METHOD FOR THE MANUFACTURING OF MICROCAPLES

Description

Field of the invention

[0001] The present invention relates to a process for producing isocyanate-based or isothiocyanate-based microcapsules with improved stability toward active ingredients containing carboxylic acid, aldehyde, and / or ester as core material. Furthermore, the present invention relates to microcapsules obtainable by the process according to the invention. Furthermore, the present invention relates to microcapsules, suspensions of such microcapsules, and the use of the microcapsules and suspensions as components of detergents, fabric softeners, cleaning agents, fragrance enhancers in liquid or solid form, cosmetics, personal care products, agricultural products, and pharmaceutical products.

[0002] The term "encapsulation" generally refers to a technique by which finely dispersed solid, liquid, or gaseous substances are surrounded by a film-forming shell made of polymeric or inorganic wall materials, thus immobilizing them. During production, the polymers are deposited on the encapsulated substances after emulsification and coacervation or interfacial polymerization. Encapsulation is thus a form of inclusion immobilization. The substances or active ingredients enclosed in the capsules are generally referred to as the core material.

[0003] The goal is to protect the active components, known as active ingredients, and to release them at a specific time. The active ingredients or active components often cannot be used directly for various reasons (e.g., due to their solubility, reactivity, stability, etc.), or specific effects are to be achieved through microencapsulation (e.g., release curves for controlled release, unique selling points, etc.).

[0004] For a diameter in the range > 100 µm, individual substance or active ingredient particles are coated using various spray technologies, while liquids are encapsulated using dropletization processes.

[0005] Of particular interest are so-called microcapsules which have diameters in the range of approximately 0.0001 to 5, preferably 0.001 to 0.5 and in particular 0.005 to 0.1 mm.

[0006] For microcapsules with a diameter of less than 100 µm, however, encapsulation is only possible by depositing so-called wall-forming agents at a phase interface. In the industrially used manufacturing process for this, an emulsion or suspension of the hydrophobic core material is created in water. The monomers in the outer phase accumulate in a layer around the emulsion droplets or the dispersed solid particles of the core material and polymerize to form a compact shell. Depending on the wall material and degree of cross-linking, individual properties of the microcapsules can be achieved.

[0007] Encapsulation is divided into two types: Matrix encapsulation: Here, the active ingredient(s) or active component(s) are homogeneously mixed with the shell component ("matrix"), resulting in a particle in which the active ingredient(s) or active component(s) are evenly distributed. Typically, release is determined either by the diffusion of the active component(s) into the environment or by the degradation rate of the matrix. Core-shell encapsulation: The active ingredient(s) or active component(s) forming the core are encased in a shell material. This creates a true capsule with one or more shells. A shell rupture usually results in complete release of the core material within a short time. However, it is also possible to achieve extremely slow release by choosing the right shell.

[0008] Due to their properties, microcapsules are used in the printing industry, the food industry (vitamins, flavors, plant extracts, enzymes, microorganisms), agrochemicals (fertilizers, pesticides), the animal feed industry (minerals, vitamins, enzymes, medicines, microorganisms), the pharmaceutical industry, the detergent industry and the cosmetics industry, among others.

[0009] The encapsulation of an active ingredient with a suitable wall material (coating material) can be done for several reasons: Conversion of liquids into a manageable powder form (e.g. coating of vegetable oils, fats); time-controlled release of substances (dosage control, depot effect in pharmaceuticals, pesticides and fertilizers); masking of taste, odor and color (e.g. bitter or pungent flavorings); protection from light, oxidation, heat, acids or bases (e.g. vitamins, flavorings, etc.); protection against moisture (e.g. hygroscopic salts or minerals); delaying the loss of volatile components (e.g. flavorings); preventing premature chemical reactions with other mixture components; improved handling before or during processing (flow properties, dust formation); protection of personnel from harmful or unpleasant materials (chemicals, flavor concentrates); or improved solubility / suspensibility through surface modification.

[0010] The contents of microcapsules can be released in a variety of ways, with four typical mechanisms being considered: The capsules are destroyed mechanically by crushing or shearing. This mechanism is used, for example, in carbonless paper. The capsules are destroyed by melting the wall material. According to this mechanism, ingredients in baking mixes such as raising agents or flavorings are only released during the baking process. The capsules are destroyed by dissolving the wall material. This mechanism is used, for example, in washing powder so that encapsulated ingredients such as enzymes are only released during the washing process. The capsules remain intact, and the capsule contents are gradually released by diffusion through the capsule wall. Using this mechanism, for example, a slow and even release of active pharmaceutical ingredients in the body can be achieved.

[0011] Many everyday items such as cleaning products, fabric softeners, washing powders, liquid detergents, shower gels, shampoos, deodorants, and polylotions are now scented with fragrances or fragrance blends. Very often, the fragrances interact with other ingredients in the formulation or lead to premature evaporation of the more volatile components of a perfume. This usually leads to the fragrance impression changing over time or even disappearing completely.

[0012] The microencapsulation of such fragrance mixtures offers the possibility of reducing or completely preventing interactions in the perfumed product or the evaporation of the volatile fragrance components.

[0013] The microcapsules, which are both chemically and mechanically stable, are based on aminoplast resins, for example, which are used as wall or shell materials. In addition to the high density of the capsule shell, it is also very resistant to reactive chemicals. The production of these capsules is simplified by first creating an O / W emulsion under strong shear and in the presence of emulsifiers. This emulsion contains the water-soluble monomer, a so-called amine-formaldehyde precondensate, and the water-insoluble, hydrophobic active ingredient, such as a perfume oil. The polycondensation is initiated by a pH change, for example, by adjusting the pH to approximately 3.5 by adding acid. The polycondensates deposit on the oil droplets in the emulsion and gradually envelop them. After the polycondensation is complete, the emulsion transforms into a microcapsule dispersion.However, the capsules still have a soft, elastic shell, which does not yet provide the necessary diffusion stability and texture properties. Therefore, a further step follows in which the temperature of the microcapsule dispersion is raised to approximately 60 °C, which leads to crosslinking of the polymers in the wall and the curing of the capsules. A corresponding process is known, for example, from EP 2 111 214 B1 (GIVAUDAN).

[0014] From DE 23 03 866 A1 (FUJI) a stable concentrated mixture for the production of microcapsules is known which contains (a) an epoxypropyltrialkylammonium salt and additionally an alkyl sulfosuccinate which has alkyl groups with 6 to 16 carbon atoms, or an alkyl sulfosuccinamate whose carboxamide group is substituted with an alkyl group with 8 to 20 carbon atoms, and a water-miscible solvent as component (b).

[0015] EP 2 669 835 A1 (KOEHLER) relates to a process for producing microcapsules. These microcapsules are characterized by a specific particle size distribution exhibiting at least two maxima, the main particle size maximum being in the range from 5 to 100 µm, and the volume occupied by the microcapsules whose particle size is less than or equal to a quarter of the particle size of the main maximum being greater than or equal to approximately 20% of the total volume of the microcapsules. The capsule wall can consist of a methylated melamine-formaldehyde resin and / or urea-formaldehyde resin and / or reaction products of aldehydes with thiourea, N-alkylurea, guanidine, acetoguanamine, benzoguanamine, caprionoguanamine, cyanamine, dicyandiamide, and / or alkyl / arylsulfonamide.

[0016] EP 3 238 816 A1 (SYMRISE) discloses a process for producing microcapsules, in particular aminoplast microcapsules, in which the emulsification of the aqueous pre-polymer phase and the non-aqueous phase containing the active ingredient to be encapsulated takes place in the presence of at least one 1,2-diol, which leads to a significant reduction in the microcapsule particle size and thus to a stabilization of the emulsion.

[0017] WO 2017 / 148504 (SYMRISE) relates to a process for producing fragrance capsules, in which a fragrance composition having an acid number of not more than 5 mg KOH / g immediately before encapsulation is encapsulated with natural coating materials or synthetic, anionic or cationic polymers or mixtures thereof.

[0018] US 2017 / 252274 A1 discloses a process for producing microcapsules, comprising the following steps: providing an oil phase comprising a polyisocyanate and a fragrance oil; providing an aqueous phase comprising a surfactant; preparing an oil-in-water emulsion; crosslinking by adding a mixture of crosslinking agents selected from a list comprising ethylenediamine and L-lysine monohydrochloride; and curing the microcapsules. A catalyst is used in the process. The surfactant can be polyvinyl alcohol. The fragrance of D1 can be an aliphatic carboxylic acid or an ester thereof, or an acyclic or cyclic terpene aldehyde. The microcapsules are used for the production of, for example, body washes.

[0019] Microcapsules can also be made from acrylate monomers, polyureas, or even biopolymers such as gelatin and other proteins or inorganic wall materials. State-of-the-art isocyanate-based microcapsules are produced by reacting polyisocyanates with guanidinium carbonate as a crosslinker in an alkaline environment.

[0020] The advantage of encapsulation with isocyanates compared to aminoplast resins is that the microcapsules are formaldehyde-free. The disadvantage of encapsulation with isocyanates and other wall materials, however, is that only a limited number of active ingredients, for example fragrances or fragrance oils, can be encapsulated and stable microcapsules can be produced. In particular, encapsulation with isocyanates and other wall materials is not suitable for the encapsulation of fragrances or fragrance oils with aldehyde, carboxylic acid or ester functionalities. During encapsulation at an alkaline pH value, carboxylic acids are deprotonated, oxidized aldehydes (carboxylic acids) are similarly saponified, and esters are saponified, making the resulting emulsion unstable. The use of this type of microencapsulation is therefore limited in terms of the active ingredients and is therefore only suitable for a narrow spectrum of fragrances or fragrance oils, for example.Fragrance oils are suitable, while such microencapsulation is not suitable for fragrances or fragrance oils with aldehyde, carboxylic acid, or ester functionalities. However, fragrances with aldehyde, carboxylic acid, or ester functionalities are among the most important representatives of fragrances and fragrance oils.

[0021] Against this background, the present invention was based on the complex task of providing a process for the production of microcapsules which, on the one hand, enables formaldehyde-free encapsulation for a wide variability with regard to the active ingredients to be encapsulated, in particular active ingredients with aldehyde, carboxylic acid or ester functionalities, and, on the other hand, produces microcapsules which are storage-stable and have excellent release behavior of the active ingredients.

[0022] Surprisingly, it was discovered that this problem can be solved by producing the capsule shell or capsule wall, primarily formed from isocyanates, in an aqueous emulsion in the presence of a protective colloid and a catalyst through two consecutive crosslinking steps, each with an amine, at different pH values. Two-stage crosslinking at a pH gradient from acidic to alkaline makes it possible to form a multilayer capsule shell or capsule wall, which even allows the encapsulation of active ingredients, such as fragrances, with aldehyde, carboxylic acid, or ester functionalities.

[0023] The process-related advantage is that by crosslinking with a first crosslinker at an acidic pH value, the functional groups of the active ingredients to be encapsulated are protected by a first polymer layer before the pH value is raised by adding another, alkaline crosslinker. Summary of the invention

[0024] A first aspect of the invention therefore relates to a process for producing isocyanate-based or isothiocyanate-based microcapsules, which comprises or consists of the following steps: (a) providing an internal non-aqueous phase comprising at least one isocyanate having two or more isocyanate groups or at least one isothiocyanate having two or more isothiocyanate groups and a hydrophobic active ingredient to be encapsulated which has an aldehyde, carboxylic acid or ester functionality;(b) Providing an external aqueous phase comprising at least one protective colloid and a catalyst, 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, in particular 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, in particular 1,3,5-trihydroxybenzene, starch or chemically, mechanically and / or enzymatically modified starch, carboxymethylcellulose and polyvinylpyrrolidone as well as mixtures of the aforementioned compounds;(c) mixing the internal non-aqueous phase and the external aqueous phase, optionally in the presence of a stabilizer and / or emulsifier, to obtain an oil-in-water emulsion; (d) initial crosslinking by adding an amine reacting at an acidic pH; (e) further crosslinking by adding an amine reacting at an alkaline pH to obtain microcapsules; (f) curing the microcapsules obtained in step (e); and optionally (g) separating the microcapsules from the reaction solution and optionally drying the microcapsules.

[0025] Another aspect of the present invention are microcapsules comprising or consisting of: a core comprising or consisting of at least one hydrophobic active ingredient having an aldehyde, carboxylic acid or ester functionality; and a capsule shell comprising an isocyanate having at least two or more isocyanate groups, which is crosslinked in the presence of a protective colloid and a catalyst in a first step by an amine reacting at an acidic pH and in a further step by an amine reacting at an alkaline pH, 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, in particular 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, in particular 1,3,5-trihydroxybenzene, starch or chemically, mechanically and / or enzymatically modified starch, carboxymethylcellulose and polyvinylpyrrolidone as well as mixtures of the aforementioned compounds, wherein the capsule shell comprises or consists of: a first layer of polyurethane and a second layer of polyurea, wherein a linear polyurea matrix is ​​formed upon crosslinking at an acidic pH and a spatially crosslinked polyurea matrix is ​​formed upon crosslinking at an alkaline pH.

[0026] Finally, in a further aspect, the present invention relates to the use of the microcapsules according to the invention or of suspensions comprising the microcapsules according to the invention for the production of detergents, fabric softeners, cleaning agents, scent boosters, cosmetics, personal care products, agricultural products or pharmaceutical products.

[0027] These and other aspects, features, and advantages of the present invention will become apparent to those skilled in the art from a study of the following detailed description and claims. Any feature of one aspect of the invention may be substituted or substituted for another aspect of the invention. Furthermore, it is to be understood that the examples contained herein describe and illustrate the invention, but are not intended to limit it, and in particular, the present invention is not limited to these examples.

[0028] All percentages are by weight unless otherwise stated. Numerical examples given in the form "from x to y" include the stated values. Where multiple preferred numerical ranges are given in this format, it is understood that any ranges resulting from the combination of the various endpoints are also included. Figures

[0029] Figure 1 This is a light micrograph of the microcapsules according to the invention at 10x magnification. An Olympus BX51 was used for the light micrograph. Figure 2 is a diagram showing the particle size distribution (d(0.5) value) of microcapsules according to the invention containing various perfume oils. Figure 3 is a diagram showing the particle size distribution (d(0.5) value) of state-of-the-art microcapsules containing different perfume oils. Figure 4is a diagram showing the zeta potential of microcapsules according to the invention containing perfume oil 4 or 5. Figure 5 is a diagram showing the zeta potential of state-of-the-art microcapsules containing perfume oil 1 or 2. Figure 6 is a diagram showing the results of a sensory evaluation of microcapsules of the prior art and microcapsules according to the invention. Detailed description of the invention

[0030] In a first aspect, the present invention relates to a process for producing isocyanate-based or isothiocyanate-based microcapsules, which comprises or consists of the following steps: (a) providing an internal non-aqueous phase comprising at least one isocyanate having two or more isocyanate groups or at least one isothiocyanate having two or more isothiocyanate groups and a hydrophobic active ingredient to be encapsulated which has an aldehyde, carboxylic acid or ester functionality;(b) Providing an external aqueous phase comprising at least one protective colloid and a catalyst, 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, in particular 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, in particular 1,3,5-trihydroxybenzene, starch or chemically, mechanically and / or enzymatically modified starch, carboxymethylcellulose and polyvinylpyrrolidone as well as mixtures of the aforementioned compounds;(c) mixing the internal non-aqueous phase and the external aqueous phase, optionally in the presence of a stabilizer and / or emulsifier, to obtain an oil-in-water emulsion; (d) initial crosslinking by adding an amine reacting at an acidic pH; (e) further crosslinking by adding an amine reacting at an alkaline pH to obtain microcapsules; (f) curing the microcapsules obtained in step (e); and optionally (g) separating the microcapsules from the reaction solution and optionally drying the microcapsules.

[0031] In the context of the present invention, microcapsules are understood to mean microparticles which have a capsule shell or capsule wall and one or more hydrophobic active ingredients as core material inside the capsule.

[0032] In a first step of the process according to the invention, an internal non-aqueous phase is provided which comprises at least one isocyanate having at least two or more isocyanate groups and a hydrophobic active ingredient to be encapsulated.

[0033] The polymerizable isocyanate compounds or isocyanate monomers usable according to the invention for forming the capsule shell or capsule wall are isocyanates or isothiocyanates with at least two, three, four, or higher-functional isocyanate groups or isothiocyanate groups, in particular aliphatic, cycloaliphatic, hydroaromatic, aromatic, or heterocyclic polyisocyanates or polyisothiocyanates, their substitution products, and mixtures of the aforementioned compounds. Among the polyisocyanates, diisocyanates are preferred. Aromatic diisocyanates are even more preferred.

[0034] By using mixtures of different polymerizable compounds containing at least two isocyanate or isothiocyanate groups, copolymers can also be prepared.

[0035] Examples of the monomers containing at least two isocyanate groups or at least two isothiocyanate groups which can be used according to the invention 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-tolylene diisocyanate, 2,6-tolylene 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.

[0036] Industrially produced di- and polyisocyanates are preferred as polymerizable compounds containing at least two isocyanate or isothiocyanate groups, for example TDI: tolylene diisocyanate (isomer mixture of 2,4- and 2,6-tolylene diisocyanate in a ratio of 80:20), HDI: hexamethylene diisocyanate-(1,6), IPDI: isophorone diisocyanate or DMDI: diphenylmethane-4,4'-diisocyanate.

[0037] Other starting isocyanates used in the process according to the invention are: diisocyanates such as 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- and 2,4,4-trimethyl-1,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3- and 1,4-diisocyanatocyclohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate), 4,4'-diisocyanatodicyclohexylmethane, 2,4- and 2,6-diisocyanatomethylcyclohexane, and mixtures thereof. In principle, aromatic isocyanates, e.g., tolylene diisocyanates or 4,4'-diisocyanatodiphenylmethane, can also be used.

[0038] Polyisocyanates which can be prepared by modifying the above-mentioned diisocyanates or mixtures thereof by known processes and which contain, for example, uretdione, urethane, isocyanurate, biuret and / or allophanate groups can also be used proportionally.

[0039] The proportion of the isocyanate component in the internal non-aqueous phase is in a range of 1 to 8 wt.%, preferably in a range of 3 to 7 wt.%, based on the total weight of the non-aqueous phase. Most preferably, the isocyanate component in the internal non-aqueous phase is used in a range of 5 to 6 wt.%, based on the total weight of the non-aqueous phase.

[0040] The microcapsules according to the invention are designed in such a way that they have a core material made of at least one hydrophobic active ingredient, in particular a hydrophobic fragrance or a hydrophobic fragrance oil, a pesticide, a biocide, an insecticide, a substance from the group of repellents, food additives, cosmetic active ingredients, pharmaceutical active ingredients, dyes, agrochemicals, dyes, luminous colors, optical brighteners, solvents, waxes, silicone oils, lubricants, and mixtures of the aforementioned active ingredients, ie as long as it is sufficiently water-insoluble or does not mix with the water phase, since otherwise no emulsion can form and no deposition of the polymer on the droplet surface can take place.

[0041] In a preferred variant of the first aspect of the present invention, the active ingredients considered are, in particular, hydrophobic fragrances or fragrance oils, aromas or biogenic principles.

[0042] In a preferred embodiment, the microcapsules according to the invention have a core material in the form of a hydrophobic single fragrance or single odorant, wherein the core material comprises at least one single fragrance or single odorant or mixtures thereof, selected from one or more of the following groups: Hydrocarbons such as 3-carene; α-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; 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 ashexanal; 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; Aliphatic ketones and their oximes, such as B. 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; Aliphatic sulfur-containing compounds, such as 3-methylthiohexanol; 3-methylthiohexyl acetate; 3-mercaptohexanol; 3-mercaptohexyl acetate; 3-mercaptohexyl butyrate; 3-acetylthiohexyl acetate; 1-menthene-8-thiol; Aliphatic nitriles, such as 2-nonenonitrile; 2-tridecenonitrile; 2,12-tridecenonitrile; 3,7-Dimethyl-2,6-octadienonitrile; 3,7-Dimethyl-6-octenonitrile; Aliphatic carboxylic acids and their esters, such as(E)- und (Z)-3-Hexenylformiat; Ethylacetoacetat; Isoamylacetat; Hexylacetat; 3,5,5-Trimethylhexylacetat; 3-Methyl-2-butenylacetat; (E)-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; Acyclische Terpenalkohole, wie z. B.citronellol; geraniol; Nerol; linalool; lavadulol; nerolidol; farnesol; tetrahydrolinalool; tetrahydrogeraniol; 2,6-Dimethyl-7-octen-2-ol; 2,6-Dimethyloctan-2-ol; 2-Methyl-6-methylene-7-octen-2-ol; 2,6-Dimethyl-5,7-octadien-2-ol; 2,6-Dimethyl-3,5-octadien-2-ol; 3,7-Dimethyl-4,6-octadien-3-ol; 3,7-Dimethyl-1,5,7-octatrien-3-ol; 2,6-Dimethyl-2,5,7-octatrien-I-ol; as well as their formates, acetates, propionates, isobutyrates, butyrates, isovalerates, pentanoates, hexanoates, crotonates, tiglinates, 3-methyl-2-butenoates; acyclic terpene aldehydes and ketones, such as geranial; neral; citronellal; 7-hydroxy-3,7-dimethyloctanal; 7-methoxy-3,7-dimethyloctanal; 2,6,10-trimethyl-9-undecenal; geranylacetone; as well as the dimethyl and diethyl acetals of geranial, neral, 7-hydroxy-3,7-dimethyloctanal; cyclic terpene alcohols, such asMenthol; Isopulegol; α-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, pentanoates, hexanoates, crotonates, tiglinates, 3-methyl-2-butenoates; Cyclic terpene aldehydes and ketones, such as menthone; isomenthone; 8-mercaptomenthan-3-one; carvone; camphor; fenchone; α-ionone; beta-ionone; α-n-methylionone; beta-n-methylionone; α-isomethylionone; beta-Isomethylionone; α-Iron; ß-Iron; α-Damascenone; beta-Damascenone; gamma-Damascenone; d-Damascenone; 1-(2,4,4-Trimethyl-2-cyclohexen-1-yl)-2-buten-1-one; 1,3,4,6,7,8a-Hexahydro-1,1,5,5-tetramethyl-2H-2,4a-methanonaphthalen-8(5H)-one; Nootkatone; Dihydronootkatone; α-Sinensal; beta-Sinensal; acetylated cedarwood oil (methyl cedryl ketone); Cyclic alcohols, such as4-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-Trimethyl-cyclohexylmethanol; 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 z. B. Cineol; Cedrylmethylether; Cyclododecylmethylether; (Ethoxymethoxy)cyclododecan; α-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 Ketone, wie z. B. 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; 9-Cycloheptadecen-1-on; Cyclopentadecanon; Cyclohexadecanon; Cycloaliphatische Aldehyde, wie z. B. 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 z. B.1-(3,3-Dimethylcyclohexyl)-4-penten-1-one; 1-(5,5-Dimethyl-2-cyclohexen-1-yl)-4-penten-1-one; 2,3,8,8-tetramethyl-1,2,3,4,5,6,7,8-octahydro-2-naphthalenyl methyl ketone; Methyl 2,6,10-trimethyl-2,5,9-cyclododecatrienyl ketone; tert-Butyl-(2,4-dimethyl-3-cyclohexen-1-yl)ketone; Esters of cyclic alcohols, such as B. 2-tert-butylcyclohexyl acetate; 4-tert-butylcyclohexyl acetate; 2-tert-pentylcyclohexyl acetate; 4-tert-pentylcyclohexyl acetate; decahydro-2-naphthyl acetate; 3-Pentyltetrahydro-2H-pyran-4-yl acetate; decahydro-2,5,5,8a-tetramethyl-2-naphthyl acetate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5- or -6-indenyl acetate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5- or -6-indenylpropionate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5- or -6-indenylisobutyrate; 4,7-methanooctahydro-5- or -6-indenyl acetate; esters of cycloaliphatic carboxylic acids, such asAllyl 3-cyclohexylpropionate; allylcyclohexyloxyacetate; methyl dihydrojasmonate; methyl jasmonate; Methyl 2-hexyl-3-oxocyclopentane carboxylate; 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 B. styrene and diphenylmethane; Araliphatic alcohols, such as B. 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 araliphatic alcohols and aliphatic carboxylic acids, such asBenzylacetat; Benzylpropionat; Benzylisobutyrat; Benzylisovalerianat; 2-Phenylethylacetat; 2-Phenylethylpropionat; 2-Phenylethylisobutyrat; 2-Phenylethylisovalerianat; 1-Phenylethylacetat; α-Trichlormethylbenzylacetat; a,a-Dimethylphenylethylacetat; a,a-Dimethylphenylethylbutyrat; Cinnamylacetat; 2-Phenoxyethylisobutyrat; 4-Methoxybenzylacetat; Araliphatischen Ether, wie z. B. 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 z. B.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; a-Butylzimtaldehyd; a-Amylzimtaldehyd; a-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; Aromatische und araliphatische Ketone, wie z. B.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-indanyl methyl ketone; 6-tert-Butyl-1,1-dimethyl-4-indanylmethyl ketone; 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-acetonaphtone; Aromatic and araliphatic carboxylic acids and their esters, such asBenzoesäure; Phenylessigsäure; Methylbenzoat; Ethylbenzoat; Hexylbenzoat; Benzylbenzoat; Methylphenylacetat; Ethylphenylacetat; Geranylphenylacetat; Phenylethyl-phenylacetat; Methylcinnamat; Ethylcinnamat; Benzylcinnamat; Phenylethylcinnamat; Cinnamylcinnamat; Allylphenoxyacetat; Methylsalicylat; Isoamylsalicylat; Hexylsalicylat; Cyclohexylsalicylat; cis-3-Hexenylsalicylat; Benzylsalicylat; Phenylethylsalicylat; Methyl-2,4-dihydroxy-3,6-dimethylbenzoat; Ethyl-3-phenylglycidat; Ethyl-3-methyl-3-phenylglycidat; Stickstoffhaltige aromatische Verbindungen, wie z. B.2,4,6-trinitro-1,3-dimethyl-5-tert-butylbenzene; 3,5-dinitro-2,6-dimethyl-4-tert-butylacetophenone; cinnamic acid nitrile; 5-phenyl-3-methyl-2-pentenonitrile; 5-phenyl-3-methylpentanoonitrile; methyl anthranilate; Methy-N-methylanthranilate; 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 estragole; anethole; eugenol; eugenyl methyl ether; iso-eugenol; iso-eugenyl methyl ether; thymol; carvacrol; diphenyl ether; beta-naphthyl methyl ether; beta-naphthyl ethyl ether; beta-naphthyl isobutyl ether; 1,4-dimethoxybenzene; eugenyl acetate; 2-methoxy-4-methylphenol; 2-ethoxy-5-(1-propenyl)phenol; p-cresyl phenyl acetate; from the group of heterocyclic compounds such as2,5-Dimethyl-4-hydroxy-2H-furan-3-on; 2-Ethyl-4-hydroxy-5-methyl-2H-furan-3-on; 3-Hydroxy-2-methyl-4H-pyran-4-on; 2-Ethyl-3-hydroxy-4H-pyran-4-on; Lactone, wie z. B. 1,4-Octanolid; 3-Methyl-1,4-octanolid; 1,4-Nonanolid; 1,4-Decanolid; 8-Decen-1,4-olid; 1,4-Undecanolid; 1,4-Dodecanolid; 1,5-Decanolid; 1,5-Dodecanolid; 1,15-Pentadecanolid; cis- und trans-11-Pentadecen-1,15-olid; cis- und trans-12-Pentadecen-1,15-olid; 1,16-Hexadecanolid; 9-Hexadecen-1,16-olid, 10-Oxa-1,16-hexadecanolid; 11-Oxa-1,16-hexadecanolid; 12-Oxa-1,16-hexadecanolid; Ethylen-1,12-dodecandioat; Ethylen-1,13-tridecandioat; Cumarin; 2,3-Dihydrocumarin; Octahydrocumarin; . sowie die Stereoisomere, Enantiomere, Stellungsisomere, Diastereomere, cis / trans-Isomere bzw. Epimere der zuvor genannten Substanzen.

[0043] In an alternative embodiment, fragrance oils or perfume oils are used as the core material. These are compositions that contain at least one fragrance. Such compositions, in particular fragrance oils or perfume oils, preferably comprise two, three, four, five, six, seven, eight, nine, ten or more fragrances. The fragrance oils or perfume oils are preferably selected from the group of extracts from natural raw materials, such as essential oils, concretes, absolutes, resins, resinoids, balsams, tinctures such as, for example, ambergris tincture; amyris oil; angelica seed oil; angelica root oil; anise oil; valerian oil; basil oil; tree moss absolute; bay oil; mugwort oil; benzoresin; bergamot oil; beeswax absolute; birch tar oil; bitter almond oil; savory oil; bucco leaf oil; cabreuva oil; cade oil; calmus oil; camphor oil; cananga oil; cardamom oil; cascarilla oil; cassia oil; Cassie Absolu; Castoreum Absolü; cedar leaf oil; cedarwood oil; cistus oil; citronella oil; lemon oil; copaiva balm; copaiva 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; Pine 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 leaf oil; Mace oil; Marjoram oil; Mandarin oil; Massai bark 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; Olibanum absolute; Olibanum oil; Opoponax oil;Orange blossom absolute; orange oil; oregano oil; palmarosa oil; patchouli oil; perilla oil; Peru balsam oil; parsley leaf oil; parsley seed oil; petitgrain oil; peppermint oil; pepper oil; allspice 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 oil; hyssop oil; civet absolute; cinnamon leaf oil; Cinnamon bark oil; as well as fractions thereof or ingredients isolated therefrom.;

[0044] Of the aforementioned individual fragrances or individual odoriferous substances that can be encapsulated in the sense of the present invention, fragrances or odoriferous substances that have an aldehyde, carboxylic acid or ester functionality are used.

[0045] Aldehydic fragrances or odorants, which also include the corresponding acetals as well as 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; and their mixtures.

[0046] The aforementioned fragrances or odorants with aldehyde, carboxylic acid or ester functionality and 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-trimethylcyclohexen-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-indenylisobutyrate; 4,7-methanooctahydro-5- or -6-indenyl acetate; esters of araliphatic 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-cyclohexylpropionate; allylcyclohexyloxyacetate; 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 asMethylbenzoat; Ethylbenzoat; Hexylbenzoat; Benzylbenzoat; Methylphenylacetat; Ethylphenylacetat; Geranylphenylacetat; Phenylethylphenylacetat; Methylcinnamat; Ethylcinnamat; Benzylcinnamat; Phenylethylcinnamat; Cinnamylcinnamat; Allylphenoxyacetat; Methylsalicylat; Isoamylsalicylat; Hexylsalicylat; Cyclohexylsalicylat; cis-3-Hexenylsalicylat; Benzylsalicylat; Phenylethylsalicylat; Methyl-2,4-dihydroxy-3,6-dimethylbenzoat; Ethyl-3-phenylglycidat; Ethyl-3-methyl-3-phenylglycidat. .

[0047] Aldehydes, acetals, esters and lactones are listed below 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: Aldehydes: 2-methylpentanal; Aldehyde C12 MNA HM; Aldehydes C 4; Aldehydes C 5; Aldehydes C 6; Aldehydes C 7; Aldehydes C 8; Aldehydes C 9; Aldehydes C 10; Aldehydes C 11 ISO; Aldehydes C 11 MOA PURE; Aldehydes C 11 UNDECANAL; Aldehydes C 11 UNDEYLENIC; Aldehydes C 12; ; Aldehydes C 12 MNA; Aldehydes C 13; ALDEHYDE MADARINE; AMYL CINNAMIC ALDEHYDE ALPHA; ANISALALDEHYDE-O; ANISYL ALDEHYDES; BENZALDEHYDE NATURAL; 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; Acetals: FLOROPAL; HEPTANAL DIETHYL ACETAL; NONANDIENAL DIETHYL ACETAL; OKOUMAL; PHENYLACET ALD. GLYCERIN ACETAL; PHENYLACETALDEYHDEDIMETHYLACETAL; Ester: JASMAL; EVERY TIME; KHARISMAL; TIRAMISONE ®< .

[0048] In a further variant of the process according to the invention, flavorings can also be encapsulated as core material in the form of a single flavor, wherein the core material comprises at least one single flavoring or mixtures thereof.

[0049] Typical examples of flavors 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; butylidenephthalide; 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 as well as the stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers and epimers of these substances not explicitly mentioned here.

[0050] Most preferably, fragrances or flavorings are used in the production of the isocyanate-based microcapsules which are selected from the group consisting of: AGRUMEX LC; AGRUNITRIL; ALDEHYDE C11 UNDECYLENIC; ALDEHYDE C12 LAURIN; ALDEHYDE C12 MNA; ALDEHYDE C14 SOG; ALDEHYDE C16 SOG.; ALLYLAMYL GLYCOLATE; ALLYL CAPRONATE; ALLYL CYCLOHEXYL PROPIONATE; ALLYL HEPTYLATE; AMBROCENIDE ®< 10 TEC; AMBROCENIDE ®< Crystallized 10% IPM; AMBROXIDE; ANETHOL NAT. EX STAR ANISE; ANISALDEHYDE PURE; APRIFLOREN ®< ; BENZYL ACETONE; BENZYL SALICYLATE; BORNEOL L / ISOBORNEOL 65 / 35; BUCCOBLEA OIL; CITRONELLOL 950; CLONAL; CYCLOHEXYL SALICYLATE; CYMOL PARA SUPRA; DAMASCONE DELTA; DIHYDROMYRCENOL; DIMETHYLBENZYLCARBINYLBUTYRATE; DYNASCONE; ETHYLENE BRASSYLATE; ETHYLMETHYLBUTYRATE-2; ETHYLSAFRANATE; EUCALYPTOL NATURAL; EUCALYPTUS OIL GLOBULUS 80 / 85%; EUGENOL NATURAL; FARENAL ®< ; FENNEL OIL AROMA TYPE SWEET NATURAL; FILBERTONE 10% IPM; FILBERTONES; FLORAL OPAL; GALBASCONE; GERANIOL 60; GLOBANONE ®< ; HEDIONE; HERBAFLORATE; HERBANATE; HERBYL PROPIONATE; HEXENYL ACETATE CIS-3; HEXENYL SALICYLATE CIS-3; HEXYL ACETATE; HEXYL ACETATE S; HEXYLISOBUTYRATE; HEXYL SALICYLATE; ISOAMYLBUTYRATE; ISOBORNYL ACETATE; ISOPROPYLMETHYLBUTYRATE-2; ISORALDEIN 70; JAVANOL; FIGHTER DL; CRESOL METHYL ETHER P(CR<10 PPM); LEMONILE; LIGUSTRAL; LILY; LINALOOL; MANZANATE; MELONAL; METHYLHEPTIN CARBONATE; METHYLOCTIN CARBONATE; MUSCENONE; NEOCYCLOCITRAL; NEROLIN BROMELIA; NEROLIN YARA YARA KRIST.; NEROLIONE; NORLIMBANOL; ORANGE OIL; ORIVONE; OZONIL; PATCHOULI OIL DETAIL; VEGETABLE OIL TRIGLYCERIDE; PHELLANDRENE FRACTION EX EUCALYPTUS OIL; PHENIRATE ®< ; PHENYLETHYL ACETATE; ROSE OXIDE HIGH CIS; SANDRANOL ®< ; STYROLYL ACETATE; SULTANENE ®< ; TERPINENE GAMMA; TETRAHYDROLINALOOL; TIMBERSILK; TRIETHYLCITRATE; UNDECAVERTOL; VERTOCITRAL; VERTOFIX; YSAMBER ®< K and mixtures of the aforementioned active ingredients.

[0051] In a further variant of the method according to the invention, biogenic principles can also be encapsulated as core material, wherein the core material comprises at least one biogenic principle or mixtures thereof.

[0052] Biogenic principles are understood to mean active ingredients with biological activity, for example tocopherol, tocopherol acetate, tocopherol palmitate, ascorbic acid, carnotine, carnosine, caffeine, (deoxy)ribonucleic acid and its fragmentation products, β-glucans, retinol, bisabolol, allantoin, phytantriol, panthenol, AHA acids, amino acids, ceramides, pseudoceramides, essential oils, plant extracts, and vitamin complexes.

[0053] In the process according to the invention for producing isocyanate-based microcapsules, the above-described monomer containing at least two isocyanate or isothiocyanate groups is first dissolved in an inert solvent or solvent mixture together with the hydrophobic active ingredient to be encapsulated. The thus formed organic, hydrophobic, oily phase forms the internal non-aqueous phase.

[0054] Inert solvents for the internal non-aqueous phase include: chlorinated biphenyl, chlorinated paraffin, vegetable oils such as cottonseed oil, peanut oil, palm oil, tricresyl phosphate, silicone oil, dialkyl phthalates, dialkyl adipates, partially hydrogenated terphenyl, alkylated biphenyl, 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 oil triglycerides, benzyl benzoate, or isopropyl myristate are preferably used as solvents for providing the internal non-aqueous phase.

[0055] The internal non-aqueous phase may contain, for example, 20 to 50 wt.%, preferably 25 to 45 wt.% and even more preferably 33 to 40 wt.% of hydrophobic active ingredient to be encapsulated, 1 to 8 wt.%, preferably 3 to 7 wt.% and even more preferably 5 to 6 wt.% of isocyanate and, in addition, 100 wt.% of hydrophobic solvents, based on the total weight of the internal non-aqueous phase.

[0056] The internal non-aqueous phase, which comprises at least one isocyanate having two or more isocyanate groups and at least one hydrophobic active ingredient, is emulsified in an external aqueous or hydrophilic phase to form an oil-in-water emulsion.

[0057] The external aqueous phase comprises at least one protective colloid and at least one catalyst.

[0058] A protective colloid is a compound that prevents the primary particles from clumping together (agglomerating, aggregating, flocculating, or coagulating) during precipitation reactions—that is, reactions in which a solid phase is separated from a homogeneous liquid phase. The protective colloid attaches to the primary particles with its hydrophobic moiety and directs its polar, i.e., hydrophilic, molecular moiety toward the aqueous phase. Through this attachment to the interface, it lowers the interfacial tension and prevents the primary particles from agglomerating. It also stabilizes the emulsion, promoting the formation of comparatively smaller droplets and thus corresponding microcapsules.

[0059] The protective colloid used in the process according to the first aspect of the present invention 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, in particular triols, such as glycerol and its ethoxylation and propoxylation products, trimethylolpropane and its ethoxylation and propoxylation products, polyvinyl alcohol and its derivatives, such as ammonium- or sulfonate-functionalized polyvinyl alcohols, polyphenols, preferably 1,3,5-trihydroxybenzene, starch, in particular starch from wheat, potatoes, corn, rice, tapioca or oats, or chemically, mechanically and / or enzymatically modified starch, as well as mixtures of the aforementioned compounds.

[0060] Other protective colloids that can be added to the external aqueous phase to stabilize the emulsion are preferably carboxymethylcellulose or polyvinylpyrrolidone, which is commercially available, for example, under the name Luviskol ®<, as well as mixtures of the aforementioned compounds.

[0061] Polyols, polyphenols, or starch, especially modified starch, are most preferably used as protective colloids. Polyvinyl alcohol or its ammonium derivatives, 1,3,5-trihydroxybenzene, or modified starch are particularly preferably used as protective colloids for the production of the microcapsules according to the invention.

[0062] The aforementioned compounds have a dual function: on the one hand, they react with the isocyanate(s), forming stable microcapsules, and on the other hand, they act as a protective colloid by preventing the agglomeration of the solid particles, stabilizing the emulsion and thus promoting the formation of small droplets.

[0063] Surprisingly, it has proven particularly advantageous to use one of the aforementioned protective colloids in the external aqueous phase in combination with starch or modified starch as an additional protective colloid. Such a combination promotes a reaction between the protective colloid and the isocyanate(s).

[0064] The most preferred combination is a protective colloid with modified starch. The use of one of the aforementioned combinations has the advantage that the solid phase in the formulation cannot flocculate and the emulsion is stabilized. Furthermore, the combined use results in particularly stable microcapsules.

[0065] A particularly advantageous combination has been found to be a polyphenol, preferably 1,3,5-trihydroxybenzene, with starch or modified starch. A combination of 1,3,5-trihydroxybenzene with modified starch is most preferred.

[0066] 1,3,5-Trihydroxybenzene is used as a hydroxyl group donor; to provide corresponding groups in protective colloids without hydroxyl groups and thus ensure an increase in stability.

[0067] The amount of the protective colloid or the amount of a combination of protective colloids used is in a range of 1 to 8 wt.%, preferably in a range of 2 to 4 wt.%, more preferably in a range of 3 to 4 wt.%, based on the total weight of the external aqueous phase.

[0068] The ratio of protective colloid in the external aqueous phase to isocyanate or isothiocyanate in the internal non-aqueous phase is in a range of 1:5 to 1:100, preferably in a range of 1:10 to 1:75, even more preferably in a range of 1:25 to 1:50.

[0069] The catalyst used in the external aqueous phase of the process according to the invention is preferably diazobicyclo[2.2.2]octane (DABCO). DABCO, also called triethylenediamine (TEDA), is a bicyclic tertiary amine. DABCO is used as a catalyst for the production of polyurethane plastics. The tertiary amine with free electron pairs promotes the reaction between the isocyanate in the internal non-aqueous phase and the protective colloid in the external aqueous phase.

[0070] The amount of catalyst added to the external aqueous phase is in a range of 0.001 to 1 wt.%, preferably in a range of 0.02 to 0.75 wt.%, and particularly preferably in a range of 0.05 to 0.5 wt.%, based on the total weight of the external aqueous phase. However, if the polymerization proceeds slowly, the catalyst content can also be increased.

[0071] Emulsion formation (for liquid active ingredients) or suspension formation (for solid active ingredients), i.e., the emulsification or suspension of the internal non-aqueous or oily phase with the external aqueous or hydrophilic phase, occurs under high turbulence or strong shear, with the strength of the turbulence or shear determining the diameter of the resulting microcapsules. Microcapsules can be produced continuously or discontinuously. As the viscosity of the aqueous phase increases or the viscosity of the oily phase decreases, the size of the capsules generally decreases.

[0072] Surprisingly, it was found that upon emulsification or suspension of the internal non-aqueous phase in the external aqueous phase in the presence of the protective colloid, preferably a polyol, a capsule shell or capsule wall forms near the core at the interfaces of the emulsified or suspended hydrophobic particles to be encapsulated, which form the core of the microcapsule according to the invention, by interfacial polymerization. This formation is based on the polyaddition reaction of the polyisocyanate with the protective colloid, preferably a polyol, to form a capsule shell or capsule wall made of polyurethane according to the following formula: O=C=NRN=C=O + -(CH 2 -CH(OH)-) n - →-(RO-CO-NH-R-NH-CO-O-) n

[0073] This is evident through gas evolution and the release of carbon dioxide. It may be advantageous if, for the production of the isocyanate-based microcapsules according to the present invention, the external aqueous phase optionally contains further protective colloids and / or stabilizers and / or emulsifying aids, either dissolved or dispersed. Such agents can be added, for example, in amounts of 0.05 to 5 wt.%, preferably 0.1 to 4 wt.%, based on the total weight of the aqueous phase.

[0074] The external aqueous phase preferably also contains stabilizers that stabilize the emulsion / slurry to prevent demixing of the internal non-aqueous (oily) phase and the external aqueous phase. The preferred stabilizers for producing the isocyanate-based microcapsules according to the present invention are primarily acrylic copolymers containing sulfonate groups. Also suitable are copolymers of acrylamides and acrylic acid, copolymers of alkyl acrylates and N-vinylpyrrolidone, such as LUVISKOL® K15, K30, or K90 (BASF); sodium polycarboxylates, sodium polystyrenesulfonates, vinyl and methyl vinyl ether-maleic anhydride copolymers, as well as ethylene-, isobutylene-, or styrene-maleic anhydride copolymers; microcrystalline cellulose, which is sold, for example, under the name VIVAPUR®, diutan gum, xanthan gum, or carboxymethylcelluloses.

[0075] The amount of stabilizers used can be in the range from 0.01 to 10 wt.% and in particular in the range from 0.1 to 3 wt.%, in each case based on the external aqueous phase.

[0076] Optionally, emulsifiers, preferably O / W emulsifiers, are used in the process according to the invention. These enable a homogeneous distribution of the oil droplets of the internal non-aqueous phase in the external aqueous phase and stabilize the emulsion. The same applies to the mixing of solid, insoluble active ingredients in the external aqueous phase to stabilize the resulting suspension.

[0077] Suitable emulsifiers include, for example, non-ionic 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 with linear fatty alcohols having 8 to 22 C atoms, with fatty acids having 12 to 22 C atoms, with alkylphenols having 8 to 15 C atoms in the alkyl group and alkylamines having 8 to 22 carbon atoms in the alkyl radical; alkyl and / or alkenyl oligoglycosides having 8 to 22 carbon atoms in the alk(en)yl radical and their ethoxylated analogues; addition products of 1 to 15 mol of ethylene oxide with castor oil and / or hydrogenated castor oil; addition products of 15 to 60 mol of ethylene oxide with castor oil and / or hydrogenated castor oil; Partial esters of glycerol and / or sorbitan with unsaturated, linear or saturated, branched fatty acids having 12 to 22 carbon atoms and / or hydroxycarboxylic acids having 3 to 18 carbon atoms and their adducts with 1 to 30 moles of ethylene oxide;Partial esters of polyglycerol (average degree of self-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 having 12 to 22 carbon atoms and / or hydroxycarboxylic acids having 3 to 18 carbon atoms and 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 having 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 dipolyhydroxystearates; polymer emulsifiers, e.g., Pemulen types (TR-1, TR-2) from Goodrich or Cosmedia®< SP from Cognis; polyalkylene glycols and glycerol carbonate.

[0078] Typical anionic emulsifiers that can be used in the process according to the invention for producing the isocyanate-based microcapsules are aliphatic fatty acids having 12 to 22 carbon atoms, such as palmitic acid, stearic acid or behenic acid, and dicarboxylic acids having 12 to 22 carbon atoms, such as azelaic acid or sebacic acid.

[0079] Furthermore, zwitterionic surfactants can be used as emulsifiers in the process according to the invention for producing the isocyanate-based microcapsules. Zwitterionic surfactants are surface-active compounds that contain at least one quaternary ammonium group and at least one carboxylate and one sulfonate group in the molecule. Particularly suitable zwitterionic surfactants are the so-called betaines, such as 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 containing 8 to 18 carbon atoms in the alkyl or acyl group, as well as cocoacylaminoethylhydroxyethylcarboxymethylglycinate. The fatty acid amide derivative known by the CTFA name Cocamidopropyl Betaine is particularly preferred.Ampholytic surfactants are also suitable emulsifiers. Ampholytic surfactants are surface-active compounds that, in addition to a C8 / 18 alkyl or acyl group, contain at least one free amino group and at least one -COOH or -SO3H group in the molecule and are capable of forming inner salts. Examples of suitable ampholytic surfactants are 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-cocoalkylaminopropionate, cocoacylaminoethylaminopropionate and C12 / 18 acylsarcosine.Finally, cationic surfactants can also be considered as emulsifiers, with those of the esterquat type, preferably methylquaternized difatty acid triethanolamine ester salts, being particularly preferred.

[0080] The emulsifiers may 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.%, each based on the total weight of the external aqueous phase.

[0081] The process according to the invention for producing the microcapsule dispersion can be carried out, for example, using the "inline" technique. In this process, the internal non-aqueous phase and the external aqueous phase are first fed separately to an emulsifying turbine by means of a forced-feed pump, then combined shortly before entering the emulsifying turbine or combined in the emulsifying turbine, at a flow rate of 1200 to 1500 l / h.

[0082] The weight ratio of internal non-aqueous phase to external aqueous phase is preferably in a range of 10:90 to 60:40, preferably in a range of 30:70 to 50:50.

[0083] Furthermore, the process according to the invention for producing the isocyanate-based microcapsules can also be carried out in conventional dispersion apparatuses or emulsifying devices.

[0084] The process of emulsification or suspension in the method according to the invention is advantageously carried out for a time of 0.5 to 10 minutes, preferably from 0.75 to 4 minutes and most preferably from 1 to 2.5 minutes, until a capsule size of 10 to 50 µm ± 5 µm has been established.

[0085] In a subsequent step of the process according to the invention, a first crosslinking of the capsule shell or capsule wall material is carried out, also while stirring at a stirring speed of 1000 to 1500 rpm, preferably at a stirring speed of 1200 rpm. The first crosslinking is carried out by adding an amine that reacts at an acidic pH to crosslink and stabilize the capsule shell enclosing the core material.

[0086] Particularly advantageous results for capsule shell formation are achieved when the first crosslinking with the amine takes place at an acidic pH of 2 to 7, preferably at a pH of 2 to 6 and most preferably at a slightly acidic pH of 3 to 5. For this purpose, an acid, for example formic acid or acetic acid, is added to the external aqueous phase and a pH in the above-mentioned ranges is adjusted.

[0087] Carrying out the first crosslinking in an acidic pH range has the advantage over crosslinking in a basic environment that the hydrophobic active ingredients with aldehyde, carboxylic acid or ester functionalities do not saponify during the first reaction steps of crosslinking the isocyanate or isothiocyanate.

[0088] This prevents the active ingredient or ingredients to be encapsulated, for example a perfume oil, from being chemically altered, which would result in a loss of the active ingredients and, on the other hand, the emulsion becoming unstable.

[0089] Even more preferably, the first crosslinking step is carried out at a temperature of 20 °C to 30 °C.

[0090] The amine reacting at an acidic pH is selected from the group consisting of basic amino acids and their hydrochlorides, especially lysine hydrochloride or ornithine hydrochloride. Lysine hydrochloride is most preferred as a crosslinking agent.

[0091] The first crosslinking agent is added to the emulsion either as such, for example as a solid, or in the form of an aqueous solution.

[0092] The first crosslinking agent is present in the aqueous solution at a concentration of 0.5 to 2 mol / l, preferably 1 mol / l. The solution has a pH of 4 to 7.

[0093] The first crosslinking in the process of the invention is carried out for a period of time of about 10 minutes to 20 minutes, preferably for a period of time of 12 to 18 minutes, and most preferably for a period of time of about 15 minutes.

[0094] The first crosslinking step is followed by a further crosslinking step of the material of the capsule shell or capsule wall by adding an amine that reacts at an alkaline pH to form a polyurea matrix.

[0095] Particularly advantageous results for capsule formation were achieved when further crosslinking with the alkaline pH-reactive amine was carried out at an alkaline pH of 7 to 14, preferably at an alkaline pH of 7 to 10 and most preferably at an alkaline pH of 7 to 8.

[0096] Even more preferably, the further crosslinking step is carried out at a temperature of 35 °C to 50 °C.

[0097] The amine reacting at an alkaline pH is selected from the group consisting of di-, tri-, and polyamines and guanidinium carbonate. Guanidinium carbonate is most preferred as an additional crosslinking agent.

[0098] The further crosslinking agent is added to the emulsion either as such, for example as a solid, or in the form of an aqueous solution.

[0099] The additional crosslinking agent is present in the aqueous solution at a concentration of 0.5 to 2 mol / l, preferably 1 mol / l. The solution has a pH of 7 to 14, preferably a pH of 12.

[0100] By adding the amine, which reacts at an alkaline pH, the pH of the emulsion is shifted to higher pH values. The pH of the final product, i.e., the final capsule slurry, is between 5 and 8, preferably between 6 and 7.

[0101] An essential feature of the production of isocyanate-based microcapsules according to the present invention is thus that the first crosslinking is carried out at an acidic pH and the subsequent further crosslinking is carried out at an alkaline pH.

[0102] Due to the pH gradient, a capsule shell with a linear polyurea matrix is ​​initially formed during the initial crosslinking, preferably at an acidic pH. During subsequent crosslinking, preferably at a basic pH, the capsule shell is further crosslinked, forming a spatially crosslinked polyurea matrix.

[0103] During the two cross-linking steps, the stirring power is reduced, for example to a stirring speed of about 800 to 1200 rpm, in order not to immediately break up the forming microcapsules.

[0104] After complete crosslinking and formation of the capsule shell or capsule wall, the capsules produced by the process according to the invention are present as raw microcapsules in the form of an aqueous dispersion or slurry.

[0105] After crosslinking, the microcapsules in the slurry still have a flexible shell that lacks particular stability and therefore breaks easily. For this purpose, the shell is cured. Curing is triggered by a temperature change, which is achieved by gradually raising the slurry temperature to a temperature of 70 °C, preferably to a temperature in the range of 60 to 65 °C. Curing is typically carried out over a period of 2 to 4 hours.

[0106] It is also advantageous to add hardening substances to the external aqueous phase. For this purpose, natural plant tannins of the tannin type are used. These are chemically proanthocyanidins, such as those found in dicotyledonous perennials, shrubs, and leaves, particularly in the tropics and subtropics. The terpenes generally have molecular weights in the range of 500 to 3,000 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 raw microcapsules. The tannins are usually added in amounts of about 0.1 to about 2 wt.%, and preferably from about 0.5 to about 1.5 wt.%, based on the microcapsules.

[0107] An important criterion for the usability of microcapsules is the weight ratio of core material to capsule wall material. While the highest possible proportion of core material is desired to ensure the highest possible utility of the capsules, it is also necessary that the capsules still contain a sufficient proportion of capsule wall material to ensure their stability.

[0108] According to the invention, it has proven particularly advantageous that the microcapsules are designed such that the microcapsules have a weight ratio of core material to capsule wall material which is 50:50 to 90:10, preferably 70:30 to 80:20.

[0109] After curing, the microcapsules produced by the process according to the invention are present as a dispersion in water, also referred to as a microcapsule dispersion. In this form, the microcapsules are generally ready for sale; however, for preservation purposes, it is recommended to dry them.

[0110] In principle, processes such as lyophilization are suitable for this purpose, but spray drying, for example in a fluidized bed, is preferred. It has proven advantageous to add additional polysaccharides, preferably dextrins and especially maltodextrins, to the dispersion at temperatures of approximately 20 to approximately 50 °C, and preferably approximately 40 °C, to assist 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.

[0111] The spray drying itself can be carried out continuously or batchwise in conventional spray systems, wherein the inlet temperature is about 170 to about 200 °C and preferably about 180 to 185 °C and the outlet temperature is about 70 to about 80 °C and preferably about 72 to 78 °C.

[0112] It has been shown that the process according to the invention enables the encapsulation of hydrophobic active ingredients, particularly hydrophobic active ingredients with aldehyde, carboxylic acid, or ester functionality. The microcapsules are characterized by excellent stability and release capacity.

[0113] Surprisingly, it has been found that the process according to the invention can also be used to produce microcapsules with a reduced amount of capsule shell or capsule wall material by up to 50%, without any impairment or 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 substance isocyanate while maintaining the same amount of active ingredient to be encapsulated.

[0114] In addition, the microcapsules produced by the process according to the invention are formaldehyde-free.

[0115] In a further aspect, the present invention relates to microcapsules produced by the process according to the invention.

[0116] As can be seen from the following data, stable microcapsules are formed upon emulsification in the presence of a protective colloid and a catalyst, and a two-stage crosslinking of the isocyanate-based shell material with an amine that reacts at an acidic pH and an amine that reacts at an alkaline pH. In particular, stable microcapsules are formed with a core material that contains a high proportion of active ingredients with aldehyde, carboxylic acid, or ester functionality.

[0117] The microcapsules according to the invention are Figure 1 illustrated at 10x magnification. The structure of the capsule shell can be observed by light microscopy. While oil droplets are visible at the beginning of the manufacturing process, dented microcapsules can be seen after cross-linking, heating, and cooling.

[0118] The microcapsules produced by the process according to the invention can be characterized by the following parameters of their size distribution: d(0.1) value: 10% of the capsules are smaller than this value; d(0.5) value: 50% of the capsules are larger, 50% of the capsules are smaller than this value; and d(0.9) value: 10% of the capsules are larger than this value.

[0119] To determine the particle size, the microcapsules according to the invention are dispersed in water in a dynamic process, and then the particle size is determined using laser diffraction. Depending on the size of the capsule, the laser beam is refracted differently and can thus be converted into a size. Mie theory was used for this purpose. A MALVERN Mastersizer 3000 was used for particle measurement.

[0120] The microcapsules according to the invention are characterized in that they have a particle size distribution with a d(0.5) value of 10 - 50 µm, preferably a d(0.5) value of 20 to 30 µm, as described in Figure 2 and have a particle size distribution with a d(0.9) value of 10 to 120 µm, preferably a d(0.9) value of 60 to 90 µm.

[0121] Figure 3 shows the particle size distribution (d(0.5) value) of microcapsules produced using state-of-the-art technology. For perfume oils 4 and 5, it is noticeable that size adjustment was not possible.

[0122] The microcapsules produced by the process according to the invention are further characterized in that they have a zeta potential which is characteristic for the microcapsules according to the invention at - 5 to - 15 mV, as shown in the Figures 4 and 5The zeta potential is preferably -10 mV. Each microcapsule has a zeta potential. The zeta potential is independent of the active ingredient to be encapsulated, in particular the perfume oil, but nevertheless depends on the polymer of the capsule shell. Due to the change in the zeta potential during the production of the microcapsules according to the invention, it is possible to demonstrate that a new polymer or shell has formed, since the surface and thus also the surface charge (zeta potential) of the particles in the emulsion changes. The microcapsules according to the invention, which are produced without a catalyst, have a zeta potential of -27 mV. State-of-the-art microcapsules have a zeta potential of ±0 mV. The Smoluchowski theory was applied in the measurements. A MALVERN Zetasizer nanoZS was used to measure the zeta potential.

[0123] Regardless of the signal intensity resulting from the dosage of the microcapsules in the dispersion medium, Figures 4 and 5 It is clearly evident that the zeta potential for the microcapsules according to the invention is between -5 and 0 mV, since the use of the catalyst and the associated acceleration of the polyurethane formation reaction is characteristic of the deviating zeta potential of -27 mV.

[0124] A further aspect of the present invention are therefore microcapsules which comprise or consist of: a core comprising or consisting of at least one hydrophobic active ingredient having an aldehyde, carboxylic acid or ester functionality; and a capsule shell comprising an isocyanate having two or more isocyanate groups, which is crosslinked in the presence of a protective colloid and a catalyst in a first step by an amine reacting at an acidic pH and in a further step by an amine reacting at an alkaline pH, 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, in particular 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, in particular 1,3,5-trihydroxybenzene, starch or chemically, mechanically and / or enzymatically modified starch, carboxymethylcellulose and polyvinylpyrrolidone as well as mixtures of the aforementioned compounds, wherein the capsule shell comprises or consists of: a first layer of polyurethane and a second layer of polyurea, wherein a linear polyurea matrix is ​​formed upon crosslinking at an acidic pH and a spatially crosslinked polyurea matrix is ​​formed upon crosslinking at an alkaline pH.

[0125] Surprisingly, it was found that the microcapsules produced by the process according to the invention have a layered shell structure or multilayer capsule shell or capsule wall, which is formed from a first layer of polyurethane near the core of the microcapsule and from a second layer of polyurea at the outer edge of the microcapsule.

[0126] The present invention relates to

[0127] Isocyanate-based microcapsules, characterized in that the capsule shell comprises or consists of: a first layer of polyurethane and a second layer of polyurea.

[0128] Due to the excellent stability and release capacity of the microcapsules and the possibility of encapsulating a broad spectrum of hydrophobic active ingredients with the microcapsules according to the invention, the isocyanate-based microcapsules according to the present invention can be used for a wide range of applications for fragrance and aromatization.

[0129] The present invention therefore ultimately relates, in a further aspect, to the use of the microcapsules according to the invention or of suspensions comprising the microcapsules according to the invention for the production of detergents, fabric softeners, cleaning agents, scent boosters in liquid or solid form, cosmetics, personal care products, agricultural products or pharmaceutical products.

[0130] A particularly suitable form of use for the microcapsules according to the invention is to admix them in the form of a suspension with the final product. Therefore, the present invention also relates to a suspension of the above-described microcapsules in a liquid, in particular in water. Such a suspension has particularly advantageous properties if it is designed such that the weight fraction of the microcapsules is approximately 20 to 60 wt.%, in particular approximately 25 to 50 wt.%, more preferably approximately 30 to 35 wt.%.

[0131] To prevent demixing 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. To achieve the desired viscosity of the suspension, a thickener is preferably used.

[0132] The microcapsules according to the invention are particularly suitable for enclosing hydrophobic fragrances or flavorings, which can then be used in various cleaning products.

[0133] The present invention therefore also relates in particular to the use of the described microcapsules as a component of detergents, in particular liquid detergents, fabric softeners, cleaning agents, scent boosters in liquid or solid form, cosmetics, personal care products, in particular shower gels, shampoos, deodorants and / or body lotions.

[0134] The proportion of microcapsules in the aforementioned products is 0.05 to 15 wt.%, based on the total weight of the product, preferably 0.2 to 5 wt.%. Examples of implementation

[0135] The microcapsules of the present invention and their advantageous properties are described in more detail in the following examples.

[0136] The stability tests listed below were carried out at 50 °C.

[0137] Example 1: Stability data of microcapsules produced by the process of the invention, with and without catalyst (DABCO), a first crosslinker (lysine hydrochloride) at 20 to 30 °C, and a second crosslinker (guanidinium carbonate) at 35 to 50 °C. Polyvinyl alcohol was used as the protective colloid.

[0138] The stability test was conducted using a representative softener (fabric softener) into which the microcapsules were incorporated at a concentration of 1 wt.%. The softener was then stored for the periods listed below.

[0139] The capsule contents were analyzed using GC / MS (gas chromatography and mass spectrometry). The perfume oil content in the capsules was determined by comparison with a standard. A result of 64%, for example, means that 36% of the original amount of perfume oil is no longer in the capsule. Table 1 Perfume oil 3 days without catalyst 10 days without a catalyst 3 days with catalyst 10 days with catalyst Perfume oil 1 TomCap (20% substance) 64 % 57 % 70 % 61% Perfume oil 2 November 15 (15% substance) 71 % 63 % 73 % 64% Perfume Oil 3 Extreme Power Safe (25% substance) 81 % 73 % 91 % 85% Perfume Oil 4 Wonderball (30% substance) 29 % - 77 % 69 % Perfume Oil 5 High Ball (50% substance) 10 % - 86 % 78 % Perfume Oil 6 King of Cool (45% substance) 21 % - 63 % 49 % Note: Substance: Proportion of aldehyde, carboxylic acid, ester, primary alcohol components in the perfume oil composition

[0140] Perfume oils 4 to 6 are characterized by a high proportion of components with ester, aldehyde, and carboxylic acid functionality. The process according to the invention also yields excellent stability data for such perfume oils.

[0141] Example 2:Stability data of microcapsules produced by the process according to the invention with different protective colloids: crosslinking with lysine hydrochloride at a pH of 5.0; encapsulated oil: CARENE DELTA-3 NAT., CARYOPHYLLENE NAT. RECT., PHELLANDRENE L, PINENE ALPHA LAEVO NAT., TERPINENE GAMMA, VERDORACINE. Table 2 protective colloid 3 days 10 days Polyvinyl alcohol 83 % 72 % Cationic ammonium derivative of PVOH 69 % 54 % Strength 80 % 75 %

[0142] All microcapsules exhibit excellent stability data. When using the ammonium derivative of PVOH, stability is somewhat lower, due to the reduced number of hydroxyl groups.

[0143] Example 3: Using perfume oil 4 as an example, a shell reduction was performed. The monomer (isocyanate) content in the internal non-aqueous phase was reduced. Table 3 Monomer to oil ratio 3 days 10 days 1 : 20 77 % 69 % 1 : 30 78 % 70 % 1 : 33 70 % 62 % 1 : 35 66 % 58 % 1 : 40 70 % 59 % Note: A ratio of 1 : 20 means that 5 g of monomer was used to encapsulate 100 g of perfume oil

[0144] Capsules with a residual oil content of > 40% after 10 days are considered stable; in this case, the shell can be reduced by 50%.

[0145] Example 4: Comparison of the stability of microcapsules produced using the state-of-the-art encapsulation technology and the process according to the invention. The microcapsules were prepared as follows:

[0146] State-of-the-art encapsulation technology: Crosslinking: exclusively polyurea network; catalyst: none; protective colloid: polyvinyl alcohol; pH: 9.

[0147] Inventive process: non-aqueous phase consisting of two isocyanates dissolved in the perfume oil plus solvent; aqueous phase consisting of polyvinyl alcohol and DABCO; emulsification process: addition of lysine hydrochloride, which reacts in the acidic pH range (pH: 4 to 7); addition of guanidinum carbonate, which reacts in the alkaline pH range (pH: 7 to 14); pH of the final capsule slurry: 5 to 8. Table 4 Perfume oil 3 days of state-of-the-art technology 10 days of technology state of the art 3 days technology according to the invention 10 days technology according to the invention Perfume oil 1 TomCap (20% substance) 77 % 70 % 70 % 61% Perfume oil 2 November 15 (15% substance) 90 % 85 % 73 % 64% Perfume Oil 3 Extreme Power Safe (25% substance) 94 % 92 % 91 % 85% Perfume Oil 4 Wonderball (30% substance) 48 % 28 % 77 % 69 % Perfume Oil 5 High Ball (50% substance) 20 % - 86 % 78 % Perfume Oil 6 King of Cool (45% substance) 35 % 30 % 63% 49% Note: Substance: Proportion of aldehyde, carboxylic acid, ester, primary alcohol components in the perfume oil composition

[0148] Compared to the prior art encapsulation technology, the encapsulation technology according to the invention is universally applicable, whereas the prior art technology exhibits a significant decline in stability for perfume oils with a high proportion of components with ester, aldehyde, and carboxylic acid functionality. The encapsulation technology according to the invention exhibits gains in stability, particularly for perfume oils 4 to 6, while the stability is slightly lower for perfume oils 1 to 3. Example 5: Formation of a multilayer capsule shell

[0149] Table 5 protective colloid 3 days 50°C 10 days 50°C State of the art capsule 77 % 70 % Inventive capsule with PVOH 70 % 61% Inventive capsule with ammonium derivative of PVOH 41% 33% Inventive capsule with ammonium derivative of PVOH and glycerin 55% 49% Inventive capsule with modified starch 76% 67%

[0150] By using various protective colloids, it was demonstrated that the inventive process produces a multilayer capsule shell or capsule wall. While the ammonium derivative of polyvinyl alcohol (PVOH) was used as the protective colloid in the process without the addition of any additional hydroxyl groups, the capsule stability was significantly lower than when glycerin was also added, which resulted in an increase in the stability of the microcapsules. By deliberately omitting hydroxyl groups (see "Inventive capsule with ammonium derivative of PVOH") and deliberately adding hydroxyl groups (see "Inventive capsule with ammonium derivative of PVOH and glycerin"), the formation of a polyurethane layer can be demonstrated, which significantly increases stability. Example 6: Sensory evaluation of the microcapsules according to the invention

[0151] The sensory evaluation of the microcapsules was carried out as follows: The microcapsules as they are in Figure 6 The samples listed were mixed into a fabric softener and then washed. The samples were sniffed on mixed-fiber cloths made of cotton and polyester.

[0152] State-of-the-art capsule: 10 days, 50 °C, 28% perfume oil. Inventive capsule with reduced shell: 10 days, 50 °C, 59% perfume oil.

[0153] 24 test subjects assessed the fragrance intensity of the mixed-fiber wipes after washing on a scale of 1 (no odor) to 9 (very strong odor).

[0154] The microcapsules according to the invention have virtually the same odor as the microcapsules from the prior art. The advantage here lies in the stability of the microcapsules according to the invention. These exhibit greater stability despite a polymer reduction from 1:20 to 1:40, based on the perfume oil.

[0155] Due to the advantageous properties described above, consistent quality and consequently sensory stability can be expected over time with the microcapsules according to the invention compared to the prior art microcapsules. Immediately after production, the prior art microcapsules are just as good as the microcapsules according to the invention. However, over time, they lose oil more quickly and thus have a less intense odor than the microcapsules according to the invention.

Claims

1. Process for preparing isocyanate-based or isothiocyanate-based microcapsules, which comprises the following steps: (a) providing an internal non-aqueous phase, comprising at least one isocyanate having two or more isocyanate groups or at least one isothiocyanate having two or more isothiocyanate groups, and comprising a hydrophobic active ingredient to be encapsulated having an aldehyde, carboxylic acid or ester functionality; (b) providing an external aqueous phase, comprising at least one protective colloid and a catalyst, 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, in particular 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, starch or chemically, mechanically and / or enzymatically modified starch, carboxymethylcellulose and polyvinylpyrrolidone, and mixtures of the aforementioned compounds; (c) mixing the internal non-aqueous phase and the external aqueous phase, optionally in the presence of a stabilizer and / or an emulsifier, to obtain an oil-in-water emulsion; (d) first crosslinking by adding an amine that reacts at an acidic pH; (e) further crosslinking by adding an amine that reacts at an alkaline pH, so as to obtain microcapsules; (f) curing the microcapsules obtained in step (e); and optionally: (g) separating the microcapsules from the reaction solution and, if necessary, drying the microcapsules.

2. Process according to claim 1, wherein the isocyanate having two or more isocyanate groups or the isothiocyanate having two or more isothiocyanate groups is selected from the group consisting of aliphatic, cycloaliphatic, hydroaromatic, aromatic or heterocyclic polyisocyanates or polyisothiocyanates, substitution products thereof, and mixtures of the aforementioned compounds.

3. Process according to any of the preceding claims 1 or 2, wherein the at least one hydrophobic active ingredient to be encapsulated is selected from the group consisting of fragrances, flavorings, biocides, insecticides, a substance from the group of repellents, food additives, cosmetic active ingredients, pharmaceutical active ingredients, agrochemicals, dyes, fluorescent dyes, optical brighteners, solvents, waxes, silicone oils, lubricants, and mixtures of the aforementioned active ingredients.

4. Process according to any of the preceding claims 1 to 3, wherein the at least one hydrophobic 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 polyols, polyphenols and starch.

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 catalyst is diazobicyclo[2.2.2]octane (DABCO).

8. Process according to any of the preceding claims 1 to 7, wherein the first crosslinking by the amine that reacts at an acidic pH takes place at a pH of 2 to 7 and optionally at a temperature of 20°C to 30°C.

9. Process according to any of the preceding claims 1 to 8, wherein the acid-reacting amine is selected from the group consisting of acidic amino acid hydrochlorides, in particular lysine hydrochloride and ornithine hydrochloride.

10. Process according to any of the preceding claims 1 to 9, wherein the further crosslinking by the alkaline-reacting amine takes place at a pH of 7 to 14 and optionally at a temperature of 35°C to 50°C.

11. Process according to any of the preceding claims 1 to 10, wherein the alkaline-reacting amine is selected from the group consisting of di-, tri- and polyamines and guanidinium carbonate.

12. Process according to any of the preceding claims 1 to 11, wherein the curing of the microcapsules in step (f) is carried out at a temperature of up to 55 to 70°C.

13. Isocyanate-based microcapsules, comprising or consisting of: - a core, comprising at least one hydrophobic active ingredient having an aldehyde, carboxylic acid or ester functionality; and - a capsule shell, comprising an isocyanate having two or more isocyanate groups, which, in the presence of a protective colloid and a catalyst, is crosslinked in a first step by an amine that reacts at an acidic pH and in a further step by an amine that reacts at an alkaline pH, 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, in particular 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, starch or chemically, mechanically and / or enzymatically modified starch, carboxymethylcellulose and polyvinylpyrrolidone, and mixtures of the aforementioned compounds, wherein the capsule shell comprises or consists of: a first layer of polyurethane and a second layer of polyurea, wherein a linear polyurea matrix is formed during the crosslinking at an acidic pH and a spatially crosslinked polyurea matrix is formed during the crosslinking at an alkaline pH.

14. Use of the microcapsules according to claim 13 or of a suspension of microcapsules according to claim 13 to produce detergents, fabric softeners, cleaning agents, scent enhancers in liquid or solid form, cosmetics, personal care products, agricultural products or pharmaceutical products.