Biodegradable polyurea / polyurethane microcapsules

Abstract

The present invention relates to a method for manufacturing biodegradable polyurea / polyurethane microcapsules having improved biodegradability compared to microcapsules of the prior art, preferably fragrance-containing polyurea / polyurethane microcapsules. Furthermore, the present invention relates to biodegradable polyurea / polyurethane microcapsules comprising at least one lipophilic active ingredient obtainable by the method according to the present invention. In another aspect, the invention described herein relates to the use of such microcapsules or microcapsule dispersions comprising such microcapsules according to the present invention for the manufacture of household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters, fragrance lotions or fragrance enhancers, cosmetics, personal care products, crops, pharmaceutical products or printing coatings for paper. Ultimately, the present invention relates to consumer products comprising such microcapsules or microcapsule dispersions.

Description

Technology Field

[0001] The present invention relates to a method for producing biodegradable polyurea / polyurethane microcapsules that surround at least one lipophilic active ingredient, preferably fragrance- or aroma-containing polyurea / polyurethane microcapsule, having a balance of biodegradability, stability, and performance compared to microcapsules of the prior art. Additionally, the present invention relates to biodegradable polyurea / polyurethane microcapsules comprising at least one lipophilic active ingredient obtainable by the method of the present invention. In another aspect, the invention described herein relates to the use of such microcapsules or microcapsule dispersions comprising microcapsules according to the present invention for the manufacture of household goods, textile care products, detergents, fabric softeners, cleaning products, fragrance boosters, fragrance lotions or fragrance enhancers, cosmetics, personal care products, crops, pharmaceutical products, or printing coatings for paper. Ultimately, the present invention relates to consumer products comprising such microcapsules or microcapsule dispersions. Background Technology

[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 high-density, permeable, or semipermeable polymer wall material. During manufacturing, after emulsification and coacervation or interfacial polymerization, the polymer of the starting component is deposited and immobilized in the encapsulating material. The core is also referred to as the inner phase. Designations such as outer phase, shell, or coating are also used for the wall. The diameter of the microcapsules typically varies in the range of 1 to 1000 μm. The wall thickness is typically 0.5 to 150 μm. Loading is typically possible at 25 to 95 wt%, but loading at 1 to 99 wt% is also possible.

[0003] The purpose of encapsulation is, above all, to protect the encapsulated substance or active ingredient, release it at a specific time, convert a liquid into a manageable powder form, delay the loss of volatile components (e.g., in the case of fragrances or flavorings), prevent premature chemical reactions with other mixture components, or ensure better handling before or during processing. Lipophilic or hydrophobic active ingredients, such as fragrances or flavorings, can be easily incorporated into numerous different application formulations through encapsulation.

[0004] The contents of microcapsules can be released in various ways, specifically based on one of the mechanisms described below: 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] Various shell materials for the production of microcapsules are known. The shell may be composed of natural, semi-synthetic, or synthetic materials. Natural shell materials are, for example, gum arabic, agar, agarose, maltodextrin, alginic acid or its salts, for example, 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, but are not limited to, chemically modified cellulose, in particular cellulose esters and cellulose ethers, for example, cellulose acetate, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and carboxymethyl cellulose, and 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 manufacturing method, microcapsules with different characteristics in terms of diameter, size distribution, and physical and / or chemical properties are produced.

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

[0008] Polyurea microcapsules obtained by reacting two polyisocyanates with a polyamine are described, for example, in WO 2011 / 161229 or WO 2011 / 160733. According to WO 2011 / 161229 or WO 2011 / 160733, polyurea microcapsules are prepared in the presence of polyvinylpyrrolidone (PVP) as a protective colloid. WO 2012 / 107323 discloses polyurea microcapsules having a polyurea shell comprising a reaction product of a polyisocyanate with a guanazol (3,5-diamino)-1,2,4-triazole) and an amino acid in the presence of an anionic stabilizer or surfactant, such as anionic polyvinyl alcohol. EP 0 537 467 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 occur in an oil phase emulsified in a continuous aqueous phase, which is generally stabilized by a surfactant system such as polyvinyl alcohol or its carboxylated and sulfonated derivatives.

[0009] The aforementioned exemplary prior art delivery system possesses excellent stability, that is, the ability of the capsule to retain the active ingredient and thus prevent the loss of volatile components, and excellent performance, for example, fragrance release in the case of fragrance capsules.

[0010] However, the microcapsules of the aforementioned prior art have a disadvantage in that the polymer capsule wall or shell material requires a high polymer content to ensure sufficient stability and prevent excessive loss of the active ingredient. Additionally, microencapsulation introduces plastic into the environment, which can cause problems as "microplastics."

[0011] As plastic particles are subject to public criticism regarding their impact on the environment and social pressure regarding environmental aspects steadily increases, leading to a growing demand for bio-based and biodegradable solutions, microencapsulation is necessary to develop new materials to achieve the reduction of microplastics in the environment. Bio-based and biodegradable materials are the focus of this specification.

[0012] Against this backdrop, there is therefore a need to provide polyurea / polyurethane microcapsules that, on the one hand, possess excellent stability and release characteristics for their respective applications, and on the other hand, are mostly or nearly completely biodegradable.

[0013] However, this work of using biodegradable materials to reduce the amount of microplastics in the environment is not trivial in the case of microencapsulation, because the desired functions of microcapsules, such as positive secondary properties like olfactory properties, high stability, and toxicological stability, conflict with the requirements for rapid biodegradability in many applications.

[0014] Producing microcapsules that offer both good stability and active ingredient release is particularly difficult. The capsule's ability to retain active ingredients, and thus prevent the loss of volatile components, depends particularly on the capsule's stability within the product base. However, capsules with exceptional stability do not automatically exhibit superior biodegradability.

[0015] As the degree of crosslinking increases, the stability of microcapsules increases, but at the same time, the ability to biodegrade the capsule shell decreases. In the case of highly stable microcapsules, performance—such as sensory performance—deteriorates as the number of microcapsules that break and release active ingredients decreases due to pressure, friction, etc. If they are too unstable, they are destroyed during storage, resulting in poor performance.

[0016] Against this background, the present invention is based on the complex problem of providing a method for manufacturing microcapsules that, on the one hand, can provide microcapsules having a lower polymer content that exhibit high stability and excellent release behavior of the encapsulated active substance and, where possible, biodegradable properties. The problem to be solved

[0017] Surprisingly, it was found that this challenge can be solved by producing polyurea / polyurethane microcapsules using amino acids and release agents that are self-embedded in the microcapsule shells. means of solving the problem

[0018] The current problem is resolved by the purpose of the independent patent claim. A preferred embodiment is derived from the wording of the dependent patent claim and the following description.

[0019] Accordingly, the first object of the present invention is to a method for manufacturing biodegradable polyurea / polyurethane microcapsules comprising the following steps in order:

[0020] (a) A step of performing a first polymerization and / or crosslinking step comprising the following:

[0021] (a1) providing an internal non-aqueous phase comprising at least one polyisocyanate having two or more isocyanate groups and at least one lipophilic active material encapsulated therein;

[0022] (a2) a step of providing an external aqueous phase comprising at least one protective colloid and optionally an emulsifier;

[0023] (a3) A step of mixing an internal non-aqueous phase and an external aqueous phase to obtain an oil-in-water emulsion;

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

[0025] (b) a step of performing a second polymerization and / or crosslinking step by adding at least one hydroxyl group donor;

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

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

[0028] (e) a step of adding at least one release agent and incorporating the release agent into the microcapsule shell;

[0029] (f) A step of post-curing the microcapsules obtained in step (f);

[0030] and optionally

[0031] (g) A step of separating microcapsules from a microcapsule dispersion and optionally drying the microcapsules or adding a thickener to adjust the viscosity of the microcapsule slurry.

[0032] The object of the present invention as described herein is also to provide a biodegradable polyurea / polyurethane microcapsule comprising at least one lipophilic active ingredient, prepared according to the method of the present invention.

[0033] Another aspect of the present invention is a biodegradable polyurea / polyurethane microcapsule comprising the following:

[0034] (i) a core comprising at least one hydrophobic agent; and

[0035] (ii) A capsule shell containing the following:

[0036] - A reaction product of the polymerization and / or crosslinking of at least one polyisocyanate having two or more isocyanate groups in the presence of at least one protective colloid having at least one first amino acid or amino acid hydrochloride, further polymerization and / or crosslinking with at least one hydroxyl group donor, and further polymerization and / or crosslinking with at least one second amino acid; and

[0037] - At least one release agent.

[0038] Finally, in another aspect, the present invention relates to the use of biodegradable polyurea / polyurethane microcapsules or dispersions of polyurea / polyurethane microcapsules according to the present invention for the manufacture of household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters, fragrance lotions or fragrance enhancers, cosmetics, personal care products, perfume compositions, crops, pharmaceutical products or printing coatings for paper, and consumer products made therefrom.

[0039] Surprisingly, in the production of microcapsules, a combination of targeted polymerization and / or crosslinking of a polyisocyanate having at least two isocyanate groups and a first amino acid or amino acid hydrochloride, subsequent polymerization and / or crosslinking with a hydroxyl group donor, and further polymerization and / or crosslinking with a second amino acid and / or the addition of a release agent and incorporation of the release agent into the microcapsule shell leads to stable microcapsules, thus ensuring efficient encapsulation of active substances and subsequent targeted release of these active substances, and at the same time, the microcapsules were found to exhibit excellent biodegradability due to bio-based and biodegradable building blocks such as amino acids and release agents.

[0040] By using amino acids and release agents, the polymer content of the capsule wall or capsule shell material can be reduced without affecting the stability of the microcapsule wall. Incorporating a release agent into the microcapsule shell promotes the biodegradability of the capsule wall or capsule shell material.

[0041] These and other aspects, features, and advantages of the present invention will be apparent to those skilled in the art from the study of the following detailed description and claims. In this regard, any feature from one aspect of the present invention may be used or substituted in other aspects of the present invention. The embodiments of this specification are illustrative and do not limit the present invention.

[0042] In this specification, the terms “at least one,” “not less than one,” or “one or more” refer to one or more, for example, 2, 3, 4, 5, 6, 7, 8, or more than 9.

[0043] The term "and / or" indicates that a connection exists or an alternative is provided.

[0044] Number examples given in the format "x to y" include the given values. If multiple base number ranges are provided in this format, all ranges created by combining different endpoints are also included. Brief explanation of the drawing

[0045] Figure 1 is an optical microscope image of a microcapsule according to the present invention. The microcapsule is prepared from hexamethylene diisocyanate and 4,4'-methyl diphenylene diisocyanate in a 75:25 ratio. Additionally, lysine*HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and arginine as the second amino acid. DABCO was used as a catalyst and modified starch was used as a protective colloid; beeswax was added as a release agent. Olympus BX51 was used for the optical microscope image. The indicated bar corresponds to 100 μm. FIG. 2 shows a diagram of the particle size distribution (d(0.5) value) of a microcapsule according to the present invention and a microcapsule of the prior art based on a polyurea / polyurethane structure without a release agent. The particle size distribution was determined using a MALVERN Mastersizer 3000. The calculation is based on Mie theory. FIG. 3 is a diagram showing the results of IR spectroscopic analysis of microcapsules according to the present invention and microcapsules of the prior art, i.e., microcapsules based on a polyurea / polyurethane structure without a release agent. The analysis was performed by attenuated total reflection (ATR) infrared spectroscopy. NB In FIG. 3, the decimal places of the absorption axis are indicated by dots instead of commas as decimal separators. Figure 4 is a diagram showing the biodegradability of microcapsules according to OECD 301 F compared with sodium benzoate and toxicity control (a mixture of microcapsules according to the present invention and sodium benzoate). FIG. 5 is a diagram showing the results of sensory evaluation of a microcapsule according to the present invention and a prior art microcapsule, i.e., a microcapsule based on a polyurea / polyurethane structure without a release agent. NB In FIG. 5, the decimal places of the intensity axis are indicated by dots instead of commas as decimal separators. Figure 6 is a diagram showing the general correlation between microcapsule stability, performance, and biodegradability as a function of the degree of crosslinking. Specific details for implementing the invention

[0046] In a first aspect, the present invention relates to a method for manufacturing biodegradable polyurea / polyurethane microcapsules, preferably a method for manufacturing fragrance capsules, the method comprising the following steps in order:

[0047] (a) A step of performing a first polymerization and / or crosslinking step comprising the following:

[0048] (a1) providing an internal non-aqueous phase comprising at least one polyisocyanate having two or more isocyanate groups and at least one lipophilic active material encapsulated therein;

[0049] (a2) a step of providing an external aqueous phase comprising at least one protective colloid and optionally an emulsifier;

[0050] (a3) A step of mixing an internal non-aqueous phase and an external aqueous phase to obtain an oil-in-water emulsion;

[0051] (a4) a step of adding at least one first amino acid or amino acid hydrochloride and a catalyst;

[0052] (b) a step of performing a second polymerization and / or crosslinking step by adding at least one hydroxyl group donor;

[0053] (c) A step of obtaining a microcapsule dispersion by performing a third polymerization and / or crosslinking step by adding at least one second amino acid, particularly at a temperature of at least 60°C;

[0054] (d) a step of curing the microcapsule dispersion at a temperature of at least 60°C for a period of at least 60 minutes;

[0055] (e) a step of adding at least one release agent and incorporating the release agent into the microcapsule shell;

[0056] (f) A step of post-curing the microcapsules obtained in step (f);

[0057] and optionally

[0058] (g) A step of separating microcapsules from a microcapsule dispersion and optionally drying the microcapsules or adding a thickener to adjust the viscosity of the microcapsule slurry.

[0059] In the context of the present invention, a microcapsule is understood as a microparticle having at least one active ingredient as a capsule shell or capsule wall and as a core material inside the capsule. The active ingredient is preferably a lipophilic or hydrophobic active ingredient. Such active ingredients are insoluble or sparingly soluble in water but readily soluble in fats and oils. The terms "microcapsule" or "capsule" and "lipophilic" or "hydrophobic" are used as synonyms in the present invention.

[0060] In the context of the present invention, the capsule shell or capsule wall is preferably composed of several crosslinking matrices or crosslinking units having different compositions during the production of microcapsules according to the present invention, and is produced by several method steps or method sequences, particularly the crosslinking step, thereby forming a three-dimensional network.

[0061] In the context of the present invention, a crosslinking matrix or crosslinking unit is a complex or network of starting components for constructing a microcapsule shell, which is formed by linear or three-dimensional polymerization and / or crosslinking between functional groups of the starting components and / or other components of the microcapsule shell and / or other components of the microcapsule shell embedded therein. Several crosslinking matrices may be crosslinked to one another by additional crosslinking in the process of the method according to the present invention and form a three-dimensional structure for forming a microcapsule shell or a microcapsule wall. The crosslinking unit or crosslinking matrix as a whole forms a capsule shell or a capsule wall.

[0062] In a much more preferred embodiment of the present invention, the capsule shell or capsule wall comprises at least a polyurea and polyurethane crosslinking matrix or crosslinking unit and a release agent incorporated into the capsule shell or capsule wall.

[0063] In the first step (a) of the method according to the present invention, a first polymerization and / or crosslinking (a) is performed. To this end, an internal non-aqueous phase (a1) is provided, which comprises at least one isocyanate or a polyisocyanate having two or more isocyanate groups and at least one lipophilic active material encapsulated therein.

[0064] The polyurea / polyurethane microcapsules according to the present invention are manufactured using at least one polyisocyanate.

[0065] The at least one isocyanate or the polyisocyanate having two or more isocyanate groups used in the method of the present invention for manufacturing biodegradable polyurea / polyurethane microcapsules has at least two isocyanate groups to form a polymer network by polymerization, which forms a capsule shell or a capsule wall.

[0066] Polyisocyanates are R-substituted organic derivatives (RN=C=O) of isocyanic acids (HN=C=O). Organic isocyanates are compounds in which an isocyanate group (-N=C=O) is bonded to an organic radical. Polyfunctional isocyanates or polyisocyanates are compounds containing at least two, namely 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200, or even more isocyanate groups (-N=C=O) in a molecule. Polyisocyanates having two isocyanate groups are also called diisocyanates.

[0067] Polyisocyanates can be classified as aliphatic, alicyclic, hydroaromatic, aromatic, or heterocyclic isocyanates or polyisocyanates. Additionally, the polyisocyanates according to the present invention may be linear or branched.

[0068] Polyisocyanates, especially aromatic polyisocyanates, are highly reactive compounds. The heavy addition reaction between polyisocyanates and diols or polyols is the basis of polyurethane chemistry, and the heavy addition reaction between polyisocyanates and amines is the basis of polyurea chemistry.

[0069] According to the present invention, at least difunctional, preferably multifunctional, polyisocyanates are used, that is, all aliphatic, alicyclic, and aromatic isocyanates are suitable as long as they have at least two reactive isocyanate groups.

[0070] Mixtures of aliphatic, alicyclic, hydroaromatic, aromatic, or heterocyclic polyisocyanates, their substitution products, and the aforementioned monomeric or oligomeric compounds are particularly preferred. Among the polyisocyanates specified above, aliphatic and / or aromatic compounds are preferably used.

[0071] In a preferred embodiment of the method according to the present invention, the polyisocyanates contain an average of 2 to 5 functional -N=C=O groups. These include, for example, aliphatic, alicyclic, and aromatic di-, tri-, and higher polyisocyanates.

[0072] Among the aforementioned polyisocyanates, diisocyanates and polyisocyanates having three functional -NC=O groups are particularly preferred and are therefore preferentially applied in embodiments of the present invention. A diisocyanate having the general structure O=C=NRN=C=O (where R represents an aliphatic, alicyclic, or aromatic radical) is preferably used. Preferably, the radical has five or more carbon atoms.

[0073] In a preferred embodiment of the method according to the present invention, at least one polyisocyanate having two or more isocyanate groups is selected from the group consisting of aliphatic polyisocyanates and / or aromatic polyisocyanates. In a much more preferred variation of the method according to the present invention, at least one polyisocyanate is a combination of two different aliphatic polyisocyanates or a combination of aliphatic and aromatic polyisocyanates.

[0074] Due to the number of functional groups, optimal cross-linking or networking of the capsule wall is achieved, providing microcapsules that exhibit excellent stability in consumer products as well as long-term slow release of the active ingredient.

[0075] In a preferred variation of the method according to the present invention, the polyisocyanate is an aliphatic polyisocyanate.

[0076] The term "aliphatic polyisocyanate" refers to any polyisocyanate molecule that is not aromatic. Additionally, 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, which are directly attached to a corresponding number of different carbon atoms of the same aliphatic molecule and to derivatives of such compounds.

[0077] An 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, may be linear, branched, or cyclic, and may have any substitutions including, for example, aliphatic substituents, aromatic substituents, one or more heteroatoms such as nitrogen, oxygen, phosphorus and / or sulfur, halogens such as fluorine, chlorine, bromine and / or iodine and / or other functional groups such as alkoxy groups.

[0078] The linear aliphatic polyisocyanate molecule is preferably selected from C2 to C20 linear alkyl, preferably C3 to C15 linear alkyl, C4 to C12 linear alkyl, C5 to C10 linear alkyl, C6 to C9 linear alkyl, or C7 to C8 linear alkyl. Preferably, the linear aliphatic molecule does not contain an aromatic structure.

[0079] The branched aliphatic polyisocyanate molecule is preferably selected from C2 to C20 branched alkyl, preferably C3 to C15 branched alkyl, C4 to C12 branched alkyl, C5 to C10 branched alkyl, C6 to C9 branched alkyl, and C7 to C8 branched alkyl.

[0080] The shorter the carbon chain of the polyisocyanate molecule, the faster the reaction rate compared to long-chain analogs.

[0081] The cyclic aliphatic polyisocyanate molecule comprises at least one, i.e., 1, 2, 3, 4, or more non-aromatic ring structure, and the ring structure itself preferably consists of only 1 carbon atom. Of course, the 1 carbon atom of the ring structure may have suitable substituents. At least one ring structure preferably consists independently of a 3, 4, 5, 6, 7, or 8-membered ring. Preferably, the cyclic aliphatic molecule comprises 2 to 20 carbon atoms, e.g., 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.

[0082] In a further variation of the method according to the present invention, the polyisocyanate is an aromatic polyisocyanate. The term “aromatic polyisocyanate” refers to any polyisocyanate compound in which two or more isocyanate groups are directly attached to an aromatic carbon atom and, for example, a phenyl, tolyl, xylyl, naphthyl, or diphenyl moiety is included as an aromatic component, as well as derivatives of such polyisocyanate compounds.

[0083] Aromatic polyisocyanates react much faster than aliphatic polyisocyanates, so they are preferably used in the method according to the present invention.

[0084] Linear, branched, or cyclic aliphatic or aromatic polyisocyanates may exist as monomers or polymers. Monomeric polyisocyanates are molecules that are not connected to other molecules, particularly by one or more crosslinking agents. Polymeric polyisocyanates comprise at least two monomers connected by one or more crosslinking agents. The at least two monomers do not necessarily have to be the same monomer but may be different. Polymeric polyisocyanates preferably comprise at least two monomers connected together by at least one crosslinking agent, i.e., at least 2, 3, 4, 5, 10, 20, 30, 40, 50, 100, or more monomers.

[0085] Linear, branched, or cyclic aliphatic or aromatic polyisocyanates preferably have a limited size / molecular weight, which allows for reactivity with one or more crosslinking agents. Examples of suitable molecular weights are preferably 100 g / mol to 5·10 4 g / mol, preferably 120 g / mol to 2·10 4 g / mol, 140 g / mol to 10 4 g / mol, 160 g / mol to 5·10 3 g / mol, 180 g / mol to 2·10 3g / mol, 200 g / mol to 10 3 It includes g / mol, 220 g / mol to 900 g / mol, 240 g / mol to 800 g / mol, 260 g / mol to 700 g / mol, 280 g / mol to 600 g / mol, 300 g / mol to 500 g / mol, 320 g / mol to 450 g / mol, or 340 g / mol to 400 g / mol.

[0086] Any number of different linear, branched, and / or cyclic aliphatic and / or aromatic polyisocyanates may 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 cyclic aliphatic polyisocyanates are used.

[0087] Preferably, derivatives of linear, branched, and / or cyclic aliphatic polyisocyanates are used. As used herein, derivatives are understood in the broadest sense as compounds derived from a compound by a chemical reaction. Examples of derivatives include oligomers and / or adducts of the aforementioned linear or branched aliphatic polyisocyanates. Preferred oligomers are biuret, isocyanurate, urethdione, and aminooxadiazinedione, and preferred adducts are trimethylolpropane adducts. These oligomers / adducts are well known in the prior art and are disclosed, for example, in US 4855490 A or US 4144268 A.

[0088] Preferably, the aliphatic polyisocyanate exists only in monomeric and / or dimeric forms (as isocyanate) or oligomeric forms.

[0089] Derivatives of linear, branched, or cyclic polyisocyanates and / or mixtures thereof can also be obtained by reacting polyisocyanates with polyalcohols (e.g., glycerol), polyamines, or polythiols (e.g., dimercaprol).

[0090] The isocyanate compounds defined above specifically include various isomers (if present) alone or in combination. For example, methylenebis(cyclohexyl isocyanate) (H12MDI) includes 4,4'-methylenebis(cyclohexyl isocyanate), 2,4'-methylenebis(cyclohexyl isocyanate), and / or 2,2'-methylenebis(cyclohexyl isocyanate).

[0091] Exemplary aliphatic polyisocyanates include commercially available ones, such as BAYHYDUR N304 and BAYHYDUR N3Q5, 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, Pennsylvania.

[0092] According to another preferred variant of the present invention, the linear or branched aliphatic polyisocyanate is selected from the group consisting of pentamethylene diisocyanate (PDI, e.g., Stabio D-370N or D-376N of Mitsui Chemicals Inc., Japan), hexamethylene diisocyanate (HDI), ethyl ester lysine triisocyanate, lysine diisocyanate ethyl ester, and derivatives thereof, preferably each said derivative comprises more than one isocyanate group and optionally further comprises one or more groups from the group consisting of biuret, isocyanurate, urethdione, iminooxadiazinedione, and trimethylolpropane adducts, or said cyclic aliphatic polyisocyanate is composed of isophorone diisocyanate (IPDI) and 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI, e.g., Takenate). Selected from the group consisting of 600 Mitsui Chemicals Inc., Japan), 1,2-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanato-methyl)cyclohexane, methylenebis(cyclohexyl isocyanate) (H12MDI) and derivatives thereof, preferably each of said derivative comprises more than one isocyanate group and optionally further comprises one or more groups selected from the group consisting of biuret, isocyanurate, urethdione, iminooxadiazinonion, and trimethylolpropane adducts (e.g., TMP adducts) of H6XDI, particularly Takenate D-120N of Mitsui Chemicals Inc., Japan).

[0093] Aliphatic polyisocyanates obtained from renewable sources, such as PDI (Stabio D-370N or D-376N from Mitsui Chemicals Inc. of Japan), are particularly preferred. It has been found that these aliphatic polyisocyanates obtained from renewable sources do not affect the quality / characteristics of the core-shell capsule.

[0094] Other suitable commercially available polyisocyanates include LUPRANAT M20 (BASF) (where average n is 0.7); PA PI 27 (Dow Chemical) (where average n is 0.7); MONDUR MR (Bayer) (where average n is 0.8); MONDUR MR Light (Bayer) (where average n is 0.8); MONDUR 489 (Bayer) (where average n is 1.0); poly-[(phenyl isocyanate)-co-formaldehyde (Aldrich Chemical, Milwaukee, WI), and other isocyanate monomers such as DESMODUR N3200 (Bayer) and TAKENATE D1 10-N (Mitsui Chemicals Corporation, Rye Brook, NY). Other representative polyisocyanates include polyisocyanates named TAKENATE D-1 10N (Mitsui), DESMODUR L75 (Bayer), and DESMODUR IL (Bayer).

[0095] In a preferred embodiment, the polyisocyanate used in the manufacture of the polyurea / polyurethane microcapsule according to the present invention is the sole polyisocyanate component, that is, used without mixing with any other different polyisocyanate components.

[0096] Examples of monomeric polyisocyanates that can be used according to the present invention and contain at least two polyisocyanate groups are as follows:

[0097] Ethylene diisocyanate, trimethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethyl 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, mixture of 1,3-phenylene diisocyanate and 1,4-phenylene diisocyanate, p-phenylene diisothiocyanate, xylylene-1,4-diisothiocyanate, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, A mixture of 2,4-toluylene diisocyanate and 2,6-toluylene diisocyanate, xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate and a mixture of xylylene-1,4-diisocyanate and xylylene-1,3-diisocyanate, 2,4-hexahydrotoluylene diisocyanate, 2,6-hexahydrotoluylene diisocyanate, a mixture of 2,4-hexahydrotoluylene diisocyanate and 2,6-hexahydrotoluylene diisocyanate, hexahydro-1,3-phenylene diisocyanate, hexahydro-1,4-phenylene diisocyanate, and hexahydro-1,4-phenylene diisocyanate of A mixture, 1,3-diisocyanatobenzene, 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, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, triphenylmethane-4,4',4'-triisocyanate, toluene-2,4,6-triisocyanate, dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate, or a mixture of the aforementioned compounds.

[0098] As a polymerizable compound containing at least two polyisocyanate groups, diisocyanates and polyisocyanates produced on a large scale, for example, TDI: toluylene diisocyanate (a mixture of isomers of 2,4- and 2,6-toluylene diisocyanates in an 80:20 ratio), HDI: hexamethylene diisocyanate-(1,6), IPDI: isophorone diisocyanate, or DMDI: diphenylmethane-4,4'-diisocyanate are preferred.

[0099] Other particularly preferred monomeric polyisocyanate compounds are as follows: 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-polyisocyanato-3,3,5-trimethyl-5-polyisocyanatomethylcyclohexane (isophorone diisocyanate), 4,4'-diisocyanatodicyclohexylmethane, 2,4- and 2,6-diisocyanatomethylcyclohexane, and mixtures thereof. In principle, aromatic polyisocyanates, for example, toluylene diisocyanate or 4,4'-diisocyanatodiphenylmethacin may also be used.

[0100] Other specific examples of diisocyanates include, for example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), hydrogenated MDI (H12MDI), xylylene diisocyanate (XDI), tetramethylxylene diisocyanate (TMXD1), 4,4'-diphenyldimethylmethane diisocyanate, di- and tetraalkyldiphenylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, isomers of toluylene diisocyanate (TDI), optionally in mixtures, 1-methyl-2,4-diisocyanatocyclohexane, 1,6-diisocyanato-2,2,4-trimethylhexane. It includes 1,6-diisocyanato-2,4,4-trimethylhexane, 1-isocyanatomethyl-3-isocyanato-1,5,5-trimethylcyclohexane, chlorinated and brominated diisocyanates, phosphorus-containing diisocyanates, 4,4'-diisocyanatophenylperfluoroethane, tetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate (HDI), dicyclohexylmethane diisocyanate, cyclohexane-1,4-diisocyanate, ethylene diisocyanate, phthalate bisisocyanate ethyl ester, and also polyisocyanates having reactive halogen atoms, such as 1-chloromethylphenyl-2,4-diisocyanate-1,2-br 3,3-bischloromethyl ether-4,4'-diphenyl diisocyanate.

[0101] Surprisingly, it was found that using long-chain aliphatic diisocyanates, especially those having 6, 7, 8, 9, 10 or more carbon atoms, results in the formation of a more stable capsule shell or capsule wall.

[0102] In a particularly preferred embodiment, the internal non-aqueous phase comprises a mixture of two or more different polymerizable polyisocyanates, for example, polyisocyanates having different chain lengths capable of forming a copolymer.

[0103] Proportionally, derivatives of polyisocyanates containing groups such as uretdione, urethane, isocyanurate, biuret and / or allophanate, which can be prepared by modifying the aforementioned diisocyanate or mixture thereof by known methods, for example, may also be used in the method according to the present invention.

[0104] A combination of at least two different, preferably aliphatic polyisocyanates or a combination of at least one aliphatic and at least one aromatic polyisocyanate is particularly preferred.

[0105] In these combinations, various reaction rates of polyisocyanates are utilized. Aromatic polyisocyanates react significantly faster than aliphatic polyisocyanates, and in the case of short-chain aliphatic polyisocyanates, i.e., aliphatic polyisocyanates having 1 to 5 carbon atoms, preferably 3 to 5 carbon atoms, the reaction rate is higher compared to long-chain analogs.

[0106] Accordingly, in further preferred embodiments of the present invention, different aliphatic and / or aromatic polyisocyanates also have different chain lengths. In this context, long-chain polyisocyanates preferably have 6, 7, 8, 9, 10, 11, 12, 13, 14, 20, 25 or more carbon atoms, but more preferably 6 to 12 carbon atoms, particularly preferably 6 to 8 carbon atoms. Short-chain polyisocyanates mean polyisocyanates having 1 to 5 carbon atoms, preferably polyisocyanates having 3 to 5 carbon atoms.

[0107] According to the present invention, 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 thereof) or a combination of short-chain aliphatic polyisocyanates (C1, C2, C3, C4, C5) and long-chain aromatic polyisocyanates (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more thereof) or long-chain aliphatic polyisocyanates (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more thereof) is preferred. It is a combination of short-chain aromatic polyisocyanates and (or more) (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more).

[0108] In this context, it is particularly desirable to use a mixture of different aliphatic polyisocyanates having two or more isocyanate groups having a chain length of 1 to 12 carbon atoms, preferably 3 to 8 carbon atoms, particularly preferably 4 to 7 carbon atoms, for the production of biodegradable microcapsules according to the present invention.

[0109] Aliphatic polyisocyanates are particularly desirable in this context due to their chemical relationship with bio-based systems. For example, lysine and 1,5-diisocyanatopentane both exhibit the same degradation product, 1,5-diaminopentane, making them particularly suitable for use in the production of bio-based and biodegradable microcapsules with environmental considerations in mind.

[0110] The first embodiment comprises a mixture of long-chain and short-chain diisocyanates in any mixing ratio. Preferably, the mixing ratio of long-chain diisocyanate to short-chain diisocyanate is in the range of 4:1 to 1:4, particularly preferably 2:1 to 1:2.

[0111] Examples of preferred specific mixtures of at least one aliphatic polyisocyanate and at least one aromatic polyisocyanate are a mixture of a biuret of hexamethylene diisocyanate and a trimethylol adduct of xylylene diisocyanate, a mixture of a biuret of hexamethylene diisocyanate and a polyisocyanurate of diisocyanate, or a mixture of a biuret of hexamethylene diisocyanate and a trimethylolpropane adduct of toluene diisocyanate.

[0112] According to the present invention, in the combination of the aforementioned short-chain aliphatic polyisocyanate and long-chain aliphatic polyisocyanate, or the combination of the short-chain aliphatic polyisocyanate and long-chain aromatic polyisocyanate, or the combination of the long-chain aliphatic polyisocyanate and short-chain aromatic polyisocyanate, the polyisocyanate is a mixture in the form of a monomer, an oligomer, or a polymer.

[0113] Preferably, this results in the following combination for use in the method according to the present invention:

[0114] - Short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers);

[0115] - Short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and long-chain aliphatic polyisocyanates (monomers, oligomers, or polymers);

[0116] - Short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and short-chain aromatic polyisocyanates (monomers, oligomers, or polymers);

[0117] - Short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and long-chain aromatic polyisocyanates (monomers, oligomers, or polymers);

[0118] - Long-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers);

[0119] - Long-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and long-chain aliphatic polyisocyanates (monomers, oligomers, or polymers);

[0120] - Long-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and short-chain aromatic polyisocyanates (monomers, oligomers, or polymers);

[0121] - Long-chain aliphatic polyisocyanates (monomers) and long-chain aromatic polyisocyanates (oligomers or polymers);

[0122] Along with the previously stated definitions for short chains and long chains.

[0123] It can be observed that if at least two aliphatic polyisocyanates with different chain lengths and degrees of polymerization are selected, or a mixture of aliphatic and aromatic polyisocyanates is selected, stability and performance (fragrance release in the case of fragrance capsules) are significantly improved due to the different reaction rates of the polyisocyanate components, dissociation, and cross-linking structures.

[0124] By using the aforementioned polyisocyanate combination or polyisocyanate mixture of two different aliphatic polyisocyanates or one aliphatic polyisocyanate and one aromatic polyisocyanate, particularly stable and good, i.e., more densely branched crosslinks can be produced within the capsule shell.

[0125] Accordingly, performance (fragrance release) microcapsules can be produced from a mixture of aliphatic and aromatic polyisocyanates or from a mixture of two different aliphatic polyisocyanates by the method described herein. These microcapsules are very stable and feature excellent fragrance storage properties, which is reflected in the better performance (fragrance release) of the capsules, for example in the field of fragrance encapsulation.

[0126] Using two different polyisocyanates produces microcapsules that again exceed the stability of microcapsules made with a single polyisocyanate system, as exemplified in the following embodiment.

[0127] Microcapsules prepared from an aliphatic-aliphatic polyisocyanate mixture are as excellent as microcapsules prepared from an aliphatic-aromatic polyisocyanate mixture, as exemplified in the following embodiments. Therefore, in principle, a combination of at least two different polymerizable (preferably aliphatic and / or aromatic) polyisocyanates is preferred in the present invention.

[0128] The content of the polyisocyanate for manufacturing microcapsules according to the present invention is 0.1 to 10.0 weight%, preferably 0.5 to 3.0 weight%, based on the total weight of the internal non-aqueous phase.

[0129] The ratio of the polyisocyanate component to the internal non-aqueous phase is preferably 1:50 to 1:20, more preferably 1:40 to 1:30.

[0130] Due to the low proportion of polyisocyanate components, it is possible to produce polyurea / polyurethane microcapsules according to the present invention in which the absolute polyisocyanate ratio is only 1 / 50 of the total capsule containing at least one lipophilic active ingredient encapsulated. Accordingly, polyurea / polyurethane microcapsules having a polyisocyanate content of only 0.6% by weight based on the total weight of the capsule wall can be produced by the method according to the present invention. Preferably, the polyisocyanate content is about 1.8% by weight of the capsule wall. Despite the low polyisocyanate content, the microcapsules according to the present invention are characterized by high stability.

[0131] In step (a1) of the method for manufacturing a microcapsule according to the present invention, at least one polymerizable polyisocyanate comprising at least two isocyanate functional groups is first dissolved together with at least one active ingredient(s) to be encapsulated in a substantially inert non-aqueous solvent or a solvent mixture of inert non-aqueous solvents. “Substantially dissolved” means that at least 90 weight%, preferably at least 98 weight%, and more preferably 99.9 weight% of the aforementioned ingredients are dissolved in the solvent or solvent mixture so as to be used in the present invention. More preferably, at least one polyisocyanate and at least one active ingredient to be encapsulated are completely dissolved in the solvent or solvent mixture. If the solvent does not ensure sufficient solubility of the isocyanate, this disadvantage can be overcome by using a suitable solubility promoter.

[0132] A preferred solvent for the internal non-aqueous phase does not mix with water, does not react with the isocyanate component(s) or active ingredient(s), and has little to no odor in the amount used.

[0133] In the context of the present invention, the term "solvent" refers to any type of oil body or oil component, in particular vegetable oils, e.g., rapeseed oil, sunflower oil, soybean oil, olive oil, etc., modified vegetable oils, e.g., alkoxylated sunflower or soybean oil, synthetic (tri)glycerides, e.g., technical mixtures of mono-, di-, and triglycerides of C6 to C22 fatty acids, fatty acid alkyl esters, e.g., methyl or ethyl esters of vegetable oils, e.g., technical mixtures of mono-, di-, and triglycerides of C6 to C22 fatty acids, fatty acid alkyl esters, e.g., methyl or ethyl esters of vegetable oils (Agnique ® ME 18 RD-F, Agnique ® ME 18 SD-F, Agnique ® ME 12C-F, Agnique ®ME1270), includes fatty acid alkyl esters based on these C6 to C22 fatty acids, mineral oil, and mixtures thereof. Examples of suitable and desirable lipophilic solvents are as follows: gerbe 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, e.g., 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 Stearate, Stearyl Erucate, Isostearyl Myristate, Isostearyl Palmitate, Isostearyl Stearate, Isostearyl Isostearate, Isostearyl Oleate, Isostearyl Behenate, 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 Erusil Erucate.

[0134] Also, esters of linear C6 to C22 fatty acids with branched alcohols, particularly 2-ethylhexanol; esters of C18 to C38 alkyl hydroxycarboxylic acids with linear or branched C6 to C22 fatty acids, particularly dioctylates; esters of linear or branched fatty acids with polyhydric alcohols (e.g., propylene glycol, dimeric diol, or trimer triol) and / or gerbet alcohols; triglycerides based on C6 to C10 fatty acids; liquid mono- / di- / triglyceride mixtures of C6 to C18 fatty acids, C6 to C22 fatty alcohols and / or gerbet alcohols with aromatic carboxylic acids, particularly esters with benzoic acid; esters of C2 to C12 dicarboxylic acids with linear or branched alcohols having 1 to 22 carbon atoms or polyols having 2 to 10 carbon atoms and 2 to 6 hydroxyl groups; vegetable oils; branched primary alcohols; substituted Cyclohexane, linear or branched C6 to C22 fatty alcohol carbonates, such as dicaprylyl carbonate (Cetiol ® CC); gerbe carbonates based on fatty alcohols having 6 to 18, preferably 8 to 10 carbon atoms, benzoic acid esters having linear or branched C6 to C22 alcohols, linear or branched, symmetric or asymmetric dialkyl ethers having 6 to 22 carbon atoms per alkyl group, such as dicaprylyl ethers, ring-opening products of epoxidized fatty acid esters and polyols, silicone oils (cyclomethicone, silicon methicone grades, etc.), aliphatic or naphthenic hydrocarbons, such as squalane, squalene or dialkylcyclohexane and / or mineral oil.

[0135] Preferred solvents are also particularly esters of linear C6 to C22 fatty acids with branched alcohols, C18 to C38 alkyl hydroxycarboxylic acids with linear or branched C6 to C22 fatty alcohols, linear or branched C6 to C22 fatty alcohols, particularly esters with dioctyl maleate, linear or branched fatty acids with polyhydric alcohols, e.g., propylene glycol, dimeric diols or trimmeric triols, and / or gerbe alcohols, triglycerides based on C6 to C10 fatty acids, liquid mono- / di- / triglyceride mixtures based on C6 to C18 fatty acids, esters of C6 to C22 fatty alcohols and / or gerbe alcohols with aromatic carboxylic acids, particularly benzoic acid, C2 to C12 dicarboxylic acids with linear or branched alcohols having 1 to 22 carbon atoms or 2 to 10 carbon atoms and 2 to 6 hydroxyl Esters with polyols having a group, vegetable oils, branched primary alcohols, substituted cyclohexane, linear and branched C6- to C22-fat alcohol carbonates, e.g., dicaprylyl carbonate (Cetiol™ CC), gerbe carbonates based on fatty alcohols having 6 to 18, preferably 8 to 10, carbon atoms, esters with benzoic acid and linear or branched C6 to C22 alcohols, linear or branched, symmetric or asymmetric dialkyl ethers having 6 to 22 carbon atoms per alkyl group, e.g., dicaprylyl ether (Cetiol™ OE), ring-opening products with polyols and epoxidized fatty acid esters, silicone oils (cyclomethicone, silicon methicone type, etc.) and / or aliphatic or naphthenic hydrocarbons, e.g., squalane, squalene, or dialkylcyclohexane.

[0136] Additionally, liquid linear and / or branched and / or saturated or unsaturated hydrocarbons or any desired mixture thereof may be used as a solvent within the scope of the present invention. These may be, for example, alkanes having 4 to 22, preferably 6 to 18, carbon atoms or any mixture thereof.

[0137] Particularly advantageous inert solvents for the internal non-aqueous phase are alkyl aromatic hydrocarbons such as diisopropyl naphthalene or substituted biphenyl, chlorinated diphenyl, paraffin, chlorinated paraffin, natural vegetable oils such as cottonseed oil, peanut oil, palm oil, tricresyl phosphate, silicone oil, dialkyl phthalates, dialkyl adipates, partially hydrogenated terphenyls, alkylated biphenyls, alkylated naphthalenes, diaryl ethers, aryl alkyl ethers, and higher alkylated benzenes, benzyl benzoate, isopropyl myristate, as well as any mixture of these hydrophobic solvents and mixtures of one or several of these hydrophobic solvents with kerosene, paraffin, and / or isoparaffin. Preferably, vegetable oils such as sunflower oil, triglycerides, benzyl benzoate, or isopropyl myristate are used as solvents to provide the internal non-aqueous phase.

[0138] The aforementioned solvent is used individually or as a mixture of two or more solvents in the method according to the present invention.

[0139] In an alternative and preferred variation of the method according to the present invention, at least one polyisocyanate is directly dissolved in a solution of at least one active ingredient, preferably one or more flavorings or flavoring agents or fragrance oils, so that essentially the aforementioned solvent is not present in the core of the microcapsule according to the present invention. Not using a solvent in the microcapsule core is advantageous in that it reduces manufacturing costs and addresses environmental issues.

[0140] Fragrance compounds or flavoring agents are dissolved in solvents commonly used, particularly in the fragrance or flavoring industry. Since alcohols react with isocyanates, it is preferable that the solvent be non-alcoholic. Examples of suitable solvents include diethyl phthalate, isopropyl myristate, and Abalyn. ® (Rosin resin, commercially available from Eastman), benzyl benzoate, ethyl citrate, lymonene, or other terpenes or isoparaffins. Preferably, the solvent is highly hydrophobic. Preferably, the fragrance or flavor solution contains less than 30% solvent. More preferably, the fragrance or flavor solution contains less than 20%, and much more preferably less than 10% solvent, and all these percentages are defined as weight relative to the total weight of the fragrance or flavor solution. Most preferably, the fragrance or flavor is substantially solvent-free.

[0141] The active substance to be encapsulated or the core material for manufacturing the microcapsule according to the present invention is basically any material suitable for inclusion in the microcapsule. The material to be encapsulated is a lipophilic, water-insoluble, or water-immiscible liquid, solid, or suspension. This ensures that the active ingredient to be encapsulated is in the internal non-aqueous phase and is not mixed with the external aqueous phase when the microcapsule of the present invention is formed, otherwise an emulsion cannot be formed and deposition of the capsule wall material cannot occur on the droplet surface. Consequently, during the subsequent emulsification and crosslinking of the capsule wall component, the lipophilic active ingredient is completely surrounded inside the microcapsule as the core material. The internal non-aqueous phase thus formed is characterized by organic hydrophobic and oily properties.

[0142] In a particularly preferred variation of the present invention, at least one lipophilic or hydrophobic active substance is a lipophilic or hydrophobic fragrance or aroma substance or a lipophilic or hydrophobic fragrance oil or aroma (fragrance or aroma mixture), a freshener, a TRPV1 or TRPV3 modifier, a substance that causes a stimulating taste or a warmth or heat sensation on the skin or mucous membrane or a tingling or prickling sensation in the mouth or throat, or an active substance having a stimulating, spicy or stinging effect, a substance of the group of pesticides, biocides, insecticides, and repellents, a food additive, a cosmetic active ingredient, a pharmaceutical active ingredient, a dye, a dye precursor, a luminescent paint, a pesticide, a photobrightening agent, a solvent, a wax, a silicone oil, a lubricant, a material for printing coatings on paper, and a mixture of two or more of the aforementioned active ingredients.

[0143] In a preferred variation of the present invention, the lipophilic active ingredient is, in particular, a lipophilic fragrance compound or fragrance mixture of two or more fragrances (fragrance oils) or a flavoring agent or flavoring mixture of two or more flavoring agents (aromas) or also a biogenic principle.

[0144] It is particularly preferable that the core comprises one or more fragrance(s) or aroma(s) selected from the group consisting of: natural raw material extracts and fractions thereof or components isolated therefrom; individual fragrances of hydrocarbon groups; aliphatic alcohols; aliphatic aldehydes and acetals; aliphatic ketones and oximes; aliphatic sulfur-containing compounds; aliphatic nitriles; esters of aliphatic carboxylic acids; formates, acetates, propionates, isobutyrate, butyrate, isovalerates, pentanoates, hexanoates, crotonates, tiglinates, and 3-methyl-2-butenoates of acyclic terpene alcohols; aliphatic terpene aldehydes and ketones and their dimethyl and diethyl acetals; Formate, acetate, propionate, isobutyrate, butyrate, isovalerate, pentanoate, hexanoate, crotonate, tiglinate, and 3-methyl-2-butenoate of cyclic terpene alcohols; cyclic terpene aldehydes and ketones; cyclic alcohols; cyclic and alicyclic ethers; cyclic and macrocyclic ketones; alicyclic aldehydes; alicyclic ketones; esters of cyclic alcohols; esters of alicyclic alcohols; esters of alicyclic carboxylic acids; aromatic hydrocarbons; aromatic aliphatic alcohols; esters of aromatic aliphatic alcohols and aliphatic carboxylic acids; aromatic aliphatic ethers; aromatic and aromatic aliphatic aldehydes; aromatic and aromatic aliphatic ketones; aromatic and aromatic aliphatic carboxylic acids and their esters; nitrogen-containing aromatic compounds; phenyl ethers and phenyl esters; heterocyclic compounds; lactones; and a mixture of the above, the shell is completely or substantially impermeable to the fragrance compound(s).

[0145] Fragrance compounds and flavoring agents suitable for the production of capsules according to the present invention are preferably described, for example, in the literature ["Fragrances", in Steffen Arctander, in "Perfume and Flavor Chemicals", self-published, Montclair, NJ 1969; H. Surburg, J. Panten, in "Common Fragrance and Flavor Materials", 5th edition, Wiley-VCH, Weinheim 2006].

[0146] Preferably, the microcapsule according to the present invention comprises a core material in the form of a hydrophobic single fragrance or single aroma, wherein the core material comprises at least one single fragrance or single aroma selected from one or more of the following groups:

[0147] - Hydrocarbons, e.g., 3-carene; alpha-pinene; beta-pinene; alpha-terpinene; gamma-terpinene; p-cymene; bis-abolene; camphene; caryophyllene; cedrene; farnergen; rymonene; longipollen; myrsene; osimene; valensene; (E,Z)-1,3,5-undecatriene; styrene; diphenylmethane;

[0148] - Aliphatic alcohols, e.g., 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-methoxyoctan-2-ol; 9-decenol; 10-undecenol; 4-methyl-3-decen-5-ol;

[0149] - Aliphatic aldehydes and their acetals, e.g., 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 diethylacetal; 1,1-dimethoxy-2,2,5-trimethyl-4-hexene; citronelloloxy-acetaldehyde; 1-(1-methoxypropoxy)-(E / Z)-3-hexene;

[0150] - Aliphatic ketones and their oximes, e.g., 2-heptanone; 2-octanone; 3-octanone; 2-nonanone; 5-methyl-3-heptanone; 5-methyl-3-heptanooxime; 2,4,4,7-tetramethyl-6-octen-3-one; 6-methyl-5-hepten-2-one;

[0151] - Aliphatic sulfur-containing compounds, e.g., 3-methylthiohexanol; 3-methylthiohexyl acetate; 3-mercaptohexanol; 3-mercaptohexyl acetate; 3-mercaptohexyl butyrate; 3-acetylthiohexyl acetate; 1-menten-8-thiol;

[0152] - Aliphatic nitriles, e.g., 2-nonenenate nitrile; 2-tridecenate nitrile; 2,12-tridecenate nitrile; 3,7-dimethyl-2,6-octadienoate nitrile; 3,7-dimethyl-6-octenate nitrile;

[0153] - Aliphatic carboxylic acids and their esters, e.g., (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-methyl pentanoate; ethyl hexanoate; allyl hexanoate; Ethyl heptanoate; allyl heptanoate; ethyl octanoate; ethyl (E,Z)-2,4-decadiennoate; particularly ethyl 2-trans-4-cis-decadiennoate; methyl 2-octinate; methyl 2-noninate; allyl 2-isoamyloxyacetate; methyl 3,7-dimethyl-2,6-octadienoate; 4-methyl-2-pentylcrotonate;

[0154] - Acyclic terpene alcohols, e.g., citronellol; geraniol; nerol; linalool; lavanduol; nerolidol; farnesol; tetrahydrolinalool; tetrahydrogeraniol; 2,6-dimethyl-7-octene-2-ol; 2,6-dimethyloctan-2-ol; 2-methyl-6-methylene-7-octene-2-ol; 2,6-dimethyl-5,7-octadiene-2-ol; 2,6-dimethyl-3,5-octadiene-2-ol; 3,7-dimethyl-4,6-octadiene-3-ol; 3,7-dimethyl-1,5,7-octatriene-3-ol; 2,6-dimethyl-2,5,7-octatriene-1-ol; and its formate, acetate, propionate, isobutyrate, butyrate, isovalerate, pentanoate, hexanoate, crotonate, tiglinate or 3-methyl-2-butenoate;

[0155] - Acyclic terpene aldehydes and ketones, e.g., geranial; neral; citronellal; 7-hydroxy-3,7-dimethyloctanal; 7-methoxy-3,7-dimethyloctanal; 2,6,10-trimethyl-9-undecenal; geranylacetone; as well as dimethyl and diethylacetals of geranial, neral, and 7-hydroxy-3,7-dimethyloctanal; in particular, dimethyl and diethylacetals of geranial, neral, and 7-hydroxy-3,7-dimethyloctanal;

[0156] - Cyclic terpene alcohols, e.g., menthol; isopulegol; alpha-terpineol; terpineol-4; mentan-8-ol; mentan-1-ol; mentan-7-ol; borneol; isoborneol; linalool oxide; nopol; cedrol; ambrynol; vetiverol; guaiaol; and their formate, acetate, propionate, isobutyrate, butyrate, isovalerate, pentanoate, hexanoate, crotonate, tiglinate or 3-methyl-2-butenoate;

[0157] - Cyclic terpene aldehydes and ketones, e.g., menthone; isomentone; 8-mercaptomentan-3-one; carbone; camphor; fencone; alpha-ionone; beta-ionone; alpha-n-methylionone; beta-n-methylionone; alpha-isomethylionone; beta-isomethylionone; alpha-ionone; beta-ionone; alpha-damascenone; beta-damascenone; gamma-damascenone; delta-damascenone; gamma-damascenone; 1-(2,4,4-trimethyl-2-cyclohexene-1-yl)-2-buten-1-one; 1,3,4,6,7,8a-hexahydro-1,1,5,5-tetramethyl-2H-2,4a-methanonaphthalene-8(5H)-one; 2-methyl-4-(2,6,6-trimethyl-1-cyclohexene-1-yl)-2-butenal; nootkatone; dihydronootkatone; 4,6,8-metgastigmatrien-3-one; alpha-sinensal; beta-sinensal; acetylated cedar oil (methylcedryl ketone);

[0158] - Cyclic alcohols, e.g., 4-tert-butylcyclohexanol; 3,3,5-trimethylcyclohexanol; 3-isocampylcyclohexanol; 2,6,9-trimethyl-(Z2,Z5,E9)cyclododecatrien-1-ol; 2-isobutyl-4-methyltetrahydro-2H-pyran-4-ol; alicyclic alcohols, e.g., 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; Selected from the group of 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; and 1-(2,2,6-trimethylcyclohexyl)hexane-3-ol;

[0159] - Cyclic and alicyclic ethers, e.g., cineol; cedryl methyl ether; cyclododecyl methyl ether; 1,1-dimethoxycyclododecane; (ethoxymethoxy)cyclododecane; alpha-cedrene epoxide; 3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan; 3a-ethyl-6,6,9a-trimethyl-dodecahydronaphtho[2,1-b]furan; 1,5,9-trimethyl-13-oxabicyclo[10.1.0]trideca-4,8-diene; rose oxide; 2-(2,4-dimethyl-3-cyclohexene-1-yl)-5-methyl-5-(1-methylpropyl)-1,3-dioxane;

[0160] - Cyclic and macrocyclic ketones, e.g., 4-tert-butylcyclohexanone; 2,2,5-trimethyl-5-pentylcyclopentanone; 2-heptylcyclopentanone; 2-pentylcyclopentanone; 2-hydroxy-3-methyl-2-cyclopenten-1-one; 3-methyl-cis-2-penten-1-yl-2-cyclopenten-1-one; 3-methyl-2-pentyl-2-cyclopenten-1-one; 3-methyl-4-cyclopentadecenone; 3-methyl-5-cyclopentadecenone; 3-methylcyclopentadecanone; 4-(1-ethoxyvinyl)-3,3,5,5-tetramethylcyclohexanone; 4-tert-pentylcyclohexanone; 5-cyclohexadecen-1-one; 6,7-Dihydro-1,1,2,3,3-Pentamethyl-4(5H)-Indanone; 8-Cyclohexadecen-1-one; 7-Cyclohexadecen-1-one; (7 / 8)-Cyclohexadecen-1-one; 9-Cycloheptadecen-1-one; Cyclopentadecanone; Cyclohexadeccanone;

[0161] - Cyclomethyl aldehydes, e.g., 2,4-dimethyl-3-cyclohexenecarbaldehyde; 2-methyl-4-(2,2,6-trimethyl-cyclohexene-1-yl)-2-butenal; 4-(4-hydroxy-4-methylpentyl)-3-cyclohexenecarbaldehyde; 4-(4-methyl-3-pentene-1-yl)-3-cyclohexenecarbaldehyde;

[0162] - Cyclocycloketones, e.g., 1-(3,3-dimethylcyclohexyl)-4-penten-1-one; 2,2-dimethyl-1-(2,4-dimethyl-3-cyclohexene-1-yl)-1-1-propanone; 1-(5,5-dimethyl-2-cyclohexene-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-cyclohexene-1-yl)ketone;

[0163] - Esters of cyclic alcohols, e.g., 2-tert-butylcyclohexyl acetate; 4-tert-butylcyclohexyl acetate; 2-tert-pentylcyclohexyl acetate; 4-tert-pentylcyclohexyl acetate; 3,3,5-trimethylcyclohexyl acetate; decahydro-2-naphthyl acetate; 2-cyclopentylcyclopentyl crotonate; 3-pentyltetrahydro-2H-pyran-4-yl acetate; decahydro-2,5,5,8a-tetramethyl-2-naphthyl 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-methanooctahydro-5- or -6-indenyl acetate;

[0164] - Esters of cycloaliphatic alcohols, e.g., 1-cyclohexylethyl crotonate;

[0165] - Esters of cycloaliphatic carboxylic acids, e.g., allyl 3-cyclohexyl propionate; allyl cyclohexyloxyacetate; cis- and trans-methyl dihydrojasmonate; cis- and trans-methyl jasmonate; 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-dioxolane-2-acetate;

[0166] - Aromatic hydrocarbons, e.g., styrene and diphenylmethane;

[0167] - Aromatic aliphatic alcohols, e.g., benzyl alcohol; 1-phenylethyl alcohol; 2-phenylethyl alcohol; 3-phenylpropanol; 2-phenylpropanol; 2-phenoxyethanol; 2,2-dimethyl-3-phenylpropanol; 2,2-dimethyl-3-(3-methylphenyl)propanol; 1,1-dimethyl-2-phenyl-ethyl alcohol; 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;

[0168] - Esters of aromatic aliphatic alcohols and aliphatic carboxylic acids, e.g., benzyl acetate; benzyl propionate; benzyl isobutyrate; benzyl isovalerate; 2-phenylethyl acetate; 2-phenylethyl propionate; 2-phenylethyl isobutyrate; 2-phenylethyl isovalerate; 1-phenylethyl acetate; α-trichloromethyl benzyl acetate; α,α-dimethylphenylethyl acetate; α,α-dimethylphenylethyl butyrate; cinnamyl acetate; 2-phenoxyethyl isobutyrate; 4-methoxybenzyl acetate;

[0169] - Aromatic aliphatic ethers, e.g., 2-phenylethyl methyl ether; 2-phenylethyl isoamyl ether; 2-phenylethyl 1-ethoxyethyl ether; phenylacetaldehyde dimethylacetal; phenylacetaldehyde diethylacetal; hydra tropaaldehyde dimethylacetal; phenylacetaldehyde glycerolacetal; 2,4,6-trimethyl-4-phenyl-1,3-dioxane; 4,4a,5,9b-tetrahydroindeno[1,2-d]-m-dioxin; 4,4a,5,9b-tetrahydro-2,4-dimethylindeno[1,2-d]-m-dioxin;

[0170] - Aromatic and aromatic aliphatic aldehydes, e.g., benzaldehyde; phenylacetaldehyde; 3-phenylpropanal; hydratropaldehyde; 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; α-butylcinnamaldehyde; α-amylcinnamaldehyde; α-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;

[0171] - Aromatic and aromatic aliphatic ketones, e.g., acetophenone; 4-methylacetophenone; 4-methoxyacetophenone; 4-tert-butyl-2,6-dimethylacetophenone; 4-phenyl-2-butanone; 4-(4-hydroxyphenyl)-2-butanone; 1-(2-naphthalenyl)ethanolone; benzophenone; 1,1,2,3,3,6-hexamethyl-5-indanyl methyl ketone; 6-tert-butyl-1,1-dimethyl-4-indanyl methyl ketone; 1-[2,3-dihydro-1,1,2,6-tetramethyl-3-(1-methylethyl)-1H-5-indenyl]ethanolone; 5',6',7',8'-tetrahydro-3',5',5',6',8',8'-hexamethyl-2-acetonaftone;

[0172] - Aromatic and aromatic aliphatic carboxylic acids and their esters, e.g., benzoic acid; phenylacetic acid; methyl benzoate; ethyl benzoate; hexyl benzoate; benzyl benzoate; methyl phenyl acetate; ethyl phenyl acetate; geranyl phenyl acetate; phenyl ethyl phenyl acetate; methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenyl ethyl cinnamate; cinnamyl cinnamate; allyl phenoxyacetate; methyl salicylate; isoamyl salicylate; hexyl salicylate; cyclohexyl salicylate; cis-3-hexenyl salicylate; benzyl salicylate; phenyl ethyl salicylate; methyl 2,4-dihydroxy-3,6-dimethyl benzoate; ethyl 3-phenyl glycidate; ethyl 3-methyl-3-phenyl glycidate;

[0173] - Nitrogen-containing aromatic compounds, e.g., 2,4,6-trinitro-1,3-dimethyl-5-tert-butylbenzene; 3,5-dinitro-2,6-dimethyl-4-tert-butylacetophenone; cinnamate nitrile; 5-phenyl-3-methyl-2-pentenoic acid nitrile; 5-phenyl-3-methylpentanoic acid nitrile; methyl anthranilate; methyl N-methyl anthranilate; Schiff base of methyl anthranilate having 7-hydroxy-3,7-dimethyloctanal, 2-methyl-3-(4-tert-butylphenyl)propanal or 2,4-dimethyl-3-cyclohexenecarbaldehyde; 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;

[0174] - Phenols, phenyl ethers, and phenyl esters, e.g., tragol; 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-cresylphenyl acetate; groups of heterocyclic compounds, e.g., 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;

[0175] - Lactones, e.g., 1,4-octanolide; 3-methyl-1,4-octanolide; 1,4-nonolide; 1,4-decanolide; 8-decene-1,4-olide; 1,4-undecanolide; 1,4-dodecanolide; 1,5-decanolide; 1,5-dodecanolide; 1,15-pentadecanolide; cis- and trans-11-pentadecene-1,15-olide; cis- and trans-12-pentadecene-1,15-olide; 1,16-hexadecanolide; 9-hexadecene-1,16-olide; 10-oxa-1,16-hexadecanolide; 11-oxa-1,16-hexadecanolide; 12-oxa-1,16-hexadecanolide; ethylene-1,12-dodecanedioate; ethylene-1,13-tridecanedioate; coumarin; 2,3-dihydrocoumarin; octahydrocoumarin;

[0176] In addition, stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers, or epimers of the aforementioned substances; and mixtures of the aforementioned substances.

[0177] In a further variation of the method according to the present invention, the flavoring material may also be encapsulated as a core material in the form of a single flavoring agent, wherein the core material comprises at least one single flavoring material or a mixture thereof as an active material.

[0178] Typical examples of flavor substances or flavor agents that can be encapsulated in the sense of the present invention are selected from the group consisting of the following: acetophenone; allyl capronate; alpha ionone; beta ionone; anisaldehyde; anisyl acetate; anisyl formate; benzaldehyde; benzothiazole; benzyl acetate; benzyl alcohol; benzyl benzoate; beta ionone; butyl butyrate; butyl capronate; butylidene phthalide; carbon; camphene; caryophyllene; cineole; cinnamyl acetate; citral; citronellol; citronellal; citronellol acetate; cyclohexyl acetate; cymene; damaskone; decalactone; dihydrocoumarin; dimethyl anthranilate; dimethyl anthranilate; dodecalactone; ethoxyethyl acetate; ethyl butyric acid; ethyl butyrate; ethyl capronate; ethyl capronate; Ethyl crotonate; ethyl furaneol; ethyl guaiacol; ethyl isobutyrate; ethyl isovalerate; ethyl lactate; ethyl methylbutyrate; ethyl propionate; eucalyptol; eugenol; ethyl heptylate; 4-(p-hydroxyphenyl)-2-butanone; gamma-decalactone; geraniol; geranyl acetate; geranyl acetate; grapefruit aldehyde; methyl dihydrozasmonate (e.g., Hedion ®); Heliotropin; 2-Heptanone; 3-Heptanone; 4-Heptanone; Trans-2-Heptenal; Cis-4-Heptenal; Trans-2-Hexenal; Cis-3-Hexenol; Trans-2-Hexenic Acid; Trans-3-Hexenic Acid; Cis-2-Hexenyl Acetate; Cis-3-Hexenyl Acetate; Cis-3-Hexenyl Capronate; Trans-2-Hexenyl Capronate; Cis-3-Hexenyl Formate; Cis-2-Hexyl Acetate; Cis-3-Hexyl Acetate; Trans-2-Hexyl Acetate; Cis-3-Hexyl Formate; Para-Hydroxybenzylacetone; Isoamyl Alcohol; Isoamyl Isovalerate; Isobutyl Butyrate; Isobutyraldehyde; Isoeugenol Methyl Ether; Isopropyl Methyl Thiazole; Lauric acid; revelinic acid; Linalool; Linalool oxide; Linalyl acetate; Menthol; Mentofuran; Methyl anthranilate; Methyl butanol; Methyl butyric acid; 2-Methyl butyl acetate; Methyl capronate; Methyl cinnamate; 5-Methyl furfural; 3,2,2-Methylcyclopentenolone; 6,5,2-Methylheptenone; Methyl dihydrojasmonate; Methyl jasmonate; 2-Methyl methyl butyrate; 2-Methyl-2-pentenoic acid; Methyl thiobutyrate; 3,1-Methylthiohexanol; 3-Methylthiohexyl acetate; Nerol; Neryl acetate; Trans,trans-2,4-nonadienal; 2,4-nonadienol; 2,6-nonadienol; 2,4-nonadienol; Nootkatone; Delta-octalactone; Gamma-octalactone; 2-octanol; 3-octanol; 1,3-octenol; 1-octyl acetate; 3-octyl acetate; Palmitic acid; Paraldehyde; Phelandrene; Pentanedione; Phenylethyl acetate; Phenylethyl alcohol; Phenylethyl alcohol; Phenylethyl isovalerate; Piperonal; Propionaldehyde; Propyl butyrate; Pulegone; Pulegol; Sinensal; Sulfurol; Terpinene; Terpineol; Terpinolene; 8,3-Thiomentanone; 4,4,2-Thiomethylpentanone; Thymol; Delta-undecalactone; Gamma-undecalactone; Valencen; Valeric acid; Vanillin; Acetoin; Ethyl vanillin; Ethyl vanillin isobutyrate (3-ethoxy-4-isobutyryloxybenzaldehyde);2,5-dimethyl-4-hydroxy-3(2H)-furanone and its derivatives (preferably homofuraneol (2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone), homofuronol (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-lactone (preferably gamma-undecalactone, gamma-nonalactone, gamma-decalactone); delta-lactone (preferably 4-methyldelta-decalactone, masoylactone, delta-decalactone, tuberolactone); methyl sorbate; divanillin; 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)furanone; 2-hydroxy-3-methyl-2-cyclopenthenone; 3-hydroxy-4,5-dimethyl-2(5H)-furanone; isoamyl acetate ester; ethyl butyrate ester; n-butyl butyrate ester; isoamyl butyrate ester; 3-ethyl butyrate ester; n-ethyl hexanoate ester; n-allyl hexanoate ester; n-n-butyl hexanoate ester; n-ethyl octanoate ester; ethyl 3-methyl-3-phenyl glycidate; ethyl 2-trans-4-cis-decadienoate; 4-(p-hydroxyphenyl)-2-butanone; 1,1-dimethoxy-2,2,5-trimethyl-4-hexane; 2,6-dimethyl-5-heptene-1-al; Phenylacetaldehyde; 2-methyl-3-(methylthio)furan; 2-methyl-3-furanthiol; bis(2-methyl-3-furyl)disulfide; furfuryl mercaptan; methional; 2-acetyl-2-thiazolin; 3-mercapto-2-pentanone; 2,5-dimethyl-3-furanthiol; 2,4,5-trimethylthiazole; 2-acetylthiazole; 2,4-dimethyl-5-ethylthiazole; 2-acetyl-1-pariroline; 2-methyl-3-ethylpyrazine; 2-ethyl-3,5-dimethylpyrazine; 2-ethyl-3,6-dimethylpyrazine; 2,3-diethyl-5-methylpyrazine; 3-isopropyl-2-methoxypyrazine; 3-isobutyl-2-methoxypyrazine; 2-Acetylpyrazine; 2-Pentylpyridine; (E,E)-2,4-Decadienal; (E,E)-2,4-Nonadienal; (E)-2-Octenal; (E)-2-Nonenal;2-undecenal; 12-methyltridecanal; 1-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; cinnam alcohol; methyl salicylate; isopulegol, as well as stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers, or epimers of these substances not expressly mentioned herein; and mixtures of the aforementioned substances.;

[0179] Among the aforementioned individual fragrance compounds that can be encapsulated in the sense of the present invention, fragrance compounds having an aldehyde, carboxylic acid, or ester functional group are preferred.

[0180] Aldehyde fragrances, including not only the corresponding acetal but also esters and lactones, can be divided into the following groups:

[0181] (i) Aliphatic aldehydes and their acetals;

[0182] (ii) cycloaliphatic aldehydes;

[0183] (iii) Aromatic or aromatic aliphatic aldehydes;

[0184] (vi) aliphatic, aromatic or aromatic aliphatic esters; and

[0185] (v) lactone;

[0186] and a mixture of these.

[0187] The aforementioned fragrances having aldehyde, carboxylic acid, or ester functional groups and mixtures thereof are selected from one or more of the following groups:

[0188] - Aliphatic aldehydes and their acetals, e.g., hexanal; heptanal; octanal; nonanal; decanal; undecanal; dodecanal; tridecanal; 2-methyloctanal; 2-methylnonanal; (f)-2-hexenal; (Z)-4-heptenal; 2,6-dimethyl-5-heptenal; 10-undecenal; (f)-4-decenal; 2-dodecenal; 2,6,10-trimethyl-5,9-undecadienal; heptanal-diethylacetal; 1,1-dimethoxy-2,2,5-trimethyl-4-hexene; citronelloloxy-acetaldehyde;

[0189] - Cyclomethyl aldehydes, e.g., 2,4-dimethyl-3-cyclohexenecarbaldehyde; 2-methyl-4-(2,2,6-trimethyl-cyclohexene-1-yl)-2-butenal; 4-(4-hydroxy-4-methylpentyl)-3-cyclohexenecarbaldehyde; 4-(4-methyl-3-pentene-1-yl)-3-cyclohexenecarbaldehyde;

[0190] - Aromatic and aromatic aliphatic aldehydes, e.g., benzaldehyde; phenylacetaldehyde; 3-phenylpropanal; hydratropaldehyde; 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; α-butylcinnamaldehyde; α-amylcinnamaldehyde; α-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;

[0191] - Aliphatic carboxylic acid esters, e.g., (E)- and (Z)-3-hexenyl formate; ethyl acetoacetate; isoamyl acetate; hexyl acetate; 3,5,5-trimethylhexyl acetate; 3-methyl-2-butenyl acetate; (f)-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-methyl pentanoate; ethyl hexanoate; allyl hexanoate; ethyl heptanoate; Allyl heptanoate; ethyl octanoate; ethyl (E,Z)-2,4-decadiennoate; methyl 2-octinate; methyl 2-noninate; allyl 2-isoamyloxyacetate; methyl 3,7-dimethyl-2,6-octadienoate;

[0192] - Esters of cyclic alcohols, e.g., 2-tert-butylcyclohexyl acetate; 4-tert-butylcyclohexyl acetate; 2-tert-pentylcyclohexyl acetate; 4-tert-pentylcyclohexyl acetate; decahydro-2-naphthyl acetate; 3-pentyltetrahydro-2H-pyran-4-yl acetate; decahydro-2,5,5,8a-tetramethyl-2-naphthyl 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-methanooctahydro-5- or -6-indenyl acetate;

[0193] - Esters of aromatic aliphatic alcohols and aliphatic carboxylic acids, e.g., benzyl acetate; benzyl propionate; benzyl isobutyrate; benzyl isovalerate; 2-phenylethyl acetate; 2-phenylethyl propionate; 2-phenylethyl isobutyrate; 2-phenylethyl isovalerate; 1-phenylethyl acetate; α-trichloromethyl benzyl acetate; α,α-dimethylphenylethyl acetate; α,α-dimethylphenylethyl butyrate; cinnamyl acetate; 2-phenoxyethyl isobutyrate; 4-methoxybenzyl acetate

[0194] - Esters of cycloaliphatic carboxylic acids, e.g., allyl 3-cyclohexyl propionate; allyl cyclohexyloxyacetate; methyl dihydrojasmonate; methyl jasmonate; 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-dioxolane-2-acetate;

[0195] - Aromatic and aromatic aliphatic carboxylic acid esters, e.g., methyl benzoate; ethyl benzoate; hexyl benzoate; benzyl benzoate; methyl phenyl acetate; ethyl phenyl acetate; geranyl phenyl acetate; phenyl ethyl phenyl acetate; methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenyl ethyl cinnamate; cinnamyl cinnamate; allyl phenoxy acetate; methyl salicylate; isoamyl salicylate; hexyl salicylate; cyclohexyl salicylate; cis-3-hexenyl salicylate; benzyl salicylate; phenyl ethyl salicylate; methyl 2,4-dihydroxy-3,6-dimethyl benzoate; ethyl 3-phenyl glycidate; ethyl 3-methyl-3-phenyl glycidate.

[0196] Listed below are aldehydes, acetals, esters, and lactones having particularly preferred commercial names as representatives of groups (i) to (v) for the purposes of the method according to the present invention:

[0197] Aldehyde: 2-Methylpentanal; Aldehyde C12 MNA HM; Aldehyde C4; Aldehyde C5; Aldehyde C6; Aldehyde C7; Aldehyde C8; Aldehyde C9; Aldehyde C10; Aldehyde C11 ISO; Aldehyde C11 MOA Pure; Aldehyde C11 Undecaneal; Aldehyde C11 Undaleyldenic; Aldehyde C12; Aldehyde C12 MNA; Aldehyde C13; Aldehyde Madarin; Amyl Cinnamate Aldehyde Alpha; Anisaladehyde-O; Anisyl Aldehyde; Benzaldehyde NAT.; Bergamale; Boronal; Burgenolal; Camponelate Aldehyde; Citral; Citronellal HM; Citronellol Oxyacetaldehyde; Citraylal; Citroylal E HM; Cortexaldehyde; Cortexaldehyde 50 PCT Remosa; Crotonate aldehyde; Cuminal aldehyde; Cyclamene aldehyde; Decadienal trans, trans-2,4, Decanal cis-4; Decanal trans-2; Decanal trans-2 NAT; Decanal trans-4; Decanal-9,1; Dodecamienal 2,6; Dodecanal trans-2; Dupical; Epoxydecenal-4,5-2 10% TRI; Ethyl hexanal; FARENAL ® ; Fluophidral; Geraldehyde; Helianal; Heliophane; Heliotropin; Heptadienal trans, trans,2-4; Heptenal cis-4; Heptenal trans-2; Hexenal trans-2; Hexyl cinnamate aldehyde alpha; Hydratropic aldehyde; Hydroxy cytronellal; Intrelebenaldehyde SPEC.; Isononyl aldehyde; Isovaleric aldehyde; Lemon aldehyde H&R JS I; Lilianal; Linolal; Lyral; Malyantal; Mandninal; Mandrine aldehyde 10% IN TEC BHT; Mepranaal; MELONAL ®; Methodicitronellal; Methyl butyraldehyde; Methyl cinnamaldehyde alpha; Methyl phenylpentenal-4,2,2; Methylthiopropanal-3; Methyl tridecanaal-12 10% VT; Methyl-3-butene-2-yl; Methyl-5-phenyl-2-hexene-2-AL; Milgunal 50 DPG; NEOcyclocitral; Nonadienal; Trans, cis-2,6; Nonenal cis-6; Nonenal trans-2; ONCIDAL ® 3 / 060251; Pentenal trans-2; Perilla aldehyde; Phenylacetaldehyde; Phenylbutenal trans-2,2; Phenylpropylaldehyde; Pinoacetaldehyde; Propranesal; Propionalaldehyde 2-(P-Tolyl); Propionic acid aldehyde; PS-Iraldelin X NEU; Safranal; Salicylic acid aldehyde FG; Silvial; Tetrahydrocitral; Tigliate aldehyde-2,2; Tolylaldehyde para FG; Tridecenal trans-2; Trifernal; Undecadienal-2,4; Undecenal trans-2; Bom'ialdehyde; Bertocitral; Bertomugal; Bertiprenal; Vetrallal ROH; Zimtaldehyde NAT. HM; Acetal: Florophal; Heptanal diethyl acetal; Nonandienal diethyl acetal; Okumal; Phenylacetate ALD. Glycerin acetal; Phenylacetaldehydrodimethylacetal; Esters: Jasmal; Jesemal; Charimal; TIRAMISONE ® .

[0198] In an alternative embodiment, the polyurea / polyurethane microcapsule according to the present invention uses a flavor mixture or fragrance oil or flavor mixture or flavor agent as the encapsulated active ingredient or as the core material. These are compositions containing at least one fragrance compound or one flavor agent and which can be used in the preparation of such fragrance oil or aroma. Such compositions, particularly flavor mixtures or fragrance oils, preferably comprise 2, 3, 4, 5, 6, 7, 8, 9, 10 or more fragrance compounds. The flavor mixture or fragrance oil preferably comprises extracts of natural raw materials; essential oils, concretes, absolutes, resins, resinoids, balsams, tinctures, e.g., ambergris tincture; amyris oil; angelica seed oil; angelica root oil; anise oil; ammoise oil; valerian oil; basil oil; tree moss absolute; bay oil; wormwood oil; benzoin resin; bergamot oil; beeswax absolute; birch tar oil; Almond oil; Savory oil; Buco leaf oil; Cabreuba oil; Juniper oil; Calmus oil; Camphor oil; Cananga oil; Cardamom oil; Cascarilla oil; Cassia oil; Cassia absolute; Castorium absolute; Cedar leaf oil; Cedar oil; Cistus oil; Citronella oil; Citron oil; Copaiba balsam; Copaiba balsam oil; Coriander oil; Coastus root oil; Cumin oil; Cypress oil; Davana oil; Dill herb oil; Dill seed oil; Eau de brouts absolute; Oak moss absolute; Elemi oil; Tarragon oil; Eucalyptus citriodora oil; Eucalyptus oil; Fennel oil; Spruce needle oil; Fir oil; Galbanum oil; Galbanum resin; Geranium oil; Grapefruit oil; Limonium oil; Gurjune balsam; Geojeon Balsam Oil, Helichrysum Absolute; Helichrysum Oil; Ginger Oil; Iris Root Absolute; Iris Root Oil; Jasmine Absolute; Sweet Flag Oil; Chamomile Oil Blue; Chamomile Oil Roman;Carrot seed oil; Cascarilla oil; Pine needle oil; Curly mint oil; Caraway oil; Labanum oil; Labanum absolute; Labanum resin; Lavandin absolute; Lavandin oil; Lavender absolute; Lavender oil; Lemongrass oil; Rovigi oil; Distilled lime oil; Pressurized lime oil; Linal oil; Lithea cubeba oil; Laurel oil; Laurel leaf oil; Masis oil; Marjoram oil; Mandarin oil; Masoi bark oil; Mimosa absolute; Musk grain oil; Musk tincture; Muscat sage oil; Nutmeg oil; Myrrh absolute; Myrrh oil; Myrtle oil; Clove leaf oil; Clove flower oil; Neroli oil; Olivanum absolute; Olivanum oil; Opopanax oil; Orange blossom absolute; Orange oil; Origanum oil; Palmarosa oil; Patchouli oil; Perilla oil; Peruvian balsam oil; Parsley leaf oil; Parsley seed oil; Petitgrain oil; Peppermint oil; Black pepper oil; Allspice oil; Pine oil; Poly 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; Styrox oil; Tazetes oil; Fir oil; Tea tree oil; Turpentine oil; Thyme oil; Tolu balsam; Tonca oil; Tuberose absolute; Vanilla extract; Violet leaf absolute; Verbena oil; Vetiver oil; Pinus densiflora berry oil; Wine yeast oil; Wormwood oil; Wintergreen oil; Ylang-ylang oil; Hyssop oil; Musk oil; Cinnamon leaf oil; Cinnamon bark oil; It is selected from the group consisting of its fractions or components isolated therefrom.

[0199] Exemplary refreshing agents used as lipophilic active ingredients in the preparation of microcapsules according to the present invention include menthol and menthol derivatives (e.g., L-menthol, D-menthol, racemic menthol, isomenthol, neoisomenthol, neomenthol), menthyl ethers (e.g., (1-mentoxy)-2-propanediol, (1-mentoxy)-2-methyl-1,2-propanediol, 1-mentyl methyl ether), menthyl esters (e.g., menthyl formate, menthyl acetate, menthyl isobutyrate, menthyl lactate, L-mentyl L-lactate, L-mentyl D-lactate, menthyl (2-methoxy) acetate, menthyl (2-methoxyethoxy) acetate, menthyl pyroglutamate), and menthyl carbonates (e.g., menthyl propylene glycol carbonate, menthyl ethylene glycol). Carbonates, menthyl glycerol carbonates, or mixtures thereof), semiesters of menthol with dicarboxylic acids or their derivatives (e.g., monomenthyl succinate, monomenthyl glutarate, monomenthyl malonate, O-menthyl succinate-N,N-(dimethyl)amide, O-menthyl succinamide), menthane carboxamides (e.g., menthane carboxylic acid-N-ethylamide [WS3], N-alpha-(methane carbonyl) glycine ethyl ester [WS5], menthane carboxylic acid-N-(4-cyanophenyl)amide, menthane carboxylic acid-N-(alkoxyalkyl)amide), menthone and menthone derivatives (e.g., L-menthone glycerol ketal), 2,3-dimethyl-2-(2-propyl)-butanoic acid derivatives (e.g., It comprises one or more of 2,3-dimethyl-2-(2-propyl)-butanoic acid-N-methylamide [WS23]), isopulegol or its esters (1-(-)-isoopulegol, 1-(-)-isoopulegol acetate), mentan derivatives (e.g., p-mentan-3,8-diol), cubebol, or synthetic or natural mixtures containing cubebol, pyrrolidone derivatives of cycloalkyldione derivatives (e.g., 3-methyl)-2-(1-pyrrolidinyl)-2-cyclopenten-1-one), or tetrahydropyrimidine-2-one (e.g., icillin or related compounds described in WO 2004 / 026840).Other refreshing agents are menthol (L-menthol, D-menthol, racemic menthol, isomenthol, neoisomenthol, neomenthol), L-mentyl methyl ether, menthyl formate, menthyl acetate), menthone, isofullegol, L-(-)-isofullegol acetate), and cubebol, which have a refreshing effect. Suitable refreshing agents are well known in the art and are described, for example, in US 2017 / 216802 (A1), US 2010 / 273887 (A1), EP 2 033 688 (A2), and EP 1 958 627 (A2).

[0200] In an alternative variation, TRPV1 or TRPV3 modulators are used as the encapsulated active substance or as the core material of the polyurea / polyurethane microcapsule according to the present invention. TRPV1 and TRPV3 modulators are known in the prior art and relate to TRP (transient receptor potential) channels of the vanilloid (TRPV) subfamily. TRPV1 modulators convey the spicy taste and hot sensation associated with capsaicin and piperine. TRPV3 proteins belong to a family of non-selective cation channels that function in various processes, including temperature sensation and vascular regulation. TRPV3 channels are directly activated by several natural compounds, such as carvacrol, thymol, and eugenol. Some other monoterpenoids that induce warmth or are skin sensitizers can also open the channels. Monoterpenoids also induce agonist-specific desensitization of TRPV3 channels in a calcium-independent manner.

[0201] In a further variation, the polyurea / polyurethane microcapsule according to the present invention uses an active substance selected from the group consisting of a substance that causes a stimulating taste or a warm or hot sensation on the skin or mucous membrane or a tingling sensation in the mouth or throat, or an active substance that has a stimulating, spicy, or stinging effect, as the encapsulated active substance or as the core material.

[0202] The heat-inducing or stimulating active ingredient is preferably selected from the group consisting of: paprika powder, chili pepper powder, paprika extract, pepper extract, chili pepper extract, ginger root extract, paradise grain (Aframomum melegueta) extract, Paracress (Zambu oleoresin; Spilanthes acmella, or Spilanthes oleracea) extract, Japanese pepper (Xanthophyllum piperitum) extract, Caemperia galanga extract, Alpinia galanga extract, Wafer pepper (Polygunium hydropiper) extract, capsaicinoids, in particular capsaicin, dihydrocapsaicin, or nonivamide; gingerol, in particular gingerol-[6], gingerol-[8], or gingerol-

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

[10] ; Gingerdione, particularly gingerdione-[6], gingerdione-[8] or gingerdione-

[10] ; paradol, particularly paradol-[6], paradol-[8] or paradol-

[10] ; dehydrogingerdione, particularly dehydrogingerdione-[6], dehydrogingerdione-[8] or dehydrogingerdione-

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

[0203] The active substance perceived as irritating or spicy is preferably selected from the group consisting of aromatic isothiocyanates, in particular phenyl ethyl isothiocyanate, allyl isothiocyanate, cyclopropyl isothiocyanate, butyl isothiocyanate, 3-methylthiopropyl isothiocyanate, 4-hydroxybenzyl isothiocyanate, 4-methoxybenzyl isothiocyanate, and mixtures thereof.

[0204] The tingling agents are preferably selected 2E,4E-decadienoic acid-N-isobutylamide (trans-pellitorin), in particular those described in WO 2004 / 043906; 2E,4Z-decadienoic acid-N-isobutylamide (cis-pellitorin), in particular those modified 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-methylbutylamide); 2E,4Z-Decadienate-N-(2-methylbutyl)amide; 2E,4E-Decadienate-N-piperid (Acylamide); 2E,4E-Decadienate-N-piperid (Samentin); 2E-Decenate-N-isobutylamide; 3E-Decenate-N-isobutylamide; 3E-N-noneneate-isobutylamide; 2E,6Z,8E-Decatrienoate-N-isobutylamide (Spilanthol); 2E,6Z,8E-Decatrienoate-N-([2S]-2-methylbutyl)amide (Homospilanthol); 2E,6Z,8E-Decatrienoate-N-([2R]-2-methylbutyl)amide; 2E-Decenate-4-inosate-N-isobutylamide; 2Z-Decene-4-Inosan-N-Isobutylamide; 2E,6Z,8E,10E-Dodecatetraenoic acid-N-(2-methylpropyl)amide (alpha- 2E,4E,8E,10E,12E-Tetradecapentaenoic acid-N-(2-hydroxy-2-methylpropyl)amide (gamma-hydroxyisoacidol); 2E,4E,8Z,10E,12E-Tetradecapentaenoic acid-N-(2-methyl-2-propenyl)amide (gamma-dehydrosanshol); 2E,4E,8Z,10E,12E-Tetradecapentaenoic acid-N-(2-methylpropyl)amide (gamma-sanshol);Selected from the group consisting of 2E,4E,8Z,11Z-tetradecaterenoic acid-N-(2-hydroxy-2-methylpropyl)amide (Bungeanul); 2E,4E,8Z,11E-tetradecaterenoic acid-N-(2-hydroxy-2-methylpropyl)amide (isobungeanul); 2E,4E,8Z-tetradecaterenoic acid-N-(2-hydroxy-2-methylpropyl)amide (dihydrobungeanul) and 2E,4E-tetradecaterenoic acid-N-(2-hydroxy-2-methylpropyl)amide (tetrahydrobungeanul) and mixtures thereof.;

[0205] The active substance having a tingling effect is preferably selected from the group consisting of catechins, in particular epicatechin, gallocatechin, epigallocatechin and their respective gallic acid esters, in particular epigallocatechin gallate or epicatechin gallate, their oligomers (procyanidin, proanthocyanidin, prodelphinidin, procyanitrin, thearubigenin, theogalin) and their C- and O-glycosides; dihydroflavonoids such as dihydromyricetin, taxifolin, and their C- and O-glycosides; flavonols such as myricetin, quercetin and their C- and O-glycosides such as quercetin, rutin; gallic acid esters of carbohydrates such as tannin, pentagalloylglucose or their reaction products such as elligatannin; aluminum salts, for example, alum; and mixtures thereof. An exemplary pyrogen used as a lipophilic active ingredient in the manufacture of microcapsules according to the present invention is included.

[0206] In a further variation of the method according to the present invention, the biogenic principle may also be encapsulated as a core material, wherein the core material comprises at least one biogenic principle or a mixture thereof.

[0207] The biogenic principle is active ingredients with biological activity, such as tocopherol, tocopherol acetate, tocopherol palmitate, ascorbic acid, carnotine, carnosine, caffeine, (deoxy)ribonucleic acid and its fragmentation products, β-glucan, retinol, basilol, allantoin, phytantriol, panthenol, AHA acids, amino acids, ceramides, pseudoceramides, essential oils, plant extracts, and vitamin complexes.

[0208] In a further variation of the method according to the present invention, a material for printing coating on paper is also used as an active ingredient or a core material that is encapsulated as described in US 2800457A, the full text of which is incorporated herein by reference.

[0209] The content of the lipophilic active ingredient or mixture of lipophilic active ingredients for manufacturing microcapsules according to the present invention is 90.0 to 99.9 weight%, preferably 97.0 to 99.5 weight%, based on the total weight of the internal non-aqueous phase.

[0210] The ratio of one or more active ingredient components to the internal non-aqueous phase is preferably 50:1 to 20:1, more preferably 40:1 to 30:1.

[0211] Therefore, it is possible to achieve a high load of the microcapsules of the present invention having an active ingredient by using the method according to the present invention.

[0212] Additionally, the first polymerization and / or crosslinking step (a) of the method according to the present invention comprises providing an external aqueous phase comprising at least one protective colloid and optionally an emulsifier (a2).

[0213] To this end, the protective colloid and optionally the emulsifier are dissolved in an external aqueous phase, preferably an aqueous solvent. A suitable solvent is water or a mixture of at least one water-miscible organic solvent. Suitable organic solvents are, for example, glycerol, 1,2-propanediol, 1,3-propanediol, ethanediol, diethylene glycol, triethylene glycol, and other analogs. However, preferably, the solvent is water.

[0214] A protective colloid is a polymer system that prevents the agglomeration, coagulation, or flocculation of emulsified, suspended, or dispersed components in a suspension or dispersion. During solvation, the protective colloid combines with a large amount of water and, depending on the concentration, generates high viscosity in the aqueous solution. During the production of oil-in-water emulsions, the protective colloid attaches to primary particles containing hydrophobic portions, converting the polar, or hydrophilic, molecular portions into the aqueous phase. Through this attachment to the interface, it lowers interfacial tension and prevents the agglomeration of the primary particles. It also stabilizes the emulsion and promotes the formation of relatively small droplets, thereby forming corresponding microcapsules.

[0215] In the method according to the present invention, the protective colloid also exhibits emulsifying properties in addition to the aforementioned properties. If the emulsifying properties of the protective colloid, such as carboxymethyl cellulose, acid-modified starch, polyvinyl alcohol, ammonium derivatives of polyvinyl alcohol, polystyrene sulfonate, polyvinylpyrrolidone, and polyvinyl acrylate, are sufficient, the use of an emulsifier may advantageously be omitted in the method according to the present invention.

[0216] The protective colloid used in the method according to the present invention is selected from the group consisting of the following:

[0217] - Diols, in particular ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, butanediol isomer, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-dodecanediol, and

[0218] - 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 hydroxyethylcellulose, in particular quaternized hydroxyethylcellulose, or carboxymethylcellulose,

[0219] - Polyvinylpyrrolidone, vinyl maleate copolymer, sodium lignosulfonate, maleic anhydride / styrene copolymer, ethylene / maleic anhydride copolymer, ethylene oxide, copolymer of acid ester of propylene oxide and polyethoxylated sorbitol, sodium dodecyl sulfate,

[0220] - Animal and plant polymers, especially gum arabic (Senegal type and Seyal type), proteins, gelatin, olibanum resin, shellac, lignin, chitosan, saponin,

[0221] In addition, a mixture of the aforementioned compounds.

[0222] Preferably, the outer aqueous phase comprises at least one protective colloid selected from polyvinylpyrrolidone, polyvinyl alcohol, and mixtures thereof. Polyvinylpyrrolidone is particularly preferred. Commercial standard polyvinylpyrrolidone has a molecular weight in the range of about 2,500 to 750,000 g / mol. Polyvinyl alcohol or its ammonium derivative, 1,3,5-trihydroxybenzene, or starch, particularly modified starch, or animal or plant polymers as protective colloids are particularly preferred for the manufacture of microcapsules according to the present invention.

[0223] Starch, particularly modified starch or animal or plant polymers, is a naturally occurring biodegradable material. Together with the polyisocyanates described herein, the present method can thus provide a bio-based and biodegradable capsule shell. Thus, in the method according to the present invention, starch and animal or plant polymers act as so-called bio-crosslinking agents.

[0224] The starch used in the method according to the present invention is selected from the group consisting of corn starch, potato starch, rye starch, wheat starch, barley starch, oat starch, rice starch, oat starch, tapioca starch, and mixtures thereof.

[0225] Chemically modified starch is preferably acid-modified starch, alkali-modified starch, oxidized starch, acetylated starch, succinate starch, or oxenyl succinate starch.

[0226] According to the present invention, a combination of two or more different protective colloids can also be used to produce microcapsules according to the present invention.

[0227] It has been proven to be particularly advantageous in the method according to the present invention when a combination of one of the aforementioned protective colloids and starch is used as an additional protective colloid in the external aqueous phase. This combination stabilizes the emulsion due to a large number of functional hydroxyl groups, while promoting the reaction between the protective colloid and the polyisocyanate(s), so that the reaction equilibrium in the reaction between the protective colloid and the polyisocyanate(s) shifts toward the product, i.e., polyurethane. A large number of functional hydroxyl groups in the starch also enable the formation of spatially particularly prominent crosslinks.

[0228] Depending on the number of functional groups and / or the size of the protective colloid, the aforementioned protective colloid has different reaction rates with the isocyanate group of at least one polyisocyanate. For example, glycerol reacts more quickly with the isocyanate group than starch due to its size. Therefore, the crosslinking of the isocyanate group of the polyisocyanate with the protective colloid can be controlled by the selection of the protective colloid.

[0229] It has been proven that a combination of glycerol or glycerol with starch or modified starch and quaternized hydroxyethyl cellulose or gum arabic Seyal is a particularly advantageous combination; with such a combination, one utilizes the aforementioned characteristics of two protective colloids on the one hand: the high reaction rate of glycerol and on the other hand, the number of polymerizable functional groups of starch.

[0230] The protective colloid used in the method according to the present invention acts as a protective colloid to prevent aggregation of emulsified, suspended, or dispersed components, stabilizes the emulsion subsequently formed, and stabilizes the formation of small droplets and ultimately the dispersion of formed microcapsules.

[0231] On the other hand, the protective colloid crosslinks with at least one polyisocyanate(s) during polymerization due to polymerizable properties, such as functional groups, particularly OH groups. Due to the crosslinking with at least one polyisocyanate, a polymer layer is already formed during the emulsification step (a3), which contributes to the structure of the capsule wall and becomes a component thereof.

[0232] Surprisingly, while emulsifying or suspending an inner non-aqueous phase in an outer aqueous phase in the presence of a protective colloid, preferably a polyol, polymerization and / or crosslinking is formed near the core by interfacial polymerization at the interface of the emulsified or suspended hydrophobic droplets of the encapsulated active material, which forms the core and outer phases of the microcapsule according to the present invention. Polymerization and / or crosslinking is based on a mediant addition reaction of a polyisocyanate and a protective colloid, preferably a polyol, to form a capsule shell or capsule wall of polyurethane according to the following formula.

[0233] n O=C=NR 1 -N=C=O + n HO-R 2 -OH-→ (-R 2 -O-CO-NH-R 1 -NH-CO-O-) n

[0234] This manifests as gas generation and carbon dioxide emission.

[0235] By forming a polymer layer during the emulsification step, the encapsulated active ingredient(s), particularly active ingredients having aldehyde, carboxylic acid, or ester functional groups, are protected, so that if necessary, deprotonation, oxidation, or saponification can be prevented or at least minimized, especially in subsequent method steps, and consequently, the loss of lipophilic active ingredient(s) can be reduced or eliminated; such degradation products generally contribute to the instability of the emulsion.

[0236] According to the present invention, the ratio of the amounts of protective colloid or colloids used in the aqueous phase is preferably in the range of 1:50 to 1:10, more preferably in the range of 1:40 to 1:30.

[0237] The ratio of the protective colloid in the outer aqueous phase to the polyisocyanate in the inner non-aqueous phase is in the range of 1:5 to 1:2, preferably in the range of 1:2 to 1:1.

[0238] Accordingly, the amount of protective colloid used or the amount of protective colloid combination used is in the range of 1 to 8 weight%, preferably 2 to 4 weight%, and more preferably 3 to 4 weight% based on the total weight of the external aqueous phase.

[0239] At least one protective colloid may or may not be a component of the capsule shell. In particular, as described above, a protective colloid having higher reactivity will react more quickly and easily with the isocyanate groups of the polyisocyanate component and thus will form polyurethane crosslinking units that are part of the capsule shell or capsule wall in an amount ranging from 0.1 to a maximum of 15 weight%, but preferably 1 to 5 weight%, and more preferably 1.5 to 3 weight% based on the weight of the capsule.

[0240] To facilitate the formation of an emulsion from an internal non-aqueous phase and an external aqueous phase, to stabilize the formed emulsion, and to prevent separation of the internal non-aqueous (oily / organic / hydrophobic) phase and the external aqueous (hydrophilic) phase, an emulsifier or an emulsifying aid is optionally added to the external aqueous phase in the method according to the present invention. The addition of the emulsifier is optionally performed when the protective colloid has no or low emulsifying properties, i.e., when they are insufficient. When an emulsifying protective colloid is used, the use of the emulsifier may be advantageously omitted in the method according to the present invention.

[0241] In the method according to the present invention, an O / W emulsifier is preferably used as an emulsifier, which enables a uniform distribution of oil droplets in the inner non-aqueous phase within the outer aqueous phase and stabilizes the emulsion. The same applies when a solid, insoluble active material in the outer aqueous phase is mixed to stabilize the dispersion thus obtained.

[0242] Suitable emulsifiers include, for example, non-ionic surfactants from at least one of the following groups:

[0243] - Addition product of 2 to 30 moles of ethylene oxide and / or 0 to 5 moles of propylene oxide to a linear fatty alcohol having 8 to 22 carbon atoms, a fatty acid having 12 to 22 carbon atoms, an alkylphenyl having 8 to 15 carbon atoms in an alkyl group, as well as an alkylamine having 8 to 22 carbon atoms in an alkyl group;

[0244] - Alkyl and / or alkenyl oligoglycosides having 8 to 22 carbon atoms within an alk(en)yl radical and their ethoxylated analogs;

[0245] - Add product of 1 to 15 moles of ethylene oxide to castor oil and / or hydrogenated castor oil;

[0246] - Add product of 15 to 60 moles of ethylene oxide to castor oil and / or hydrogenated castor oil;

[0247] - A partial ester of glycerol and / or sorbitan with an unsaturated, linear or saturated, branched fatty acid having 12 to 22 carbon atoms and / or a partial ester of a hydroxycarboxylic acid having 3 to 18 carbon atoms and its adduct with 1 to 30 moles of ethylene oxide;

[0248] - Polyglycerol (average degree of self-condensation of 2 to 8), polyethylene glycol (molecular weight 400 to 5000), trimethylolpropane, pentaerythritol, sugar alcohol (e.g., sorbitol), alkyl glucosides (e.g., methyl glucoside, butyl glucoside, lauryl glucoside), and polyglucosides (e.g., cellulose), and partial esters with saturated and / or unsaturated, linear or branched fatty acids having 12 to 22 carbon atoms and / or hydroxycarboxylic acids having 3 to 18 carbon atoms, as well as their adducts having 1 to 30 moles of ethylene oxide, preferably Cremophor ® ;

[0249] - Mixed esters of pentaerythritol, fatty acids, citric acid and fatty alcohols and / or mixed esters of fatty acids having 6 to 22 carbon atoms, methylglucose and polyols, preferably glycerol or polyglycerol;

[0250] - Mono-, di-, and trialkyl phosphates, as well as mono-, di- and / or tri-PEG-alkyl phosphates and their salts;

[0251] - Wool wax alcohol;

[0252] - Polysiloxane-polyalkyl-polyether copolymer or a corresponding derivative;

[0253] Block copolymers, e.g., polyethylene glycol 30 dipolyhydroxystearate; polymer emulsifiers, e.g., Goodrich’s Pemulen type (TR-1, TR-2) or Cognis’ Cosmedia ® SP;

[0254] - Polyalkylene glycol and glycerin carbonate.

[0255] Typical anionic emulsifiers that can be used in the method of the present invention for manufacturing isocyanate-based microcapsules are aliphatic fatty acids having 12 to 22 carbon atoms, such as palmitic acid, stearic acid, or behenic acid, as well as dicarboxylic acids having 12 to 22 carbon atoms, such as azelaic acid or sebacic acid.

[0256] In addition, zwitterionic surfactants can be used as emulsifiers in the method of the present invention for the manufacture of isocyanate-based microcapsules. The term zwitterionic surfactant is used to describe surface-active compounds having at least one quaternary ammonium group, at least one carboxylate group, and one sulfonate group within the molecule. Particularly suitable zwitterionic surfactants are so-called betaines, such as N-alkyl-N,N-dimethylammonium glycinate, e.g., cocoalkyl dimethylammonium glycinate, N-acylaminopropyl-N,N-dimethylammonium glycinate, e.g., cocoacylaminopropyl dimethylammonium glycinate, and 2-alkyl-3-carboxymethyl-3-hydroxyethylimidazoline (each having 8 to 18 carbon atoms within the alkyl or acyl group), as well as cocoacylaminoethylhydroxyethylcarboxymethylglycinate. A fatty acid amide derivative known as CTFA cocamidopropyl betaine is particularly preferred.

[0257] Amphoteric surfactants are also suitable emulsifiers. Amphoteric surfactants are surface-active compounds capable of forming internal salts, comprising at least one free amino group and at least one -COOH or -SO3H group in addition to a C8 / 18 alkyl or acyl group within the molecule. Examples of suitable amphoteric surfactants are alkylglycine, N-alkylpropionic acid, N-alkylaminobutyric acid, N-alkyliminodipropionic acid, N-hydroxyethyl-N-alkylamidopropylglycine, N-alkyltaurine, N-alkylarcosine, 2-alkylaminopropionic acid, and alkylaminoacetic acid (each having about 8 to 18 carbon atoms in the alkyl group). Particularly preferred amphoteric surfactants are N-cocoalkylaminopropionate, cocoacylaminoethylaminopropionate, and C12 / 18-acylarcosine.

[0258] Finally, cationic surfactants can also be considered as emulsifiers, such as ester querate types, preferably methyl-quaternized difatty acid triethanolamine ester salts, quaternized hydroxyethylcellulose, propylene glycol, epichlorohydrin, distearyldimethylammonium chloride (DSDMAC), benzalkonium chloride, benzetonium chloride, cetylalkonium chloride, cetylpyridinium chloride, cetyltrimethylammonium bromide (cetrimonium bromide), and quaternized modified chitosan, and diqualinium chloride is particularly preferred.

[0259] Each emulsifier may be added to the outer aqueous phase in an amount of about 0.5 to about 10 weight percent, preferably about 1 to about 5 weight percent, based on the total weight of the outer aqueous phase.

[0260] An aqueous protective colloid-emulsifier solution is preferably prepared by adding the protective colloid and optionally the emulsifier to the outer aqueous phase sequentially or vice versa, or by adding the protective colloid and optionally the emulsifier to the outer aqueous phase simultaneously while stirring.

[0261] For the manufacture of polyurea / polyurethane microcapsules according to the present invention, it may be advantageous to optionally contain a dissolved or dispersed stabilizer to prevent the external aqueous phase from separating from the internal non-aqueous (oily) phase and the external aqueous phase.

[0262] A preferred stabilizer for the preparation of isocyanate-based microcapsules according to the present invention is an acrylic copolymer having mainly sulfonate groups. In addition, copolymers of acrylamide and acrylic acid, copolymers of alkyl acrylate and N-vinylpyrrolidone, such as LUVISKOL ®K15, K30, or K90 (BASF); sodium polycarboxylates, sodium polystyrene sulfonates, vinyl and methyl vinyl ether-maleic anhydride copolymers, as well as ethylene, isobutylene, or styrene-maleic anhydride copolymers, commercially available, e.g., under the name VIVAPUR ® Commercially available microcrystalline cellulose, diutan gum, xanthan gum, or carboxymethyl cellulose is suitable.

[0263] The amount of stabilizer used may be in the range of 0.01 to 10 weight% in each case with respect to the external aqueous phase, particularly in the range of 0.1 to 3 weight%.

[0264] The oil-in-water emulsion is prepared by mixing an internal non-aqueous phase and an external aqueous phase. The weight ratio of the internal non-aqueous phase to the external aqueous phase is preferably 2:1 to 1:10, more preferably 1:2 to 1:4.

[0265] For liquid active ingredients, emulsion formation, or for solid active ingredients, dispersion formation—that is, the emulsification or dispersion of an internal non-aqueous or oily phase from an external aqueous or hydrophilic phase—occurs under high turbulence or strong shear. The diameter of the obtained microcapsules can be determined by the turbulence or shear intensity. Droplet size can be verified by light scattering measurements or microscopic examination. The production of microcapsules can be continuous or discontinuous. As the viscosity of the aqueous phase increases or the viscosity of the oil phase decreases, the size of the capsules produced generally decreases.

[0266] The method according to the present invention for producing polyurea / polyurethane microcapsules may be carried out, for example, through a forced metering pump according to "in-line" technology, or in a conventional dispersion device or a stirring emulsification device.

[0267] The emulsification or dispersion of an internal non-aqueous phase within an external aqueous phase for the formation of microcapsules according to the present invention was performed by an emulsification turbine (IKA Eurostar 20 high-speed stirrer). The emulsification method in step (a3) ​​of the method according to the present invention is advantageously performed for a time of 30 seconds to 20 minutes, preferably 1 to 4 minutes, at a stirring speed of 1000 rpm to 5000 rpm, preferably 3000 rpm to 4000 rpm.

[0268] After the completion of the emulsification or dispersion step (a3), there exists an oil-in-water emulsion or dispersion in which an inner oil phase having an encapsulated active ingredient is finely dispersed or emulsified in an outer aqueous phase in the form of droplets.

[0269] In a subsequent step (a4) of the method according to the present invention, a first polymerization and / or crosslinking of the material of the capsule shell or capsule wall is also carried out under stirring. The first crosslinking is preferably carried out by adding at least one first amino acid or at least one amino acid hydrochloride in the presence of a catalyst in the form of an aqueous solution. The addition of the amino acid or amino acid hydrochloride and the catalyst is preferably carried out at a temperature of 20 to 30°C.

[0270] At least one first amino acid is selected from the group consisting of arginine, histidine, lysine, tryptophan, ornithine, and mixtures thereof.

[0271] It is often advantageous to use amino acids as hydrochlorides. Hydrochlorides of the aforementioned amino acids are more easily soluble in water and thus are more easily soluble in the external aqueous phase. In addition, the use of amino acids as hydrochlorides shifts the pH of the reaction mixture to acidity, and in addition to improved solubility, the reactivity between at least one polyisocyanate and the first amino acid increases, so polymerization and / or crosslinking between these two components can be expected.

[0272] 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.

[0273] The amino acids arginine, lysine, and ornithine, or their corresponding amino acid hydrochlorides, are compounds having two amino groups in their side chains. The amino acids histidine and tryptophan, or their corresponding hydrochlorides, each have one amino group and one NH functional group in their side chains. Thus, the aforementioned amino acids or their amino acid hydrochlorides exhibit multifunctionality for polymerization with at least one polyisocyanate.

[0274] Due to the crosslinking between at least one polyisocyanate and at least one amino acid or amino acid hydrochloride functional group, a first crosslinking unit or a first crosslinking matrix is ​​formed, which becomes part of the capsule shell or capsule wall.

[0275] Among the aforementioned amino acids, the basic reactive amino acid arginine or its hydrochloride analog is particularly preferred as a crosslinking agent due to its water solubility as an amino acid and hydrochloride, high reactivity, and pH.

[0276] Using amino acids or amino acid hydrochlorides as crosslinking agents is particularly advantageous from an environmental perspective in terms of biodegradability and biocompatibility.

[0277] The amino acid or amino acid hydrochloride, i.e., the first crosslinking agent, is added to the emulsion as itself, for example, as a solid or preferably in the form of an aqueous solution. The amino acid or amino acid hydrochloride is present in the aqueous solution at a concentration of 0.5 to 2 mol / l, preferably 1 mol / l.

[0278] The amount of at least one amino acid or amino acid hydrochloride is adjusted so that 1 to 3 moles of amino groups, preferably 1 to 3 moles of amino groups, are added per mole of isocyanate group.

[0279] In the method according to the present invention, the first crosslinking is performed for a period of about 10 to 20 minutes, preferably for a period of about 12 to 18 minutes, most preferably for a period of about 15 minutes.

[0280] The amount of at least one amino acid or amino acid hydrochloride is typically adjusted so that 1 to 3 moles of amino groups, preferably 1 to 2 moles of amino groups, are added per mole of isocyanate group.

[0281] No specific action is required to induce polymerization between at least one polyisocyanate or multiple polyisocyanates and a first amino acid or amino acid hydrochloride. The reaction begins immediately after adding the amino acid or amino acid hydrochloride to an oil-in-water emulsion or dispersion to form a first crosslinking unit or a first crosslinking matrix. A catalyst is not required because the reaction between at least one polyisocyanate or multiple polyisocyanates and an amino acid or amino acid hydrochloride is sufficiently fast.

[0282] In the method according to the present invention, the formation of the first crosslinking unit is based on a polyisocyanate or a polyisocyanate with an amino acid or an amino acid hydrochloride. The first crosslinking unit forming the capsule shell or capsule wall is based on a polyurea structure. The polyurea linkage or polyurea structure is formed by the addition of at least one amino acid or at least one amino acid hydrochloride's amino group(s) (-NH2) to the isocyanate group of at least one polyisocyanate:

[0283] n O=C=NR 1 -N=C=O + n H2N-R2 -→ (-O-NH-R 1 -NH-CO-NH-R 2 -) n

[0284] In the method according to the present invention, a first crosslinking matrix or a first crosslinking unit, in particular a polyurea crosslinking unit, for the composition of a capsule shell or capsule wall is formed by interfacial polymerization at the interface of an emulsified or suspended oil droplet containing a lipophilic active substance to be encapsulated.

[0285] By forming a first cross-linking matrix or a first cross-linking unit, the oil droplet emulsified or dispersed together with the core material, i.e., the encapsulated active ingredient, is surrounded by the cross-linking matrix or cross-linking unit outside the interface, thereby creating a capsule wall that makes it more difficult for the encapsulated active ingredient to diffuse.

[0286] When a catalyst is added to an emulsion or dispersion, the reaction between the polyisocyanate and the amino acid or amino acid hydrochloride is promoted, and the reaction is promoted for the formation of a polyurea crosslinking matrix.

[0287] The catalyst added in the method according to the present invention is preferably diazabicyclo[2.2.2]octane (DABCO), also known as triethylenediamine (TEDA), a cyclic tertiary amine. DABCO is generally used as a catalyst for the production of polyurethane plastics. Tertiary amines having free electron pairs promote the reaction between at least one polymerizable polyisocyanate in the internal non-aqueous phase and the amino group of an amino acid or amino acid hydrochloride.

[0288] In addition to DABCO, for example, bismuth or tin-based catalysts are also used for the catalytic action of the first crosslink, such as bismuth(II) salt or bismuth(III) salt-based catalysts, as described in the literature in which the full text is incorporated herein by reference [KC Frisch & LP Rumao, Catalysis in Isocyanate Reactions, Polymer Reviews, 1970, 5:1, pages 103 - 149, DOI: 10.1080 / 15583727008085365].

[0289] Diazabicyclo[2.2.2]octane (DABCO) is particularly desirable as a catalyst.

[0290] According to the present invention, a combination of DABCO and one of the aforementioned catalysts is preferred. Such a mixture doubles the reactivity as described in the literature [KC Frisch & LP Rumao, Catalysis in Isocyanate Reactions, Polymer Reviews, 1970, 5:1, pages 103 - 149, DOI: 10.1080 / 15583727008085365], the disclosure thereof is incorporated herein in its entirety.

[0291] In the method according to the present invention, DABCO and the aforementioned catalyst preferably catalyze a polyurethane reaction between at least one polymerizable polyisocyanate having two or more isocyanate groups and a diol or polyol.

[0292] The amount of catalyst added to the emulsion or dispersion is in the range of 0.01 to 1 weight percent, preferably 0.05 to 0.2 weight percent, based on the total weight of the emulsion or dispersion. For slow polymerization reactions, the amount of catalyst required can be appropriately adjusted.

[0293] The ratio of the catalyst to at least one polyisocyanate or isothiocyanate in the internal non-aqueous phase of the emulsion or dispersion is preferably in the range of 1:20 to 1:50.

[0294] It was found that it is advantageous to first disperse or dissolve the catalyst in water and then add it to the emulsion or dispersion while stirring.

[0295] The amino acid or amino acid hydrochloride and the catalyst are added at a stirring speed preferably from 500 rpm to 2000 rpm, particularly preferably from 1000 rpm to 1500 rpm, and at a temperature of 20°C to 30°C, preferably from 22°C to 26°C.

[0296] In the method according to the present invention, the first polymerization and / or crosslinking is performed for a period of about 10 to 20 minutes, preferably for a period of about 12 to 18 minutes, most preferably for a period of about 15 minutes.

[0297] Surprisingly, adding a catalyst after the emulsification or suspension step significantly increases capsule stability. Capsules produced in this way exhibit significantly high stability even after 10 days at 50°C, and the amount of free fragrance oil is significantly reduced compared to microcapsules produced without the addition of a catalyst and control capsules.

[0298] In particular, stable capsules can be produced using the catalyst diazabicyclo[2.2.2]octane (DABCO).

[0299] In the method according to the present invention, the first polymerization and / or crosslinking step (a) is further followed by a second polymerization and / or crosslinking step (b) by adding at least one hydroxyl group donor to the oil-in-water emulsion or dispersion obtained in the method step (a4) to further build a capsule shell or capsule wall.

[0300] At least one hydroxyl group donor is preferably a polyol having two or more hydroxyl functional groups having excellent to very excellent water solubility at temperatures above 40°C.

[0301] The hydroxyl group donor is selected from the group consisting of glycerol, propylene glycol, 1,3,5-trihydroxybenzene, starch, modified starch, cellulose derivatives such as hydroxyethyl cellulose, particularly quaternized hydroxyethyl cellulose, or carboxymethyl cellulose, gum arabic (Senegal type and Seyal type), and mixtures thereof. Glycerol and starch are preferred; glycerol is most preferred.

[0302] The starch used in the method according to the present invention is selected from the group consisting of corn starch, potato starch, rye starch, wheat starch, barley starch, oat starch, rice starch, oat starch, tapioca starch, and mixtures thereof.

[0303] Modified starch is preferably chemically modified oil, namely acid-modified starch, alkali-modified starch, oxidized starch, acetylated starch, succinate starch, or oxenyl succinate starch.

[0304] According to the present invention, a combination of two different types of the aforementioned hydroxyl group donors can also be used to produce microcapsules according to the present invention.

[0305] Depending on their size, the aforementioned hydroxyl group donors have different reaction rates with the isocyanate groups of at least one polyisocyanate. For example, glycerol reacts more quickly with the isocyanate groups than starch because of its size.

[0306] Therefore, it has been proven that particularly advantageous combinations are combinations of starch or modified starch with glycerol, or glycerol with quaternized hydroxyethyl cellulose or gum arabic type Seyal; such combinations utilize, on the one hand, the high reaction rate of the two hydroxyl donors: glycerol, and on the other hand, the aforementioned characteristics of the number of polymerizable functional groups of starch.

[0307] Through the reaction of at least one polyisocyanate and / or isothiocyanate with the hydroxyl group of a hydroxyl group donor, an additional, i.e., second crosslinking matrix or second crosslinking unit is formed for the composition or formation of a capsule shell or capsule wall, and the structure can be derived from the polyisocyanate and protective colloid similarly to the first crosslinking unit as described above.

[0308] The heavy addition reaction between at least one polyisocyanate and a hydroxyl group donor involves adding the hydroxyl group (-OH) of the hydroxyl group donor to the carbon atom of the carbon-nitrogen bond of the polyisocyanate group (-N=C=O) to form a so-called urethane bridge (-NH-CO-C-).

[0309] By forming these additional polyurethane crosslinking units, the first polyurea crosslinking unit formed in the first polymerization and / or crosslinking step (a4) is further crosslinked and densified.

[0310] In particular, to obtain an efficient, dense, and stable crosslink, the second polymerization and / or crosslinking step (b) with a hydroxyl group donor is carried out at temperatures of 40°C and 60°C, and preferably at temperatures of 45°C to 55°C, and more preferably at temperatures of 45°C to 50°C.

[0311] In addition, the additional crosslinking step is preferably performed by adding a hydroxyl group donor at a stirring speed of 900 rpm to 1700 rpm, preferably 1000 rpm to 1300 rpm.

[0312] In this context, it has been found that the addition of an aqueous form of a hydroxyl group donor produces a particularly stable crosslink and, therefore, a particularly stable capsule shell or capsule wall. The concentration of the hydroxyl group donor in the aqueous solution is preferably 10% to 70%, and more preferably 40% to 60%.

[0313] In the method according to the present invention, after the second crosslinking step (b), an additional step, namely a third polymerization and / or crosslinking step (c), follows. In this third crosslinking step, at least one additional step, namely a second amino acid, is added to the oil-in-water emulsion obtained in the crosslinking step (b).

[0314] 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.

[0315] The aforementioned amino acid is a compound having at least one amino group in its side chain and thus exhibits functionality for polymerization and / or crosslinking with at least one polyisocyanate.

[0316] Among the aforementioned amino acids, basic reactive amino acids such as histidine, lysine, or arginine, or their hydrochloride analogs, are particularly desirable because both the amino acid and the hydrochloride are highly reactive and have high pH values.

[0317] Arginine is particularly preferred as a crosslinking agent in the method according to the present invention due to its solubility in water.

[0318] Using amino acids or amino acid hydrochlorides as crosslinking agents is particularly advantageous from an environmental perspective in terms of biodegradability and biocompatibility.

[0319] The second amino acid is added to the emulsion or dispersion, for example, as a solid or, preferably, in the form of an aqueous solution. The second is present in the aqueous solution at a concentration of 0.5 to 2 mol / l, preferably 1 mol / l.

[0320] The amount of at least one second amino acid or amino acid hydrochloride is typically adjusted so that 1 to 3 moles of amino groups, preferably 1 to 2 moles of amino groups, are added per mole of isocyanate group.

[0321] The addition of the second amino acid or amino acid hydrochloride is preferably carried out at a stirring speed of 500 rpm to 2000 rpm, more preferably 1000 rpm to 1500 rpm, and at a temperature of 60 to 80°C, preferably 60°C.

[0322] By the addition of a second amino acid, a third crosslinking matrix or a third crosslinking unit is formed in the method according to the present invention for the construction of a capsule shell or capsule wall. These third crosslinking units form a capsule shell or capsule wall based on a polyurea structure based on a reaction of a polyisocyanate or an individual polymer or oligomer of polyisocyanates and an amino acid. The formation of a polyurea linkage or a polyurea structure is achieved by the addition of at least one amino group(s) (-NH2) of an amino acid to at least one isocyanate isocyanate:

[0323] n O=C=NR 1 -N=C=O + n H2N-R 2 - +→ (-O-NH-R 1 -NH-CO-NH-R 2 -) n

[0324] By forming these additional polyurea crosslinking units, the polyurea crosslinking units and polyurethane crosslinking units formed in the first and second polymerization and / or crosslinking steps (a4) and (b) are further crosslinked and densified.

[0325] In the method according to the present invention, the third crosslinking is performed for a period of about 10 to 20 minutes, preferably for a period of about 12 to 18 minutes, most preferably for a period of about 15 minutes.

[0326] The third crosslinking step is performed at a temperature of 60 to 80°C, preferably 60°C.

[0327] A combination of a first polymerization or crosslinking step between a polyisocyanate and a first amino acid, a second polymerization or crosslinking step between a polyisocyanate and a hydroxyl group donor, and a third polymerization or crosslinking step between a polyisocyanate and a second amino acid results in the formation of a polyurea and polyurethane crosslinking unit or crosslinking matrix forming a capsule shell or capsule wall. The first, second, and third polyurea and polyurethane crosslinking units are further crosslinked spatially to each other and to each other by sequential crosslinking steps in the method of the present invention.

[0328] The greater the number of crosslinking functional groups, the greater the spatial crosslinking, and the more stable the capsule shell or wall of the resulting microcapsule becomes. In addition to the number of functional groups, the chain length of individual building blocks significantly affects the mechanical properties of the capsule, namely its stability. For example, a large number of hydroxyl groups in starch enables the formation of particularly prominent spatial crosslinks. Long-chain capsule shell or wall building blocks, such as polyisocyanates, form more stable capsule shells or walls.

[0329] During the aforementioned crosslinking step, the stirring force is reduced so that the crosslinking unit forming the capsule shell is not immediately destroyed, and preferably, the stirring speed is reduced to about 800 to 1200 rpm.

[0330] After the third polymerization or crosslinking step and complete crosslinking and the formation of the capsule shell or capsule wall, the capsule produced according to the method of the present invention exists as an unpurified microcapsule in the form of an aqueous dispersion or slurry.

[0331] After crosslinking, the microcapsules in the slurry still have flexible shells that are not particularly stable and therefore break easily. To address this, the shells of the microcapsules are cured. Curing is preferably performed by gradually raising the temperature of the microcapsule dispersion to at least 60°C, preferably in the range of 60 to 65°C, up to the maximum boiling point of the microcapsule dispersion. Curing is generally performed for a period of at least 60 minutes, preferably 2 to 4 hours.

[0332] In addition, it is advantageous to add a substance to the external aqueous phase for curing. For this purpose, natural plant tannins of the tannin type are used, which are proanthocyanidins found, from a chemical perspective, in dicotyledonous shrubs, bushes, and leaves, particularly in tropical and subtropical regions. The molecular weight of the terpene is generally in the range of 500 to 3000 kDa. A preferred example of a suitable tannin is corigalin. For curing, an aqueous formulation of tannin is added to an aqueous dispersion containing unpurified microcapsules. Typically, the tannin is added in an amount of about 0.1 to about 2 weight percent, preferably about 0.5 to about 1.5 weight percent, based on the microcapsules.

[0333] After the curing step (d) of the method according to the present invention, in an additional method step (e), at least one release agent is added to the microcapsule dispersion or microcapsule slurry, which is absorbed into the microcapsule shell or microcapsule wall or preferably incorporated into the microcapsule shell or microcapsule wall.

[0334] Release agents are generally liquid or paste-like materials that prevent adhesion between two materials. In the case of the present invention, these are materials incorporated into the microcapsule shell or microcapsule wall to form ionic or even covalent bonds with the existing cross-linked structure of the capsule material through functional groups, such as OH groups or COOH groups.

[0335] At least one release agent used in the method according to the present invention is selected from the group consisting of fatty acids, fatty alcohols, fatty acid esters, and animal and vegetable waxes.

[0336] Fatty acids are mostly aliphatic monocarboxylic acids with unbranched carbon chains. Fatty acids differ in the number of carbon atoms (chain length) and—in the case of unsaturated fatty acids—the number and location of double bonds. Depending on chain length, 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).

[0337] Fatty alcohols are aliphatic, long-chain, monovalent, and mostly primary alcohols. Hydrocarbon residues are often unbranched in natural fatty alcohols, and synthetic fatty alcohols are also often branched. The carbon chains have 6 to 30 carbon atoms and may be monounsaturated or polyunsaturated. Fatty alcohols are found in natural waxes linked by carboxylic acid esters, for example, in wool wax or spermaceti, and are often called wax alcohols.

[0338] Wax is an organic compound that melts at temperatures above approximately 40°C to form a low-viscosity liquid. Waxes can vary significantly in their chemical composition and origin. The main components of these mixtures are esters of fatty acids and long-chain aliphatic primary alcohols, known as fatty alcohols. These esters differ in structure from fats and fatty oils, which are fatty acids and triglycerides. Additionally, these waxes contain free, long-chain, aliphatic carboxylic acids, ketones, alcohols, and hydrocarbons. Wax can be of animal or plant origin.

[0339] In the method according to the present invention, at least one release agent is preferably selected from the group consisting of:

[0340] - Long-chain, aliphatic, linear or branched, saturated or unsaturated carboxylic acids (fatty acids) having 12 to 30 carbon atoms, in particular lauric acid (12:0), tridecanoic acid (13:0), myristic acid (14:0), pentadecanic acid (15:0), palmitic acid (16:0), margaric acid (17:0), stearic acid (18:0), nonadecanic acid (19:0), arachidic acid (20:0), heneicosanic acid (21:0), behenic acid (22:0), lignoceric acid (24:0), cerotic acid (26:0), montanic acid (28:0) and melisic acid (30:0); Myristoleic acid (14:1), palmitoleic acid (16:1), margaroleic acid (17:1), petroselinic acid (18:1), oleic acid (18:1), ellaidic acid (18:1), vacsenic acid (18:1), gadolic acid (20:1), gondoleic acid (20:1), cetolic acid (22:1), erucic acid (22:1), nervonic acid (24:1), linoleic acid (18:2), alpha-linolenic acid (18:3), gamma-linolenic acid (18:3), calendulic acid (18:3), punic acid (18:3), alpha-eloeostearic acid (18:3), beta-eloeostearic acid (18:3), stearidonic acid (18:4), arachidonic acid (20:4), eicosapentaenoic acid (20:5), Docosa-tetraenoic acid (ADA) (22:4), docosa-pentaenoic acid (DPA-3) (22:5), docosa-hexaenoic acid (22:6) and tetracosa-hexaenoic acid (24:6); phytic acid;

[0341] - Long-chain, aliphatic, linear or branched, saturated or unsaturated primary alcohols (fatty alcohols) having 12 to 30 carbon atoms, in particular lauryl alcohol (12:0), myristyl alcohol (14:0), palmityl alcohol (16:0), margaryl alcohol (17:0), stearyl alcohol (18:0), arachidyl alcohol (20:0), behenyl alcohol (22:0), lignoceryl alcohol (24:0), ceryl alcohol (26:0), montanyl alcohol (28:0) and melisyl alcohol (30:0); palmitoleyl alcohol (16:1), oleyl alcohol (18:1), elaedyl alcohol (18:1), linoleyl alcohol (18:2), gamma-linolenyl alcohol (18:3);

[0342] - Esters of a long-chain, aliphatic saturated carboxylic acid having 12 to 30 carbon atoms and a long-chain, aliphatic primary alcohol having 12 to 30 carbon atoms, in particular lauryl palmitate, myrisyl palmitate, cetylarakinate and stearyl behenate; and

[0343] - Animal and vegetable waxes, especially wool wax, china wax, beeswax, sunflower seed wax, rice bran wax, carnauba wax, pinova wax, rapeseed wax, soybean wax, candelilla wax, jojoba oil, cork wax, guarama wax, cotton wax, flax wax, peat wax, rose wax, jasmine wax, pita wax from washigood, as well as myrtle wax ( Myrica Seripera ), wax, pig wax, berry wax, and a mixture of two or more of the above release agents.

[0344] Among the carboxylic acids listed above, saturated fatty acids are preferred. In the method according to the present invention, the most preferred method is to use the animal and vegetable waxes specified above due to their low melting point, which facilitates incorporation into the microcapsule shell or microcapsule wall.

[0345] At least one release agent has two functions: incorporating the release agent into the microcapsule shell or microcapsule wall and forming ionic or covalent bonds with the release agent and the crosslinking unit or crosslinking matrix provides additional stabilization of the microcapsule shell on the one hand. On the other hand, incorporating the release agent into the microcapsule shell or microcapsule wall creates a predetermined limit for the degradability of the microcapsule shell—that is, a point on the microcapsule wall designed for the degradation of the microcapsule material to occur first. This promotes the degradation of the microcapsule shell or microcapsule wall. The use of a release agent that stabilizes the microcapsule shell or microcapsule wall also makes it possible to reduce other capsule wall materials that are less biodegradable or not biodegradable at all.

[0346] A release agent is added to the microcapsule dispersion or microcapsule slurry in an amount of 1 to 10 weight percent based on the capsule shell. Preferably, the release agent is added in an amount of 2 to 5 weight percent based on the capsule shell.

[0347] At least one release agent is added to the microcapsule dispersion or microcapsule slurry at a temperature of at least 60°C to the maximum boiling point of the microcapsule dispersion, preferably 80°C. At this temperature, the release agent exists in a liquid or molten form, so it can be easily dissolved and incorporated into the existing cross-linked structure of the microcapsule shell.

[0348] After adding at least one release agent, a step of post-curing the polyurea / polyurethane microcapsules obtained in step (f) is performed, preferably at a temperature of at least 60°C to 100°C and for a period of 60 to 240 minutes.

[0349] After curing, the microcapsules produced according to the method of the present invention exist as an aqueous dispersion, also known as a microcapsule dispersion or microcapsule slurry. In this form, the microcapsules are essentially already marketable.

[0350] It has been proven advantageous for the viscosity of the suspension to be 12 to 1500 mPas in order to achieve high storage stability by preventing separation or creaming of the suspension. To obtain the desired viscosity of the suspension, it is desirable to use a thickening agent.

[0351] It is preferable to use xanthan gum, diutan gum; carboxymethyl cellulose (CMC), microcrystalline cellulose (MCC), or guar gum as a thickening agent.

[0352] To improve shelf life, one or more preservatives are optionally added to the microcapsule slurry or the microcapsule slurry is dried.

[0353] Preferably, 1,2-hexanediol, 1,2-octanediol, or parmetol is used as a preservative.

[0354] Alternatively, microcapsules are separated and dried for preservation purposes.

[0355] In principle, methods such as freeze-drying can be used for this purpose, but spray drying in a fluidized bed, for example, is preferred. It has been proven advantageous to add additional polysaccharides, preferably dextrin, in particular maltodextrin, to the dispersion at a temperature of about 20 to about 50°C, preferably about 40°C, which supports the drying process and protects the capsule during this process. The amount of polysaccharides used in the dispersion may be about 50 to about 150% by weight, preferably about 80 to about 120% by weight, based on the mass of the capsule.

[0356] Spray drying itself can be performed continuously or in batches in a conventional spray system at 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 and preferably about 72 to 78°C.

[0357] An important criterion for the utility of microcapsules is the weight ratio of the core material to the capsule wall material. On the one hand, the goal is to have the highest possible proportion of core material so that the capsule can be as useful as possible, but on the other hand, the capsule must still contain a sufficient proportion of capsule wall material to ensure its stability.

[0358] According to the present invention, it has been found to be particularly advantageous for the microcapsules to be 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.

[0359] Microcapsules produced by the method according to the present invention may be characterized by a size distribution value of d (0.5), that is, 50% of the produced capsules are larger and 50% of the capsules are smaller than this value.

[0360] The microcapsules according to the present invention are prepared from hexamethylene diisocyanate and 4,4'-methyl diphenylene diisocyanate in a 75:25 ratio. Additionally, lysine*HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and arginine as the second amino acid. DABCO was used as a catalyst and modified starch was used as a protective colloid; and beeswax was added as a separating agent.

[0361] To determine the particle size, the microcapsules according to the present invention are dispersed in water as part of a dynamic method, and then the particle size is determined by laser diffraction. Depending on the size of the capsule, the laser beam can be refracted differently and converted into size. For this purpose, Mie theory was used. A MALVERN Mastersizer 3000 was used for particle measurement.

[0362] The microcapsule according to the present invention is characterized by having a particle size distribution with a d(0.5) value of 10 μm to 100 μm, preferably a d(0.5) value of 20 μm to 65 μm. The corresponding particle size distributions of the microcapsule according to the present invention and the microcapsule of the prior art are illustrated in FIG. 2.

[0363] A direct comparison of microcapsules demonstrates that the method according to the present invention can achieve microcapsules having the same particle size distribution as microcapsules of the prior art based on a polyurea / polyurethane structure without a release agent.

[0364] Figure 3 shows IR images of a microcapsule according to the present invention and a microcapsule of the prior art.

[0365] The microcapsule according to the present invention is prepared from hexamethylene diisocyanate and 4,4'-methyl diphenylene diisocyanate in a 75:25 ratio. Additionally, lysine*HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and arginine as the second amino acid. DABCO was used as a catalyst and modified starch was used as a protective colloid; and beeswax was added as a release agent. The microcapsule of the prior art is a polyurea / polyurethane-based microcapsule without a release agent.

[0366] The graph shows a clear difference in the bands, especially in the fingerprint area. 1050 cm -1 Clearly, a more intensive band can be observed when compared to the latest technologies resulting from polyurethane and polyester. Polyester originates from the ester bonds of oxentylsuccinate starch on the one hand, and from the ester bonds of release agents (e.g., waxes) on the other. 1170 cm -1The band can be assigned to polyester. Double vibrations in the range of 2500 to 3000 cm-1 indicate an increased proportion of carbon chains generated from the release agent. A comparison of IR spectra also shows that both the microcapsules according to the present invention and the microcapsules of the prior art are composed of polyurea / polyurethane polymers.

[0367] The method according to the present invention for the production of polyurea / polyurethane microcapsules is particularly characterized by the fact that individual crosslinking steps are performed regardless of the pH value. Accordingly, the method according to the present invention is easier to perform compared to the encapsulation method according to the prior art.

[0368] Although the execution is simpler and shorter, the method according to the present invention enables microcapsules to be produced with better performance, that is, without loss or deterioration of the function of the microcapsules, such as positive characteristics and positive secondary characteristics, such as high stability, i.e., the ability to retain the active ingredient.

[0369] The pH-independent implementation of the crosslinking step also advantageously enables the encapsulation of lipophilic active ingredients having aldehyde, carboxylic acid, or ester functional groups. Using the polyisocyanate-based capsule shell of the prior art, generally only selected active ingredients can be encapsulated. On the other hand, encapsulation using polyisocyanates according to the prior art is not suitable for encapsulating fragrance compounds or fragrance oils having aldehyde, carboxylic acid, or ester functional groups. During encapsulation at an alkaline pH, carboxylic acids are deprotonated, oxidized aldehydes (carboxylic acids) are similarly deprotonated, and esters are saponified, resulting in the loss of lipophilic active ingredients and making the resulting emulsion unstable. Therefore, the use of such microencapsulation is limited in relation to the active ingredient and is thus suitable only for, for example, the small spectrum of fragrance compounds or fragrance oils, but this microencapsulation method is excluded for fragrance compounds or fragrance oils containing aldehyde, carboxylic acid, or ester functional groups. However, fragrance compounds having aldehyde, carboxylic acid, or ester functional groups belong to the most important representatives of fragrance compounds or fragrance oils. In the method according to the present invention, the pH-independent crosslinking step consequently enables the effective encapsulation of such lipophilic fragrances or fragrance oils.

[0370] By the method according to the present invention, it is possible to create a structure of a stable capsule wall or capsule shell by depositing alternatingly defined polyurea and polyurethane-based crosslinking units or a crosslinking matrix around a core containing lipophilic active component(s) by interfacial polymerization. The main component of the capsule shell or capsule wall is basically a polyurea or polyurethane crosslinking matrix or a crosslinking unit. Additionally, a protective colloid (e.g., starch) may be present in the capsule shell or capsule wall through polyurethane linkages. Incorporating a release agent into the capsule shell or capsule wall further stabilizes the capsule shell or capsule wall.

[0371] In addition, the method according to the present invention is characterized by the fact that a protective colloid, an amino acid, a hydroxyl group donor as a main component, and a polyisocyanate are polymerized and / or crosslinked through a mechanism preferably specifically catalyzed to enable the production of biodegradable microcapsules based on bio-based and biocompatible polymers. Unlike microcapsules of the prior art in which the polyisocyanate constitutes a large portion of the capsule shell material, the opposite is true here: the polyisocyanate no longer acts as a main material in the microcapsules according to the present invention but acts only as a crosslinking agent for the amino acid and the other components mentioned above.

[0372] Accordingly, the method according to the present invention enables replacing a portion of the polyisocyanate with biodegradable wall materials, such as protective colloids, amino acids, hydroxyl group donors, and release agents, thereby allowing the polyisocyanate content to be reduced without any loss or deterioration of the function of the microcapsules, such as positive characteristics and positive secondary characteristics, such as high stability, i.e., the ability to retain active ingredients. Thus, the method according to the present invention can be used to produce microcapsules that have excellent functionality on one hand and are easily biodegradable on the other.

[0373] Surprisingly, it has been found that the method according to the present invention can be used to produce microcapsules having an amount of polyisocyanate reduced by up to 60% without loss or degradation of the stability of the obtained microcapsules, as shown in the following embodiments. Thus, microcapsules can be produced by reducing the amount of the starting material isocyanate while maintaining the same amount of the encapsulated active ingredient.

[0374] In another aspect, the present invention relates to biodegradable polyurea / polyurethane microcapsules produced according to the method of the present invention.

[0375] Biodegradable polyurea / polyurethane microcapsules are characterized by being composed of or containing the following:

[0376] (i) a core comprising at least one hydrophobic agent; and

[0377] (ii) A capsule shell containing the following:

[0378] - A reaction product of the polymerization and / or crosslinking of at least one polyisocyanate having two or more isocyanate groups in the presence of at least one protective colloid having at least one first amino acid or amino acid hydrochloride, further polymerization and / or crosslinking with at least one hydroxyl group donor, and further polymerization and / or crosslinking with at least one second amino acid; and

[0379] - At least one release agent.

[0380] Alternate polymerization and / or crosslinking of polyisocyanate units having functional amino or hydroxyl groups produces an alternately defined, dense, and therefore stable crosslinked matrix or a stable capsule wall of polyurethane and polyurea-based crosslinked units.

[0381] In a preferred embodiment, the capsule shell of the biodegradable polyurea / polyurethane microcapsule according to the present invention comprises or is composed of the following:

[0382] (α) A first crosslinking matrix or a first crosslinking unit from the polymerization and / or crosslinking of at least one polyisocyanate having two or more polyisocyanate groups together with at least one protective colloid and at least one first amino acid;

[0383] (β) A second crosslinking matrix or a second crosslinking unit from a crosslink between at least one polyisocyanate having two or more polyisocyanate groups and at least one hydroxyl group donor;

[0384] (γ) A third crosslinking matrix or a third crosslinking unit from a crosslinking of at least one polyisocyanate having two or more polyisocyanate groups and at least one second amino acid; and

[0385] (δ) At least one release agent.

[0386] The first cross-linking matrix or cross-linking unit of the capsule shell of the microcapsule according to the present invention is a polyurea-based network. The second cross-linking matrix or cross-linking unit is a polyurethane-based network, and the third cross-linking matrix or cross-linking unit is an additional polyurea-based network. The composition of the polyurea and polyurethane cross-linking matrix or cross-linking unit depends on the polyisocyanate and cross-linking agent used, namely the protective colloid, the first amino acid, the hydroxyl group donor, and the second amino acid.

[0387] In addition to the polyurethane and polyurea formation described above, the crosslinking step described above generates by-products, such as the aforementioned urea, allophanate, biuret, urethidion, carbodiimide, uretone ion, etc., due to the reactivity of the polyisocyanate, as described in the literature incorporated herein by reference [MF Sonnenschein, Introduction to Polyurethane Chemistry, Polyurethanes: Science, Technology, Markets, and Trends, First Edition, 2015, John Wiley & Sons, pages 105 to 126], in its entirety. These by-products are part of the capsule shell or capsule wall.

[0388] Due to the structure of the capsule wall, particularly stable microcapsules with excellent sensory performance can be produced based on several individually defined and alternating cross-linking matrices or units, while simultaneously enabling a significant reduction in shell components. Finally, the incorporation of a release agent further enhances the stability of the capsule shell.

[0389] Surprisingly, the polyurea / polyurethane fragrance capsules produced according to the method of the present invention exhibit higher stability and a reduction in unwanted escaped fragrance oil, as shown in the following embodiments, which can be attributed particularly to the more efficient encapsulation of the fragrance.

[0390] Surprisingly, it has been found that the method according to the present invention can be used to produce microcapsules that exhibit at least 1.5, preferably at least 2 times, better stability compared to polyurea / polyurethane microcapsules of the prior art, as exemplified in the following embodiments.

[0391] The microcapsule according to the present invention further has a free hydrophobic active substance content of 0.5 weight% or less, preferably ≤ 0.3 weight% or less, more preferably ≤ 0.2 weight%.

[0392] The polyurea / polyurethane microcapsules according to the present invention also exhibit a significant improvement in sensory performance (fragrance release) compared to prior art capsules, which can be attributed to the stable encapsulation of the active ingredient and the associated low loss of the active ingredient. Accordingly, the microcapsules according to the present invention exhibit a significantly higher sensory intensity when the fragrance is released by opening the capsule by mechanical friction or pressure, as shown in FIG. 5. The polyurea / polyurethane microcapsules according to the present invention exhibit a significant improvement in sensory performance (fragrance release) of at least 1.5 times, preferably at least 1.75 times, and much more preferably at least 2 times compared to the capsules of the prior art.

[0393] As the degree of crosslinking increases, that is, as the polyisocyanate content increases, the stability of the microcapsules increases, but at the same time, as exemplified in the embodiments, the ability to biodegrade the capsule shell decreases. Figure 6 generally shows the correlation between microcapsule stability, performance, and biodegradability as a function of the degree of crosslinking. For example, in the case of very stable microcapsules, performance, e.g., sensory performance, decreases as the number of microcapsules that break and release the active ingredient decreases through processes such as rubbing or applying pressure.

[0394] The polyurea / polyurethane microcapsules according to the present invention have an amount of polyisocyanate reduced by up to 60% compared to the polyurea / polyurethane microcapsules of the prior art, without any loss or degradation of the loading or stability of the microcapsules having the encapsulated active ingredient as shown in the embodiments below. In contrast to the microcapsules of the prior art, the isocyanate no longer functions as a major material of the capsule shell or capsule wall, but only acts as a crosslinking agent for the amino acid and other major components of the capsule shell, such as protective colloids and other major components of the hydroxyl group donor. The absolute polyisocyanate content of the microcapsules described herein is only 1 / 60 of the total capsule containing the active ingredient(s). Assuming the raw materials react quantitatively, in the case of 100% wall material, it can be assumed that exactly 1 / 5 of the wall material consists of polyisocyanate, and since the indicated amount is small, it can be considered only as a crosslinking agent.

[0395] Due to the lower polyisocyanate content of the capsule shell or capsule wall and the use of a release agent, the microcapsules according to the present invention are more biodegradable than capsules of the prior art. Microcapsules according to the present invention produced using a release agent exhibit significantly superior biodegradability, as shown in the following embodiments.

[0396] Biodegradability is the ability of organic material to decompose into water, carbon dioxide (CO2), and biomass after a specified period of time under specified temperature, oxygen, and humidity conditions in which microorganisms or fungi are present.

[0397] According to OECD 301F, microcapsules are considered to be immediately biodegradable if more than 60% of the wall material decomposes after 28 days.

[0398] The microcapsule according to the present invention has a biodegradability of ≥ 20% after 28 days according to OECD 301 F, preferably ≥ 50%, much more preferably ≥ 70%, and most preferably ≥ 90%.

[0399] In addition, the microcapsule according to the present invention is a universal capsule capable of encapsulating a wide range of fragrance compounds or flavoring agents, and even fragrance compounds or flavoring agents having aldehydes, carboxylic acids, or esters, according to current state-of-the-art technology, so as not to limit individual active ingredients.

[0400] Due to its advantageous properties, particularly its stability and targeted release of active ingredients, the microcapsule according to the present invention is suitable for a wide range of applications, particularly in household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters, fragrance lotions and fragrance enhancers, cosmetics, personal care products, crops, pharmaceutical products, printing coatings for paper, etc.

[0401] Accordingly, in an additional aspect, the present invention relates to the use of biodegradable polyurea / polyurethane microcapsules according to the present invention or dispersions of polyurea / polyurethane microcapsules according to the present invention for the manufacture of household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters in liquid or solid form, fragrance lotions or fragrance enhancers, cosmetics, personal care products, crops, pharmaceutical products, printing coatings for paper, etc.

[0402] Finally, the present invention relates to household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters, fragrance lotions and fragrance enhancers, cosmetics, personal care products, crops, pharmaceutical products, printing coatings for paper, etc., comprising biodegradable polyurea / polyurethane microcapsules according to the present invention or a dispersion of polyurea / polyurethane microcapsules according to the present invention.

[0403] Implementation Example

[0404] The biodegradable polyurea / polyurethane microcapsules according to the present invention and their advantageous properties are described in more detail with reference to the following examples.

[0405] Implementation Example No. 1 - Wall Material Comparison

[0406]

[0407] The microcapsules according to the present invention have a significantly low polyisocyanate content of up to 60%. In contrast to microcapsules of the prior art, the isocyanate no longer acts as a major substance but is used only as a crosslinking agent for amino acids and other components of the capsule material.

[0408] Implementation Example No. 2 - Capsule Stability

[0409] The following stability data represents tests at 40°C in commercial formulations such as fragrance boosters or fabric softeners.

[0410] Capsules in which the capsule wall consists exclusively of a polyurea network were selected as prior art capsules. For the preparation of these capsules, synthesis was carried out at pH 9 without the use of a catalyst. Polyvinyl alcohol was used as a protective colloid.

[0411] Free oil was measured by leaving the slurry in isopropanol for 30 seconds. Then, the oil content was determined using SPME.

[0412] Example 1 - Capsule stability according to release agent

[0413] The behavior of free oil was determined by varying the release agent. The microcapsules according to the present invention were prepared using an isocyanate mixture consisting of hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Additionally, lysine*HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and arginine as the second amino acid. DABCO was used as a catalyst, and modified starch was used as a protective colloid. TomCap was used in the encapsulation step. The waxes used are listed in the table below. The starch used is in the succinate form.

[0414]

[0415] Clearly, the use of wax improves resistance to extraction solvents. Capsules are considered stable at < 1% free oil. The lower the free oil content, the more stable the capsule.

[0416] Example 2 - Capsule stability as a function of polyisocyanate compositions (comparison of a single polyisocyanate and a combination of two different polyisocyanates)

[0417] The microcapsules according to the present invention were prepared using a different single polyisocyanate or a combination of two different polyisocyanates, guanidinium carbonate, and polyvinyl alcohol as a protective colloid, together with TomCap as a fragrance oil:

[0418]

[0419] Using a combination of two different isocyanates produces microcapsules that exceed the stability of a single isocyanate system. Therefore, it is preferable to use a mixture of two different isocyanates.

[0420] Example 3 - Capsule stability as a function of polyisocyanate compositions (Comparison of aliphatic-aliphatic polyisocyanate mixtures and aliphatic-aromatic polyisocyanate mixtures)

[0421] Microcapsules according to the present invention were prepared as follows using an aliphatic-aliphatic polyisocyanate mixture and an aliphatic-aromatic polyisocyanate mixture:

[0422] Aliphatic-aliphatic polyisocyanate mixture: 50:50 ratio of pentamethylene diisocyanate and hexamethylene diisocyanate.

[0423] Aliphatic-aromatic isocyanate mixture: hexamethylene diisocyanate and 4,4'-methyl diphenylene diisocyanate in a ratio of 75:25.

[0424] In addition, lysine*HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and arginine as the second amino acid. DABCO was used as a catalyst, and modified starch was used as a protective colloid. TomCap was used as the encapsulation step. Beeswax was used as the wax. The starch used was in the succinate form.

[0425]

[0426] The free oil content of both samples is less than 1%, which means that both capsules are considered stable. Microcapsules made from an aliphatic-aliphatic polyisocyanate mixture are as stable as microcapsules made from an aliphatic-aromatic polyisocyanate mixture.

[0427] Implementation Example No. 3 - Biodegradability and free oil related to the amount of crosslinking agent (isocyanate)

[0428] The free oil content was measured as described above.

[0429] Biodegradability according to OECD 301F was determined as follows: the degradability of wall material in an unadapted inoculum measured by manometric respiration (oxygen consumption).

[0430]

[0431] As the amount of isocyanate (crosslinking agent) decreases, biodegradability increases. What is surprising in this case is that the increase in free oil is very small, which implies that the capsule can be presumed to be stable.

[0432] Implementation Example No. 4 - Comparison of Biodegradability According to the Presence or Absence of Release Agent

[0433]

[0434] The capsule according to the present invention indicates that it has 96% biodegradability, which means that the wall material can be presumed to be immediately biodegradable.

[0435] Implementation Example No. 6 - Comparison of Biodegradability Related to Sodium Sulfate and Toxicity Control

[0436] The biodegradability of the wall material was tested according to OECD 301 F with the microcapsules of Embodiment Example No. 5 according to the present invention. For this purpose, sodium benzoate was used as a method control, and a mixture of the microcapsules according to the present invention and sodium benzoate was used as a toxicity control.

[0437] Test replicas 1 and 2 = capsules according to the present invention

[0438] Procedure Control Duplicates 1 and 2 = Sodium Sulfate

[0439] Toxicity control = A combination of a capsule and sodium sulfate according to the present invention for controlling toxic effects.

[0440] The test results are shown in Figure 4.

[0441] The capsule according to the present invention shows an average biodegradability of 96% of two samples, which means that the wall material can be presumed to be immediately biodegradable. Toxicity control also indicates degradability, which demonstrates that the wall material of the capsule according to the present invention is not persistent.

[0442] Implementation Example No. 7 - Comparison of Biodegradability According to the Presence or Absence of Wax

[0443] The microcapsules according to the present invention were prepared using an isocyanate mixture composed of hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Additionally, lysine*HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and arginine as the second amino acid. DABCO was used as a catalyst, and modified starch was used as a protective colloid. Subsequently, the wall material was separated using a centrifuge, a rotary evaporator, and a vacuum drying oven. Ethyl acetate was used as the phase for encapsulation. The waxes used are shown in the table below. The starch used is in the succinate form.

[0444]

[0445] According to OECD 301F, both capsules are considered biodegradable due to the use of wax. The use of wax is surprising in that biodegradability increases disproportionately despite the small amount of wax.

[0446] Implementation Example No. 8 - Sensory Test

[0447] For sensory evaluation, the microcapsules according to the present invention were compared with microcapsules of the prior art, namely, microcapsules based on a polyurea / polyurethane structure without a release agent.

[0448] Microcapsules are prepared from hexamethylene diisocyanate and 4,4'-methyl diphenylene diisocyanate in a 75:25 ratio. Additionally, lysine*HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and arginine as the second amino acid. DABCO was used as a catalyst, modified starch was used as a protective colloid, and beeswax was added as a separating agent.

[0449] Sensory evaluation was performed as follows: the above microcapsules were each added to a fabric softener with an oil concentration of 0.2 wt% and then washed. Odor testing was performed on a mixed fiber fabric made of cotton and polyester.

[0450] Twelve test participants rated the scent intensity of the blended fiber fabric after washing on a scale from 1 (no scent) to 9 (very strong scent). The scent rating consisted of three stages. Stage 1 describes the scent of the untreated fabric. Stage 2 describes the scent of the lightly kneaded fabric; to do this, the fabric was moved back and forth several times between the hands to apply slight mechanical stress and break the capsules. Stage 3 describes the scent that emerges after the capsules are broken by rubbing the fabric vigorously.

[0451] The microcapsules according to the present invention have much better performance as shown in FIG. 5. This can be attributed to a specific modification of the system, as the capsule adheres better and has a better odor due to the formation of a shell structure defined by the deposition of different polymers of crosslinking units and the use of a release agent.

Claims

Claim 1 A method for manufacturing biodegradable polyurea / polyurethane microcapsules, comprising the following steps in order: (a) performing a first polymerization and / or crosslinking step comprising: (a1) providing an inner non-aqueous phase comprising at least one polyisocyanate having two or more isocyanate groups and at least one lipophilic active substance to be encapsulated; (a2) providing an outer aqueous phase comprising at least one protective colloid; (a3) ​​mixing the inner non-aqueous phase and the outer aqueous phase to obtain an oil-in-water emulsion; (a4) adding at least one first amino acid or amino acid hydrochloride and a catalyst; (b) performing a second polymerization and / or crosslinking step by adding at least one hydroxyl group donor; (c) performing a third polymerization and / or crosslinking step by adding at least one second amino acid to obtain a microcapsule dispersion; (d) curing the microcapsule dispersion at a temperature of at least 60°C for a period of at least 60 minutes. (e) adding at least one release agent and incorporating the release agent into the microcapsule shell; (f) post-curing the polyurea microcapsule obtained in step (e); the at least one release agent is selected from the group consisting of: - a long-chain, aliphatic, linear or branched, saturated or unsaturated carboxylic acid having 12 to 30 carbon atoms (fatty acid); - a long-chain, aliphatic, linear or branched, saturated or unsaturated primary alcohol having 12 to 30 carbon atoms (fatty alcohol); - an ester of a long-chain, aliphatic saturated carboxylic acid having 12 to 30 carbon atoms and a long-chain, aliphatic primary alcohol having 12 to 30 carbon atoms; and - animal and vegetable waxes; and a mixture of the aforementioned release agent. Claim 2 A method according to claim 1, wherein an emulsifier is additionally provided in step (a2). Claim 3 The method of claim 1, wherein the method further comprises the step (g) of separating microcapsules from a microcapsule dispersion and drying said microcapsules. Claim 4 A method according to claim 1, wherein at least one polyisocyanate having two or more isocyanate groups is selected from the group consisting of aliphatic, alicyclic, hydroaromatic, aromatic, or heterocyclic polyisocyanate substitution products as well as mixtures of the aforementioned compounds. Claim 5 The method according to claim 1, wherein at least one lipophilic active substance to be encapsulated is selected from the group consisting of fragrance compounds, flavoring agents, refreshing agents, TRPV1 and TRPV3 modifiers, substances that cause a stimulating taste or a sensation of warmth or heat on the skin or mucous membranes or a tingling sensation in the mouth or throat, or active substances having a stimulating, spicy, or stinging effect, substances of the group of pesticides, biocides, insecticides, and repellents, food additives, cosmetic active ingredients, pharmaceutical active ingredients, dyes, dye precursors, pesticides, dyes, luminescent paints, photobrightening agents, solvents, waxes, silicone oils, lubricants, materials for printing coatings on paper, and mixtures of two or more of the aforementioned active ingredients. Claim 6 A method according to claim 1, wherein at least one lipophilic active ingredient to be encapsulated is selected from the group consisting of aldehydes, carboxylic acids, fragrance compounds or flavor agents having ester functional groups. Claim 7 In claim 1, the protective colloid is selected from the group consisting of: diols, and - polyols, - polyvinylpyrrolidone, vinyl maleate copolymer, sodium lignosulfonate, maleic anhydride / styrene copolymer, ethylene / maleic anhydride copolymer, ethylene oxide, copolymer of acid esters of propylene oxide and polyethoxylated sorbitol, sodium dodecyl sulfate, - animal and plant polymers, as well as mixtures of the aforementioned compounds. Claim 8 A method according to claim 1, wherein the protective colloid is used in combination with starch. Claim 9 The method of claim 1, wherein at least one first amino acid is selected from the group consisting of arginine, histidine, lysine, tryptophan, ornithine, arginine hydrochloride, histidine hydrochloride, lysine hydrochloride, tryptophan hydrochloride, ornithine hydrochloride, and mixtures thereof. Claim 10 A method according to claim 1, wherein the catalyst is selected from the group consisting of diazabicyclo[2.2.2]octane (DABCO), bismuth catalyst, tin catalyst, and mixtures thereof. Claim 11 The method according to claim 1, wherein the hydroxyl group donor is a polyol having two or more hydroxyl functional groups. Claim 12 The method according to claim 1, wherein 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, and mixtures thereof. Claim 13 Biodegradable polyurea / polyurethane microcapsules obtainable by the method of claim 1. Claim 14 A biodegradable polyurea / polyurethane microcapsule dispersion obtainable by the method of claim 1, wherein the microcapsule dispersion is a microcapsule dispersion obtained after step (f) of claim 1 is completed. Claim 15 Biodegradable polyurea / polyurethane microcapsules comprising: (i) a core comprising at least one hydrophobic agent; and (ii) a capsule shell comprising: - a reaction product of polymerization and / or crosslinking of at least one polyisocyanate having two or more isocyanate groups in the presence of a protective colloid having at least one first amino acid or amino acid hydrochloride, further polymerization and / or crosslinking with at least one hydroxyl group donor, and further polymerization and / or crosslinking with at least one second amino acid; and - at least one release agent. Claim 16 In claim 15, the capsule shell comprises a biodegradable polyurea / polyurethane microcapsule comprising: (α) a first crosslinking matrix or a first crosslinking unit from 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; (β) a second crosslinking matrix or a second crosslinking unit from the crosslinking of at least one polyisocyanate having two or more isocyanate groups with at least one hydroxyl group donor; (γ) a third crosslinking matrix or a third crosslinking unit from the crosslinking of at least one polyisocyanate having two or more isocyanate groups with at least one second amino acid; and (δ) at least one release agent. Claim 17 In paragraph 13, biodegradable polyurea / polyurethane microcapsules having biodegradability according to OECD 301 F of ≥ 20% after 28 days and a free hydrophobic active ingredient content of ≤3% by weight. Claim 18 Biodegradable polyurea / polyurethane microcapsules according to claim 13 for use in the manufacture of household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters, fragrance lotions or fragrance enhancers in liquid or solid form, cosmetics, personal care products, perfume compositions, crops, pharmaceutical products or printing coatings for paper. Claim 19 A biodegradable polyurea / polyurethane microcapsule dispersion according to claim 14 for use in the manufacture of household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters, fragrance lotions or fragrance enhancers in liquid or solid form, cosmetics, personal care products, perfume compositions, crops, pharmaceutical products or printing coatings for paper. Claim 20 delete

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