Process for the preparation of microcapsules

Abstract

The present invention relates to a process for the preparation of biodegradable microcapsules, in particular biodegradable protein- and / or polysaccharide-based microcapsules, comprising at least one hydrophobic active substance, and dispersions (microcapsule slurries) of said microcapsules. Furthermore, the present invention relates to biodegradable microcapsules obtained according to the process of the present invention. In another aspect, the present invention relates to the use of said microcapsules and dispersions as constituent ingredients of consumer products.

Description

Technical Field

[0001] This invention relates to a method for preparing biodegradable microcapsules, particularly biodegradable protein and / or polysaccharide-based microcapsules, and dispersions (microcapsule slurries) of such microcapsules containing at least one hydrophobic active substance, preferably polysaccharide and protein-based microcapsules containing fragrances or flavorings, which, compared to prior art microcapsules, offer a balance in biodegradability, stability, and performance. Furthermore, this invention relates to biodegradable microcapsules comprising at least one hydrophobic active substance obtainable according to the method of this invention. On another front, this invention relates to the use of said microcapsules and dispersions as components in household products, textile care products, detergents, fabric softeners, cleaning agents, fragrance enhancers and aroma in liquid or solid forms, cosmetics, personal care products, fragrance compositions, agricultural products, pharmaceutical products, or paper printing coatings. Finally, this invention relates to consumer products containing such microcapsules or microcapsule dispersions. Background Technology

[0002] Microcapsules are particles consisting of a core and a wall material encapsulating the core. The core can be a solid, liquid, or gaseous substance, encapsulated by a polymerized, dense, permeable, or semi-permeable wall material. During preparation, a polymer formed from the starting components is deposited onto the material to be encapsulated via emulsification and coagulation or interfacial polymerization. The core is also referred to as the inner phase. Names such as outer phase, shell, or encapsulation layer are also used for the wall. Microcapsule diameters typically range from 1 to 1000 μm. Wall thicknesses are typically 0.5 to 150 μm, but can vary from 5 to 10 μm. -9 Up to 5.10 -6 The loading can vary within the range of m. Typically, the loading can be 25 to 95% by weight, but it can also be 1 to 99% by weight.

[0003] Active substances can be encapsulated using suitable wall materials (encapsulation materials) for a variety of reasons:

[0004] - Transforming liquids into a controllable powder form (e.g., coatings of vegetable oils or fats);

[0005] - Time-controlled release of substances (dosage control, storage effects of pharmaceuticals, plant protectants, and fertilizers);

[0006] - Masking flavors, odors, and colors (e.g., flavorings that mask bitterness or spiciness);

[0007] - Protect from light, oxidation, heat, acids or alkalis (such as vitamins, flavorings, etc.);

[0008] - Moisture protection (e.g., hygroscopic salts or minerals);

[0009] - Delay the loss of volatile components (such as flavorings);

[0010] - To prevent premature chemical reactions with other components of the mixture;

[0011] - Better treatment before or during processing (flow characteristics, dust formation);

[0012] - Protect personnel from materials that are harmful to health or cause discomfort (chemicals, concentrated flavorings); or improve solubility / suspension through surface modification.

[0013] Hydrophobic active substances, such as fragrances or flavorings, can be easily incorporated into many different application formulations through encapsulation.

[0014] The contents of microcapsules can be released in a variety of ways, and especially based on one of the mechanisms described below:

[0015] - The capsule is mechanically destroyed by crushing or shearing. This mechanism is used, for example, in carbonless copy paper.

[0016] - The capsule is destroyed by melting the wall material. According to this mechanism, for example in baking mixtures, the contents such as foaming agents or flavorings are only released during the baking process.

[0017] - The capsule is broken down by dissolving the wall material. This mechanism is used, for example, in laundry detergent, so that the encapsulated ingredients (such as enzymes) are released only during washing.

[0018] The capsule remains unchanged, and its contents are gradually released through permeation from the capsule wall. Based on this mechanism, for example, a slow and uniform release of the active pharmaceutical ingredient can be achieved in the body.

[0019] Due to their properties, microcapsules are also used in the printing industry, food industry (vitamins, flavorings, plant extracts, enzymes and microorganisms), agricultural chemicals (fertilizers and plant protectants), animal feed industry (minerals, vitamins, enzymes, drugs and microorganisms), pharmaceutical industry, detergent industry and cosmetics industry.

[0020] Today, many everyday consumer products, such as detergents, fabric softeners, laundry powders, liquid detergents, shower gels, shampoos, deodorants, and multi-effect liquids, are scented using fragrances or fragrance blends. Often, fragrances interact with other ingredients in the formula, or volatile components in the fragrance evaporate prematurely. This usually causes the scent impression of the fragrance to change or even disappear completely over time.

[0021] Microencapsulation of these fragrance mixtures offers the possibility of reducing or completely preventing interactions or evaporation of volatile fragrance components in scented products.

[0022] Various capsule wall or encapsulation materials are known to be used in the preparation of microcapsules. Capsule walls can be natural, semi-synthetic, or synthetic materials. Natural shell materials include, for example, gum arabic, agar, agarose, maltodextrin, alginate 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, especially cellulose esters and cellulose ethers, such as cellulose acetate, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, and carboxymethyl cellulose, as well as starch derivatives, especially starch ethers and starch esters. Synthetic shell materials include, for example, polymers such as polyacrylates, polyamides, polyvinyl alcohol, or polyvinylpyrrolidone.

[0023] Depending on the type of capsule wall material and the preparation method, microcapsules with different properties in terms of diameter, particle size distribution, and physical and / or chemical characteristics can be prepared.

[0024] Polyurea microcapsules or polyurea / polyurethane microcapsules, formed by the polymerization of polyisocyanates with polyamines and / or glycols or polyols, are known capsules used in a variety of technical fields, including perfume manufacturing.

[0025] For example, WO 2011 / 161229 or WO 2011 / 160733 describes polyurea microcapsules obtained by reacting two polyisocyanates and a polyamine. 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 a polyurea microcapsule having a polyurea shell comprising the reaction product of a polyisocyanate with guanidine (3,5-diamino-1,2,4-triazole) and an amino acid in the presence of an anionic stabilizer or surfactant (such as anionic polyvinyl alcohol). EP0537467B describes a microcapsule prepared from a polyisocyanate containing polyethylene oxide in the presence of a stabilizer (such as polyvinyl alcohol). According to WO 2007 / 096592, microencapsulation can be carried out in an oil phase that is emulsified in a continuous aqueous phase, which is typically stabilized by a surfactant system (such as polyvinyl alcohol or its carboxylated and sulfonated derivatives).

[0026] The above-described exemplary delivery system from the prior art has both good stability, i.e., the ability to retain active substances and thus the ability of capsules to avoid loss of volatile components, and good performance, such as releasing fragrance in the case of flavoring or aroma capsules.

[0027] However, the disadvantages of the aforementioned microcapsules are that the polymer capsule wall or shell material requires a high polymer content to ensure sufficient stability and prevent excessive loss of active substances. Furthermore, microencapsulation introduces plastics into the environment, where they can act as "microplastics," potentially causing environmental damage or health harm.

[0028] As the environmental impact of plastic pellets draws increasing public criticism and societal pressure to address environmental issues grows, the demand for bio-based and biodegradable solutions is growing. Microcapsules require the development of new materials to reduce microplastics in the environment. In this context, bio-based and biodegradable materials are the focus.

[0029] Against this backdrop, there is a need to provide microcapsules that increasingly utilize biodegradable capsule wall materials in their preparation, while exhibiting outstanding stability and release performance for their respective applications. Importantly, not only is the macromolecular material of the capsule wall itself biocompatible, but each fragment formed during decomposition is also biocompatible.

[0030] However, in the case of microcapsules, the task of reducing the amount of microplastics in the environment using biodegradable materials is not trivial, because the expected functionality of microcapsules, such as olfactory properties, and positive secondary properties, such as high stability and toxicological stability, conflict with the requirement for rapid biodegradation in many applications.

[0031] Preparing microcapsules that exhibit both good stability and good release of active substances is particularly challenging. The ability of the capsule to retain active substances, and thus its ability to prevent the loss of volatile components, depends especially on the stability of the capsule within the product base. However, capsules with particularly good stability do not automatically exhibit good biodegradability.

[0032] As the degree of cross-linking increases, the stability of microcapsules increases, but at the same time, the biodegradability of the capsule shell decreases. For very stable microcapsules, their performance (such as sensory properties) is lower because the number of microcapsules that rupture and release the active substance due to pressure, friction, etc., is reduced. If a microcapsule is very unstable, it will be destroyed during storage and will not exhibit its intended performance.

[0033] Therefore, the composite objective of the present invention is to provide microcapsules that preferably satisfy one, more, or preferably all of the following requirements:

[0034] - Improve biodegradability,

[0035] - It has no toxic effects on humans and the environment;

[0036] - To achieve sufficient stability,

[0037] - Widely applicable to a variety of different active substances to be encapsulated.

[0038] - The encapsulated active ingredients exhibit excellent release properties, and

[0039] - It can be obtained through known methods for preparing microcapsules, and

[0040] - The ingredients are readily available, meaning they can be prepared using bio-based or sustainably produced raw materials.

[0041] A surprising discovery was made: this task can be solved by preparing microcapsules through interfacial polymerization of polysaccharides and / or proteins with cross-linking agents in an aqueous emulsion in the presence of a catalyst. Cross-linking can form biodegradable and stable capsule shells or walls, which can be used to encapsulate a variety of hydrophobic or lipophilic active substances. Summary of the Invention

[0042] The problems raised herein are addressed by the subject matter of the independent claims. Preferred embodiments are derived from the text of the dependent claims and the following description.

[0043] Therefore, the first subject of the present invention relates to a method for preparing biodegradable protein and / or polysaccharide-based microcapsules, the method comprising the following steps in sequence:

[0044] (i) Providing an internal non-aqueous phase comprising at least one first crosslinking agent and at least one hydrophobic active substance, and optionally at least one other crosslinking agent;

[0045] (ii) Provide an external aqueous phase comprising at least one protein and / or at least one polysaccharide and optionally at least one protective colloid, and optionally adjust the pH of the aqueous phase to a pH below the isoelectric point of the protein.

[0046] (iii) Emulsifying or dispersing the internal non-aqueous phase in the external aqueous phase, optionally in the presence of at least one stabilizer and / or at least one emulsifier, to obtain an oil-in-water emulsion / dispersion;

[0047] (iv) Optionally, at least one other polysaccharide and / or at least one other protein may be added;

[0048] (v) A first cross-linking process is performed by adding at least one catalyst to obtain a microcapsule slurry;

[0049] (vi) The microcapsule slurry is solidified at a temperature of at least 60°C, and optionally at least another polysaccharide and / or at least another protein is added;

[0050] (vii) Cooling and, optionally, second crosslinking by adding at least one second crosslinking agent; and

[0051] (viii) Optionally, the microcapsules are separated from the microcapsule slurry, and the microcapsules are dried or the viscosity of the microcapsule slurry is adjusted by adding at least one thickener.

[0052] In a second aspect, the present invention relates to a microcapsule containing at least one lipophilic active substance, or a microcapsule slurry prepared according to the method of the present invention.

[0053] Furthermore, the subject of this invention is to provide a biodegradable microcapsule comprising or consisting of the following:

[0054] (a) A core, which contains or consists of at least one hydrophobic active substance;

[0055] (b) A capsule shell comprising or consisting of: a cross-linking matrix or cross-linking unit composed of at least one polysaccharide and / or at least one protein and at least one first cross-linking agent; and optionally at least one protective colloid and / or optionally at least another cross-linking agent.

[0056] Finally, in another aspect, the present invention relates to the use of microcapsules according to the invention or dispersions containing microcapsules according to the invention in the manufacture of household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance enhancers, fragrance washes or aroma enhancers in liquid or solid form, cosmetics, personal care products, fragrance compositions, agricultural products, pharmaceutical products or paper printing coatings.

[0057] Surprisingly, within the scope of this invention, it has been found that during the preparation of microcapsules, the combination of polysaccharides and / or proteins, and subsequent crosslinking with polyisocyanates having at least two or more isocyanate groups, results in stable microcapsules, thus ensuring the effective encapsulation of lipophilic active substances and the subsequent targeted release of these active substances, while the microcapsules also exhibit good biodegradability due to their bio-based and biodegradable components.

[0058] By using polysaccharides and / or proteins, the content of polyisocyanate polymers in capsule wall or capsule shell materials can be reduced, i.e., replaced with bio-based capsule wall components. Therefore, the content of bio-based capsule wall components is increased without affecting the stability of the microcapsule wall.

[0059] These and other aspects, features, and advantages of the invention will become apparent to those skilled in the art upon studying the following detailed description and claims. Any feature or variation of one aspect of the invention herein may be used or substituted in another aspect of the invention. Furthermore, it is understood that the examples contained herein describe and illustrate the invention, but should not be construed as limiting the invention, and in particular, the invention is not limited to these examples.

[0060] Unless otherwise stated, all percentages are by weight. Examples of figures given in “x to y” format include the given values. When multiple preferred ranges of figures are given in this format, it is understood that all ranges resulting from combining different endpoints are also included.

[0061] The terms “at least one” or “minimum one” or “one or more” as used herein refer to one or more, such as 2, 3, 4, 5, 6, 7, 8, 9 or more.

[0062] The term "and / or" indicates a connection or provides an alternative.

[0063] Numerical examples given in the form of "x to y" include the given values. If multiple preferred numerical ranges are given in this format, all ranges consisting of combinations of different endpoints will also be determined. Attached Figure Description

[0064] Figures 1a-1d The particle size distribution (d(0.5) value) of microcapsules containing different components according to the present invention is shown. Figure 1e A comparison of particle size distributions of microcapsules according to the prior art and microcapsules according to the present invention is shown. The particle size distribution was determined using a Malvern Mastersizer 3000 particle size analyzer. The corresponding calculations are based on Michaelis-Menten theory.

[0065] Figure 2 The free oil content of the microcapsules according to the present invention is shown in comparison with that of prior art microcapsules.

[0066] Figure 3 The free oil content of the microcapsules according to the present invention is shown in comparison with that of prior art microcapsules.

[0067] Figure 4 The free oil content of microcapsules prepared according to the present invention with and without another crosslinking agent is shown.

[0068] Figure 5 The stability of the microcapsules according to the invention in fabric softeners is shown.

[0069] Figure 6Sensory evaluation of the microcapsules according to the present invention is shown.

[0070] Figure 7 This is a schematic diagram illustrating the overall relationship between the stability, performance, and biodegradability of microcapsules and the degree of cross-linking.

[0071] exist Figure 2-6 In Chinese, a dot is used as the decimal point separator. Detailed Implementation

[0072] In a first aspect, the present invention relates to a method for preparing biodegradable protein / polysaccharide-based microcapsules, the method comprising the following steps in sequence:

[0073] (i) Providing an internal non-aqueous phase comprising at least one crosslinking agent and at least one hydrophobic active substance, and optionally at least another crosslinking agent;

[0074] (ii) Provide an external aqueous phase comprising at least one protein and / or at least one polysaccharide and optionally at least one protective colloid, and optionally adjust the pH of the aqueous phase to a pH below the isoelectric point of the protein.

[0075] (iii) Emulsifying or dispersing the internal non-aqueous phase in the external aqueous phase, optionally in the presence of at least one stabilizer and / or at least one emulsifier, to obtain an oil-in-water emulsion / dispersion;

[0076] (iv) Optionally, at least one other polysaccharide and / or at least one other protein may be added;

[0077] (v) A first cross-linking process is performed by adding at least one catalyst to obtain a microcapsule slurry;

[0078] (vi) The microcapsule slurry is solidified at a temperature of at least 60°C, and optionally at least another polysaccharide and / or at least another protein is added;

[0079] (vii) Cooling and, optionally, second crosslinking by adding at least one second crosslinking agent; and

[0080] (viii) Optionally, the microcapsules are separated from the microcapsule slurry, and the microcapsules are dried or the viscosity of the microcapsule slurry is adjusted by adding at least one thickener.

[0081] In the context of this invention, microcapsules should be understood as microparticles having at least one or more active substances as the core material of the capsule and encapsulated by a capsule shell or capsule wall. Preferably, the active substances are hydrophobic or lipophilic. Such active substances are insoluble or sparingly soluble in water, but readily soluble in fats and oils. In this invention, the terms "microcapsule" or "capsule" and "hydrophobic" or "lipophilic" are synonymous.

[0082] Within the scope of this invention, the capsule shell or capsule wall is preferably composed of multiple cross-linking matrices or cross-linking units, which preferably have different compositions, and are generated by multiple method steps or process sequences, particularly cross-linking steps, during the microcapsule preparation process according to the invention. The cross-linking matrix comprises or consists of at least one polysaccharide and / or at least one protein. These capsule wall components are cross-linked through interfacial polymerization using cross-linking agents and catalysts, and cross-linked with each other via targeted catalytic mechanisms, thereby forming a three-dimensional network composed of polysaccharides, proteins, and cross-linking agents.

[0083] In the first step (i) according to the invention, an internal non-aqueous phase is provided, comprising at least one crosslinking agent and at least one hydrophobic active material to be encapsulated, and optionally another crosslinking agent.

[0084] According to the first and / or second aspects of the present invention, the first crosslinking agent for constructing a capsule shell or capsule wall is selected from the group consisting of: polyisocyanates having two or more isocyanate groups, and mixtures of two or more of the above-mentioned first crosslinking agents, wherein the polyisocyanate is selected from the group consisting of: aliphatic, alicyclic, hydrogenated aromatic, aromatic or heterocyclic polyisocyanates and their substituted products.

[0085] At least one isocyanate or a polyisocyanate having two or more isocyanate groups, used in the method of preparing biodegradable protein and / or polysaccharide-based microcapsules according to the present invention, having at least two isocyanate groups, for forming a polymer network by polymerization, the network forming a capsule shell or capsule wall.

[0086] Polyisocyanates are R-substituted organic derivatives (RN=C=O) of isocyanate (HN=C=O). Organic isocyanates are compounds in which an isocyanate group (-N=C=O) is combined with an organic group. Polyfunctional isocyanates or polyisocyanates refer to compounds containing at least two, i.e., 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200 or more isocyanate groups (-N=C=O). Polyisocyanates with two isocyanate groups are also called diisocyanates.

[0087] Polyisocyanates can be classified as aliphatic, alicyclic, hydrogenated aromatic, aromatic, or heterocyclic isocyanates or polyisocyanates. Furthermore, the polyisocyanates according to the present invention can be linear or branched.

[0088] Polyisocyanates, especially aromatic polyisocyanates, are highly reactive compounds. The addition polymerization of polyisocyanates with diols or polyols is the basis of polyurethane chemistry, and the addition polymerization of polyisocyanates with amines is the basis of polyurea chemistry.

[0089] According to the present invention, at least bifunctional, preferably multifunctional, polyisocyanates are used, that is, all aliphatic, alicyclic and aromatic isocyanates are applicable as long as they have at least two active isocyanate groups.

[0090] Particularly preferred are aliphatic, alicyclic, hydrogenated aromatic, aromatic or heterocyclic polyisocyanates and their substituted products, as well as mixtures of the above monomers or oligomers. Among the above polyisocyanates, aliphatic and / or aromatic compounds are preferably used.

[0091] In a preferred embodiment of the method according to the invention, the polyisocyanate contains, on average, 2 to 5 functionalized -N=C=O groups. For example, these include aliphatic, alicyclic, and aromatic diisocyanates, triisocyanates, and higher polyisocyanates. Polyisocyanate).

[0092] Of the aforementioned polyisocyanates, diisocyanates and polyisocyanates having three functional -NC=O groups are preferred and are therefore preferred for use in carrying out the present invention. Preferably, diisocyanates having the general structure O=C=NRN=C=O are used, wherein R represents an aliphatic, alicyclic, or aromatic group. Preferably, these groups have five or more carbon atoms.

[0093] In a preferred embodiment of the method according to the invention, at least one polyisocyanate having two or more isocyanate groups is selected from the group consisting of aliphatic polyisocyanates and / or aromatic polyisocyanates. In a more preferred variant of the method according to the invention, at least one polyisocyanate is a combination of two different aliphatic polyisocyanates, or a combination of aliphatic and aromatic polyisocyanates.

[0094] Due to the increased number of functional groups, optimized cross-linking or networking of the capsule wall is achieved, thereby providing microcapsules with prolonged sustained release of active substances and good stability in consumer products.

[0095] In a preferred variant of the method according to the invention, the polyisocyanate is an aliphatic polyisocyanate.

[0096] The term "aliphatic polyisocyanate" refers to any non-aromatic polyisocyanate molecule. Furthermore, a polyisocyanate molecule contains at least two isocyanate groups, namely 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 carbon atoms of the same aliphatic molecule, as well as derivatives of such compounds.

[0097] Aliphatic polyisocyanate molecules having at least two isocyanate groups, i.e., at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 50, 100, 200 or more isocyanate groups, may also be linear, branched or cyclic, and may have any substitutions, including, for example, aliphatic substituents, aromatic substituents, one or more heteroatoms such as nitrogen, oxygen, phosphorus and / or sulfur, halogens such as fluorine, chlorine, bromine and / or iodine and / or other functional groups such as alkoxy groups.

[0098] Preferably, the straight-chain aliphatic polyisocyanate molecule is selected from C2 to C20 straight-chain alkyl, more preferably C3 to C15 straight-chain alkyl, C4 to C12 straight-chain alkyl, C5 to C10 straight-chain alkyl, C6 to C9 straight-chain alkyl, or C7 to C8 straight-chain alkyl. Preferably, the straight-chain aliphatic molecule does not contain an aromatic structure.

[0099] Preferably, the branched aliphatic polyisocyanate molecule is selected from C2 to C20 branched alkyl, more preferably C3 to C15 branched alkyl, C4 to C12 branched alkyl, C5 to C10 branched alkyl, C6 to C9 branched alkyl, and C7 to C8 branched alkyl.

[0100] Compared to long-chain analogs, the shorter the carbon chain of a polyisocyanate molecule, the higher the reaction rate.

[0101] Cyclic aliphatic polyisocyanate molecules comprise at least one, i.e., one, two, three, four, or more, non-aromatic ring structures, wherein the ring structure itself preferably consists of only carbon atoms. Of course, the carbon atoms of the ring structure can carry suitable substituents. Preferably, at least one ring structure consists of 3, 4, 5, 6, 7, or 8-membered rings independently. Preferably, the cyclic aliphatic molecule comprises 2 to 20 carbon atoms, for example, 3 to 15 carbon atoms, 4 to 12 carbon atoms, 5 to 10 carbon atoms, 6 to 9 carbon atoms, or 7 to 8 carbon atoms.

[0102] In another variation of the method according to the invention, the polyisocyanate is an aromatic polyisocyanate. The term "aromatic polyisocyanate" refers to any polyisocyanate compound in which two or more isocyanate groups are directly bonded to an aromatic carbon atom and which contains, for example, phenyl, tolyl, xylyl, naphthyl or diphenyl units as aromatic components, as well as derivatives of such polyisocyanate compounds.

[0103] Aromatic polyisocyanates react significantly faster than aliphatic polyisocyanates, and are therefore preferred for use in the method according to the present invention.

[0104] Linear, branched, or cyclic aliphatic or aromatic polyisocyanates can exist as monomers or polymers, respectively. A monomeric polyisocyanate is a molecule that is not linked to another molecule, particularly not by one or more crosslinking agents. A polymeric polyisocyanate comprises at least two monomers linked by one or more crosslinking agents. The at least two monomers are not necessarily the same monomers, but can be different monomers. Preferably, the polymeric polyisocyanate contains at least two or more monomers, i.e., at least 2, 3, 4, 5, 10, 20, 30, 40, 50, 100, or more monomers linked together by at least one crosslinking agent.

[0105] Preferably, the linear, branched, or cyclic aliphatic or aromatic polyisocyanates have a limited size / molecular weight, thus allowing them to react with one or more crosslinking agents. Preferably, examples of suitable molecular weights include from about 100 g / mol to 5.10 g / mol. 4 g / mol, preferably 120 g / mol to 2.10 g / mol 4 g / mol, 140 g / mol to 10 4 g / mol, 160 g / mol to 5.10 3 g / mol, 180 g / mol to 2.10 3 g / mol, 200 g / mol to 10 3 g / mol, 220 g / mol to 900 g / mol, 240 g / mol to 800 g / mol, 260 g / mol to 700 g / mol, 280 g / mol to 600 g / mol, 300 g / mol to 500 g / mol, 320 g / mol to 450 g / mol or 340 g / mol to 400 g / mol.

[0106] Any variety of straight-chain, branched, and / or cyclic aliphatic and / or aromatic polyisocyanates may be used. For example, at least one, i.e., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 different straight-chain aliphatic polyisocyanates may be used. For example, at least one, i.e., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 different branched aliphatic polyisocyanates may be used. For example, at least one, i.e., at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 different branched cyclic polyisocyanates may be used.

[0107] Preferably, derivatives of linear, branched, and / or cyclic aliphatic polyisocyanates are used. As used herein, a derivative is understood in the broadest sense as a compound derived from a given compound through a chemical reaction. Examples of derivatives include oligomers and / or adducts of the aforementioned linear or branched aliphatic polyisocyanates. Preferred oligomers are biuret, isocyanurates, urea diketones, and iminooxadiazine diketones, and preferred adducts are trimethylolpropane adducts. These oligomers / adducts are known in the art and are disclosed, for example, in US 4855490 A or US 4144268 A.

[0108] Preferably, the aliphatic polyisocyanate exists only in monomeric and / or dimeric form (as isocyanate) or in oligomeric form.

[0109] Derivatives of linear, branched, or cyclic polyisocyanates and / or mixtures thereof can also be obtained by reacting polyisocyanates with polyols (e.g., glycerol), polyamines, or polythiols (e.g., dimercaptopropanol).

[0110] Isocyanate compounds as defined above explicitly include various isomers, either alone or in combination (if present). For example, methylene bis(cyclohexyl isocyanate) (H12MDI) includes 4,4'-methylene bis(cyclohexyl isocyanate), 2,4'-methylene bis(cyclohexyl isocyanate), and / or 2,2'-methylene bis(cyclohexyl isocyanate).

[0111] Exemplary aliphatic polyisocyanates include those commercially available, such as BAYHYDURN 304 and BAYHYDUR N3Q5, which are aliphatic water-dispersible polyisocyanates based on hexamethylene diisocyanate; DESMODUR N3400, DESMODUR 3600, DESMODUR 3700, and DESMODUR 3900, which are low-viscosity, multifunctional aliphatic polyisocyanates based on hexamethylene diisocyanate; and DESMODUR 3600 and DESMODUR N100, which are aliphatic polyisocyanates based on hexamethylene diisocyanate, each of which is available from Bayer Corporation, Pittsburgh, PA.

[0112] According to another preferred variant of the invention, the linear or branched aliphatic polyisocyanate is selected from the group consisting of: pentamethylene diisocyanate (PDI, such as Stabio D-370N or D-376N from Mitsui Chemicals Inc., Japan), hexamethylene diisocyanate (HDI), ethyl lysine triisocyanate, ethyl lysine diisocyanate and derivatives thereof, preferably, wherein any of said derivatives comprises more than one isocyanate group, and optionally further comprises one or more groups selected from the group consisting of: biuret, isocyanurate, urea dione, iminooxadiazine dione and trimethylolpropane adduct, and / or said cyclic aliphatic polyisocyanate is selected from the group consisting of: isophorone diisocyanate (IPDI), 1,3-bis(methyl isocyanate)cyclohexane (H6XDI, such as Takenate from Mitsui Chemicals Inc., Japan). 600), 1,2-bis(methyl isocyanate)cyclohexane, 1,4-bis(methyl isocyanate)cyclohexane, methylene bis(cyclohexyl isocyanate) (H12MDI) and their derivatives, preferably, wherein any of said derivatives comprises more than one isocyanate group, and where possible, also comprises one or more groups selected from the group consisting of: H6XDI, especially Takenate D-120N of Mitsui Chemicals Co., Ltd. of Japan, biuret, isocyanurate, urea diketone, iminooxadiazine diketone and trimethylolpropane adduct (such as TMP adduct).

[0113] Aliphatic polyisocyanates obtained from renewable raw materials such as PDI (Stabio D-370N or D-376N from Mitsui Chemicals, Ltd., Japan) are particularly preferred. Studies have found that such aliphatic polyisocyanates obtained from renewable raw materials do not affect the quality / performance of the core-shell capsules.

[0114] Other suitable commercially available polyisocyanates include LUPRANAT M20 (BASF), with an average n of 0.7; PA PI 27 (Dow Chemical), with an average n of 0.7; MONDUR MR (Bayer), with an average n of 0.8; MONDUR MR Light (Bayer), with an average n of 0.8; MONDUR 489 (Bayer), with an average n of 1.0; poly(phenylisocyanat)-co-formaldehyd (Aldrich Chemical, Milwaukee, WI), and other isocyanate monomers such as DESMODUR 3200 (Bayer) and TAKENATE D110-N (Mitsui Chemicals Corporation, Rye Brook, NY). Other representative polyisocyanates include those named TAKENATE D-110N (Mitsui), DESMODUR L75 (Bayer), and DESMODUR IL (Bayer).

[0115] In a preferred variant, the polyisocyanate used in the preparation of the polyurea / polyurethane microcapsules according to the invention is used as a separate polyisocyanate component, i.e., no other different polyisocyanate components are added.

[0116] Examples of monomeric polyisocyanates comprising at least two polyisocyanate groups that can be used according to the present invention include: 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, and 1,3-phenylene diisocyanate. 1,4-phenylene diisocyanate, mixtures of 1,3-phenylene diisocyanate and 1,4-phenylene diisocyanate, p-phenylene diisothiocyanate, xylene-1,4-diisothiocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, mixtures of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, xylene-1,4-diisocyanate, xylene-1,3-diisocyanate, and xylene-1,4-diisocyanate and xylene-1,3-diisocyanate Mixtures of cyanates, 2,4-hexahydrotoluene diisocyanate, 2,6-hexahydrotoluene diisocyanate, mixtures of 2,4-hexahydrotoluene diisocyanate and 2,6-hexahydrotoluene diisocyanate, hexahydro-1,3-phenylene diisocyanate, hexahydro-1,4-phenylene diisocyanate, mixtures of hexahydro-1,4-phenylene diisocyanate and hexahydro-1,4-phenylene diisocyanate, 1,3-diisocyanate benzene, 1,3,5-trimethylbenzene-2,4-diisocyanate, 1,3,5-trimethylbenzene-2,4-diisocyanate, etc. Isopropylbenzene-2,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, triphenylmethane-4,4',4"-triisocyanate, toluene-2,4,6-triisocyanate, dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate, or a mixture of the above compounds.

[0117] Polymerizable compounds having at least two polyisocyanate groups are preferably industrially prepared diisocyanates and polyisocyanates, such as TDI: toluene diisocyanate (a mixture of isomers of 2,4- and 2,6-toluene diisocyanate in a ratio of 80:20), HDI: hexamethylene-1,6-diisocyanate, IPDI: isophorone diisocyanate, or DMDI: diphenylmethane-4,4'-diisocyanate.

[0118] Other particularly preferred monomeric polyisocyanate compounds are: diisocyanates, such as 1,4-butane diisocyanate, 1,6-hexane diisocyanate, 1,5-diisocyanate-2,2-dimethylpentane, 2,2,4- and 2,4,4-trimethyl-1,6-diisocyanate hexane, 1,10-decane diisocyanate, 1,3- and 1,4-cyclohexane diisocyanate, 1-polyisocyanate-3,3,5-trimethyl-5-methylcyclohexane diisocyanate (isophorone diisocyanate), 4,4'-diisocyanate dicyclohexylmethane, 2,4- and 2,6-diisocyanate methylcyclohexane, and mixtures thereof. Aromatic polyisocyanates, such as toluene diisocyanate or 4,4'-diisocyanate diphenylmethane, may also be used in principle.

[0119] Other specific examples of diisocyanates include, for example, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), hydrogenated MDI (H12MDI), xylene diisocyanate (XDI), tetramethylxylene diisocyanate (TMXD1), 4,4'-diphenyldimethylmethane diisocyanate, dialkyldiphenylmethane diisocyanate and tetraalkyldiphenylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, isomers of toluene diisocyanate (TDI), and (where applicable) in mixtures, 1-methyl-2,4-diisocyanate cyclohexane, 1,6-diisocyanate-2,2,4-trimethylhexane. 1,6-Diisocyanate-2,4,4-trimethylhexane, 1-isocyanate-methyl-3-isocyanate-1,5,5-trimethylcyclohexane, chlorinated and brominated diisocyanates, phosphorus-containing diisocyanates, 4,4'-diisocyanate-phenylperfluoroethane, tetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate, hexane-1,6-diisocyanate (HDI), dicyclohexylmethane diisocyanate, cyclohexane-1,4-diisocyanate, ethylene diisocyanate, ethyl phthalate diisocyanate, and polyisocyanates having reactive halogen atoms, such as 1-chloromethylphenyl-2,4-diisocyanate-1,2-bromo-3,3-dichloromethyl ether-4,4'-diphenyl diisocyanate.

[0120] Surprisingly, in particular, the use of long-chain aliphatic diisocyanates with 6, 7, 8, 9, 10 or even more carbon atoms can form more stable capsule shells or capsule walls.

[0121] In a particularly preferred embodiment, the internal non-aqueous phase comprises a mixture of two or more different polymerizable polyisocyanates, such as polyisocyanates with different chain lengths, which can form a copolymer.

[0122] The above-mentioned diisocyanates or mixtures thereof can be prepared by modifying them according to known methods, and derivatives of polyisocyanates, such as those containing urea diketone, urethane, isocyanurate, biuret and / or urethane groups, can also be used in proportion in the method of the present invention.

[0123] Particularly preferred are combinations of at least two different, preferably aliphatic, polyisocyanates, or combinations of at least one aliphatic and at least one aromatic polyisocyanate.

[0124] This combination takes advantage of the different reaction rates of polyisocyanates: aromatic polyisocyanates react significantly faster than aliphatic polyisocyanates, and short-chain aliphatic polyisocyanates, i.e., aliphatic polyisocyanates with 1 to 5 carbon atoms, preferably 3 to 5 carbon atoms, react at a higher rate than long-chain analogs.

[0125] In another preferred embodiment of the invention, different aliphatic and / or aromatic polyisocyanates also have different chain lengths. In this context, long-chain polyisocyanates preferably have 6, 7, 8, 9, 10, 11, 12, 13, 14, 20, 25 or more carbon atoms, but more preferably 6 to 12 carbon atoms, and particularly preferably 6 to 8 carbon atoms. Short-chain polyisocyanates refer to polyisocyanates having 1 to 5 carbon atoms, preferably 3 to 5 carbon atoms.

[0126] According to the present invention, a preferred combination is a short-chain aliphatic polyisocyanate (C1, C2, C3, C4, C5) and a long-chain aliphatic polyisocyanate (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more), or a combination of a short-chain aliphatic polyisocyanate (C1, C2, C3, C4, C5) and a long-chain aromatic polyisocyanate (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more). 9. A combination of C10, C11, C12, C13, C14, C15, C20, C25 or more, or a combination of long-chain aliphatic polyisocyanates (C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C20, C25 or more) and short-chain aromatic polyisocyanates.

[0127] In this regard, it is particularly preferred to use a mixture of different aliphatic polyisocyanates having two or more isocyanate groups with a chain length of 1 to 12 carbon atoms, preferably 3 to 8 carbon atoms, and particularly preferably 4 to 7 carbon atoms, to prepare the biodegradable microcapsules according to the invention.

[0128] In this regard, aliphatic polyisocyanates are particularly preferred due to their chemical relationship with bio-based systems. For example, lysine and 1,5-diisocyanopentane both exhibit the same degradation product, 1,5-diaminopentane, and are therefore particularly suitable for the preparation of bio-based and biodegradable microcapsules, taking environmental considerations into account.

[0129] The main implementation scheme includes a mixture of long-chain and short-chain diisocyanates in any proportion. Preferably, the mixing ratio of long-chain diisocyanate to short-chain diisocyanate is in the range of 4:1 to 1:4, and particularly preferably in the range of 2:1 to 1:2.

[0130] Examples of preferred specific mixtures consisting of at least one aliphatic polyisocyanate and at least one aromatic polyisocyanate are: a mixture of hexamethylene diisocyanate biuret and xylene diisocyanate trimethylol adduct, a mixture of hexamethylene diisocyanate biuret and diisocyanate polyisocyanate, or a mixture of hexamethylene diisocyanate biuret and xylene diisocyanate trimethylolpropane adduct.

[0131] More preferably according to the present invention, in the above-described combination of short-chain aliphatic polyisocyanates and long-chain aliphatic polyisocyanates, or in the combination of short-chain aliphatic polyisocyanates and long-chain aromatic polyisocyanates, or in the combination of long-chain aliphatic polyisocyanates and short-chain aromatic polyisocyanates, the polyisocyanates exist as a mixture in monomeric or oligomeric or polymeric form.

[0132] Preferably, for use in the method according to the invention, the following combination is thus achieved:

[0133] - Short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers);

[0134] - Short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and long-chain aliphatic polyisocyanates (monomers, oligomers, or polymers);

[0135] - Short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and short-chain aromatic polyisocyanates (monomers, oligomers, or polymers);

[0136] - Short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and long-chain aromatic polyisocyanates (monomers, oligomers, or polymers);

[0137] - Long-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and short-chain aliphatic polyisocyanates (monomers, oligomers, or polymers);

[0138] - Long-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and long-chain aliphatic polyisocyanates (monomers, oligomers, or polymers);

[0139] - Long-chain aliphatic polyisocyanates (monomers, oligomers, or polymers) and short-chain aromatic polyisocyanates (monomers, oligomers, or polymers);

[0140] - Long-chain aliphatic polyisocyanates (monomers) and long-chain aromatic polyisocyanates (oligomers or polymers);

[0141] Use the definitions of short chains and long chains described above.

[0142] It can be observed that, due to the different reaction rates, dissociation and cross-linking structures of the polyisocyanate components, selecting at least two aliphatic polyisocyanates with different chain lengths and degrees of polymerization, or selecting a mixture of aliphatic polyisocyanates and aromatic polyisocyanates, can significantly improve stability and performance (in the case of fragrance or flavor capsules, releasing the fragrance).

[0143] The above-mentioned polyisocyanate combinations or mixtures of polyisocyanates consisting of two different aliphatic or one aliphatic and one aromatic polyisocyanate can be used to produce particularly stable and better, i.e., more densely branched crosslinks within the capsule shell.

[0144] Therefore, the methods described herein can be used to prepare high-performance (fragrance-releasing) microcapsules made from a mixture of aliphatic and aromatic polyisocyanates or a mixture of two different aliphatic polyisocyanates. Such microcapsules are highly stable and characterized by outstanding fragrance preservation properties, which in turn result in better encapsulation performance (fragrance release), for example, in the field of fragrance or flavor encapsulation.

[0145] Microcapsules produced using two different polyisocyanates again surpassed the stability of microcapsules made from a single polyisocyanate system, as illustrated in the examples below.

[0146] As illustrated in the examples below, microcapsules made from aliphatic-aliphatic polyisocyanate mixtures are just as good as microcapsules made from aliphatic-aromatic polyisocyanate mixtures. Therefore, in principle, combinations of at least two different polymerizable (preferably aliphatic and / or aromatic) polyisocyanates are preferred in this invention.

[0147] The content of the first crosslinking agent in the internal non-aqueous phase is in the range of 0.1% to 5% by weight relative to the total weight of the non-aqueous phase, preferably in the range of 0.15% to 2.5% by weight. Most preferably, the amount of the first crosslinking agent in the internal non-aqueous phase is in the range of 0.5% to 1% by weight relative to the total weight of the non-aqueous phase.

[0148] The first crosslinking agent is added to the internal non-aqueous phase, for example, in solid form or in aqueous solution form.

[0149] The concentration of the first crosslinking agent in the aqueous solution is from 0.01 to 2 mol / L, preferably from 0.1 to 1.5 mol / L, and most preferably from 0.5 to 1.0 mol / L. The pH of the solution is from 7 to 14, preferably 12.

[0150] To improve the cross-linking of at least one polysaccharide and / or at least one protein, at least one other cross-linking agent may optionally be added to the internal non-aqueous phase. The other cross-linking agent is different from the first cross-linking agent.

[0151] At least one other cross-linking agent is selected from the group consisting of: transglutaminase, peroxidase, plant secondary metabolites, and mixtures of two or more of the above cross-linking agents, wherein the plant secondary metabolites are selected from the group consisting of: polyphenols, especially tannins, gallic acid, ferulic acid, hesperidin, cinnamaldehyde, vanillin, and carvacrol.

[0152] Transglutaminase, as an enzyme, catalyzes cross-linking through isopeptide bonds between two amino acids (glutamine and lysine). Phenolic groups in plant secondary metabolites cross-link with peptides via hydrogen bonds. Aldehydes, cinnamaldehyde, and vanillin undergo covalent reactions with the free amino groups of proteins through reactive aldehyde groups.

[0153] Among the other crosslinking agents mentioned above, cinnamaldehyde, tannin, and gallic acid are particularly preferred.

[0154] A particularly advantageous combination of a first crosslinking agent and another crosslinking agent is:

[0155] Polyisocyanate + transglutaminase;

[0156] Polyisocyanate + peroxidase;

[0157] Polyisocyanates + polyphenols;

[0158] Polyisocyanates + tannins;

[0159] Polyisocyanate + gallic acid;

[0160] Polyisocyanate + ferulic acid;

[0161] Polyisocyanates + hesperidin;

[0162] Polyisocyanate + cinnamaldehyde;

[0163] Polyisocyanates + vanillin;

[0164] Polyisocyanates + carvacrol; or

[0165] Polyisocyanate + a mixture of two or more of the above-mentioned crosslinking agents.

[0166] The content of another crosslinking agent in the internal non-aqueous phase is in the range of 0.05 to 5% by weight, preferably in the range of 0.1 to 2% by weight, relative to the total weight of the non-aqueous phase. Most preferably, the amount of the first crosslinking agent in the internal non-aqueous phase is in the range of 0.15 to 1% by weight, relative to the total weight of the non-aqueous phase.

[0167] Another type of crosslinking agent is added to the internal non-aqueous phase, either as a solid or in aqueous solution.

[0168] The other crosslinking agent is present in an 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 of 7 to 14, preferably 12.

[0169] By combining at least one first crosslinking agent and at least one other crosslinking agent that are different from each other, the stability of the microcapsules is significantly improved, thereby reducing the proportion of aromatic oil leakage.

[0170] Due to the low content of the polyisocyanate component, protein and / or polysaccharide microcapsules containing at least one lipophilic active substance to be encapsulated can be prepared according to the present invention, wherein the absolute content of polyisocyanate in the microcapsule is only 1 / 50 of the entire capsule. Therefore, the method according to the present invention can prepare protein and / or polysaccharide microcapsules with a polyisocyanate content of only 0.6% by weight relative to the total weight of the capsule. Preferably, the polyisocyanate content is about 1.8% by weight of the capsule. Despite the low polyisocyanate content, the microcapsules according to the present invention still exhibit high stability.

[0171] In step (i) of the method according to the invention, at least one crosslinking agent is first dissolved, optionally substantially, in an inert non-aqueous solvent or a mixture of inert non-aqueous solvents. The term "substantially dissolved" should be understood to mean that at least 90% by weight, preferably at least 98% by weight, and even more preferably 99.9% by weight, of the aforementioned components are dissolved in the solvent or solvent mixture for use in this method. Preferably, at least one polyisocyanate and at least one active substance to be encapsulated are completely dissolved in the solvent or solvent mixture. If the solvent cannot guarantee sufficient dissolution of the isocyanate, this disadvantage can be overcome by using a suitable solubility promoter.

[0172] The preferred solvent for use in the internal non-aqueous phase is immiscible with water, does not react with isocyanate components or active substances, and has little or no odor in the amount used.

[0173] The term "solvent" as used in this invention includes all types of oil bodies or oil components, particularly vegetable oils (e.g., rapeseed oil, sunflower oil, soybean oil, olive oil, etc.), modified vegetable oils (e.g., alkoxylated sunflower oil or soybean oil), synthetic glycerol (tri) esters (e.g., engineered mixtures of monoglycerides, diglycerides, and triglycerides of C6 to C22 fatty acids), and fatty acid alkyl esters (e.g., methyl or ethyl esters of vegetable oils). ME 18RD-F, ME18SD-F, ME 12C-F, ME1270), fatty acid alkyl esters based on C6 to C22 fatty acids), mineral oils, and mixtures thereof. Suitable and preferred examples of lipophilic solvents include: Guerbert alcohols based on fatty alcohols having 6 to 18, preferably 8 to 10 carbon atoms; straight-chain C6 to C22 fatty acid esters of straight-chain or branched C6 to C22 fatty alcohols; or branched C6 to C13 carboxylic acid esters of straight-chain 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 erucate, stearyl myristate, stearyl palmitate. Stearyl stearate, isostearyl stearate, oleic acid stearate, stearyl stearate, erucic acid stearate, myristate isostearyl stearate, palmitic acid isostearyl stearate, isostearyl stearate, isostearyl stearate, oleic acid isostearyl stearate, betaine isostearyl stearate, myristate oleate, palmitic acid oleate, stearic acid oleate, isostearyl stearate Oleic acid ester, oleic acid ester, behenic acid ester, erucic acid ester, myristate behenic acid ester, palmitic acid behenic acid ester, stearic acid behenic acid ester, isostearic acid behenic acid ester, oleic acid behenic acid ester, behenic acid behenic acid ester, myristic acid behenic acid ester, palmitic acid behenic acid ester, stearic acid behenic acid ester, isostearic acid behenic acid ester, oleic acid behenic acid ester and behenic acid behenic acid ester.

[0174] Also suitable are esters of straight-chain C6 to C22 fatty acids with branched-chain alcohols, particularly 2-ethylhexanol; esters of C18 to C38 alkyl hydroxycarboxylic acids with C6 to C22 straight-chain or branched fatty acids, particularly dioctyl esters; esters of straight-chain or branched fatty acids with polyols (e.g., propylene glycol, glycol, or trimerol) and / or guerbert alcohols; triglycerides based on C6 to C10 fatty acids; liquid monoglycerides / diglycerides / triglycerides of C6 to C18 fatty acids; esters of C6 to C22 fatty alcohols and / or guerbert alcohols with aromatic carboxylic acids, particularly benzoic acid; esters of C2 to C12 dicarboxylic acids with straight-chain or branched alcohols having 1 to 22 carbon atoms or polyols having 2 to 10 carbon atoms and 2 to 6 hydroxyl groups; vegetable oils; branched primary alcohols; substituted cyclohexanes; and straight-chain or branched C6 to C22 fatty alcohol carbonates, such as dioctyl carbonate. CC); Gerbert carbonates based on fatty alcohols having 6 to 18, preferably 8 to 10 carbon atoms; benzoates having straight-chain or branched C6 to C22 alcohols; straight-chain or branched, symmetrical or asymmetrical dialkyl ethers, such as dioctyl ethers, each alkyl group having 6 to 22 carbon atoms; ring-opening products of epoxidized fatty acid esters and polyols; silicone oils (cyclic polymethylsiloxanes, polymethylsiloxane-grade polysiloxanes). (etc.), aliphatic or cycloalkyl hydrocarbons, such as squalane, squalene or dialkylcyclohexane and / or mineral oils.

[0175] In particular, preferred solvents are esters of straight-chain C6 to C22 fatty acids with branched-chain alcohols, esters of C18 to C38 alkyl hydroxycarboxylic acids with C6 to C22 straight-chain or branched-chain fatty alcohols, straight-chain or branched C6 to C22 fatty alcohols, especially dioctyl malate, esters of straight-chain or branched fatty acids with polyols such as propylene glycol, dimerized glycol or trimerized glycol, and / or guerbert alcohol, triglycerides based on C6 to C10 fatty acids, and esters based on C6 to C18 fatty acids. Liquid mixtures of mono- and di- and tri-glycerides; esters of C6- to C22 fatty alcohols and / or Guerbert alcohols with aromatic carboxylic acids, particularly benzoic acid; esters of C2- to C12 dicarboxylic acids with straight-chain or branched alcohols having 1 to 22 carbon atoms or polyols having 2 to 10 carbon atoms and 2 to 6 hydroxyl groups; vegetable oils; branched primary alcohols; substituted cyclohexanes; straight-chain or branched C6- to C22 fatty alcohol carbonates, such as bis(octyl) carbonate. TM CC), based on a fatty alcohol having 6 to 18, preferably 8 to 10 carbon atoms, esters of benzoic acid with straight-chain or branched C6 to C22 alcohols, straight-chain or branched dialkyl ethers having 6 to 22 carbon atoms per alkyl group, such as bis(octyl) ether (Cetiol TM OE), ring-opening products of epoxidized fatty acid esters and polyols, silicone oils (cyclic polymethylsiloxane and polymethylsiloxane-type silicone, etc.) and / or aliphatic hydrocarbons or cycloalkanes, such as squalane, squalene or dialkylcyclohexane.

[0176] Furthermore, within the scope of this invention, liquid straight-chain and / or branched and / or saturated or unsaturated hydrocarbons, or any desired mixture thereof, can be used as solvents. For example, the solvent may be an alkane having 4 to 22 carbon atoms, preferably 6 to 18 carbon atoms, or any mixture thereof.

[0177] Particularly advantageously suitable inert solvents for use as internal non-aqueous phases are: alkyl aromatics such as diisopropylnaphthalene or substituted biphenyls, chlorinated biphenyls, paraffin, chlorinated paraffin, natural vegetable oils (such as cottonseed oil, peanut oil and palm oil), tricresyl phosphate, silicone oil, dialkyl phthalate, dialkyl adipate, partially hydrogenated terphenyl, alkylated biphenyl, alkylated naphthalene, diaryl ethers, arylalkyl ethers and highly alkylated benzene, benzyl benzoate, isopropyl myristate, and any mixture of these hydrophobic solvents and mixtures of one or more of these hydrophobic solvents with kerosene, paraffin and / or isoparaffins.

[0178] Preferably, vegetable oil, triglycerides, benzyl benzoate, or isopropyl myristate is used as the solvent for providing the internal non-aqueous phase. Most preferably, the vegetable oil is selected from the group consisting of: palm oil, soybean oil, rapeseed oil, sunflower oil, palm kernel oil, cottonseed oil, peanut oil, corn germ oil, coconut oil, olive oil, sesame oil, flaxseed oil, safflower oil, modified vegetable oils, and mixtures thereof.

[0179] The solvents described above are used either alone or as a mixture of two or more solvents in the method according to the invention.

[0180] In alternative and preferred variations of the method according to the invention, at least one polyisocyanate is directly dissolved in a solution of the at least one active substance, which is preferably one or more fragrances or flavorings / fragrances or flavorings or spice oils, so that the aforementioned solvent is substantially absent in the core of the microcapsule according to the invention. In this respect, avoiding the use of solvents in the microcapsule core is beneficial for reducing manufacturing costs and taking environmental factors into consideration.

[0181] Specifically, the fragrance or flavoring agent is dissolved in solvents commonly used in the fragrance or flavoring industry. Preferably, the solvent is not an alcohol, as alcohols react with isocyanates. Examples of suitable solvents are diethyl phthalate, isopropyl myristate, etc. (Rosin resin, available from Eastman), benzyl benzoate, ethyl citrate, limonene, or other terpenes or isoalkanes. Preferably, the solvent is highly hydrophobic. Preferably, the fragrance or flavoring solution contains less than 30% solvent. More preferably, the fragrance or flavoring solution contains less than 20%, and even more preferably less than 10%, of solvent, wherein all these percentages are defined by weight relative to the total weight of the fragrance or flavoring solution. Most preferably, the fragrance or flavoring is substantially solvent-free.

[0182] If the at least one hydrophobic active substance has already been mixed with a solvent or solvent mixture, then the use of an inert solvent or solvent mixture is not necessary. In this case, at least one first crosslinking agent can be directly mixed with the hydrophobic active agent to obtain an internal non-aqueous phase.

[0183] In the method according to the invention, the active substance or core material to be encapsulated, in principle, can be any material suitable for encapsulation in the microcapsules. The active substance to be encapsulated is preferably hydrophobic, i.e., a liquid or solid, or suspension, that is insoluble in or immiscible with water. These primarily involve nonpolar substances. Such hydrophobic substances are almost always lipophilic, i.e., they dissolve well in fats and oils.

[0184] In the context of this specification, nuclear material is a hydrophobic active substance, that is, a substance that has a specific effect or causes a specific reaction, such as pharmaceuticals, plant protectants, cosmetic active substances, and food active substances.

[0185] At least one active substance to be encapsulated in the method according to the invention is a hydrophobic or lipophilic active substance. This ensures that, during the preparation of microcapsules according to the invention, the active substance to be encapsulated is in an internal non-aqueous phase and does not mix with the external aqueous phase, which would otherwise prevent the formation of an emulsion or the deposition of capsule wall material on the droplet surface. This results in the lipophilic active substance being completely encapsulated within the microcapsule as a core material during subsequent emulsification and crosslinking of the capsule wall components. The resulting internal non-aqueous phase is characterized by organic hydrophobicity and oiliness.

[0186] In a particularly preferred variant of the invention, at least one lipophilic or hydrophobic active substance, particularly a lipophilic or hydrophobic fragrance or flavoring agent, or a lipophilic or hydrophobic fragrance oil or flavoring (a mixture of fragrances or flavoring agents), a cooling agent, a TRPV1 or TRPV3 modifier, a substance that causes an irritating taste or heat or hot sensation on the skin or mucous membranes, or a substance that causes a tingling or stinging sensation in the mouth or throat, or an active substance having an irritating, spicy, or astringent effect, a substance in the class of pesticides, biocides, insecticides, and repellents, a food additive, a cosmetic active substance, a pharmaceutical active substance, a dye, a dye precursor, an agrochemical, a dye, a fluorescent dye, an optical brightener, a solvent, a wax, a silicone oil, a lubricant, a paper printing coating substance, or a mixture of two or more of the above active substances.

[0187] In preferred variants of the invention, hydrophobic fragrances or fragrance mixtures consisting of two or more fragrances (fragrance oils), or hydrophobic flavorings or flavoring mixtures consisting of two or more flavorings (fragrances), or even bio-derived substances, are considered as hydrophobic or lipophilic active substances.

[0188] In a preferred embodiment of the first and / or second aspect of the invention, the microcapsule comprises a core material in the form of a hydrophobic single aromatic agent or single fragrance agent, wherein the core material comprises at least one single aromatic agent or single fragrance agent or mixture thereof, selected from one or more of the following: extracts of natural raw materials and their fractions or components isolated therefrom; single aromatic agents in the hydrocarbon category; fatty alcohols; fatty aldehydes and acetals; fatty ketones and oxime compounds; aliphatic sulfur-containing compounds; aliphatic nitriles; fatty carboxylic acid esters; formate, acetate, propionate, isobutyrate, butyrate, isovalerate, valerate, hexanoate, crotonate, terpene acid ester, and 3-methyl-2- Butenoic acid esters; acyclic terpene aldehydes and ketones and their dimethyl and diethyl acetals; formate, acetate, propionate, isobutyrate, butyrate, isovalerate, valerate, hexanoate, crotonate, terpeneate and 3-methyl-2-butenoic acid esters of acyclic terpene alcohols; cyclic terpene aldehydes and ketones; cyclic alcohols; cyclic ethers and alicyclic ethers; cyclic ketones and macrocyclic ketones; alicyclic aldehydes; alicyclic ketones; cyclic alcohol esters; esters of alicyclic alcohols; esters of alicyclic carboxylic acids; aromatic hydrocarbons; aryl alcohols; esters of aryl alcohols and fatty carboxylic acids; aryl ethers; aromatic aldehydes and aryl aldehydes; aromatic and alicyclic ketones; aromatic and alicyclic carboxylic acids and their esters; nitrogen-containing aromatic compounds; phenyl ethers and phenyl esters; heterocyclic compounds; lactones; and mixtures of the above-mentioned active substances.

[0189] For example, suitable fragrances and flavorings for manufacturing capsules according to the present invention are preferably described in Steffen Arctander, “Fragrances”, “Perfume and Flavor Chemicals”, published in Montclair, NJ, 1969; and in H. Surburg and J. Panten, “Common Fragrance and Flavor Materials”, Wiley-VCH, Weinheim, 2006, 5th edition.

[0190] Preferably, the microcapsules according to the invention comprise a core material in the form of a hydrophobic single fragrance or single flavoring agent, wherein the core material comprises at least one single fragrance or single flavoring agent selected from one or more of the following groups:

[0191] - Hydrocarbons, such as 3-carene; α-pinene; β-pinene; α-terpinene; γ-terpinene; p-cymene; bisabolene; camphene; caryophyllene; cedrene; farnesene; limonene; longleafene; myrcene; ocimene; Valencia citrusene; (E,Z)-1,3,5-undecanetriene;

[0192] - Fatty alcohols, such as hexanol; octanol; 3-octanol; 2,6-dimethylheptanol; 2-methylheptanol; 2-methyloctanol; (E)-2-hexenol; (E) and (Z)-3-hexenol; 1-octen-3-ol; mixtures of 3,4,5,6,6-pentamethyl-3,4-hepten-2-ol and 3,5,6,6-tetramethyl-4-methylenehepten-2-ol; (E,Z)-2,6-nonadienol; 3,7-dimethyl-7-methoxyoctane-2-ol; 9-decenol; 10-undecenol; 4-methyl-3-decen-5-ol;

[0193] -Aliphatic aldehydes and their acetals, such as hexanal; heptanal; octanal; nonanal; decanal; undecanoal; 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 diacetal; 1,1-dimethoxy-2,2,5-trimethyl-4-hexene; citronelloloxyacetaldehyde;

[0194] -Aliphatic ketones and their oxime compounds, 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;

[0195] - Aliphatic sulfur-containing compounds, such as 3-methylthiohexanol; 3-methylthiohexyl acetate; 3-mercaptohexanol; 3-mercaptohexyl acetate; 3-mercaptohexylbutyrate; 3-acetylthiohexyl acetate; 1-menthol-8-thiol;

[0196] - 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-octadienoic acid nitrile;

[0197] -Aliphatic carboxylic acids and their esters, such as (E)- and (Z)-3-hexenyl carboxylates; ethyl acetoacetate; isoamyl acetate; hexyl acetate; trimethylhexyl 3,5,5-acetate; 3-methyl-2-butenyl acetate; (E)-2-hexenyl acetate; (E)- and (Z)-3-hexenyl acetate; octyl acetate; octyl 3-acetate; 1-octen-3-acetate; ethyl butyrate; butyl butyrate; isoamyl butyrate Esters; Hexyl butyrate; (E) and (Z)-3-hexenyl isobutyrate; Hexyl crotonate; Ethyl isovalerate; Ethyl 2-methylvalerate; Ethyl hexanoate; Allyl hexanoate; Ethyl heptaate; Allyl heptaate; Ethyl octanoate; (E,Z)-2,4-decadienoate; Methyl 2-octanoate; Methyl 2-nonanoate; Allyl 2-isopentyloxyacetate; Methyl 3,7-dimethyl-2,6-octadienoate;

[0198] -Acyclic terpenoids, such as citronellol; geraniol; nerol; linalool; lavenderol; nerolidol; farnesol; tetrahydrolinalool; tetrahydrogeraniol; 2,6-dimethyl-7-octen-2-ol; 2,6-dimethyloctane-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-octtrien-3-ol; 2,6-dimethyl-2,5,7-octtrien-1-ol; and their formates, acetates, propions, isobutyrates, butyrates, isovalerates, valerates, hexanoates, crotonates, terpenes, 3-methyl-2-butenoates.

[0199] -Acyclic terpenoid aldehydes and ketones, such as geranialdehyde; neraldehyde; citronellol; 7-hydroxy-3,7-dimethyloctanal; 7-methoxy-3,7-dimethyloctanal; 2,6,10-trimethyl-9-undecenal; geraniol; and dimethyl and diethyl acetals of geranialdehyde, neraldehyde, and 7-hydroxy-3,7-dimethyloctanal;

[0200] - Cyclic terpenoids, such as menthol; isomenthol; α-terpineol; terpinenol-4; menthane-8-ol; menthane-1-ol; menthane-7-ol; borneol; isoborneol; linalool oxide; noberol; cedrol; ambroxol; vetiverol; guaiacol; and their formates, acetates, propionates, isobutyrate, butyrate, isovalerate, valerate, hexanoate, crotonate, terpineate, 3-methyl-2-butenoate;

[0201] - Cyclic terpenoid aldehydes and ketones, such as menthone; isomenthone; 8-mercaptomenthane-3-one; carvone; camphor; fennelone; α-ionone; β-ionone; α-n-methylionone; β-n-methylionone; α-isomethylionone; β-isomethylionone; α-iridoone; β-iridoone; α-damasone; β-damasone; γ-damasone; d-damasone; 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-methylene-naphthyl-8-(5H)-one; nocarone; dihydronorbutanone; α-sweet orange aldehyde; β-sweet orange aldehyde; acetylated cedar oil (methyl cedarwood ketone);

[0202] Cyclohydric alcohols, such as 4-tert-butylcyclohexanol; 3,3,5-trimethylcyclohexanol; 3-isocampylcyclohexanol; 2,6,9-trimethyl-(Z2,Z5,E9)-cyclododecanetrien-1-ol; 2-isobutyl-4-methyltetrahydro-2H-pyran-4-ol; alicyclic alcohols, such as 3,3,3-trimethylcyclohexylmethanol; 2-methyl-4-(2,2,3-trimethyl-3-cyclopentan-1-yl)butanol; 2-methyl-4-(2,2,3-trimethyl-3-cyclopentan-1-yl)-2-buten-1-ol; 2-ethyl-4- (2,2,3-Trimethyl-3-cyclopentan-1-yl)-2-buten-1-ol; 3-Methyl-5-(2,2,3-Trimethyl-3-cyclopentan-1-yl)-pentan-2-ol; 3-Methyl-5-(2,2,3-Trimethyl-3-cyclopentan-1-yl)-4-penten-2-ol; 3,3-Dimethyl-5-(2,2,3-Trimethyl-3-cyclopentan-1-yl)-4-penten-2-ol; 1-(2,2,6-Trimethylcyclohexyl)pentan-3-ol; 1-(2,2,6-Trimethylcyclohexyl)hexan-3-ol;

[0203] - Cyclic ethers and alicyclic ethers, such as eucalyptol; cedaryl methyl ether; cyclododecyl methyl ether; (ethoxymethoxy)cyclododecane; α-epoxy-cylinderane; 3a,6,6,9a-tetramethyldodecano[2,1-b]furan; 3a-ethyl-6,6,9a-trimethyldodecano[2,1-b]furan; 1,5,9-trimethyl-13-oxobicyclo[10.1.0]tridecyl-4,8-diene; rose oxide; 2-(2,4-dimethyl-3-cyclohexen-1-yl)-5-methyl-5-(1-methylpropyl)-1,3-dioxane;

[0204] Cyclohexanones, such as 4-tert-butylcyclohexanone; 2,2,5-trimethyl-5-pentylcyclopentanone; 2-heptylcyclopentanone; 2-pentylcyclopentanone; 2-hydroxy-3-methyl-2-cyclopenten-1-one; 3-methylcis-2-penten-1-yl-2-cyclopenten-1-one; 3-methyl-2-pentyl-2-cyclopenten-1-one; 3-methyl-4-cyclopentadecenone; 3-methyl-5-cyclopentadecenone; 3-methylcyclopentadecenone; 4-(1-ethoxyvinyl)-3,3,5,5-tetramethylcyclohexanone; 4-tert-pentylcyclohexanone; 5-cyclohexadecene-1-one; 6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)indanone; 9-cycloheptadecene-1-one; cyclopentadecenone; cyclohexadecene;

[0205] - Alicyclic aldehydes, such as 2,4-dimethyl-3-cyclohexenaldehyde; 2-methyl-4-(2,2,6-trimethyl-cyclohexen-1-yl)-2-butenaldehyde; 4-(4-hydroxy-4-methylpentyl)-3-cyclohexenaldehyde; 4-(4-methyl-3-penten-1-yl)-3-cyclohexenaldehyde;

[0206] - Alicyclic ketones, such as 1-(3,3-dimethylcyclohexyl)-4-penten-1-one; 1-(5,5-dimethyl-2-cyclohexen-1-yl)-4-penten-1-one; 2,3,8,8-tetramethyl-1,2,3,4,5,6,7,8-octahydro-2-naphthylmethyl ketone; methyl-2,6,10-trimethyl-2,5,9-cyclododecanetrienyl ketone; tert-butyl(2,4-dimethyl-3-cyclohexen-1-yl) ketone;

[0207] Esters of cycloalcohols, 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-acetate; decahydro-2,5,5,8a-tetramethyl-2-naphthyl acetate; 4,7-bridged methylene-3a,4,5,6,7,7a-hexahydro-5- or -6-indanyl acetate; 4,7-bridged methylene-3a,4,5,6,7,7a-hexahydro-5- or -6-indanylpropionate; 4,7-bridged methylene-3a,4,5,6,7,7a-hexahydro-5- or -6-indanylisobutyrate; 4,7-bridged methylene octahydro-5- and -6-indanyl acetate;

[0208] Esters of alicyclic carboxylic acids, such as allyl-3-cyclohexyl propionate; allylcyclohexyloxyacetic acid; methyl dihydrojasmonic acid; methyl jasmonic acid; methyl 2-hexyl-3-oxocyclopentanecarboxylate; ethyl 2-ethyl-6,6-dimethyl-2-cyclohexenecarboxylate; tetramethyl 2,3,6,6-ethyl-2-cyclohexenecarboxylate; ethyl 2-methyl-1,3-dioxolane-2-ethyl acetate;

[0209] -Aromatic hydrocarbons, such as styrene and diphenylmethane;

[0210] - Fatty alcohols, such as benzyl alcohol; 1-phenylethanol; 2-phenylethanol; 3-phenylpropanol; 2-phenylpropanol; 2-phenoxyethanol; 2,2-dimethyl-3-phenylpropanol; 2,2-dimethyl-3-(3-methylphenyl)propanol; 1,1-dimethyl-2-phenylethanol; 1,1-dimethyl-3-phenylpropanol; 1-ethyl-1-methyl-3-phenylpropanol; 2-methyl-5-phenylpentanol; 3-methyl-5-phenylpentanol; 3-phenyl-2-propen-1-ol; 4-methoxybenzyl alcohol; 1-(4-isopropylphenyl)ethanol;

[0211] - Esters of aliphatic alcohols and fatty carboxylic acids, such as benzyl acetate; benzyl propionate; benzyl isobutyrate; benzyl isovalerate; ethyl 2-phenylacetate; 2-phenylethyl propionate; 2-phenylisobutyrate; 2-isovalerate; ethyl 1-phenylacetate; benzyl α-trichloromethylacetate; ethyl α,α-dimethylphenylacetate; α,α-dimethylphenylethylbutyrate; cinnamyl acetate; ethyl 2-phenoxyisobutyrate; 4-methoxybenzyl acetate;

[0212] -Aromatic ethers, such as 2-phenylethyl methyl ether; 2-phenylethyl isopentyl ether; 2-phenylethyl-1-ethoxyethyl ether; phenylacetaldehyde dimethyl acetal; phenylacetaldehyde diethyl acetal; hydrogenated atroaldehyde dimethyl acetal; phenylacetaldehyde glycerol acetal; 2,4,6-trimethyl-4-phenyl-1,3-dioxane; 4,4a,5,9b-tetrahydroindo[1,2-d]m-dioxin; 4,4a,5,9b-tetrahydro-2,4-dimethylindo[1,2-d]m-dioxin;

[0213] - Aromatic aldehydes and aliphatic aldehydes, such as benzaldehyde; phenylacetaldehyde; 3-phenylpropanal; hydrogenated atroaldehyde; 4-methylbenzaldehyde; 4-methylphenylacetaldehyde; 3-(4-ethylphenyl)-2,2-dimethylpropanal; 2-methyl-3-(4-isopropylphenyl)propanal; 2-methyl-3-(4-tert-butylphenyl)propanal; 3-(4-tert-butylphenyl)propanal; cinnamaldehyde; α-butylcinnamaldehyde; α-pentylcinnamaldehyde; 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;

[0214] -Aromatic and aryl aliphatic ketones, such as acetophenone; 4-methylacetophenone; 4-methoxyacetophenone; 4-tert-butyl-2,6-dimethylacetophenone; 4-phenyl-2-butanone; 4-(4-hydroxyphenyl)-2-butanone; 1-(2-naphthyl)acetone; benzophenone; 1,1,2,3,3,6-hexamethyl-5-indenemethyl ketone; 6-tert-butyl-1,1-dimethyl-4-indenemethyl ketone; 1-[2,3-dihydro-1,1,2,6-tetramethyl-3-(1-methylethyl)-1H-5-indene]acetone; 5',6',7',8'-tetrahydro-3',5',5',6',8',8'-hexamethyl-2-naphthyl acetone;

[0215] -Aromatic and aryl aliphatic carboxylic acids and their esters, such as benzoic acid; phenylacetic acid; methyl benzoate; ethyl benzoate; hexyl benzoate; benzyl benzoate; methyl phenylacetate; ethyl phenylacetate; geraniol phenylacetate; phenylethyl phenylacetate; methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenethyl cinnamate; 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;

[0216] -Nitrogen-containing aromatic compounds, such as 2,4,6-trinitro-1,3-dimethyl-5-tert-butylbenzene; 3,5-dinitro-2,6-dimethyl-4-tert-butylacetophenone; cinnamic acid nitrile; 5-phenyl-3-methyl-2-valeric acid nitrile; 5-phenyl-3-methylvaleric acid nitrile; methyl anthranilate; methyl N-methyl anthranilate; Schiff bases of methyl anthranilate with 7-hydroxy-3,7-dimethyloctanal, 2-methyl-3-(4-tert-butyl-phenyl)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;

[0217] - Phenols, phenyl ethers and phenyl esters, such as estragol; anethole; eugenol; eugenol 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; eugenol acetate; 2-methoxy-4-methylphenol; 2-ethoxy-5-(1-propenyl)phenol; p-tolylphenylacetic acid ester; from the group of heterocyclic compounds, such as 2,5-dimethyl-4-hydroxy-2H-furan-3-one; 2-ethyl-4-hydroxy-5-methyl-2H-furan-3-one; 3-hydroxy-2-methyl-4H-pyran-4-one; 2-ethyl-3-hydroxy-4H-pyran-4-one;

[0218] - Lactones, such as 1,4-octyl lactone; 3-methyl-1,4-octyl lactone; 1,4-nonyl lactone; 1,4-decyl lactone; 8-decen-1,4-lactone; 1,4-undecane lactone; 1,4-dodecane lactone; 1,5-decane lactone; 1,5-dodecane lactone; 1,15-pentadecanalactone; cis- and trans-11-pentadecanalactone; cis- and trans-12-pentadecanalactone; 1,16-hexadecane lactone; 9-hexadecane lactone; Alkene-1,16-lactone; 10-oxa-1,16-hexadecanolide; 11-oxa-1,16-hexadecanolide; 12-oxa-1,16-hexadecanolide; ethylene-1,12-dodecanoic acid ester; ethylene-1,13-tridecanoic acid ester; coumarin; 2,3-dihydrocoumarin; octahydrocoumarin; and stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers or epimers of the above substances.

[0219] Among the single fragrances or single flavorings that can be encapsulated in the sense of the present invention, fragrances or flavorings having aldehyde, carboxylic acid, or ester functional groups are particularly preferred.

[0220] Aldehydes, which also include the corresponding acetals, esters and lactones, can be classified into the following categories: (i) aliphatic aldehydes and their acetals.

[0221] (ii) Alicyclic aldehydes;

[0222] (iii) Aromatic aldehydes or aryl aldehydes;

[0223] (iv) Aliphatic, aromatic, or arylaliphatic esters; and

[0224] (v) lactones;

[0225] and its mixtures.

[0226] The above-mentioned fragrances or flavorings having aldehyde, carboxylic acid, or ester functional groups, and mixtures thereof, are selected from one or more of the following groups:

[0227] -Aliphatic aldehydes and their acetals, such as hexanal; heptanal; octanal; nonanal; decanal; undecanoal; dodecanal; tridecanal; 2-methyloctanal; 2-methylnonanal; (f)-2-hexenal; (Z)-4-heptenal; 2,6-dimethyl-5-heptenal; 10-undecenal; (f)-4-decenal; 2-dodecenal; 2,6,10-trimethyl-5,9-undecadienal; heptanal diacetal; 1,1-dimethoxy-2,2,5-trimethyl-4-hexene; citronelloloxyacetaldehyde;

[0228] - Alicyclic aldehydes, such as 2,4-dimethyl-3-cyclohexenaldehyde; 2-methyl-4-(2,2,6-trimethyl-cyclohexen-1-yl)-2-butenaldehyde; 4-(4-hydroxy-4-methylpentyl)-3-cyclohexenaldehyde; 4-(4-methyl-3-penten-1-yl)-3-cyclohexenaldehyde;

[0229] -Aromatic aldehydes and aryl aldehydes, such as benzaldehyde; phenylacetaldehyde; 3-phenylpropanal; hydrogenated atroaldehyde; 4-methylbenzaldehyde; 4-methylphenylacetaldehyde; 3-(4-ethylphenyl)-2,2-dimethylpropanal; 2-methyl-3-(4-isopropylphenyl)-propanal; 2-methyl-3-(4-tert-butylphenyl)propanal; 3-(4-tert-butylphenyl)propanal; cinnamaldehyde; α-butylcinnamaldehyde; α-pentylcinnamaldehyde; 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;

[0230] -Aliphatic carboxylic acid esters, such as (E)- and (Z)-3-hexenyl carboxylates; ethyl acetoacetate; isoamyl acetate; hexyl acetate; 3,5,5-trimethylhexyl acetate; 3-methyl-2-butenyl acetate; (f)-2-hexenyl acetate; (E) and (Z)-3-hexenyl acetate; octyl acetate; 3-octyl acetate; 1-octen-3-acetic acid; ethyl butyrate; butyl butyrate; isoamyl butyrate Esters; Hexyl butyrate; (E) and (Z)-3-isobutyrate hexenyl ester; hexyl crotonate; ethyl isovalerate; ethyl 2-methylvalerate; ethyl hexanoate; allyl hexanoate; ethyl heptaate; allyl heptaate; ethyl octanoate; (E,Z)-2,4-decadienoate; methyl 2-octanoate; methyl 2-nonanoate; allyl 2-isopentyloxyacetate; methyl 3,7-dimethyl-2,6-octadienoate;

[0231] Esters of cycloalcohols, such as 2-tert-butylcyclohexyl acetate; 4-tert-butylcyclohexyl acetate; 2-ieri-pentylcyclohexyl acetate; 4-tert-pentylcyclohexyl acetate; decahydro-2-naphthyl acetate; 3-pentyltetrahydro-2- / - / -pyran-4-yl acetate; decahydro-2,5,5,8a-tetramethyl-2-naphthyl acetate; 4,7-bridged methylene-3a,4,5,6,7,7a-hexahydro-5- or -6-indole isobutyrate; 4,7-bridged methylene-3a,4,5,6,7,7a-hexahydro-5- or -6-indole propionate; 4,7-bridged methylene-3a,4,5,6,7,7a-hexahydro-5- or -6-indole isobutyrate; 4,7-bridged methylene octahydro-5- and -6-indole acetate;

[0232] - Esters of aryl alcohols and fatty carboxylic acids, such as benzyl acetate; benzyl propionate; benzyl isobutyrate; benzyl isovalerate; phenethyl acetate; phenethyl propionate; phenethyl isovalerate; phenethyl isovalerate; phenethyl 1-acetate; α-trichloromethylbenzyl acetate; α,α-dimethylphenylethyl ethyl acetate; α,α-dimethylphenylethyl butyrate; cinnamyl acetate; 2-phenoxyethyl isobutyrate; 4-methoxybenzyl acetate;

[0233] Esters of alicyclic carboxylic acids, such as allyl-3-cyclohexylpropionate; allylcyclohexyloxyacetate; methyl dihydrojasmonic acid; methyl jasmonic acid; 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-ethyl acetate;

[0234] -Aromatic and aryl aliphatic carboxylic acid esters, such as methyl benzoate; ethyl benzoate; hexyl benzoate; benzyl benzoate; methyl phenylacetate; ethyl phenylacetate; geraniol phenylacetate; phenylethyl phenylacetate; methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenylethyl cinnamate; cinnamyl cinnamate; allyl phenoxyacetate; methyl salicylate; isoamyl salicylate; hexyl salicylate; cyclohexyl salicylate; cis-3-hexenyl salicylate; benzyl salicylate; phenylethyl salicylate; methyl 2,4-dihydroxy-3,6-dimethylbenzoate; ethyl 3-phenylglycidate; ethyl 3-methyl-3-phenylglycidate.

[0235] The following lists aldehydes, acetals, esters, and lactones and their commercial names, which are particularly preferred as representatives of groups (i) to (v) for the purposes of the method according to the invention:

[0236] Aldehydes: 2-Methylpentanal; Aldehyde C12 MNAHM; Aldehyde C4; Aldehyde C5; Aldehyde C6; Aldehyde C7; Aldehyde C8; Aldehyde C9; Aldehyde C10; Aldehyde C11 ISO; Aldehyde C11 MOA (pure); Undecylaldehyde C11; Undecylenal C11 (Aldehyde C11 UNDEYLENIC); Aldehyde C12; Aldehyde C12 MNA; Aldehyde C13; Citral; Pentylcinnamaldehyde α; Anisaldehyde-O; Anisaldehyde; Natural Benzaldehyde; Bergamotaldehyde; Boral; Bourgesinaldehyde; Camphoraldehyde; Citral; Citronellol HM; Citronelloloxyacetaldehyde; Citral E HM; Phenoxyacetaldehyde; Phenoxyacetaldehyde 50 PCT PEMOSA; Crotonaldehyde; Cuminaldehyde; Cyclamenaldehyde; Decadienaldehyde trans, trans-2,4, cis-4-decaldehyde; trans-2-decaldehyde; Natural trans-2-decaldehyde; trans-4-decaldehyde; Decaldehyde-9,1; Dodecenaldehyde 2,6; trans-2-dodecaldehyde; Dupical; 10% Triepoxydecenaldehyde-4,5-2; Ethylhexanal; Anthocyanins; Geraniol; Neojasmine aldehyde; HELIOPAN; Heliotropin; Heptapenal (trans, trans, 2-4); cis-4-heptenal; trans-2-heptenal; trans-2-hexenal; Hexylcinnamaldehyde α; Solanal; Hydroxycitronellal; Intrelevade Spec.; Isononanal; Isovaleral; Citral (H&R JS I); Lily of the Valley Aldehyde; Linolal; Neolily of the Valley Aldehyde; Majatal; Mandrinal; 10% TEC BHT; Mevlanal; Sweet METHODY: Citronellol; Methylbutanal; Methylcinnamaldehyde α; Methylphenylpentenal 4,2,2; Methylthiopropanal-3; Methyltridecaldehyde-1210%VT; Methyl-3-buten-2-al; Methyl-5-phenyl-2-hexen-2-al; MUGENAL 50DPG; Neocyclic citral; Nonadienal; trans, cis-2,6; cis-6-nonenal; trans-2-nonenal; 3 / 060251; trans-2-pentenal; perillaldehyde; phenylacetaldehyde; phenylbutenal trans-2,2; phenylpropanal; PINOACET ALDEHYDE; PROFRANESAL; propanal 2-(p-tolyl); propanal; PS-IRALDEINXNEU; saffron aldehyde; salicylaldehyde FG; silver aldehyde (SILVIAL); tetrahydrocitral; cis-2,2; p-tolyl aldehyde FG; tridecenal trans-2; trifenal; undecadienal-2,4; trans-2-undecenal; VERNALALDEHYDE; VERTOCITRAL; VERTOMUGAL; VERTIPRENAL; VETRAL ROH; Natural cinnamaldehyde (HM); Acetals: FLOROPAL; Heptanal diethyl acetal; Nonadienal diethyl acetal; OKOUMAL; Phenylacetaldehyde glycerol acetal; Phenylacetaldehyde dimethyl acetal; Esters: Jasmine pyran; Jasmine ester; Methyl dihydrojasmonate;

[0237] In another variation of the method according to the invention, the flavoring agent may also be encapsulated as a core material in the form of a single flavoring agent, wherein the core material, as an active substance, comprises at least one single flavoring agent or a mixture thereof.

[0238] Within the scope of this invention, typical examples of flavorings or spices that can be encapsulated are selected from the group consisting of: acetophenone; allyl hexanoate; α-ionone; β-ionone; anisaldehyde; anisyl acetate; anisyl formate; benzaldehyde; benzothiazole; benzyl acetate; benzyl alcohol; benzyl benzoate; β-ionone; butyl butyrate; butyl hexanoate; butyl phthalide; carvone; camphene; caryophyllene; eucalyptol; cinnamyl acetate; citral; citronellol; citronellol; citronellol acetate; cyclohexyl acetate; cymene; damascene styrosol; decanolactone; dihydrocoumarin; dimethyl anthranilate; dimethyl anthranilate; dodecylolactone; ethoxyethyl acetate; ethylbutyric acid; ethyl butyrate; ethyl decanoate; ethyl hexanoate; ethyl crotonate; ethyl furanone; ethyl guaiacol; ethyl isobutyrate; ethyl isovalerate; ethyl lactate; ethyl methylbutyrate; ethyl propionate; eucalyptol; ethyl heptaate; 4-(p-hydroxyphenyl)-2-butanone; γ-decanolactone; geraniol; geraniol acetate; geraniol acetate; grapefruitaldehyde; methyl dihydrojasmonate (e.g.) ); Heliotrope extract; 2-Hepenoyl; 3-Hepenoyl; 4-Hepenoyl; trans-2-Hepenoal; cis-4-Hepenoal; trans-2-Hexenal; cis-3-Hexenol; trans-2-Hexenoic acid; trans-3-Hexenoic acid; cis-2-Hexenyl acetate; cis-3-Hexenyl acetate; cis-3-Hexenyl hexanoate; trans-2-Hexenyl hexanoate; cis-3-Hexenyl carboxylate; cis-2-Hexyl acetate; cis-3-Hexyl acetate; trans-2-Hexyl acetate; cis-3-Hexyl carboxylate; p-Hydroxybenzylacetone; Isoamyl alcohol; Isoamyl isovalerate; Isobutyl butyrate; Isobutyraldehyde; Isoeugenol methyl ether; Isopropyl methylthiazole; Lauric acid; Acetylacetic acid; Linalool; Linalool oxide; Linaloyl acetate; Menthol; Thin Furan; Methyl anthranilate; Methylbutanol; Methylbutyric acid; Methyl butyl acetate; Methyl hexanoate; Methyl cinnamate; 5-Methylfurfural; 3,2,2-Methylcyclopentenolone; 6,5,2-Methylheptenone; Methyl dihydrojasmonic acid; Methyl jasmonic acid; 2-Methylbutyrate; 2-Methyl-2-pentenic acid; Methyl thiobutyrate; 3,1-Methylthiohexanol; 3-Methylthiohexyl acetate; Nerol; Nerol acetate; trans, trans-2,4-nonadienal; 2,4-nonadienol; 2,6-nonadienol; 2,4-nonadienol; Nocaketone; δ-octanolide; γ-octanolide; 2-octanol; 3-octanol; 1,3-octenol; 1-octanolate; 3-octanolate; Palmitic acid; Triacetaldehyde; Phyllanthrene; Pentyl Diketone; phenethyl acetate; phenethyl alcohol; phenethyl alcohol; phenoxyethyl isovalerate; piperaldehyde; propionaldehyde; propyl butyrate; longleaf menthone; menthol; sweet orange aldehyde; thiothiazole; terpinene; terpineol; terpinene oil; 8,3-thiomenthone; 4,4,2-thiomethylpentanone; thymol; δ-undecyl lactone; γ-undecyl lactone; sesquiterpene; valeric acid; vanillin; acetoin; ethyl vanillin; ethyl vanillin isobutyrate (3-ethoxy-4-isobutyryloxybenzaldehyde); 2,5-dimethyl-4-hydroxy-3(2H)-furanone and its derivatives (preferably cyclohomanthone (2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone), cyclohomanthone (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; γ-lactone (preferably γ-undecyllactone, γ-nonyllactone, γ-decyllactone); δ-lactone (preferably 4-methylδ-decyllactone, masoryllactone, δ-decyllactone, Tuberolacton); 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; isoamyl acetate; ethyl butyrate; n-butyl butyrate; isoamyl butyrate; 3-methylethyl butyrate; ethyl hexanoate;Allyl hexanoate; n-Butyl hexanoate; Ethyl n-Octaate; Ethyl 3-methyl-3-phenyl glycidyl ester; 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-aldehyde; Phenylacetaldehyde; 2-methyl-3-(methylthio)furan; 2-methyl-3-furanthiol; Bis(2-methyl) -3-Furfuryl) disulfide; furfuryl thiol; methylthiopropionaldehyde; 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-pyrrolidone; 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-Methyltridecaldehyde; 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; cinnamyl alcohol; methyl salicylate; isoprene; and stereoisomers, enantiomers, positional isomers, diastereomers, cis / trans isomers, or epimers of the above substances not explicitly mentioned herein, as well as mixtures thereof.

[0239] In another alternative embodiment of the invention, a fragrance mixture or flavoring oil or flavoring mixture or flavoring agent is used as the active substance or core material to be encapsulated in the microcapsules according to the invention. These are compositions containing at least one fragrance or flavoring agent. Such compositions, particularly fragrance mixtures or flavoring oils, preferably contain 2, 3, 4, 5, 6, 7, 8, 9, 10 or more fragrances.Preferably, the aromatic mixture or fragrance oil is selected from the group consisting of: extracts of natural raw materials; essential oils, extracts, absolutes, resins, resinoids, balsams, tinctures such as ambergris tincture; amygdalin oil; angelica seed oil; angelica root oil; fennel oil; perilla oil; valerian oil; basil oil; tree moss absolute; laurel oil; artemisia oil; benzoin resin; bergamot oil; beeswax absolute; birch tar; bitter almond oil; peppermint oil; basil leaf oil; caprova oil. Oils: Juniper berry oil; Sweet flag oil; Camphor oil; Canan oil; Cardamom oil; Calomel oil; Cinnamon oil; Acacia oil; Cactus absolute; Cedar leaf oil; Cedarwood oil; Rockrose oil; Citronella oil; Lemon oil; Copaiva balsam; Copaiva balsam oil; Coriander oil; Costus root oil; Cumin oil; Cypress oil; Artemisia oil; Dill oil; Dill seed oil; Eau de brouts. (absolute); Oakmoss absolute oil; Elemi resin oil; Tarragon oil; Lemon eucalyptus oil; Eucalyptus oil; Fennel oil; Spruce needle oil; Cedar needle oil; White pine resin oil; White pine resin; Geranium oil; Grapefruit oil; Guaiac oil; Ancient rue resin; Ancient rue resin oil; Immortelle absolute oil; Immortelle oil; Ginger oil; Orris root absolute oil; Orris root oil; Jasmine absolute oil; Sweet flag oil; Chamomile oil; Roman chamomile oil; Carrot oil Seed oil; Caragana oil; Pine needle oil; Curly peppermint oil; Coriander oil; Labdanum oil; Labdanum absolute; Labdanum resin; Mixed lavender absolute; Mixed lavender oil; Lavender absolute; Lavender oil; Lemongrass oil; Angelica pubescens oil; Distilled white lemon oil; Pressed white lemon oil; Linalool oil; Litsea cubeba oil; Laurel oil; Laurel leaf oil; Nutmeg oil; Marjoram oil; Orange oil; Massoir bark oil bark oil); mimosa absolute oil; musk seed oil; musk tincture; musk sage oil; nutmeg seed oil; myrrh absolute oil; myrrh oil; myrtle oil; clove leaf oil; clove flower oil; neroli oil; frankincense absolute oil; frankincense oil; saposhnikovia root oil; neroli absolute oil; orange oil; oregano oil; palmarosa oil; patchouli oil; perilla oil; Peruvian balsam oil; parsley leaf oil; parsley seed oil; bitter orange leaf oil; pepper oil; peppercorn oil; allspice oil; pine oil; peppermint oil; rose absolute oil; rosewood oil; rose oil; rosemary oil; Dalmatian sage oil; Spanish sage oil; sandalwood oil; celery seed oil; spicy lavender oil. (oils); star anise oil; styrax oil; marigold oil; fir needle oil; tea tree oil; turpentine oil; thyme oil; tolubalsam; tonka bean absolute oil; tuberose absolute oil; vanilla extract; violet leaf absolute oil; verbena oil; vetiver oil; juniper berry oil; wine yeast oil; wormwood oil; wintergreen oil; ylang-ylang oil; hyssop oil; civet absolute oil; cinnamon leaf oil; cinnamon bark oil and their fractions or separated components.

[0240] Most preferably, the fragrance or flavoring agent used in the method according to the invention is selected from the group consisting of: AGRUMEX LC; AGRUNITRIL; Aldehyde C11UNDEYLENIC; Aldehyde C12 lauric acid; Aldehyde C12 MNA; Aldehyde C14 SOG.; Aldehyde C16 SOG.; Allyl glycolate; Allyl hexanoate; Allyl cyclohexyl propionate; Allyl heptaate; 10TEC; Kristol 10% IPM; Ambroxol; Pineapple alcohol NAT.EX STERNANIS; Pure anisaldehyde; Benzyl acetone; Benzyl salicylate; Borneol L / Isobornol 65 / 35; Bacumber leaf oil; Citronellol 950; Lauronitrile; Cyclohexyl salicylate; Cymol Para Supra; Damask Delta; Dihydrolauryl alcohol; Dimethyl benzyl carbene butyrate; Dynascone; Ethylene brassinate; Ethyl methylbutyrate-2; Ethyl succinate; Natural eucalyptol; Eucalyptol 80 / 85%; Natural eugenol; Naturally aromatic sweet anise oil; FILBERTONE 10% IPM; FILBERTONE; FLOROPAL; GALBASCONE; Geraniol 60; Geranium; Herbs; Herbal medicines; Propionate oxalate; Hexyl cis-3-acetate; Hexyl cis-3-salicylate; Hexyl acetate; Hexyl acetate S; Hexyl isobutyrate; Hexyl salicylate; Isoamyl butyrate; Isoborneol acetate; Isopropyl methylbutyrate-2; Isocyanate 70; Java alcohol; Camphor DL; Cresol methyl ether P (CR < 10 PPM); Citrin; Privet aldehyde; Convallaria aldehyde; Linalool; Glyceryl acid; Cucurbitacin; Methylheptanol carbonate; Methylheptanol carbonate; Muscone; Neocyclic citral; Nerolin BROMELIA; Nerolin YARAYARA KRIST.; Nerolinone; Norlinol; Nerolin oil; ORIVONE; Ozolinone; Patchouli oil; Vegetable oil triglycerides; Phellandren fraction excluding eucalyptus oil; Phenylacetyl acetate; high cis-rose oxide; Styrene acetate; Terpenoids; Gamma; Tetrahydronaphthol; Timbersilk; Triethyl citrate; Methyldecenol; Vitocitric acid; Vertofix; K and a mixture of the above-mentioned active substances.

[0241] Exemplary cooling agents used as hydrophobic active substances in the preparation of microcapsules according to the present invention include one or more menthols 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), and menthyl esters (e.g., menthyl formate, menthyl acetate, menthyl isobutyrate). Esters, menthyl lactate, L-menthyl L-lactic acid ester, L-menthyl D-lactic acid ester, 2-methoxy-menthyl acetate, 2-methoxyethoxy-menthyl acetate, pyroglutamic acid menthyl acetate, menthyl carbonate (e.g., propylene glycol menthyl carbonate, ethylene glycol menthyl carbonate, glyceryl menthyl carbonate or mixtures thereof), half-esters of menthol with dicarboxylic acids or their derivatives (e.g., monomenthyl succinate, monomenthyl glutarate, monomenthyl malonic acid, o-menthyl succinate-N,N- 2,3-Dimethyl-2-(2-propyl)butyric acid derivatives (e.g., 2,3-dimethyl-2-(2-propyl)butyric acid ester ... N-formamide butyrate [WS23], isomenthol or its esters (1-(-)isomenthol, 1-(-)isomenthol acetate), menthol derivatives (e.g., p-menthol 3,8-diol), lentinanol or synthetic or natural mixtures containing lentinanol, pyrrolidine derivatives of cycloalkyl diones (e.g., 3-methyl)-2-(1-pyrrolyl)-2-cyclopenten-1-one or tetrahydropyrimidine-2-one (e.g., icerin or the related compounds described in WO 2004 / 026840). Other cooling agents include menthol (L-menthol, D-menthol, racemic menthol, isomenthol, neo-isomenthol, neomenthol), L-menthyl methyl ether, menthyl formate, menthyl acetate, menthone, isomenthol, L-(-)isomenthol acetate) and lentinanol, which have flavor effects. Suitable cooling agents are well known in the art, for example, as described in US 2017 / 216802(A1), US2010 / 273887(A1), EP 2033688(A2) and EP 1958627(A2).

[0242] In another variant, TRPV1 or TRPV3 modulators are used as the active material or core material to be encapsulated in the polyurea / polyurethane microcapsules according to the invention. TRPV1 and TRPV3 modulators are known in the art and are associated with TRP channels (transient receptor potential channels) of the vanilloid (TRPV) subfamily. TRPV1 modulators impart a spicy taste and a hot sensation associated with capsaicin and piperine. TRPV3 proteins belong to a family of nonselective cation channels that function in various processes, including temperature sensing and vasomotor regulation. TRPV3 channels can be directly activated by various natural compounds, such as carvacrol, thymol, and eugenol. Other monoterpenoids, which either induce a hot sensation or act as skin sensitizers, can also open the channels. Monoterpenoids can also induce agonist-specific desensitization of TRPV3 channels in a calcium-independent manner.

[0243] In another variant, the polyurea / polyurethane microcapsules according to the invention use an active substance as the encapsulating active substance or as the core material, the active substance being selected from the group consisting of substances that cause an irritating taste or heat or hot sensation on the skin or mucous membranes, or a tingling or numbing sensation in the mouth or throat, or a substance having an irritating or spicy or astringent effect.

[0244] Preferably, the active substance causing heat or spiciness is selected from the group consisting of: red chili powder, chili powder, chili extract, red chili extract, pepper extract, chili extract, ginger root extract, bird's eye chili extract (Aframomum melegueta), golden button extract (golden button oleracea; Spilanthes acmella or Spilanthes oleracea), Japanese pepper extract (Zanthoxylum piperitum), galangal extract, galangal extract, and water pepper extract (Polygonium) hydropiper), capsaicinoids, especially capsaicin, dihydrocapsaicin or vanillonamide; gingerol, especially gingerol-[6], gingerol-[8], or gingerol-

[10] ; gingerol, especially gingerol-[6], gingerol-[8], gingerol-

[10] ; ginger dione, especially ginger dione-[6], ginger dione-[8] or ginger dione-

[10] ; paradole, especially gingerol-[6], gingerol-[8] or gingerol-

[10] ; dehydro ginger diones, especially dehydro ginger dione-[6], dehydro ginger dione-[8] or dehydro ginger dione-

[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.

[0245] Preferably, the active substance that can be perceived as irritating or stinging is selected from the group consisting of: aromatic isothiocyanates, especially phenylethyl isothiocyanate, allyl isothiocyanate, cyclopropyl isothiocyanate, butyl isothiocyanate, 3-methylthiopropyl isothiocyanate, 4-hydroxybenzyl isothiocyanate, 4-methoxybenzyl isothiocyanate and mixtures thereof.

[0246] Preferably, the active substance causing the stinging sensation is selected from the group consisting of: 2E,4E-decadienoic acid-N-isobutylamide (trans-sawtooth pyrethrin), particularly as described in WO 2004 / 043906; 2E,4Z-decadienoic acid-N-isobutylamide (cis-sawtooth pyrethrin), particularly WO The following are described in 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-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-piperidine (achilleamide); 2E,4E-decadienoic acid-N-piperidine (sarmentin); 2E-decadienoic acid-N-isobutyramide; 3E-decadienoic acid-N-isobutyramide; 3E-nonenoic acid-N-isobutyramide; 2E,6Z,8E-decadienoic acid-N-isobutyramide (Cypericum amide); 2E,6Z,8E-decadienoic acid-N-([2S]-2-methylbutyl)amide (High-Cypericum amide); 2E,6Z,8E-decadienoic acid-N-([2R]-2-methylbutyl)amide; 2E-decen 4-acid-N-isobutyramide; 2Z-decen 4-alkynic acid-N-isobutyramide; 2E,6Z,8E,10E-Dodecanotraenoic acid-N-(2-methylpropyl)amide (α-sanshozolin); 2E,6Z,8E,10E-Dodecanotraenoic acid-N-(2-hydroxy-2-methylpropyl)amide (α-hydroxysanshozolin); 2E,6E,8E,10E-Dodecanotraenoic acid-N-(2-hydroxy-2-methylpropyl)amide (γ-hydroxysanshozolin);

[0247] 2E,4E,8Z,10E,12E-Tetradecanoic acid-N-(2-hydroxy-2-methylpropyl)amide (γ-hydroxypiperidine);

[0248] 2E,4E,8E,10E,12E-Tetradecanoic acid N-(2-hydroxy-2-methylpropyl)amide (γ-hydroxyisopiperidine);

[0249] 2E,4E,8Z,10E,12E-Tetradecanoic acid N-(2-methyl-2-propenyl)amide (γ-dehydropiperidine);

[0250] 2E,4E,8Z,10E,12E-tetradecanoic acid N-(2-methylpropyl)amide (γ-sanzoin); 2E,4E,8Z,11Z-tetradecanoic acid-N-(2-hydroxy-2-methylpropyl)amide (bungeanool); 2E,4E,8Z,11E-tetradecanoic acid-N-(2-hydroxy-2-methylpropyl)amide (isosanzoin); 2E,4E,8Z-tetradecanoic acid-N-(2-hydroxy-2-methylpropyl)amide (dihydrosanzoin); and 2E,4E-tetradecadienoic acid-N-(2-hydroxy-2-methylpropyl)amide (tetrahydrosanzoin) and mixtures thereof.

[0251] Preferably, the active substance with astringent properties is selected from the group consisting of: catechins, especially epicatechin, gallocatechin, epigallocatechin and their respective gallic esters, especially epigallocatechin gallic ester or epicatechin gallic ester, their oligomers (proanthocyanidins, proanthocyanidins, prodeltacyanidins, procyanirin, thearubigenin, thearubigin) and their C- and O-glycosides; dihydroflavonoids, such as dihydromyricetin, taxine and their C- and O-glycosides; flavonols, such as myricetin, quercetin and their C- and O-glycosides, such as quercetin, rutin; gallic esters of carbohydrates, such as tannins; pentagalloglucose or their reaction products, such as elligatannin; aluminum salts, such as alum and mixtures thereof.

[0252] In another variation of the first and / or second aspect of the invention, the biological principle may also be encapsulated as a nuclear material, wherein the nuclear material comprises at least one biological principle or a mixture thereof.

[0253] Biological principles refer to bioactive substances such as tocopherol, tocopheryl acetate, tocopheryl palmitate, ascorbic acid, carnotine, carnosine, caffeine, (deoxy)ribonucleic acid and its cleavage products, beta-glucan, retinol, bisabolol, allantoin, phyttrium, panthenol, AHA acid, amino acids, ceramides, pseudoceramides, essential oils, plant extracts and vitamin complexes.

[0254] In another variation of the method according to the invention, the paper printing coating material is also used as the active material to be encapsulated or as the core material, as described in US 2800457A, the related disclosure of which is incorporated herein by reference in its entirety.

[0255] Relative to the total weight of the internal non-aqueous phase, the internal non-aqueous phase may comprise, for example, 20 to 80 wt%, preferably 25 to 75 wt%, or even more preferably 33 to 50 wt% of the hydrophobic active material to be encapsulated, 0.1 to 5 wt%, preferably 0.15 to 3.5 wt%, or even more preferably 0.5 to 2.5 wt% of a first crosslinking agent, and 100% of a hydrophobic solvent.

[0256] Therefore, the method of the present invention can achieve a high loading of active substances in the microcapsules according to the present invention.

[0257] In another step (ii) of the method according to the invention, an external aqueous phase comprising at least one protein and / or at least one polysaccharide, and optionally at least one protective colloid, is provided.

[0258] Suitable solvents for preparing the external aqueous phase are water or a mixture of water and at least one water-soluble organic solvent. Suitable organic solvents include, for example, glycerol, 1,2-propanediol, 1,3-propanediol, ethylene glycol, diethylene glycol, triethylene glycol, and the like. However, water is the preferred solvent.

[0259] According to the present invention, at least one protein is selected from the group consisting of: protein L-amino acids, animal or plant proteins, especially protein isolates, fragments of animal or plant proteins, partial or complete hydrolysates of proteins or intermediates of proteins produced by physicochemical processes or fermentation or enzymatic treatment, especially proteins of the following categories: meat (mammals, birds, reptiles, amphibians, fish), crustaceans, shellfish, bivalves, mollusks, insects, eggs, dairy products, especially casein and whey, rennet casein, whey protein concentrate 80%, gelatin, algae, cereals, especially wheat, barley, rye, spelt wheat, gluten, especially wheat gluten, rapeseed, sunflower, rice, potato, corn, soybean, legumes, peas, lentils, lupins, peanuts, alfalfa, hemp, other proteins derived from edible plants, chitosan and mixtures thereof.

[0260] Among the proteins mentioned above, gelatin, milk protein, whey protein, and pea protein are particularly preferred.

[0261] The amino acids are L-amino acids of proteins. L-amino acids are selected from the group consisting of the following: 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.

[0262] Of the amino acids mentioned above, L-glutamine and L-lysine are particularly preferred.

[0263] In preferred variants, one of the aforementioned proteins is used in combination with one or more free L-amino acids. A preferred combination is milk protein with L-glutamine and / or L-lysine. This combination allows both macromolecules and small molecules to be incorporated into the network, thereby increasing stability. Furthermore, the amino acids L-glutamine and / or L-lysine are particularly easily cross-linked by enzymatic cross-linking agents (such as transglutaminase).

[0264] The aforementioned proteins possess the advantageous effect of emulsification. This emulsifying action helps stabilize emulsions. Due to their more or less flexible structure and varying charged regions within the molecule, proteins are amphiphilic and therefore possess surface activity. The secondary and / or tertiary structures of the molecule can be altered by modifying the protein, for example through physical or chemical modifications. Thus, emulsifying properties can be influenced by changing the spatial availability of charged regions within the molecule or by exposing amino acid side chains. Because of these advantageous properties, additional emulsifiers or protective colloids can be omitted in the method according to the invention.

[0265] The content of at least one protein in the external aqueous phase is in the range of 0.25 to 5.0% by weight, preferably in the range of 0.5 to 3.0% by weight, relative to the total weight of the external aqueous phase. Most preferably, the amount of at least one protein is in the range of 1.0 to 1.5% by weight, relative to the total weight of the external aqueous phase.

[0266] According to the first and second aspects of the present invention, the at least one polysaccharide is selected from the group consisting of:

[0267] - Indigestible fiber and dietary fiber, especially insoluble dietary fiber, particularly cellulose, cellulose derivatives such as hydroxyethyl cellulose, especially quaternized hydroxyethyl cellulose, carboxymethyl cellulose (CMC) and microcrystalline cellulose (MCC), hemicellulose, lichen polysaccharides, chitin, chitosan, lignin, xanthan gum, plant fiber, especially cereal fiber, potato fiber, apple fiber, citrus fiber, bamboo fiber, extracted beet fiber, oat fiber and soluble dietary fiber, especially inulin, especially native inulin, highly soluble inulin, granular inulin, high-performance inulin, pectin, alginate, agar, carrageenan, gum arabic (Senegal type and Seyal type), konjac gum, gellan gum, gelling polysaccharides (parastarch) guar gum, carob gum, xanthan gum, raffinose, xylose, polydextrose and lactose;

[0268] - Starch, particularly starches derived from wheat, potatoes, corn, rice, cassava, and oats; modified starches and starch derivatives, such as dextrins or maltodextrins, particularly dextrins and maltodextrins derived from wheat, potatoes, corn, rice, and oats, especially maltodextrins DE8-10, DE17-20, and DE18-20; cyclodextrins; oligosaccharides, particularly fructooligosaccharides; and

[0269] - Sugar alcohols, especially sorbitol, mannitol, isomaltitol, maltitol, maltitol syrup, lactitol, xylitol and erythritol;

[0270] -glucose,

[0271] And mixtures of the two or more of the above polysaccharides.

[0272] Among the polysaccharides mentioned above, gum arabic and maltodextrin are particularly preferred. The most preferred are maltodextrin DE8-10 for potato, DE17-20 for corn, DE17-20 for potato, and DE18-20 for wheat.

[0273] The content of at least one polysaccharide in the external aqueous phase is in the range of 0.5 to 7.0% by weight, preferably in the range of 1.5 to 6.0% by weight, relative to the total weight of the external aqueous phase. Most preferably, the amount of at least one polysaccharide is 3.0 to 5.0% by weight, relative to the total weight of the external aqueous phase.

[0274] Preferably, the external aqueous phase provides the two main components of the capsule shell: at least one protein and at least one polysaccharide. When the protein and polysaccharide are used in combination, a soluble or insoluble protein-polysaccharide complex is formed. The resulting emulsion is less prone to aggregate formation, thus eliminating the need for the addition of protective colloids or additional emulsifiers in the method according to the invention.

[0275] The following combinations of proteins and polysaccharides are particularly preferred for constructing capsule walls or capsule shells: whey protein and maltodextrin, milk protein and maltodextrin, whey protein and gum arabic, and gelatin and maltodextrin; milk protein, L-glutamine, L-lysine and maltodextrin; and gelatin, milk protein and maltodextrin.

[0276] The most preferred materials for constructing the capsule shell are a combination of gelatin and maltodextrin DE8-10 potato starch, or a combination of milk protein, L-glutamine and / or L-lysine and maltodextrin. Microcapsules prepared using these shell materials have a free oil content of ≤1% in isopropanol.

[0277] The components described above and exemplified for constructing the capsule wall, namely proteins and polysaccharides, are readily available from biological sources. Furthermore, such components are also readily biodegradable.

[0278] In another variant of the method according to the invention, an external aqueous phase is provided containing only one of the main components, the capsule shell protein or polysaccharide. In this variant, the addition of the other main component, polysaccharide or protein, is optionally carried out in step (iv) after emulsification / dispersion, before or simultaneously with the addition of the catalyst in step (v).

[0279] Compared to existing microcapsules with high polyisocyanate content, the content of polyisocyanates as cross-linking agents in the capsule shell can be reduced by using at least one protein and at least one polysaccharide. Preferably, the isocyanate content does not exceed 50% by weight relative to the capsule shell, and even more preferably, the isocyanate content does not exceed 20% by weight. By replacing polyisocyanates with proteins and / or polysaccharides as components for constructing the capsule wall or capsule shell, the polyisocyanate content in the microcapsules is reduced, resulting in a lower degree of cross-linking.

[0280] Surprisingly, however, this lower degree of cross-linking leads to both stable microcapsules and microcapsules with better biodegradability, as illustrated in the following examples.

[0281] Optionally, a protective colloid may be added to the external aqueous phase.

[0282] Protective colloids are polymer systems that prevent the aggregation (agglomeration, coagulation, and flocculation) of emulsified, suspended, or dispersed components in suspensions or dispersions. During dissolution, protective colloids bind a large amount of water and, depending on their concentration, produce high viscosity in aqueous solutions. In the preparation of oil-in-water emulsions, the hydrophobic portion of the protective colloid adheres to the primary particles, while its polar, i.e., hydrophilic, molecular portion is directed towards the aqueous phase. Through this interfacial attachment, the protective colloid reduces interfacial tension and inhibits the aggregation of primary particles. Furthermore, the protective colloid stabilizes the emulsion, which in this case promotes the formation of relatively small droplets, thereby also promoting the formation of corresponding microcapsules.

[0283] Within the scope of the method according to the invention, the protective colloid, in addition to the above-described properties, also possesses emulsifying properties. If the emulsifying properties of the protective colloid (e.g., carboxymethyl cellulose, acid-modified starch, polyvinyl alcohol, ammonium salt derivatives of polyvinyl alcohol, polystyrene sulfonate, polyvinylpyrrolidone, polyvinyl acrylate, etc.) are sufficient, then in the method according to the invention, it is even advantageous not to use an emulsifier in the downstream emulsification or dispersion step (iii).

[0284] The protective colloid used in the method according to the present invention is selected from the group consisting of:

[0285] -diols, especially ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, isobutanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-dodecanediol, and

[0286] - Polyols, preferably triols, especially glycerol and its ethoxylated and propoxylated products, trimethylolpropane and its ethoxylated and propoxylated products; polyvinyl alcohol (PVOH) and its derivatives, especially polyvinyl alcohol with ammonium or sulfonate functionalization; polyphenols, preferably 1,3,5-trihydroxybenzene; polysaccharides, especially glucose, starch or chemically, mechanically and / or enzymatically modified starch, cellulose derivatives; for example hydroxyethyl cellulose, especially quaternized hydroxyethyl cellulose and carboxymethyl cellulose.

[0287] - Polyvinylpyrrolidone, vinyl maleate copolymer, sodium lignosulfonate, maleic anhydride / styrene copolymer, ethylene / maleic anhydride copolymer, copolymer of ethylene oxide, propylene oxide and polyethoxylated sorbitol, sodium dodecyl sulfate

[0288] -Animal and plant polymers, especially gum arabic (Senegal and Serian types), proteins, gelatin, mastic resin, shellac, lignin, chitosan, saponins

[0289] And mixtures of the above compounds.

[0290] Starch, especially modified starch, or animal or plant polymers, are biodegradable natural substances. Combined with the polyisocyanates described herein, this method can thus provide bio-based and biodegradable capsule shells. Therefore, in the method according to the invention, starch and animal / plant polymers also act as so-called biocrosslinking agents.

[0291] The starch used in the method according to the present invention is selected from the group consisting of: corn starch, potato starch, rye starch, wheat starch, barley starch, oat starch, rice starch, pea starch, tapioca starch, and mixtures thereof.

[0292] Chemically modified starch is preferably acid-modified starch, alkali-modified starch, oxidized starch, acetylated starch, succinate-esterified starch, or octenyl succinate-esterified starch.

[0293] Preferably, the external aqueous phase comprises at least one protective colloid selected from polyvinylpyrrolidone, polyvinyl alcohol, and mixtures thereof. Polyvinylpyrrolidone is particularly preferred. Commercially available polyvinylpyrrolidone has a molecular weight between about 2,500 and 750,000 g / mol.

[0294] Even more preferably, polyols, polyphenols, or starch, especially modified starch, are used as protective colloids. Particularly preferred are polyvinyl alcohol or its ammonium salt derivatives, 1,3,5-trihydroxybenzene, or starch, modified starch, or carboxymethyl cellulose as protective colloids for preparing the microcapsules according to the invention.

[0295] According to the present invention, combinations of two or more different protective colloids can also be used to prepare microcapsules according to the present invention.

[0296] It has been found that, in the method according to the invention, it is particularly advantageous to use a combination of one of the aforementioned protective colloids with starch as another protective colloid in the external aqueous phase. This combination stabilizes the emulsion due to the large number of functional hydroxyl groups, and on the other hand, facilitates the reaction between the protective colloid and the polyisocyanate, wherein the reaction equilibrium shifts towards the product (i.e., polyurethane) in the reaction between the protective colloid and the polyisocyanate. Furthermore, the large number of functional hydroxyl groups in starch also enables the formation of particularly pronounced spatial crosslinks.

[0297] Depending on the number of functional groups and / or the size of the protective colloid, the aforementioned protective colloid exhibits different reaction rates with the isocyanate groups of at least one polyisocyanate. For example, glycerol reacts with the isocyanate groups faster than starch due to its size. Therefore, the crosslinking of the protective colloid with the isocyanate groups of the polyisocyanate can be controlled by selecting the protective colloid.

[0298] Combinations of glycerol with starch or modified starch, or glycerol with quaternized hydroxyethyl cellulose or Seychelles-type gum arabic, have proven to be particularly advantageous. These combinations utilize the properties of both of these protective colloids: the high reaction rate of glycerol and the abundance of polymerizable functional groups in the other protective colloids.

[0299] The protective colloid used in the method according to the present invention has a dual function: on the one hand, it acts as a protective colloid to prevent the agglomeration of emulsified, suspended or dispersed components, stabilizes the subsequently formed emulsion, facilitates the formation of small droplets, and stabilizes the final microcapsule dispersion.

[0300] Therefore, relative to the total weight of the external aqueous phase, the amount of protective colloid used or the amount of protective colloid combination used is in the range of 1 to 6% by weight, preferably in the range of 2 to 4% by weight, and even more preferably in the range of 2 to 3% by weight.

[0301] Preferably, the external aqueous phase is prepared under stirring by adding polysaccharides and / or proteins, and optionally protective colloids, sequentially or in reverse order to the external aqueous phase, or by adding all components to the external aqueous phase simultaneously.

[0302] To improve protein solubility, the pH of the external aqueous phase can be optionally adjusted to a pH value below the isoelectric point of the protein, i.e., below the isoelectric point of the protein used.

[0303] The isoelectric point is understood as the pH value at which an isoelectric state is achieved, that is, the pH value at which the positive and negative charges are balanced in an amphoteric electrolyte or amphoteric ion (such as amino acids and proteins). This value is a characteristic constant for each amino acid and depends on the pK of the functional group. s Value. Besides amino acids, peptides and proteins also have isoelectric points. At their isoelectric points, amino acids and proteins have the lowest water solubility.

[0304] Preferably, the pH of the aqueous phase is adjusted to a pH value in the range of 2.0 to 7.0, more preferably in the range of 2.0 to 6.0, and most preferably in the range of 3.0 to 5.0, which is slightly acidic. Adjusting the pH value below the isoelectric point, i.e., below the isoelectric point of the protein, has the advantage that the emulsifying properties and solubility of the protein are maximized at such pH values.

[0305] The pH of the external aqueous phase is adjusted by adding an organic acid. Therefore, prior to the emulsification step, an organic acid, such as formic acid or acetic acid, is added to the external aqueous phase, and the pH is adjusted to the range described above.

[0306] An internal non-aqueous phase comprising at least one first crosslinking agent and at least one hydrophobic active substance is emulsified or dispersed in an external aqueous phase in a further method step (iii) to form an oil-in-water emulsion / dispersion.

[0307] Oil-in-water emulsions are prepared by mixing an internal non-aqueous phase and an external aqueous phase. The weight ratio of the internal non-aqueous phase to the external aqueous phase is preferably in the range of 70:30 to 60:40, and more preferably in the range of 30:70 to 60:40.

[0308] In order to promote the formation of an emulsion or dispersion consisting of an internal non-aqueous phase and an external aqueous phase, stabilize the formed emulsion or dispersion, and prevent the separation of the internal non-aqueous phase (oily / organic / hydrophobic) from the external aqueous phase (hydrophilic), in the method according to the invention, a stabilizer and / or an emulsifier or emulsifying aid may optionally be added to the emulsion or dispersion.

[0309] Preferably, a stabilizer for stabilizing the emulsion / dispersion is added to the external aqueous phase to prevent the internal non-aqueous phase (oily) from separating from the external aqueous phase.

[0310] Preferred stabilizers for preparing polysaccharide and protein-based microcapsules according to the present invention are primarily acrylic acid copolymers having sulfonic acid groups. Copolymers of acrylamide and acrylic acid, copolymers of alkyl acrylates and N-vinylpyrrolidone, such as… K15, K30 or K90 (BASF), sodium polycarboxylate, sodium polystyrene sulfonate, vinyl and methyl vinyl ether-maleic anhydride copolymers and ethylene, isobutylene or styrene-maleic anhydride copolymers, microcrystalline cellulose (commercially available, e.g., as...) (Names), diutan gum, xanthan gum, or carboxymethyl cellulose.

[0311] The amount of stabilizer relative to the external aqueous phase can be in the range of 0.01 to 10% by weight, preferably in the range of 0.1 to 3% by weight.

[0312] Optionally, an emulsifier, preferably an O / W type emulsifier, is used in the method according to the invention to enable the oil droplets in the internal non-aqueous phase to be uniformly distributed in the external aqueous phase and to stabilize the emulsion. Similarly, this is applicable to mixing solid, insoluble active substances in the external aqueous phase to stabilize the resulting dispersion.

[0313] When proteins or protective colloids have little or no emulsifying properties, the addition of an emulsifier is particularly advantageous. If emulsified proteins and / or protective colloids are used, an emulsifier may be advantageously omitted in the method according to the invention.

[0314] For example, nonionic surfactants from at least one of the following groups can be used as emulsifiers:

[0315] -2 to 30 moles of ethylene oxide and / or 0 to 5 moles of propylene oxide with straight-chain fatty alcohols having 8 to 22 carbon atoms, fatty acids having 12 to 22 carbon atoms, alkylphenols having 8 to 15 carbon atoms in the alkyl group, and alkylamines having 8 to 22 carbon atoms in the alkyl residue.

[0316] - Alkyl and / or alkenyl oligosaccharides and their ethoxylated analogs having 8 to 22 carbon atoms in alkyl (alken) residues;

[0317] -1 to 15 moles of the addition product of ethylene oxide with castor oil and / or hydrogenated castor oil;

[0318] -15 to 60 moles of the addition product of ethylene oxide with castor oil and / or hydrogenated castor oil;

[0319] - Partial esters formed by glycerol and / or sorbitol with unsaturated straight-chain 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.

[0320] - Polyglycerol (average degree of self-condensation 2 to 8), polyethylene glycol (molecular weight 400 to 5000), trimethylolpropane, pentaerythritol, sugar alcohols (such as sorbitol), alkyl glucosides (such as methyl glucoside, butyl glucoside and dodecyl glucoside), polyglucosides (such as cellulose) and esters formed from saturated and / or unsaturated straight-chain 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 Partial esters;

[0321] - A mixture of pentaerythritol, fatty acids, citric acid and fatty alcohols and / or a mixture of fatty acids, methyl glucose and polyols (preferably glycerol or polyglycerol) having 6 to 22 carbon atoms.

[0322] - Mono-, di-, and trialkyl phosphates, as well as mono-, di-, and / or triethylene glycol alkyl phosphates and their salts;

[0323] - Lanolin;

[0324] - Polysiloxane-polyalkyl-polyether copolymers and their derivatives;

[0325] Block copolymers, such as polyethylene glycol 30 dimer hydroxystearate;

[0326] Polymer emulsifiers, such as Goodrich's Pemulen type (TR1, TR2) or Cognis's... SP;

[0327] - Polyalkylene glycols and glyceryl carbonates.

[0328] Typical anionic emulsifiers that can be used in the method of the present invention to prepare isocyanate-based microcapsules are 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.

[0329] Furthermore, in the method for preparing polysaccharide and protein-based microcapsules according to the present invention, zwitterionic surfactants can be used as emulsifiers. Zwitterionic surfactants are surface-active compounds that carry at least one quaternary ammonium group and at least one carboxyl group and one sulfonate group in their molecules. Particularly suitable zwitterionic surfactants are so-called betaines, such as N-alkyl-N,N-dimethylglycinine ammonium (e.g., cocoalkyldimethylglycinine ammonium), N-acylaminopropyl-N,N-dimethylglycinine ammonium (e.g., cocoylaminopropyldimethylglycinine ammonium), and 2-alkyl-3-carboxymethyl-3-hydroxyethylimidazoline having 8 to 18 carbon atoms in each of the alkyl or acyl groups, as well as cocoylaminoethylhydroxyethylcarboxymethylglycine. Particularly preferred are fatty acid amide derivatives known as cocamidopropyl betaine, named CTFA.

[0330] Amphoteric surfactants are also suitable emulsifiers. An amphoteric surfactant is a surface-active compound that, in addition to a C8 / 18 alkyl or acyl group in its molecule, contains at least one free amino group and at least one carboxyl group (-COOH) or sulfonic acid group (-SO3H) and can form an inner salt. Examples of suitable amphoteric surfactants are N-alkylglycine, N-alkylpropionic acid, N-alkylaminobutyric acid, N-alkyliminodipropionic acid, N-hydroxyethyl-N-alkylamidopropylglycine, N-alkyltaurine, N-alkylsarcosine, 2-alkylaminopropionic acid, and alkylaminoacetic acid, each alkyl group having about 8 to 18 carbon atoms. Particularly preferred amphoteric surfactants are N-cocoalkylaminopropionate, cocoylaminoethylaminopropionate, and C12 / 18-acylsarcosine.

[0331] Finally, cationic surfactants can also be used as emulsifiers, particularly ester quaternary ammonium salts, preferably methyl quaternized di-fatty acid triethanolamine ester salts, quaternized hydroxyethyl cellulose, propylene glycol-modified and epichlorohydrin-quaternized chitosan, distearate dimethyl ammonium chloride (DSDMAC), benzalkonium chloride, benzethonium chloride, hexadecyl ammonium chloride, hexadecylpyridine chloride, hexadecyltrimethylammonium bromide (cetrimonium bromide), and dequalinium chloride.

[0332] The emulsifier may be added to the external aqueous phase in an amount of about 0.5 to about 10% by weight, and preferably about 1 to about 5% by weight, relative to the total weight of the external aqueous phase.

[0333] Emulsion formation (in the case of liquid active ingredients) or dispersion formation (in the case of solid active substances) involves the emulsification or dispersion of an internal non-aqueous or oily phase with an external aqueous or hydrophilic phase, carried out under high turbulence or high shear forces, where the intensity of the turbulence or shear force determines the diameter of the resulting microcapsules. Microcapsule preparation can be continuous or discontinuous. The capsule size typically decreases as the viscosity of the aqueous phase increases or the viscosity of the oil phase decreases.

[0334] The method according to the invention for preparing polysaccharide and protein-based microcapsules can, for example, be carried out using an "inline" technique. In this case, the internal non-aqueous phase and the external aqueous phase are first fed separately into an emulsifying turbine using forced metering pumps, and then combined shortly before entering the emulsifying turbine, or combined within the emulsifying turbine, at a throughput of 1200 to 1500 liters per hour. Furthermore, the method according to the invention for preparing polysaccharide and protein-based microcapsules can also be carried out in a conventional dispersion or emulsification apparatus.

[0335] To prepare the microcapsules according to the invention, emulsification or dispersion of the external aqueous phase and the internal non-aqueous phase is carried out, for example, by means of an emulsifying turbine (IKA Eurostar 20 high-speed stirrer).

[0336] The emulsification or dispersion process in the method according to the invention is advantageously carried out at a stirring speed of 1000 rpm to 5000 rpm, preferably 3000 rpm to 4000 rpm, for 30 seconds to 20 minutes, preferably 1 to 4 minutes, particularly preferably 1 to 2.5 minutes, until the capsule size is adjusted to 10 to 50 ± 5 micrometers.

[0337] After the emulsification or dispersion step (iii) is completed, there is an oil-in-water emulsion or dispersion in which the internal oil phase containing the active substance to be encapsulated is finely emulsified or dispersed in the external aqueous phase in the form of droplets.

[0338] In another variant of the method according to the invention, as described above, after the emulsification or dispersion step (iii), optionally at least one polysaccharide or at least one protein is added in step (iv). If the external aqueous phase provided in step (ii) has only at least one protein as a major component, then at least one polysaccharide is added in step (iv). And if the external aqueous phase provided in step (ii) has only at least one polysaccharide as a major component, then at least one protein is added in step (iv). The result of these additions is the formation of multiple layers (“layer-by-layer”), wherein the individual layers are cross-linked with each other in a subsequent step (v). In this way, for example, the charge of the emulsion can be controlled, thereby controlling the stability of the aggregation.

[0339] Alternatively, another protein and / or polysaccharide may be added in method step (iv), which may be the same as or different from at least one protein and / or at least one polysaccharide in method step (ii), or have a different charge or change charge upon pH change. By adding another protein and / or polysaccharide, additional layers (“layer-by-layer”) are constructed, wherein the individual layers are cross-linked with each other in subsequent method step (v). This results in a denser and more stable network of capsule wall components, thereby making the capsule shell more stable and thus increasing the stability of the microcapsules.

[0340] Another protein and / or another polysaccharide is selected from the proteins and / or polysaccharides that have been defined in detail in step (ii) of the method above. This also applies to preferred variants or preferred combinations of the proteins and / or polysaccharides described herein.

[0341] In a subsequent method step (v) according to the method of the invention, the material of the capsule shell or capsule wall is also first cross-linked under stirring.

[0342] Following emulsification or dispersion, a first crosslinking process is initiated by adding a catalyst, causing the layers of the capsule wall components to crosslink (“layer-by-layer”), thereby stabilizing the resulting capsule shell. In this process, the catalytic polymerization reaction between the carboxyl and / or sulfate groups and / or hydroxyl groups of the polysaccharide and / or the amino groups of the protein, and the isocyanate groups of the first crosslinking agent, occurs at the interface between the external aqueous phase and the dispersed internal phase, i.e., at the interface surrounding the emulsified or dispersed oil droplets containing the active material to be encapsulated.

[0343] Due to the catalytic cross-linking between the functional groups of at least one polysaccharide and / or at least one protein in the aforementioned layers and the functional groups of the first cross-linking agent, a first cross-linking unit or a first cross-linking matrix for constructing the capsule shell or capsule wall is formed.

[0344] In the method according to the invention, the construction of the first crosslinking unit is based on an addition polymerization reaction between the polysaccharide and the first crosslinking agent and / or the protein and the first crosslinking agent. In this process, the hydroxyl groups of the polysaccharide react with the isocyanate groups of the first crosslinking agent to form a polyurethane, while the amino groups of the protein react 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 in the first crosslinking step (v) to construct the capsule wall matrix or capsule shell.

[0345] The more cross-linked functional groups a capsule wall component (building block) has, the greater its spatial cross-linking degree, resulting in a denser and more stable capsule shell or wall. Besides the number of functional groups, the chain length of individual capsule wall components (building blocks) also significantly affects the mechanical properties of microcapsules, i.e., their stability: for example, the large number of hydroxyl groups in starch can form particularly pronounced spatial cross-links; longer-chain capsule wall components (building blocks), such as polyisocyanates, lead to a more stable capsule wall.

[0346] By constructing a first crosslinking matrix or a first crosslinking unit, a core material is present at the interface. That is, the emulsified or dispersed oil droplets of the encapsulated active substance are encapsulated by the external crosslinking matrix or crosslinking unit, thereby generating a capsule wall, making it difficult for the encapsulated active substance to diffuse.

[0347] Adding at least one catalyst to an emulsion or dispersion accelerates the cross-linking reaction between polysaccharides and / or proteins and cross-linking agents, and catalyzes reactions that favor the formation of the first cross-linking matrix or cross-linking unit.

[0348] The catalyst added in the method according to the 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 in the preparation of polyurethane plastics. Tertiary amines with free electron pairs favor the reaction between the isocyanate groups of the first crosslinking agent and the hydroxyl groups of the polysaccharide.

[0349] In addition to DABCO, catalysts such as bismuth- or tin-based catalysts are used to catalyze the initial crosslinking, such as catalysts based on bismuth(II) salts or bismuth(III) salts, as described in K. C. Risch & L. P. Rumao, Catalysis in Isocyanate Reactions, Polymer Reviews, 1970, 5:1, pp. 103-149, DOI:10.1080 / 15583727008085365, the entire disclosure of which is incorporated herein by reference.

[0350] According to the present invention, a combination of DABCO and one of the above-described catalysts is preferred. This mixture results in a multiplication of reactivity, as illustrated in K. C. Risch & L. P. Rumao, Catalysis in Isocyanate Reactions, Polymer Reviews, 1970, 5:1, pp. 103-149, DOI:10.1080 / 15583727008085365, the entire disclosure of which is incorporated herein by reference.

[0351] In the method according to the invention, DABCO and the above-described catalyst preferably catalyze the reaction of at least one polymerizable polyisocyanate having two or more isocyanate groups with a diol or polyol to form a polyurethane.

[0352] The amount of catalyst added to the external aqueous phase relative to the total weight of the external aqueous phase is in the range of 0.001 to 1 wt%, preferably in the range of 0.02 to 0.75 wt%, and particularly preferably in the range of 0.05 to 0.5 wt%. However, the amount of catalyst can be increased in cases where the polymerization reaction is slow.

[0353] The catalyst is added to the emulsion or dispersion, either in its own form, or, for example, in solid form, or in an aqueous solution, preferably in water, and the mixture is stirred. The concentration of the catalyst in the aqueous solution is from 0.5 to 2 mol / L, preferably 1 mol / L.

[0354] The catalyst is preferably added at a stirring speed of 500 rpm to 2000 rpm, more preferably at a stirring speed of 1000 rpm to 1500 rpm, and preferably at a temperature of 20°C to 30°C, more preferably at a temperature of 22°C to 26°C.

[0355] Even more preferably, the method step (v) of catalyzing the 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°C to 85°C, and most preferably to a temperature in the range of 70°C to 80°C. In the method according to the invention, the first crosslinking is carried out for 30 minutes to 90 minutes, preferably for 40 minutes to 70 minutes, and most preferably for 60 minutes.

[0356] After the first cross-linking and the formation of the capsule shell or capsule wall, the capsules prepared according to the method of the present invention exist as coarse microcapsules in the form of an aqueous dispersion or slurry.

[0357] After crosslinking, the microcapsules in the slurry still retain a flexible shell, which is not particularly stable and therefore easily ruptures. Therefore, the shell is cured. Preferably, the curing in step (vi) is achieved by gradually increasing the temperature of the microcapsule slurry to at least 60°C, preferably in the range of 60°C to 65°C, and up to the boiling point of the microcapsule slurry. Curing typically lasts for at least 3 hours, preferably for 4 hours, and most preferably for 5 hours.

[0358] Another advantage is the addition of a curing (hardening) agent to the microcapsule slurry. The substance is a tannin. For this purpose, natural plant tannins are used, which are chemically proanthocyanidins, particularly found in the leaves of dicotyledonous perennials, shrubs, and plants in tropical and subtropical regions. Terpenes typically have a molecular weight in the range of 500 to 3000 kDa. A preferred example of a suitable tannin is corigallin. For solidification, an aqueous formulation of the tannin is added to an aqueous dispersion containing crude microcapsules. Typically, the amount of tannin added relative to the microcapsules is from about 0.1 to about 2% by weight, preferably from about 0.5 to about 1.5% by weight.

[0359] In another variant of the method according to the invention, in order to optimize the crosslinking of the capsule wall matrix, alternatively, another protein and / or another polysaccharide may be added to the microcapsule slurry in step (vi) of the method.

[0360] The other protein and / or the other polysaccharide is selected from the group of proteins and / or polysaccharides that have been defined in detail in step (ii) of the method above. The same definitions and preferred embodiments and / or preferred combinations as those for proteins and / or polysaccharides also apply to the proteins and / or polysaccharides in the other step.

[0361] The other protein and / or the other polysaccharide may be the same as or different from the protein and / or polysaccharide of method step (ii). Preferably, the other protein and / or the other polysaccharide is different from the protein and / or polysaccharide of method step (ii).

[0362] The addition of another protein and / or another polysaccharide leads to further cross-linking with the first cross-linking agent and helps to build a particularly dense and stable network composed of capsule wall components (building blocks).

[0363] The curing step (vi) of the method according to the invention is followed by a step of cooling the microcapsule slurry to room temperature, and optionally a second crosslinking step is performed on the capsule wall components (building blocks) by adding a second crosslinking agent.

[0364] In the method according to the invention, at least one crosslinking agent is used as a second crosslinking agent for the second crosslinking, said at least one crosslinking agent being selected from the group consisting of: transglutaminase, peroxidase, plant secondary metabolites, and mixtures of two or more of the above crosslinking agents, said plant secondary metabolites being selected from the group consisting of: polyphenols, particularly tannins, gallic acid, ferulic acid, hesperidin, cinnamaldehyde, vanillin, and carvacrol, and mixtures of two or more of the above crosslinking agents, as described above for the first and another crosslinking agent. The same definitions and preferred embodiments as for the first and another crosslinking agent are also fully effective for the second crosslinking agent.

[0365] Among the other crosslinking agents mentioned above, cinnamaldehyde, tannin, and gallic acid are particularly preferred.

[0366] In a preferred variant of the method according to the invention, the second crosslinking agent is different from the first and another crosslinking agent in step (i) of the method.

[0367] The content of the second crosslinking agent is in the range of 0.1% to 5% by weight relative to the total weight of the non-aqueous phase, preferably in the range of 0.15% to 2.5% by weight. Most preferably, the amount of the second crosslinking agent in the internal non-aqueous phase is in the range of 0.5% to 1% by weight relative to the total weight of the non-aqueous phase.

[0368] The second crosslinking agent is added to the emulsion or dispersion either in its own form, such as in solid form, or in the form of an aqueous solution.

[0369] The concentration of the second crosslinking agent in the aqueous solution is from 0.01 to 2 mol / L, preferably from 0.1 to 1.5 mol / L, and most preferably from 0.5 to 1.0 mol / L. The pH of the solution is from 7 to 14, preferably 12.

[0370] More preferably, the second crosslinking in method step (vii) is performed 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°C to 40°C. In the method according to the invention, the second crosslinking is carried out for about 20 minutes to 10 hours, preferably for 30 minutes to 8 hours.

[0371] To optimize the first crosslinking in step (v) and / or the second crosslinking in step (vii) of the method according to the invention, the pH of the emulsion or dispersion may optionally be adjusted to a pH value higher or lower than the isoelectric point of the protein used. When the pH value is lower than the isoelectric point, the net static charge of the protein is positive, and when the pH value is higher than the isoelectric point, the net static charge of the protein is negative.

[0372] Preferably, the pH value is adjusted to a range of pH 2.0 to pH 4.0, more preferably to a range of pH 2.5 to pH 3.5, and most preferably to pH 3.0 to obtain a positive charge on the protein. To obtain a negative charge on the protein, the pH value is preferably adjusted to a range of pH 8.0 to pH 12.0, more preferably to a range of pH 9.0 to pH 10.0, and most preferably to pH 9.5.

[0373] To this end, 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, and the pH value is adjusted within the range described above.

[0374] Performing the first and / or second cross-linking at pH values ​​above or below the isoelectric point has the advantage of altering the protein's charge, thus allowing electrostatic interactions to positively influence capsule formation. Furthermore, this modification of the protein positively affects its emulsifying ability.

[0375] During the first and second crosslinking steps, the stirring power is reduced, for example to a stirring speed of about 800 to 1200 rpm, so as not to immediately pulverize the formed microcapsules again.

[0376] An important criterion for the suitability of microcapsules is the weight ratio of core material to capsule wall material. On the one hand, to maximize the practical value of the capsule, the highest possible core material content is desirable. On the other hand, the capsule must contain a sufficient amount of capsule wall material to ensure its stability.

[0377] According to the invention, it has proven particularly advantageous that the microcapsules are designed to have a weight ratio of core material to capsule wall material of 50:50 to 90:10, preferably 70:30 to 80:20.

[0378] The microcapsules prepared according to the method of the present invention exist in water as a dispersion after complete solidification, which is also referred to as a microcapsule dispersion or microcapsule slurry. This form of microcapsule is essentially commercially available.

[0379] To prevent separation or fragging of the suspension and thus achieve high storage stability, a suspension viscosity of 12 to 1500 mPas has proven advantageous. A thickener is preferably used to obtain the desired viscosity of the suspension.

[0380] The thickener is preferably xanthan gum, diethyl gum, carboxymethyl cellulose (CMC), microcrystalline cellulose (MCC), or guar gum.

[0381] To improve durability, one or more preservatives may be added to the microcapsule slurry, or the microcapsule slurry may be dried.

[0382] Preferably, 1,2-hexanediol, 1,2-octanediol and phenoxyethanol products, mixtures of 1,2-benzisothiazolin-3-one (2.5%) and 2-methyl-4-isothiazolin-3-one (2.5%) or similar products are used as preservatives.

[0383] In addition, for preservation purposes, the microcapsule slurry is preferably dried.

[0384] For drying the microcapsule slurry, processes such as freeze drying can be used, but spray drying in a fluidized bed, for example, is preferred. It has proven advantageous to further add polysaccharides, preferably dextrins, and particularly maltodextrins, to the suspension at a temperature of about 20°C to about 50°C, preferably about 40°C, which supports the drying process and protects the capsules during this process. In this case, the amount of polysaccharide used in the dispersion can be about 50 to about 150% by weight, preferably about 80 to about 120% by weight, relative to the capsule mass.

[0385] Spray drying itself can be carried out continuously or in batches in conventional spray equipment, wherein the inlet temperature is about 170°C to about 200°C, preferably about 180°C to 185°C, and the outlet temperature is about 70°C to about 80°C, preferably about 72°C to 78°C.

[0386] Catalytic cross-linking of polysaccharides and / or proteins with a first cross-linking agent and optionally a second cross-linking agent introduces macromolecules into the network of the capsule shell, which increases the proportion of natural components in the capsule shell or microcapsule syrup, thereby increasing the biodegradability of the capsule shell, as illustrated in the following examples.

[0387] Furthermore, the method according to the invention is characterized by the polymerization and / or cross-linking of proteins, polysaccharides, and polyisocyanates as main components via targeted catalytic mechanisms, thereby enabling the preparation of bio-based and biodegradable microcapsules based on biocompatible polymers. Unlike prior art microcapsules where polyisocyanates constitute a large proportion of the capsule shell material, the situation here is entirely reversed. In the microcapsules according to the invention, polyisocyanates are no longer the main material, but rather serve only as cross-linking agents for amino acids and the other aforementioned components.

[0388] Therefore, the method according to the invention allows for the replacement of a portion of the polyisocyanate with biodegradable wall materials such as protective colloids, proteins, and / or polysaccharides, thereby reducing the proportion of polyisocyanates without causing any loss or impairment of microcapsule functionality, such as olfactory properties and positive secondary properties such as high stability, i.e., the ability to retain active substances. Thus, the method according to the invention can prepare microcapsules that possess both outstanding functionality and are readily biodegradable.

[0389] Surprisingly, it has been found that the method according to the invention can be used to prepare microcapsules in which the amount of isocyanate, the starting material for the microcapsules, is reduced by 25%, preferably by 50%, even more preferably by 75%, or by other prior art microcapsule starting materials, while maintaining the same amount of active material to be encapsulated, and the stability of the resulting microcapsules is not lost or compromised, as shown in the following examples.

[0390] In a second aspect, the present invention relates to microcapsules or microcapsule slurries prepared according to the method of the present invention.

[0391] Biodegradable protein / polysaccharide microcapsules are characterized by comprising or containing the following:

[0392] (a) A core, which contains or is composed of at least one hydrophobic active substance;

[0393] (b) A capsule shell comprising or consisting of: a cross-linking matrix or cross-linking unit composed of at least one polysaccharide and / or at least one protein and at least one first cross-linking agent; and optionally a protective colloid and / or optionally a second cross-linking agent.

[0394] The microcapsules according to the invention comprise a core, which is encapsulated or wrapped by a capsule shell or capsule wall. The core material used to prepare the microcapsules according to the invention can be any material suitable for encapsulation within the microcapsule. The material to be encapsulated is preferably a lipophilic, water-insoluble or water-immiscible liquid or solid, or a suspension.

[0395] In the context of this specification, the core material is a hydrophobic active substance, that is, a substance that has a specific effect or causes a specific reaction, such as pharmaceuticals, plant protectants, cosmetic active substances, food active substances, etc., as described above. The term "hydrophobic active substance" refers to an active substance to be encapsulated in a non-aqueous internal phase during the preparation of microcapsules, which does not mix with the external aqueous phase.

[0396] The polymerization and / or crosslinking of functional groups of proteins and / or polysaccharides with polyisocyanates results in a stable capsule wall composed of alternating and dense and therefore stable crosslinking matrices or crosslinking units based on polyurea and polyurethane as well as soluble or insoluble complexes of proteins and polysaccharides.

[0397] In a preferred embodiment, the capsule shell comprises or consists of: a cross-linked matrix or cross-linked unit formed by polymerization and / or cross-linking of at least one protein with a first cross-linking agent and optionally a second cross-linking agent, and / or a cross-linked matrix or cross-linked unit formed by polymerization and / or cross-linking of at least one polysaccharide with a first cross-linking agent and optionally a second cross-linking agent.

[0398] The cross-linked matrix or cross-linked unit formed by the polymerization and / or cross-linking of at least one protein with a first and optional second cross-linking agent is mainly a polyurea network; the cross-linked matrix or cross-linked unit formed by the polymerization and / or cross-linking of at least one polysaccharide with a first and optional second cross-linking agent is mainly a polyurea network; and soluble or insoluble complexes of proteins and polysaccharides.

[0399] In addition to the formation of polyurethane through the formation of polyurea described above, byproducts are generated during the crosslinking steps due to the reactivity of polyisocyanates. These byproducts include urea, urethane, biuret, urea diketone, carbodiimide, and urea ketimide, as described in M.F. Sonnenschein, Introduction to Polyurethane Chemistry, Polyurethanes: Science, Technology, Markets, and Trends, First Ediiton, 2015, John Wiley & Sons, pp. 105-126, the entire disclosure of which is incorporated herein by reference. These byproducts are components of the capsule shell or capsule wall.

[0400] By constructing capsule walls based on multiple separate, defined, and alternating crosslinking matrices or crosslinking units, it is possible to prepare particularly stable microcapsules with excellent sensory properties, while significantly reducing the shell component.

[0401] In addition to the main components listed above, the capsule shell may also contain a protective colloid and / or an optional crosslinking agent.

[0402] In a preferred variant according to the second aspect, the microcapsules according to the invention are present 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% by weight, particularly about 25 to 50% by weight, more preferably about 30 to 35% by weight.

[0403] Microcapsules prepared by the method of the present 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.

[0404] To determine the particle size distribution, microcapsules containing different components according to the present invention were dispersed in water within a dynamic process, and the particle size was then determined by laser diffraction. The refraction of the laser beam varies depending on the size of the capsule, and can therefore be converted into size. The Mie theory is used for this. Particle measurements were performed using a MALVERN Mastersizer 3000. The corresponding calculations are based on the Mie theory.

[0405] The microcapsules according to the invention are characterized in that their particle size distribution is in the range of d(0.5) value from 18 micrometers to 50 micrometers, preferably in the range of d(0.5) value from 22 micrometers to 30 micrometers.

[0406] Figures 1a to 1d The corresponding particle size distribution of the microcapsules according to the present invention is described as follows:

[0407] Figure 1aSymcap B: 20% isocyanate content; whey protein / pectin and maltodextrin; microcapsules according to the invention;

[0408] Figure 1b Symcap B: 20% isocyanate content; milk protein and maltodextrin, with added cross-linking agent tannin; microcapsules according to the present invention;

[0409] Figure 1c Symcap B: 30% isocyanate content; milk protein / L-glutamine, L-lysine and maltodextrin; microcapsules according to the present invention;

[0410] Figure 1d Symcap B: 20% isocyanate content; gelatin and maltodextrin; microcapsules according to the invention;

[0411] Figure 1e Particle size distribution comparison: Existing microcapsules, Symcap G 2.1: 100% isocyanate, polyvinyl alcohol and guanidine carbonate; Microcapsules according to the present invention, Symcap B: 20% isocyanate, milk protein, tannin.

[0412] Direct comparison of microcapsules shows that the method according to the invention can obtain the same particle size distribution as microcapsules in the prior art.

[0413] Surprisingly, the protein and / or polysaccharide-based microcapsules prepared according to the method of the present invention, despite a reduction in the polyisocyanate content in the microcapsule wall, still exhibit stability comparable to prior art microcapsules and an undesirable amount of aromatic oil leakage, such as... Figure 2 and Figure 3 As shown. The microcapsules prepared according to the present invention using an additional second crosslinking agent have comparable, or even better, stability compared to prior art microcapsules, resulting in a lower content of free oil, such as Figure 2 and Figure 3 As shown. This can be specifically attributed to the more effective encapsulation of the fragrance.

[0414] In particular, the use of a different crosslinking agent (especially when the isocyanate content is reduced) leads to a significant improvement in stability, thereby reducing the amount of aromatic oils spilled out (see...). Figure 2 and 3 Samples 7 and 8, and samples 3 and 4, 5 and 6.

[0415] In applications targeting microcapsules, particularly those prepared using a different crosslinking agent, despite the reduced polyisocyanate content, comparable stability values ​​were observed compared to prior art microcapsules (see [link to relevant documentation]). Figure 5 ).

[0416] Furthermore, compared to capsules of the prior art, the protein and / or polysaccharide-based microcapsules according to the present invention also show significant improvements in sensory properties (flavor release), which can be attributed to stable encapsulation of active substances and the resulting loss of low-activity substances. Figure 6 As shown, when the capsule is opened by mechanical friction or pressure to release the aroma, the microcapsules according to the present invention exhibit a significant sensory intensity.

[0417] The degree of cross-linking is related to the cross-linking agent and its concentration. As the degree of cross-linking increases, the stability of the microcapsules increases, but at the same time, the biodegradability of the capsule shell decreases. Figure 7 Overall, the correlation between the stability, performance, and biodegradability of microcapsules and the degree of cross-linking is shown. For example, very stable microcapsules exhibit lower performance (such as sensory properties) because the number of microcapsules that break down and release the active substance due to factors such as friction and pressure is reduced. If the microcapsules are very unstable, they are already destroyed during use or storage, thus failing to exhibit any performance.

[0418] As illustrated in the following examples, the protein and / or polysaccharide-based microcapsules according to the present invention reduce the polyisocyanate content by up to 75% compared to prior art polyurea / polyurethane microcapsules, without any loss or deficiency in stability or the amount of active material to be encapsulated in the microcapsules. Compared to prior art microcapsules, isocyanate is no longer used as the primary material, but only as a crosslinking agent for the proteins and / or polysaccharides in the capsule shell. Therefore, the absolute polyisocyanate content of the microcapsules described herein is only equivalent to 1.5% of the entire microcapsule.

[0419] On the one hand, due to the low polyisocyanate content in the capsule shell or capsule wall, and on the other hand, due to the use of proteins and / or as components of the capsule wall, the microcapsules according to the present invention are more easily biodegradable than capsules of the prior art. As shown in the following examples, the microcapsules according to the present invention have significantly better biodegradability.

[0420] Biodegradability is the ability of organic matter to be degraded into water, carbon dioxide (CO2), and biomass under specified temperature, oxygen, and humidity conditions, in the presence of microorganisms or fungi, over a specified period of time.

[0421] According to OECD 301F, microcapsules are considered immediately biodegradable if more than 60% of the wall material is degraded after 28 days.

[0422] The microcapsules of the present invention have a biodegradability of ≥10% according to OECD 301F after 28 days, preferably ≥50%, even more preferably ≥70%, and most preferably ≥90%.

[0423] The combination of starting components enables the microcapsules according to the invention to possess sufficient stability (mechanical and diffusion stability in use) and high sensory properties, while also exhibiting good biodegradability. Simultaneously, the composition of the starting components keeps the degree of cross-linking at a low level, which significantly improves the biodegradability of the microcapsules. Therefore, previously valid correlations between sensory properties, high cross-linking, and biodegradability may be disrupted.

[0424] Due to the biodegradability, excellent stability, and outstanding release capacity of microcapsules, as well as the possibility of encapsulating a wide range of hydrophobic active ingredients with microcapsules according to the invention, protein- and polysaccharide-based microcapsules according to the invention can be widely used in the application of fragrances and flavorings.

[0425] Furthermore, the microcapsules of the present invention are universal capsules that, as they are currently available, can be used to encapsulate a wide range of flavorings or seasonings, even those with aldehyde, carboxylic acid, or ester functions, and therefore there are no limitations on individual active substances.

[0426] Due to their advantageous properties, particularly their stability and directed release of active substances and their biodegradability, the microcapsules according to the present invention are suitable for a wide range of applications, especially for household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance enhancers, fragrance washes and aroma enhancers, cosmetics, personal care products, agricultural products, pharmaceutical products or paper printing coatings, etc.

[0427] Therefore, 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 manufacture of household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance enhancers, fragrance washes or aroma in liquid or solid forms, cosmetics, personal care products, agricultural products, pharmaceutical products, or paper printing coatings, etc. The microcapsules according to the invention are particularly suitable for incorporation with hydrophobic fragrances or flavorings that can be used in a variety of household and textile care products.

[0428] Finally, the present invention relates to household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance enhancers, fragrance washes or aroma enhancers, cosmetics, personal care products, agricultural products, pharmaceutical products, paper printing coatings, etc., containing biodegradable protein and / or polysaccharide microcapsules according to the present invention or dispersions of protein and / or polysaccharide microcapsules according to the present invention.

[0429] In the above-mentioned products, the proportion of microcapsules relative to the total weight of the products is 0.05 to 15% by weight, preferably 0.2 to 5% by weight.

[0430] Example

[0431] The biodegradable protein or / or polysaccharide-based microcapsules according to the present invention and their beneficial properties will be described in more detail by way of the following examples.

[0432] Example 1: Microcapsules according to the present invention and those according to the prior art G2.1 and Comparison of free oil content in G3 microcapsules

[0433] The following stability data refers to tests conducted at 40°C using commercially available formulations, such as fragrance enhancers or fabric softeners.

[0434] In the examples below, microcapsules whose walls consist solely of a polyurea network are selected as prior art capsules. A mixture of hexamethylene diisocyanate and 4,4'-4,4'-diphenylmethane diisocyanate in an 80:20 ratio is used as the polyisocyanate. Polyvinyl alcohol is used as the protective colloid, and guanidine carbonate is used for crosslinking. Typically, no catalyst is used in the preparation of these capsules, and synthesis is carried out at pH 9.

[0435] Microcapsules according to the invention were prepared using two different proteins. One was gelatin, and the other was milk protein further incorporating the amino acids glutamine L and lysine L. The polysaccharide used in both cases was maltodextrin DE 8-10. A mixture of hexamethylene diisocyanate and 4,4'-4,4'-diphenylmethane diisocyanate in an 80:20 ratio was used as the polyisocyanate. DABCO was used as the catalyst. Cinnamaldehyde was used as another cross-linking agent.

[0436] The fragrance oil content in all samples was 35% of the obtained microcapsule slurry, wherein the fragrance oil and vegetable oil were mixed in a 1:1 ratio.

[0437] The free oil content in isopropanol was measured by mixing a specified amount of microcapsule slurry with isopropanol, stirring for 30 seconds, and then sampling. The sample was measured using GC-MS. The results indicate how much of the encapsulated oil entered the isopropanol or was not completely encapsulated. Therefore, the free oil content can indicate the effectiveness of the method itself, i.e., whether the aromatic oil was completely encapsulated, and / or whether the capsule shell was sufficiently stable to prevent the aromatic oil from precipitating out of the isopropanol. A value less than 1% was considered an indicator of successful encapsulation and a stable capsule shell.

[0438] The free oil content of the microcapsules according to the present invention is different from that of microcapsules according to the prior art. G2.1 (100%) and The free oil content of G3 (75%) was compared.

[0439] Microcapsules based on existing technology:

[0440] Sample 1: G2.1: Isocyanate content 100%; crosslinked with polyvinyl alcohol and guanidine carbonate.

[0441] Sample 2: G3: Isocyanate content 75%; crosslinked with polyvinyl alcohol and guanidine carbonate.

[0442] The microcapsules according to the present invention:

[0443] Sample 3: Symcap B: 50% isocyanate content; gelatin and maltodextrin;

[0444] Sample 4: Symcap B: 50% isocyanate content; gelatin and maltodextrin; with added cross-linking agent gallic acid;

[0445] Sample 5: Symcap B: 30% isocyanate content; gelatin and maltodextrin;

[0446] Sample 6: Symcap B: 30% isocyanate content; gelatin and maltodextrin; with added cross-linking agent cinnamaldehyde;

[0447] Sample 7: Symcap B: 50% isocyanate content; milk protein + L-glutamine + L-lysine and maltodextrin;

[0448] Sample 8: Symcap B: 50% isocyanate content; milk protein + L-glutamine + L-lysine and maltodextrin; with added cross-linking agent cinnamaldehyde;

[0449] Sample 9: Symcap B: Isocyanate content 30%; Milk protein + L-glutamine + L-lysine and maltodextrin;

[0450] Sample 10: Symcap B: 30% isocyanate content; milk protein + L-glutamine + L-lysine and maltodextrin; with added cross-linking agent cinnamaldehyde;

[0451] After achieving good results with an isocyanate content of 50%, the isocyanate content was further reduced, and a second cross-linking method was used to achieve results comparable to those of microcapsules according to the prior art.

[0452] Table 1:

[0453]

[0454]

[0455] The results are as follows Figure 2 and Figure 3 As shown.

[0456] The results above show that, compared with microcapsules of the prior art, the microcapsules of the present invention, containing less isocyanate, have almost the same free oil content. Crosslinking with another crosslinking agent can further improve the stability of the microcapsule wall and further reduce the free oil content.

[0457] According to the present invention, the free oil content of all three microcapsule samples was less than 1%, which is an indicator of successful encapsulation and stable capsule shell.

[0458] Example 2: Free oil content of the microcapsules according to the present invention with and without an additional cross-linking agent (transglutamate (TG)).

[0459] Microcapsules were prepared using three different proteins. First, gelatin; second, milk protein; and third, milk protein with the added amino acids L-glutamine and L-lysine. The polysaccharide used in both cases was maltodextrin DE 8-10. DABCO was used as a catalyst. Microcapsule samples were prepared with and without a different cross-linking agent; transglutaminase (TG) was used as another cross-linking agent.

[0460] The free oil content was determined as described in Example 1.

[0461] The results are as follows Figure 4 As shown.

[0462] Example 3: Stability of microcapsules in use

[0463] The stability of the microcapsules according to the invention and microcapsules prepared according to the prior art, as described above or similarly, was measured in the target application. The stability test was conducted using a representative softener (fabric softener), to which 1% by weight of the microcapsule slurry was added, and stored at room temperature and 40°C, respectively. Samples were taken and their stability measured after specified time intervals (24 hours and 1 week).

[0464] Microcapsules based on existing technology:

[0465] Sample 1: G2.1: Isocyanate content: 100%;

[0466] Sample 2: G3: Isocyanate content: 75%;

[0467] The microcapsules according to the present invention:

[0468] Sample 3: Symcap B: Isocyanate content: 50%, pea protein, dextrin

[0469] Sample 4: Symcap B: 50% isocyanate content; gelatin and maltodextrin

[0470] Sample 5: Symcap B: 50% isocyanate content; milk protein, amino acids, cross-linking agent transglutaminase, maltodextrin. Sample 6: Symcap B: 30% isocyanate content; gelatin, maltodextrin.

[0471] Sample 7: Symcap B: Isocyanate content 30%; Gelatin, cross-linking agent tannin, maltodextrin

[0472] Measurements: Capsule contents were analyzed using Headspace-GC / MS (SPME fiber: PDMS-DVB 65μm-Mantel).

[0473] analyze:

[0474] Integrate the area of ​​each aromatic oil compound and calculate the stability interval.

[0475] ΣGC area of ​​all encapsulated components in the sample × 100%

[0476] Capsule stability = 100%

[0477] ΣGC area of ​​all flavor components in the quantification standard

[0478] The identification of flavor components is based on internal databases and commercial flavor formulation analysis databases.

[0479] This allows us to determine the percentage of flavoring oil remaining in the capsule. For example, a result of 98% means that the capsule no longer contains the original 2% flavoring oil.

[0480] The results show Figure 5 middle.

[0481] from Figure 5 As can be seen, despite reducing the polyisocyanate content, the use of additional crosslinking agents exhibits equivalent stability values ​​in applications.

[0482] Example 4: Sensory evaluation of the microcapsules according to the present invention

[0483] For sensory evaluation, the microcapsules of the present invention are compared with prior art microcapsules, namely microcapsules prepared as described above:

[0484] Microcapsules based on existing technology:

[0485] Sample 1: G2.1: Isocyanate content: 100%;

[0486] The microcapsules according to the present invention:

[0487] Sample 2: Symcap B: 30% isocyanate content; gelatin and maltodextrin; added cross-linking agent tannin;

[0488] Sample 3: Symcap B: 20% isocyanate content; milk protein and maltodextrin; added cross-linking agent tannin;

[0489] Aromatic oil: Tomcap

[0490] Sensory evaluation was conducted as follows: the microcapsules were added to fabric softener at a concentration of 0.4% by weight (fragrance Tomcap), and then washed. A control was prepared by adding 0.07% pure fragrance oil to the fabric softener, with capsules containing 17.5% aromatic oil (+17.5% vegetable oil = 35% total load) and 0.4% of the capsule paste. 30 grams of fabric softener were used for 2 kg of laundry, including cotton towels. Washing instructions were as follows: laundry, including cotton towels, was placed in the washing machine, and fabric softener was added to the fabric softener compartment. The washing program "Express 20; 900 rpm" was started. The cotton towels were then air-dried overnight at room temperature.

[0491] Sixteen subjects participated in a paired comparison test, using a rating scale from 1 (no odor) to 9 (very strong odor) to assess the fragrance intensity of cotton towels after washing, with the control fabric softener containing the corresponding amount of free aromatic oil.

[0492] Fragrance rating was conducted in three steps. The first step described the odor of the untreated fabric. The second step described the odor of the fabric after it had been lightly crumpled; this was done by moving the fabric back and forth between the hands several times, applying slight mechanical pressure to the fabric and causing the capsule to break. The third step described the odor of the fabric after it had been subjected to strong friction, causing the capsule to break. The fragrance intensity was assessed after each step.

[0493] The results of the sensory evaluation are shown in Table 6.

[0494] In fact, the microcapsules according to the invention have the same, or even stronger, odor as microcapsules according to the prior art. In particular, further use of another crosslinking agent produces even better sensory properties.

[0495] The advantage here lies in the stability of the microcapsules according to the invention. Although the isocyanate content is reduced to 30% relative to the capsule shell, it still exhibits considerable stability.

[0496] Due to the aforementioned advantageous properties, compared to prior art microcapsules, the microcapsules according to the present invention are expected to maintain consistent quality over a long period, and therefore also possess sensory stability. Furthermore, the biodegradability of prior art microcapsules is inferior to that of the microcapsules according to the present invention.

[0497] Example 5: Biodegradability of the microcapsules according to the present invention

[0498] According to OECD 301F, biodegradability is determined as follows: the degradability of the wall material in a non-pre-adapted culture medium is measured by pressure respiration (oxygen consumption).

[0499] Table 2:

[0500]

[0501] As the amount of isocyanate (crosslinking agent) used decreases, biodegradability increases.

Claims

1. A method for preparing biodegradable polysaccharide-based microcapsules, the method comprising the following steps in sequence: (i) Providing an internal non-aqueous phase comprising at least one first crosslinking agent and at least one hydrophobic active substance, and optionally at least one other crosslinking agent; (ii) Providing an external aqueous phase comprising at least one polysaccharide and optionally at least one protective colloid; (iii) Emulsifying or dispersing the internal non-aqueous phase in the external aqueous phase, optionally in the presence of at least one stabilizer and / or at least one emulsifier, to obtain an oil-in-water emulsion or dispersion; (iv) Optionally, at least one other polysaccharide may be added; (v) A first cross-linking process is performed by adding at least one catalyst to obtain a microcapsule slurry; (vi) The microcapsule slurry is cured at a temperature of at least 60°C, and optionally another polysaccharide is added; (vii) Cooling and second crosslinking by adding at least one second crosslinking agent; as well as (viii) Optionally, the microcapsules are separated from the microcapsule slurry, and the microcapsules are optionally dried or the viscosity of the microcapsule slurry is adjusted by adding at least one thickener. The at least one first crosslinking agent is selected from the group consisting of: polyisocyanates having two or more isocyanate groups and mixtures of the two or more first crosslinking agents described above, wherein the polyisocyanate groups are selected from the group consisting of: aliphatic, alicyclic, hydrogenated aromatic, aromatic or heterocyclic polyisocyanates, their substituted products, and mixtures of the above compounds; The at least one or at least one second cross-linking agent is selected from the group consisting of transglutaminase, peroxidase, plant secondary metabolites, and mixtures of two or more of the above cross-linking agents, wherein the plant secondary metabolites are selected from the group consisting of polyphenols.

2. The method according to claim 1, wherein the polyisocyanate comprises two aliphatic polyisocyanates or one aliphatic and one aromatic polyisocyanate.

3. The method according to claim 1, wherein the polyisocyanate comprises polyisocyanates with alternating monomer, oligomeric, or polymeric structures having different chain lengths.

4. The method according to claim 1, wherein the plant secondary metabolite is selected from the group consisting of: tannins, gallic acid, ferulic acid, hesperidin, cinnamaldehyde, vanillin, and carvacrol.

5. The method according to any one of claims 1 to 4, wherein the at least one hydrophobic active substance is selected from the group consisting of: fragrances, flavorings, cooling agents, TRPV1 and TRPV3 modifiers, substances that cause an irritating taste or heat or hot sensation on the skin or mucous membranes, or substances that cause a tingling or numbing sensation in the mouth or throat, or active substances having irritating, spicy or astringent effects, pesticides, biocides, insecticides, insect repellents, food additives, cosmetic active substances, pharmaceutical active substances, agrochemicals, dyes, colorants, dye precursors, fluorescent dyes, optical brighteners, solvents, waxes, silicone oils, lubricants, paper printing coatings, and mixtures of two or more of the above active substances.

6. The method according to any one of claims 1 to 4, wherein the at least one polysaccharide or the at least another polysaccharide is selected from the group consisting of: - Indigestible fiber and dietary fiber; - Starch; and starch derivatives; and - Sugar alcohols; - Cold gelatin; glucose, And a mixture of the above polysaccharides.

7. The method according to claim 6, wherein the dietary fiber is selected from the group consisting of insoluble dietary fiber and soluble dietary fiber.

8. The method according to claim 7, wherein the insoluble dietary fiber is selected from the group consisting of: cellulose, cellulose derivatives, hemicellulose, lichen polysaccharides, chitin, chitosan, lignin, xanthan gum, and plant fibers.

9. The method according to claim 8, wherein the plant fiber is selected from the group consisting of: cereal fiber, potato fiber, apple fiber, citrus fiber, bamboo fiber, extracted beet fiber, and oat fiber.

10. The method of claim 8, wherein the cellulose derivative is selected from the group consisting of hydroxyethyl cellulose, carboxymethyl cellulose, and microcrystalline cellulose.

11. The method of claim 10, wherein the hydroxyethyl cellulose is quaternized hydroxyethyl cellulose.

12. The method according to claim 7, wherein the soluble dietary fiber is selected from the group consisting of: inulin, pectin, alginate, agar, carrageenan, gum arabic, konjac gum, guar gum, carob gum, xanthan gum, raffinose, xylose, polydextrose, and lactulose.

13. The method of claim 12, wherein the inulin is selected from the group consisting of: natural inulin, highly soluble inulin, particulate inulin, and high-performance inulin.

14. The method of claim 6, wherein the starch is selected from the group consisting of starches derived from wheat, potato, corn, rice, cassava, and oats, as well as chemically, mechanically, and / or enzymatically modified starches.

15. The method of claim 6, wherein the starch derivative is selected from the group consisting of dextrin and oligosaccharides.

16. The method of claim 15, wherein the dextrin is selected from the group consisting of: dextrin derived from wheat, potato, corn, rice and oats.

17. The method of claim 15, wherein the paste is selected from the group consisting of maltodextrin and cyclodextrin.

18. The method of claim 17, wherein the maltodextrin is selected from the group consisting of maltodextrin derived from wheat, potatoes, corn, rice, and oats.

19. The method of claim 17, wherein the maltodextrin is selected from the group consisting of: maltodextrin DE8-10, DE17-20 and DE18-20.

20. The method of claim 15, wherein the oligosaccharide is fructooligosaccharide.

21. The method of claim 6, wherein the sugar alcohol is selected from the group consisting of sorbitol, mannitol, isomaltitol, maltitol, maltitol syrup, lactitol, xylitol, and erythritol.

22. The method according to any one of claims 1 to 4, wherein the at least one protective colloid is selected from the group consisting of: -Polyols, - Polyvinylpyrrolidone, vinyl maleate copolymer, sodium lignosulfonate, maleic anhydride / styrene copolymer, ethylene / maleic anhydride copolymer, copolymer of ethylene oxide, propylene oxide and polyethoxylated sorbitol, sodium dodecyl sulfate -Animal and plant polymers, And mixtures of the above compounds; and / or the protective colloid used in combination with starch.

23. The method of claim 22, wherein the polyol is selected from the group consisting of: diols, triols, polyvinyl alcohol and its derivatives, polyphenols and polysaccharides.

24. The method of claim 23, wherein the diol is selected from the group consisting of: ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, isomer of butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, and 1,2-dodecanediol.

25. The method of claim 23, wherein the triol is selected from the group consisting of glycerol and its ethoxylated and propoxylated products, and trimethylolpropane and its ethoxylated and propoxylated products.

26. The method of claim 23, wherein the polyvinyl alcohol derivative is selected from the group consisting of ammonium or sulfonate-functionalized polyvinyl alcohol.

27. The method of claim 23, wherein the polyphenol is selected from the group consisting of 1,3,5-trihydroxybenzene.

28. The method of claim 23, wherein the polysaccharide is selected from the group consisting of glucose, starch, chemically, mechanically and / or enzymatically modified starch, and cellulose derivatives.

29. The method of claim 28, wherein the cellulose derivative is selected from the group consisting of hydroxyethyl cellulose and carboxymethyl cellulose.

30. The method of claim 29, wherein the hydroxyethyl cellulose is quaternized hydroxyethyl cellulose.

31. The method of claim 22, wherein the animal and plant polymers are selected from the group consisting of gum arabic, proteins, gelatin, mastic resin, shellac, lignin, chitosan, and saponins.

32. The method according to any one of claims 1 to 4, wherein the at least one catalyst is selected from the group consisting of: diazabicyclo[2.2.2]octane, bismuth catalyst, tin catalyst, and mixtures of two or more of the above catalysts.

33. The method according to any one of claims 1 to 4, wherein the first crosslinking is carried out at a temperature of 60°C to 90°C.

34. The method according to any one of claims 1 to 4, wherein the microcapsule curing is carried out at a temperature of 60°C to 90°C and / or for a duration of at least 3 hours.

35. A biodegradable microcapsule or microcapsule slurry, said microcapsule or microcapsule slurry being obtained by the method according to any one of claims 1 to 34.

36. A biodegradable microcapsule obtained by the method according to any one of claims 1 to 34, comprising or consisting of: (a) A core, which contains or consists of at least one hydrophobic active substance; (b) A capsule shell comprising or consisting of: a crosslinking matrix or crosslinking unit of at least one polysaccharide and at least one first crosslinking agent; and optionally at least one protective colloid and / or at least one other crosslinking agent, wherein the first crosslinking agent is selected from the group consisting of: polyisocyanates having two or more isocyanate groups, wherein the polyisocyanate groups are selected from the group consisting of: aliphatic, alicyclic, hydrogenated aromatic, aromatic or heterocyclic polyisocyanates, their substituted products, and mixtures thereof; wherein the at least one other crosslinking agent is selected from the group consisting of: transglutaminase, peroxidase, plant secondary metabolites, and mixtures thereof of two or more crosslinking agents, wherein the plant secondary metabolites are selected from the group consisting of: polyphenols.

37. The biodegradable microcapsule of claim 36, wherein the plant secondary metabolite is selected from the group consisting of tannins, gallic acid, ferulic acid, hesperidin, cinnamaldehyde, vanillin, and carvacrol.

38. The biodegradable microcapsule of claim 36, wherein the at least one polyisocyanate comprises two aliphatic polyisocyanates or one aliphatic and one aromatic polyisocyanate.

39. The biodegradable microcapsule of claim 36, wherein the at least one polyisocyanate comprises polyisocyanates with alternating monomeric, oligomeric, or polymeric structures having different chain lengths.

40. The biodegradable microcapsule of claim 36, wherein the capsule shell comprises or is composed of: A crosslinked matrix or crosslinked unit is generated by polymerization and / or crosslinking of at least one polysaccharide with the first crosslinking agent and another crosslinking agent.

41. A microcapsule slurry comprising microcapsules according to any one of claims 35 to 40, optionally in combination with a thickener and / or a preservative.

42. Use of the microcapsules according to any one of claims 35 to 40 or the microcapsule slurry according to claim 35 or claim 41 in the manufacture of household goods, textile care products, detergents, fabric softeners, cleaning agents, fragrance enhancers or aroma enhancers in liquid or solid form, cosmetics, personal care products, fragrance compositions, agricultural products, pharmaceutical products or paper printing coatings.

43. Household products, textile care products, detergents, fabric softeners, cleaning agents, fragrance enhancers and aroma enhancers, cosmetics, personal care products, fragrance compositions, agricultural products or pharmaceutical products containing microcapsules according to any one of claims 35 to 40 or microcapsule pastes according to claim 35 or 41.

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