at a temperature of at least 60°C for at least 60 minutes; (e) Add at least one release agent and place the release agent in the microcapsule shell; (f) Post-curing the polyurea microcapsules obtained in step (e).

2. The method according to claim 1, wherein the external aqueous phase comprises at least one protective colloid and an emulsifier.

3. The method according to claim 1, wherein step (c) comprises obtaining a microcapsule dispersion by adding at least one second amino acid and performing a third polymerization and / or crosslinking step at a temperature of at least 60°C.

4. The method according to claim 1, wherein the method further comprises step (g): separating the microcapsules from the microcapsule dispersion.

5. The method according to claim 4, wherein step (g) further comprises: The microcapsules are dried.

6. The method according to claim 1, wherein the at least one polyisocyanate having two or more isocyanate groups is selected from: aliphatic, alicyclic, hydroaromatic, aromatic or heterocyclic polyisocyanates, their substituted products, and mixtures of the above compounds.

7. The method according to claim 6, wherein the at least one polyisocyanate comprises two aliphatic polyisocyanates or one aliphatic and one aromatic polyisocyanate.

8. The method of claim 6, wherein the at least one polyisocyanate comprises polyisocyanates with alternating monomers, oligomers, or polymers having different chain lengths.

9. The method according to any one of claims 1 to 8, characterized in that, The at least one lipophilic active substance to be encapsulated is selected from: fragrances, flavorings, coolants, TRPV1 and TRPV3 modifiers, food additives, cosmetic active substances, pharmaceutical active substances, dyes, dye precursors; agricultural chemicals, luminescent inks, optical brighteners, solvents, waxes, silicone oils, lubricants, paper printing coating substances, and mixtures of two or more of the above active substances.

10. The method according to claim 9, characterized in that, The at least one lipophilic active substance to be encapsulated is selected as an insecticide.

11. The method according to claim 9, characterized in that, The at least one lipophilic active substance to be encapsulated is selected as a suicide biological agent.

12. The method according to claim 9, characterized in that, The at least one lipophilic active substance to be encapsulated is selected from sterilizing agents.

13. The method according to claim 9, characterized in that, The at least one lipophilic active substance to be encapsulated is selected from substances in the repellent group.

14. The method according to any one of claims 1 to 8, characterized in that, The at least one lipophilic active substance to be encapsulated is selected from flavorings or seasonings having aldehyde, carboxylic acid, or ester functional groups.

15. The method according to any one of claims 1 to 8, characterized in that, The protective colloid is selected from: -Polyols, - Polyvinylpyrrolidone, vinyl maleate copolymer, sodium lignosulfonate, maleic anhydride / styrene copolymer, ethylene / maleic anhydride copolymer, ethylene oxide copolymer, propylene oxide and polyethoxysorbate ester, sodium dodecyl sulfate -Animal and plant polymers, And mixtures of the above compounds.

16. The method according to claim 15, characterized in that, The polyols are selected from diols, triols, polyvinyl alcohol and polyvinyl alcohol derivatives, polyphenols, polysaccharides and glucose.

17. The method according to claim 16, characterized in that, The diol is selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol and 1,2-dodecanediol.

18. The method according to claim 16, characterized in that, The triol is selected from glycerol and its ethoxylated and propoxylated products, and trimethylolpropane and its ethoxylated and propoxylated products.

19. The method according to claim 16, characterized in that, The polyvinyl alcohol derivative is selected from ammonium or sulfonate-functionalized polyvinyl alcohol.

20. The method according to claim 16, characterized in that, The polyphenols are selected from 1,3,5-trihydroxybenzene.

21. The method according to claim 16, characterized in that, The polysaccharide is selected from starch or chemically, mechanically and / or enzymatically modified starch, and cellulose derivatives.

22. The method according to claim 21, characterized in that, The cellulose derivative is selected from hydroxyethyl cellulose or carboxymethyl cellulose.

23. The method according to claim 22, characterized in that, The hydroxyethyl cellulose is selected from quaternized hydroxyethyl cellulose.

24. The method according to claim 15, characterized in that, The animal and plant polymers are selected from gum arabic, proteins, gelatin, mastic resin, shellac, lignin, chitosan, and saponins.

25. The method according to any one of claims 1 to 8, characterized in that, The protective colloid is used in combination with starch.

26. The method according to any one of claims 1 to 8, characterized in that, The at least one first amino acid is selected from: arginine, histidine, lysine, tryptophan, ornithine, arginine hydrochloride, histidine hydrochloride, lysine hydrochloride, tryptophan hydrochloride, ornithine hydrochloride, and mixtures thereof.

27. The method according to any one of claims 1 to 8, characterized in that, The catalyst is selected from: diazabicyclo[2.2.2]octane, bismuth catalyst, tin catalyst and mixtures thereof.

28. The method according to any one of claims 1 to 8, characterized in that, The hydroxyl donor is a polyol having two or more hydroxyl groups.

29. The method according to claim 28, characterized in that, The polyol having two or more hydroxyl groups is selected from glycerol, propylene glycol, 1,3,5-trihydroxybenzene, starch, modified starch, cellulose derivatives, or gum arabic or mixtures thereof.

30. The method according to claim 29, characterized in that, The cellulose derivative is selected from hydroxyethyl cellulose or carboxymethyl cellulose.

31. The method according to claim 30, characterized in that, The hydroxyethyl cellulose is selected from quaternized hydroxyethyl cellulose.

32. The method according to any one of claims 1 to 8, characterized in that, At least one second amino acid is selected from: arginine, histidine, aspartic acid, lysine, glycine, alanine, proline, cysteine, glutamine, leucine, serine, tryptophan, valine, threonine, ornithine, and mixtures thereof.

33. The method according to any one of claims 1 to 8, characterized in that, The at least one release agent is selected from: - Long chains with 12 to 30 carbon atoms, aliphatic, straight or branched, saturated or unsaturated carboxylic acids; - Long-chain, aliphatic, straight-chain or branched, saturated or unsaturated primary alcohols with 12 to 30 carbon atoms; -Esters of long-chain aliphatic saturated carboxylic acids having 12 to 30 carbon atoms and long-chain aliphatic primary alcohols having 12 to 30 carbon atoms; and -Animal and plant waxes; And a mixture of the above-mentioned release agents.

34. The method according to claim 33, characterized in that, The long-chain, aliphatic, straight-chain or branched, saturated or unsaturated carboxylic acids having 12 to 30 carbon atoms are selected from lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, arachidic acid, teicoic acid, behenic acid, limonic acid, ceric acid, linoleic acid, and beeswax acid; myristone acid, palmitoleic acid, heptadecanoic acid, octadecenoic acid, oleic acid, transoleic acid, isoleic acid, cod oleic acid, cetearic acid, cetene, erucic acid, nervonic acid, linoleic acid, α-linolenic acid, γ-linolenic acid, calendulatic acid, punicic acid, α-tung oil acid, β-tung oil acid, octadecanoic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, docosapentaenoic acid, docosahexaenoic acid, and docosahexaenoic acid; phytic acid.

35. The method according to claim 33, characterized in that, The long-chain, aliphatic, straight-chain or branched, saturated or unsaturated primary alcohol having 12 to 30 carbon atoms is selected from lauryl alcohol, myristyl alcohol, palmitol, heptadecanol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, lignoceryl alcohol, wax alcohol, linoleic alcohol and beeswax alcohol; palm oil alcohol, oleyl alcohol, transoleyl alcohol, linoleic alcohol, γ-linolenic acid alcohol.

36. The method according to claim 33, characterized in that, The esters of the long-chain aliphatic saturated carboxylic acids having 12 to 30 carbon atoms and the long-chain aliphatic primary alcohols having 12 to 30 carbon atoms are selected from lauryl palmitate, myristyl palmitate, cetyl arachidate, and stearyl behenate.

37. The method according to claim 33, characterized in that, The animal and plant waxes are selected from wool wax, Chinese wax, beeswax, sunflower seed wax, rice bran wax, carnauba wax, soybean wax, jojoba oil, cork wax, cotton wax, linseed wax, peat wax, rose wax, jasmine wax, as well as myrtle wax, fig wax, and berry wax.

38. A biodegradable polyurea / polyurethane microcapsule or microcapsule dispersion obtainable by the method of any one of claims 1 to 37.

39. A biodegradable polyurea / polyurethane microcapsule, comprising: (i) a core, comprising at least one hydrophobic agent; and (ii) Capsule shell, including -In the presence of a protective colloid, the reaction product of polymerization and / or crosslinking of at least one polyisocyanate having two or more isocyanate groups with at least one first amino acid or amino acid hydrochloride, further polymerization and / or crosslinking with at least one hydroxyl donor, and further polymerization and / or crosslinking with at least one second amino acid; and - At least one release agent.

40. The biodegradable polyurea / polyurethane microcapsule according to claim 39, characterized in that, The capsule shell includes (α) A first crosslinking matrix or a first crosslinking unit consisting of the polymerization and / or crosslinking of at least one polyisocyanate having two or more polyisocyanate groups with at least one protective colloid and at least one first amino acid; (β) A second crosslinking matrix or second crosslinking unit consisting of crosslinking of at least one polyisocyanate having two or more polyisocyanate groups and at least one hydroxyl donor; (γ) A third crosslinking matrix or third crosslinking unit consisting of at least one polyisocyanate having two or more polyisocyanate groups and at least one second amino acid; and (δ) At least one release agent.

41. The biodegradable polyurea / polyurethane microcapsules according to any one of claims 38-40, characterized in that, It exhibits ≥20% biodegradability and / or ≤0.3% free hydrophobic agent content after 28 days according to the OECD 301F manotropic respiration method.

42. Use of a biodegradable polyurea / polyurethane microcapsule according to any one of claims 38-41 or a polyurea / polyurethane microcapsule dispersion according to claim 38 for the manufacture of household products, textile care products, detergents, fabric softeners, cleaning agents, fragrance enhancers, fragrance washes or fragrance in liquid or solid form, cosmetics, personal care products, fragrance compositions, agricultural products, pharmaceutical products or paper printing coatings.

43. Household products, textile care products, detergents, fabric softeners, cleaning agents, fragrance enhancers, fragrance washes and fragrance intensifiers, cosmetics, personal care products, fragrance compositions, agricultural products, pharmaceutical products or paper printing coatings, including biodegradable polyurea / polyurethane microcapsules according to any one of claims 38-41 or polyurea / polyurethane microcapsule dispersions according to claim 38.

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