Process for the preparation of microcapsules

Abstract

To provide a biodegradable microcapsule satisfying some of improvement of biodegradability, no toxic effect on human and environment, maintenance of sufficient stability, excellent release behavior of an encapsulated active ingredient and the like.SOLUTION: Biodegradable microcapsules comprising or consisting of: (a) a core comprising or consisting of at least one hydrophobic active agent; (b) a cross-linked matrix or unit of at least one polysaccharide and / or at least one protein and at least one first cross-linking agent; and optionally a capsule shell comprising or consisting of a cross-linked matrix or unit of at least one first protective colloid and / or optionally at least one further cross-linking agent, microcapsules are provided that can be used in the preparation of detergents, cosmetics, personal care products, and perfume compositions.SELECTED DRAWING: Figure 10a

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to a process for preparing biodegradable microcapsules, particularly biodegradable protein- and / or polysaccharide-based microcapsules, that have balanced biodegradability, stability, and performance compared to state-of-the-art microcapsules, as well as dispersions of such microcapsules (microcapsule slurries), preferably perfume- or fragrance-containing polysaccharide- and protein-based microcapsules, encapsulating at least one hydrophobic active ingredient. Additionally, the present invention relates to biodegradable microcapsules containing at least one hydrophobic active agent obtainable by the process according to the present invention. In another aspect, the present invention relates to the use of the microcapsules and dispersions as ingredients in household products, textile care products, laundry detergents, fabric softeners, cleaning agents, liquid or solid fragrance boosters or fragrance enhancers, cosmetics, personal care products, fragrance compositions, agricultural products, pharmaceuticals, or print coatings for paper. Finally, the present invention relates to consumer products comprising such microcapsules or microcapsule dispersions. [Background technology]

[0002] Microcapsules are particles containing a core and a wall material surrounding the core, where the core can be a solid, liquid, or gaseous substance surrounded by a dense, permeable or semi-permeable wall material of a polymer. During production, the starting polymer is deposited on the substance to be encapsulated after emulsification and coacervation or interfacial polymerization. The core is also called the internal phase. Other names used for the wall include external phase, shell, or coating. Microcapsule diameters usually vary from 1 to 1000 μm. Wall thicknesses are typically 0.5 to 150 μm, but can be as thin as 5-10 μm. -9 m~5·10 -6 The amount can vary within the range of m. Typically, the amount used is 25 to 95 wt. %, but the amount used can also be 1 to 99 wt. %.

[0003] Encapsulation of active ingredients with a suitable wall material (coating material) can be done for several reasons: - Conversion of liquids into easy-to-handle powder forms (e.g. vegetable oil coatings); - time-controlled release of substances (dosage control, depot effect of medicines, pesticides and fertilizers); - Masking of taste, odor and color (e.g. bitter or pungent odorants); - Protection against light, oxidation, heat, acids or bases (e.g. vitamins, fragrance substances) - moisture protection (e.g. hygroscopic salts or minerals); - delayed loss of volatile components (e.g., aroma substances); - Prevention of premature chemical reactions with other mixed ingredients; - Improved handling before or during processing (flowability, dust formation); - Protection of personnel from harmful or unpleasant substances (chemicals, fragrance concentrates); or improvement of solubility / suspendability by surface modification.

[0004] Hydrophobic active ingredients, such as fragrances or scents, can be easily incorporated into formulations for many different uses by encapsulation.

[0005] The contents of the microcapsules may be released in a variety of ways, in particular based on one of the mechanisms described below. - The capsules are mechanically destroyed by crushing or shearing. This mechanism is used, for example, in reactive carbonless paper. The capsules are broken by melting the wall material. Based on this mechanism, ingredients such as leavening agents or flavorings are released into the baking mixture only during the baking process. - The capsule is destroyed by dissolving the wall material. This mechanism is used, for example, in powder detergents, where the encapsulated ingredients, such as enzymes, are only released during the washing process. The capsule remains intact, and the contents are gradually released by diffusion through the capsule wall. This mechanism allows, for example, for the slow and uniform release of drug components in the body.

[0006] Due to their properties, microcapsules are used, inter alia, in the printing industry, the food industry (vitamins, flavorings, plant extracts, enzymes, microorganisms), the agricultural chemical industry (fertilizers, pesticides), the feed industry (minerals, vitamins, enzymes, drugs, microorganisms), the pharmaceutical industry, the detergent industry, and the cosmetics industry.

[0007] Many everyday products, such as detergents, fabric softeners, washing powders, liquid detergents, shower gels, shampoos, deodorants, and body lotions, are nowadays perfumed with a fragrance or a mixture of fragrances. Very often, the fragrance interacts with other ingredients in the formulation or the more volatile components of the perfumed product evaporate prematurely. This usually results in the fragrance impression of the perfume changing over time or even disappearing completely.

[0008] Microencapsulation of such fragrance mixtures offers the possibility of reducing or completely preventing the interaction or evaporation of highly volatile fragrance ingredients in perfumed products.

[0009] Various capsule wall or coating materials are known for the production of microcapsules. Capsule walls can be made of natural, semi-synthetic, or synthetic materials. Natural shell materials include gum arabic, agar, agarose, maltodextrin, alginic acid or its salts, such as sodium or calcium alginate, fats and fatty acids, cetyl alcohol, collagen, chitosan, lecithin, gelatin, albumin, shellac, polysaccharides, such as starch or dextran, polypeptides, protein hydrolysates, sucrose, and waxes. Semi-synthetic capsule wall materials include chemically modified cellulose, particularly cellulose esters and cellulose ethers, such as cellulose acetate, ethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, and carboxymethyl cellulose, as well as starch derivatives, particularly starch ethers and starch esters. Synthetic shell materials are polymers, such as polyacrylates, polyamides, polyvinyl alcohol, or polyvinylpyrrolidone.

[0010] Depending on the type of capsule wall material and the manufacturing process, microcapsules are formed in each case with different properties in terms of diameter, size distribution, and physical and / or chemical properties.

[0011] Polyurea or polyurea / polyurethane microcapsules formed by polymerization between polyisocyanates and polyamines and / or diols or polyols are well known capsules used in a variety of technical fields, including perfumery.

[0012] Polyurea microcapsules obtained by reacting two polyisocyanates with a polyamine are described, for example, in WO 2011 / 161229 or WO 2011 / 160733. According to WO 2011 / 161229 or WO 2011 / 160733, the polyurea microcapsules are prepared in the presence of polyvinylpyrrolidone (PVP) as a protective colloid. WO 2012 / 107323 discloses polyurea microcapsules having a polyurea shell comprising the reaction product of a polyisocyanate with guanazole (3,5-diamino-1,2,4-triazole) and an amino acid in the presence of an anionic stabilizer or a surfactant such as anionic polyvinyl alcohol. EP 0 537 467 B describes microcapsules prepared from a polyisocyanate containing polyethylene oxide groups in the presence of a stabilizer such as polyvinyl alcohol. According to WO2007 / 096592, microencapsulation can be carried out in an oil phase emulsified in a continuous aqueous phase which is generally stabilized by a surfactant system such as polyvinyl alcohol or its carboxylated and sulfonated derivatives.

[0013] The above-mentioned exemplary delivery systems of the current prior art exhibit both good stability, i.e., the ability of the capsules to retain the active ingredient, and therefore avoid loss of volatile ingredients, and good performance, e.g., fragrance release in the case of fragrance or odorant capsules.

[0014] However, the above-mentioned microcapsules according to the latest prior art have the drawback that the polymer capsule wall or capsule shell material requires a large polymer content to ensure sufficient stability and avoid excessive loss of the active ingredient. In addition, the microencapsulation process introduces plastics into the environment, causing problems as "microplastics," which may cause environmental damage or adverse health effects if necessary.

[0015] Plastic particles are increasingly being criticized for their environmental impact, and the growing social pressure regarding environmental considerations has led to a growing demand for bio-based and biodegradable solutions. Therefore, there is a need to develop new materials for microencapsulation that will reduce microplastics in the environment. Here, bio-based and biodegradable materials are attracting attention.

[0016] Therefore, in this regard, there is a need to increasingly use biodegradable capsule wall materials in the preparation of bio-based biodegradable materials, while at the same time providing microcapsules that exhibit excellent stability and release characteristics for the application in question. It is important that not only the polymeric material of the capsule wall itself, but also the individual fragments formed during degradation, are biocompatible.

[0017] However, this challenge of using biodegradable materials to reduce the amount of microplastics in the environment is not trivial in the case of microencapsulation: desired features of microcapsules, such as olfactory properties and positive secondary properties such as high stability and toxicological stability, conflict with the requirement of rapid biodegradability in many applications.

[0018] It is particularly difficult to produce microcapsules that have both good stability and good release of active ingredients.The ability of capsules to retain active ingredients, and therefore to avoid the loss of volatile components, depends on the stability of capsules, especially in the product base.However, capsules with particularly good stability do not necessarily exhibit good biodegradability.

[0019] As the degree of cross-linking increases, the stability of the microcapsules increases, but at the same time, the ability of the capsule shell to biodegrade decreases. Very stable microcapsules can break under pressure or friction, reducing the number of microcapsules that open and release the active ingredient, resulting in a decrease in sensory and other performance. If they are too unstable, they will break down during storage and will not function.

[0020] The present invention is therefore based on the complex problem of providing microcapsules which preferably meet one, several or preferably all of the following requirements: - improved biodegradability, - absence of toxic effects on humans and the environment; - Maintain sufficient stability, - compatibility with a wide range of variability in the active ingredients to be encapsulated; - excellent release behavior of the encapsulated active ingredients, and - be accessible by known microcapsule manufacturing processes; and - The ingredients are readily available, i.e., can be derived from bio-based or sustainably produced raw materials.

[0021] Surprisingly, it has been found that this problem can be solved by preparing microcapsules from polysaccharides and / or proteins in aqueous emulsion and a crosslinking agent in the presence of a catalyst via interfacial polymerization. Crosslinking allows the formation of biodegradable, stable capsule shells or walls that can be used to encapsulate a wide range of hydrophobic or lipophilic active ingredients, respectively. Summary of the Invention [Means for solving the problem]

[0022] This problem is solved by the object of the independent patent claims. Preferred embodiments are evident from the wording of the dependent claims and the following description.

[0023] Therefore, a first object of the present invention is a process for the preparation of biodegradable protein and / or polysaccharide based microcapsules, comprising the following steps: (i) providing an internal non-aqueous phase comprising at least one first cross-linking agent and at least one hydrophobic active ingredient, and optionally at least one further cross-linking agent, and optionally at least one catalyst; (ii) providing an external aqueous phase comprising at least one protein and / or at least one polysaccharide, and optionally at least one protective colloid, and optionally adjusting the pH value of the aqueous phase to a pH value below the isoelectric point of the protein; (iii) optionally emulsifying or dispersing the internal non-aqueous phase in the external aqueous phase in the presence of at least one stabilizer and / or at least one emulsifier to obtain an oil-in-water emulsion / dispersion; (iv) optionally adding at least one further polysaccharide and / or at least one further protein; (v) performing a first cross-linking by adding at least one catalyst to obtain a microcapsule slurry; (vi) curing the microcapsule slurry at a temperature of at least 60°C and, if desired, adding at least one further polysaccharide and / or at least one further protein; (vii) cooling and, if necessary, performing a second cross-linking by adding at least one second cross-linking agent; and (viii) optionally separating the microcapsules from the microcapsule slurry and optionally drying the microcapsules or adjusting the viscosity of the microcapsule slurry by adding at least one thickening agent. in this order.

[0024] In a second aspect, the present invention relates to microcapsules comprising at least one lipophilic active ingredient, or a microcapsule slurry prepared according to the process of the present invention.

[0025] (a) a core comprising or consisting of at least one hydrophobic active agent; It is also an object of the present invention to provide biodegradable microcapsules comprising or consisting of (b) a capsule shell comprising or consisting of a crosslinked matrix or units of at least one polysaccharide and / or at least one protein and at least one first crosslinking agent; and optionally at least one first protective colloid and / or optionally at least one further crosslinking agent.

[0026] Finally, another aspect relates to the use of microcapsules according to the invention or dispersions comprising microcapsules according to the invention for the preparation of household products, textile care products, laundry detergents, fabric softeners, cleaning agents, fragrance boosters, liquid or solid scented lotions or fragrance enhancers, cosmetics, personal care products, perfume compositions, agricultural products, pharmaceuticals, or print coatings for paper.

[0027] Surprisingly, in the context of the present invention, it has been found that in the preparation of microcapsules, the combination of polysaccharides and / or proteins and subsequent cross-linking with polyisocyanates having at least two isocyanate groups leads to stable microcapsules, thus ensuring efficient encapsulation of lipophilic active ingredients and their subsequent targeted release, while the microcapsules exhibit good biodegradability due to the bio-based and biodegradable building blocks.

[0028] By using polysaccharides and / or proteins, the polyisocyanate content of the capsule wall or capsule shell material can be reduced, i.e., replaced with bio-based capsule wall components, and therefore the proportion of bio-based capsule wall components can be increased without sacrificing the stability of the microcapsule wall.

[0029] These and other aspects, features, and advantages of the present invention will become apparent to those skilled in the art upon review of the following detailed description and claims. In this regard, any feature or variation from one aspect of the present invention can be used or substituted for another aspect of the invention. Furthermore, it is understood that the examples disclosed herein explain and illustrate the present invention but are not intended to limit the invention, and in particular the invention is not limited to these examples.

[0030] Unless otherwise indicated, all percentages are by weight. Numerical examples given in the form "from x to y" are inclusive. When multiple preferred numerical ranges are given in this format, it is understood that all ranges resulting from combining the various endpoints are also included.

[0031] As used herein, the term "at least one" or "one or more" refers to one or more, for example, 2, 3, 4, 5, 6, 7, 8, 9 or more.

[0032] The term "and / or" denotes that a conjunctive or alternative is provided.

[0033] Numerical examples given in the form "x~y" are inclusive of the given value. When multiple preferred numerical ranges are specified in this format, all ranges created by combining the various endpoints are also included. [Brief explanation of the drawings]

[0034] figure [Figures 1a-1d] 1 shows diagrams of particle size distribution (d(0,5) values) of microcapsules according to the invention with different compositions. [Figure 1e] 1 is a diagram showing a comparison of the particle size distribution of microcapsules according to the state of the art and the present invention. The particle size distribution was measured using a MALVERN Mastersizer 3000. The corresponding calculation is based on the Mie theory.

[0035] [Figure 2] 1 is a diagram showing the free oil content of microcapsules according to the invention compared to microcapsules according to the state of the art.

[0036] [Figure 3] 1 is a diagram showing the free oil content of microcapsules according to the invention compared to microcapsules according to the state of the art.

[0037] [Figure 4] 1 is a diagram showing the free oil content of microcapsules according to the invention prepared without and with an additional cross-linking agent.

[0038] [Figure 5] 1 is a diagram showing the stability of microcapsules according to the invention in fabric softeners.

[0039] [Figure 6] 1 is a diagram showing the sensory evaluation of microcapsules according to the invention, where the values ​​on the y-axis use commas for decimal places.

[0040] [Figure 7] 1 is a diagram showing in general terms the correlation between stability, performance and biodegradability of microcapsules as a function of the degree of cross-linking.

[0041] [Figure 8] 1 is a diagram showing the particle size distribution (d(0,5) values) of microcapsules according to the invention based on chickpea protein.

[0042] [Figure 9] 1 is a diagram showing the free oil content of microcapsules according to the invention based on chickpea protein.

[0043] [Figure 10a-10b]FIG. 1 shows the sensory evaluation of microcapsules according to the invention based on dextrins derived from chickpea protein and pea starch compared to a pure fragrance oil standard in a fabric softener formulation, after aging for one week in fabric softener, after machine drying and after line drying, respectively.

[0044] [Figures 11a-11d] FIG. 1 shows the sensory evaluation of microcapsules according to the invention based on dextrins derived from chickpea protein and pea starch compared to a pure fragrance oil standard in a fabric softener formulation, after softener, machine drying and line drying, aged for 2 or 4 weeks, respectively.

[0045] [Figure 12a-12b] FIG. 1 shows sensory evaluation of freshly prepared and one-year-old microcapsules according to the invention based on dextrins from chickpea protein and pea starch prepared using a dual catalyst system compared to corresponding microcapsules prepared using a single DABCO catalyst or Bi catalyst, respectively. DETAILED DESCRIPTION OF THE INVENTION

[0046] In Figures 2 to 6, a dot was used as a decimal point symbol.

[0047] Detailed Description of the Invention In a first aspect, the present invention provides a process for preparing biodegradable protein and / or polysaccharide based microcapsules, comprising the following steps: (i) providing an internal non-aqueous phase comprising at least one first cross-linking agent and at least one hydrophobic active ingredient, and optionally at least one further cross-linking agent, and optionally at least one catalyst; (ii) providing an external aqueous phase comprising at least one protein and / or at least one polysaccharide, and optionally at least one protective colloid, and optionally adjusting the pH value of the aqueous phase to a pH value below the isoelectric point of the protein; (iii) optionally emulsifying or dispersing the internal non-aqueous phase in the external aqueous phase in the presence of at least one stabilizer and / or at least one emulsifier to obtain an oil-in-water emulsion / dispersion; (iv) optionally adding at least one further polysaccharide and / or at least one further protein; (v) performing a first cross-linking by adding at least one catalyst to obtain a microcapsule slurry; (vi) curing the microcapsule slurry at a temperature of at least 60°C and, if desired, adding at least one further polysaccharide and / or at least one further protein; (vii) cooling and, if necessary, performing a second cross-linking by adding at least one second cross-linking agent; and (viii) optionally separating the microcapsules from the microcapsule slurry and optionally drying the microcapsules or adjusting the viscosity of the microcapsule slurry by adding at least one thickening agent. in this order.

[0048] In another variant, the process for preparing biodegradable protein and / or polysaccharide based microcapsules comprises the following steps: (i) providing an internal non-aqueous phase comprising at least one first cross-linking agent and at least one hydrophobic active ingredient, and optionally at least one further cross-linking agent, and optionally at least one catalyst; (ii) providing an external aqueous phase comprising at least one protective colloid and, optionally, at least one protein and / or at least one polysaccharide, and, optionally, adjusting the pH value of the aqueous phase to a pH value below the isoelectric point of the protein; (iii) optionally emulsifying or dispersing the internal non-aqueous phase in the external aqueous phase in the presence of at least one stabilizer and / or at least one emulsifier to obtain an oil-in-water emulsion / dispersion; (iv) optionally adding at least one polysaccharide or at least one further polysaccharide and / or at least one protein or at least one further protein; (v) performing a first cross-linking by adding at least one catalyst to obtain a microcapsule slurry; (vi) curing the microcapsule slurry at a temperature of at least 60°C and, if desired, adding at least one further polysaccharide and / or at least one further protein; (vii) cooling and, if necessary, performing a second cross-linking by adding at least one second cross-linking agent; and (viii) optionally separating the microcapsules from the microcapsule slurry and optionally drying the microcapsules or adjusting the viscosity of the microcapsule slurry by adding at least one thickening agent. in this order.

[0049] In the context of the present invention, microcapsules are understood to be microparticles containing at least one or more active ingredients as the core material inside the capsule and surrounded by a capsule shell or capsule wall. The active ingredients are preferably hydrophobic or lipophilic active ingredients. Such active ingredients are insoluble or poorly soluble in water but readily soluble in oils and fats. The terms "microcapsule" and "capsule" or "hydrophobic" and "lipophilic" are used interchangeably within the context of the present invention.

[0050] In the context of the present invention, the capsule shell or capsule wall is preferably composed of several cross-linked matrices or cross-linked units, preferably of different compositions, produced by several process steps or process sequences, particularly the cross-linking step, during the preparation of the microcapsules according to the present invention. The cross-linked matrix comprises or consists of at least one polysaccharide and / or at least one protein. These capsule wall components are cross-linked to each other by a cross-linking agent and a catalyst via interfacial polymerization via a selectively catalyzed mechanism to form a three-dimensional network of polysaccharide, protein, and cross-linking agent.

[0051] In the first step (i) of the process according to the invention, an internal non-aqueous phase is provided which comprises at least one cross-linking agent, at least one hydrophobic active agent to be encapsulated, and optionally further cross-linking agents.

[0052] Furthermore, if necessary, a catalyst is already added in this step (i), especially in the case of a dual catalyst system. Preferably, the catalyst is oil-soluble. Therefore, the internal non-aqueous phase can further comprise a catalyst.

[0053] The first crosslinking agent according to the first and / or second aspect of the present invention for preparing the capsule shell or capsule wall is a crosslinking agent selected from the group consisting of polyisocyanates having two or more isocyanate groups, selected from the group consisting of aliphatic, cycloaliphatic, hydroaromatic, aromatic or heterocyclic polyisocyanates, their substitution products, and mixtures of two or more of the aforementioned first crosslinking agents.

[0054] The at least one isocyanate or polyisocyanate having two or more isocyanate groups used in the process according to the invention for preparing biodegradable protein and / or polysaccharide-based microcapsules contains at least two isocyanate groups for polymerization to form a polymer network that forms the capsule shell or capsule wall.

[0055] Polyisocyanates are R-substituted organic derivatives (RN=C=O) of isocyanic acid (HN=C=O). Organic isocyanates are compounds in which an isocyanate group (-N=C=O) is attached to an organic radical. Multifunctional isocyanates or polyisocyanates are those compounds that contain at least two or more isocyanate groups (-N=C=O) in the molecule, i.e., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200, or even more. Polyisocyanates with two isocyanate groups are also called diisocyanates.

[0056] Polyisocyanates can be classified as aliphatic, cycloaliphatic, hydroaromatic, aromatic or heterocyclic isocyanates or polyisocyanates. Furthermore, the polyisocyanates according to the invention can be linear or branched.

[0057] Polyisocyanates, especially aromatic polyisocyanates, are highly reactive compounds. The polyaddition reaction of polyisocyanates with diols or polyols forms the basis of polyurethane chemistry, while the polyaddition reaction of polyisocyanates with amines forms the basis of polyurea chemistry.

[0058] According to the invention, at least difunctional, preferably polyfunctional, polyisocyanates are used, i.e. all aliphatic, cycloaliphatic and aromatic isocyanates are suitable, provided they have at least two reactive isocyanate groups.

[0059] Aliphatic, cycloaliphatic, hydroaromatic, aromatic or heterocyclic polyisocyanates, their substitution products and mixtures of the aforementioned monomeric or oligomeric compounds are particularly preferred. Of the polyisocyanates specified above, aliphatic and / or aromatic compounds are preferably used.

[0060] In a preferred embodiment of the process according to the invention, the polyisocyanates contain an average of 2 to 5 functional -N=C=O groups, including, for example, aliphatic, cycloaliphatic and aromatic di-, tri- and higher polyisocyanates.

[0061] Of the polyisocyanates mentioned above, diisocyanates and polyisocyanates having three functional groups -N=C=O are particularly preferred and are therefore primarily used in the practice of the present invention. Preferably, diisocyanates having the general structure O=C=NRN=C=O (where R represents an aliphatic, alicyclic, or aromatic group) are used. Preferably, the radical has 5 or more carbon atoms.

[0062] In a preferred embodiment of the process according to the invention, the at least one polyisocyanate having two or more isocyanate groups is selected from the group consisting of aliphatic and / or aromatic polyisocyanates. In an even more preferred variant of the process according to the invention, the at least one polyisocyanate is a combination of two different aliphatic polyisocyanates or a combination of an aliphatic and an aromatic polyisocyanate.

[0063] The number of functional groups allows for optimal cross-linking or networking of the capsule wall to be achieved, providing microcapsules that exhibit long-term sustained release of the active ingredient as well as good stability in consumer products.

[0064] In a preferred variant of the process according to the invention, the polyisocyanate is an aliphatic polyisocyanate.

[0065] The term "aliphatic polyisocyanate" refers to any polyisocyanate molecule that is not aromatic and further contains at least two isocyanate groups, i.e., at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200 or more isocyanate groups directly bonded to a corresponding number of different C atoms of the same aliphatic molecule, and derivatives of such compounds.

[0066] Aliphatic polyisocyanate molecules containing at least two isocyanate groups, i.e., at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200 or more isocyanate groups, may further be linear, branched or cyclic and may have optional substituents including, for example, aliphatic substituents, aromatic substituents, one or more heteroatoms such as nitrogen, oxygen, phosphorus and / or sulfur, halogens such as fluorine, chlorine, bromine and / or iodine, and / or other functional groups such as alkoxy groups.

[0067] The linear aliphatic polyisocyanate molecule is preferably selected from C2- to C20-linear alkyl, preferably C3- to C15-linear alkyl, C4- to C12-linear alkyl, C5- to C10-linear alkyl, C6- to C9-linear alkyl, or C7- to C8-linear alkyl. Preferably, the linear aliphatic molecule does not contain an aromatic structure.

[0068] The branched chain aliphatic polyisocyanate molecule is preferably selected from C2- to C20-branched chain alkyl, preferably C3- to C15-branched chain alkyl, C4- to C12-branched chain alkyl, C5- to C10-branched chain alkyl, C6- to C9-branched chain alkyl, and C7- to C8-branched chain alkyl.

[0069] The shorter the carbon chain of the polyisocyanate molecule, the faster the reaction rate compared to its longer chain analogues.

[0070] The cycloaliphatic polyisocyanate molecule contains at least one non-aromatic ring structure, i.e., 1, 2, 3, 4, or more, and the ring structure itself preferably consists of only C atoms. Of course, the C atoms of the ring structure may have suitable substituents. At least one ring structure preferably independently consists of a 3-, 4-, 5-, 6-, 7-, or 8-membered ring. Preferably, the cycloaliphatic molecule contains 2 to 20 C atoms, for example, 3 to 15 C atoms, 4 to 12 C atoms, 5 to 10 C atoms, 6 to 9 C atoms, or 7 to 8 C atoms.

[0071] In another variant of the process according to the invention, the polyisocyanate is an aromatic polyisocyanate. The term "aromatic polyisocyanate" refers to any polyisocyanate compound in which two or more isocyanate groups are bonded directly to an aromatic C atom and which contains, for example, a phenyl, tolyl, xylyl, naphthyl or diphenyl moiety as the aromatic component, as well as derivatives of such polyisocyanate compounds.

[0072] Aromatic polyisocyanates are preferably used in the process according to the invention because they react significantly faster than aliphatic polyisocyanates.

[0073] Linear, branched, or cyclic aliphatic or aromatic polyisocyanates can exist as monomers or polymers. Monomeric polyisocyanates are molecules that are not bound to other molecules, particularly not through one or more crosslinkers. Polymeric polyisocyanates contain at least two monomers linked by one or more crosslinkers. The at least two monomers do not necessarily have to be the same monomer; they can be different. Polymeric polyisocyanates preferably contain at least two or more monomers, i.e., at least 2, 3, 4, 5, 10, 20, 30, 40, 50, 100, or more monomers linked to each other through at least one crosslinker.

[0074] The linear, branched, or cyclic aliphatic or aromatic polyisocyanates preferably have a defined size / defined molecular weight that allows for reactivity with one or more crosslinking agents. Examples of suitable molecular weights are preferably from about 100 g / mol to 5:10 4 g / mol, preferably 120 g / mol to 2 10 4 g / mol, 140g / mol~10 4 g / mol, 160 g / mol ~ 5·10 3 g / mol, 180 g / mol ~ 2·10 3 g / mol, 200g / mol~10 3 g / mol, 220 g / mol to 900 g / mol, 240 g / mol to 800 g / mol, 260 g / mol to 700 g / mol, 280 g / mol to 600 g / mol, 300 g / mol to 500 g / mol, 320 g / mol to 450 g / mol, or 340 g / mol to 400 g / mol.

[0075] Any number of different linear, branched, and / or cycloaliphatic and / or aromatic polyisocyanates can be used. For example, at least one, i.e., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 different linear aliphatic polyisocyanates can be used. For example, at least one, i.e., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 different branched aliphatic polyisocyanates can be used. For example, at least one, i.e., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 different (branched) cycloaliphatic polyisocyanates can be used.

[0076] Preferably, derivatives of linear, branched, and / or cyclic aliphatic polyisocyanates are used. As used herein, derivatives are understood in the broadest sense as compounds derived from compounds by chemical reaction. Examples of derivatives include oligomers and / or adducts of the above-mentioned linear or branched aliphatic polyisocyanates. Preferred oligomers are biurets, isocyanurates, uretdione, and iminooxadiazinedione, and preferred adducts are trimethylolpropane adducts. These oligomers / adducts are well known in the art and are disclosed, for example, in U.S. Pat. No. 4,855,490(A) or U.S. Pat. No. 4,144,268(A).

[0077] Preferably, the aliphatic polyisocyanates are present only in monomeric and / or dimerized (as isocyanates) or oligomeric form.

[0078] Derivatives of linear, branched or cyclic polyisocyanates and / or mixtures thereof can also be obtained by reacting polyisocyanates with polyalcohols (for example glycerol), polyamines, polythiols (for example dimercaprol).

[0079] The isocyanate compounds defined above specifically include various isomers, when present, alone or in combination, for example, methylenebis(cyclohexylisocyanate) (H12MDI) includes 4,4'-methylenebis(cyclohexylisocyanate), 2,4'-methylenebis(cyclohexylisocyanate), and / or 2,2'-methylenebis(cyclohexylisocyanate).

[0080] Exemplary aliphatic polyisocyanates include commercially available aliphatic water-dispersible polyisocyanates based on hexamethylene diisocyanate, such as BAYHYDURN 304 and BAYHYDUR N3Q5; low viscosity multifunctional hexamethylene diisocyanate-based aliphatic polyisocyanates, such as DESMODUR N3400, DESMODUR N3600, DESMODUR N3700, and DESMODUR N3900; and hexamethylene diisocyanate-based aliphatic polyisocyanates, such as DESMODUR 3600 and DESMODUR N100, each of which is available from Bayer Corporation, Pittsburgh, PA.

[0081] According to another preferred variant of the present invention, the linear or branched aliphatic polyisocyanate is or is selected from the group consisting of pentamethylene diisocyanate (PDI such as Stabios D-370N or D-376N from Mitsui Chemicals Inc., Japan), hexamethylene diisocyanate (HDI), lysine triisocyanate ethyl ester, lysine diisocyanate ethyl ester, and derivatives thereof, preferably each of said derivatives containing more than one isocyanate group and optionally further containing one or more groups selected from the group consisting of biuret, isocyanurate, uretdione, iminooxadiazinedione and trimethylolpropane adduct, and / or wherein the cycloaliphatic polyisocyanate is isophorone diisocyanate (IPDI), 1,3-bis(isocyanatomethyl)cyclohexane (Takenate from Mitsui Chemicals Inc., Japan). 600), 1,2-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, methylenebis(cyclohexylisocyanate) (H12MDI) and derivatives thereof, preferably each of said derivatives containing more than one isocyanate group and optionally further containing one or more groups selected from the group consisting of biuret, isocyanurate, uretdione, iminooxadiazineion, trimethylolpropane adducts of H6XDI (such as TMP adducts), in particular Takenate D-120N manufactured by Mitsui Chemicals Inc., Japan.

[0082] Aliphatic polyisocyanates obtained from renewable raw materials, such as PDI (Stabio D-370N or D-376N, manufactured by Mitsui Chemicals Inc., Japan), are particularly preferred. It has been found that such aliphatic polyisocyanates obtained from renewable raw materials do not affect the quality / properties of the core-shell capsules.

[0083] Other suitable commercially available polyisocyanates include LUPRANAT M20 (BASF), with an average n of 0.7; PA PI 27 (Dow Chemical), with an average n of 0.7; MONDUR MR (Bayer), with an average n of 0.8; MONDUR MR Light (Bayer), with an average n of 0.8; MONDUR 489 (Bayer), with an average n of 1.0; and other isocyanate monomers such as poly-[(phenylisocyanate)-co-formaldehyde (Aldrich Chemical, Milwaukee, WI), DESMODUR N3200 (Bayer), and TAKENATE D110-N (Mitsui Chemicals Corporation, Rye Brook, NY). Other representative polyisocyanates include those designated TAKENATE D-110N (Mitsui), DESMODUR L75 (Bayer), and DESMODUR IL (Bayer).

[0084] In a preferred variant, the polyisocyanate used for the preparation of the polyurea / polyurethane microcapsules according to the invention is used as the sole polyisocyanate component, i.e. without being mixed with other polyisocyanate components different from it.

[0085] Examples of monomeric polyisocyanates which can be used in accordance with the present invention and which contain at least two polyisocyanate groups are: Ethylene diisocyanate, trimethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethyl diisocyanate, ethylene diisothiocyanate, tetramethylene diisothiocyanate, hexamethylene diisothiocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1,3-phenylene diisocyanate and 1,4 -Phenylene diisocyanate mixture, p-phenylene diisothiocyanate, xylylene-1,4-diisothiocyanate, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, mixture of 2,4-toluylene diisocyanate and 2,6-toluylene diisocyanate, xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate, and mixture of xylylene-1,4-diisocyanate and xylylene-1,3-diisocyanate, 2,4-hexahydrotoluylene diisocyanate 2,6-hexahydrotoluylene diisocyanate, mixture of 2,4-hexahydrotoluylene diisocyanate and 2,6-hexahydrotoluylene diisocyanate, hexahydro-1,3-phenylene diisocyanate, hexahydro-1,4-phenylene diisocyanate, mixture 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-trimethylbenzene-2,4-diisocyanate Isopropylbenzene-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, toluylene-2,4,6-triisocyanate, dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate, or mixtures of the foregoing compounds is.

[0086] As polymerizable compounds containing at least two polyisocyanate groups, preference is given to large-scale produced di- and polyisocyanates, such as TDI: toluylene diisocyanate (an isomer mixture of 2,4- and 2,6-toluylene diisocyanate in a ratio of 80:20), HDI: hexamethylene diisocyanate-(1,6), IPDI: isophorone diisocyanate or DMDI: diphenylmethane-4,4'-diisocyanate.

[0087] Other particularly preferred monomeric polyisocyanate compounds are diisocyanates, such as 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- and 2,4,4-trimethyl-1,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3- and 1,4-diisocyanatocyclohexane, 1-polyisocyanato-3,3,5-trimethyl-5-polyisocyanatomethylcyclohexane (isophorone diisocyanate), 4,4'-diisocyanatodicyclohexylmethane, 2,4- and 2,6-diisocyanatomethylcyclohexane, and mixtures thereof. In principle, aromatic polyisocyanates, such as toluylene diisocyanate or 4,4'-diisocyanatodiphenylmethane, can also be used.

[0088] Other specific examples of diisocyanates include, for example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), hydrogenated MDI (H12MDI), xylylene diisocyanate (XDI), tetramethyl xylene diisocyanate (TMXD1), 4,4'-diphenyldimethylmethane diisocyanate, di- and tetraalkyldiphenylmethane diisocyanates, 4,4'-dibenzyl diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and mixtures thereof, optionally, isomers of toluylene diisocyanate (TDI), 1-methyl-2,4-diisocyanatocyclohexane, 1,6-diisocyanato-2,2,4-trimethylhexane, 1,6-diisocyanato-2,4,4-trimethylhexane, and the like. Examples of suitable diisocyanates include perfluorohexane, 1-isocyanatomethyl-3-isocyanato-1,5,5-trimethylcyclohexane, chlorinated and brominated diisocyanates, phosphorus-containing diisocyanates, 4,4'-diisocyanatophenylperfluoroethane, tetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate, (HDI), dicyclohexylmethane diisocyanate, cyclohexane-1,4-diisocyanate, ethylene diisocyanate, phthalic acid bisisocyanatoethyl ester, and polyisocyanates having reactive halogen atoms such as 1-chloromethylphenyl-2,4-diisocyanate, 1-bromomethyl-phenyl-2,6-diisocyanate, and 3,3-bischloromethylether-4,4'-diphenyl diisocyanate.

[0089] Surprisingly, it has been found that the use of long chain aliphatic diisocyanates, particularly those having 6, 7, 8, 9, 10 or even more carbon atoms, results in the formation of more stable capsule shells or walls.

[0090] In a particularly preferred embodiment, the internal non-aqueous phase comprises a mixture of two or more different polymerizable polyisocyanates capable of forming a mixed polymer, for example, polyisocyanates having different chain lengths.

[0091] Proportionally, derivatives of polyisocyanates which can be prepared by modifying the above-mentioned diisocyanates or mixtures thereof in known manner and which contain, for example, uretdione, urethane, isocyanurate, biuret and / or allophanate groups can also be used in the process according to the invention.

[0092] Combinations of at least two different, preferably aliphatic, polyisocyanates or combinations of at least one aliphatic polyisocyanate with at least one aromatic polyisocyanate are very particularly preferred.

[0093] Such combinations take advantage of the different reaction rates of polyisocyanates: aromatic polyisocyanates react significantly faster than aliphatic polyisocyanates, and the reaction rate is faster for short-chain aliphatic polyisocyanates, i.e., aliphatic polyisocyanates having 1 to 5 carbon atoms, preferably 3 to 5 carbon atoms, compared to their long-chain analogs.

[0094] Therefore, in a further preferred embodiment of the present invention, the different aliphatic and / or aromatic polyisocyanates also have different chain lengths. In this context, long-chain polyisocyanates preferably have 6, 7, 8, 9, 10, 11, 12, 13, 14, 20, 25 or more carbon atoms, but even more preferably they have 6 to 12 carbon atoms, particularly preferably 6 to 8 carbon atoms. Shorter-chain polyisocyanates are understood to be polyisocyanates having 1 to 5 carbon atoms, preferably 3 to 5 carbon atoms.

[0095] According to the invention, preference is given to a combination of a short-chain aliphatic polyisocyanate (C1, C2, C3, C4, C5) with a long-chain aliphatic polyisocyanate (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more), or a combination of a short-chain aliphatic polyisocyanate (C1, C2, C3, C4, C5) with a long-chain aromatic polyisocyanate. and combinations of long chain aliphatic polyisocyanates (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or higher) with short chain aromatic polyisocyanates.

[0096] Particularly preferred in this context is the use of mixtures of different aliphatic polyisocyanates having two or more isocyanate groups with a chain length of 1 to 12 carbon atoms, preferably 3 to 8 carbon atoms, particularly preferably 4 to 7 carbon atoms, in the chain for the preparation of biodegradable microcapsules according to the invention.

[0097] Aliphatic polyisocyanates are particularly preferred in this context due to their chemical relationship to bio-based systems: for example, lysine and 1,5-diisocyanatopentane both have the same degradation product, 1,5-diaminopentane, and are therefore particularly suitable for use in the preparation of bio-based, biodegradable microcapsules, given environmental considerations.

[0098] The main embodiment includes a mixture of long-chain diisocyanates to short-chain diisocyanates in any mixing ratio, more preferably in the range of 4:1 to 1:4, and particularly preferably in the range of 2:1 to 1:2.

[0099] Examples of preferred specific mixtures of at least one aliphatic polyisocyanate and at least one aromatic polyisocyanate are mixtures of the biuret of hexamethylene diisocyanate and the trimethylol adduct of xylylene diisocyanate, mixtures of the biuret of hexamethylene diisocyanate and the polyisocyanurate of a diisocyanate, or mixtures of the biuret of hexamethylene diisocyanate and the trimethylolpropane adduct of toluene diisocyanate.

[0100] According to the present invention, in the combination of the above-mentioned short-chain aliphatic polyisocyanates with long-chain aliphatic polyisocyanates, or in the combination of the short-chain aliphatic polyisocyanates with long-chain aromatic polyisocyanates, or in the combination of the long-chain aliphatic polyisocyanates with short-chain aromatic polyisocyanates, the polyisocyanates are present in a mixture of monomeric, oligomeric or polymeric forms, respectively.

[0101] Preferably, this results in: The following combinations are obtained for use in the process according to the invention: - short-chain aliphatic polyisocyanates (monomers or oligomers or polymers) and short-chain aliphatic polyisocyanates (monomers or oligomers or polymers); - short-chain aliphatic polyisocyanates (monomers or oligomers or polymers) and long-chain aliphatic polyisocyanates (monomers or oligomers or polymers); - short-chain aliphatic polyisocyanates (monomers or oligomers or polymers) and short-chain aromatic polyisocyanates (monomers or oligomers or polymers); - short-chain aliphatic polyisocyanates (monomers or oligomers or polymers) and long-chain aromatic polyisocyanates (monomers or oligomers or polymers); - long-chain aliphatic polyisocyanates (monomers or oligomers or polymers) and short-chain aliphatic polyisocyanates (monomers or oligomers or polymers); - long-chain aliphatic polyisocyanates (monomers or oligomers or polymers) and long-chain aliphatic polyisocyanates (monomers or oligomers or polymers); - long-chain aliphatic polyisocyanates (monomers or oligomers or polymers) and short-chain aromatic polyisocyanates (monomers or oligomers or polymers); - Long-chain aliphatic polyisocyanates (monomers) and long-chain aromatic polyisocyanates (oligomers or polymers).

[0102] It has been observed that the selection of at least two aliphatic polyisocyanates of different chain lengths and degrees of polymerization, or a mixture of aliphatic and aromatic polyisocyanates, leads to significant improvements in stability and performance (fragrance release in the case of fragrance or odorant capsules) due to differences in reaction rate, dissociation, and crosslinking structure of the polyisocyanate components.

[0103] Combinations of the aforementioned polyisocyanates or polyisocyanate mixtures of two different aliphatic polyisocyanates or one aliphatic and one aromatic polyisocyanate can be used to form particularly stable and better, i.e., more densely branched, crosslinks within the capsule shell.

[0104] Thus, high-performance (fragrance-releasing) microcapsules made from either a mixture of aliphatic and aromatic polyisocyanates or a mixture of two different aliphatic polyisocyanates can be prepared based on the process described herein. Such microcapsules are very stable and feature excellent fragrance storage properties, which is therefore reflected in better performance (fragrance release) of the capsules, for example in the field of odorant or fragrance encapsulation.

[0105] As shown in the embodiments below, the use of two different polyisocyanates results in microcapsules that further exceed the stability of microcapsules made from a single polyisocyanate system.

[0106] Microcapsules made from an aliphatic-aliphatic polyisocyanate mixture are as good as microcapsules made from an aliphatic-aromatic polyisocyanate mixture, as shown in the following embodiments. Therefore, in principle, a combination of at least two different polymerizable (preferably aliphatic and / or aromatic) polyisocyanates is preferred in the present invention.

[0107] The proportion of the first crosslinker in the internal non-aqueous phase is in the range of 0.1 to 5 wt.%, preferably in the range of 0.15 to 2.5 wt.%, based on the total weight of the non-aqueous phase. Most preferably, the first crosslinker is provided in the internal non-aqueous phase in the range of 0.5 to 1 wt.%, based on the total weight of the non-aqueous phase.

[0108] The first cross-linking agent is added to the internal non-aqueous phase neat, for example as a solid, or in the form of an aqueous solution.

[0109] The first crosslinker is present in the aqueous solution at a concentration of 0.01 to 2 mol / l, preferably 0.1 to 1.5 mol / l, and most preferably 0.5 to 1.0 mol / l. The solution has a pH value of 7 to 14, preferably 12.

[0110] At least one additional cross-linking agent is optionally added to the internal non-aqueous phase to improve cross-linking of the at least one polysaccharide and / or the at least one protein, the additional cross-linking agent being different from the first cross-linking agent.

[0111] However, in the case of chickpea-based microcapsules, for example, preferably no additional cross-linking agent is used, as the resulting microcapsules already exhibit excellent properties, thus allowing for a reduction in the overall components required to prepare efficient microcapsules. Nevertheless, additional cross-linking agents can be added to further improve capsule properties.

[0112] Further cross-linking agents are selected from the group consisting of transglutaminase, peroxidase, secondary plant substances selected from the group consisting of polyphenols, in particular tannins, gallic acid, ferulic acid, hesperidin, cinnamaldehyde, vanillin, carvacrol, and mixtures of two or more of the aforementioned cross-linking agents.

[0113] Transglutaminase as an enzyme catalyzes the cross-linking of two amino acids, glutamine and lysine, via isopeptide bonds. The phenolic groups of secondary plant compounds cross-link peptides via hydrogen bonds. The aldehydes, cinnamaldehyde and vanillin, covalently react with free amino groups of proteins via their reactive aldehyde groups.

[0114] Among the aforementioned additional cross-linking agents, cinnamaldehyde, tannin and gallic acid are particularly preferred.

[0115] Particularly advantageous combinations of the first crosslinker with the further crosslinker are Polyisocyanates and transglutaminase; Polyisocyanates and peroxidases; Polyisocyanates and polyphenols; Polyisocyanates and tannins; Polyisocyanate and gallic acid; Polyisocyanate and ferulic acid; Polyisocyanate and hesperidin; Polyisocyanate and cinnamaldehyde; Polyisocyanate and vanillin; Polyisocyanate and carvacrol; or Mixtures of two or more of the polyisocyanates with the additional crosslinkers listed above is.

[0116] The content of the additional crosslinker in the internal non-aqueous phase is in the range of 0.05 to 5 wt.%, preferably in the range of 0.1 to 2 wt.%, based on the total weight of the non-aqueous phase. Most preferably, the additional crosslinker is used in the internal non-aqueous phase in the range of 0.15 to 1 wt.%, based on the total weight of the non-aqueous phase.

[0117] The additional cross-linking agent is added to the internal non-aqueous phase neat, for example as a solid, or in the form of an aqueous solution.

[0118] The additional crosslinker is present in the aqueous solution at a concentration of 0.01 to 2 mol / l, preferably at a concentration of 0.1 to 1.5 mol / l, most preferably at a concentration of 0.5 to 1.0 mol / l. The solution has a pH value of 7 to 14, preferably a pH value of 12.

[0119] By using a combination of at least one first cross-linking agent and at least one further cross-linking agent which are different from one another, the stability of the microcapsules is significantly improved and therefore the rate of leaked perfume oil is reduced.

[0120] Due to the low proportion of polyisocyanate components, the present invention allows for the preparation of protein- and / or polysaccharide-based microcapsules, in which the absolute proportion of polyisocyanate is only 1 / 50 of the total capsule weight containing at least one lipophilic active ingredient. Thus, protein- and / or polysaccharide-based microcapsules having a polyisocyanate content of only 0.6 wt.% based on the total capsule weight can be prepared by the process according to the present invention. Preferably, the polyisocyanate content is about 1.8 wt.% of the capsule weight. Despite the low polyisocyanate content, the microcapsules according to the present invention are characterized by high stability.

[0121] In step (i) of the process according to the present invention, at least one crosslinking agent, together with at least one or more active ingredients to be encapsulated, is first substantially dissolved in an inert non-aqueous solvent or a solvent mixture of inert non-aqueous solvents, if desired. By "substantially dissolved," we mean that at least 90 wt.%, preferably at least 98 wt.%, and more preferably 99.9 wt.% of the aforementioned components are dissolved in the solvent or solvent mixture for use in the process. Preferably, the at least one polyisocyanate and at least one active ingredient to be encapsulated are completely dissolved in the solvent or solvent mixture. If the solvent does not provide sufficient solubility for the isocyanate, this drawback can be overcome by using a suitable solubility promoter.

[0122] Preferred solvents for the internal non-aqueous phase are immiscible with water, do not react with the isocyanate component or the active ingredient, and have little or no odor in the amounts used.

[0123] The term "solvent" in the context of the present invention includes all types of oil bodies or oil components, in particular vegetable oils, such as canola oil, sunflower oil, soybean oil, olive oil, etc., modified vegetable oils, such as alkoxylated sunflower oil or soybean oil, synthetic (tri)glycerides, such as technical mixtures of mono-, di-, and triglycerides of C6 to C22 fatty acids, fatty acid alkyl esters, such as methyl or ethyl esters of vegetable oils (Agnique® ME18 RD-F, Agnique® ME18 SD-F, Agnique® ME12C-F, Agnique® ME1270), fatty acid alkyl esters based on these C6 to C22 fatty acids, mineral oils, and mixtures thereof.Examples of suitable and preferred lipophilic solvents are: Guerbet alcohols, which are based on fatty alcohols having 6 to 18, preferably 8 to 10, carbon atoms; esters of linear C6 to C22 fatty acids with linear or branched C6 to C22 fatty alcohols, or esters of branched C6 to C13 carboxylic acids with linear or branched C6 to C22 fatty alcohols, such as myristyl myristate, myristyl palmitate, myristyl stearate, myristyl isostearate, myristyl oleate, myristyl behenate, myristyl erucate, cetyl myristate, cetyl palmitate, cetyl stearate, cetyl isostearate, cetyl oleate, cetyl behenate, cetyl rucate, stearyl myristate, stearyl palmitate, stearyl stearate, isostearyl stearyl phosphate, stearyl oleate, stearyl stearate, stearyl erucate, isostearyl myristate, isostearyl palmitate, isostearyl stearate, isostearyl isostearate, isostearyl oleate, isostearyl behenate, oleyl myristate, oleyl palmitate, oleyl stearate, oleyl isostearate, oleyl oleate, oleyl behenate, oleyl erucate, behenyl myristate, behenyl palmitate, behenyl stearate, behenyl isostearate, behenyl oleate, behenyl behenate, behenyl erucate, erucyl myristate, erucyl palmitate, erucyl stearate, erucyl isostearate, erucyl oleate, erucyl behenate, and erucyl erucate.

[0124] Also included are esters of linear C6 to C22 fatty acids with branched fatty alcohols, in particular 2-ethylhexanol, esters of C18 to C38 alkylhydroxycarboxylic acids with linear or branched C6 to C22 fatty alcohols, in particular dioctylalate, esters of linear and / or branched fatty acids with polyhydric alcohols (for example propylene glycol, dimerdiol or trimertriol) and / or Guerbet alcohols, triglycerides based on C6 to C10 fatty acids, liquid mono- / di- / triglycerides of C6 to C18 fatty acids, esters of C6 to C22 fatty alcohols and / or Guerbet alcohols with aromatic carboxylic acids, in particular benzoic acid, esters of C2 to C12 dicarboxylic acids with linear or branched alcohols containing 1 to 22 carbon atoms or 2 to 10 carbon atoms and 2 to 6 hydroxycarboxylic acids. Also suitable are esters with polyols containing silyl groups, vegetable oils, branched primary alcohols, substituted cyclohexanes, linear or branched C6-C22 fatty alcohol carbonates such as dicaprylyl carbonate (Cetiol® CC), Guerbet carbonates based on fatty alcohols containing 6 to 18, preferably 8 to 10, carbon atoms, benzoic acid esters with linear or branched C6-C22 alcohols, linear or branched, symmetrical or asymmetrical dialkyl ethers containing 6 to 22 carbon atoms per alkyl group such as dicaprylyl ether, ring-opening products of epoxidized fatty acid esters with polyols, silicone oils (cyclomethicone, silicone methicone grades, etc.), aliphatic or naphthenic hydrocarbons such as squalane, squalene, or dialkylcyclohexanes, and / or mineral oil.

[0125] Preferred solvents also include esters of linear C6-C22 fatty acids with branched fatty alcohols, esters of C18-C38 alkylhydroxycarboxylic acids with linear or branched C6-C22 fatty alcohols, linear or branched C6-C22 fatty alcohols, in particular dioctyl malate, esters of linear and / or branched fatty acids with polyhydric alcohols, such as propylene glycol, dimerdiol or trimertriol, and / or Guerbet alcohols, triglycerides based on C6-C10 fatty acids, liquid mono- / di- / triglycerides based on C6-C18 fatty acids, esters of C6-C22 fatty alcohols and / or Guerbet alcohols with aromatic carboxylic acids, in particular benzoic acid, esters of C2-C12 dicarboxylic acids with linear or branched alcohols containing 1 to 22 carbon atoms or 2 to 10 carbon atoms and 2 to 6 hydroxyl groups. These include esters of polyols containing alkyl groups, vegetable oils, branched primary alcohols, substituted cyclohexanes, linear and branched C6-C22 fatty alcohol carbonates, such as dicaprylyl carbonate (Cetiol® CC), Guerbet carbonates based on fatty alcohols containing 6 to 18, preferably 8 to 10, carbon atoms, esters of benzoic acid with linear or branched C6-C22 alcohols, linear or branched, symmetrical or asymmetrical dialkyl ethers containing 6 to 22 carbon atoms per alkyl group, such as dicaprylyl ether (Cetiol® OE), ring-opening products of epoxidized fatty acid esters with polyols, silicone oils (cyclomethicone, silicone methicone type, etc.) and / or aliphatic or naphthenic hydrocarbons, such as squalane, squalene, or dialkylcyclohexanes.

[0126] Furthermore, liquid straight-chain and / or branched-chain and / or saturated or unsaturated hydrocarbons or any mixture thereof can be used as solvents within the scope of the present invention, which can be, for example, alkanes having 4 to 22, preferably 6 to 18, carbon atoms, or any mixture thereof.

[0127] Particularly advantageously suitable as inert solvents for the internal non-aqueous phase are alkylaromatic hydrocarbons, such as diisopropylnaphthalene or substituted biphenyls, chlorinated diphenyls, paraffins, chlorinated paraffins, natural vegetable oils, such as cottonseed oil, peanut oil, palm oil, tricresyl phosphate, silicone oils, dialkyl phthalates, dialkyl adipates, partially hydrogenated terphenyls, alkylated biphenyls, alkylated naphthalenes, diaryl ethers, aryl alkyl ethers, and higher alkylated benzenes, benzyl benzoate, isopropyl myristate, and any mixtures of these hydrophobic solvents, as well as mixtures of one or more of these hydrophobic solvents with kerosene, paraffins, and / or isoparaffins.

[0128] Preferably, vegetable oil triglycerides, benzyl benzoate or isopropyl myristate are used as the solvent to provide the internal non-aqueous phase.Most preferred are vegetable oils selected from the group consisting of palm oil, soybean oil, canola oil, sunflower oil, palm seed oil, cottonseed oil, peanut oil, corn germ oil, coconut oil, olive oil, sesame oil, linseed oil, safflower oil, modified vegetable oils, and mixtures thereof.

[0129] The aforementioned solvents may be used individually or as a mixture of two or more solvents in the process according to the invention.

[0130] In another preferred variant of the process according to the invention, at least one polyisocyanate is dissolved directly in a solution of at least one active ingredient, preferably one or more fragrance or fragrance substances / substances or perfume oils, so that, as mentioned above, the core of the microcapsules according to the invention is essentially free of solvent. Avoiding solvents in the microcapsule core is advantageous in terms of reducing production costs and addressing environmental issues.

[0131] In particular, the fragrance or scent is dissolved in a solvent commonly used in the perfume or fragrance industry. The solvent is preferably not alcohol, since alcohol reacts with isocyanates. Examples of suitable solvents include diethyl phthalate, isopropyl myristate, Abalyn® (a colophony resin available from Eastman), benzyl benzoate, ethyl citrate, limonene or other terpenes or isoparaffins. Preferably, the solvent is highly hydrophobic. Preferably, the fragrance or scent solution contains less than 30% solvent. More preferably, the fragrance or scent solution contains less than 20%, and even more preferably less than 10%, of solvent, all percentages being defined by weight relative to the total weight of the fragrance or scent solution. Most preferably, the fragrance or scent is substantially free of solvent.

[0132] If at least one hydrophobic active ingredient is already mixed with a solvent or solvent mixture, the use of an inert solvent or solvent mixture is not necessary. In such cases, at least one first crosslinker can be mixed directly with the hydrophobic active ingredient to obtain an internal non-aqueous phase.

[0133] Essentially, any material suitable for inclusion in microcapsules can be considered in the process of the present invention as the active ingredient to be encapsulated or as the core material for preparing the microcapsules of the present invention.Preferably, hydrophobic, i.e., water-insoluble or water-immiscible liquid or solid, as well as suspension, can be considered as the active ingredient to be encapsulated.These are mainly non-polar substances.Such hydrophobic substances are almost always lipophilic, i.e., they dissolve well in fats and oils.

[0134] In the present context, core materials are hydrophobic active substances, i.e. substances that have a particular effect or cause a particular reaction, such as drugs, insecticides, cosmetic active ingredients, food active ingredients, etc.

[0135] At least one active ingredient to be encapsulated in the process of the present invention is a hydrophobic or lipophilic active ingredient. This ensures that the active ingredient to be encapsulated is in the internal non-aqueous phase during the preparation of the microcapsules of the present invention and does not mix with the external aqueous phase; otherwise, an emulsion would not be formed and deposition of the capsule wall material would not occur on the droplet surface. This allows the lipophilic drug to be completely encapsulated in the microcapsules as the core material during the subsequent emulsification and crosslinking of the capsule wall components. The internal non-aqueous phase thus formed is characterized by its organic hydrophobicity and oiliness.

[0136] In a particularly preferred variant of the invention, the at least one lipophilic or hydrophobic active ingredient is, in particular, a lipophilic or hydrophobic fragrance or scent substance, or a lipophilic or hydrophobic perfume oil or scent (fragrance or scent mixture), a cooling agent, a TRPV1 or TRPV3 modulator, a substance which produces a pungent taste or a warming or burning sensation on the skin or mucous membranes, or a substance which produces a tingling sensation in the mouth or throat, or an active ingredient with an astringent effect, a substance from the group of insecticides, biocides, pesticides, repellents, food additives, cosmetic active ingredients, active pharmaceutical ingredients, dyes, dye precursors; agricultural chemicals, dyes, luminescent paints, optical brighteners, solvents, waxes, silicone oils, lubricants, printing coatings for paper, or a mixture of two or more of the aforementioned active ingredients.

[0137] In a preferred variant of the invention, the hydrophobic or lipophilic active ingredients include, in particular, hydrophobic fragrances or fragrance mixtures of two or more fragrances (fragrance oils) or hydrophobic fragrances or fragrance mixtures of two or more fragrances (flavors), or also biological components.

[0138] In a preferred embodiment according to the first and / or second aspect of the invention, the microcapsules have a core material in the form of a hydrophobic single fragrance or single odorant, the core material being selected from the following groups: extracts of natural raw materials and fractions thereof or components isolated therefrom; single fragrance substances from the group of hydrocarbons; aliphatic alcohols; aliphatic aldehydes and acetals; aliphatic ketones and oximes; aliphatic sulfur-containing compounds; aliphatic nitriles; esters of aliphatic carboxylic acids; formates, acetates, propionates, isobutyrates, butyrates, isovalerates, pentanoates, hexanoates, crotonates, tiglinates and 3-methyl-2-butenoates of acyclic terpene alcohols; acyclic terpene aldehydes and ketones and their dimethyl and diethyl acetals; formates, acetates, propionates of cyclic terpene alcohols. , isobutyrate, butyrate, isovalerate, pentanoate, hexanoate, crotonate, tiglinate and 3-methyl-2-butenoate; cyclic terpene aldehydes and ketones; cyclic and alicyclic ethers; cyclic and macrocyclic ketones; alicyclic aldehydes; alicyclic ketones; esters of cyclic alcohols; esters of alicyclic carboxylic acids; aromatic hydrocarbons; araliphatic alcohols; esters of araliphatic alcohols and aliphatic carboxylic acids; araliphatic ethers; aromatic and araliphatic aldehydes; aromatic and araliphatic ketones; aromatic and araliphatic carboxylic acids and their esters; nitrogen-containing aromatic compounds; phenyl ethers and phenyl esters; heterocyclic compounds; lactones; and mixtures of the above active ingredients.

[0139] Fragrances and flavorings suitable for the preparation of capsules according to the invention are described in the literature.

[0140] Preferably, the microcapsules according to the invention have a core material in the form of a hydrophobic single fragrance or single scent, respectively, the core material being selected from the group consisting of: - 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: a mixture of 3,4,5,6,6-pentamethyl-3,4-hepten-2-ol and 3,5,6,6-tetramethyl-4-methyleneheptan-2-ol, (E,Z)-2,6-nonadienol, 3,7-dimethyl-7-methoxyoctan-2-ol, 9-decenol, 10-undecenol, 4-methyl-3-decen-5-ol; - Aliphatic aldehydes and their acetals, such as hexenal, 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 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-menthen-8-thiol; - Aliphatic nitriles, such as 2-nonenoic acid nitrile; 2-tridecenoic acid nitrile; 2,12-tridecenoic acid nitrile; 3,7-dimethyl-2,6-octadienoic acid nitrile; 3,7-dimethyl-6-octenoic acid nitrile; - aliphatic carboxylic acids and their esters, such as (E)- and (Z)-3-hexenyl formate; ethyl acetoacetate; isoamyl acetate; hexyl acetate; 3,5,5-trimethylhexyl acetate; 3-methyl-2-butenyl acetate; (E)-2-hexenyl acetate; (E)- and (Z)-3-hexenyl acetate; octyl acetate; 3-octyl acetate; 1-octen-3-yl acetate; ethyl butyrate; butyl butyrate; isoamyl butyrate Hexyl butyrate; (E)- and (Z)-3-hexenyl isobutyrate; Hexyl crotonate; Ethyl isovalerate; Ethyl 2-methylpentanoate; Ethyl hexanoate; Allyl hexanoate; Ethyl heptanoate; Allyl heptanoate; Ethyl octanoate; Ethyl (E,Z)-2,4-decadienoate; Methyl 2-octynate; Methyl 2-nonynate; Allyl 2-isoamyloxyacetate; Methyl 3,7-dimethyl-2,6-octadienoate; - Acyclic terpene alcohols, such as citronellol, geraniol, nerol, linalool, lavanduol, nerolidol, farnesol, tetrahydrolinalool, tetrahydrogeraniol, 2,6-dimethyl-7-octen-2-ol, 2,6-dimethyloctan-2-ol, 2-methyl-6-methylene-7-octen-2-ol, 2,6-dimethyl-5,7-octadien-2-ol, 2,6-dimethyl-3 ,5-Octadien-2-ol; 3,7-dimethyl-4,6-octadien-3-ol; 3,7-dimethyl-1,5,7-octatrien-3-ol; 2,6-dimethyl-2,5,7-octatrien-1-ol; and their formates, acetates, propionates, isobutyrates, butyrates, isovalerates, pentanoates, hexanoates, crotonates, tiglinates, and 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, geranyl acetone, and the dimethyl and diethyl acetals of geranial, neral, and 7-hydroxy-3,7-dimethyloctanal; - Cyclic terpene alcohols, such as menthol, isopulegol, α-terpineol, terpinen-4, menthan-8-ol, menthan-1-ol, menthan-7-ol, borneol, isoborneol, linalool oxide, nopol, cedrol, ambrinol, vetiverol, guaiol, and their formates, acetates, propionates, isobutyrates, butyrates, isovalerates, pentanoates, hexanoates, crotonates, tiglinates, and 3-methyl-2-butenoates. Cyclic terpene aldehydes and ketones, such as menthone; isomenthone; 8-mercaptomenthan-3-one; carvone; camphor; fenchone; α-ionone; β-ionone; α-n-methylionone; β-n-methylionone; α-isomethylionone; β-isomethylionone; α-irone; β-irone; 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;β-Sinensal;Acetylated cedarwood oil (methyl cedryl ketone); - cyclic alcohols, such as 4-tert-butylcyclohexanol; 3,3,5-trimethylcyclohexanol; 3-isocamphylcyclohexanol; 2,6,9-trimethyl-(Z2,Z5,E9)-cyclododecatrien-1-ol; 2-isobutyl-4-methyltetrahydro-2H-pyran-4-ol; alicyclic alcohols, such as 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 From the group of: 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; - cyclic and alicyclic ethers, such as cineole; cedryl methyl ether; cyclododecyl methyl ether; 1,1-dimethoxycyclododecane; (ethoxymethoxy)cyclododecane; α-cedrene epoxide; 3a,6,6,9a-tetramethyldodecahydronaphtho[2,1-b]furan; 3a-ethyl-6,6,9a-trimethyldodecahydronaphtho[2,1-b]furan; 1,5,9-trimethyl-13-oxabicyclo-[10.1.0]trideca-4,8-diene; rose oxide; 2-(2,4-dimethyl-3-cyclohexen-1-yl)-5-methyl-5-(1-methylpropyl)-1,3-dioxane; - Cyclic ketones, such as 4-tert-butylcyclohexanone; 2,2,5-trimethyl-5-pentylcyclopentanone; 2-heptylcyclopentanone; 2-pentylcyclopentanone; 2-hydroxy-3-methyl-2-cyclopenten-1-one; 3-methyl-cis-2-penten-1-yl-2-cyclopenten-1-one; 3-methyl-2-pentyl-2-cyclopenten-1-one; 3-methyl-4-cyclopenten Tadecenone;3-Methyl-5-cyclopentadecenone;3-Methylcyclopentadecanone;4-(1-ethoxyvinyl)-3,3,5,5-tetramethylcyclohexanone;4-tert-pentylcyclohexanone;5-Cyclohexadecen-1-one;6,7-Dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanone;9-Cyclo-heptadecen-1-one;Cyclopentadecanone;Cyclohexadecanone - alicyclic 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; - alicyclic ketones, such as 1-(3,3-dimethylcyclohexyl)-4-penten-1-one; 2,2-dimethyl-1-(2,4-dimethyl-3-cyclohexen-1-yl)-1-propanone; 1-(5,5-dimethyl-1-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 2-tert-butylcyclohexyl acetate; 4-tert-butylcyclohexyl acetate; 2-tert-pentylcyclohexyl acetate; 4-tert-pentylcyclohexyl acetate; decahydro-2-naphthyl acetate; 3-pentyltetrahydro-2H-pyran-4-yl acetate; decahydro-2,5,5,8a-tetramethyl-2- Naphthyl acetate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5 or 6-indenyl acetate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5 or 6-indenyl propionate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5 or 6-indenyl isobutyrate; 4,7-methanooctahydro-5 or 6-indenyl acetate; - Esters of alicyclic carboxylic acids, such as allyl 3-cyclohexylpropionate; allyl cyclohexyloxyacetate; methyl dihydrojasmonate; methyl jasmonate; methyl 2-hexyl-3-oxocyclopentanecarboxylate; ethyl 2-ethyl-6,6-dimethyl-2-cyclohexenecarboxylate; ethyl 2,3,6,6-tetramethyl-2-cyclohexenecarboxylate; ethyl 2-methyl-1,3-dioxolane-2-acetate; - aromatic hydrocarbons, for example styrene and diphenylmethane; - aromatic aliphatic alcohols, such as benzyl alcohol; 1-phenylethyl alcohol; 2-phenylethyl alcohol; 3-phenylpropanol; 2-phenylpropanol; 2-phenoxyethanol; 2,2-dimethyl-3-phenylpropanol; 2,2-dimethyl-3-(3-methylphenyl)propanol; 1,1-dimethyl-2-phenylethyl alcohol; 1,1-dimethyl-3-phenylpropanol; 1-ethyl-1-methyl-3-phenylpropanol; 2-methyl-5-phenylpentanol; 3-methyl-5-phenylpentanol; 3-phenyl-2-propen-1-ol; 4-methoxybenzyl alcohol; 1-(4-isopropylphenyl)ethanol; - Esters of aromatic aliphatic alcohols with 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; - Aromatic aliphatic ethers, such as 2-phenylethyl methyl ether; 2-phenylethyl isoamyl ether; 2-phenylethyl-1-ethoxyethyl ether; phenylacetaldehyde dimethyl acetal; phenylacetaldehyde diethyl acetal; hydratropaldehyde dimethyl acetal; phenylacetaldehyde glycerol acetal; 2,4,6-trimethyl-4-phenyl-1,3-dioxane; 4,4a,5,9b-tetrahydroindeno[1,2-d]-m-dioxine; 4,4a,5,9b-tetrahydro-2,4-dimethylindeno[1,2-d]-m-dioxine; - Aromatic and araliphatic aldehydes, such as benzaldehyde, phenylacetaldehyde, 3-phenylpropanal, hydroatropaldehyde, 4-methylbenzaldehyde, 4-methylphenylacetaldehyde, 3-(4-ethylphenyl)-2,2-dimethylpropanal, 2-methyl-3-(4-isopropylphenyl)propanal, 2-methyl-3-(4-tert-butylphenyl)propanal, 3-(4-tert-butylphenyl)propanal, and cinnamaldehyde. ;α-Butylcinnamaldehyde;α-Amylcinnamaldehyde;α-Hexylcinnamaldehyde;3-Methyl-5-phenylpentanal;4-Methoxybenzaldehyde;4-Hydroxy-3-methoxybenzaldehyde;4-Hydroxy-3-ethoxybenzaldehyde;3,4-Methylene-dioxybenzaldehyde;3,4-Dimethoxybenzaldehyde;2-Methyl-3-(4-methoxyphenyl)propanal;2-Methyl-3-(4-methylenedioxyphenyl)propanal; - Aromatic and araliphatic ketones, such as acetophenone; 4-methylacetophenone; 4-methoxyacetophenone; 4-tert-butyl-2,6-dimethylacetophenone; 4-phenyl-2-butanone; 4-(4-hydroxyphenyl)-2-butanone; 1-(2-naphthalenyl)ethanone; benzophenone; 1,1,2,3,3,6-hexamethyl-5-indanyl methyl ketone; 6-t-butyl-1,1-dimethyl-4-indanyl methyl ketone; 1-[2,3-dihydro-1,1,2,6-tetramethyl-3-(1-methyl-ethyl)-1H-5-indenyl]ethanone; 5',6',7',8'-tetrahydro-3',5',5',6',8',8'-hexamethyl-2-acetonaphthone; Aromatic and araliphatic carboxylic acids and their esters, such as benzoic acid; phenylacetic acid; methyl benzoate; ethyl benzoate; hexyl benzoate; benzyl benzoate; methyl phenyl acetate; ethyl phenyl acetate; geranyl phenyl acetate; phenylethyl phenyl acetate; methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenylethyl cinnamate; cinnamyl cinnamate; allyl phenoxyacetate; methyl salicylate; isoamyl salicylate; hexyl salicylate; cyclohexyl salicylate; cis-3-hexenyl salicylate; benzyl salicylate; phenylethyl salicylate; methyl 2,4-dihydroxy-3,6-dimethylbenzoate; ethyl 3-phenylglycidate; ethyl 3-methyl-3-phenylglycidate; - aromatic compounds containing nitrogen atoms, such as 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-pentenoic acid nitrile; 5-phenyl-3-methylpentenoic acid nitrile; methyl anthranilate; methyl N-methylanthranilate; Schiff base of 7-hydroxy-3,7-dimethyloctanal and methyl anthranilate; 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; isoeugenol; isoeugenol methyl ether; thymol; carvacrol; diphenyl ether; β-naphthyl methyl ether; β-naphthyl ethyl ether; β-naphthyl isobutyl ether; 1,4-dimethoxybenzene; eugenyl acetate; 2-methoxy-4-methylphenol; 2-ethoxy-5-(1-propenyl)phenol; p-cresylphenyl acetate; cyclic compounds, such as those from the group 2,5-dimethyl-4-hydroxy-2H-furan-3-one; 2-ethyl-4-hydroxy-5-methyl-2H-furan-3-one; 3-hydroxy-2-methyl-4H-pyran-4-one; 2-ethyl-3-hydroxy-4H-pyran-4-one; - Lactones, such as 1,4-octanolide; 3-methyl-1,4-octanolide; 1,4-nonanolide; 1,4-decanolide; 8-decen-1,4-olide; 1,4-undecanolide; 1,4-dodecanolide; 1,5-decanolide; 1,5-dodecanolide; 1,15-pentadecanolide; cis- and trans-11-pentadecanolide; cis- and trans-12-pentadecanolide; 1,16-hexadecanolide 9-Hexadecen-1,16-olide; 10-Oxa-1,16-hexadecanolide; 11-Oxa-1,16-hexadecanolide; 12-Oxa-1,16-hexadecanolide; Ethylene 1,12-dodecanedioate; Ethylene 1,13-tridecanedioate; Coumarin; 2,3-Dihydrocoumarin; Octahydrocoumarin; and stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers, epimers of the above substances. The composition comprises at least one single fragrance or single scent selected from one or more of:

[0141] Of the above single fragrances or single odorants that can be encapsulated within the spirit of the present invention, fragrances or odorants having aldehyde, carboxylic acid or ester functional groups are particularly preferred for use.

[0142] The aldehyde fragrances or odorants, including the corresponding acetals and also esters and lactones, belong to the following groups: (i) Aliphatic aldehydes and their acetals; (ii) alicyclic aldehydes; (iii) aromatic or araliphatic aldehydes; (iv) aliphatic, aromatic, or araliphatic esters; and (v) lactones; and mixtures thereof.

[0143] The aforementioned fragrances and odorants having aldehyde, carboxylic acid or ester functional groups, as well as mixtures thereof, belong to the following groups: - Aliphatic aldehydes and their acetals, such as hexenal, 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; - alicyclic 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 as benzaldehyde, phenylacetaldehyde, 3-phenylpropanal, hydroatropaldehyde, 4-methylbenzaldehyde, 4-methylphenylacetaldehyde, 3-(4-ethylphenyl)-2,2-dimethylpropanal, 2-methyl-3-(4-isopropylphenyl)propanal, 2-methyl-3-(4-tert-butylphenyl)propanal, 3-(4-tert-butylphenyl)propanal, and cinnamaldehyde. ;α-Butylcinnamaldehyde;α-Amylcinnamaldehyde;α-Hexylcinnamaldehyde;3-Methyl-5-phenylpentanal;4-Methoxybenzaldehyde;4-Hydroxy-3-methoxybenzaldehyde;4-Hydroxy-3-ethoxybenzaldehyde;3,4-Methylenedioxybenzaldehyde;3,4-Dimethoxybenzaldehyde;2-Methyl-3-(4-methoxyphenyl)propanal;2-Methyl-3-(4-methylenedioxyphenyl)propanal; - aliphatic carboxylic acid esters, such as (E)- and (Z)-3-hexenyl formate; ethyl acetoacetate; isoamyl acetate; hexyl acetate; 3,5,5-trimethylhexyl acetate; 3-methyl-2-butenyl acetate; (E)-2-hexenyl acetate; (E)- and (Z)-3-hexenyl acetate; octyl acetate; 3-octyl acetate; 1-octen-3-yl acetate; ethyl butyrate; butyl butyrate; isoamyl butyrate; hexyl acetate; Xylbutyrate; (E)- and (Z)-3-Hexenyl isobutyrate; Hexyl crotonate; Ethyl isovalerate; Ethyl 2-methylpentanoate; Ethyl hexanoate; Allyl hexanoate; Ethyl heptanoate; Allyl heptanoate; Ethyl octanoate; Ethyl (E,Z)-2,4-decadienoate; Methyl 2-octynate; Methyl 2-nonynate; Allyl 2-isoamyloxyacetate; Methyl 3,7-dimethyl-2,6-octadienoate; - Esters of cyclic alcohols, such as 2-tert-butylcyclohexyl acetate; 4-tert-butylcyclohexyl acetate; 2-tert-pentylcyclohexyl acetate; 4-tert-pentylcyclohexyl acetate; decahydro-2-naphthyl acetate; 3-pentyltetrahydro-2H-pyran-4-yl acetate; decahydro-2,5,5,8a-tetramethyl-2- Naphthyl acetate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5 or 6-indenyl acetate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5 or 6-indenyl propionate; 4,7-methano-3a,4,5,6,7,7a-hexahydro-5 or 6-indenyl isobutyrate; 4,7-methanooctahydro-5 or 6-indenyl acetate; - Esters of aromatic aliphatic alcohols with 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 alicyclic carboxylic acids, such as allyl 3-cyclohexylpropionate; allyl cyclohexyloxyacetate; methyl dihydrojasmonate; methyl jasmonate; methyl 2-hexyl-3-oxocyclopentanecarboxylate; ethyl 2-ethyl-6,6-dimethyl-2-cyclohexenecarboxylate; ethyl 2,3,6,6-tetramethyl-2-cyclohexenecarboxylate; ethyl 2-methyl-1,3-dioxolane-2-acetate; - Aromatic and araliphatic carboxylic acid esters, for example selected from one or more of methyl benzoate, ethyl benzoate, hexyl benzoate, benzyl benzoate, methyl phenyl acetate, ethyl phenyl acetate, geranyl phenyl acetate, phenylethyl phenyl acetate, methyl cinnamate, ethyl cinnamate, benzyl cinnamate, phenylethyl cinnamate, cinnamyl cinnamate, allyl phenoxyacetate, methyl salicylate, isoamyl salicylate, hexyl salicylate, cyclohexyl salicylate, cis-3-hexenyl salicylate, benzyl salicylate, phenylethyl salicylate, methyl 2,4-dihydroxy-3,6-dimethylbenzoate, ethyl 3-phenylglycidate, and ethyl 3-methyl-3-phenylglycidate.

[0144] Below is a list of aldehydes, acetals, esters and lactones together with their trade names, which are particularly preferred as representatives of groups (i) to (v) in the context of the process according to the invention: Aldehydes: 2-Methylpentanal; Aldehyde C12 MNA HM; Aldehyde C4; Aldehyde C5; Aldehyde C6; Aldehyde C7; Aldehyde C8; Aldehyde C9; Aldehyde C10; Aldehyde C11 Iso; Aldehyde C11 MOA PURE; Aldehyde C11 Undecanal; Aldehyde C11 Undecylenic Acid; Aldehyde C12;; Aldehyde C12 MNA; Aldehyde C13; Aldehyde Mandarin; Amyl Cinnamic Aldehyde Alpha; Anisal Aldehyde-O; Anisyl Aldehyde; Benzaldehyde NAT; Bergamal; Boronal; Bourgeonal; Campholenic Aldehyde; Citral; Citronellal HM; Citronellyloxyacetaldehyde; Citryral; Citroylal E HM; Cortex Aldehyde; Cortex Aldehyde 50pct 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; Ethylhexanal; FARENAL®; Florhydral; Gelaldehyde; Helional; Heliopan; Heliotropin; Heptadienal TRANS,TRANS,2-4; Heptenal CIS-4; Heptenal TRANS-2; Hexenal TRANS-2; Hexylcinnamic Aldehyde Alpha; Hydroxyatropic Aldehyde; Hydroxycitronellal; Intrelevenaldehyde SPEC.;Isononyl aldehyde;Isovaleric aldehyde;Lemon aldehyde H&R JS I;Lyrial;Linoral;Lyral;Magental;Mandolinal;Mandolinal 10% IN TEC BHT;Meferanal;MELONAL®;Methodicitronellal;Methylbutyraldehyde;Methylcinnamic aldehyde alpha;Methylphenylpentenal-4,2,2;Methylthiopropanal-3;Methyltridecanal-12 10% VT;Methyl-3-buten-2-al;Methyl-5-phenyl-2-hexen-2-al;Mugenal 50 DPG;Neocyclocitral;Nonadienal;TRANS,CIS-2,6;Nonenal CIS-6;Nonenal TRANS-2;ONCIDAL® 3 / 060251;Pentenal TRANS-2;Pericardehyde;Phenylacetaldehyde;Phenylbutenal TRANS-2,2;Phenylpropylaldehyde;Pinoacetaldehyde;Proferanesal;Propionic aldehyde 2-(p-tolyl);Propionic aldehyde;PS-Iraldein X NEU;Safranal;Salicylic aldehyde FG;Sylviale;Tetrahydrocitral;Tiglic aldehyde-2,2;Tolyl aldehyde PARA FG; Tridecenal TRANS-2; Trifenal; Undecadienal-2,4; Undecenal TRANS-2; Vernalaldehyde; Verticitral; Vertumgal; Vertiprenal; Vetral crude; Cinnamaldehyde NAT.HM; Acetal: Phloropa; Heptanal diethyl acetal; Nonandienal diethyl acetal; Okoumal; Phenylacetaldehyde glycerin acetal; Phenylacetaldehyde dimethyl acetal; Esters: Jasmal; Jacemal; Charismal; TIRAMISONE (registered trademark).

[0145] In a further variant of the process according to the invention, the fragrances can also be encapsulated in the form of a single fragrance as a core material, the core material comprising at least one single fragrance or a mixture thereof as an active ingredient.

[0146] Typical examples of fragrance materials that may be encapsulated in accordance with the present invention include acetophenone; allyl capronate; alpha-ionone; beta-ionone; anisaldehyde; anisyl acetate; anisyl formate; benzaldehyde; benzothiazole; benzyl acetate; benzyl alcohol; benzyl benzoate; butyl butyrate; butyl capronate; butylidenephthalide; carvone; camphene; caryophyllene; cineole; cinnamyl acetate acetate;Citral;Citronellol;Citronellal;Citronellyl acetate;Cyclohexyl acetate;Cymene;Damascone;Delta-decalactone;Diacetyl;Dihydrocoumarin;Dimethylanthranilate;Dodecalactone;Ethoxyethyl acetate;Ethyl butyrate;Ethyl butyrate;Ethyl caprinate;Ethyl capronate;Ethyl crotonate;Ethyl furaneol;Ethyl guaiacol;Ethyl isobutyrate;Ethyl isovaleriane ester; ethyl lactate; ethyl methyl butyrate; ethyl propionate; eucalyptol; eugenol; ethyl heptylate; geraniol; geranyl acetate; methyl dihydrojasmonate (e.g., Hedion®); heliotropin; 2-heptanone; 3-heptanone; 4-heptanone; trans-2-heptenal; cis-4-heptenal; trans-2-hexenal; cis-3-hexenol; trans-2-hexenol hexenoic acid;trans-3-Hexenoic acid;cis-3-Hexenyl acetate;cis-3-Hexenyl capronate;trans-2-Hexenyl capronate;cis-3-Hexenyl formate;p-Hydroxybenzyl acetone;Isoamyl alcohol;Isoamyl isovalerianate;Isobutyl butyrate;Isobutyraldehyde;Isoeugenol methyl ether;Isopropylmethylthiazole;Lauric acid;Levulinic acid;Linalool;Linalool oxide;Linalyl acetate;Menthol;Mthofuran;Methyl anthranilate;Methyl butanol;Methyl butyric acid;2-Methylbutyl acetate;Methyl capronate;Methyl cinnamate;5-Methylfurfural;3,2,2-Methylcyclopentenolone;6,5,2-Methylheptenone;Methyl jasmonate;2-Methylmethylbutyrate;2-Methyl-2-pentenoic acid;Methylthiobutyrate;3,1-Methylthiohexanol;3-Methylthiohexyl acetate;Nerol;Neryl acetate;trans,trans-2,4-Nonadienal;2,4-Nonadienol;2,6-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 isovalerianate;Propionaldehyde;Propyl butyrate;Pulegone;Pulegol;Sinensal;Sulfurol;Terpinene;Terpineol;Terpinol;8,3-Thiomenthanone;4,4,2-Thiomethylpentanone;Thymol;Delta-undecalactone;Gamma-undecalactone;Valencene;Valeric acid;Vanillin;Acetoin;Ethyl vanillin;Ethyl vanillin isobutyrate (3-ethoxy-4-isobutyryloxybenzaldehyde);2,5-Dimethyl ethyl-4-hydroxy-3(2H)-furanone and its derivatives (preferably homofuraneol (2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone), homofuranol (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-lactones (preferably 4-methyl delta-decalactone; massoilactone; delta-decalactone; tuberolactone); methyl sorbate; divanillin; 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)furanone; 2-hydroxy-3-methyl-2-cyclopentenone; 3-hydroxy-4,5-dimethyl-2(5H)furanone; acetic acid isoamyl ester; butyric acid ethyl ester; butyric acid n-butyl ester; butyric acid isoamyl ester; 3-methylbutyric acid ethyl ester;n-Hexanoic acid ethyl ester;n-Hexanoic acid allyl ester;n-Hexanoic acid-n-butyl ester;n-Octanoic acid ethyl ester;Ethyl 3-methyl-3-phenylglycidate;Ethyl 2-trans-4-cis-decadienoate;4-(p-Hydroxyphenyl)-2-butanone;1,1-Dimethoxy-2,2,5-trimethyl-4-hexane;2,6-Dimethyl-5-heptene-1-al;Pheny Acetaldehyde;2-Methyl-3-(methylthio)furan;2-Methyl-3-furanthiol;Bis(2-methyl-3-furyl)disulfide;Furfuryl mercaptan;Methional;2-Acetyl-2-thiazoline;3-Mercapto-2-pentanone;2,5-Dimethyl-3-furanthiol;2,4,5-Trimethylthiazole;2-Acetylthiazole;2,4-Dimethyl-5-ethylthiazole;2-Acetyl-1-pyrroline;2-Methyl-3-ethylpyrazine;2-Ethyl -3,5-Dimethylpyrazine;2-Ethyl-3,6-dimethylpyrazine;2,3-Diethyl-5-methylpyrazine;3-Isopropyl-2-methoxypyrazine;3-Isobutyl-2-methoxypyrazine;2-Acetylpyrazine;2-Pentylpyridine;(E,E)-2,4-Decadienal;(E,E)-2,4-Nonadienal;(E)-2-Octenal;(E)-2-Nonenal;2-Undecenal;12-Methyltridecanal;1-Penten-3-one;4-Hydroxy-2, 5-dimethyl-3(2H)-furanone; guaiacol; 3-hydroxy-4,5-dimethyl-2(5H)-furanone; 3-hydroxy-4-methyl-5-ethyl-2(5H)-furanone; cinnamaldehyde; cinna alcohol; methyl salicylate; isopulegol; and stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers or epimers of these substances not specifically mentioned herein; and mixtures of the foregoing substances.

[0147] In another embodiment of the present invention, the microcapsules of the present invention use, as the encapsulated active ingredient or core material, a fragrance mixture or perfume oil, respectively, or a scent mixture or scent. These are compositions containing at least one fragrance or one fragrance. Such compositions, particularly fragrance mixtures or perfume oils, preferably contain 2, 3, 4, 5, 6, 7, 8, 9, 10 or more fragrances. The fragrance mixtures or perfume oils, respectively, are preferably extracts from natural raw materials, such as essential oils, concentrated solid fragrances, absolutes, resins, resinous substances, balsams, and tinctures, such as ambergris oil, amyris oil, angelica seed oil, angelica root oil, anise oil, valerian oil, basil oil, watercress absolute, bay oil, artemisia oil, benzoin resin, bergamot oil, beeswax absolute, birch tar oil, bitter almond oil, savory oil, etc. Budweis leaf oil; Cabreva oil; Cade oil; Calamus oil; Camphor oil; Cananga oil; Cardamom oil; Cascarilla oil; Cassia oil; Cassi absolute; Sea lion absolute; Thuja occidentalis oil; Cedarwood oil; Citrus oil; Citronella oil; Citronella oil; Copaiba balsam; Copaiba balsam oil; Coriander oil; Costus root oil; Cumin oil; Cypress oil; Davana oil; Dill herb oil; Dill seed oil; Eau de Blossom absolute; Oakmoss absolute ;Elemi oil;Tarragon oil;Eucalyptus citriodora leaf oil;Eucalyptus oil;Fennel oil;Spruce needle oil;Maple fragrant oil;Maple fragrant resin;Geranium oil;Grapefruit oil;Guaiac wood oil;Gurjun balsam;Gurjun balsam oil,Helichrysum absolute;Helichrysum oil;Ginger oil;Iris acutum absolute;Iris acutum oil;Jasmine absolute;Iris acutum oil;Blue chamomile oil;Roman chamomile oil;Carrot root oil;Casca Lila oil; Pine needle oil; Curly mint oil; Caraway seed oil; Labdanum oil; Labdanum absolute; Labdanum resin; Lavandin absolute; Lavandin oil; Lavender absolute; Lavender oil; Lemongrass oil; Lovage oil; Distilled lime oil; Pressed lime; Linal oil; Litsea cubeba oil; Bay leaf oil; Mace oil; Marjoram oil; Mandarin oil; Masso bark oil; Mimosa absolute; Musk grain oil; Musk tincture; Muscat oil;Myrrh absolute; Myrrh oil; Myrrh oil; Clove leaf oil; Clove flower oil; Neroli oil; Olibanum absolute; Olibanum oil; Opopanax oil; Orange flower absolute; Orange oil; Origanum oil; Palmarosa oil; Patchouli oil; Perilla oil; Balsam of Peru oil; Parsley leaf oil; Parsley seed oil; Petitgrain oil; Peppermint oil; Pepper oil; Allspice oil; Pine oil; Poultry oil; Rose absolute; Rosewood oil; Rose oil; Rosemary oil; Sage oil Dalmatia; Sage oil Spanish; Sandalwood oil; Se Selected from the group consisting of: loli seed oil; spicy lavender oil; star anise oil; styrax oil; marigold oil; fir needle oil; tea tree oil; turpentine; thyme oil; tolu balsam; tonka absolute; tuberose absolute; vanilla extract; violet leaf absolute; bijou cherry oil; vetiver oil; juniper berry oil; wine yeast oil; mugwort oil; wintergreen oil; ylang oil; hyssop oil; civet absolute; cinnamon leaf oil; cinnamon bark oil; and fractions thereof or components isolated therefrom.

[0148] Most preferably used in the process according to the invention are Agrumex LC; Aglunitrile; Aldehyde C11 Undecylenic Acid; Aldehyde C12 Lauric Acid; Aldehyde C12 MNA; Aldehyde C14 SOG; Aldehyde C16 SOG; Allyl Amyl Glycolate; Allyl Capronate; Allyl Cyclohexyl Propionate; Allyl Heptylate; AMBROCENIDE® 10 TEC; AMBROCENIDE® KRIST 10% IPM; Ambroxide; Anethole Nat. EX Sternanis; Anisaldehyde Pure; APRIFLOREN®; Benzyl Acetone; Benzyl Salicylate; Borneol L / Isoborneol 65 / 35; Buccoblaetteroel; Citronellol 950; Clonal; Cyclohexyl Salicylate; Cymol Para SUPRA; Damascone Delta; Dihydromyrcenol; Dimethylbenzylcarbinylbutyrate; Dinascone; Ethylene brassylate; Butyrate-2-ethylmethyl; Ethyl saffronate; Eucalyptol NAT.; Eucalyptus oil 80 / 85%; Eugenol NAT.; FARENAL®; Fennel oil aromatic sweetener NAT.; Filbertone 10% IPM; Filbertone; Floropal; Galbascone; Geraniol 60; GLOBANONE®; Hedion; Herbaflorate; Herbanate; Herbiflorate; Hebiflopropionate; Hexenyl acetate CIS-3; Hexenyl salicylate CIS-3 ;Hexyl acetate;Hexyl acetate;Hexyl isobutyrate;Hexyl salicylate;Isoamyl butyrate;Isobornyl acetate;Isopropyl methylbutyrate-2;Isoraldain 70;Javanol;Camphor DL;Cresol methyl ether P (CR<10PPM);Lemonyl;Ligustral;Lilial;Linalool;Manganate;Melonar;Methylheptine carbonate;Methyloctyne carbonate;Muscenone;Neocyclocitral;Neroline bromeliad;Neroline yara yara CRYST.;Nerolione;Norlinbanol;Orange Noel;Olivon;Ozonyl;Patchouli ENTF.The fragrance or scent substance is selected from the group consisting of: vegetable oil triglycerides; phellandrene fraction EX eucalyptus oil; PHENIRAT®; phenylethyl acetate; rose oxide HIGH CIS; SANDRANOL®; styrene acetate; SULTANENE®; terpine gamma; tetrahydrolinalool; timber silk; triethyl citrate; undecavertol; vertocitral; vertofix; YSAMBER® K, and mixtures of the above active agents.

[0149] Representative cooling agents for use as hydrophobic active ingredients in the preparation of microcapsules according to the present invention include menthol and menthol derivatives (e.g., L-menthol, D-menthol, racemic menthol, isomenthol, neoisomenthol, neomenthol), menthyl ethers (e.g., (1-menthoxy)-2-propanediol, (1-menthoxy)-2-methyl-1,2-propanediol, 1-menthyl methyl ether), menthyl esters (e.g., menthyl formate, menthyl acetate, menthyl isobutyrate, menthyl lactate, L-menthyl lactate), and the like. Menthyl, L-menthyl lactate, D-menthyl lactate, menthyl-(2-methoxy)-acetate, menthyl-(2-methoxyethoxy)-acetate, menthyl pyroglutamate), menthyl carbonates (e.g., menthyl propylene glycol carbonate, menthyl ethylene glycol carbonate, menthyl glycerol carbonate or mixtures thereof), semiesters of menthol with dicarboxylic acids or their derivatives (e.g., monomenthyl succinate, monomenthyl glutarate, monomenthyl malonate, O-menthyl succinate-N, N-(dimethyl)amide, O-menthylsuccinamide), menthanecarboxamides (e.g., menthanecarboxylic acid-N-ethylamide [WS3], N-α-(methanecarbonyl)glycine ethyl ester [WS5], menthanecarboxylic acid-N-(4-cyanophenyl)-amide, menthanecarboxylic acid-N-(alkoxyalkyl)amide), menthone and menthone derivatives (e.g., L-menthone glycerol ketal), 2,3-dimethyl-2-(2-propyl)-butanoic acid derivatives (e.g., 2,3-dimethyl-2-(2-propyl)-butanoic acid-N -methylamide [WS23]), isopulegol or its esters (1-(-)-isopulegol, 1-(-)-isopulegol acetate), menthane derivatives (e.g., p-menthane-3,8-diol), cubebol or synthetic or natural mixtures containing cubebol, pyrrolidone derivatives of cycloalkyldione derivatives (e.g., 3-(methyl)-2-(1-pyrrolidinyl)-2-cyclopenten-1-one) or tetrahydropyrimidin-2-ones (e.g., icilin or related compounds described in WO 2004 / 026840).Other cooling agents include menthol (L-menthol, D-menthol, racemic menthol, isomenthol, neoisomenthol, neomenthol), L-menthyl methyl ether, menthyl formate, menthyl acetate), menthone, isopulegol, L-(-)-isopulegol acetate, and cubebol, which have a cooling effect on the taste. Suitable cooling agents are well known in the art and are described, for example, in U.S. Patent Application Publication No. 2017 / 216802 (A1), U.S. Patent Application Publication No. 2010 / 273887 (A1), EP 2033688 (A2), and EP 1958627 (A2).

[0150] In an alternative embodiment, a TRPV1 or TRPV3 modulator is used as the encapsulated active ingredient or as the core material in the polyurea / polyurethane microcapsules of the present invention. TRPV1 and TRPV3 modulators are known in the prior art and refer to TRP channels (transient receptor potential channels) of the vanilloid (TRPV) subfamily. TRPV1 modulators confer the spicy taste and hot sensation associated with capsaicin and piperine. TRPV3 proteins belong to a family of nonselective cation channels that function in various processes, including thermosensation and vascular control. TRPV3 channels are directly activated by several natural compounds, such as carvacrol, thymol, and eugenol. Several other monoterpenoids that induce a sensation of warmth or are skin sensitizers can also open the channel. Monoterpenoids also induce agonist-specific desensitization of TRPV3 channels in a calcium-independent manner.

[0151] In another variant, the polyurea / polyurethane microcapsules according to the invention use, as the encapsulated active ingredient or as the core material, an active ingredient selected from the group consisting of substances that cause a pungent taste or a heat or burning sensation on the skin or mucous membranes, or a burning sensation in the mouth or throat, or active ingredients that have a pungent, acrid or astringent effect.

[0152] The heat-inducing or irritating active ingredient is preferably paprika powder, chili pepper powder, paprika extract, bell pepper extract, chili pepper extract, ginger root extract, grain of paradise (Aframomum melegueta) extract, paracles (Jambu oleoresin; Spilanthes acmella or Spilanthes oleracea) extract, Japanese pepper (Zanthoxylum piperitum) extract, Kaempferia galanga extract, Alpinia galanga extract, water pepper (Polygonium hydropiper) extracts, capsaicinoids, especially capsaicin, dihydrocapsaicin or nonivamide; gingerols, especially gingerol-[6], gingerol-[8] or gingerol-

[10] ; shogaols, especially shogaol-[6], shogaol-[8] or shogaol-

[10] ; gingeriones, especially gingerion-[6], gingerion-[8] or gingerion-

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

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

[0153] The active ingredient perceived as irritating or acrid is preferably selected from the group consisting of aromatic isothiocyanates, in particular phenylethyl isothiocyanate, allyl isothiocyanate, cyclopropyl isothiocyanate, butyl isothiocyanate, 3-methylthiopropyl isothiocyanate, 4-hydroxybenzyl isothiocyanate, 4-methoxybenzyl isothiocyanate and mixtures thereof.

[0154] The active ingredients causing the tingling sensation (stinging sensation) are 2E,4E-decadienoic acid-N-isobutyramide (trans-pellitrin), in particular those described in WO 2004 / 043906; 2E,4Z-decadienoic acid-N-isobutyramide (cis-pellitrin), in particular those described in WO 2004 / 000787; 2Z,4Z-decadienoic acid-N-isobutyramide; 2Z,4E-decadienoic acid-N-isobutyramide; 2E,4E-decadienoic acid-N-([2S]-2-methylbutyl)amide; 2E,4E-decadienoic acid Acid-N-([2S]-2-methylbutyl)amide;2E,4E-Decadienoic acid-N-([2R]-2-methylbutyramide;2E,4Z-Decadienoic acid-N-(2-methylbutyl)amide;2E,4E-Decadienoic acid-N-piperid (achilleamide);2E,4E-Decadienoic acid-N-piperid (sarmentine);2E-Decenoic acid-N-isobutyramide;3E-Decenoic acid-N-isobutyramide;3E-Nonenoic acid-N-isobutyramide;2E,6Z,8E-Decatrienoic acid-N-isobutyramide Chilamid (Spilanthol);2E,6Z,8E-Decatrienoic acid-N-([2S]-2-methylbutyl)amide (Homospilanthol);2E,6Z,8E-Decatrienoic acid-N-([2R]-2-methylbutyl)amide;2E-Decen-4-ynoic acid-N-isobutyramide;2Z-Decen-4-ynoic acid-N-isobutyramide;2E,6Z,8E,10E-Dodecatetraenoic acid-N-(2-methylpropyl)amide (α-Sanshool);2E,6Z,8E,10E-Dodecatetraenoic acid-N-(2-hydroxy- 2E,6E,8E,10E-Dodecatetraenoic acid-N-(2-hydroxy-2-methylpropyl)amide (γ-hydroxysanshool); 2E,4E,8Z,10E,12E-Tetradecapentaenoic acid-N-(2-hydroxy-2-methylpropyl)amide (γ-hydroxysanshool); 2E,4E,8E,10E,12E-Tetradecapentaenoic acid-N-(2-hydroxy-2-methylpropyl)amide (γ-hydroxyisosanshool);The hydroxybenzoate is selected from the group consisting of 2E,4E,8Z,10E,12E-tetradecapentaenoic acid-N-(2-methyl-2-propenyl)amide (gamma-dehydrosanshool); 2E,4E,8Z,10E,12E-tetradecapentaenoic acid-N-(2-methylpropyl)amide (γ-sanshool); 2E,4E,8Z,11Z-tetradecatetraenoic acid-N-(2-hydroxy-2-methylpropyl)amide (bungeanol); 2E,4E,8Z,11E-tetradecatetraenoic acid-N-(2-hydroxy-2-methylpropyl)amide (isobungeanol); 2E,4E,8Z-tetradecatrienoic acid-N-(2-hydroxy-2-methylpropyl)amide (dihydrobungeanol) and 2E,4E-tetradecadienoic acid-N-(2-hydroxy-2-methylpropyl)amide (tetrahydrobungeanol), and mixtures thereof. ;

[0155] The active ingredient having astringent activity is preferably selected from the group consisting of catechins, such as epicatechin, gallocatechin, epigallocatechin and their respective gallic acid esters, in particular epigallocatechin gallate or epicatechin gallate, their oligomers (procyanidins, proanthocyanidins, prodelphinidins, procyanilins, thearubigenins, theogallins) and their C- and O-glycosides; dihydroflavonoids, such as dihydromyricetin, taxifolin and their C- and O-glycosides; flavonols, such as myricetin, quercetin and their C- and O-glycosides, such as quercetrin, rutin; gallic acid esters of carbohydrates, such as tannins, pentagalloylglucose or their reaction products, such as erigatannin; aluminum salts, such as alum, and mixtures thereof.

[0156] In another variant according to the first and / or second aspect of the invention, the biological component may also be encapsulated as a core material, the core material comprising at least one biological component or a mixture thereof.

[0157] By biological ingredients is meant active ingredients having biological activity, such as tocopherol, tocopherol acetate, tocopherol palmitate, ascorbic acid, carnotine, carnosine, caffeine, (deoxy)ribonucleic acid and fragments thereof, β-glucan, retinol, bisabolol, allantoin, phytantriol, panthenol, AHA acids, amino acids, ceramides, pseudoceramides, essential oils, plant extracts, and vitamin complexes.

[0158] In a further variant of the process according to the invention, materials for printing coatings for paper are also used as the encapsulated active ingredient or as the core material, respectively, as described in U.S. Pat. No. 2,800,457(A), the disclosure of which in this respect is incorporated herein by reference in its entirety.

[0159] The internal non-aqueous phase may contain, for example, 20 to 80 wt.%, preferably 25 to 75 wt.%, and even more preferably 33 to 50 wt.% of the hydrophobic active ingredient to be encapsulated, 0.1 to 5 wt.%, preferably 0.15 to 3.5 wt.%, and even more preferably 0.5 to 2.5 wt.% of a first crosslinker, and additionally up to 100 wt.% of a hydrophobic solvent, based on the total weight of the internal non-aqueous phase.

[0160] Thus, using the process according to the invention it is possible to achieve high loadings of active ingredient in the microcapsules according to the invention.

[0161] In a further step (ii) of the process according to the invention, an external aqueous phase is provided which comprises at least one protein and / or at least one polysaccharide, and optionally at least one protective colloid.

[0162] The preferred solvent for preparing the external aqueous phase is water or a mixture of water and at least one water-miscible organic solvent. Suitable organic solvents include glycerol, 1,2-propanediol, 1,3-propanediol, ethanediol, diethylene glycol, triethylene glycol, and other analogs. However, preferably, the solvent is water.

[0163] According to the invention, the at least one protein is selected from the group consisting of proteinogenic L-amino acids, animal or plant proteins, in particular protein isolates, animal or plant proteins in the form of fractions, partial or complete hydrolysates or intermediates produced by physicochemical processes or by fermentation or enzymatic treatment of proteins, in particular proteins from the group consisting of meat (mammalian, bird, reptile, amphibian, fish), crab, crustacean, mussels, mollusks, insects, eggs, milk, in particular casein and whey, rennet casein, whey protein concentrate 80%, gelatin, algae, cereals, in particular wheat, barley, rye, spelt, gluten, in particular wheat gluten, rapeseed, sunflower, rice, potato, corn, soybean, bean, pea, chickpea, lentil, lupin, peanut, alfalfa, hemp, other edible plants, chitosan, and mixtures thereof.

[0164] Of the above proteins, gelatin, milk protein, whey protein, chickpea protein, and pea protein are particularly preferred.

[0165] The amino acid is a proteinogenic L-amino acid selected from the group consisting of L-alanine, L-arginine, L-asparagine, L-aspartic acid, L-cysteine, L-glutamine, L-glutamic acid, L-glycine, L-histidine, L-isoleucine, L-leucine, L-lysine, L-methionine, L-phenylalanine, L-proline, L-serine, L-threonine, L-tryptophan, L-tyrosine, and L-valine.

[0166] Of the above amino acids, L-glutamine and L-lysine are particularly preferred.

[0167] In a preferred variant, one of the above proteins is used in combination with one or more free L-amino acids. A preferred combination is milk protein and L-glutamine and / or L-lysine. This combination allows both large and small molecules to be incorporated into the network, improving stability. In addition, the amino acids L-glutamine and / or L-lysine can be particularly easily crosslinked by enzymatic crosslinking agents such as transglutaminase.

[0168] The proteins have the advantageous effect of exhibiting emulsifying properties. Their emulsifying properties contribute to emulsion stabilization. Proteins are amphiphilic and surface-active due to a certain degree of structural flexibility and their differently charged regions within the molecule. For example, modifying proteins through physical or chemical modification can alter the secondary and / or tertiary structure of the molecule. Therefore, the emulsifying properties can be influenced by changing the spatial availability of the charged regions of the molecule or by exposing amino acid side chains. Due to these advantageous properties, the process of the present invention can dispense with the use of additional emulsifiers or protective colloids.

[0169] The proportion of the at least one protein in the external aqueous phase is in the range of 0.25 to 5.0 wt.%, preferably 0.5 to 3.0 wt.%, based on the total weight of the external aqueous phase. Most preferably, the at least one protein is used in the range of 1.0 to 1.5 wt.%, based on the total weight of the external aqueous phase.

[0170] According to a preferred variant of the invention, chickpea protein is used as the protein component.

[0171] According to the first and second aspects of the present invention, the at least one polysaccharide is - indigestible fiber and dietary fiber, especially insoluble dietary fiber, in particular cellulose, cellulose derivatives such as hydroxyethyl cellulose, in particular quaternized hydroxyethyl cellulose, carboxymethyl cellulose (CMC) and microcrystalline cellulose (MCC), hemicellulose, lichenin, chitin, chitosan, lignin, xanthan, vegetable fiber, in particular cereal fiber, potato fiber, apple fiber, citrus fiber, bamboo fiber, sugar beet extract fiber; oat fiber and soluble dietary fiber, in particular inulin, in particular native inulin, highly soluble inulin, granular inulin, high-performance inulin, pectin, alginate, agar, carrageenan, gum arabic (Senegal type, seyal type), konjac gum, gellan gum, curdlan (paramylon), guar gum, locust bean gum, xanthan gum, raffinose, xylose, polydextrose, and lactulose; starches, in particular starches from wheat, potato, corn, rice, tapioca and oats, modified starches and starch derivatives, such as dextrins or maltodextrins, in particular dextrins and maltodextrins from wheat, potato, corn, rice, pea, chickpea and oat, in particular maltodextrins DE8-10, DE17-20, DE18-20, cyclodextrins, oligosaccharides, in particular oligofructose; and sugar alcohols, in particular sorbitol, mannitol, isomalt, maltitol, maltilol syrup, lactitol, xylitol, erythritol; - Glucose and mixtures of two or more of the above polysaccharides. is selected from the group consisting of:

[0172] Of the above polysaccharides, gum arabic and maltodextrin are particularly preferred. Most preferred are maltodextrins DE8-10 potato; DE17-20 corn; DE17-20 potato and DE18-20 wheat.

[0173] Furthermore, dextrins, especially those derived from pea starch, are also preferred, especially for the preparation of chickpea-based microcapsules. However, any polysaccharide may be used for the preparation of chickpea-based microcapsules according to the invention.

[0174] The proportion of the at least one polysaccharide in the external aqueous phase is in the range of 0.5 to 7.0 wt.%, preferably in the range of 1.5 to 6.0 wt.%, based on the total weight of the external aqueous phase. Most preferably, the at least one polysaccharide is used in the range of 3.0 to 5.0 wt.%, based on the total weight of the external aqueous phase.

[0175] Preferably, the external aqueous phase contains both of the main components of the capsule shell, i.e., at least one protein and at least one polysaccharide. When a protein and a polysaccharide are used in combination, a soluble or insoluble protein-polysaccharide complex is formed. The emulsion thus formed is less likely to form aggregates, so the process according to the present invention does not require the addition of protective colloids or additional emulsifiers.

[0176] According to an alternative variant, the external aqueous phase comprises at least one protective colloid and the protein building blocks and / or polysaccharide building blocks are added after emulsification.

[0177] The following combinations of proteins and polysaccharides are particularly preferred for constructing the capsule wall or capsule shell: chickpea protein and dextrin (preferably from pea starch); whey protein and maltodextrin; milk protein and maltodextrin; whey protein and gum arabic; gelatin and maltodextrin; milk protein, L-glutamine, L-lysine, and maltodextrin; and gelatin, milk protein, and maltodextrin.

[0178] The most preferred materials for constructing the capsule shell are gelatin in combination with potato maltodextrin DE8-10, or milk protein, L-glutamine, and / or L-lysine in combination with maltodextrin. Microcapsules prepared using such capsule shell materials result in microcapsules with a free oil content of ≦1% in isopropanol.

[0179] According to another embodiment, the capsule wall comprises chickpea protein as the protein building block and dextrin (preferably derived from pea starch) as the polysaccharide building block. Surprisingly, it has been found that such microcapsules exhibit excellent encapsulation and release properties, enabling efficient encapsulation and targeted release of active ingredients. Additionally, such microcapsules exhibit excellent storage properties, with an extended shelf life of more than one year, without any deterioration in product properties, such as encapsulation efficiency or release properties. Chickpea dextrin-based microcapsules can efficiently encapsulate active ingredients for long periods of time and efficiently inhibit leakage / evaporation of volatile active ingredients, such as aroma substances (see Figures 12a and 12b).

[0180] In an alternative variant thereof, maltodextrin is used as the polysaccharide component for the preparation of microcapsules.

[0181] Preferably, for the chickpea-based microcapsules described above, a combination of aliphatic and aromatic polyisocyanates is used as the crosslinking agent, and even more preferably, a combination of aliphatic and aromatic polyisocyanates in a molar ratio of about 80:20 is used.

[0182] Furthermore, in the case of the latter microcapsules, it is preferred not to add any additional cross-linking agents or protein and / or polysaccharide components.

[0183] The components described and exemplified above for constructing the capsule wall, proteins and polymers are readily available from biological sources. Moreover, they are readily biodegradable as such.

[0184] In an alternative variant of the process according to the invention, the external aqueous phase provides only one of the main components of the capsule shell, protein or polysaccharide, in which the addition of the other main component, polysaccharide or protein, is optionally carried out after emulsification / dispersion, after the addition of the catalyst in process step (v), in step (iv), before or together with the addition of the catalyst in process step (v).

[0185] By using at least one protein and at least one polysaccharide, the content of crosslinking polyisocyanate in the capsule shell can be reduced, preferably to a maximum isocyanate content of 50 wt. % based on the capsule shell, and even more preferably to a maximum isocyanate content of 20 wt. % based on the capsule shell, compared to state-of-the-art microcapsules having a high polyisocyanate content. By replacing polyisocyanate with protein and / or polysaccharide as components for constructing the capsule wall or capsule shell, the polyisocyanate content in the microcapsules is reduced and the degree of crosslinking is reduced.

[0186] However, surprisingly, as will be shown in the following examples, this lower degree of cross-linking leads to stable microcapsules on the one hand and to microcapsules with better biodegradability on the other hand.

[0187] A protective colloid may optionally be added to the external aqueous phase.

[0188] Protective colloids are polymeric systems that prevent the aggregation (flocculation, coagulation, agglomeration) of emulsified, suspended, or dispersed components in suspensions or dispersions. During solvation, protective colloids bind large amounts of water, producing high viscosities in aqueous solutions depending on their concentration. In the preparation of oil-in-water emulsions, protective colloids attach themselves with their hydrophobic moieties to the primary particles and orient their polar, i.e., hydrophilic, molecular portion toward the aqueous phase. This attachment to the interface reduces the interfacial tension, preventing the aggregation of the primary particles. In addition, this stabilizes the emulsion and promotes the formation of relatively small droplets and, correspondingly, the formation of microcapsules.

[0189] In the process according to the invention, the protective colloid exhibits emulsifying properties in addition to the above-mentioned properties. If the emulsifying properties of the protective colloid, such as carboxymethyl cellulose, acid-modified starch, polyvinyl alcohol, ammonium derivatives of polyvinyl alcohol, polystyrene sulfonate, polyvinyl pyrrolidone, polyvinyl acrylate, etc., are sufficient, this may advantageously allow for the omission of the use of an emulsifier in the downstream emulsification / dispersion step (iii) of the process according to the invention. For example, in the case of chickpea-based microcapsules, polyvinyl alcohol is preferably the only protective colloid added to the aqueous phase.

[0190] The protective colloids used in the process according to the invention are diols, in particular ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, the isomeric butanediols, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-dodecanediol, and polyols, preferably triols, in particular glycerin and its ethoxylated and propoxylated products, trimethylolpropane and its ethoxylated and propoxylated products, polyvinyl alcohol (PVOH) and its derivatives, in particular ammonium- or sulfonate-functionalized polyvinyl alcohols, polyphenols, preferably 1,3,5-trihydroxybenzene, polysaccharides, in particular glucose, starch or chemically, mechanically and / or enzymatically modified starch, cellulose derivatives, such as hydroxyethylcellulose, in particular quaternized hydroxyethylcellulose, and carboxymethylcellulose, - Polyvinylpyrrolidone, vinyl maleate copolymer, sodium lignosulfonate, maleic anhydride / styrene copolymer, ethylene / maleic anhydride copolymer, copolymer of ethylene oxide, propylene oxide and polyethoxylated sorbitol acid ester, sodium dodecyl sulfate, - Animal and vegetable polymers, especially gum arabic (Senegal and Seyal types), proteins, gelatin, olibanum resin, shellac, lignin, chitosan, saponin and mixtures of the above compounds is selected from the group consisting of:

[0191] Starch, especially modified starch, or animal or plant polymers are biodegradable, naturally occurring substances. Therefore, in combination with the polyisocyanates described herein, the present process can provide biobased, biodegradable capsule shells. Therefore, in the process according to the present invention, starch and animal and plant polymers also function as so-called bio-crosslinkers.

[0192] The starch used in the process according to the invention is selected from the group consisting of corn starch, potato starch, rye starch, wheat starch, barley starch, oat starch, rice starch, pea starch, chickpea starch, tapioca starch, and mixtures thereof.

[0193] Preferably, the chemically modified starch is acid-modified starch, alkali-modified starch, oxidized starch, acetylated starch, succinated starch, or octyl succinated starch.

[0194] Preferably, the external aqueous phase contains at least one protective colloid selected from polyvinylpyrrolidone, polyvinyl alcohol, and mixtures thereof. Polyvinylpyrrolidone is particularly preferred. Commercially available standard polyvinylpyrrolidones have molecular weights in the range of about 2,500 to 750,000 g / mol.

[0195] Even more preferably, polyols, polyphenols or starches, especially modified starches, are used as protective colloids. Particularly preferably, polyvinyl alcohol or its ammonium derivatives, 1,3,5-trihydroxybenzene, modified starches or carboxymethylcellulose are used as protective colloids for the preparation of microcapsules according to the invention.

[0196] According to the present invention, combinations of two or more different protective colloids can also be used in the preparation of microcapsules according to the present invention.

[0197] In the process according to the present invention, it has been found that the combination of one of the above-mentioned protective colloids and starch as another protective colloid in the external aqueous phase is particularly advantageous.This combination stabilizes the emulsion due to the large number of functional hydroxyl groups, and on the other hand, favors the reaction between protective colloid and polyisocyanate, thereby shifting the reaction equilibrium of the reaction between protective colloid and polyisocyanate to the product, i.e., polyurethane.In addition, the large number of functional hydroxyl groups in starch allows the formation of particularly significant spatial crosslinks.

[0198] Depending on the number of functional groups and / or size of the protective colloid, the above protective colloids exhibit different reaction rates with the isocyanate group of at least one polyisocyanate.For example, due to its size, glycerin reacts with the isocyanate group more quickly than, for example, starch.Therefore, the crosslinking of the protective colloid by the isocyanate group of the polyisocyanate can be controlled by selecting the protective colloid.

[0199] Particularly advantageous combinations have proven to be those of glycerin with starch or modified starch, or with quaternized hydroxyethylcellulose or gum arabic seyal type, which make use of the aforementioned properties of both protective colloids, namely, on the one hand, the high reactivity of glycerin and, on the other hand, the high number of polymerizable functional groups of the other protective colloid.

[0200] The protective colloids used in the process according to the invention have the dual function of acting on the one hand as protective colloids, thus preventing aggregation of the emulsified, suspended or dispersed components, and stabilising the subsequently formed emulsion, promoting the formation of small droplets and stabilising the microcapsule dispersion that is finally formed.

[0201] Thus, the amount of protective colloid used or the amount of the combination of protective colloids used is in the range of 1 to 6 wt.%, preferably in the range of 2 to 4 wt.%, even more preferably in the range of 2 to 3 wt.%, based on the total weight of the external aqueous phase.

[0202] The external aqueous phase is prepared, preferably under agitation, by sequentially adding the polysaccharide and / or protein and, if necessary, the protective colloid, or vice versa, to the external aqueous phase, or by simultaneously adding the ingredients to the external aqueous phase.

[0203] To improve the solubility of the protein, the pH value of the external aqueous phase is adjusted, if necessary, to a pH value below the isoelectric point of the protein, ie below the isoelectric point of the protein used.

[0204] The isoelectric point is the pH value at which the isoelectric state is reached, i.e., the pH value at which the positive and negative charges are in equilibrium in ampholytes or zwitterions (e.g., amino acids and proteins). This value is a constant property of each amino acid and depends on the pKs value of the functional group. In addition to amino acids, peptides and proteins also have an isoelectric point. At the isoelectric point, amino acids, and therefore proteins, exhibit the lowest water solubility.

[0205] Preferably, the pH of the aqueous phase is adjusted to a pH value in the range of 2.0 to 7.0 as a function of the isoelectric point of the protein used, even more preferably to a pH value in the range of 2.0 to 6.0, most preferably to a slightly acidic pH value in the range of 3.0 to 5.0. Adjusting the pH to a pH value below the isoelectric point, i.e. below the isoelectric point of the protein, has the advantage that at such a pH value the emulsifying properties and solubility of the protein are at their highest.

[0206] The pH value of the external aqueous phase is adjusted by adding an organic acid. For this purpose, an organic acid, such as formic acid or acetic acid, is added to the external aqueous phase before the emulsification step to adjust the pH value to the ranges mentioned above.

[0207] The internal non-aqueous phase, comprising at least one first crosslinker and at least one hydrophobic active ingredient, is emulsified or dispersed in the external aqueous phase in a further process step (iii) to form an oil-in-water emulsion / dispersion.

[0208] Oil-in-water emulsions are prepared by mixing an internal non-aqueous phase with an external aqueous phase, the weight ratio of the internal non-aqueous phase to the external aqueous phase preferably being in the range of 70:30 to 60:40, preferably in the range of 30:70 to 60:40.

[0209] Stabilizers and / or emulsifiers or co-emulsifiers are optionally added to the emulsions or dispersions in the process according to the invention to facilitate the formation of the emulsion or dispersion from the internal non-aqueous phase and the external aqueous phase, to stabilize the emulsion or dispersion formed, respectively, and to prevent separation of the internal non-aqueous phase (oily / organic / hydrophobic) and the external aqueous phase (hydrophilic).

[0210] Preferably, a stabilizer is added to the outer aqueous phase to stabilize the emulsion / dispersion and prevent separation of the inner non-aqueous (oil-based) phase and the outer aqueous phase.

[0211] Preferred stabilizers for preparing polysaccharide and protein-based microcapsules according to the invention are primarily acrylic copolymers containing sulfonate groups. Also suitable are copolymers of acrylamide and acrylic acid, copolymers of alkyl acrylate and N-vinylpyrrolidone, such as LUVISKOL® K15, K30, or K90 (BASF); sodium polycarboxylates, sodium polystyrene sulfonates, vinyl and methyl vinyl ether-maleic anhydride copolymers, and ethylene, isobutylene, or styrene-maleic anhydride copolymers, such as microcrystalline cellulose, diutan gum, xanthan gum, or carboxymethylcellulose, commercially available under the name VIVAPUR®.

[0212] The amount of stabilizer used may be in the range of 0.01 to 10 wt.%, preferably in the range of 0.1 to 3 wt.%, each based on the external aqueous phase.

[0213] If necessary, an emulsifier, preferably an O / W emulsifier, is used in the process according to the invention, which allows a uniform distribution of the oil droplets of the internal non-aqueous phase in the external aqueous phase and stabilizes the emulsion. The same applies when a solid insoluble active ingredient is mixed into the external aqueous phase to stabilize the dispersion thus obtained.

[0214] The addition of an emulsifier is optional, especially when the emulsifying properties of the protein or protective colloid are absent or low, i.e., insufficient. When emulsifying proteins and / or protective colloids are used, the use of an emulsifier can be advantageously omitted in the process according to the invention.

[0215] Suitable emulsifiers include, for example, those from the following group: - adhesion products of 2-30 mol of ethylene oxide and / or 0-5 mol of propylene oxide to linear fatty alcohols having 8-22 C atoms in the alkyl group, to fatty acids having 12-22 C atoms, to alkylphenols having 8-15 C atoms, and to alkylamines having 8-22 carbon atoms in the alkyl radical; - alkyl and / or alkenyl oligoglycosides having 8 to 22 carbon atoms in the alkyl(alkenyl) radical and their ethoxylated analogues; - addition products of 1 to 15 mol of ethylene oxide onto castor oil and / or hydrogenated castor oil; - addition products of 15 to 60 moles of ethylene oxide onto castor oil and / or hydrogenated castor oil; partial esters of glycerin 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 polyglycerin (average degree of self-condensation 2 to 8), polyethylene glycol (molecular weight 400 to 5000), trimethylolpropane, pentaerythritol, sugar alcohols (for example sorbitol), alkyl glucosides (for example methyl glucoside, butyl glucoside, lauryl glucoside) and polyglucosides (for example 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 moles of ethylene oxide, preferably Cremophor®; mixed esters of pentaerythritol, fatty acids, citric acid and fatty alcohols and / or mixed esters of fatty acids containing 6 to 22 carbon atoms, methyl glucose and polyols, preferably glycerin or polyglycerin; - mono-, di- and trialkyl phosphates, as well as mono-, di- and / or tri-PEG-alkyl phosphates and their salts; - Wool wax alcohol; - polysiloxane-polyalkyl-polyether copolymers or corresponding derivatives; - block copolymers, for example, polyethylene glycol-30 dipolyhydroxystearate; polymeric emulsifiers, such as the pemulene grades (TR-1, TR-2) from Goodrich or Cosmedia® SP from Cognis; - non-ionic surfactants from at least one of polyalkylene glycols and glycerin carbonates;

[0216] Typical anionic emulsifiers that can be used in the process according to the invention for preparing 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.

[0217] Furthermore, zwitterionic surfactants can be used as emulsifiers in the process for preparing polysaccharide and protein-based microcapsules according to the present invention. Zwitterionic surfactants are surface-active compounds containing at least one quaternary ammonium group, at least one carboxylate group, and one sulfonate group in the molecule. Particularly suitable zwitterionic surfactants are so-called betaines, such as N-alkyl-N,N-dimethylammonium glycinates, such as cocoalkyldimethylammonium glycinate, N-acylaminopropyl-N,N-dimethylammonium glycinates, such as cocoacylaminopropyldimethylammonium glycinate, and 2-alkyl-3-carboxylmethyl-3-hydroxyethylimidazolines having 8 to 18 carbon atoms in the alkyl or acyl group, respectively, as well as cocoacylaminoethyl hydroxyethylcarboxymethylglycinate. Particularly preferred is the fatty acid amide derivative known by the CTFA name cocamidopropyl betaine.

[0218] Also suitable emulsifiers are amphoteric surfactants. Amphoteric surfactants refer to surface-active compounds that contain at least one free amino group and at least one -COOH or -SO3H group in addition to a C8 / 18 alkyl or acyl group in the molecule and are capable of forming inner salts. Examples of suitable amphoteric surfactants include N-alkylglycines, N-alkylpropionic acids, N-alkylaminobutyric acids, N-alkyliminodipropionic acids, N-hydroxyethyl-N-alkylamidopropylglycines, N-alkyltaurines, N-alkylsarcosines, 2-alkylaminopropionic acids, and alkylaminoacetic acids, each of which has approximately 8 to 18 carbon atoms in the alkyl group. Particularly preferred amphoteric surfactants are N-cocoalkylaminopropionates, cocosacylaminoethyl aminopropionates, and C12 / 18 acylsarcosines.

[0219] Finally, cationic surfactants can also be used as emulsifiers, of which those of the esterquat type, preferably methyl-quaternized difatty acid triethanolamine ester salts, quaternized hydroxyethylcellulose, propylene glycol-modified chitosan and distearyldimethylammonium chloride quaternized with epichlorohydrin (DSDMAC), benzalkonium chloride, benzethonium chloride, cetylalkonium chloride, cetylpyridinium chloride, cetyltrimethylammonium bromide (cetrimonium bromide), dequalinium chloride are particularly preferred.

[0220] The emulsifier 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.

[0221] Emulsion formation (in the case of liquid active ingredients) or dispersion formation (in the case of solid active ingredients), i.e., emulsification or dispersion of an internal non-aqueous or oily phase with an external aqueous or hydrophilic phase, is carried out under high turbulence or high shear, whereby the strength of the turbulence or shear determines the diameter of the resulting microcapsules. Microcapsule preparation can be carried out continuously or discontinuously. As the viscosity of the aqueous phase increases or the viscosity of the oily phase decreases, the capsule size generally decreases.

[0222] The process for preparing polysaccharide and protein microcapsules according to the invention can be carried out, for example, according to the "in-line" technique, whereby the inner non-aqueous phase and the outer aqueous phase are first fed separately to the emulsifying turbine by forced metering pumps and then combined immediately before entering the emulsifying turbine, or are combined in the emulsifying turbine at a throughput rate of 1200-1500 l / h. Additionally, the process for preparing polysaccharide and protein microcapsules according to the invention can also be carried out in conventional dispersing or emulsifying equipment.

[0223] The emulsification or dispersion of the external aqueous phase and the internal non-aqueous phase is carried out for the preparation of microcapsules according to the invention, for example, by means of an emulsifying turbine (IKA Eurostar 20 high speed agitator).

[0224] The emulsification or dispersion process in the process according to the present invention is advantageously carried out at a stirring speed of 1000 rpm to 5000 rpm, preferably 3000 rpm to 4000 rpm, for a period of 30 seconds to 20 minutes, preferably 1 to 4 minutes, and most preferably 1 to 2.5 minutes, until a capsule size of 10 to 50 μm±5 μm is obtained.

[0225] After completion of the emulsification or dispersion step (iii), an oil-in-water emulsion or dispersion exists in which the internal oil phase containing the active ingredient to be encapsulated is finely emulsified or dispersed in the form of droplets in the external aqueous phase.

[0226] In an alternative variant of the process according to the invention, as described above, after the emulsification or dispersion step (iii), the addition of at least one polysaccharide or at least one protein is optionally carried out in step (iv). If the external aqueous phase in process step (ii) is provided with only at least one protein-based component, the addition of at least one polysaccharide is carried out in process step (iv). On the other hand, if the external aqueous phase in process step (ii) contains only at least one polysaccharide-based component, the addition of at least one protein is carried out in process step (iv). By separate addition, multiple layers are formed ("layer by layer"), and the individual layers are crosslinked to each other in the subsequent process step (v). This makes it possible, for example, to control the charge of the emulsion and thus the flocculation stability.

[0227] Alternatively, additional proteins and / or polysaccharides, which are the same as or different from the at least one protein and / or at least one polysaccharide from process step (ii), or which have a different charge or whose charge changes with a change in pH value, can be added in process step (iv) if desired. By adding additional proteins and / or polysaccharides, additional layers ("layer by layer") are built up, and the individual layers are cross-linked to each other in the subsequent process step (v). This results in a denser and more stable network of capsule wall components, resulting in a more stable capsule shell, thereby improving the stability of the microcapsules.

[0228] The further protein and / or further polysaccharide is selected from the group of proteins and / or polysaccharides already defined in detail above for process step (ii). The same applies with respect to the preferred variants or preferred combinations of proteins and / or polysaccharides described herein.

[0229] In the subsequent step (v) of the process according to the invention, a first cross-linking of the capsule shell or capsule wall material is carried out, also with stirring.

[0230] The first crosslinking is carried out after emulsification or dispersion by adding a catalyst to crosslink the aforementioned layers of capsule wall components ("layer by layer") and stabilize the resulting capsule shell. This catalyzes the polymerization reaction between the carboxyl and / or sulfo and / or hydroxyl groups of the polysaccharide and the amino groups of the protein, while the isocyanate groups of the first crosslinker undergo interfacial polymerization at the interface between the external aqueous phase and the dispersed internal phase, i.e., the interface of the emulsified or dispersed oil droplets surrounding the encapsulated active ingredient. Similarly, if a catalyst has already been added to the internal non-aqueous phase, crosslinking similarly occurs after emulsification or dispersion of the non-aqueous and aqueous phases.

[0231] Catalytic cross-linking between the functional groups of at least one polysaccharide and / or at least one protein of the aforementioned layer and the functional groups of the first cross-linking agent forms first cross-linking units or a first cross-linking matrix for the structure of the capsule shell or capsule wall.

[0232] The formation of the first crosslinking units in the process according to the present invention is based on a polyaddition reaction between the polysaccharide and the first crosslinking agent and / or the protein and the first crosslinking agent. This involves the hydroxyl groups of the polysaccharide reacting with the isocyanate groups of the first crosslinking agent to form a polyurethane, and the amino groups of the protein reacting with the isocyanate groups of the first crosslinking agent to form a polyurea. In addition to the polyurethane and polyurea, a soluble or insoluble complex of the protein and polysaccharide is also formed during the first crosslinking step (v), which constitutes the capsule wall matrix or capsule shell.

[0233] The greater the number of cross-linking functional groups in the capsule wall building blocks, the greater the spatial cross-linking, resulting in a denser and more stable capsule shell or capsule wall of the resulting microcapsules. In addition to the number of functional groups, the chain length of the individual capsule wall building blocks also has a significant impact on the mechanical properties, i.e., stability, of the microcapsules: for example, the large number of hydroxyl groups in starch allows for the formation of particularly significant spatial cross-linking; longer chain capsule wall building blocks, such as polyisocyanates, result in the formation of more stable capsule walls.

[0234] With the formation of the first cross-linked matrix or first cross-linking unit, the core material, i.e., the emulsified or dispersed oil droplets with the encapsulated active ingredient, are surrounded at the interface by the outer cross-linked matrix or cross-linking unit, thus creating a capsule wall and making the diffusion of the encapsulated active ingredient more difficult.

[0235] The addition of at least one catalyst to the emulsion or dispersion promotes the cross-linking reaction between the polysaccharide and / or protein and the cross-linking agent, catalyzing the reaction in favor of the formation of a first cross-linked matrix or first cross-linking units.

[0236] The catalyst added in the process according to the present invention is preferably diazabicyclo[2.2.2]octane (DABCO), also known as triethylenediamine (TEDA), a bicyclic tertiary amine. DABCO is commonly used as a catalyst for the production of polyurethane plastics. Tertiary amines with free electron pairs promote the reaction between the isocyanate groups of the first crosslinker and the hydroxyl groups of the polysaccharide.

[0237] In addition to DABCO, catalysts based on bismuth or tin, such as catalysts based on bismuth(II) or bismuth(III) salts, may also be used to catalyze the first crosslink, as described in K.C.Frisch & L.P. Rumao, Catalysis in Isocyanate Reactions, Polymer Reviews, 1970, 5:1, pp. 103-149, DOI: 10.1080 / 15583727008085365, the disclosure of which in this regard is incorporated herein in its entirety.

[0238] According to the present invention, a combination of DABCO with one of the above catalysts is preferred, as such a mixture results in a doubling of reactivity, as described in K.C. Brisch & L.P. Rumao, Catalysis in Isocyanate Reactions, Polymer Reviews, 1970, 5:1, pp. 103-149, DOI: 10.1080 / 15583727008085365, the disclosure of which is incorporated herein in its entirety.

[0239] Surprisingly, it has been found that a combination of DABCO and a bismuth catalyst, such as bismuth neodecanoate, is particularly favorable and results in highly stable microcapsules with excellent performance. In this catalyst combination, the bismuth catalyst is preferably added to the inner non-aqueous phase, and the DABCO catalyst is preferably added to the aqueous phase before emulsification, or to a mixture of the non-aqueous and aqueous phases after emulsification.

[0240] DABCO and the above catalysts preferably catalyze the polyurethane reaction between at least one polymerizable polyisocyanate having two or more isocyanate groups and a diol or polyol in the process according to the invention.

[0241] The amount of catalyst added to the external aqueous phase is in the range of 0.001 to 1 wt.%, preferably 0.02 to 0.75 wt.%, and particularly preferably 0.05 to 0.5 wt.%, based on the total weight of the external aqueous phase. However, if polymerization is slow, the amount of catalyst can be increased.

[0242] The catalyst is added to the emulsion or dispersion with stirring, for example as a solid or in the form of an aqueous solution, preferably in water, in which the catalyst is present in a concentration of 0.5 to 2 mol / l, preferably 1 mol / l.

[0243] The catalyst is added at a stirring speed of 500 rpm to 2000 rpm, preferably 1000 rpm to 1500 rpm, at a temperature in the range of 20°C to 30°C, preferably 22°C to 26°C.

[0244] Even more preferably, process step (v) of the catalytic first crosslinking is carried out by gradually heating the emulsion or dispersion to a temperature in the range of 60° C. to 90° C., preferably to a temperature in the range of 65 to 85° C., most preferably to a temperature in the range of 70 to 80° C. The first crosslinking in the process according to the invention is carried out for a duration of about 30 to 90 minutes, preferably for a duration of 40 to 70 minutes, most preferably for a duration of 60 minutes.

[0245] After the initial cross-linking and formation of the capsule shell or wall, the capsules prepared according to the process of the present invention exist as crude microcapsules in the form of an aqueous dispersion or slurry.

[0246] After crosslinking, the microcapsules in the slurry still have a flexible shell, which is not particularly stable and therefore easily breaks open. For this purpose, the shell is hardened. The hardening in process step (vi) is preferably carried out by gradually raising the temperature of the microcapsule slurry to at least 60°C, preferably to a temperature in the range of 60°C to 65°C, up to the maximum boiling point of the microcapsule slurry. Hardening is usually carried out for at least 3 hours, preferably 4 hours, and most preferably 5 hours. Alternatively, in the case of chickpea protein-based microcapsules, for example, it is beneficial to harden the microcapsules at a temperature of 70°C for 1 hour, followed by increasing the temperature to preferably 80°C (within about 30 minutes) and hardening at 80°C for another hour.

[0247] It is further advantageous to add a substance to the microcapsule slurry for hardening. For this purpose, natural vegetable tanning agents of the tannin type are used, which, from a chemical point of view, are proanthocyanidins found in tropical and subtropical dicotyledonous plants, shrubs, and leaves in particular. Terpenes generally have a molecular weight in the range of 500 to 3000 kDa. A preferred example of a suitable tannin is corigalin. For hardening, an aqueous preparation of tannin is added to the aqueous dispersion containing the crude microcapsules. Typically, the tannin is added in an amount of about 0.1 to about 2 wt.%, preferably about 0.5 to about 1.5 wt.%, based on the microcapsules.

[0248] In an alternative variant of the process according to the invention, further proteins and / or further polysaccharides may optionally be added to the microcapsule slurry in process step (vi) in order to optimise cross-linking of the capsule wall matrix.

[0249] The further protein and / or further polysaccharide is selected from the group of proteins and / or polysaccharides already defined in detail above for process step (ii). The same definitions and preferred embodiments and / or preferred combinations as for the proteins and / or polysaccharides are fully valid for the further protein and / or polysaccharide.

[0250] The further protein and / or further polysaccharide may be the same as or different from the protein and / or polysaccharide of process step (ii), preferably the further protein and / or further polysaccharide is different from the protein and / or polysaccharide of process step (ii).

[0251] The addition of additional proteins and / or additional polysaccharides results in further cross-linking with the first cross-linking agent, contributing to the formation of a particularly dense and stable network of capsule wall building blocks.

[0252] The hardening step (vi) of the process according to the invention is followed by a step of cooling the microcapsule slurry to room temperature and, if necessary, a second cross-linking step of the capsule wall building blocks by adding a second cross-linking agent.

[0253] As the second crosslinking agent for the second crosslinking step, the process according to the invention uses at least one crosslinking agent selected from the group consisting of transglutaminase, peroxidase, secondary plant compounds selected from the group consisting of polyphenols, in particular tannins, gallic acid, ferulic acid, hesperidin, cinnamaldehyde, vanillin, carvacrol, and mixtures of two or more of the aforementioned crosslinking agents, as already described in connection with the first and further crosslinking agents. The same definitions and preferred embodiments as for the first and further crosslinking agents are also fully valid for the second crosslinking agent.

[0254] Among the aforementioned additional cross-linking agents, cinnamaldehyde, tannin and gallic acid are particularly preferred.

[0255] In a preferred variant of the process according to the invention, the second crosslinker is different from the first and further crosslinkers in process step (i).

[0256] The content of the second crosslinker is in the range of 0.1 to 5 wt.%, preferably in the range of 0.15 to 2.5 wt.%, based on the total weight of the non-aqueous phase. Most preferably, the second crosslinker is used in the internal non-aqueous phase in the range of 0.5 to 1 wt.%, based on the total weight of the non-aqueous phase.

[0257] The second crosslinker is added to the emulsion or dispersion with stirring, for example as a solid or in the form of an aqueous solution.

[0258] The second crosslinker is present in the aqueous solution at a concentration of 0.01 to 2 mol / l, preferably 0.1 to 1.5 mol / l, and most preferably 0.5 to 1.0 mol / l. The solution has a pH value of 7 to 14, preferably 12.

[0259] Even more preferably, the second crosslinking in process step (vii) is carried out by gradually heating the emulsion or dispersion to a temperature in the range of 20° C. to 50° C., preferably to a temperature in the range of 30 to 40° C. The second crosslinking in the process according to the invention is carried out for a duration of about 20 minutes to 10 hours, preferably for a duration of 30 minutes to 8 hours.

[0260] To optimize the first cross-linking in process step (v) and / or the second cross-linking in process step (vii) of the process according to the invention, the pH value of the emulsion or dispersion is adjusted, as needed, to a pH value higher or lower than the isoelectric point of the protein used. At pH values ​​lower than the isoelectric point, the net electrostatic charge of the protein is positive; above the isoelectric point, the net charge of the protein becomes negative.

[0261] Preferably, to obtain a positive charge on the protein, the pH is adjusted to a value in the range of pH 2.0 to pH 4.0, more preferably to a value in the range of pH 2.5 to pH 3.5, and most preferably to a pH of 3.0. To obtain a negative charge on the protein, the pH is adjusted to a value in the range of pH 8.0 to pH 12.0, even more preferably to a pH of 9.0 to pH 10.0, and most preferably to a pH of 9.5.

[0262] For this purpose, an organic acid, such as formic acid or acetic acid, or a base, such as sodium hydroxide solution, is added to the emulsion or dispersion to adjust the pH value to the range mentioned above.

[0263] Carrying out the first and / or second crosslinking at a pH value above or below the isoelectric point has the advantage that the charge of the protein is modified, thus allowing electrostatic interactions to have a positive effect on capsule formation. In addition, such modification of proteins has a positive effect on their emulsifying ability.

[0264] During the first and second cross-linking steps, the stirring power is reduced to, for example, a stirring speed of about 800-1200 rpm so as not to immediately re-break the forming microcapsules.

[0265] An important criterion for the usefulness of microcapsules is the weight ratio of core material to capsule wall material: on the one hand, as high a proportion of core material as possible is desired so that the capsules can have the highest possible utility value, but on the other hand, it is necessary that the capsules still have a sufficient proportion of capsule wall material to ensure capsule stability.

[0266] According to the invention, it has been found to be particularly advantageous to design the microcapsules so that they have a weight ratio of core material to capsule wall material of between 50:50 and 90:10, preferably between 70:30 and 80:20.

[0267] After complete hardening, the microcapsules prepared according to the method of the present invention are present as a dispersion in water, also called a microcapsule dispersion or microcapsule slurry, in which form the microcapsules are in principle already sold.

[0268] In order to prevent separation or creaming of such suspensions and thus achieve high storage stability, it has proven advantageous for the suspension to have a viscosity of 12 to 1500 mPas. To obtain the desired viscosity of the suspension, it is preferable to use a thickening agent.

[0269] As thickeners, preferably xanthan gum, diutan gum, carboxymethyl cellulose (CMC), microcrystalline cellulose (MCC) or guar gum are used.

[0270] To improve shelf life, one or more preservatives are optionally added to the microcapsule slurry or the microcapsule slurry is dried.

[0271] As preservatives, preferably used are 1,2-hexanediol, 1,2-octanediol, phenoxyethanol-based products, products from a mixture of 1,2-benzisothiazolin-3-one (2.5%) and 2-methyl-4-isothiazolin-3-one (2.5%), etc.

[0272] Alternatively, for storage purposes, the microcapsule slurry is preferably dried.

[0273] For drying of the microcapsule slurry, processes such as freeze-drying are considered, but reference is made, for example, to spray drying in a fluidized bed. It has proven advantageous to add an additional polysaccharide, preferably a dextrin, in particular maltodextrin, to the suspension at a temperature of about 20 to about 50° C., preferably about 40° C., to support the drying process and protect the capsules during this process. The amount of polysaccharide used can thereby be about 50 to about 150 wt.%, preferably about 80 to about 120 wt.%, based on the capsule mass in the dispersion.

[0274] The spray drying itself can be carried out continuously or batchwise in a conventional spray plant, with an inlet temperature of about 170 to about 200°C, preferably about 180 to 185°C, and an outlet temperature of about 70 to about 80°C, preferably about 72 to 78°C.

[0275] As shown in the following embodiments, catalytic cross-linking of polysaccharides and / or proteins with a first cross-linking agent and optionally a second cross-linking agent introduces large molecules into the capsule shell network, thereby increasing the amount of natural components in the capsule shell or microcapsule slurry and therefore increasing the biodegradability of the capsule shell.

[0276] The process according to the present invention is further characterized by the polymerization and / or crosslinking of proteins and polysaccharides and polyisocyanates as the main components via a specifically catalyzed mechanism, thus enabling the preparation of biodegradable microcapsules based on biocompatible polymers. Unlike most prior art microcapsules, in which polyisocyanates constitute the majority of the capsule shell material, in this case it is the exact opposite: the polyisocyanates no longer function as the main material of the microcapsules according to the present invention, but instead act solely as a crosslinker for the amino acids and other components mentioned above.

[0277] The process according to the invention therefore makes it possible to replace part of the polyisocyanate with biodegradable wall materials such as proteins and / or polysaccharides, thus reducing the polyisocyanate content without causing a loss or deterioration of the functionality of the microcapsules, such as olfactory properties, and positive secondary properties such as high stability, i.e., the ability to retain active ingredients. Microcapsules can therefore be prepared by the process according to the invention which, on the one hand, have excellent functionality and at the same time are easily biodegradable.

[0278] Surprisingly, it has been found that, using the process according to the invention, microcapsules can be prepared with up to 25%, preferably up to 50%, and even more preferably up to 75% less starting material isocyanate, or other microcapsule starting materials of the state of the art, while maintaining the same amount of encapsulated active ingredient, without causing any loss or deterioration in the stability of the resulting microcapsules, as shown in the following embodiments.

[0279] In a second aspect, the present invention relates to microcapsules or microcapsule slurries prepared according to the process of the present invention.

[0280] Biodegradable protein and / or polysaccharide-based microcapsules are (a) a core comprising or consisting of at least one hydrophobic active ingredient; (b) a capsule shell comprising or consisting of at least one polysaccharide and / or at least one protein and at least one first crosslinker crosslinked matrix or unit; and optionally a protective colloid and / or optionally a second crosslinker. The present invention is characterized in that it is composed of or comprises:

[0281] The microcapsules according to the present invention comprise a core surrounded or enclosed by a capsule shell or capsule wall. Any material suitable for encapsulation into a microcapsule can be used as the core material for preparing the microcapsules according to the present invention. Preferably, hydrophobic, i.e., water-insoluble or water-immiscible liquids or solids, as well as suspensions, are considered to be the encapsulated materials.

[0282] In the context of this specification, the core material is, as mentioned above, a hydrophobic active ingredient, i.e., a substance that has a specific effect or causes a specific reaction, such as the above-mentioned drugs, insecticides, cosmetic active ingredients, food active ingredients, etc. The term "hydrophobic active ingredient" means that the active ingredient to be encapsulated is in the internal non-aqueous phase during preparation of the microcapsules and does not mix with the external aqueous phase.

[0283] Polymerization and / or cross-linking of functional groups of proteins and / or polysaccharides with polyisocyanates results in a stable capsule wall of alternating, dense, and therefore stable cross-linked matrices or cross-linked units based on polyureas and polyurethanes, and soluble or insoluble complexes of proteins and polysaccharides.

[0284] In a preferred embodiment, the capsule shell comprises or consists of a cross-linked matrix or cross-linking units from the polymerization and / or cross-linking of at least one protein with a first and optionally a second cross-linking agent, and / or a cross-linked matrix or cross-linking units from the polymerization and / or cross-linking of at least one polysaccharide with a first and optionally a second cross-linking agent.

[0285] The cross-linked matrix or cross-linked units from the polymerization and / or cross-linking of at least one protein with a first and optionally a second cross-linking agent are primarily a polyurea-based network, and the cross-linked matrix or cross-linked units from the polymerization and / or cross-linking of at least one polysaccharide with a first and optionally a second cross-linking agent are primarily a polyurethane-based network and a soluble or insoluble complex of protein and polysaccharide.

[0286] In addition to the polyurea and / or polyurethane formation described above, by-products are formed during the aforementioned crosslinking step due to the reactivity of polyisocyanates, such as ureas, allophanates, biurets, uretidiones, carbodiimides, uretonimines, etc., as described in M.F. Sonnenschein, Introduction to Polyurethane Chemistry, Polyurethanes: Science, Technology, Markets, and Trends, 1st Edition, 2015, John Wiley & Sons, pp. 105-126, the disclosures of each of which are incorporated herein in their entireties. These by-products are part of the capsule shell or capsule wall, respectively.

[0287] By constructing the capsule wall based on several individually defined alternating crosslinked matrices or crosslinking units, particularly stable microcapsules with excellent sensory performance can be prepared while at the same time the shell components can be significantly reduced.

[0288] In addition to the main components listed above, the capsule shell may optionally contain a protective colloid and / or an optional further cross-linking agent.

[0289] In a preferred variant according to the second aspect, the microcapsules according to the invention are in the form of a dispersion or slurry in which the microcapsules are dispersed in an external aqueous phase. The weight percentage of the microcapsules in the dispersion or slurry is about 20 to 60 wt.%, in particular about 25 to 50 wt.%, more preferably about 30 to 35 wt.%.

[0290] The microcapsules prepared according to the process according to the invention can be characterized by the d(0.5) value of their particle size distribution: 50% of the capsules are larger than this value and 50% of the capsules are smaller than this value.

[0291] To determine the particle size distribution, microcapsules of different compositions according to the invention were dispersed in water as part of a dynamic process, and the particle size was then determined by laser diffraction. Depending on the capsule size, the laser beam is refractioned differently, which can be converted into size. For this purpose, Mie theory was used. A MALVERN Mastersizer 3000 was used for particle measurements. The corresponding calculations were based on Mie theory.

[0292] The microcapsules according to the invention are characterized by having a particle size distribution with a d(0.5) value between 18 and 50 μm, preferably between 22 and 30 μm.

[0293] The corresponding particle size distribution of the microcapsules according to the invention is shown in Figures 1a to 1d, as well as in Figure 8: Figure 1a: Symcap B: 20% isocyanate content; whey protein / pectin and maltodextrin; microcapsules according to the invention; Figure 1b: Symcap B: 20% isocyanate content. Milk protein and maltodextrin, additional cross-linker tannin. Microcapsules according to the invention; Figure 1c: Symcap B: 30% isocyanate content; milk protein, L-glutamine, L-lysine, maltodextrin; microcapsule according to the invention; Figure 1d: Symcap B: 20% isocyanate content; gelatin and maltodextrin; microcapsules according to the invention; Figure 1e: Comparison of particle size distribution: microcapsules according to the state of the art, i.e. Symcap G2.1: 100% isocyanate, polyvinyl alcohol and guanidine carbonate; microcapsules according to the invention, i.e. Symcap B: 20% isocyanate, milk protein, tannin. Figure 8: Symcap B: 75% isocyanate content; chickpea protein and dextrin from pea starch; microcapsule according to the invention.

[0294] A direct comparison of microcapsules shows that the process according to the invention makes it possible to achieve microcapsules with the same particle size distribution as state-of-the-art microcapsules.

[0295] Surprisingly, as shown in Figures 2 and 3 and 9, despite the reduced polyisocyanate content in the microcapsule wall, the protein and / or polysaccharide-based microcapsules prepared according to the process of the present invention exhibit stability and a content of unintentionally leaked perfume oil comparable to that of state-of-the-art microcapsules. As shown in Figures 2 and 3, the microcapsules according to the present invention prepared with an additional second crosslinker exhibit comparable, if not better, stability and therefore a lower content of free oil compared to state-of-the-art microcapsules, which may be due to a more efficient encapsulation of odorants in particular.

[0296] In particular, the use of additional crosslinker leads to a significant improvement in stability, especially with a reduction in the isocyanate content, and therefore a lower rate of perfume oil leakage (see samples 7 and 8, samples 3 and 4, 5 and 6 in Figures 2 and 3).

[0297] The use of microcapsules in targeted applications, especially those prepared with additional crosslinkers, also shows comparable stability values ​​compared to state-of-the-art microcapsules, despite the reduced polyisocyanate content (see Figure 5).

[0298] The protein and / or polysaccharide based microcapsules according to the invention also show a significant improvement in sensory performance (aroma release) compared to state-of-the-art capsules, which may be attributed to stable active ingredient encapsulation and associated reduced active ingredient loss. The microcapsules according to the invention show significantly higher sensory intensity when the aroma is released by opening the capsules by mechanical friction or pressure, as shown in Figure 6 and Figures 10a and 10b.

[0299] As the degree of cross-linking, which depends on the cross-linking agent and its concentration, increases, the stability of the microcapsules also increases, but at the same time, the ability to biodegrade the capsule shell decreases. Figure 7 generally shows the correlation between microcapsule stability, performance, and biodegradability as a function of cross-linking degree. For example, if the microcapsules are too stable, fewer microcapsules will break open and release the active ingredient when rubbed or pressed, resulting in decreased performance, such as sensory performance. If the microcapsules are too unstable, they will already be destroyed during use or storage and will not function.

[0300] In the protein- and / or polysaccharide-based microcapsules according to the present invention, the polyisocyanate content can be reduced by up to 75% compared to the polyurea / polyurethane microcapsules of the current state of the art, without causing a loss or reduction in the stability of the encapsulated microcapsules or the amount of active ingredient used. In contrast to the current state of the art microcapsules, the isocyanate no longer serves as the main material of the capsule shell or capsule wall, but instead serves only as a crosslinker for the protein and / or polysaccharide of the capsule shell. Therefore, the absolute polyisocyanate content of the microcapsules described herein represents only 1.5% of the total microcapsules.

[0301] Due to the lower polyisocyanate content in the capsule shell or capsule wall on the one hand, and the use of proteins and / or polysaccharides as capsule wall building blocks on the other hand, the microcapsules according to the invention are more biodegradable than the state-of-the-art capsules. The microcapsules according to the invention exhibit significantly better biodegradability, as shown in the examples below.

[0302] Biodegradability is the ability of organic materials to break down into water, carbon dioxide (CO2), and biomass in the presence of microorganisms or fungi under defined conditions of temperature, oxygen, and moisture after a given time.

[0303] According to OECD 301F, microcapsules are considered readily biodegradable if 60% or more of the wall material has been degraded after 28 days.

[0304] The microcapsules according to the invention have a biodegradability according to OECD 301F of ≧10% after 28 days, preferably ≧50% biodegradability, even more preferably ≧70% biodegradability, most preferably ≧90% biodegradability.

[0305] The combination of starting components allows the microcapsules according to the invention to have sufficient stability (mechanical and diffusional stability during use), high sensory performance, and at the same time excellent biodegradability. At the same time, the composition of the starting components allows the degree of cross-linking to be kept low, which significantly improves the biodegradability of the microcapsules. Thus, the previously valid correlation between sensory performance, high cross-linking, and biodegradability may be broken.

[0306] The biodegradability, good stability and good release capacity of the microcapsules, as well as the possibility of encapsulating a wide range of hydrophobic active ingredients using the microcapsules according to the invention, allow the protein- and polysaccharide-based microcapsules according to the invention to be used in a wide range of applications for aromatization and flavoring.

[0307] Furthermore, the microcapsules according to the invention are universal capsules that can be used to encapsulate a wide range of fragrances or scents according to the state of the art, even fragrances or scents having aldehyde, carboxylic acid or ester functional groups, so that there is no restriction to individual active ingredients.

[0308] Due to their advantageous properties, in particular the stability and targeted release of the active ingredient, and their biodegradability, the microcapsules according to the invention are suitable for a wide range of applications, in particular for use in household products, textile care products, laundry detergents, fabric softeners, cleaning agents, fragrance boosters, scented lotions and fragrance enhancers, cosmetics, personal care products, agricultural products, pharmaceuticals, or print coatings for paper, etc.

[0309] Thus, in another aspect, the present invention relates to the use of biodegradable protein and / or polysaccharide-based microcapsules according to the invention, or dispersions of biodegradable protein and / or polysaccharide-based microcapsules according to the invention, for the preparation of household products, textile care products, laundry detergents, fabric softeners, cleaning agents, fragrance boosters, fragrance lotions and liquid or solid fragrance enhancers, cosmetics, personal care products, agricultural products, pharmaceuticals, or print coatings for paper. The microcapsules according to the invention are particularly suitable for encapsulating hydrophobic fragrances or scents, which can be used in a variety of household and textile care products.

[0310] Finally, the present invention relates to household products, textile care products, laundry detergents, fabric softeners, cleaning agents, fragrance boosters, scented lotions and fragrance enhancers, cosmetics, personal care products, agricultural products, pharmaceuticals, or print coatings for paper, etc., comprising the biodegradable protein and / or polysaccharide based microcapsules according to the present invention or a dispersion of biodegradable protein and / or polysaccharide based microcapsules according to the present invention.

[0311] The proportion of microcapsules in the above-mentioned product is 0.05 to 15 wt.%, preferably 0.2 to 5 wt.%, based on the total weight of the product.

[0312] Example of an embodiment The biodegradable protein and / or polysaccharide-based microcapsules according to the present invention and their advantageous properties will now be described in more detail with reference to the following examples. [Example]

[0313] Free oil content of the microcapsules according to the invention compared to the state of the art microcapsules SYMCAP® G2.1 and SYMCAP® G3

[0314] The stability data below refers to testing at 40°C in commercial formulations such as fragrance boosters or fabric softeners.

[0315] In the following examples, microcapsules according to the state of the art were selected whose capsule walls were based exclusively on polyurea networks (samples 1 and 2). The polyisocyanate used was a mixture of hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in a ratio of 80:20. Polyvinyl alcohol was used as the protective colloid, and guanidine carbonate was used for crosslinking. Generally, no catalysts were used in the preparation of these capsules, and the synthesis was carried out at a pH value of 9.

[0316] Microcapsules according to the present invention were prepared with two different proteins (Samples 3-10). One was gelatin, and the other was milk protein with the additional amino acids glutamine L and lysine L. The polysaccharide used in both cases was maltodextrin DE8-10. The polyisocyanate used was a mixture of hexamethylene diisocyanate and 4,4'-methyldiphenylene diisocyanate in an 80:20 ratio. DABCO was used as the catalyst. Cinnamaldehyde was used as an additional crosslinker. Sample 11 was prepared using chickpea protein as the protein component and pea starch-derived dextrin as the polysaccharide component; no additional crosslinker was used. The latter sample was prepared using a combination of two different catalysts: DABCO and bismuth neodecanoate. The bismuth catalyst was added to the inner non-aqueous phase, and the DABCO catalyst was added to the mixture after emulsification of the non-aqueous and aqueous phases with the chickpea protein solution and dextrin solution. A mixture of Desmodur® N-3400 and Mondur M flakes in a molar ratio of 80:20 was used as the polyisocyanate component. The chickpea microcapsules were cured at a temperature of 70°C for 1 hour, then the temperature was increased to 80°C (within approximately 30 minutes) and cured at 80°C for an additional hour.

[0317] The perfume oil content in all samples was 35% of the resulting microcapsule slurry, and the perfume oil was mixed with the vegetable oil in a 1:1 ratio.

[0318] The amount of free oil in the isopropanol is measured: a defined amount of microcapsule slurry is mixed with isopropanol, stirred for 30 seconds, and a sample is taken. The sample is then analyzed by GC-MS. The results indicate how much of the encapsulated oil has been transferred to the isopropanol or whether it has not been completely encapsulated, respectively. Therefore, the free oil content provides an indication of whether the process itself is working, i.e., whether the perfume oil has been completely encapsulated and / or whether the capsule shell is stable enough to prevent the perfume oil from bleeding into the isopropanol. In this context, a value of less than 1% is considered to indicate successful encapsulation and a stable capsule shell.

[0319] The free oil content of the microcapsules according to the invention was compared with the free oil content of the state of the art microcapsules SYMCAP® G2.1 (100%) and SYMCAP® G3 (75%).

[0320] The latest conventional microcapsules, i.e. Sample 1: SYMCAP® G2.1: Isocyanate content: 100%; crosslinked with polyvinyl alcohol and guanidine carbonate. Sample 2: SYMCAP® G3: Isocyanate content: 75%; crosslinked with polyvinyl alcohol and guanidine carbonate.

[0321] Microcapsules according to the invention: Sample 3: SYMCAP B: 50% isocyanate content; gelatin and maltodextrin Sample 4: SYMCAP B: 50% sorbitanate content; gelatin and maltodextrin; additional crosslinker gallic acid; Sample 5: SYMCAP B: 30% isocyanate content; gelatin and maltodextrin Sample 6: SYMCAP B: 30% isocyanate content; gelatin and maltodextrin; additional crosslinker cinnamaldehyde; Sample 7: SYMCAP B: 50% isocyanate content; milk protein + L-glutamine + L-lysine and maltodextrin; Sample 8: SYMCAP B: 50% isocyanate content; milk protein + L-glutamine + L-lysine and maltodextrin; additional crosslinker cinnamaldehyde; Sample 9: SYMCAP B: 30% isocyanate content; milk protein + L-glutamine + L-lysine and maltodextrin; Sample 10: SYMCAP B: 30% isocyanate content; milk protein + L-glutamine + L-lysine and maltodextrin; additional crosslinker cinnamaldehyde; Sample 11: SYMCAP B: 75% isocyanate content; chickpea protein + dextrin derived from pea starch

[0322] Since good results were already obtained with an isocyanate content of 50%, an attempt was made to reduce the isocyanate content further and achieve results comparable to state-of-the-art microcapsules by a second crosslinking.

[0323] [Table 1]

[0324] For sample 11, the results are shown in Figures 2 and 3 and Figure 9.

[0325] As can be seen from the above results, the microcapsules according to the present invention with reduced isocyanate content have a nearly comparable free oil fraction compared to the state-of-the-art microcapsules. By cross-linking with an additional cross-linking agent, the stability of the microcapsule wall can be further increased and the free oil content can be further reduced.

[0326] All three microcapsule samples according to the invention had a free oil content of less than 1%, which is an indication of successful encapsulation and a stable capsule shell. [Example]

[0327] Free oil content of microcapsules according to the invention with and without additional cross-linking agent (transglutaminase (TG))

[0328] Microcapsules were prepared with three different proteins: first, gelatin; second, milk protein, and milk protein further mixed with the amino acids L-glutamine and L-lysine. The polysaccharide used in both cases was maltodextrin DE8-10. DABCO was used as the catalyst. Microcapsule samples were prepared without and with another cross-linking agent; transglutaminase (TG) was used as an additional cross-linking agent.

[0329] Free oil content was determined as described in Example 1.

[0330] The results are shown in Figure 4. [Example]

[0331] Microcapsule stability in application

[0332] The stability of microcapsules according to the present invention and of state-of-the-art microcapsules prepared as described above or by similar methods was measured in the target application. Stability tests were carried out using a representative fabric softener (fabric finish) incorporating the microcapsule slurry at 1 wt. % and stored at room temperature and 40°C, respectively. After specified time intervals (24 hours, 1 week, 2 weeks, and 4 weeks of aging), samples were taken therefrom and the stability was measured.

[0333] The latest conventional microcapsules, i.e. Sample 1: SYMCAP® G2.1: Isocyanate content: 100%; Sample 2: SYMCAP® G3: Isocyanate content: 75%;

[0334] Microcapsules according to the invention: Sample 3: Symcap B: 50% isocyanate content, pea protein, dextrin. Sample 4: Symcap B: 50% isocyanate content; gelatin, maltodextrin. Sample 5: Symcap B: 50% isocyanate content, milk protein, amino acids, cross-linker transglutaminase, maltodextrin. Sample 6: Symcap B: 30% isocyanate content; maltodextrin Sample 7: Symcap B: Isocyanate content 30%, gelatin, crosslinker tannin, maltodextrin

[0335] Measurement: Capsule contents were analyzed by headspace GC / MS (SPME-fiber: PDMS-DVB 65 μm sheath).

[0336] analysis: Integration of areas and calculation of stability intervals for each perfume oil compound ΣGC area of ​​all encapsulated components of the sample 100% Capsule stability = 100% ΣGC area of ​​all fragrance components in quantitative standards

[0337] The identification of fragrance ingredients is based on an in-house database as well as an analytical database of commercially available fragrance formulations.

[0338] This will give you the percentage of perfume oil remaining in the capsule. For example, a result of 98% means that 2% of the original amount of perfume oil used is no longer in the capsule.

[0339] The results are shown in Figure 5.

[0340] As can be seen from Figure 5, the use of additional crosslinker shows comparable stability values ​​in application despite the reduced polyisocyanate content. [Example]

[0341] Sensory evaluation of the microcapsules according to the present invention

[0342] For the sensory evaluation, the microcapsules according to the invention were compared with microcapsules according to the state of the art, i.e. microcapsules prepared as described above:

[0343] The latest conventional microcapsules, i.e. Sample 1: SYMCAP® G2.1: Isocyanate content: 100%;

[0344] Microcapsules according to the invention: Sample 2: SYMCAP B: 30% isocyanate content; gelatin and maltodextrin; additional crosslinker tannin; Sample 3: SYMCAP B: 20% isocyanate content; milk protein and maltodextrin; additional crosslinker tannin Sample 4: SYMCAP B: isocyanate content 75%; dextrin from chickpea protein and pea starch (corresponding to sample 11 in Example 1); Balm: Tomcap

[0345] The sensory evaluation was carried out as follows: the above microcapsules were each added to fabric softener (fragrance Tomcap) at a slurry concentration of 0.4 wt.% and then washed. For comparison, capsules were filled with 17.5% perfume oil (+17.5% vegetable oil = 35% total usage) and injected with 0.4% capsule slurry, resulting in an injection of 0.07% perfume oil of pure perfume oil in the fabric softener. 30 g of fabric softener was used for a 2 kg load of laundry containing terry towels. The washing instructions were as follows: the load of laundry containing terry towels (cotton) was placed in the washing machine and the fabric softener was placed in the fabric softener compartment. The wash program "Express20; 900 rpm" was started. The terry towels were then dried overnight at room temperature.

[0346] Sixteen testers rated the fragrance intensity of terry towels after washing against the corresponding level of free perfume oil in the fabric softener in a paired comparison test on a scale of 1 (no odor) to 9 (very strong odor).

[0347] For Sample 4, a corresponding scale ranging from 1 (no odor) to 6 (very strong odor) was applied. The corresponding results are shown in Figure 6 (Samples 1-3) and Figures 1a and 1b (Sample 4), respectively. The microcapsules were aged in the fabric softener formulation for at least one week, preferably 1 week, 2 weeks, and 4 weeks, respectively (marked in the figure as 1-week sample, 2-week sample, etc.). After washing, the towels were divided into two groups and either air-dried by hanging on a clothesline (labeled "line-dried" in the figure) or machine-dried in a dryer (labeled "machine-dried" in the figure). The towels were then labeled accordingly and stored in large plastic bags until testing.

[0348] The fragrance release was performed in three steps. The first step describes the odor of the untreated fabric. The second step describes the odor of the gently rubbed fabric. For this purpose, slight mechanical stress was applied to the fabric by moving the fabric back and forth between the hands several times, breaking the capsules. The third step describes the odor after the capsules were broken by rubbing the fabric vigorously. After each step, the fragrance intensity was evaluated.

[0349] The results of the sensory evaluation for Sample 4 are shown in Figure 6 and Figures 10a and 10b.

[0350] The microcapsules according to the invention have an odor that is virtually as strong, if not stronger, than state-of-the-art microcapsules, and in particular the use of additional cross-linking agents leads to better sensory performance.

[0351] Chickpea protein-based microcapsules (Sample 4) appear to be highly stable and capable of efficiently suppressing the evaporation of volatile aroma components. The significant increase in strength after crumpling and / or scrubbing indicates efficient encapsulation of the aroma materials. Experiments demonstrate that the microcapsules of the present invention (washing machine, dryer) have high mechanical and thermal stability while still allowing targeted release of active ingredients. Furthermore, when incorporated into, for example, consumer product formulations and aged, the microcapsules of the present invention exhibit increased chemical stability, which allows efficient encapsulation of active ingredients and effectively maintains long-term product quality. Thus, the capsules of the present invention enable efficient encapsulation and excellent targeted release of active ingredients. In addition, the microcapsules of the present invention are less affected by the drying process in a dryer than fully synthetic, state-of-the-art microcapsules. Therefore, the bio-based core-shell microcapsules of the present invention are highly suitable for incorporation into various consumer product formulations. While non-encapsulated free fragrance oils rapidly evaporated and became imperceptible after the drying process and storage, the bio-based microcapsules of the present invention enabled stable encapsulation of fragrance materials and exhibited excellent targeted release behavior, resulting in highly perceptible fragrance intensity (i.e., high sensory performance). Even after 4 weeks of aging in the fabric softener, efficient encapsulation of fragrance materials was observed based on efficient fragrance release and its high intensity, indicating the high stability of the core-shell microcapsules of the present invention within the fabric softener and, therefore, within the consumer product formulation (see Figures 11a and 11b).

[0352] The advantage here is due to the stability of the microcapsules according to the invention: they exhibit comparable stability even with a 30% reduction in isocyanate, based on the capsule shell.

[0353] Due to the above-mentioned advantageous properties, a consistent quality and therefore also sensory stability can be expected over time with the microcapsules according to the invention compared to the microcapsules of the state of the art, which, on the other hand, are less degradable than the microcapsules according to the invention. [Example]

[0354] Biodegradability of the microcapsules according to the present invention

[0355] Biodegradability according to OECD 301F was determined as follows: Degradability of wall material without pre-adaptation of inoculum, measured by manometric respiration (oxygen consumption).

[0356] [Table 2]

[0357] As the amount of isocyanate (crosslinker) decreases, biodegradability increases. [Example]

[0358] Sensory evaluation of the microcapsules according to the invention depending on the catalyst system and shelf life

[0359] In another example, the encapsulation efficiency was analyzed depending on the catalyst system used to prepare the microcapsules according to the invention. In addition, the shelf life was also tested.

[0360] The analytical samples were prepared using chickpea protein as the protein component and pea starch-derived dextrin as the polysaccharide component; no additional cross-linking agent was used. The samples were prepared using two different catalysts: DABCO and bismuth neodecanoate (a dual catalyst system), whereby the bismuth catalyst was added to the internal non-aqueous phase, and the DABCO catalyst was added to the mixture after emulsification of the non-aqueous and aqueous phases. The polyisocyanate components were Desmodur® N-3400 and Mondur® N-3400 in an 80:20 molar ratio. A mixture of M flakes was used. The chickpea microcapsules were cured at a temperature of 70°C for 1 hour, then the temperature was increased to 80°C (within about 30 minutes) and cured at 80°C for another hour. In addition, corresponding samples of chickpea-dextrin-microcapsules were prepared, where only one catalyst, either DABCO catalyst or bismuth neodecanoate catalyst, was used for the preparation of the microcapsules.

[0361] Sensory evaluation was performed according to Example 4 above, based on a scale ranging from 1 (no odor) to 6 (very strong odor). The corresponding results are shown in Figures 12a and 12b. The microcapsules were aged in the fabric softener formulation for 1 week (Figure 12a) or 2 weeks (Figure 12b). After washing, the towels were hung on a clothesline to air dry (labeled "Line Dry" in the figures).

[0362] Comparison of the above samples shows that the microcapsules prepared using the dual catalyst system exhibit better strength compared to microcapsules prepared using only one catalyst instead of the dual catalyst system, indicating more efficient encapsulation and / or improved stability of the microcapsules (see Figures 12a and b).

[0363] Additionally, freshly prepared microcapsules (using the dual catalyst system described above) were compared with one-year-old microcapsules (also using the dual catalyst system). The comparison shows that the as-prepared microcapsules exhibit a long shelf life. Even after one year of storage, the microcapsules could be efficiently incorporated into the product formulation (fabric softener) and exhibited excellent stability, encapsulation, and release properties.

Claims

1. (a) a core comprising or consisting of at least one hydrophobic active ingredient; (b) a capsule shell comprising or consisting of a crosslinked matrix or units of at least one polysaccharide and at least one protein and at least one first crosslinker; A biodegradable microcapsule comprising or consisting of: at least a first crosslinker is selected from the group consisting of aliphatic, cycloaliphatic, hydroaromatic, aromatic or heterocyclic polyisocyanates, polyisocyanates having two or more isocyanate groups, their substitution products and mixtures of the foregoing compounds; the at least one polysaccharide is a cellulose derivative selected from cellulose, hydroxyethyl cellulose, quaternized hydroxyethyl cellulose, carboxymethyl cellulose (CMC) and microcrystalline cellulose (MCC), hemicellulose, lichenin, chitin, chitosan, lignin, xanthan, potato fiber, apple fiber, citrus fiber, bamboo fiber, sugar beet extract fiber; oat fiber, inulin, pectin, alginate, agar, carrageenan, konjac gum, curdlan, paramylon, guar gum, locust bean gum, xanthan gum, raffinose, xylose, polydextrose, and lactulose; starches selected from starches derived from wheat, potato, corn, rice, tapioca and oats, and starch derivatives selected from dextrins or maltodextrins, dextrins and maltodextrins derived from wheat, potato, corn, rice and oats, maltodextrins DE8-10, DE17-20, DE18-20, cyclodextrins, oligosaccharides, oligofructose; and sugar alcohols chosen from sorbitol, mannitol, isomalt, maltitol, maltilol syrup, lactitol, xylitol, erythritol; - Gellan, glucose and mixtures of the above polysaccharides. is selected from the at least one protein is selected from the group consisting of mammalian, bird, reptile, amphibian, or fish meat, crab, crustacean, mollusk, insect, egg, milk, whey, whey protein concentrate 80%, algae, wheat, barley, rye, spelt, gluten selected from wheat gluten, rapeseed, sunflower, rice, potato, corn, soybean, bean, pea, chickpea, lentil, lupin, peanut, alfalfa, hemp, chitosan, and mixtures thereof; Biodegradable microcapsules.

2. 10. The biodegradable microcapsules of claim 1, wherein the capsule shell comprises at least one protective colloid and at least one further cross-linking agent.

3. 3. The biodegradable microcapsule of claim 2, wherein the at least one further cross-linking agent is selected from the group consisting of transglutaminase, peroxidase, secondary plant substances selected from the group consisting of tannins, gallic acid, ferulic acid, polyphenols selected from hesperidin, cinnamaldehyde, vanillin, carvacrol, and mixtures of two or more of the foregoing cross-linking agents.

4. 4. The biodegradable microcapsules according to claim 1, wherein the biodegradable microcapsules comprise at least one lipophilic active ingredient, the at least one lipophilic active ingredient being selected from the group consisting of fragrances, aromatic substances, cooling agents, TRPV1 or TRPV3 modulators, substances producing a tingling taste or a warming or burning sensation on the skin or mucous membranes, or substances producing a tingling sensation in the mouth or throat, or active ingredients having an astringent effect, substances from the group of insecticides, biocides, pesticides, repellents, food additives, cosmetic active ingredients, active pharmaceutical ingredients, agricultural chemicals, dyes, colorants, dye precursors; luminescent paints, optical brighteners, solvents, waxes, silicone oils, lubricants, printing coatings for paper, or mixtures of two or more of the aforementioned active ingredients.

5. The protective colloid is: diols chosen from ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, the isomeric butanediols, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-dodecanediol, and polyols, triols (glycerin and its ethoxylated and propoxylated products, trimethylolpropane and its ethoxylated and propoxylated products), polyvinyl alcohol (PVOH) and its derivatives (ammonium or sulfonate functionalized polyvinyl alcohol), polyphenols (1,3,5-trihydroxybenzene), polysaccharides (glucose, starch or chemically, mechanically and / or enzymatically modified starch), cellulose derivatives (hydroxyethylcellulose selected from quaternized hydroxyethylcellulose and carboxymethylcellulose), - polyvinylpyrrolidone, vinyl maleate copolymer, sodium lignosulfonate, maleic anhydride / styrene copolymer, ethylene / maleic anhydride copolymer, copolymers of ethylene oxide, propylene oxide and acid esters of polyethoxylated sorbitol, sodium dodecyl sulfate, - Animal and plant polymers, gum arabic (Senegal and Seyal types), proteins, gelatin, olibanum resin, shellac, lignin, chitosan, saponin and mixtures of the above compounds The biodegradable microcapsules according to claims 2 to 4, selected from the group consisting of:

6. 6. The biodegradable microcapsules of claim 5, wherein the protective colloid is selected from corn starch, potato starch, rye starch, wheat starch, barley starch, oat starch, rice starch, pea starch, chickpea starch, tapioca starch, and mixtures thereof.

7. 7. The biodegradable microcapsule according to claim 2, wherein the protective colloid is selected from polyols and polyphenols, and the protective colloid further comprises starch.

8. 8. The biodegradable microcapsule according to claim 1, further comprising a stabilizer, the stabilizer being an acrylic copolymer having a sulfonate group.

9. 9. Biodegradable microcapsules according to any one of claims 2 to 8, wherein the capsule shell comprises or consists of a cross-linked matrix or cross-linking units from the polymerization and / or cross-linking of at least one protein with the first and optionally at least one further cross-linking agent, and / or a cross-linked matrix or cross-linking units from the polymerization and / or cross-linking of at least one polysaccharide with the first and optionally at least one further cross-linking agent.

10. 10. The biodegradable microcapsule according to claim 1, wherein the weight ratio of the core material to the capsule wall material is from 50:50 to 90:

10.

11. The biodegradable microcapsules according to any one of claims 1 to 10, wherein the particle size distribution (d(0,5) value) of the microcapsules is 18 to 50 µm.

12. A microcapsule slurry comprising the biodegradable microcapsules according to any one of claims 1 to 11.

13. Household products, textile care products, detergents, fabric softeners, cleaning agents, fragrance boosters or liquid or solid fragrance enhancers, cosmetics, personal care products, perfume compositions, agricultural products, 13. Use of microcapsules according to any one of claims 1 to 11 or a microcapsule slurry according to claim 12 for the preparation of a pharmaceutical product or a printing coating for paper.

14. 13. A household product, fabric care product, detergent, fabric softener, cleaning agent, fragrance booster and fragrance enhancer, cosmetic, personal care product, perfume composition, agricultural product, or pharmaceutical product comprising the microcapsules of any one of claims 1 to 11 or the microcapsule slurry of claim 12.

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