Biodegradable polyurea / polyurethane microcapsules

Description

[0001] The present invention relates to a process for producing biodegradable polyurea / polyurethane microcapsules enclosing at least one lipophilic active ingredient, preferably perfume- or aroma-containing polyurea / polyurethane microcapsules, which exhibit a balanced ratio of biodegradability, stability, and performance compared to prior art microcapsules. Furthermore, the present invention relates to biodegradable polyurea / polyurethane microcapsules comprising at least one lipophilic active ingredient, obtained according to the process of the invention.In another aspect, the invention described herein relates to the use of such microcapsules or microcapsule dispersions comprising the microcapsules according to the invention for the manufacture of household products, textile care products, detergents, fabric softeners, cleaning agents, scent boosters, scent lotions or fragrance enhancers, cosmetics, personal care products, agricultural products, pharmaceutical products, or printing coatings for paper. Finally, the present invention relates to consumer products comprising such microcapsules or microcapsule dispersions.

[0002] Microcapsules are particles consisting of a core and a surrounding wall material. The core can be a solid, liquid, or gaseous substance, surrounded by a polymeric, dense, permeable, or semipermeable wall material. During production, the polymers from the starting materials, after emulsification and coacervation or interfacial polymerization, deposit onto the substances to be encapsulated, thereby immobilizing them. The core is also referred to as the inner phase. The wall is also known as the outer phase, shell, or coating. The diameter of microcapsules typically ranges from 1 to 1000 µm. The wall thickness is typically 0.5 to 150 µm. Loadings of 25 to 95 wt% are typical, but those of 1 to 99 wt% are also possible.

[0003] The aims of encapsulation include protecting the encapsulated active substances or ingredients, releasing them in a controlled manner at a specific time, converting liquids into a manageable powder form, delaying the loss of volatile components (e.g., in the case of fragrances or flavorings), preventing premature chemical reactions with other mixture components, and ensuring better handling before or during processing. Hydrophobic active ingredients, such as fragrances or flavorings, can be easily incorporated into numerous and diverse application formulations through encapsulation.

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

[0005] A wide variety of shell materials are known for the production of microcapsules. The shell can consist of natural, semi-synthetic, or synthetic materials. Examples of natural shell materials include gum arabic, agar-agar, agarose, maltodextrins, alginic acid or its salts (e.g., sodium alginate or calcium alginate), fats and fatty acids, cetyl alcohol, collagen, chitosan, lecithins, gelatin, albumin, shellac, polysaccharides such as starch or dextran, polypeptides, protein hydrolysates, sucrose, and waxes. Semi-synthetic shell materials include chemically modified celluloses, particularly cellulose esters and cellulose ethers (e.g., cellulose acetate, ethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, and carboxymethylcellulose), as well as starch derivatives (especially starch ethers and starch esters).Synthetic shell materials include polymers such as polyacrylates, polyamides, polyvinyl alcohol, or polyvinylpyrrolidone.

[0006] Depending on the type of shell material and manufacturing process, microcapsules with different properties regarding diameter, size distribution, and physical and / or chemical properties are produced.

[0007] Polyurea microcapsules or polyurea / polyurethane microcapsules formed by polymerization between a polyisocyanate and a polyamine and / or a diol or polyol are well-known capsules used in a variety of technical fields, including perfumery.

[0008] Polyurea microcapsules obtained by reacting two polyisocyanates and a polyamine are described, for example, in WO 2011 / 161229 and WO 2011 / 160733. According to WO 2011 / 161229 and WO 2011 / 160733, the polyurea microcapsules are produced in the presence of polyvinylpyrrolidone (PVP) as a protective colloid. WO 2012 / 107323 discloses polyurea microcapsules with a polyurea shell comprising the reaction product of a polyisocyanate with guanazole (3,5-diamino-1,2,4-triazole) and an amino acid in the presence of anionic stabilizers or surfactants such as anionic polyvinyl alcohol. EP 0 537 467 B describes microcapsules produced from polyisocyanates containing polyethylene oxide groups in the presence of stabilizers such as polyvinyl alcohol.According to WO 2007 / 096592, microencapsulation can take place in an oil phase which is emulsified in a continuous aqueous phase which is generally stabilized by a surfactant system such as polyvinyl alcohols or carboxylated and sulfonated derivatives thereof.

[0009] The exemplary delivery systems described above from the prior art exhibit both good stability, namely the ability to retain the active ingredient and thus the ability of the capsules to avoid the loss of volatile components, and good performance, for example fragrance release in the case of fragrance capsules.

[0010] However, the state-of-the-art microcapsules described above have the disadvantage that the polymeric capsule wall or capsule shell material requires a high polymer content to ensure sufficient stability and prevent excessive loss of the active ingredient. Furthermore, microencapsulation releases plastic into the environment, where it can cause problems as "microplastics".

[0011] Because plastic particles are increasingly criticized for their environmental impact, and the demand for bio-based and biodegradable solutions is growing due to steadily increasing societal pressure regarding environmental concerns, there is a need to develop new materials for microencapsulation to reduce microplastics in the environment. Bio-based and biodegradable materials are the focus here.

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

[0013] However, this task of reducing the amount of microplastics in the environment using biodegradable materials is not trivial in the case of microencapsulations, since the desired functionality of the microcapsule, such as olfactory properties and positive secondary properties such as high stability and toxicological stability, often conflicts with the requirements for rapid biodegradability in many applications.

[0014] It is particularly difficult to manufacture microcapsules that exhibit both good stability and good drug release. The ability to retain the active ingredient, and thus the capsules' ability to prevent the loss of volatile components, depends primarily on the capsules' stability within the product base. However, capsules with good stability do not automatically guarantee good biodegradability.

[0015] As the degree of cross-linking increases, the stability of the microcapsules also increases, but at the same time, the biodegradability of the capsule shell decreases. With very stable microcapsules, performance, such as sensory performance, is lower because the number of microcapsules that rupture due to pressure, friction, etc., and release active ingredients, decreases. If they are too unstable, they are destroyed during storage and therefore also do not perform as expected.

[0016] WO2018 / 06089 A1 discloses stable microcapsule compositions comprising microcapsules dispersed in an aqueous phase and a stabilizing agent that is a combination of a negatively charged clay and a cationic polymer. The microcapsule compositions are stable, i.e., they do not gel and no separation occurs, when stored at 45 °C for at least 4 weeks. The invention also relates to consumer products containing such stable microcapsule compositions, as well as methods for producing the microcapsules and compositions.

[0017] Against this background, the present invention was based on the complex problem of providing a method for the production of microcapsules which, on the one hand, makes it possible to provide microcapsules with a lower polymer content, which at the same time have a balanced ratio of high stability as well as excellent release behavior of the encapsulated active ingredients and good biodegradable properties.

[0018] Surprisingly, it was found that this problem can be solved by producing polyurea / polyurethane microcapsules using amino acids and a release agent that integrates into the microcapsule shell. By precisely adjusting the pH during emulsification and cross-linking, the stability and sensory performance of the microcapsules can be further improved and optimized. The optional use of a second catalyst allows for the creation of microcapsules with even greater stability and performance. Summary of the invention

[0019] The problem at hand is solved by the subject matter of the independent patent claims. Preferred embodiments are described in the dependent patent claims and the following description.

[0020] A first object of the present invention therefore relates to a method for producing a biodegradable polyurea / polyurethane microcapsule, which comprises the following steps in this order: (a) Performing a first polymerization and / or crosslinking step, comprising: (a1) providing an internal non-aqueous phase comprising at least one polyisocyanate with two or more isocyanate groups and at least one lipophilic active ingredient to be encapsulated; (a2) providing an external aqueous phase comprising at least one protective colloid and optionally an emulsifier, and adjusting the pH of the aqueous phase to a pH of 1 to 5; (a3) ​​mixing the internal non-aqueous phase and the external aqueous phase to obtain an oil-in-water emulsion or dispersion; (a4) adding at least one first amino acid or amino acid hydrochloride and a first catalyst and adjusting the pH of the emulsion or dispersion.Dispersion to a pH of 4 to 8; (b) carrying out a second polymerization and / or crosslinking step by adding at least one hydroxyl group donor; (c) carrying out a third polymerization and / or crosslinking step by adding at least one second amino acid and adjusting the pH of the emulsion or(d) Dispersion to a pH of 4 to 8, in particular at a temperature of at least 60 °C, to obtain a microcapsule dispersion; (e) optionally, addition of a further catalyst and adjustment of the pH of the microcapsule dispersion to a pH of 4 to 7; (e) Curing of the microcapsule dispersion obtained from step (c) or (d) at a temperature of at least 60 °C for a period of at least 60 minutes; (f) Addition of at least one release agent and incorporation of the release agent into the microcapsule shell; (g) Post-curing of the microcapsule obtained in step (f); and (h) optionally, separation of the microcapsule from the microcapsule dispersion and, if necessary, drying of the microcapsule or adjustment of the viscosity of the microcapsule slurry by adding a thickening agent.

[0021] Furthermore, the invention described herein relates to a biodegradable polyurea / polyurethane microcapsule or polyurea / polyurethane microcapsule dispersion obtained according to the method of the invention, wherein the microcapsule comprises: (i) a core comprising at least one lipophilic active ingredient; and (ii) a hardened capsule shell comprising a reaction product of a polymerization and / or crosslinking of at least one polyisocyanate with two or more isocyanate groups, in the presence of at least one protective colloid with at least one first amino acid or an amino acid hydrochloride, a further polymerization and / or crosslinking with at least one hydroxyl group donor, and a further polymerization and / or crosslinking with at least one second amino acid, wherein the alternating polymerization and / or crosslinking of polyisocyanate units with functional amino groups orHydroxyl groups in a stable capsule shell resulting from alternately defined and dense crosslinking units based on polyurethane and polyurea, which are spatially crosslinked with each other and with each other; and at least one release agent.

[0022] Another aspect of the present disclosure is a biodegradable polyurea / polyurethane microcapsule comprising (i) a core comprising at least one hydrophobic active ingredient; and (ii) a capsule shell comprising: a reaction product of a polymerization and / or crosslinking of at least one polyisocyanate with two or more isocyanate groups, in the presence of at least one protective colloid comprising at least one first amino acid or an amino acid hydrochloride, a further polymerization and / or crosslinking with at least one hydroxyl group donor, and a further polymerization and / or crosslinking with at least one second amino acid; and at least one separating agent.

[0023] Finally, in a further aspect, the present invention relates to the use of the biodegradable polyurea / polyurethane microcapsule or a dispersion of the polyurea / polyurethane microcapsules according to the invention for the manufacture of household products, textile care products, detergents, fabric softeners, cleaning agents, scent boosters, scent lotions or fragrance enhancers, cosmetics, personal care products, perfume compositions, agricultural products, pharmaceutical products or printing coatings for paper, as well as the consumer products manufactured therefrom.

[0024] Surprisingly, it was found within the scope of the present invention that the production of the microcapsules involves the combination of targeted polymerization and / or crosslinking of polyisocyanates with at least two or more isocyanate groups with a first amino acid or an amino acid hydrochloride, subsequent polymerization and / or crosslinking with a hydroxyl group donor, further polymerization and / or crosslinking with a second amino acid, the addition of a release agent, incorporation of the release agent into the microcapsule shell, and targeted pH adjustment of the emulsion.Dispersion at the beginning of emulsification and at the beginning of the respective cross-linking reactions leads to stable microcapsules, thus ensuring efficient encapsulation of lipophilic active ingredients with subsequent targeted release of these active ingredients, while the microcapsules simultaneously exhibit good biodegradability due to their bio-based and biodegradable building blocks, such as amino acids and separating agents.

[0025] Furthermore, the use of amino acids and a release agent allows the polyisocyanate polymer content of the capsule wall or capsule shell material to be reduced, i.e., replaced by bio-based capsule wall components, without compromising the stability of the microcapsule wall. Incorporating the release agent into the microcapsule shell also facilitates the biodegradability of the capsule wall or capsule shell material.

[0026] These and other aspects, features, and advantages of the present invention will become apparent to the person skilled in the art upon study of the following detailed description and the claims. Any feature from one aspect of the invention can be used or substituted in another aspect of the invention. The examples contained herein illustrate the invention without limiting it.

[0027] The terms "at least one" or "at least one" or "one or more", as used herein, refer to 1 or more, for example 2, 3, 4, 5, 6, 7, 8, 9 or more.

[0028] The term "and / or" expresses that a connection exists or an alternative is offered.

[0029] Numerical examples given in the form "x to y" include the specified values. If multiple preferred numerical ranges are given in this format, all ranges resulting from the combination of the different endpoints are also included. Figures

[0030] Figure 1 This is a light microscopic image of the microcapsules according to the invention. The microcapsules were produced from hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Furthermore, lysine HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and histidine as the second amino acid. DABCO was used as the catalyst, and a modified starch as the protective colloid; beeswax was added as a separating agent. An Olympus BX51 microscope was used for the light microscopic image. The bar shown corresponds to 50 µm.

[0031] Figure 2Figure 1 shows a diagram of the particle size distribution (d(0.5) value) of microcapsules according to the invention and prior art microcapsules based on polyurea / polyurethane structures without a release agent. A MALVERN Mastersizer 3000 was used to determine the particle size distribution. The corresponding calculation is based on Mie theory.

[0032] Figure 3 Figure 1 is a diagram showing the results of an IR spectroscopic analysis of microcapsules according to the invention and prior art microcapsules, i.e., microcapsules based on polyurea / polyurethane structures without a separating agent. The analysis was performed using ATR infrared spectroscopy (Attenuated Total Reflection).

[0033] Figure 4is a diagram that shows the biodegradability of microcapsules according to the invention in accordance with OECD 301 F in comparison to sodium benzoate and a toxicity control (mixture of the microcapsules according to the invention and sodium benzoate).

[0034] Figure 5 is a diagram showing the results of a sensory evaluation of microcapsules according to the invention and prior art microcapsules, i.e., microcapsules based on polyurea / polyurethane structures without separating agents.

[0035] Figure 6 is a diagram that generally shows the correlation between microcapsule stability, performance and biodegradability depending on the degree of cross-linking.

[0036] In each figure, a period is used as the decimal separator. Detailed description of the invention

[0037] In a first aspect, the present invention relates to a method for producing a biodegradable polyurea / polyurethane microcapsule, preferably a method for producing a fragrance or aroma capsule, which comprises the following steps in this order: (a) Performing a first polymerization and / or crosslinking step, comprising: (a1) providing an internal non-aqueous phase comprising at least one polyisocyanate with two or more isocyanate groups and at least one lipophilic active ingredient to be encapsulated; (a2) providing an external aqueous phase comprising at least one protective colloid and optionally an emulsifier, and adjusting the pH of the aqueous phase to a pH of 1 to 5; (a3) ​​mixing the internal non-aqueous phase and the external aqueous phase to obtain an oil-in-water emulsion or dispersion; (a4) adding at least one first amino acid or amino acid hydrochloride and a first catalyst and adjusting the pH of the emulsion or dispersion.Dispersion to a pH of 4 to 8; (b) carrying out a second polymerization and / or crosslinking step by adding at least one hydroxyl group donor; (c) carrying out a third polymerization and / or crosslinking step by adding at least one second amino acid and adjusting the pH of the emulsion or(d) Dispersion to a pH of 4 to 8, in particular at a temperature of at least 60 °C, to obtain a microcapsule dispersion; (e) optionally, addition of a further catalyst and adjustment of the pH of the microcapsule dispersion to a pH of 4 to 7; (e) Curing of the microcapsule dispersion obtained from step (c) or (d) at a temperature of at least 60 °C for a period of at least 60 minutes; (f) Addition of at least one release agent and incorporation of the release agent into the microcapsule shell; (g) Post-curing of the microcapsule obtained in step (f); and (h) optionally, separation of the microcapsule from the microcapsule dispersion and, if necessary, drying of the microcapsule or adjustment of the viscosity of the microcapsule slurry by adding a thickening agent.

[0038] In the context of the present invention, microcapsules are understood to be microparticles comprising a capsule shell or capsule wall and at least one or more active ingredients as core material within the capsule. The active ingredients are preferably lipophilic or hydrophobic. Such active ingredients are insoluble or poorly soluble in water, but readily soluble in fats and oils. The terms "microcapsule" or "capsule" and "lipophilic" or "hydrophobic" are used synonymously within the meaning of the present invention.

[0039] Within the scope of the present invention, the capsule shell or capsule wall is preferably composed of several crosslinking matrices or crosslinking units, which preferably have different compositions and are generated by several process steps or process sequences, in particular crosslinking steps, during the manufacture of the microcapsule according to the invention, so that a three-dimensional network is created.

[0040] In the context of the present invention, a crosslinking matrix or crosslinking unit is a composite or network of starting materials for constructing the microcapsule shell. This matrix or network is formed by linear or three-dimensional polymerization and / or crosslinking between functional groups of the starting materials and / or with other components of the microcapsule shell, and / or it may contain embedded components of the microcapsule shell. Several crosslinking matrices can be further crosslinked together during the process according to the invention to form a three-dimensional structure for constructing the microcapsule shell or microcapsule wall. The crosslinking units or crosslinking matrices collectively constitute the capsule shell or capsule wall.

[0041] In a more preferred embodiment of the present invention, the capsule shell or capsule wall comprises at least polyurea and polyurethane crosslinking matrices or crosslinking units and a release agent embedded in the capsule shell or capsule wall.

[0042] In a first step (a) of the process according to the invention, a first polymerization and / or crosslinking (a) is carried out. For this purpose, an internal non-aqueous phase (a1) is provided, which comprises at least one isocyanate or one polyisocyanate with two or more isocyanate groups and at least one lipophilic active ingredient to be encapsulated.

[0043] The polyurea / polyurethane microcapsules according to the present invention are produced using at least one or more polyisocyanates.

[0044] The at least one isocyanate or polyisocyanate with two or more isocyanate groups, which is used in the process according to the invention for the production of a biodegradable polyurea / polyurethane microcapsule, has at least two isocyanate groups for the formation of polymeric networks by polymerization, which form a capsule shell or capsule wall.

[0045] Polyisocyanates are R-substituted organic derivatives (RN=C=O) of isocyanic acid (HN=C=O). Organic isocyanates are compounds in which the isocyanate group (-N=C=O) is bonded to an organic radical. Polyfunctional isocyanates, or polyisocyanates, are compounds containing at least two or more isocyanate groups (-N=C=O) in the molecule, i.e., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200, or even more. Polyisocyanates with two isocyanate groups are also called diisocyanates.

[0046] Polyisocyanates can be classified into aliphatic, cycloaliphatic, hydroaromatic, aromatic, or heterocyclic isocyanates or polyisocyanates. Furthermore, the polyisocyanates according to the invention can be linear or branched.

[0047] Polyisocyanates, especially aromatic polyisocyanates, are highly reactive compounds. The polyaddition reactions of polyisocyanates with diols or polyols form the basis of polyurethane chemistry, and the polyaddition reactions of polyisocyanates with amines form the basis of polyurea chemistry.

[0048] According to the invention, at least difunctional, preferably polyfunctional polyisocyanates are used, i.e., all aliphatic, alicyclic and aromatic isocyanates are suitable, provided they have at least two reactive isocyanate groups.

[0049] Particularly preferred are aliphatic, cycloaliphatic, hydroaromatic, aromatic, or heterocyclic polyisocyanates, their substitution products, and mixtures of the aforementioned monomeric or oligomeric compounds. Of the polyisocyanates specified above, aliphatic and / or aromatic compounds are preferred.

[0050] In preferred embodiments of the process according to the invention, the polyisocyanate contains an average of 2 to 5 functional -N=C=O groups. These include, for example, aliphatic, cycloaliphatic and aromatic di-, tri- and higher polyisocyanates.

[0051] Among the polyisocyanates mentioned above, diisocyanates and polyisocyanates with three functional -NC=O groups are particularly preferred and are therefore primarily used in the implementation of the present invention. Diisocyanates with the general structure O=C=NRN=C=O are preferred, where R represents aliphatic, alicyclic, or aromatic radicals. Preferably, the radicals have five or more carbon atoms.

[0052] In a preferred embodiment of the process according to the invention, the at least one polyisocyanate with two or more isocyanate groups is selected from the group consisting of aliphatic polyisocyanates and / or aromatic polyisocyanates. In a further preferred embodiment of the process according to the invention, the at least one polyisocyanate is a combination of two different aliphatic polyisocyanates or a combination of an aliphatic and an aromatic polyisocyanate.

[0053] Due to the number of functional groups, optimal cross-linking or networking of the capsule wall is achieved, providing microcapsules that exhibit prolonged slow release of active ingredients and good stability in the consumer product.

[0054] In a preferred embodiment of the process according to the invention, the polyisocyanate is an aliphatic polyisocyanate.

[0055] The term "aliphatic polyisocyanate" refers to any non-aromatic polyisocyanate molecule. Furthermore, the molecule comprises at least two isocyanate groups, i.e., at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200 or more isocyanate groups directly bonded to a corresponding number of different carbon atoms of the same aliphatic molecule, and derivatives of such compounds.

[0056] The aliphatic polyisocyanate molecule, which has 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 furthermore 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.

[0057] 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 comprise an aromatic structure.

[0058] 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, C7- to C8- branched alkyl.

[0059] The shorter the carbon chain of the polyisocyanate molecule, the higher the reaction rate compared to longer-chain analogues.

[0060] The cyclic aliphatic polyisocyanate molecule comprises at least one, i.e., one, two, three, four, or more non-aromatic ring structures, the ring structure itself preferably consisting only of carbon atoms. Naturally, the carbon atoms of the ring structure can bear suitable substituents. The at least one ring structure preferably consists independently of three, four, five, six, seven, or eight-membered rings. Preferably, the cyclic aliphatic molecule comprises two to twenty carbon atoms, such as three to fifteen, four to twelve, five to ten, six to nine, or seven to eight.

[0061] In a further embodiment of the process according to the 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 bonded to aromatic carbon atoms and, for example, comprises a phenyl, tolyl, xylyl, naphthyl, or diphenyl unit as an aromatic component, as well as derivatives of such polyisocyanate compounds.

[0062] Aromatic polyisocyanates react significantly faster than aliphatic polyisocyanates and are therefore preferably used in the process according to the invention.

[0063] Linear, branched, or cyclic aliphatic or aromatic polyisocyanate can exist as a monomer or a polymer. A monomeric polyisocyanate is a molecule that is not linked to another molecule, particularly not by one or more crosslinking agents. A polymeric polyisocyanate comprises at least two monomers linked together by one or more crosslinking agents. The at least two monomers need not necessarily be the same monomers but can also be different. A polymeric polyisocyanate preferably comprises at least two or more monomers, i.e., at least two, three, four, five, ten, twenty, thirty, forty, fifty, one hundred, or more monomers linked together by at least one crosslinking agent.

[0064] The linear, branched, or cyclic aliphatic or aromatic polyisocyanate preferably has a limited size / molecular weight, enabling reactivity with one or more crosslinking agents. Examples of suitable molecular weights preferably include approximately 100 g / mol to 5 × 10⁴ < g / mol, preferably 120 g / mol to 2 × 10⁴ < g / mol, 140 g / mol to 10⁴ < g / mol, 160 g / mol to 5 × 10³ < g / mol, and 180 g / mol to 2 × 10⁴ < g / mol. 10 3< g / mol, 200 g / mol to 10 3< 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.

[0065] Any number of different linear, branched, and / or cyclic aliphatic and / or aromatic polyisocyanates can be used. For example, at least one, i.e., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 different linear aliphatic polyisocyanates are used. For example, at least one, i.e., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 different branched aliphatic polyisocyanates are used. For example, at least one, i.e., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 different branched cyclic polyisocyanates are used.

[0066] Preferably, derivatives of linear, branched, and / or cyclic aliphatic polyisocyanates are used. A derivative, as used here, is understood in its broadest sense as a compound derived from another compound by a chemical reaction. Examples of derivatives include oligomers and / or adducts of the aforementioned linear or branched aliphatic polyisocyanates. Preferred oligomers are biurets, isocyanurates, uretdiones, and iminooxadiazindiones, and preferred adducts are trimethylolpropane adducts. These oligomers / adducts are well known in the prior art and are disclosed, for example, in US 4,855,490 A or US 4,144,268 A.

[0067] Preferably, the aliphatic polyisocyanate is only present in monomeric form and / or dimerized form (as isocyanate) or in oligomeric form.

[0068] The derivatives of linear, branched or cyclic polyisocyanates and / or mixtures thereof can also be obtained by reacting the polyisocyanates with polyalcohols (e.g. glycerol), polyamines, polythiols (e.g. dimercaprol).

[0069] The isocyanate compounds according to the above definition explicitly include the various isomers, if any, 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).

[0070] Examples of aliphatic polyisocyanates include those that are commercially available, 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, polyfunctional aliphatic polyisocyanates based on hexamethylene diisocyanate; and DESMODUR 3600 and DESMODUR N100, which are aliphatic polyisocyanates based on hexamethylene diisocyanate, each of which is available from Bayer Corporation, Pittsburgh, PA.

[0071] According to another preferred embodiment of the present invention, the linear or branched aliphatic polyisocyanates are selected from the group consisting of pentamethylene diisocyanate (PDI, such as Stabio D-370N or D-376N from Mitsui Chemicals Inc., Japan), hexamethylene diisocyanate (HDI), ethyl lysine triisocyanate, ethyl lysine diisocyanate, and derivatives thereof, preferably wherein each of the derivatives comprises more than one isocyanate group and optionally further comprises one or more groups selected from the group consisting of biuret, isocyanurate, uretdione, iminooxadiazine, and trimethylolpropane adduct, and / or wherein the cyclic aliphatic polyisocyanate(s) are selected from the group consisting of isophorone diisocyanate (IPDI), 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI, such as Takenate 600 from Mitsui Chemicals Inc., Japan). Inc., Japan), 1,2-Bis(isocyanatomethyl)cyclohexane, 1,4-Bis(isocyanatomethyl)cyclohexane, methylenebis(cyclohexyl isocyanate) ) (H12MDI) and derivatives thereof, preferably wherein each of the derivatives comprises more than one isocyanate group and optionally further comprises one or more groups selected from the group consisting of biuret, isocyanurate, uretdione, iminooxadiazine ion and trimethylolpropane adduct (such as TMP adduct) of H6XDI, in particular Takenate D-120N from Mitsui Chemicals Inc., Japan).

[0072] Aliphatic polyisocyanates derived from renewable resources such as PDI (Stabio D-370N or D-376N from Mitsui Chemicals Inc., Japan) are particularly preferred. It has been found that such aliphatic polyisocyanates obtained from renewable resources do not impair the quality / properties of the core-shell capsules.

[0073] Other suitable commercially available polyisocyanates include LUPRANAT M20 (BASF), with an average n of 0.7; PA PI 27 (Dow Chemical), with an average n of 0.7; MONDUR MR (Bayer), with an average n of 0.8; MONDUR MR Light (Bayer), with an average n of 0.8; MONDUR 489 (Bayer), with an average n of 1.0; poly-[(phenylisocyanate)-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 are TAKENATE D-1 10N (Mitsui), DESMODUR L75 (Bayer), and DESMODUR IL (Bayer).

[0074] In a preferred embodiment, the polyisocyanate used in the manufacture of the polyurea / polyurethane microcapsules according to the present invention is used as the sole polyisocyanate component, i.e., without the addition of any other polyisocyanate component.

[0075] Examples of monomeric polyisocyanates that can be used according to the invention, which contain at least two polyisocyanate groups, are: 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, mixtures of 1,3-phenylene diisocyanate and 1,4-phenylene diisocyanate, p-phenylene diisothiocyanate, xylylene 1,4-diisothiocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, mixtures of 2,4-toluene diisocyanate and 2,6-Toluene diisocyanate, xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate and mixtures of xylylene-1,4-diisocyanate and xylylene-1,3-diisocyanate, 2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate, mixtures of 2,4-hexahydrotoluene diisocyanate and 2,6-hexahydrotoluene diisocyanate, hexahydro-1,3-phenylene diisocyanate,Hexahydro-1,4-phenylene diisocyanate, mixtures of hexahydro-1,4-phenylene diisocyanate and hexahydro-1,4-phenylene diisocyanate, 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 mixtures of the aforementioned compounds.

[0076] Polymerizable compounds containing at least two polyisocyanate groups are preferably industrially produced di- and polyisocyanates, for example TDI: toluene diisocyanate (isomer mixture of 2,4- and 2,6-toluene diisocyanate in a ratio of 80 : 20), HDI: hexamethylene diisocyanate-(1,6), IPDI: isophorone diisocyanate or DMDI: diphenylmethane-4,4'-diisocyanate.

[0077] Other particularly preferred monomeric polyisocyanate compounds are: diisocyanates such as 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- and 2,4,4-trimethyl-1,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3- and 1,4-diisocyanatocyclohexane, 1-polyisocyanato-3,3,5-trimethyl-5-polyisocyanatomethylcyclohexane (isophorone diisocyanate), 4,4'-diisocyanatodicyclohexylmethane, 2,4- and 2,6-diisocyanatomethylcyclohexane, and mixtures thereof. Aromatic polyisocyanates, e.g., toluene diisocyanates or 4,4'-diisocyanatodiphenylmetha, can also be used in principle.

[0078] 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, the isomers of toluene diisocyanate (TDI), optionally in a mixture, 1-methyl-2,4-diisocyanatocyclohexane, 1,6-diisocyanato-2,2,4-trimethylhexane, 1,6-diisocyanato-2,4,4-trimethylhexane, 1-isocyanatomethyl-3-isocyanato-1,5,5-trimethylcyclohexane, chlorinated and brominated Diisocyanates, phosphorus-containing diisocyanates, 4,4'-diisocyanatophenylperfluoroethane, tetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate (HDI), dicyclohexylmethane diisocyanate, cyclohexane-1,4-diisocyanate, ethylene diisocyanate, phthalic acid bisisocyanatoethyl ester, also polyisocyanates with reactive halogen atoms such as 1-chloromethylphenyl-2,4-Diisocyanate-1,2-Br 3,3-Bischloromethyl ether-4,4'-Diphenyl diisocyanate.

[0079] Surprisingly, it has been shown that the use of longer-chain aliphatic diisocyanates with six, seven, eight, nine, ten or even more carbon atoms leads to the formation of more stable capsule shells or capsule walls.

[0080] In a particularly preferred embodiment, the internal non-aqueous phase comprises a mixture of two or more different polymerizable polyisocyanates, for example polyisocyanates with different chain lengths, which can form copolymers.

[0081] Proportionally, derivatives of polyisocyanates, which can be produced by modifying the above-mentioned diisocyanates or their mixtures according to known methods and which contain, for example, uretdione, urethane, isocyanurate, biuret and / or allophane groups, can also be used in the process according to the invention.

[0082] Particularly preferred is a combination of at least two different, preferably aliphatic, polyisocyanates or a combination of at least one aliphatic and at least one aromatic polyisocyanate.

[0083] In such a combination, the different reaction rates of the polyisocyanates are exploited: Aromatic polyisocyanates react significantly faster than aliphatic polyisocyanates, and for short-chain aliphatic polyisocyanates, i.e., aliphatic polyisocyanates with one to five carbon atoms, preferably three to five carbon atoms, the reaction rate is higher compared to longer-chain analogues.

[0084] In a further preferred embodiment of the invention, the different aliphatic and / or aromatic polyisocyanates therefore also have different chain lengths. Longer-chain polyisocyanates preferably have six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, twenty-five, or more carbon atoms; more preferably, however, they have six to twelve carbon atoms, and particularly preferably six to eight carbon atoms. Shorter-chain polyisocyanates are understood to be polyisocyanates with one to five carbon atoms, and preferably polyisocyanates with three to five carbon atoms.

[0085] A preferred combination according to the invention is a short-chain aliphatic polyisocyanate (C1, C2, C3, C4, C5) and a long-chain aliphatic polyisocyanate (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more), or a combination of a short-chain aliphatic polyisocyanate (C1, C2, C3, C4, C5) with a long-chain aromatic polyisocyanate (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more), or a combination of a long-chain aliphatic polyisocyanate (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more) (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more) with a short-chain aromatic polyisocyanate.

[0086] Particularly preferred in this context is the use of a mixture of different aliphatic polyisocyanates with two or more isocyanate groups having chain lengths of one to twelve carbon atoms in the chain, preferably three to eight carbon atoms and particularly preferably four to seven carbon atoms, for the production of the biodegradable microcapsules according to the invention.

[0087] Aliphatic polyisocyanates are particularly preferable in this context due to their chemical similarity to bio-based systems. For example, both lysine and 1,5-diisocyanatopentane exhibit the same degradation product, 1,5-diaminopentane, and are therefore particularly suitable for use in the production of bio-based and biodegradable microcapsules, taking environmental considerations into account.

[0088] Primary embodiments comprise mixtures of longer-chain and shorter-chain diisocyanates in any desired mixing ratios. Preferably, the mixing ratio of longer-chain diisocyanates to shorter-chain diisocyanates is in the range of 4:1 to 1:4 and particularly preferably from 2:1 to 1:2.

[0089] Examples of preferred specific mixtures of at least one aliphatic polyisocyanate and at least one aromatic polyisocyanate are a mixture of a hexamethylene diisocyanate biuret with a trimethylol adduct of xylylene diisocyanate, a mixture of a hexamethylene diisocyanate biuret with a polyisocyanurate of diisocyanate, or a mixture of a hexamethylene diisocyanate biuret with a trimethylolpropane adduct of toluene diisocyanate.

[0090] Even more preferred is the combination of a short-chain aliphatic polyisocyanate and a long-chain aliphatic polyisocyanate described above, or the combination of a short-chain aliphatic polyisocyanate and a long-chain aromatic polyisocyanate, or the combination of a long-chain aliphatic polyisocyanate with a short-chain aromatic polyisocyanate, in which the polyisocyanates are present in a mixture of monomeric, oligomeric, or polymeric form.

[0091] Preferably, the following combinations result for use in the method according to the invention: short-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and short-chain aliphatic polyisocyanate (monomer or oligomer or polymer); short-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and long-chain aliphatic polyisocyanate (monomer or oligomer or polymer); short-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and short-chain aromatic polyisocyanate (monomer or oligomer or polymer); short-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and long-chain aromatic polyisocyanate (monomer or oligomer or polymer); long-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and short-chain aliphatic polyisocyanate (monomer or oligomer or polymer); long-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and long-chain aliphatic polyisocyanate (monomer or oligomer or polymer).polymer); long-chain aliphatic polyisocyanate (monomer or oligomer or polymer) and short-chain aromatic polyisocyanate (monomer or oligomer or polymer); long-chain aliphatic polyisocyanate (monomer) and long-chain aromatic polyisocyanate (oligomer or polymer); . with the previously described definitions for short-chain and long-chain.

[0092] It has been observed that the selection of at least two aliphatic polyisocyanates of different chain lengths and degrees of polymerization, or the selection of mixtures of aliphatic and aromatic polyisocyanates, leads to a significant gain in stability and performance (fragrance release in the case of fragrance capsules) due to the different reaction rates of the polyisocyanate components, dissociations, and crosslinking structures.

[0093] The aforementioned polyisocyanate combinations or polyisocyanate mixtures made from two different aliphatic or one aliphatic and one aromatic polyisocyanate allow for the creation of particularly stable and better, i.e., more densely branched, cross-links within the capsule shell.

[0094] The method described herein allows for the production of high-performance (fragrance-releasing) microcapsules, which are made either from a mixture of an aliphatic and an aromatic polyisocyanate or from a mixture of two different aliphatic polyisocyanates. Such microcapsules are very stable and exhibit outstanding fragrance retention properties, which in turn translates into improved performance (fragrance release) of the capsules, for example, in the field of fragrance or fragrance encapsulation.

[0095] The use of two different polyisocyanates results in microcapsules that exceed the stability of microcapsules made from single polyisocyanate systems, as illustrated in the following examples.

[0096] The microcapsule made from an aliphatic-aliphatic polyisocyanate mixture is just as effective as a microcapsule made from an aliphatic-aromatic polyisocyanate mixture, as illustrated in the following exemplary embodiments. Therefore, in principle, the combination of at least two different polymerizable (preferably aliphatic and / or aromatic) polyisocyanates is preferable in the present invention.

[0097] The polyisocyanate content for the production of the microcapsule according to the invention is 0.1 to 10.0 wt.%, preferably 0.5 to 3.0 wt.%, based on the total weight of the internal non-aqueous phase.

[0098] The proportion of the polyisocyanate component to the internal non-aqueous phase is preferably between 1:50 and 1:20, more preferably between 1:40 and 1:30.

[0099] Due to the low proportion of the polyisocyanate component, it is possible, according to the present disclosure, to produce polyurea / polyurethane microcapsules in which the absolute polyisocyanate content is only one-fifth of the total capsule, which comprises at least one lipophilic active ingredient to be encapsulated. Thus, using the process according to the invention, polyurea / polyurethane microcapsules can be produced that have a polyisocyanate content of only 0.6 wt%, based on the total weight of the capsule wall. Preferably, the polyisocyanate content is approximately 1.8 wt% of the capsule wall. Despite the low polyisocyanate content, the microcapsules according to the invention are nevertheless characterized by high stability.

[0100] In step (a1) of the process according to the invention for producing the microcapsules, the at least one polymerizable polyisocyanate, comprising at least two or more functional isocyanate groups, is first substantially dissolved together with at least one or more active ingredients to be encapsulated, optionally in an inert, non-aqueous solvent or a solvent mixture of inert, non-aqueous solvents. "Substantially dissolved" means that at least 90 wt.%, preferably at least 98 wt.%, and even more preferably 99.9 wt.%, of the aforementioned components are dissolved in the solvent or solvent mixture in order to be used in the present process. Preferably, the at least one polyisocyanate and the at least one active ingredient to be encapsulated are completely dissolved in the solvent or solvent mixture.If a solvent does not ensure sufficient solubility of the isocyanates, it is possible to overcome this disadvantage by using suitable solubility enhancers.

[0101] Preferred solvents for the internal non-aqueous phase are immiscible with water and do not react with the isocyanate component(s) or the active ingredient component(s) and have little or no odor in the amounts used.

[0102] The term "solvent" in connection with the present invention includes all types of oil bodies or oil components, in particular vegetable oils such as rapeseed oil, sunflower oil, soybean oil, olive oil and the like, modified vegetable oils, e.g. alkoxylated sunflower or soybean oil, synthetic (tri)glycerides such as 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), fatty acid alkyl esters based on these C6 to C22 fatty acids, mineral oils and mixtures thereof. Examples of suitable and preferred lipophilic solvents are: Guerbet alcohols based on fatty alcohols with 6 to 18, preferably 8 to 10, carbon atoms.Esters of linear C6 to C22 fatty acids with linear or branched C6 to C22 fatty alcohols or esters of branched C6 to C13 carboxylic acids with linear or branched C6 to C22 fatty alcohols, such as myristyl myristate, myristyl palmitate, myristyl stearate, myristyl isostearate, myristyl oleate, myristyl behenate, myristyl rucate, cetyl myristate, cetyl palmitate, cetyl stearate, cetyl isostearate, cetyl oleate, cetyl behenate, cetyl rucate, stearyl myristate, stearyl palmitate, stearyl stearate, stearyl isostearate, stearyl oleate, stearyl behenate, cetyl rucate, stearyl myristate, stearyl palmitate, stearyl stearate, stearyl isostearate, stearyl oleate, stearyl stearate, stearyl rucate, isostearyl myristate, isostearyl palmitate, isostearyl stearate Isostearyl isostearate, isostearate, isostearyl oleate, isostearyl behenate, oleyl myristate, oleyl palmitate, oleyl stearate, oleyl isostearate, oleyl oleate, oleyl behenate, oleyl oleucate, behenyl myristate, behenyl palmitate, behenyl stearate, behenyl isostearate, behenyl oleate, behenyl behenate, behenyl oleucate, erucyl myristate, erucyl palmitate, erucyl stearate, erucyl isostearate, erucyl oleate, erucyl behenate, and erucyl oleucate.

[0103] Also suitable are esters of linear C6 to C22 fatty acids with branched alcohols, in particular 2-ethylhexanol; esters of C18 to C38 alkylhydroxycarboxylic acids with linear or branched C6 to C22 fatty acids, in particular dioctylalate; esters of linear or branched fatty acids with polyhydric alcohols (such as propylene glycol, dimerdiol or trimertriol) and / or Guerbet alcohols; triglycerides based on C6 to C10 fatty acids; liquid mono- / di- / triglyceride mixtures of C6 to C18 fatty acids; esters of C6 to C22 fatty alcohols and / or Guerbet alcohols with aromatic carboxylic acids, in particular benzoic acid; esters of C2 to C12 dicarboxylic acids with linear or branched alcohols with 1 to 22 carbon atoms or polyols with 2 to 10 carbon atoms and 2 to 6 hydroxyl groups, vegetable oils, branched primary alcohols, substituted cyclohexanes, linear or branched C6 to C22 fatty alcohol carbonates,such as dicaprylyl carbonate (Cetiol®< CC); Guerbet carbonates based on fatty alcohols with 6 to 18, preferably 8 to 10 carbon atoms; benzoic acid esters with linear or branched C6 to C22 alcohols; linear or branched, symmetrical or asymmetrical dialkyl ethers with 6 to 22 carbon atoms per alkyl group, such as dicaprylyl ethers; ring-opening products of epoxidized fatty acid esters with polyols; silicone oils (cyclomethicones, silicone methicone grades, etc.); aliphatic or naphthenic hydrocarbons, such as squalane, squalene, or dialkylcyclohexanes; and / or mineral oils.

[0104] Preferred solvents include, in particular, esters of linear C6 to C22 fatty acids with branched alcohols, esters of C18 to C38 alkylhydroxycarboxylic acids with linear or branched C6 to C22 fatty alcohols, linear or branched C6 to C22 fatty alcohols, especially dioctyl malates, esters of linear or branched fatty acids with polyhydric alcohols, such as e.g.Propylene glycol, dimerdiol or trimertriol, and / or Guerbet 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 Guerbet alcohols with aromatic carboxylic acids, in particular benzoic acid, esters of C2 to C12 dicarboxylic acids with linear or branched alcohols with 1 to 22 carbon atoms or polyols with 2 to 10 carbon atoms and 2 to 6 hydroxyl groups, vegetable oils, branched primary alcohols, substituted cyclohexanes, linear and branched C6 to C22 fatty alcohol carbonates, such as dicaprylyl carbonate (Cetiol™ CC), Guerbet carbonates based on fatty alcohols with 6 to 18, preferably 8 to 10, carbon atoms, esters of benzoic acid with linear or branched C6 to C22 alcohols, linear or branched, symmetrical or asymmetrical dialkyl ethers with 6 to 22 carbon atoms per alkyl group, such as e.g.Dicaprylyl ethers (Cetiol TM OE), ring-opening products of epoxidized fatty acid esters with polyols, silicone oils (cyclomethicone, silicon methicone types, etc.) and / or aliphatic or naphthenic hydrocarbons, such as squalane, squalene or dialkylcyclohexanes.

[0105] Furthermore, liquid linear and / or branched and / or saturated or unsaturated hydrocarbons, or any desired mixtures thereof, can be used as solvents within the scope of the present invention. These can be, for example, alkanes with 4 to 22, preferably 6 to 18 carbon atoms, or any mixtures thereof.

[0106] Particularly suitable inert solvents for the internal non-aqueous phase include alkylaromatic hydrocarbons such as diisopropylnaphthalene or substituted biphenyls, chlorinated diphenyl, paraffins, 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 naphthalene, diaryl ethers, aryl alkyl ethers, and higher alkylated benzene, benzyl benzoate, isopropyl myristate, as well as any mixtures of these hydrophobic solvents and mixtures of one or more of these hydrophobic solvents with kerosene, paraffins, and / or isoparaffins. Vegetable oils such as sunflower oil, triglycerides, benzyl benzoate, or isopropyl myristate are preferably used as solvents for providing the internal non-aqueous phase.

[0107] The aforementioned solvents are used in the process according to the invention either individually or as a mixture of two or more solvents.

[0108] In an alternative and preferred embodiment of the process according to the invention, the at least one polyisocyanate is dissolved directly in a solution of the at least one active ingredient, preferably one or more fragrance or flavoring substances or a perfume oil, so that essentially no solvent, as described above, is present in the core of the microcapsule according to the invention. Avoiding a solvent in the microcapsule core is advantageous in order to reduce manufacturing costs and to consider environmental aspects.

[0109] The fragrance or flavoring substances are dissolved in solvents commonly used in the perfume or flavor industry. The solvent is preferably not an alcohol, as alcohols react with the isocyanates. Examples of suitable solvents include diethyl phthalate, isopropyl myristate, Abalyn® (rosin resins, available from Eastman), benzyl benzoate, ethyl citrate, limonene, or other terpenes or isoparaffins. Preferably, the solvent is highly hydrophobic. Preferably, the fragrance or flavoring solution contains less than 30% solvent. More preferably, the fragrance or flavoring solution comprises less than 20%, and even more preferably, less than 10% solvent, all these percentages defined by weight relative to the total weight of the fragrance or flavoring solution. Most preferably, the fragrance or flavoring is substantially solvent-free.

[0110] In principle, any material suitable for inclusion in microcapsules can be used as the active ingredient to be encapsulated or as the core material for the production of the microcapsules according to the invention. The active ingredients to be encapsulated are lipophilic, water-insoluble or water-immiscible liquids or solids, as well as suspensions. This ensures that the active ingredient to be encapsulated remains in the internal non-aqueous phase during the production of the microcapsule according to the invention and does not mix with the external aqueous phase, since otherwise no emulsion can form and no deposition of the capsule wall material on the droplet surface can occur. This results in the lipophilic active ingredient being completely enclosed inside the microcapsule as the core material during the subsequent emulsification and cross-linking of the capsule wall components.The resulting internal non-aqueous phase is characterized by its organically hydrophobic, oily nature.

[0111] In a particularly preferred embodiment of the present invention, the at least one lipophilic or hydrophobic active ingredient is, in particular, a lipophilic or hydrophobic fragrance or flavoring agent or a lipophilic or hydrophobic perfume oil or flavoring (fragrance or flavoring mixture), a cooling agent, a TRPV1 or a TRPV3 modulator, a substance that produces a sharp taste or a warmth or heat sensation on skin or mucous membranes or a tingling orcauses a tingling sensation in the mouth or throat, or is an active substance with a stinging, biting, or astringent effect, a pesticide, a biocide, an insecticide, a substance from the group of repellents, a food additive, a cosmetic active ingredient, a pharmaceutical active ingredient, a dye, a dye precursor, a fluorescent dye, an agrochemical, an optical brightener, a solvent, a wax, a silicone oil, a lubricant, a substance for printing coatings for paper, or a mixture of two or more of the aforementioned active substances.

[0112] In a preferred embodiment of the present invention, lipophilic active ingredients may in particular be lipophilic fragrances or fragrance mixtures consisting of two or more fragrances (perfume oils) or flavorings or flavoring mixtures consisting of two or more flavorings (flavors) or biogenic principles.

[0113] It is particularly preferred that the core comprises one or more fragrance or flavoring substances selected from the group consisting of: extracts of natural raw materials and fractions thereof or isolated components thereof; individual fragrance substances from a group of hydrocarbons; aliphatic alcohols; aliphatic aldehydes and acetals; aliphatic ketones and oximes; aliphatic sulfur-containing compounds; aliphatic nitriles; esters of aliphatic carboxylic acids; formates, acetates, propionates, isobutyrates, butyrates, isovalerates, pentanoates, hexanoates, crotonates, tiglinates and 3-methyl-2-butenoates of acyclic terpene alcohols; acyclic terpene aldehydes and ketones, as well as their dimethyl and diethyl acetals; Formates, acetates, propionates, isobutyrates, butyrates, isovalerates, pentanoates, hexanoates, crotonates, tiglinates and 3-methyl-2-butenoates of cyclic terpene alcohols; cyclic terpene aldehydes and ketones;cyclic alcohols; cyclic and cycloaliphatic ethers; cyclic and macrocyclic ketones; cycloaliphatic aldehydes; cycloaliphatic ketones; esters of cyclic alcohols; esters of cycloaliphatic alcohols; esters of cycloaliphatic carboxylic acids; aromatic hydrocarbons; araliphatic alcohols; esters of araliphatic alcohols and aliphatic carboxylic acids; araliphatic ethers; aromatic and araliphatic aldehydes; aromatic and araliphatic ketones; aromatic and araliphatic carboxylic acids and their esters; nitrogen-containing aromatic compounds; phenyl ethers and phenyl esters; heterocyclic compounds; lactones; and mixtures of the aforementioned active substances.

[0114] Suitable fragrances and flavorings for the production of the capsules according to the invention are preferably described, for example, in "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.

[0115] Preferably, the microcapsules according to the invention have a core material in the form of a hydrophobic single fragrance or single flavoring substance, wherein the core material comprises at least one single fragrance or single flavoring substance selected from one or more of the following groups: Hydrocarbons, such as 3-carene; alpha-pinene; beta-pinene; alpha-terpinene; gamma-terpinene; p-cymene; bisabolene; camphene; caryophyllene; cedrene; farnesene; limonene; longifolene; myrcene; ocimene; valencene; (E,Z)-1,3,5-undecatriene; styrene; diphenylmethane; aliphatic alcohols, such as hexanol; octanol; 3-octanol; 2,6-dimethylheptanol; 2-methylheptanol; 2-methyloctanol; (E)-2-hexenol; (E)- and (Z)-3-hexenol; 1-octen-3-ol; Mixture of 3,4,5,6,6-pentamethyl-3,4-hepten-2-ol and 3,5,6,6-tetramethyl-4-methyleneheptan-2-ol; (E,Z)-2,6-nonadienol; 3,7-dimethyl-7-methoxyoctan-2-ol; 9-decenol; 10-undecenol; 4-methyl-3-decen-5-ol; aliphatic aldehydes and their acetals, such as hexanal; heptanal; octanal; nonanal; decanal; undecanal; dodecanal; tridecanal; 2-methyloctanal; 2-methylnonanal; (E)-2-hexenal; (Z)-4-heptenal; 2,6-dimethyl-5-heptenal; 10-undecenal; (E)-4-Decenal; 2-dodecenal; 2,6,10-trimethyl-5,9-undecadienal; heptanal diethyl acetal;1,1-Dimethoxy-2,2,5-trimethyl-4-hexene; Citronellyloxyacetaldehyde; 1-(1-Methoxypropoxy)-(E / Z)-3-hexene; Aliphatic ketones and their oximes, such as 2-heptanone; 2-octanone; 3-octanone; 2-nonanone; 5-methyl-3-heptanone; 5-methyl-3-heptanone oxime; 2,4,4,7-tetramethyl-6-octen-3-one; 6-methyl-5-hepten-2-one; Aliphatic sulfur-containing compounds, such as 3-methylthiohexanol; 3-methylthiohexyl acetate; 3-mercaptohexanol; 3-mercaptohexyl acetate; 3-mercaptohexyl butyrate; 3-Acetylthiohexyl acetate; 1-Menthen-8-thiol; Aliphatic nitriles, such as 2-nonenonitrile; 2-tridecenitrile; 2,12-tridecenitrile; 3,7-Dimethyl-2,6-octadienonitrile; 3,7-Dimethyl-6-octenonitrile; Aliphatic carboxylic acids and their esters, such as (E)- and (Z)-3-hexenyl formate; Ethyl acetoacetate; Isoamyl acetate; Hexyl acetate; 3,5,5-Trimethylhexyl acetate; 3-Methyl-2-butenyl acetate; (E)-2-hexenyl acetate; (E)- and (Z)-3-hexenyl acetate; Octyl acetate; 3-Octyl acetate; 1-Octen-3-yl acetate;Ethylbutyrat; Butylbutyrat; Isoamylbutyrat; Hexylbutyrat; (E)- und (Z)-3-Hexenylisobutyrat; Hexylcrotonat; Ethylisovalerianat; Ethyl-2-methylpentanoat; Ethylhexanoat; Allylhexanoat; Ethylheptanoat; Allylheptanoat; Ethyloctanoat; Ethyl-(E,Z)-2,4-decadienoat; insbesondere Ethyl-2-trans-4-cis-decadienoat; Methyl-2-octinat; Methyl-2-noninat; Allyl-2-isoamyloxyacetat; Methyl-3,7-dimethyl-2,6-octadienoat; 4-Methyl-2-pentylcrotonat; Acyclische Terpenalkohole, wie beispielsweise Citronellol; Geraniol; Nerol; Linalool; Lavandulol; Nerolidol; Farnesol; Tetrahydrolinalool; Tetrahydrogeraniol; 2,6-Dimethyl-7-octen-2-ol; 2,6-Dimethyloctan-2-ol; 2-Methyl-6-methylen-7-octen-2-ol; 2,6-Dimethyl-5,7-octadien-2-ol; 2,6-Dimethyl-3,5-octadien-2-ol; 3,7-Dimethyl-4,6-octadien-3-ol; 3,7-Dimethyl-1,5,7-octatrien-3-ol; 2,6-Dimethyl-2,5,7-octatrien-I-ol; sowie deren Formiate, Acetate, Propionate, Isobutyrate, Butyrate, Isovalerianate, Pentanoate, Hexanoate, Crotonate, Tiglinate oder 3-Methyl-2-butenoate;Acyclic terpene aldehydes and ketones, such as geranial; neral; citronellal; 7-hydroxy-3,7-dimethyloctanal; 7-methoxy-3,7-dimethyloctanal; 2,6,10-trimethyl-9-undecenal; geranyl acetone; as well as the dimethyl and diethyl acetals of geranial, neral, and 7-hydroxy-3,7-dimethyloctanal; in particular the dimethyl and diethyl acetals of geranial, neral, and 7-hydroxy-3,7-dimethyloctanal; cyclic terpene alcohols, such as menthol; isopulegol; alpha-terpineol; terpinenol-4; menthan-8-ol; menthan-1-ol; menthan-7-ol; borneol; isoborneol; linalool oxide; nopol; cedrol; ambrinol; vetiverol; guajol; as well as their formates, acetates, propionates, isobutyrates, butyrates, isovalerates, pentanates, hexanoates, crotonates, tiglinates or 3-methyl-2-butenoates; cyclic terpene aldehydes and ketones, such as menthone; isomenthone; 8-mercaptomenthan-3-one; carvone; camphor; fenchone; alpha-ionone; beta-ionone; alpha-n-methylionone; beta-n-methylionone; alpha-isomethylionone; beta-isomethylionone;alpha-Iron; beta-Iron; alpha-Damascenon; beta-Damascenon; gamma-Damascenon; delta-Damascenon; gamma-Damascenon; 1-(2,4,4-Trimethyl-2-cyclohexen-1-yl)-2-buten-1-on; 1,3,4,6,7,8a-Hexahydro-1,1,5,5-tetramethyl-2H-2,4a-methanonaphthalen-8(5H)-on; 2-Methyl-4-(2,6,6-trimethyl-1-cyclohexen-1-yol)-2-butenal; Nootkaton; Dihydronootkaton; 4,6,8-Metgastigmatrien-3-on; alpha-Sinensal; beta-Sinensal; acetyliertes Cedernholzöl (Methylcedrylketon); Cyclische Alkohole, wie beispielsweise 4-tert-Butylcyclohexanol; 3,3,5-Trimethylcyclohexanol; 3-Isocamphylcyclohexanol; 2,6,9-Trimethyl-(Z2,Z5,E9)cyclododecatrien-1-ol; 2-Isobutyl-4-methyltetrahydro-2H-pyran-4-ol; aus der Gruppe der cycloaliphatischen Alkohole wie z. B. 3,3,3-Trimethylcyclohexylmethanol; 2-Methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)butanol; 2-Methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)-2-buten-1-ol; 2-Ethyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)-2-buten-1-ol; 3-Methyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-pentan-2-ol;3-Methyl-5-(2,2,3-trimethyl-3-cyclopent-1 -yl)-4-penten-2-ol; 3,3-Dimethyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol; 1-(2,2,6-Trimethylcyclohexyl)pentan-3-ol; 1-(2,2,6-Trimethylcyclohexyl)hexan-3-ol; Cyclische und cycloaliphatische Ether, wie beispielsweise Cineol; Cedrylmethylether; Cyclododecylmethylether; 1,1-Dimethoxycyclododecan; (Ethoxymethoxy)cyclododecan; alpha-Cedrenepoxid; 3a,6,6,9a-Tetramethyldodecahydronaphtho[2,1-b]furan; 3a-Ethyl-6,6,9a-trimethyl-dodecahydronaph-tho[2,1-b]furan; 1,5,9-Trimethyl-13-oxabicyclo[10.1.0]trideca-4,8-dien; Rosenoxid; 2-(2,4-Dimethyl-3-cyclohexen-1-yl)-5-methyl-5-(1-methylpropyl)-1,3-dioxan; Cyclische und macrocyclische Ketone, wie beispielsweise 4-tert-Butylcyclohexanon; 2,2,5-Trimethyl-5-pentylcyclopentanon; 2-Heptylcyclopentanon; 2-Pentylcyclopentanon; 2-Hydroxy-3-methyl-2-cyclopenten-1-on; 3-Methyl-cis-2-penten-1-yl-2-cyclopenten-1-on; 3-Methyl-2-pentyl-2-cyclopenten-1-on; 3-Methyl-4-cyclopentadecenon; 3-Methyl-5-cyclopentadecenon;3-Methylcyclopentadecanon; 4-(1-Ethoxyvinyl)-3,3,5,5-tetramethylcyclohexanon; 4-tert-Pentylcyclohexanon; 5-Cyclohexadecen-1-on; 6,7-Dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanon; 8-Cyclohexadecen-1-one; 7-cyclohexadecen-1-on; (7 / 8)-Cyclohexadecen-1-on; 9-Cycloheptadecen-1-on; Cyclopentadecanon; Cyclohexadecanon; Cycloaliphatische Aldehyde, wie beispielsweise 2,4-Dimethyl-3-cyclohexencarbaldehyd; 2-Methyl-4-(2,2,6-trimethyl-cyclohexen-1-yl)-2-butenal; 4-(4-Hydroxy-4-methylpentyl)-3-cyclohexencarbaldehyd; 4-(4-Methyl-3-penten-1-yl)-3-cyclohexencarbaldehyd; Cycloaliphatische Ketone, wie beispielsweise 1-(3,3-Dimethylcyclohexyl)-4-penten-1-on; 2,2-Dimethyl-1-(2,4-dimethyl-3-cyclohexen-1-yl)-1-1propanon; 1-(5,5-Dimethyl-2-cyclohexen-1-yl)-4-penten-1-on; 2,3,8,8-Tetramethyl-1,2,3,4,5,6,7,8-octahydro-2-naphtalenylmethylketon; Methyl-2,6,10-trimethyl-2,5,9-cyclododecatrienylketon; tert-Butyl-(2,4-dimethyl-3-cyclohexen-1-yl)keton;Esters of cyclic alcohols, such as 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; esters of cycloaliphatic alcohols, such as 1-cyclohexyl ethyl crotonate; esters of cycloaliphatic carboxylic acids, such as allyl-3-cyclohexyl propionate; allylcyclohexyl oxyacetate; cis- and trans-methyldihydrojasmonate; cis- and trans-methyljasmonate; 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; Aromatic hydrocarbons, such as styrene and diphenylmethane; Araliphatic alcohols, such as 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-phenylethyl 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; Esters of aliphatic alcohols and aliphatic carboxylic acids, such as benzyl acetate; benzyl propionate; benzyl isobutyrate; benzyl isovalerate; 2-phenylethyl acetate; 2-phenylethyl propionate; 2-phenylethyl isobutyrate; 2-phenylethyl isovalerate; 1-phenylethyl acetate; α-trichloromethylbenzyl acetate; α,α-dimethylphenylethyl acetate; α,α-dimethylphenylethyl butyrate; cinnamyl acetate; 2-phenoxyethyl isobutyrate;4-Methoxybenzylacetat; Araliphatische Ether, wie beispielsweise 2-Phenylethylmethylether; 2-Phenylethylisoamylether; 2-Phenylethyl-1-ethoxyethylether; Phenylacetaldehyddimethylacetal; Phenylacetaldehyd-diethylacetal; Hydratropaaldehyd-dimethylacetal; Phenylacetaldehyd-glycerinacetal; 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; Aromatische und araliphatische Aldehyde, wie beispielsweise Benzaldehyd; Phenylacetaldehyd; 3-Phenylpropanal; Hydratropaaldehyd; 4-Methylbenzaldehyd; 4-Methylphenylacetaldehyd; 3-(4-Ethylphenyl)-2,2-dimethylpropanal; 2-Methyl-3-(4-isopropylphenyl)-propanal; 2-Methyl-3-(4-tert-butylphenyl)propanal; 3-(4-tert-Butylphenyl)propanal; Zimtaldehyd; α-Butylzimtaldehyd; α-Amylzimtaldehyd; α-Hexylzimtaldehyd; 3-Methyl-5-phenylpentanal; 4-Methoxybenzaldehyd; 4-Hydroxy-3-methoxybenzaldehyd; 4-Hydroxy-3-ethoxybenzaldehyd; 3,4-Methylendioxybenzaldehyd; 3,4-Dimethoxybenzaldehyd;2-Methyl-3-(4-methoxyphenyl)propanal; 2-Methyl-3-(4-methylendioxyphenyl)propanal; ; Aromatic and araliphatic ketones, such as acetophenone; 4-methylacetophenone; 4-methoxyacetophenone; 4-tert-butyl-2,6-dimethylacetophenone; 4-phenyl-2-butanone; 4-(4-hydroxyphenyl)-2-butanone; 1-(2-naphthalenyl)ethanone; benzophenone; 1,1,2,3,3,6-hexamethyl-5-indanylmethylketone; 6-tert-butyl-1,1-dimethyl-4-indanylmethylketone; 1-[2,3-dihydro-1,1,2,6-tetramethyl-3-(1-methylethyl)-1H-5-indenyl]ethanone; 5',6',7',8'-Tetrahydro-3',5',5',6',8',8'-hexamethyl-2-acetonaphthone; Aromatic and araliphatic carboxylic acids and their esters, such as benzoic acid; phenylacetic acid; methyl benzoate; ethyl benzoate; hexyl benzoate; benzyl benzoate; methyl phenyl acetate; ethyl phenyl acetate; geranyl phenyl acetate; phenylethyl phenyl acetate; methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenylethyl cinnamate; cinnamyl cinnamate; allylphenoxyacetate; methyl salicylate; isoamyl salicylate; hexyl salicylate; cyclohexyl salicylate; cis-3-hexenyl salicylate; benzyl salicylate; phenylethyl salicylate;Methyl 2,4-dihydroxy-3,6-dimethyl benzoate; Ethyl 3-phenyl glycidate; Ethyl 3-methyl-3-phenyl glycidate; Nitrogen-containing aromatic compounds, such as 2,4,6-trinitro-1,3-dimethyl-5-tert-butylbenzene; 3,5-dinitro-2,6-dimethyl-4-tert-butylacetophenone; Cinnamic nitrile; 5-phenyl-3-methyl-2-pentenonitrile; 5-phenyl-3-methylpentanonitrile; Methyl anthranilate; Methyl-N-methyl anthranilate; Schiff bases of methyl anthranilate with 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; Phenols, phenyl ethers and phenyl esters, such as. B. Estragole; anethole; eugenol; eugenyl methyl ether; isougenol; isougenyl 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; from the group of heterocyclic compounds such as. B. 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; Lactones, such as B. 1,4-octanolide; 3-methyl-1,4-octanolide; 1,4-nonanolide; 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; ; as well as the stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers or epimers of the aforementioned substances; and mixtures of the aforementioned substances.

[0116] In a further variant of the inventive method, flavoring substances can also be encapsulated as core material in the form of a single flavoring, wherein the core material comprises at least one single flavoring substance or mixtures thereof as active ingredient.

[0117] Typical examples of flavorings or flavorings that can be encapsulated according to the invention are selected from the group consisting of: 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; carvone; camphene; caryophyllene; cineole; cinnamyl acetate; citral; citronellol; citronellal; citronellyl acetate; cyclohexyl acetate; cymene; damascone; decalactone; dihydrocoumarin; dimethyl anthranilate; dimethyl anthranilate; dodecalactone; ethoxyethyl acetate; ethyl butyric acid; ethyl butyrate; ethyl caprinate; ethyl capronate; ethyl crotonate; ethyl furaneol; ethyl guaiacol; ethyl isobutyrate; ethyl isovalerianate; ethyl lactate; ethyl methyl butyrate; ethyl propionate; eucalyptol; eugenol; ethylheptylate; 4-(p-Hydroxyphenyl)-2-butanone; gamma-decalactone; geraniol; geranyl acetate; geranyl acetate; grapefruit aldehyde; Methyl dihydrojasmonate (e.g. Hedione ®< );Heliotropin; 2-Heptanon; 3-Heptanon; 4-Heptanon; trans-2-Heptenal; cis-4-Heptenal; trans-2-Hexenal; cis-3-Hexenol; trans-2-Hexensäure; trans-3-Hexensäure; cis-2-Hexenylacetat; cis-3-Hexenylacetat; cis-3-Hexenylcapronat; trans-2-Hexenylcapronat; cis-3-Hexenylformiat; cis-2-Hexylacetat; cis-3-Hexylacetat; trans-2-Hexylacetat; cis-3-Hexylformiat; para-Hydroxybenzylaceton; Isoamylalkohol; Isoamylisovalerianat; Isobutylbutyrat; Isobutyraldehyd; Isoeugenolmethylether; Isopropylmethylthiazol; Laurinsäure; Leavulinsäure; Linalool; Linalooloxid; Linalylacetat; Menthol; Menthofuran; Methylanthranilat; Methylbutanol; Methylbuttersäure; 2-Methylbutylacetat; Methylcapronat; Methylcinnamat; 5-Methylfurfural; 3,2,2-Methylcyclopentenolon; 6,5,2-Methylheptenon; Methyldihydrojasmonat; Methyljasmonat; 2-Methylmethylbutyrat; 2-Methyl-2-Pentenolsäure; Methylthiobutyrat; 3,1-Methylthiohexanol; 3-Methylthiohexylacetat; Nerol; Nerylacetat; 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; Phellandrene; pentanedione; phenylethyl acetate; phenylethyl alcohol; phenylethyl alcohol; phenylethyl isovalerate; piperonal; propionaldehyde; propyl butyrate; Pulegone; Pulegol; sensory; sulfurol; terpinene; terpineol; terpinolene; 8,3-thiomenthanone; 4,4,2-thiomethylpentanone; thymol; delta-undecalactone; gamma-undecalactone; valences; 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-lactones (preferably gamma-undecalactone, gamma-nonalactone, gamma-decalactone);delta-Lactone (vorzugsweise 4-Methyldeltadecalacton, Massoilacton, Deltadecalacton, Tuberolacton); Methylsorbat; Divanillin; 4-Hydroxy-2(oder 5)-ethyl-5(oder 2)-methyl-3(2H)furanon; 2-Hydroxy-3-methyl-2-cyclopentenon; 3-Hydroxy-4,5-dimethyl-2(5H)-furanon; Essigsäureisoamylester; Buttersäureethylester; Buttersäure-n-butylester; Buttersäureisoamylester; 3-Methyl-buttersäureethylester; n-Hexansäureethylester; n-Hexansäureallylester; n-Hexansäure-n-butylester; n-Octansäureethylester; Ethyl-3-methyl-3-phenylglycidat; Ethyl-2-trans-4-cis-decadienoat; 4-(p-Hydroxyphenyl)-2-butanon; 1,1-Dimethoxy-2,2,5-trimethyl-4-hexan; 2,6-Dimethyl-5-hepten-1-al; Phenylacetaldehyd; 2-Methyl-3-(methylthio)furan; 2-Methyl-3-furanthiol; bis(2-Methyl-3-furyl)disulfid; Furfurylmercaptan; Methional; 2-Acetyl-2-thiazolin; 3-Mercapto-2-pentanon; 2,5-Dimethyl-3-furanthiol; 2,4,5-Trimethylthiazol; 2-Acetylthiazol; 2,4-Dimethyl-5-ethylthiazol; 2-Acetyl-1-pyrrolin; 2-Methyl-3-ethylpyrazin; 2-Ethyl-3,5-dimethylpyrazin;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; cinnamon alcohol; Methyl salicylate; isopulegol and the stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers or epimers of these substances not explicitly mentioned herein; and mixtures of the aforementioned substances.

[0118] Of the aforementioned individual fragrance substances that can be encapsulated in accordance with the present invention, fragrance substances having an aldehyde, carboxylic acid or ester functionality are preferably used.

[0119] Aldehyde fragrances, which also include the corresponding acetals, esters and lactones, can be divided into the following groups, namely (i) aliphatic aldehydes and their acetals; (ii) cycloaliphatic aldehydes; (iii) aromatic or araliphatic aldehydes; (iv) aliphatic, aromatic or araliphatic esters; and (v) lactones; as well as their respective mixtures.

[0120] The aforementioned fragrance substances with aldehyde, carboxylic acid or ester functionality, as well as mixtures thereof, are selected from one or more of the following groups: Aliphatic aldehydes and their acetals, such as 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 diethyl acetal; 1,1-dimethoxy-2,2,5-trimethyl-4-hexene; citronellyloxyacetaldehyde; cycloaliphatic aldehydes, such as 2,4-dimethyl-3-cyclohexenecarbaldehyde; 2-Methyl-4-(2,2,6-trimethyl-cyclohexen-1-yl)-2-butenal- 4-(4-Hydroxy-4-methylpentyl)-3-cyclohexenecarbaldehyde; 4-(4-Methyl-3-penten-1-yl)-3-cyclohexenecarbaldehyde; Aromatic and araliphatic aldehydes, such asBenzaldehyd; Phenylacetaldehyd; 3-Phenylpropanal; Hydratropaaldehyd; 4-Methylbenzaldehyd; 4-Methylphenylacetaldehyd; 3-(4-Ethylphenyl)-2,2-dimethylpropanal; 2-Methyl-3-(4-isopropylphenyl)- propanal; 2-Methyl-3-(4-te / t-butylphenyl)propanal; 3-(4-te / t-Butylphenyl)propanal; Zimtaldehyd; α-Butylzimtaldehyd; α-Amylzimtaldehyd; α-Hexylzimtaldehyd; 3-Methyl-5-phenylpentanal; 4-Methoxybenzaldehyd; 4-Hydroxy-3-methoxybenzaldehyd; 4-Hydroxy-3ethoxybenzaldehyd; 3,4-Methylendioxybenzaldehyd; 3,4-Dimethoxybenzaldehyd; 2-Methyl- 3-(4-methoxyphenyl)-propanal; 2-Methyl-3-(4-methylendioxyphenyl)-propanal; Aliphatische Carbonsäureester, wie z. B.(E)- und (Z)-3-Hexenylformiat; Ethylacetoacetat; Isoamylacetat; Hexylacetat; 3,5,5-Trimethylhexylacetat; 3-Methyl-2-butenylacetat; (f)-2-Hexenylacetat; (E)- und (Z)-3-Hexenylacetat; Octylacetat; 3-Octylacetat; 1-Octen-3-ylacetat; Ethylbutyrat; Butylbutyrat; Isoamylbutyrat; Hexylbutyrat; (E)- und (Z)-3- Hexenylisobutyrat; Hexylcrotonat; Ethylisovalerianat; Ethyl-2-methylpentanoat; Ethylhexanoat; Allylhexanoat; Ethylheptanoat; Allylheptanoat; Ethyloctanoat; Ethyl-(E,Z)-2,4-decadienoat; Methyl-2-octinat; Methyl-2-noninat; Allyl-2-isoamyloxyacetat; Methyl-3,7-dimethyl-2,6-octadienoat; Ester cyclischer Alkohole, wie z. B. 2-te / t-Butylcyclohexylacetat; 4-te / t-Butylcyclohexylacetat; 2-ieri-Pentylcyclohexylacetat; 4-te / t-Pentylcyclohexylacetat; Decahydro-2-naphthylacetat; 3-Pentyltetrahydro-2 / - / - pyran-4-ylacetat; Decahydro-2,5,5,8a-tetramethyl-2-naphthylacetat; 4,7-Methano-3a,4,5,6,7,7a-hexahydro-5- bzw. -6-indenylacetat; 4,7-Methano-3a,4,5,6,7,7a-hexahydro-5- bzw.-6-indenylpropionate; 4,7-Methano-3a,4,5,6,7,7a-hexahydro-5- or -6-indenyl isobutyrate; 4,7-Methanooctahydro-5- or -6-indenyl acetate; Esters of aliphatic alcohols and aliphatic carboxylic acids, such as benzyl acetate; benzyl propionate; benzyl isobutyrate; benzyl isovalerate; 2-phenylethyl acetate; 2-phenylethyl propionate; 2-phenylethyl isobutyrate; 2-phenylethyl isovalerate; 1-phenylethyl acetate; α-Trichloromethylbenzyl acetate; α,α-Dimethylphenylethyl acetate; α,α-Dimethylphenylethyl butyrate; Cinnamyl acetate; 2-Phenoxyethyl isobutyrate; 4-Methoxybenzyl acetate; Esters of cycloaliphatic carboxylic acids, such as allyl-3-cyclohexyl propionate; allylcyclohexyl oxyacetate; 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; aromatic and araliphatic carboxylic acid esters, such as...methyl benzoate; ethyl benzoate; hexyl benzoate; benzyl benzoate; methyl phenyl acetate; ethyl phenyl acetate; geranyl phenyl acetate; phenylethylphenylacetate; methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenylethyl cinnamate; cinnamyl cinnamate; allylphenoxyacetate; methyl salicylate; isoamyl salicylate; hexyl salicylate; cyclohexyl salicylate; cis-3-hexenyl salicylate; benzyl salicylate; phenylethyl salicylate; methyl 2,4-dihydroxy-3,6-dimethyl benzoate; ethyl 3-phenylglycidate; Ethyl 3-methyl-3-phenyl glycidate. .

[0121] The following are listed aldehydes, acetals, esters and lactones with their commercial names, which are particularly preferred as representatives of groups (i) to (v) in the sense of the process according to the invention:

[0122] Aldehyde: 2-Methylpentanal; Aldehyd C12 MNA HM; Aldehyde C 4; Aldehyde C 5; Aldehyde C 6; Aldehyde C 7; Aldehyde C 8; Aldehyde C 9; Aldehyde C 10; Aldehyde C 11 ISO; Aldehyde C 11 MOA PURE; Aldehyde C 11 UNDECANAL; Aldehyde C 11 UNDEYLENIC; Aldehyde C 12; ; Aldehyde C 12 MNA; Aldehyde C 13; ALDEHYDE MADARINE; AMYL CINNAMIC ALDEHYDE ALPHA; ANISALALDEHYDE-O; ANISYL ALDEHYDE; BENZALDEHYDE NAT.; BERGAMAL; BORONAL; BOURGENOAL; CAMPHONELIC ALDEHYDE; CITRAL; CITRONELLAL HM; CITRONELLYL OXYACET ALDEHYDE; CITRYLAL; CITROYLAL E HM; CORTEX ALDEHYDE; CORTEX ALDEHYDE 50 PCT PEMOSA; CROTONIC ALDEHYDE; CUMINAL ALDEHYDE; CYCLAMEN ALDEHYDE; DECADIENAL TRANS, TRANS-2,4, DECANAL CIS-4; DECANAL TRANS-2; DECANAL TRANS-2 NAT; DECANAL TRANS-4; DECANAL-9,1; DODECANIENAL 2,6; DODECANAL TRANS-2; DUPICAL; EPOXYDECENAL-4,5-2 10 % TRI; ETHYL HEXANAL; FARENAL ®< ; FLORHYDRAL; GERALDEHYDE; HELIONAL; HELIOPAN; HELIOTROPIN; HEPTADIENAL TRANS, TRANS,2-4; HEPTENAL CIS-4; HEPTENAL TRANS-2; HEXENAL TRANS-2; HEXYL CINNAMIC ALDEHYDE ALPHA; HYDRATROPIC ALDEHYDE; HYDROXY CITRONELLAL; INTRELEVEN ALDEHYDE SPEC.; ISONONYL ALDEHYDE; ISOVALERIC ALDEHYDE; LEMON ALDEHYDE H&R JS I; LILIAL; LINOLAL; LYRAL; MAJANTAL; MANDRINAL; MANDRAINE ALDEHYDE 10% IN TEC BHT; MEFRANAL; MELONAL ®< ; METHODY CITRONELLAL; METHYL BUTYRALDEHYDE; METHYL CINNAMIC ALDEHYDE ALPHA; METHYL PHENYLPENTENAL-4,2,2; METHYL THIO PROPANAL-3; METHYL TRIDECANAL-12 10 % VT; METHYL-3-BUTEN-2-AL; METHYL-5-PHENYL-2-HEXEN-2-AL; MUGENAL 50 DPG; NEOCYCLO CITRAL; NONADIENAL; TRANS, CIS-2,6; NONENAL CIS-6; NONENAL TRANS-2; ONCIDAL ®< 3 / 060251; PENTENAL TRANS-2; PERILLA ALDEHYDE; PHENYLACET ALDEHYDE; PHENYLBUTENAL TRANS-2,2; PHENYLPROPYL ALDEHYDE; PINOACET ALDEHYDE; PROFRANESAL; PROPIONALALDEHYD 2-(P-TOLYL); PROPIONIC ALDEHYDE; PS-IRALDEIN X NEU; SAFRANAL; SALICYLIC ALDEHYDE FG; SILVIAL; TETRAHYDRO CITRAL; TIGLIC ALDEHYDE-2,2; TOLYL ALDEHYDE PARA FG; TRIDECENAL TRANS-2; TRIFERNAL; UNDECADIENAL-2,4; UNDECENAL TRANS-2; VERNALALDEHYDE; VERTOCITRAL; VERTOMUGAL; VERTIPRENAL; VETRAL ROH; ZIMTALDEHYD NAT.HM; Acetale: FLOROPAL; HEPTANAL DIETHYL ACETAL; NONANDIENAL DIETHYL ACETAL; OKOUMAL; PHENYLACET ALD. GLYCERIN ACETAL; PHENYLACETALDEYHDEDIMETHYLACETAL; Ester: JASMAL; JESSEMAL; KHARISMAL; TIRAMISONE ®< .

[0123] In an alternative embodiment, the polyurea / polyurethane microcapsules according to the invention utilize a fragrance mixture, a perfume oil, a flavoring mixture, or a flavoring as the active ingredient to be encapsulated or as the core material. These are compositions containing at least one fragrance or flavoring. Such compositions, particularly fragrance mixtures or perfume oils, preferably comprise two, three, four, five, six, seven, eight, nine, ten, or even more fragrances. The fragrance mixtures or perfume oils are preferably selected from the group consisting of extracts of natural raw materials; essential oils, concretes, absolutes, resins, resinoids, balsams, tinctures, such as ambergris tincture; amyris oil; angelica seed oil; angelica root oil; anise oil; armoise oil; valerian oil; basil oil; tree moss absolutes; bay oil; mugwort oil; benzoin resin; bergamot oil; beeswax absolute; Birch tar oil; bitter almond oil;Savory oil; Buchco leaf oil; Cabreuva oil; Cadde oil; Calamus oil; Camphor oil; Cananga oil; Cardamom oil; Cascarilla oil; Cassia oil; Cassia absolute; Castoreum absolute; Cedar leaf oil; Cedarwood oil; Cistus oil; Citronellol oil; Lemon oil; Copaiba balsam; Copaiba balsam oil; Coriander oil; Costus root oil; Cumin oil; Cypress oil; Davana oil; Dill herb oil; Dill seed oil; Eau de brouts absolute; Oakmoss absolute; Elemi oil; Tarragon oil; Eucalyptus citriodora oil; Eucalyptus oil; Fennel oil; Spruce needle oil; Fir needle oil; Galbanum oil; Galbanum resin; Geranium oil; Grapefruit oil; Guaiac wood oil; Gurjun balsam; Gurjun balsam oil; Helichrysum absolute; Helichrysum oil; Ginger oil; Orris root absolute; Orris root oil; Jasmine absolute; Calamus oil; Blue chamomile oil; Roman chamomile oil; Carrot seed oil; Cascarilla oil; Pine needle oil; Spearmint oil; Caraway oil; Labdanum oil; Labdanum absolute; Labdanum resin; Lavandin absolute; Lavandin oil; Lavender absolute; Lavender oil; Lemongrass oil; Lovage oil; Distilled lime oil; Pressed lime oil; Linalool oil; Litsea cubeba oil;Bay laurel oil; bay leaf oil; mace oil; marjoram oil; mandarin oil; massoird oil; mimosa absolute; musk seed oil; musk tincture; clary sage oil; nutmeg oil; myrrh absolute; myrrh oil; myrtle oil; clove leaf oil; clove flower oil; neroli oil; frankincense absolute; frankincense 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; pepper oil; pimento oil; pine oil; poley oil; rose absolute; rosewood oil; rose oil; rosemary oil; Dalmatian sage oil; Spanish sage oil; sandalwood oil; celery seed oil; spike lavender oil; star anise oil; Styrax oil; marigold oil; fir needle oil; tea tree oil; turpentine oil; thyme oil; tolu balsam; tonka bean absolute; tuberose absolute; vanilla extract; violet leaf absolute; verbena oil; vetiver oil; juniper berry oil; wine yeast oil; wormwood oil; wintergreen oil; ylang-ylang oil; hyssop oil; civet absolute; cinnamon leaf oil; cinnamon bark oil; and fractions thereof or isolated components thereof.

[0124] Exemplary cooling agents used as lipophilic active ingredients in the manufacture of the microcapsules according to the invention include one or more of menthol and menthol derivatives (for example, L-menthol, D-menthol, racemic menthol, isomenthol, neoisomenthol, neomenthol), menthyl ethers (for example, (1-menthoxy)-2-propanediol, (1-menthoxy)-2-methyl-1,2-propanediol, 1-menthyl methyl ether), menthyl esters (for example, menthyl formate, menthyl acetate, menthyl isobutyrate, menthyl lactate, L-menthyl L-lactate, L-menthyl D-lactate, menthyl (2-methoxy) acetate, menthyl (2-methoxyethoxy) acetate, menthyl pyroglutamate), menthyl carbonates (for example, menthyl propylene glycol carbonate, Menthylethylene glycol carbonate, menthylglycerol carbonate or mixtures thereof), the semiesters of menthol with a dicarboxylic acid or their derivatives (for example, monomenthyl succinate, monomenthyl glutarate, monomenthyl malonate, O-menthyl succinate-N,N-(dimethyl) amide, O-menthyl succinamide),Menthane carboxamides (for example, menthane carboxylic acid N-ethylamide [WS3], N-alpha-(methanecarbonyl)glycine ethyl ester [WS5], menthane carboxylic acid N-(4-cyanophenyl)amide, menthane carboxylic acid N-(alkoxyalkyl)amide), menthone and menthone derivatives (for example, L-menthone glycerol ketal), 2,3-dimethyl-2-(2-propyl)butanoic acid derivatives (for example, 2,3-dimethyl-2-(2-propyl)butanoic acid N-methylamide [WS23]), isopulegol or its esters (1-(-)-isopulegol, 1-(-)-isopulegol acetate), menthane derivatives (for example, p-menthane-3,8-diol), cubebol or synthetic or natural mixtures containing cubebol, pyrrolidone derivatives of cycloalkyldione derivatives (for example, 3-Methyl)-2-(1-Pyrrolidinyl)-2-cyclopenten-1-one) or tetrahydropyrimidin-2-one (for example, icilin or related compounds, as described in WO 2004 / 026840). Other cooling agents include menthol (L-menthol, D-menthol, racemic menthol, isomenthol, neoisomenthol, neomenthol), L-menthyl methyl ether, menthyl formate, menthyl acetate).Menthone, isopulegol, L-(-)-isopulegol acetate) and cubebol, which have a cooling flavor effect. Suitable cooling agents are well known in the field 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).

[0125] In an alternative embodiment, the polyurea / polyurethane microcapsules according to the invention utilize a TRPV1 or TRPV3 modulator as the active ingredient to be encapsulated or as the core material. TRPV1 and TRPV3 modulators are known in the art and relate to transient receptor potential (TRP) channels of the vanilloid (TRPV) subfamily. TRPV1 modulators mediate a pungent taste and the hot sensation associated with capsaicin and piperine. The TRPV3 protein belongs to the family of non-selective cation channels that function in a variety of processes, including temperature sensation and vasoregulation. The TRPV3 channel is directly activated by various natural compounds such as carvacrol, thymol, and eugenol. Some other monoterpenoids, which either induce a sensation of warmth or act as skin sensitizers, can also open the channel.Monoterpenoids also induce agonist-specific desensitization of TRPV3 channels in a calcium-independent manner.

[0126] In a further variant, the active ingredient to be encapsulated or the core material in the polyurea / polyurethane microcapsules according to the invention is selected from the group consisting of substances that cause a sharp taste or a sensation of warmth or heat on skin or mucous membranes or a tingling or prickling sensation in the mouth or throat, or active ingredients with a stinging, biting or astringent effect.

[0127] The heat-inducing or pungent active ingredients are selected from the group consisting of: paprika powder, chili pepper powder, extracts of paprika, extracts of pepper, extracts of chili pepper, extracts of ginger root, extracts of grains of paradise (Aframomum melegueta), extracts of paracress (Jambu-oleoresin; Spilanthes acmella), respectively.Spilanthes oleracea, extracts of Japanese pepper (Zanthoxylum piperitum), extracts of Kaempferia galanga, extracts of Alpinia galanga, extracts of water pepper (Polygonium hydropiper), capsaicinoids, in particular capsaicin, dihydrocapsaicin or nonivamide; gingerols, in particular gingerol-[6], gingerol-[8], or gingerol-

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

[10] ; gingerdiones, in particular gingerdione-[6], gingerdione-[8] or gingerdione-

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

[10] ; Dehydrogingerdiones, in particular dehydrogingerdione-[6], dehydrogingerdione-[8] or dehydrogingerdione-

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

[0128] The active ingredients, which are perceived as stinging or biting, are selected from the group consisting of: aromatic isothiocyanates, in particular phenylethyl isothiocyanate, allyl isothiocyanate, cyclopropyl isothiocyanate, butyl isothiocyanate, 3-methylthiopropyl isothiocyanate, 4-hydroxybenzyl isothiocyanate, 4-methoxybenzyl isothiocyanate and their mixtures.

[0129] The tingling-inducing active ingredients are selected from the group consisting of 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 described in WO 2004 / 000787; 2Z,4Z-decadienoic acid N-isobutylamide; 2Z,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-decadienoic acid N-(2-methylbutyl)amide; 2E,4E-decadienoic acid-N-piperide (achilleamide); 2E,4E-decadienoic acid-N-piperide (Sarmentin); 2E-decenoic acid-N-isobutylamide; 3E-decenoic acid-N-isobutylamide; 3E-nonenoic acid N-isobutylamide; 2E,6Z,8E-decatrienoic acid-N-isobutylamide spilanthol; 2E,6Z,8E-decatrienoic acid-N-([2S]-2-methylbutyl)amide homospilanthol; 2E,6Z,8E-decatrienoic acid N-([2R]-2-methylbutyl)amide; 2E-Decen-4-ynoic acid-N-isobutylamide;2Z-Decen-4-insäure-N-isobutylamid; 2E,6Z,8E, 10E-Dodecatetraensäure-N-(2-methylpropyl)amid alpha-Sanshool; 2E,6Z,8E,10E-Dodecatetraensäure-N-(2-hydroxy-2-methylpropyl)amid alpha-Hydroxysanshool; 2E,6E,8E,10E-Dodecatetraensäure-N-(2-hydroxy- 2-methylpropyl)amid gamma-Hydroxysanshool; 2E,4E,8Z,10E, 12E-Tetradecapentaensäure-N-(2-hydroxy-2-methylpropyl)amid gamma-Hydroxysanshool; 2E,4E,8E,10E,12E-Tetradecapentaensäure-N-(2-hydroxy-2-methylpropyl)-amid gamma-Hydroxyisosanshool; 2E,4E,8Z, 10E,12E-Tetradecapentaensäure-N-(2-methyl-2-propenyl)amid gamma-Dehydrosanshool; 2E,4E,8Z,10E,12E-Tetradecapentaensäure-N-(2-methylpropyl)amid gamma-Sanshool; 2E,4E,8Z,11Z-Tetradecatetraensäure-N-(2-hydroxy-2-methylpropyl)amid Bungeanool; 2E,4E,8Z,11E-Tetradecatetraensäure-N-(2-hydroxy-2-methylpropyl)amid Isobungeanool; 2E,4E,8Z-Tetradecatriensäure-N-(2-hydroxy-2-methylpropyl)amid Dihydrobungeanool und 2E,4E-Tetradecadiensäure-N-(2-hydroxy-2-methylpropyl)amid Tetrahydrobungeanool und deren Gemische.;

[0130] Active ingredients with astringent properties are selected from the group consisting of: catechins, in particular epicatechins, gallocatechins, epigallocatechins and their respective gallic acid esters, in particular epigallocatechin gallate or epicatechin gallate, their oligomeric procyanidins, proanthocyanidins, prodelphinidins, procyanirins, thearubigenins, theogallins 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 quercetrin, rutin, gallic acid esters of carbohydrates such as tannin, pentagalloylglucose or their reaction products such as elligatannin, aluminum salts, e.g. alum, and their mixtures.

[0131] In a further variant of the inventive method, biogenic principles can also be encapsulated as core material, wherein the core material comprises at least one biogenic principle or mixtures thereof.

[0132] Biogenic principles refer to active substances with biological activity, such as tocopherol, tocopherol acetate, tocopherol palmitate, ascorbic acid, carnotin, carnosine, caffeine, (deoxy)ribonucleic acid and their fragmentation products, β-glucans, retinol, bisabolol, allantoin, phytantriol, panthenol, AHA acids, amino acids, ceramides, pseudoceramides, essential oils, plant extracts, and vitamin complexes.

[0133] In another variant of the inventive method, substances for printing coatings for paper are also used as the active ingredient to be encapsulated or as the core material, as described in US 2800457A.

[0134] The content of lipophilic active ingredient or lipophilic active ingredient mixture for the production of the microcapsule according to the invention is 90.0 to 99.9 wt.%, preferably 97.0 to 99.5 wt.%, based on the total weight of the internal non-aqueous phase.

[0135] The ratio of one or more active ingredient components to the internal non-aqueous phase is preferably between 50 : 1 and 20 : 1, more preferably between 40 : 1 and 30 : 1.

[0136] Thus, it is possible to achieve a high loading of the microcapsules according to the invention with active ingredient using the method according to the invention.

[0137] Furthermore, the first polymerization and / or crosslinking step (a) of the process according to the invention includes the provision of an external aqueous phase comprising at least a protective colloid and optionally an emulsifier (a2).

[0138] For this purpose, the protective colloid and, optionally, the emulsifier are dissolved in the external aqueous phase, preferably an aqueous solvent. Suitable solvents are water or mixtures of water with at least one water-miscible organic solvent. Suitable organic solvents include, for example, glycerin, 1,2-propanediol, 1,3-propanediol, ethanediol, diethylene glycol, triethylene glycol, and other analogues. Preferably, however, the solvent is water.

[0139] A protective colloid is a polymer system that prevents clumping (agglomeration, coagulation, flocculation) of emulsified, suspended, or dispersed components in suspension or dispersion. During solvation, protective colloids bind large amounts of water and, depending on the concentration, generate high viscosities in aqueous solutions. In the production of oil-in-water emulsions, the protective colloid attaches its hydrophobic portion to the primary particles and orients its polar, i.e., hydrophilic, molecular portion toward the aqueous phase. This attachment at the interface reduces the interfacial tension and prevents agglomeration of the primary particles. Furthermore, it stabilizes the emulsion and promotes the formation of comparatively smaller droplets and thus also of corresponding microcapsules.

[0140] In the process according to the invention, the protective colloid exhibits emulsifying properties in addition to the aforementioned properties. With sufficient emulsifying properties of the protective colloid, such as carboxymethylcellulose, acid-modified starch, polyvinyl alcohol, ammonium derivatives of polyvinyl alcohol, polystyrene sulfonates, polyvinylpyrrolidones, or polyvinyl acrylates, the process according to the invention can advantageously even dispense with the use of an emulsifier in the subsequent emulsifying or dispersing step.

[0141] The protective colloid used in the inventive method is selected from the group consisting of Diols, in particular ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, isomeric butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-dodecanediol, and polyols, preferably triols, in particular glycerol and its ethoxylation and propoxylation products, trimethylolpropane and its ethoxylation and propoxylation products, polyvinyl alcohol (PVOH) and its derivatives, in particular ammonium- or sulfonate-functionalized polyvinyl alcohols, polyphenols, preferably 1,3,5-trihydroxybenzene, polysaccharides, in particular glucose, starches or chemically, mechanically and / or enzymatically modified starches, cellulose derivatives such as hydroxyethylcellulose, in particular quaternized hydroxyethylcellulose, and carboxymethylcellulose, Polyvinylpyrrolidone, maleic acid vinyl copolymers, sodium lignosulfonates, maleic anhydride / styrene copolymers, ethylene / maleic anhydride copolymers, ethylene oxide copolymers,Propylene oxide and acid esters of polyethoxylated sorbitol, sodium dodecyl sulfate, animal and plant polymers, proteins, gelatin, frankincense resin, shellac, lignin, chitosan, saponin as well as mixtures of the aforementioned compounds.

[0142] Preferably, the external aqueous phase comprises at least one protective colloid selected from polyvinylpyrrolidones, polyvinyl alcohols, and mixtures thereof. Polyvinylpyrrolidones are particularly preferred. Commercial standard polyvinylpyrrolidones have molar masses in the range of approximately 2,500 to 750,000 g / mol. For the production of the microcapsules according to the invention, polyvinyl alcohol or its ammonium derivatives, 1,3,5-trihydroxybenzene, or starches, in particular modified starches, or animal or plant polymers are particularly preferred as the protective colloid.

[0143] Starches, especially modified starches, or animal or plant polymers are naturally occurring substances that are biodegradable. In combination with the polyisocyanates described herein, the present process can therefore be used to produce bio-based and biodegradable capsule shells. In the process according to the invention, the starch and the animal and plant polymers also function as so-called bio-crosslinkers.

[0144] The starch used in the process according to the invention is selected from the group consisting of maize starch, potato starch, rye starch, wheat starch, barley starch, oat starch, rice starch, pea starch, tapioca starch and mixtures thereof.

[0145] The chemically modified starches are preferably acid-modified starches, alkali-modified starches, oxidized starches, acetylated starches, succinate starches or octenylsuccinate starches.

[0146] According to the present invention, combinations of two or more different protective colloids can also be used to produce the microcapsule according to the invention.

[0147] In the process according to the invention, it has proven particularly advantageous to use a combination of one of the aforementioned protective colloids with starch as a further protective colloid in the external aqueous phase. Due to the high number of functional hydroxyl groups, such a combination stabilizes the emulsion and, secondly, promotes a reaction between the protective colloid and the polyisocyanate(s), shifting the reaction equilibrium in the reaction of the protective colloids with the polyisocyanate(s) towards the products, i.e., the polyurethanes. Furthermore, the large number of functional hydroxyl groups in starch enables the formation of particularly pronounced spatial cross-links.

[0148] Depending on the number of functional groups and / or the size of the protective colloid, the aforementioned protective colloids exhibit different reaction rates with the isocyanate groups of the at least one polyisocyanate. For example, glycerol reacts faster with the isocyanate groups than starch due to its size. Therefore, the crosslinking of the protective colloid with the isocyanate groups of the polyisocyanate can be controlled by selecting the appropriate protective colloid.

[0149] Glycerin with starch or with modified starch, or the combination of glycerin with quaternized hydroxyethylcellulose or gum arabic type Seyal, has proven to be particularly advantageous; with such a combination, one takes advantage of the previously described properties of both protective colloids: the high reaction rate of glycerin on the one hand and the number of polymerizable functional groups of the other protective colloid on the other.

[0150] The protective colloids used in the inventive method have a dual function: firstly, they act as a protective colloid and thus prevent the agglomeration of the emulsified, suspended or dispersed components, secondly, they stabilize the subsequently formed emulsion, thirdly, they promote the formation of small droplets and thirdly, they stabilize the ultimately formed microcapsule dispersion.

[0151] Secondly, the protective colloid cross-links with the at least one or more polyisocyanates due to its polymerizable properties, for example, functional groups, especially OH groups, undergoing polymerization. This cross-linking with the at least one polyisocyanate forms a polymer layer during the emulsification step (a3), which contributes to the formation of the capsule wall and becomes part of it.

[0152] Surprisingly, it was found that during the emulsification or suspension of the internal non-aqueous phase in the external aqueous phase, in the presence of the protective colloid, preferably a polyol, polymerization and / or cross-linking occurs near the core at the interfaces of the emulsified or suspended hydrophobic active ingredient oil droplets to be encapsulated, which form the core of the microcapsule according to the invention, and the outer external phase. This polymerization and / or cross-linking is based on the polyaddition reaction of the polyisocyanate with the protective colloid, preferably a polyol, forming a capsule shell or capsule wall made of polyurethane according to the following formula: n O=C=NR 1< -N=C=O + n HO-R 2< -OH- & (-R 2< -O-CO-NH-R 1< -NH-CO-O-) n

[0153] This is evident through gas evolution and the release of carbon dioxide.

[0154] By forming a polymer layer during the emulsification or dispersing step, the active ingredient(s) to be encapsulated, especially those with aldehyde, carboxylic acid or ester functionalities, are protected, thus preventing or at least minimizing deprotonation, oxidation or saponification, particularly in the subsequent process step, and thereby reducing or eliminating the loss of liphophilic active ingredient(s); such degradation products also typically contribute to the instability of the emulsion.

[0155] According to the present invention, the ratio of the amount of protective colloid or protective colloids used to the aqueous phase is preferably in a range of 1:50 to 1:10, more preferably in a range of 1:40 to 1:30.

[0156] The ratio of protective colloid in the external aqueous phase to polyisocyanate in the internal non-aqueous phase is in a range of 1:5 to 1:2, preferably in a range of 1:2 to 1:1.

[0157] The amount of protective colloid used, or the amount of a combination of protective colloids used, is therefore in the range of 1 to 8 wt.%, preferably in the range of 2 to 4 wt.%, even more preferably in the range of 3 to 4 wt.%, based on the total weight of the external aqueous phase.

[0158] The at least one protective colloid can, but does not have to, be a component of the capsule shell. In particular, protective colloids with a higher reactivity, as described above, will react more quickly or easily with the isocyanate groups of the polyisocyanate component and thus form polyurethane crosslinking units that are part of the capsule shell or capsule wall, in amounts of 0.1 to a maximum of 15 wt.%, but preferably in the range of 1 to 5 wt.% and even more preferably from 1.5 to 3 wt.%, based on the weight of the capsules.

[0159] To facilitate the formation of an emulsion or dispersion from the internal non-aqueous phase and the external aqueous phase, to stabilize the formed emulsion or dispersion, and to prevent separation of the internal non-aqueous (oily / organic / hydrophobic) phase and the external aqueous (hydrophilic) phase, an emulsifier or emulsifying agent is optionally added to the external aqueous phase in the process according to the invention. The addition of an emulsifier is optional when the protective colloid has no or only weak, i.e., insufficient, emulsifying properties. If an emulsifying protective colloid is used, the use of an emulsifier can advantageously be omitted in the process according to the invention.

[0160] In the process according to the invention, preferably oil-in-water (O / W) emulsifiers are used, which enable a homogeneous distribution of the oil droplets of the internal non-aqueous phase in the external aqueous phase and stabilize the emulsion. A similar principle applies to the mixing of solid, insoluble active ingredients in the external aqueous phase in order to stabilize the dispersion thus obtained.

[0161] Suitable emulsifiers include, for example, nonionic surfactants from at least one of the following groups: Addition products of 2 to 30 mol of ethylene oxide and / or 0 to 5 mol of propylene oxide to linear fatty alcohols with 8 to 22 carbon atoms, to fatty acids with 12 to 22 carbon atoms, to alkylphenols with 8 to 15 carbon atoms in the alkyl group, and to alkylamines with 8 to 22 carbon atoms in the alkyl group; alkyl and / or alkenyl oligoglycosides with 8 to 22 carbon atoms in the alk(en)yl group and their ethoxylated analogues; addition products of 1 to 15 mol of ethylene oxide to castor oil and / or hydrogenated castor oil; addition products of 15 to 60 mol of ethylene oxide to castor oil and / or hydrogenated castor oil; Partial esters of glycerol and / or sorbitan with unsaturated, linear or saturated, branched fatty acids with 12 to 22 carbon atoms and / or hydroxycarboxylic acids with 3 to 18 carbon atoms and their adducts with 1 to 30 mol of ethylene oxide;Partial esters of polyglycerol (average degree of condensation 2 to 8), polyethylene glycol (molecular weight 400 to 5000), trimethylolpropane, pentaerythritol, sugar alcohols (e.g., sorbitol), alkyl glucosides (e.g., methyl glucoside, butyl glucoside, lauryl glucoside), and polyglucosides (e.g., cellulose) with saturated and / or unsaturated, linear or branched fatty acids with 12 to 22 carbon atoms and / or hydroxycarboxylic acids with 3 to 18 carbon atoms, as well as their adducts with 1 to 30 mol of ethylene oxide, preferably Cremophor®; mixed esters of pentaerythritol, fatty acids, citric acid, and fatty alcohol, and / or mixed esters of fatty acids with 6 to 22 carbon atoms, methyl glucose, and polyols, preferably glycerol or polyglycerol; Mono-, di- and trialkyl phosphates as well as mono-, di- and / or tri-PEGalkyl phosphates and their salts; wool wax alcohols; polysiloxane-polyalkyl-polyether copolymers or corresponding derivatives;Block copolymers, e.g., polyethylene glycol-30 dipolyhydroxystearate; polymer emulsifiers, e.g., Pemulen types (TR-1, TR-2) from Goodrich or Cosmedia® SP from Cognis; polyalkylene glycols and glycerol carbonate.

[0162] Typical anionic emulsifiers that can be used in the inventive process for the production of isocyanate-based microcapsules are aliphatic fatty acids with 12 to 22 carbon atoms, such as palmitic acid, stearic acid or behenic acid, and dicarboxylic acids with 12 to 22 carbon atoms, such as azelaic acid or sebacic acid.

[0163] Furthermore, zwitterionic surfactants can be used as emulsifiers in the inventive process for producing the isocyanate-based microcapsules. Zwitterionic surfactants are defined as surface-active compounds that contain at least one quaternary ammonium group and at least one carboxylate and one sulfonate group in their molecule. Particularly suitable zwitterionic surfactants are the so-called betaines, such as the N-alkyl-N,N-dimethylammonium glycinates, for example cocoalkyldimethylammonium glycinate, N-acylaminopropyl-N,N-dimethylammonium glycinates, for example cocoacylaminopropyldimethylammonium glycinate, and 2-alkyl-3-carboxylmethyl-3-hydroxyethylimidazolines, each with 8 to 18 carbon atoms in the alkyl or acyl group, as well as cocoacylaminoethylhydroxyethylcarboxymethylglycinate. The fatty acid amide derivative known under the CTFA name cocamidopropyl betaine is particularly preferred.

[0164] Ampholytic surfactants are also suitable emulsifiers. Ampholytic surfactants are defined as surface-active compounds that, in addition to an 8 / 18 alkyl or acyl group in the molecule, contain at least one free amino group and at least one -COOH or -SO3H group and are capable of forming internal salts. Examples of suitable ampholytic surfactants include N-alkylglycines, N-alkylpropionic acids, N-alkylaminobutyric acids, N-alkyliminodipropionic acids, N-hydroxyethyl-N-alkylamidopropylglycines, N-alkyltaurines, N-alkylsarcosines, 2-alkylaminopropionic acids, and alkylaminoacetic acids, each with approximately 8 to 18 carbon atoms in the alkyl group. Particularly preferred ampholytic surfactants are N-cocosalkylaminopropionate, cocosacylaminoethylaminopropionate, and C12 / 18-acylsarcosine.

[0165] Finally, cationic surfactants can also be considered as emulsifiers, with those of the ester quat type being particularly preferred, preferably methylquaternated difatty acid triethanolamine ester salts, quaternized hydroxyethylcellulose, modified chitosan with propylene glycol and quaternized with epichlorohydrin, distearyldimethylammonium chloride (DSDMAC), benzalkonium chloride, benzethonium chloride, cetylalkonium chloride, cetylpyridinium chloride, cetyltrimethylammonium bromide (cetrimonium bromide), and dequalinium chloride.

[0166] The emulsifiers can be added to the external aqueous phase in an amount of about 0.5 to about 10 wt.% and preferably about 1 to about 5 wt.%, in each case based on the total weight of the external aqueous phase.

[0167] The aqueous protective colloid-emulsifier solution is preferably prepared under stirring by adding the protective colloid and optionally the emulsifier to the external aqueous phase successively, or vice versa, or by adding the protective colloid and optionally the emulsifier to the external aqueous phase simultaneously.

[0168] It may be advantageous if, for the production of the polyurea / polyurethane microcapsules according to the present invention, the external aqueous phase optionally contains stabilizers either dissolved or dispersed in order to prevent separation of the internal non-aqueous (oily) phase and the external aqueous phase.

[0169] The preferred stabilizers for the production of the isocyanate-based microcapsules according to the present invention are primarily acrylic copolymers possessing sulfonate groups. Copolymers of acrylamides and acrylic acid, copolymers of alkyl acrylates 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, microcrystalline cellulose, which is commercially available, for example, under the name VIVAPUR®, diutan gum, xanthan gum or carboxymethylcelluloses are also suitable.

[0170] The amount of stabilizers used can range from 0.01 to 10 wt.% and in particular from 0.1 to 3 wt.%, in each case based on the external aqueous phase.

[0171] Before mixing the internal non-aqueous phase and the external aqueous phase, or before emulsifying / dispersing the internal non-aqueous phase in the external aqueous phase, the pH of the external aqueous phase is adjusted to an acidic pH in the range of 1 to 5. Preferably, the pH of the external aqueous phase is adjusted to a pH in the range of 3 to 5.

[0172] The pH of the external aqueous phase is adjusted by adding an organic acid. Formic acid or acetic acid are most commonly used for pH adjustment.

[0173] The oil-in-water emulsion is produced by mixing the internal non-aqueous phase and the external aqueous phase. The weight ratio of the internal non-aqueous phase to the external aqueous phase is preferably in the range of 2:1 to 1:10, and more preferably in the range of 1:2 to 1:4.

[0174] Emulsion formation with liquid active ingredients and dispersion formation with solid active ingredients—that is, the emulsification or dispersion of the internal non-aqueous or oily phase in the external aqueous or hydrophilic phase—occurs under high turbulence or strong shear. The diameter of the resulting microcapsules can be precisely controlled by the intensity of the turbulence or shear. The droplet size can be verified by light scattering measurements or microscopy. Microcapsule production can be continuous or batchwise. As the viscosity of the aqueous phase increases or the viscosity of the oily phase decreases, the size of the resulting capsules generally decreases.

[0175] The inventive method for producing the polyurea / polyurethane microcapsules can be carried out, for example, using a forced metering pump according to the "inline" technique, or in conventional dispersion apparatus or emulsifying devices under stirring.

[0176] The emulsification or dispersion of the internal non-aqueous phase in the external aqueous phase for the production of microcapsules according to the invention was carried out using an emulsifying turbine (IKA Eurostar 20 high-speed stirrer). The emulsification process in step (a3) ​​of the method according to the invention is advantageously carried out 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.

[0177] After completion of the emulsification or dispersing step (a3), an oil-in-water emulsion or dispersion is present, in which the internal oily phase containing the active ingredients to be encapsulated is finely emulsified or dispersed in the external aqueous phase in the form of droplets.

[0178] In a subsequent step (a4) of the process according to the invention, a first polymerization and / or cross-linking of the capsule shell or capsule wall material is also carried out under stirring conditions. The first cross-linking is effected by adding at least one amino acid or at least one amino acid hydrochloride, preferably in the form of an aqueous solution, in the presence of a catalyst. The addition of the amino acid or the amino acid hydrochloride and the catalyst preferably takes place at a temperature of 20 to 30 °C.

[0179] The first amino acid, at least one, is selected from the group consisting of arginine, histidine, lysine, tryptophan, ornithine, and mixtures thereof.

[0180] It is often advantageous to use the amino acid as a hydrochloride. The hydrochlorides of the aforementioned amino acids are more readily soluble in water and therefore more readily soluble in the external aqueous phase. Furthermore, using the amino acid as a hydrochloride shifts the pH of the reaction mixture towards the acidic range, which, in addition to improved solubility, also leads to increased reactivity between the at least one polyisocyanate and the first amino acid, and thus to enhanced polymerization and / or cross-linking between these two components.

[0181] The at least one amino acid hydrochloride is selected from the group consisting of arginine hydrochloride, histidine hydrochloride, lysine hydrochloride, tryptophan hydrochloride, ornithine hydrochloride and mixtures thereof.

[0182] The amino acids arginine, lysine, and ornithine, or their corresponding amino acid hydrochlorides, are compounds with 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 chain. The aforementioned amino acids and their hydrochlorides thus exhibit multifunctionality for polymerization with at least one polyisocyanate.

[0183] Due to the cross-linking between the functional groups of the at least one polyisocyanate and the at least one amino acid or the amino acid hydrochloride, first cross-linking units or a first cross-linking matrix are formed, which become part of the capsule shell or the capsule wall.

[0184] Of the aforementioned amino acids, the basic amino acid arginine or its hydrochloride analogue is particularly preferred as a crosslinking agent because of its water solubility, its high reactivity and its pH value both as an amino acid and as a hydrochloride.

[0185] The use of amino acids or amino acid hydrochlorides as crosslinking agents is particularly advantageous from an environmental perspective with regard to biodegradability and biocompatibility.

[0186] The amino acid or amino acid hydrochloride, i.e., the first crosslinking agent, is added to the emulsion or dispersion either as such, 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.

[0187] The amount of the at least one amino acid or the at least one amino acid hydrochloride is adjusted so that for each mole of isocyanate group, 1 to 3 moles of amino groups, preferably 1 to 2 moles of amino groups, are added.

[0188] No specific action is required to induce polymerization between the at least one polyisocyanate or the multiple polyisocyanates and the first amino acid or the amino acid hydrochloride. The reaction begins immediately after the addition of the amino acid or the amino acid hydrochloride to the oil-in-water emulsion or dispersion, forming initial crosslinking units or a first crosslinking matrix. Because the reaction between the at least one polyisocyanate or the multiple polyisocyanates and the first amino acid or the amino acid hydrochloride is sufficiently rapid, it does not require a catalyst.

[0189] To optimize the polymerization or crosslinking between the functional groups of the at least one polyisocyanate or several polyisocyanates and the first amino acid or the amino acid hydrochloride, the pH of the emulsion or dispersion is adjusted to a pH in the range of 4 to 8 at the beginning of the reaction. Preferably, the pH of the emulsion or dispersion is adjusted to a pH in the range of 6 to 8.

[0190] The pH of the emulsion or dispersion is adjusted by adding an aqueous alkaline solution. Sodium hydroxide or potassium hydroxide are most commonly used for pH adjustment.

[0191] The formation of the first crosslinking units in the process according to the invention is based on the polyaddition reaction of the polyisocyanate or polyisocyanates with the amino acid or the amino acid hydrochloride. The first crosslinking units, which form the capsule shell or capsule wall, are based on a polyurea structure. The formation of the polyurea linkage or polyurea structure occurs through polyaddition of the amino group(s) (-NH₂) of the at least one amino acid or the at least one amino acid hydrochloride to the isocyanate group of the at least one polyisocyanate: n O=C=NR₁< -N=C=O + n H₂ NR₂< - & (-O-NH₂R₁< -NH₂CO-NH₂R₂< -) n

[0192] In the process according to the invention, a first crosslinking matrix or first crosslinking units, in particular polyurea crosslinking units, for the construction of a capsule shell or capsule wall are formed by interfacial polymerization at the interface of the emulsified or dispersed oil droplets that enclose the lipophilic active ingredient to be encapsulated.

[0193] Through the formation of the first crosslinking matrix or crosslinking units, the emulsified or dispersed oil droplets with the core material, i.e. the encapsulated active ingredients, are enclosed at the interface by the crosslinking matrix or the crosslinking units on the outside, thus generating a capsule wall, which makes diffusion of the encapsulated active ingredient more difficult.

[0194] The addition of at least one first catalyst to the emulsion or dispersion accelerates the reaction between polyisocyanates and the amino acid or amino acid hydrochloride and catalyzes the reaction in favor of the formation of a polyurea crosslinking matrix.

[0195] The catalyst added in the process according to the invention is preferably diazabicyclo[2.2.2]octane (DABCO), also known as triethylenediamine (TEDA), a bicyclic tertiary amine. DABCO is generally used as a catalyst for the production of polyurethane plastics. The tertiary amine with lone pairs of electrons promotes the reaction between the at least one polymerizable polyisocyanate and the amino groups of the first amino acid or the amino acid hydrochloride.

[0196] In addition to DABCO, catalysts based on bismuth or tin are also used for the catalysis of the first crosslinking, such as catalysts based on bismuth(II) salts or bismuth(III) salts, as described in KC Frisch & LP Rumao, Catalysis in Isocyanate Reactions, Polymer Reviews, 1970, 5:1, pages 103 - 149, DOI: 10.1080 / 1 5583727008085365.

[0197] Diazabicyclo[2.2.2]octane (DABCO) is particularly preferred as a catalyst.

[0198] A combination of DABCO and one of the aforementioned catalysts is preferred according to the invention. Such a mixture leads to a multiplication of the reactivity, as described in KC Frisch & LP Rumao, Catalysis in Isocyanate Reactions, Polymer Reviews, 1970, 5:1, pages 103-149, DOI: 10.1080 / 15583727008085365.

[0199] In the process according to the invention, DABCO and the aforementioned catalysts preferably catalyze the polyurethane reaction between the at least one polymerizable polyisocyanate with two or more isocyanate groups and the diols or polyols.

[0200] The amount of catalyst added to the emulsion or dispersion is in the range of 0.01 to 1 wt%, and preferably in the range of 0.05 to 0.2 wt%, based on the total weight of the emulsion or suspension. In the case of a slow polymerization reaction, the required amount of catalyst can be adjusted accordingly.

[0201] The ratio of catalyst in the emulsion or dispersion to the at least one polyisocyanate in the internal non-aqueous phase is preferably in a range of 1:20 to 1:50.

[0202] It has proven advantageous to first disperse or dissolve the catalyst in water and then add it to the emulsion or dispersion while stirring.

[0203] The addition of the first amino acid or the amino acid hydrochloride and the catalyst is preferably carried out at a stirring speed of 500 rpm to 2000 rpm, particularly preferably at 1000 rpm to 1500 rpm and at temperatures of 20 °C to 30 °C, preferably at temperatures of 22 °C to 26 °C.

[0204] The first polymerization and / or crosslinking in the process according to the invention is carried out for a period of about 10 minutes to 20 minutes, preferably for a period of 12 to 18 minutes and most preferably for a period of about 15 minutes.

[0205] Surprisingly, adding the catalyst after the emulsification or dispersing step led to a significant increase in capsule stability. Capsules produced in this way exhibit considerably higher stability, even after 10 days at 50 °C, and a significant reduction in free perfume oil compared to capsules produced without the addition of a catalyst.

[0206] Particularly stable capsules could be produced using the catalyst diazabicyclo[2.2.2]octane (DABCO).

[0207] The first polymerization and / or crosslinking step (a) in the process according to the invention is followed by a further, i.e. 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 process step (a4) in order to further build up the capsule shell or capsule wall.

[0208] The at least one hydroxyl group donor is preferably a polyol having two or more functional hydroxyl groups with good to very good water solubility at temperatures above 40 °C.

[0209] The hydroxyl group donor is selected from the group consisting of glycerol, propylene glycol, 1,3,5-trihydroxybenzene, starches, modified starches, cellulose derivatives such as hydroxyethylcellulose, in particular quaternized hydroxyethylcellulose, or carboxymethylcellulose, and mixtures thereof. Glycerol and starch are preferred; glycerol is most preferred.

[0210] The starch used in the process according to the invention is selected from the group consisting of maize starch, potato starch, rye starch, wheat starch, barley starch, oat starch, rice starch, pea starch, tapioca starch and mixtures thereof.

[0211] The modified starches are preferably chemically modified starches, namely acid-modified starches, alkali-modified starches, oxidized starches, acetylated starches, succinate starches or octenylsuccinate starches.

[0212] According to the present invention, a combination of two different hydroxyl group donors can also be used to produce the microcapsule according to the invention.

[0213] Depending on their size, the aforementioned hydroxyl group donors exhibit different reaction rates with the isocyanate groups of the at least one polyisocyanate. For example, glycerol reacts faster with the isocyanate groups than starch due to its size.

[0214] Glycerol with starch or modified starch, or the combination of glycerol with quaternized hydroxyethylcellulose or gum arabic type Seyal, has proven to be particularly advantageous; with such combinations, one takes advantage of the properties of both hydroxyl group donors described above: high reaction rate of glycerol on the one hand and number of polymerizable functional groups of starch on the other.

[0215] Through the reaction of at least one polyisocyanate and / or isothiocyanate with the hydroxyl groups of the hydroxyl group donor, a further, i.e., second, crosslinking matrix or second crosslinking units are formed for the construction or formation of the capsule shell or capsule wall, the structure of which can be derived analogously to the polyurethane crosslinking units from polyisocyanates and protective colloid, as described above.

[0216] The polyaddition reaction of the at least one polyisocyanate with the hydroxyl group donor results in the formation of so-called urethane bridges (-NH-CO-C-) by addition of the hydroxyl groups of the hydroxyl group donor (-OH) to the carbon atom of the carbon-nitrogen bond of the polyisocyanate groups (-N=C=O).

[0217] The formation of such additional polyurethane crosslinking units further crosslinks and densifies the first polyurea crosslinking units formed in the first polymerization and / or crosslinking step (a4).

[0218] To obtain particularly efficient, dense and stable cross-links, the second polymerization and / or cross-linking step (b) with the hydroxyl group donor is carried out at temperatures between 40 °C and 60 °C, and preferably at temperatures between 45 °C and 55 °C, and even more preferably at temperatures between 45 °C and 50 °C.

[0219] Furthermore, it is preferred that the step of further crosslinking by adding the hydroxyl group donor is carried out at stirring speeds of 900 rpm to 1700 rpm, preferably from 1000 rpm to 1300 rpm.

[0220] In this context, it has been found that adding the hydroxyl group donor in aqueous form leads to particularly stable cross-links and therefore particularly stable capsule shells or capsule walls. The concentration of the hydroxyl group donor in the aqueous solution is preferably 10% to 70%, and even more preferably 40% to 60%.

[0221] The second polymerization and / or crosslinking step (b) in the process according to the invention is followed by a further, i.e., third, polymerization and / or crosslinking step (c). In this third crosslinking step, at least one further, i.e., a second, amino acid is added as a crosslinking agent to the oil-in-water emulsion obtained in crosslinking step (b).

[0222] The at least one second amino acid is selected from the group consisting of arginine, histidine, aspartic acid, lysine, glycine, alanine, proline, cysteine, glutamine, leucine, serine, tryptophan, valine, threonine, ornithine, uric acid, and mixtures thereof.

[0223] The aforementioned amino acids are compounds with at least one amino group in the side chain and therefore possess functionality for polymerization and / or crosslinking with the at least one polyisocyanate.

[0224] Of the aforementioned amino acids, the basic amino acids such as arginine, histidine, lysine or their hydrochloride analogues are particularly preferred because of their high reactivity and their pH values ​​both as amino acids and as hydrochlorides.

[0225] In the process according to the invention, arginine is particularly preferred as a crosslinking agent because of its water solubility.

[0226] The use of amino acids or amino acid hydrochlorides as crosslinking agents is particularly advantageous from an environmental perspective with regard to biodegradability and biocompatibility.

[0227] The second amino acid or amino acid hydrochloride is added to the emulsion either as such, 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.

[0228] The amount of the at least one second amino acid or the amino acid hydrochloride is typically adjusted so that for each mole of isocyanate group, 1 to 3 moles of amino groups, preferably 1 to 2 moles of amino groups, are added.

[0229] To optimize the polymerization or crosslinking between the functional groups of the at least one polyisocyanate or several polyisocyanates and the second amino acid or the amino acid hydrochloride, the pH of the emulsion or dispersion is adjusted to a pH in the range of 4 to 8 at the beginning of the reaction. Preferably, the pH of the emulsion or dispersion is adjusted to a pH in the range of 6 to 8.

[0230] The pH of the emulsion or dispersion is adjusted by adding an aqueous alkaline solution. Sodium hydroxide or potassium hydroxide are most preferably used for pH adjustment.

[0231] By adding a second amino acid in the presence of the catalyst described above, a third crosslinking matrix or third crosslinking units are formed in the process according to the invention for the construction of the capsule shell or capsule wall. These third crosslinking units are based on the polyaddition reaction of individual polymers or oligomers of the polyisocyanate or polyisocyanates with the amino acid to form a capsule shell or capsule wall based on a polyurea structure. The formation of the polyurea linkage or polyurea structure occurs through polyaddition of the amino group(s) (-NH₂) of the at least one amino acid to the isocyanate group of the at least one polyisocyanate: n O=C=NR₁< -N=C=O + n H₂ NR₂< - + & (-O-NH₂R₁< -NH₂CO-NH₂R₂< -) n

[0232] The formation of such additional polyurea crosslinking units further crosslinks and densifies the polyurea and polyurethane crosslinking units formed in the first and second polymerization and / or crosslinking steps (a4) and (b).

[0233] The addition of the second amino acid or the amino acid hydrochloride is preferably carried out at a stirring speed of 500 rpm to 2000 rpm, particularly preferably at 1000 rpm to 1500 rpm and at a temperature of 60 to 80 °C, preferably 60 °C.

[0234] The third crosslinking step in the inventive method is carried out for a duration of about 10 to 20 minutes, preferably for a duration of 12 to 18 minutes and most preferably for a duration of about 15 minutes.

[0235] In order to obtain a particularly efficient, dense and stable network from the capsule wall components, a further, i.e. second, catalyst can optionally be added to the emulsion or dispersion in a further step (d).

[0236] The further catalyst added in the process according to the invention is preferably para-toluenesulfonic acid, sulfuric acid, germanium oxide, or enzymatic catalysts, preferably Candida antarctica lipase B (CALB). These catalysts are preferably catalysts that promote esterification reactions.

[0237] The addition of a further catalyst to the emulsion or dispersion preferably accelerates ester reactions, i.e., the formation of polyesters, from cross-linking of protective colloid, hydroxyl group donor and separating agent, and further catalyzes the reaction in favor of the formation of a three-dimensional, dense and stable polyurea and / or polyurethane and / or polyester cross-linking matrix.

[0238] The amount of catalyst added to the emulsion or dispersion is in the range of 0.01 to 1 wt%, and preferably in the range of 0.05 to 0.2 wt%, based on the total weight of the emulsion or dispersion. In the case of a slow polymerization reaction, the required amount of catalyst can be adjusted accordingly.

[0239] The ratio of catalyst in the emulsion or dispersion to the at least one polyisocyanate in the internal non-aqueous phase is preferably in a range of 1:20 to 1:50.

[0240] It has proven advantageous to first disperse or dissolve the catalyst in water and then add it to the emulsion or dispersion while stirring.

[0241] The addition of the further catalyst preferably takes place at a stirring speed of 500 rpm to 2000 rpm, particularly preferably at 1000 rpm to 1500 rpm, and at temperatures of 20 °C to 30 °C, preferably at temperatures of 22 °C to 26 °C. The crosslinking promoted or accelerated by the further catalyst in the process according to the invention is carried out for a period of about 10 minutes to 20 minutes, preferably for a period of 12 to 18 minutes, and most preferably for a period of about 15 minutes.

[0242] By combining a first polymerization or crosslinking step between polyisocyanate and a first amino acid, a second polymerization or crosslinking step between polyisocyanate and a hydroxyl group donor, and a third polymerization or crosslinking step between polyisocyanate and a second amino acid, polyurea and polyurethane crosslinking units or crosslinking matrices can be generated that form the capsule shell or capsule wall. In the process according to the invention, the first, second, and third polyurea and polyurethane crosslinking units are further spatially crosslinked with each other and with each other by the sequential crosslinking steps. The optional combination with a further catalyst allows, in addition to the above-mentioned...Polyurea and polyurethane crosslinking units also generate polyester crosslinks, which in turn lead to further crosslinking and thus to the formation of a three-dimensional, dense and stable capsule shell or capsule wall of the microcapsule.

[0243] The higher the number of cross-linking functional groups, the greater the spatial cross-linking and the denser and more stable the resulting capsule shell or capsule wall of the microcapsule. Besides the number of functional groups, the chain length of the individual building blocks significantly influences the mechanical properties, i.e., the stability, of the capsules. For example, the large number of hydroxyl groups in starch enables the formation of particularly pronounced spatial cross-links. Longer-chain capsule shell or capsule wall building blocks, such as polyisocyanates, lead to the formation of more stable capsule shells or capsule walls.

[0244] During the crosslinking steps described above, the stirring power is reduced, preferably to a stirring speed of about 800 to 1200 rpm, in order not to immediately break up the crosslinking units forming the capsule shell.

[0245] After the third polymerization or crosslinking step and the complete crosslinking and formation of the capsule shell or capsule wall, the capsules produced according to the inventive method are present as crude microcapsules in the form of an aqueous dispersion or a slurry.

[0246] After crosslinking, the microcapsules in the slurry still have a flexible shell that lacks significant stability and therefore ruptures easily. To address this, the microcapsule shell is hardened. Hardening is preferably achieved by gradually raising the temperature of the microcapsule dispersion to at least 60 °C, preferably to a temperature in the range of 60 to 65 °C, up to a maximum of the microcapsule dispersion's boiling point. The hardening process is typically carried out for at least 60 minutes, preferably 2 to 4 hours.

[0247] It is additionally advantageous to add substances for hardening to the external aqueous phase. For this purpose, natural plant tannins of the tannin type are used, which are chemically proanthocyanidins found in dicotyledonous herbaceous plants, shrubs, and leaves, particularly in the tropics and subtropics. The terpenes typically have molecular weights in the range of 500 to 3000 kDa. A preferred example of a suitable tannin is corigallin. For hardening, an aqueous preparation of the tannins is added to the aqueous dispersion containing the crude microcapsules. The tannins are usually added in amounts of about 0.1 to about 2 wt% and preferably about 0.5 to about 1.5 wt%, based on the microcapsules.

[0248] After the curing step (e) of the process according to the invention, at least one release agent is added to the microcapsule dispersion or microcapsule slurry in a further process step (f), which adheres to the microcapsule shell or microcapsule wall or preferably is deposited in the microcapsule shell or microcapsule wall.

[0249] The separating agent is conventionally a liquid or paste-like substance that prevents adhesion between two materials. In the case of the present invention, the substances are those that are embedded in the microcapsule shell or microcapsule wall and form ionic or even covalent bonds with the existing cross-linking structures of the capsule material via functional groups, for example OH groups or COOH groups.

[0250] The at least one separating agent used in the process according to the invention is selected from the group consisting of fatty acids, fatty alcohols, fatty acid esters and animal and vegetable waxes.

[0251] Fatty acids are aliphatic monocarbonates with mostly unbranched carbon chains. They differ in the number of carbon atoms (chain length) and—in the case of unsaturated fatty acids—in the number and position of double bonds. Based on their chain lengths, fatty acids can be classified as short-chain (up to 6 to 8 carbon atoms), medium-chain (8 to 12 carbon atoms), and long-chain (13 to 21 carbon atoms).

[0252] Fatty alcohols are aliphatic, long-chain, monohydric, mostly primary alcohols. The hydrocarbon residues in native fatty alcohols are often unbranched, while synthetic fatty alcohols are frequently branched. The carbon chain contains 6 to 30 carbon atoms and can be monounsaturated or polyunsaturated. Fatty alcohols are found in natural waxes, bound as carboxylic acid esters, e.g., in wool wax or spermaceti, and are often called wax alcohols.

[0253] Wax is an organic compound that melts at temperatures above approximately 40 °C, forming a low-viscosity liquid. Waxes can vary considerably in their chemical composition and origin. The main components of these mixtures are esters of fatty acids with long-chain, aliphatic primary alcohols, known as fatty alcohols. These esters differ structurally from fats and fatty oils, which are triglycerides of fatty acids. Furthermore, these waxes also contain free, long-chain, aliphatic carboxylic acids, ketones, alcohols, and hydrocarbons. Waxes can be of animal or plant origin.

[0254] The at least one separating agent in the inventive method is preferably selected from the group consisting of: long-chain, aliphatic, linear or branched, saturated or unsaturated carboxylic acids with 12 to 30 carbon atoms (fatty acids), in particular lauric acid (12:0), tridecanoic acid (13:0), myristic acid (14:0), pentadecanoic acid (15:0), palmitic acid (16:0), margaric acid (17:0), stearic acid (18:0), nonadecanoic acid (19:0), arachidic acid (20:0), heneicosanoic acid (21:0), behenic acid (22:0), lignoceric acid (24:0), cerotic acid (26:0), montanic acid (28:0) and melissic acid (30:0);Myristoleic acid (14:1), Palmitoleic acid (16:1), Margaroleic acid (17:1), Petroselic acid (18:1), Oleic acid (18:1), Elaidic acid (18:1), Vaccenic acid (18:1), Gadoleic acid (20:1), Gondoic acid (20:1), Cetoleic 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), Calendic acid (18:3), Punicic 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), Docosatetraenoic acid (ADA) (22:4), docosapentaenoic acid (DPA-3) (22:5), docosahexaenoic acid (22:6) and tetracosahexaenoic acid (24:6); phytanic acid;long-chain, aliphatic, linear or branched, saturated or unsaturated primary alcohols with 12 to 30 carbon atoms (fatty alcohols), 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 melissyl alcohol (30:0); palmitoleyl alcohol (16:1), oleyl alcohol (18:1), elaedyl alcohol (18:1), linoleyl alcohol (18:2), gamma-linolenyl alcohol (18:3); Esters of long-chain, aliphatic saturated carboxylic acids with 12 to 30 C atoms with long-chain, aliphatic primary alcohols with 12 to 30 C atoms, especially lauryl palmitate, myricyl palmitate, cetylarachinate and stearyl behenate;animal and plant waxes, in particular wool wax, Chinese wax, beeswax, sunflower seed wax, rice bran wax, carnauba wax, pinova wax, rapeseed wax, soy wax, candelilla wax, jojoba oil, cork wax, guaruma wax, cottonseed wax, flaxseed wax, peat wax, rose wax, jasmine wax, Peetha wax from the gourd, and myrtle wax; (Myrica cerifera), Wax fig wax, berry wax, as well as mixtures of two or more of the aforementioned separating agents.

[0255] Of the carboxylic acids listed above, the saturated fatty acids are preferred. The use of the animal and vegetable waxes specified above is most preferred in the process according to the invention due to their lower melting points, which facilitate incorporation into the microcapsule shell or microcapsule wall.

[0256] The at least one release agent has a dual function: Its incorporation into the microcapsule shell or microcapsule wall and the formation of ionic or covalent bonds with the crosslinking units or crosslinking matrices result, firstly, in further stabilization of the microcapsule shell. Secondly, the incorporation of the release agent into the microcapsule shell or microcapsule wall creates predetermined breaking points for the biodegradability of the microcapsule shell; that is, points in the microcapsule wall designed to prioritize the degradation of the microcapsule material. This facilitates the biodegradability of the microcapsule shell or microcapsule wall. Furthermore, the use of a release agent that stabilizes the microcapsule shell or microcapsule wall allows for a reduction in other capsule wall materials that are less biodegradable or not biodegradable at all.

[0257] The release agent is added to the microcapsule dispersion or microcapsule slurry in an amount of 1 to 10% by weight, based on the capsule shell. Preferably, the release agent is added in an amount of 2 to 5% by weight, based on the capsule shell.

[0258] The at least one release agent is added to the microcapsule dispersion or microcapsule slurry from process step (e) at a temperature of at least 60 °C up to a maximum of the boiling point of the microcapsule dispersion, preferably at a temperature of 80 °C. At this temperature, the release agent is in a liquid or molten form, so that it can be easily melted into and incorporated into the existing cross-linked structures of the microcapsule shell.

[0259] After the addition of the at least one release agent, a post-curing step is carried out on the polyurea / polyurethane microcapsules obtained in step (g), preferably at a temperature of at least 60 °C to 100 °C for a period of 60 to 240 minutes.

[0260] After hardening, the microcapsules produced according to the inventive process exist as a dispersion in water, also known as microcapsule dispersion or microcapsule slurry. In this form, the microcapsules are generally ready for sale.

[0261] To prevent separation or creaming of such a suspension and thus achieve high storage stability, it has proven advantageous for the suspension to have a viscosity of 12 to 1500 mPas. A thickening agent is preferably used to obtain the desired viscosity of the suspension.

[0262] The thickening agents preferably used are xanthan gum, diuthan gum, carboxymethylcellulose (CMC), microcrystalline cellulose (MCC) or guar gum.

[0263] To improve shelf life, one or more preservatives are optionally added to the microcapsule slurry, or the microcapsule slurry is dried.

[0264] Preferably, 1,2-hexanediol, 1,2-octanediol or parmetol are used as preservatives.

[0265] Alternatively, the microcapsules are separated and dried for preservation purposes.

[0266] In principle, processes such as lyophilization are suitable, but spray drying, for example in a fluidized bed, is preferred. It has proven advantageous to add further polysaccharides, preferably dextrins and especially maltodextrins, to the dispersion at temperatures of approximately 20 to approximately 50 °C and preferably approximately 40 °C. These polysaccharides support the drying process and protect the capsules during this process. The amount of polysaccharides used can be approximately 50 to approximately 150 wt% and preferably approximately 80 to approximately 120 wt%, based on the capsule mass, in the dispersion.

[0267] The spray drying process itself can be carried out continuously or in batches in conventional spray systems, with the inlet temperature being about 170 to about 200 °C and preferably about 180 to 185 °C, and the outlet temperature being about 70 to about 80 °C and preferably about 72 to 78 °C.

[0268] A key criterion for the usability of microcapsules is the weight ratio of core material to capsule wall material. While a high proportion of core material is desirable to maximize the capsules' utility, it is also necessary that the capsules still contain a sufficient proportion of capsule wall material to ensure stability.

[0269] According to the invention, it has proven particularly advantageous that the microcapsules are designed to have a weight ratio of core material to capsule wall material of 50 : 50 to 90 : 10, preferably 70 : 30 to 80 : 20.

[0270] The microcapsules produced according to the inventive method can be characterized by the d(0,5) value of their size distribution, i.e. that 50% of the produced capsules are larger, 50% of the capsules are smaller than this value.

[0271] The microcapsules according to the invention were produced from hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Furthermore, 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 the catalyst, and a modified starch as the protective colloid; beeswax was added as a separating agent. The pH of the aqueous phase before the emulsification step, as well as the pH of the emulsion or dispersion at the beginning of the reaction, was adjusted to 5.5 in each case.

[0272] To determine the particle size, the microcapsules according to the invention are dispersed in water in a dynamic process, and the particle size is then determined by laser diffraction. Depending on the size of the capsule, the laser beam is refracted differently and can thus be converted into a dimensional value. Mie theory was used for this purpose. A MALVERN Mastersizer 3000 was used for particle measurement.

[0273] The microcapsules according to the invention are characterized in that they have 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 microcapsules according to the invention and prior art microcapsules are shown in Figure 2 illustrated.

[0274] Direct comparison of the microcapsules shows that the inventive method can produce microcapsules with the same particle size distribution as prior art microcapsules based on polyurea / polyurethane structures without release agents, produced at a pH of 9.

[0275] In Figure 3 The IR images of the microcapsules according to the invention and of prior art microcapsules are shown.

[0276] The microcapsules according to the invention were produced from hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Furthermore, 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 the catalyst, and a modified starch as the protective colloid; beeswax was added as a separating agent. The pH of the aqueous phase before the emulsification step, as well as the pH of the emulsion or dispersion at the beginning of the reaction, was adjusted to 5.5. The prior art microcapsules were polyurea / polyurethane-based microcapsules without a separating agent, which were produced at a pH of 9.

[0277] The graph reveals clear differences in the bands, particularly in the fingerprint region. Vibrations in the range of 700 cm⁻¹ indicate the presence of CH₂ groups. At 1050 cm⁻¹, a significantly more intense band is observed compared to the state of the art, attributable to polyurethanes and polyesters. The polyesters originate from the ester bonds of the octenylsuccinate starch and from the ester bonds of the release agent (e.g., wax). At 1170 cm⁻¹, the band can be attributed to a polyester. At 1750 cm⁻¹, the vibration indicates a significantly increased proportion of carbonyl carbons. The double vibration in the range of 2500 to 3000 cm⁻¹ suggests an increased proportion of carbon chains resulting from the release agent.Furthermore, the comparison of the IR spectra shows that both the microcapsules according to the invention and the prior art microcapsules consist of a polyurea / polyurethane polymer.

[0278] The process according to the present invention for the production of polyurea / polyurethane microcapsules is advantageously characterized, among other things, by the fact that the individual crosslinking steps are carried out in a pH-dependent manner.

[0279] By optimizing the pH value during the emulsification and crosslinking steps of the process according to the invention, microcapsules with even better performance can be produced, i.e., without any loss or impairment in the functionality of the microcapsules, such as olfactory properties and positive secondary properties such as high stability, namely the ability to retain the active ingredient, compared to those produced without pH adjustment. Targeted pH adjustment improves stability, thereby reducing the free oil content and increasing the sensory performance of the microcapsules.

[0280] The inventive method enables the alternating deposition of defined polyurea- and polyurethane-based crosslinking units or crosslinking matrices around the core comprising the lipophilic active ingredient(s) by interfacial polymerization, thereby creating a stable and dense capsule wall or capsule shell. The main components of the capsule shell or capsule wall are essentially polyurea- or polyurethane crosslinking matrices or crosslinking units. Furthermore, the protective colloid (e.g., starch) can also be present in the capsule shell or capsule wall via polyurethane crosslinking. The incorporation of a release agent into the capsule shell or capsule wall further stabilizes and densifies it.

[0281] Furthermore, the process according to the invention is characterized by the fact that, preferably, protective colloid, amino acids, hydroxyl group donor as main components, and polyisocyanates are polymerized and / or cross-linked via specifically catalyzed mechanisms, thus enabling the production of bio-based and biodegradable microcapsules based on biocompatible polymers. Unlike prior art microcapsules, where polyisocyanates constitute a large proportion of the capsule shell material, the opposite is true here: In the microcapsules according to the invention, the polyisocyanates no longer function as the main material, but serve exclusively as cross-linkers for the amino acids and the other aforementioned components.

[0282] The process according to the invention thus makes it possible to replace a portion of the polyisocyanate with biodegradable wall materials such as protective colloids, amino acids, hydroxyl group donors, and release agents, thereby reducing the polyisocyanate content without any loss of functionality of the microcapsules, such as olfactory properties and positive secondary properties such as high stability, namely the ability to retain the active ingredient. Therefore, the process according to the invention makes it possible to produce microcapsules that exhibit excellent functionality while simultaneously being readily biodegradable.

[0283] Surprisingly, it has been found that the inventive method can be used to produce microcapsules with a reduced amount of polyisocyanate by up to 60%, without any loss of stability of the resulting microcapsules, as shown in the following exemplary embodiments. This allows microcapsules to be produced with a reduced amount of starting material isocyanate while maintaining the same amount of active ingredient to be encapsulated.

[0284] In a further aspect, the present invention relates to biodegradable polyurea / polyurethane microcapsules or polyurea / polyurethane microcapsule dispersions obtained according to the method of the invention, wherein the microcapsule comprises: (i) a core comprising at least one lipophilic active ingredient; and (ii) a hardened capsule shell comprising a reaction product of a polymerization and / or crosslinking of at least one polyisocyanate with two or more isocyanate groups, in the presence of at least one protective colloid with at least one first amino acid or an amino acid hydrochloride, a further polymerization and / or crosslinking with at least one hydroxyl group donor, and a further polymerization and / or crosslinking with at least one second amino acid, wherein the alternating polymerization and / or crosslinking of polyisocyanate units with functional amino groups orHydroxyl groups in a stable capsule shell resulting from alternately defined and dense crosslinking units based on polyurethane and polyurea, which are spatially crosslinked with each other and with each other; and at least one release agent.

[0285] The biodegradable polyurea / polyurethane microcapsules obtained according to the inventive method are characterized in that they are composed of or comprise: (i) a core comprising at least one lipophilic active ingredient; and (ii) a hardened capsule shell comprising: a reaction product of a polymerization and / or crosslinking of at least one polyisocyanate with two or more isocyanate groups, in the presence of at least one protective colloid with at least one first amino acid or an amino acid hydrochloride, a further polymerization and / or crosslinking with at least one hydroxyl group donor, and a further polymerization and / or crosslinking with at least one second amino acid, wherein the alternating polymerization and / or crosslinking of polyisocyanate units with functional amino groups or hydroxyl groups results in a stable capsule shell of alternately defined and dense polyurethane- and polyurea-based crosslinking units that are spatially crosslinked with each other and with each other; and at least one release agent.

[0286] The alternating polymerization and / or crosslinking of polyisocyanate units with functional amino groups or hydroxyl groups results in a stable capsule wall made of alternately defined and dense, and therefore stable, crosslinking matrices or crosslinking units based on polyurethane and polyurea.

[0287] In a preferred embodiment, the capsule shell of the manufactured biodegradable polyurea / polyurethane microcapsule comprises or consists of: (α) a first crosslinking matrix or first crosslinking units resulting from a polymerization and / or crosslinking of at least one polyisocyanate with two or more polyisocyanate groups, with at least one protective colloid, and with at least one first amino acid; (β) a second crosslinking matrix or second crosslinking units resulting from a crosslinking of at least one polyisocyanate with two or more polyisocyanate groups, with at least one hydroxyl group donor; (γ) a third crosslinking matrix or third crosslinking units resulting from a crosslinking of at least one polyisocyanate with two or more polyisocyanate groups, with at least one second amino acid; and (δ) at least one release agent; and (ε) optionally a further polyester-based crosslinking matrix or further crosslinking units.

[0288] The first crosslinking matrix or crosslinking units of the capsule shell of the microcapsule according to the invention are a polyurea-based network. The second crosslinking matrix or crosslinking units are a polyurethane-based network, and the third crosslinking matrix or crosslinking units are another polyurea-based network. The optional fourth crosslinking matrix or crosslinking units are another polyester-based network. The composition of the polyurea and / or polyurethane and / or polyester crosslinking matrices or crosslinking units depends on the polyisocyanate and crosslinking agent used, i.e., protective colloid, first amino acid, hydroxyl group donor, and second amino acid.

[0289] In addition to the polyurethane and polyurea formation described above, the crosslinking steps described previously also produce byproducts due to the reactivity of the polyisocyanates. These byproducts include urea, allophanate, biuret, uretidione, carbodiimide, uretonimine, etc., as described in MF Sonnenschein, Introduction to Polyurethane Chemistry, Polyurethanes: Science, Technology, Markets, and Trends, First Edition, 2015, John Wiley & Sons, pages 105 to 126. These byproducts are components of the capsule shell or capsule wall.

[0290] By constructing the capsule wall based on several individual, defined, and alternating crosslinking matrices or units, it is possible to produce particularly stable microcapsules with excellent sensory performance, while simultaneously significantly reducing the number of shell components. Finally, the stability of the capsule shell is further enhanced by the incorporation of a release agent.

[0291] Surprisingly, polyurea / polyurethane fragrance capsules produced according to the inventive method exhibit higher stability and a reduction in unintentionally escaping perfume oil, as shown in the following exemplary embodiments, which can be attributed in particular to more efficient encapsulation of the fragrances.

[0292] Surprisingly, it has been found that the inventive method can be used to produce microcapsules which, compared to the polyurea / polyurethane microcapsules of the prior art, exhibit stability that is at least 1.5 times, preferably at least 2 times, better, as illustrated in the following exemplary embodiments.

[0293] The microcapsules according to the invention also have a content of free hydrophobic active ingredient of 0.5 wt.% or less, preferably a content of ≤ 0.3 wt.% or less, and even more preferably a content of ≤ 0.2 wt.%.

[0294] Furthermore, the polyurea / polyurethane microcapsules according to the invention 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 losses. The microcapsules according to the invention therefore show a significantly higher sensory intensity when fragrance is released by opening the capsules using mechanical friction or pressure, as demonstrated in Figure 5 This is illustrated. The polyurea / polyurethane microcapsules according to the invention show a significant improvement in sensory performance (fragrance release) compared to prior art capsules by a factor of at least 1.5, preferably at least 1.75, and even more preferably by a factor of at least 2.

[0295] With increasing degree of cross-linking, i.e. with increasing polyisocyanate content, the stability of the microcapsules also increases, but at the same time the ability of the capsule shell to biodegrade decreases, as illustrated in the exemplary embodiments. Figure 6 This generally shows the correlation between microcapsule stability, performance, and biodegradability depending on the degree of cross-linking. For example, with very stable microcapsules, performance, such as sensory performance, is lower because the number of microcapsules that rupture through rubbing, pressure, etc., and release the active ingredients decreases.

[0296] The polyurea / polyurethane microcapsules according to the invention have a reduced amount of polyisocyanate by up to 60% compared to prior art polyurea / polyurethane microcapsules, without any loss of stability or the loading capacity of the microcapsules with the active ingredient to be encapsulated, as shown in the following exemplary embodiments. In contrast to prior art microcapsules, the isocyanates no longer function as the main material of the capsule shell or capsule wall, but serve exclusively as crosslinkers for the amino acids and other main components of the capsule shell, such as protective colloid and hydroxyl group donors. The absolute polyisocyanate content of the microcapsules described herein corresponds to only one-sixtieth of the total capsule containing the active ingredient(s).Assuming that the raw materials react quantitatively, it can be assumed that with 100% wall material exactly 1 / 5 of the wall material consists of polyisocyanate and, due to the small quantity in which it is present, can only be considered a crosslinking agent.

[0297] Due to the lower polyisocyanate content in the capsule shell or capsule wall on the one hand, and the use of a release agent on the other, the microcapsules according to the invention are more biodegradable than capsules according to the prior art. Microcapsules according to the invention, produced using a release agent, exhibit significantly better biodegradability, as shown in the following exemplary embodiments.

[0298] Biodegradability is the ability of organic material to be broken down into water, carbon dioxide (CO2) and biomass after a specified period of time under defined temperature, oxygen and humidity conditions in the presence of microorganisms or fungi.

[0299] According to OECD 301F, a microcapsule is considered to be biodegradable immediately if more than 60% of the wall material has degraded after 28 days.

[0300] The microcapsules according to the invention exhibit a biodegradability according to OECD 301 F of ≥ 20% after 28 days, preferably a biodegradability of ≥ 50%, more preferably a biodegradability of ≥ 70% and most preferably a biodegradability of ≥ 90%.

[0301] The combination of the starting components on the one hand and the crosslinking sequence on the other enable microcapsules according to the invention with sufficient stability (mechanically and diffusion-stable in application), high sensory performance, and simultaneously excellent biodegradability. This has broken the previously established correlation between sensory performance, high crosslinking, and biodegradability.

[0302] Furthermore, the microcapsule according to the invention is a universal capsule with which, according to current knowledge, a wide range of fragrance or flavoring substances can be encapsulated, even fragrance or flavoring substances that have an aldehyde, carboxylic acid or ester functionality, so that there are no restrictions against individual active ingredients.

[0303] Due to their advantageous properties, in particular their stability and the targeted release of the active ingredients, the microcapsules according to the invention are suitable for a wide range of applications and in particular for use in household products, textile care products, detergents, fabric softeners, cleaning agents, scent boosters, scent lotions and fragrance enhancers, cosmetics, personal care products, agricultural products, pharmaceutical products, printing coatings for paper and the like.

[0304] The present invention therefore relates in a further aspect to the use of the biodegradable polyurea / polyurethane microcapsules according to the invention or a dispersion of the polyurea / polyurethane microcapsules according to the invention (microcapsule slurry) for the manufacture of household products, textile care products, detergents, fabric softeners, cleaning agents, scent boosters, scent lotions or fragrance enhancers in liquid or solid form, cosmetics, personal care products, agricultural products, pharmaceutical products, printing coatings for paper and the like.

[0305] Finally, the present invention relates to household products, textile care products, detergents, fabric softeners, cleaning agents, scent boosters, scent lotions and fragrance enhancers, cosmetics, personal care products, agricultural products, pharmaceutical products, printing coatings for paper and the like, which comprise the biodegradable polyurea / polyurethane microcapsules according to the invention or a dispersion of the polyurea / polyurethane microcapsules according to the invention. Examples of implementation

[0306] The biodegradable polyurea / polyurethane microcapsules according to the invention and their advantageous properties are described in more detail with reference to the following examples. Example of implementation no. 1 - Wall materials compared

[0307] Table 1: ingredient State of the art / % *) According to the invention *) Isocyanates 4,8 1,7 Protective colloid 0,3 2,2 First amino acid - 1,3 Hydroxyl group donor - 2,6 Second amino acid / basic amine 1,9 0,4 Long-chain acids / alcohols / esters - 3,5 *) All content data refers to the complete microcapsule including oil

[0308] The microcapsules according to the invention have a significantly lower polyisocyanate content, by up to 60%. In contrast to the prior art microcapsules, the isocyanates no longer function as the main material and serve exclusively as crosslinking agents for the amino acids and other components of the capsule materials. Example of implementation No. 2 - Capsule stability

[0309] The following stability data refers to a test at 40°C in a commercially available formulation, such as scent booster or fabric softener.

[0310] In the following examples, capsules chosen as prior art are those whose capsule walls consist exclusively of a polyurea network. These capsules were generally produced without a catalyst and the synthesis was carried out at a pH of 9. Polyvinyl alcohol was used as the protective colloid.

[0311] The free oils were determined by allowing the slurry to stand in isopropanol for 30 seconds. The oil content was then determined by SPME followed by GC / MS. Example 1 - Capsule stability with and without pH optimization

[0312] The behavior of the free oils was determined by varying the pH value. Microcapsules according to the invention were produced using an isocyanate mixture consisting of hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Furthermore, 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 the catalyst, and a modified starch was used as the protective colloid. The starch used was in the form of a succinate. Beeswax was used as the wax. TomCap was used as the phase to be encapsulated. The non-optimized pH value of the emulsion or dispersion at the beginning of the respective reaction was 8.5, and the optimized pH value of the emulsion or dispersion at the beginning of the respective reaction was 5.5. Table 2: PH value Stability / % (4 weeks Scent Booster at 40 °C) pH value = 8.5 (not optimized) 25 pH value = 5.5 (pH value optimized) 47

[0313] Apparently, the stability of the microcapsules is significantly improved at a slightly acidic pH. The capsules are considered stable at a free oil content of < 1%. The lower the free oil content, the more stable the capsule. Example 2 - Capsule stability depending on pH value

[0314] The behavior of the free oils was determined by varying the pH value. Microcapsules according to the invention were produced using an isocyanate mixture consisting of hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Furthermore, lysine HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and histidine as the second amino acid. DABCO was used as the catalyst, and a modified starch was used as the protective colloid. The starch used was in the form of a succinate. Beeswax was used as the wax. TomCap was used as the phase to be encapsulated. Table 3: PH value Stability / % 1 week 40°C Softener 4 weeks 40°C Softener 2 - - 3 22 - 4 43 33 5 56 47 6 57 43 7 - - 8 21 - 9 25 - 10 28 - 11 - -

[0315] The optimal pH value of the emulsion or dispersion, which the emulsion or dispersion has at the beginning of the respective reactions in the process according to the invention, is in the range of 4 to 7 in order to produce stable microcapsules. Example 3 - Capsule stability depending on the polyisocyanate composition (comparison of single polyisocyanate and combination of two different polyisocyanates)

[0316] Microcapsules according to the invention were produced using different single polyisocyanates or a combination of two different polyisocyanates, guanidinium carbonate, polyvinyl alcohol as a protective colloid with TomCap as a perfume oil: Table 4: Isocyanates Free Oil / % Stability / % 3 days at 50°C in fabric softener 10 days at 50°C in fabric softener Hexamethylene diisocyanate / 4, 4'diphenylmethane diisocyanate 80:20 0,068 80 74 Hexamethylene diisocyanate 0,065 43 32 Pentamethylene diisocyanate 0,113 72 62 4, 4'Diphenylmethane diisocyanate 0,111 78 69

[0317] The use of a combination of two different isocyanates resulted in microcapsules that exceed the stability of single-isocyanate systems. Therefore, the use of a mixture of two different isocyanates is preferred. Example 4 - Capsule stability depending on the polyisocyanate composition (comparison of aliphatic-aliphatic polyisocyanate mixture and alpha-aromatic polyisocyanate mixture)

[0318] Microcapsules according to the invention were produced using an aliphatic-aliphatic polyisocyanate mixture and an aliphatic-aromatic polyisocyanate mixture as follows:

[0319] Aliphatic-aliphatic polyisocyanate mixture: Pentamethylene diisocyanate and hexamethylene diisocyanate in a ratio of 50:50. Aliphatic-aromatic isocyanate mixture: hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Furthermore, 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 the catalyst, and a modified starch as the protective colloid. TomCap was used as the encapsulation phase. Beeswax was used as the wax. The starch used is in succinate form. Table 5: Isocyanate mixture Free Oil / % aliphatic-aliphatic 0,49 aliphatic-aromatic 0,09

[0320] The free oil content in both samples is significantly below 1%, meaning both capsules are considered stable. The microcapsule made from an aliphatic-aliphatic polyisocyanate mixture is just as stable as a microcapsule made from an aliphatic-aromatic polyisocyanate mixture. Example 5 - Capsule stability with and without additional catalyst

[0321] Microcapsules according to the invention were produced using an isocyanate mixture consisting of hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Furthermore, lysine HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and histidine as the second amino acid. DABCO was used as the catalyst, and a modified starch was used as the protective colloid. The starch used was in the form of a succinate. Beeswax was used as the wax. TomCap was used as the phase to be encapsulated. In addition, another catalyst was used in the production process. Table 6: Para-toluenesulfonic acid Stability / % 1 week 40°C Softener 4 weeks 40°C Softener With 52 49 Without 32 24

[0322] The microcapsules produced using an additional catalyst are twice as stable after four weeks as microcapsules produced without the use of an additional catalyst. Example 6 - Capsule stability with and without first catalyst

[0323] Microcapsules according to the invention were produced using an isocyanate mixture consisting of hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Furthermore, lysine HCl was used as the first amino acid, glycerol as the hydroxyl group donor, and histidine as the second amino acid. Para-toluenesulfonic acid was used as the second catalyst, and a modified starch was used as the protective colloid. The starch used was in the form of a succinate. Beeswax was used as the wax. TomCap was used as the phase to be encapsulated. Table 7: DABCO Stability / % 1 week 40°C Softener 4 weeks 40°C Softener With 54 46 Without 7 -

[0324] The microcapsules produced using a first catalyst are significantly more stable, which is why the use of a polyurethane catalyst, such as DABCO, is essential. Example of implementation no. 3- Biodegradability and free oil in relation to the amount of crosslinking agents (isocyanates)

[0325] The free oil content was determined as described above.

[0326] Biodegradability according to OECD 301F was determined as follows: Degradability of the wall material in a non-preadapted inocolumn, measured by manometric respiration (oxygen consumption). Table 7: Crosslinker quantity / % Free Oil / % Biodegradability / % according to OECD 301F within 28 days 4,3 0,13 30 3,2 0,22 42 2,0 0,71 96

[0327] Biodegradability increases as the amount of polyisocyanate (crosslinker) decreases. Surprisingly, the increase in free oil is very small, which suggests the capsules are stable. Example No. 4 - Comparison of biodegradability with and without release agents

[0328] Table 8: ingredient Microcapsule without separating agent / % *) Microcapsule with separating agent / % *) Isocyanates 1,8 1,7 Protective colloid 2,2 2,2 amino acid 1,4 1,3 Hydroxyl group donor 2,7 2,6 amino acid 1,8 1,7 Release agent - 3,5 Biodegradability of capsule wall material 6,7 % 96 % according to OECD 301F within 28 days according to OECD 301F within 28 days *) All content data refers to the complete microcapsule including oil.

[0329] The capsules according to the invention show that a biodegradability of 96% is present, which means that the wall material can be considered immediately biodegradable. Example No. 6 - Comparison of biodegradability with regard to sodium sulfate and toxicity control

[0330] The biodegradability of the wall material according to OECD 301 F was tested using the microcapsules according to the invention of embodiment no. 5. Sodium benzoate was used as a process control and a mixture of the microcapsules according to the invention and sodium benzoate as a toxicity control. Test replicate 1 and 2 = Capsule according to the invention; Procedure control replicate 1 and 2 = Sodium sulfate; Toxicity control = Combination of capsule according to the invention and sodium sulfate to control the toxicological effect

[0331] The test results are in Figure 4 shown.

[0332] The capsules according to the invention show a biodegradability of 96% on average across two samples, which suggests that the wall material can be considered immediately biodegradable. Toxicity testing also demonstrates degradability, proving that the wall material of the capsule according to the invention is not persistent. Example No. 7 - Comparison of biodegradability with and without wax

[0333] The microcapsules according to the invention were produced using an isocyanate mixture consisting of hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Furthermore, 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 the catalyst, and a modified starch as the protective colloid. The wall material was then separated using a centrifuge, a rotary evaporator, and a vacuum drying oven. Ethyl acetate was used as the phase to be encapsulated. The waxes used are listed in the table below. The starch used is in the form of a succinate. Table 9: Waxes Biodegradability according to OECD 301 F after 28 days / % No wax 12 beeswax 96 Sunflower seed wax 72

[0334] According to OECD 301F, both capsules are considered biodegradable due to the use of wax. The use of wax is surprising in that, despite the small amount of wax, the biodegradability increases disproportionately. Example No. 8 - Sensory Test

[0335] For sensory evaluation, the microcapsules according to the invention were compared with prior art microcapsules, i.e., microcapsules based on polyurea / polyurethane structures without separating agents and a pH value of 9.

[0336] The microcapsules according to the invention were produced from hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 75:25. Furthermore, 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 the catalyst, and a modified starch as the protective colloid; beeswax was added as a separating agent. The pH value of the emulsion or dispersion at the beginning of the respective reactions was adjusted to pH 5.5.

[0337] The sensory evaluation was carried out as follows: The aforementioned microcapsules were each incorporated into a fabric softener with an oil concentration of 0.2 wt% and then washed. Smelling was performed on blended cotton and polyester cloths.

[0338] Twelve test subjects rated the fragrance intensity of blended-fiber towels after washing on a scale of 1 (no odor) to 9 (very strong odor). Fragrance release was assessed in three steps. The first step involved smelling an untreated towel. The second step involved smelling a lightly kneaded towel; for this, the towel was subjected to slight mechanical stress by repeatedly moving it back and forth between the hands, thus breaking the fragrance capsules. The third step involved smelling the towels after they had been vigorously rubbed, again breaking the fragrance capsules.

[0339] The microcapsules according to the invention have a significantly better performance, as demonstrated in Figure 5This is illustrated. This can be attributed to the targeted modification of the system: through pH-optimized cross-linking and the use of a separating agent, a stable capsule wall structure is formed, which makes the capsules smell better, yet is still biodegradable.

Claims

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

2. Process according to claim 1, wherein the at least one polyisocyanate having two or more isocyanate groups is selected from the group consisting of aliphatic, cycloaliphatic, hydroaromatic, aromatic or heterocyclic polyisocyanates, substitution products thereof, and mixtures of the aforementioned compounds, in particular wherein the at least one polyisocyanate comprises two aliphatic polyisocyanates or one aliphatic and one aromatic polyisocyanate, in particular wherein the at least one polyisocyanate comprises polyisocyanates in an alternately monomeric, oligomeric or polymeric structure with different chain lengths.

3. Process according to any of the preceding claims 1 or 2, wherein the at least one lipophilic active ingredient to be encapsulated is selected from the group consisting of fragrances, flavorings, cooling agents, TRPV1 and TRPV3 modulators, substances which cause a pungent taste or a warmth or heat sensation on the skin or mucous membranes or a tingling sensation in the mouth or throat, active substances with a pungent or acrid or astringent effect, pesticides, biocides, insecticides, substances from the group of repellents, food additives, cosmetic active ingredients, pharmaceutical active ingredients, dyes, dye precursors, fluorescent dyes, agrochemicals, optical brighteners, solvents, waxes, silicone oils, lubricants, print coatings for paper, and mixtures of two or more of the aforementioned active ingredients, wherein substances which cause a pungent taste or a warmth or heat sensation on the skin or mucous membranes are selected from the group consisting of: paprika powder, chili pepper powder, extracts of paprika, extracts of pepper, extracts of chili pepper, extracts of ginger roots, extracts of grains of paradise (Aframomum melegueta), extracts of para cress (Jambu oleoresin; Spilanthes acmella, or Spilanthes oleracea), extracts of Japanese pepper (Zanthoxylum piperitum), extracts of Kaempferia galanga, extracts of Alpinia galanga, extracts of water pepper (Polygonium hydropiper), capsaicinoids, in particular capsaicin, dihydrocapsaicin or nonivamide; gingerols, in particular gingerol-[6], gingerol-[8] or gingerol-[10]; shogaols, in particular shogaol-[6], shogaol-[8] or shogaol-[10]; gingerdiones, in particular gingerdione-[6], gingerdione-[8] or gingerdione-[10]; paradoles, in particular paradole-[6], paradole-[8] or paradole-[10]; dehydrogingerdiones, in particular dehydrogingerdione-[6], dehydrogingerdione-[8] or dehydrogingerdione-[10]; piperine; piperine derivatives; ethyl 2-(4-hydroxy-3-methoxyphenyl)acetate and 3-phenylpropyl 2-(4-hydroxy-3-methoxyphenyl)acetate, and mixtures thereof; active substances with a pungent or acrid effect are 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; substances which cause a tingling sensation in the mouth or throat are selected from the group consisting of: 2E,4E-decadienoic acid N-isobutylamide (trans-pellitorin); 2E,4Z-decadienoic acid N-isobutylamide (cis-pellitorin); 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-decadienoic acid N-(2-methylbutyl)amide; 2E,4E-decadienoic acid N-piperide (achilleamide); 2E,4E-decadienoic acid N-piperide (sarmentin); 2E-decenoic acid N-isobutylamide; 3E-decenoic acid N-isobutylamide; 3E-nonenoic acid N-isobutylamide; 2E,6Z,8E-decatrienoic acid N-isobutylamide (spilanthol); 2E,6Z,8E-decatrienoic acid N-([2S]-2-methylbutyl)amide (homospilanthol); 2E,6Z,8E-decatrienoic acid N-([2R]-2-methylbutyl)amide; 2E-decen-4-ynoic acid N-isobutylamide; 2Z-decen-4-ynoic acid N-isobutylamide; 2E,6Z,8E,10E-dodecatetraenoic acid N-(2-methylpropyl)amide (alpha-sanshool); 2E,6Z,8E,10E-dodecatetraenoic acid N-(2-hydroxy-2-methylpropyl)amide (alpha-hydroxysanshool); 2E,6E,8E,10E-dodecatetraenoic acid N-(2-hydroxy-2-methylpropyl)amide (gamma-hydroxysanshool); 2E,4E,8Z,10E,12E-tetradecapentaenoic acid N-(2-hydroxy-2-methylpropyl)amide (gamma-hydroxysanshool); 2E,4E,8E,10E,12E-tetradecapentaenoic acid N-(2-hydroxy-2-methylpropyl)amide (gamma-hydroxyisosanshool); 2E,4E,8Z,10E,12E-tetradecapentaenoic acid N-(2-methyl-2-propenyl)amide (gamma-dehydrosanshool); 2E,4E,8Z,10E,12E-tetradecapentaenoic acid N-(2-methylpropyl)amide (gamma-sanshool); 2E,4E,8Z,11Z-tetradecatetraenoic acid N-(2-hydroxy-2-methylpropyl)amide (bungeanool); 2E,4E,8Z,11E-tetradecatetraenoic acid N-(2-hydroxy-2-methylpropyl)amide (isobungeanool); 2E,4E,8Z-tetradecatrienoic acid N-(2-hydroxy-2-methylpropyl)amide (dihydrobungeanool) and 2E,4E-tetradecadienoic acid N-(2-hydroxy-2-methylpropyl)amide (tetrahydrobungeanool), and mixtures thereof; active substances with an astringent effect are selected from the group consisting of: catechins, in particular epicatechins, gallocatechins, epigallocatechins and respective gallic acid esters thereof, in particular epigallocatechin gallate or epicatechin gallate, oligomers thereof (procyanidins, proanthocyanidins, prodelphinidins, procyanirins, thearubigenins, theogallins) and C- and O-glycosides thereof; dihydroflavonoids such as dihydromyricetin, taxifolin and C- and O-glycosides thereof, flavonols such as myricetin, quercetin and C- and O-glycosides thereof such as quercetrin, rutin, gallic acid esters of carbohydrates such as tannin, pentagalloylglucose or reaction products thereof such as elligatannin, aluminum salts, and mixtures thereof.

4. Process according to any of the preceding claims 1 to 3, wherein the at least one lipophilic active ingredient to be encapsulated is selected from the group consisting of fragrances or flavorings having an aldehyde, carboxylic acid or ester functionality.

5. Process according to any of the preceding claims 1 to 4, wherein the protective colloid is selected from the group consisting of - diols, in particular ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, isomeric butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-dodecanediol, and - polyols, preferably triols, in particular glycerol and ethoxylation and propoxylation products thereof, trimethylolpropane and ethoxylation and propoxylation products thereof, polyvinyl alcohol (PVOH) and derivatives thereof, in particular ammonium- or sulfonate-functionalized polyvinyl alcohols, polyphenols, in particular 1,3,5-trihydroxybenzene, polysaccharides, in particular glucose, starches or chemically, mechanically and / or enzymatically modified starches, cellulose derivatives such as hydroxyethylcellulose, in particular quaternized hydroxyethylcellulose, and carboxymethylcellulose, - polyvinylpyrrolidone, maleic acid-vinyl copolymers, sodium lignosulfonates, maleic anhydride-styrene copolymers, ethylene-maleic anhydride copolymers, copolymers of ethylene oxide, propylene oxide and acid esters of polyethoxylated sorbitol, sodium dodecyl sulfate, - animal and vegetable polymers, proteins, gelatin, olibanum resin, shellac, lignin, chitosan, saponin, and mixtures of the aforementioned compounds.

6. Process according to any of the preceding claims 1 to 5, wherein the protective colloid is used in combination with starch.

7. Process according to any of the preceding claims 1 to 6, wherein the 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.

8. Process according to any of the preceding claims 1 to 7, wherein the first catalyst is selected from the group consisting of diazobicyclo[2.2.2]octane, bismuth catalyst and tin catalyst, and mixtures of the aforementioned catalysts; and the optional further catalyst is selected from the group consisting of paratoluenesulfonic acid, sulfuric acid, germanium oxide or enzymatic catalysts, in particular Candida antarctica Lipase B.

9. Process according to any of the preceding claims 1 to 8, wherein the hydroxyl group donor is a polyol having two or more hydroxyl functional groups, in particular glycerol, propylene glycol, 1,3,5-trihydroxybenzene, starches, modified starches, cellulose derivatives such as hydroxyethylcellulose, in particular quaternized hydroxyethylcellulose, or carboxymethylcellulose, or mixtures thereof.

10. Process according to any of the preceding claims 1 to 9, wherein the at least one second amino acid is selected from the group consisting of arginine, histidine, aspartic acid, lysine, glycine, alanine, proline, cysteine, glutamine, leucine, serine, tryptophan, valine, threonine, ornithine, and mixtures thereof.

11. Process according to any of the preceding claims 1 to 10, wherein the at least one release agent is selected from the group consisting of - long-chain, aliphatic, linear or branched, saturated or unsaturated carboxylic acids with 12 to 30 C atoms, in particular lauric acid (12:0), tridecanoic acid (13:0), myristic acid (14:0), pentadecanoic acid (15:0), palmitic acid (16:0), margaric acid (17:0), stearic acid (18:0), nonadecanoic acid (19:0), arachidic acid (20:0), heneicosanoic acid (21:0), behenic acid (22:0), lignoceric acid (24:0), cerotinic acid (26:0), montanic acid (28:0) and melissic acid (30:0); myristoleic acid (14:1), palmitolic acid (16:1), margaroleic acid (17:1), petroselinic acid (18:1), oleic acid (18:1), elaidic acid (18:1), vaccenic acid (18:1), gadoleic acid (20:1), gondoic acid (20:1), cetoleic acid (22:1), erucic acid 822:1), nervonic acid (24:1), linoleic acid (18:2), alpha-linolenic acid (18:3), gamma-linolenic acid (18:3), calendulic acid (18:3), punicic 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), docosatetraenoic acid (ADA) (22:4), docosapentaenoic acid (DPA-3) (22:5), docosahexaenoic acid (22:6) and tetracosahexaenoic acid (24:6); phytanic acid; - long-chain, aliphatic, linear or branched, saturated or unsaturated primary alcohols with 12 to 30 C 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 melissyl alcohol (30:0); palmitoleyl alcohol (16:1), oleyl alcohol (18:1), elaedyl alcohol (18:1), linoleyl alcohol (18:2), gamma-linolenyl alcohol (18:3); - esters of long-chain, aliphatic, saturated carboxylic acids with 12 to 30 C atoms with long-chain, aliphatic primary alcohols with 12 to 30 C atoms, in particular lauryl palmitate, myricyl palmitate, cetyl arachinate and stearyl behenate; and - animal and vegetable waxes, in particular wool wax, China wax, beeswax, sunflower seed wax, rice bran wax, carnauba wax, pinova wax, rapeseed wax, soy wax, candelilla wax, jojoba oil, cork wax, guaruma wax, cotton wax, flax wax, peat wax, rose wax, jasmine wax, peetha wax from wash gourd, as well as myrtle wax (Myrica cerifera), wax fig wax, berry wax; and mixtures of the aforementioned release agents.

12. Biodegradable polyurea / polyurethane microcapsule or polyurea / polyurethane microcapsule dispersion, obtained by the method according to one or more of the preceding claims 1 to 11, wherein the microcapsule comprises (i) a core, comprising at least one lipophilic active ingredient; and (ii) a cured capsule shell, comprising: - a reaction product from a polymerization and / or crosslinking of at least one polyisocyanate having two or more isocyanate groups, in the presence of at least one protective colloid, with at least one first amino acid or an amino acid hydrochloride, a further polymerization and / or crosslinking with at least one hydroxyl group donor, and a further polymerization and / or crosslinking with at least one second amino acid, wherein the alternating polymerization and / or crosslinking of polyisocyanate units with functional amino groups or hydroxyl groups results in a stable capsule shell formed of alternately defined and dense crosslinking units based on polyurethane and polyurea, which are spatially crosslinked to each other and among each other; and - at least one release agent.

13. Biodegradable polyurea / polyurethane microcapsule or polyurea / polyurethane microcapsule dispersion according to claim 12, which has a biodegradability according to OECD 301 F after 28 days of ≥20% and / or has a free hydrophobic active ingredient content of ≤0.3 wt%.

14. Use of the biodegradable polyurea / polyurethane microcapsule or polyurea / polyurethane microcapsule dispersion according to claim 12 to produce household products, textile care products, detergents, fabric softeners, cleaning agents, scent boosters, scent lotions or scent enhancers in liquid or solid form, cosmetics, personal care products, perfume compositions, agricultural products, pharmaceutical products or print coatings for paper and the like.

15. Household products, textile care products, detergents, fabric softeners, cleaning agents, scent boosters, scent lotions and scent enhancers, cosmetics, personal care products, perfume compositions, agricultural products, pharmaceutical products or print coatings for paper and the like, comprising a biodegradable polyurea / polyurethane microcapsule or polyurea / polyurethane microcapsule dispersion according to claim 12.