Microcapsules, process for preparation of microcapsules and use of microcapsules for perfuming consumer products

Abstract

The present invention relates to the field of perfuming particles, in particular for use in solid consumer product formulations such as textile care products and the like. More specifically, the present invention relates to microcapsules and methods of making microcapsules. Furthermore, the invention relates to microcapsules obtained by this process. The invention also relates to consumer products comprising at least one microcapsule according to the invention, and to the use of microcapsules for perfuming consumer products according to the invention.

Description

Technical Field

[0001] The present invention relates to the field of perfumed granules, in particular to the field of perfumed granules for solid consumer product formulations such as textile care products and the like. More specifically, the present invention relates to microcapsules and methods for preparing microcapsules. In addition, the present invention relates to microcapsules obtained by the method. The present invention also relates to consumer products comprising at least one microcapsule according to the present invention, and to the use of the microcapsules for perfuming consumer products according to the present invention. Background Art

[0002] Currently, many consumer products such as detergents, fabric softeners, washing powders, deodorants, lotions, etc. are perfumed with fragrance materials or contain cosmetic ingredients to deliver specific effects.

[0003] WO 2008 / 098 387A1 discloses microcapsules comprising a fragrance core and an aminoplast polymer shell, wherein the shell comprises a thermosetting resin, a terpolymer and a polymerization stabilizer. The terpolymer also comprises a moiety derived from at least one polyamine, a moiety derived from at least one aromatic polyol and a moiety having methylene units.

[0004] EP 3 099 404 B1 discloses single-shell aminoplast core-shell microcapsules crosslinked with polyisocyanate and encapsulating a perfume oil, and provides the use of the microcapsules in liquid aqueous and powder surfactant-rich consumer products.

[0005] WO 2020 / 114 975A1 describes microcapsules comprising a core containing at least one active ingredient and a capsule wall, the capsule wall consisting of at least three polymer layers, and at least one of the polymer layers consisting of a first phenolic resin comprising groups derived from at least one aromatic polyol, and at least another of the polymer layers consisting of a second phenolic resin comprising groups derived from at least one triphenol.

[0006] WO 2016 / 028 875A1 discloses a method for preparing a capsule delivery system having two or more different capsules. Also disclosed are capsule delivery systems and consumer products containing such capsule delivery systems.

[0007] US2014 322 283A1 discloses water-dispersible core-shell microcapsules substantially free of formaldehyde. In particular, the present invention relates to core-shell microcapsules having a shell obtained by reacting a polyisocyanate or a polyethylene oxide crosslinking agent with an oligomeric composition which is the reaction product between a polyamine component and a specific mixture of glyoxal and 2,2-dialkoxy-acetaldehyde.

[0008] US2014 / 378 367A1 discloses single-shell aminoplast core-shell microcapsules stabilized by polyisocyanates and further describes methods for stabilizing aminoplast microcapsules in surfactant-rich liquid aqueous consumer products.

[0009] US2016 354 749A1 describes a method for preparing organic-inorganic microcapsules having a flavor or fragrance core and a hybrid shell composed of at least two types of crosslinked inorganic particles.

[0010] WO 2012 / 107 323A1 relates to polyurea core-shell microcapsules having a polyurea shell, which comprise the reaction product of a polyisocyanate with guazoles and amino acids.

[0011] US 9 271 905 B2 discloses a method for producing fragrance-containing microcapsules having a polyurea wall, which can be used in household or personal care products, as well as the microcapsules themselves and consumer products containing these microcapsules. The method of the present invention uses a combination of specific relative concentrations of aromatic and aliphatic polyisocyanates.

[0012] Unfortunately, generally, for example, the fragrance substances or cosmetic ingredients of such products interact with other components of the product formulation, or the volatile components of the fragrance formulation tend to evaporate prematurely. As a result, this leads to undesired changes and / or reduction of the fragrance impression and / or premature "use" of the cosmetic ingredients over time or may even cause adverse reactions with other ingredients of the product formulation, resulting in reduced product quality and / or stability. To prevent possible interactions between the fragrance or other active components and other ingredients of the product, or for example to prevent the volatilization of the fragrance and thus not distort or reduce the desired olfactory impression, the fragrance or other active ingredients can be added to the formulation in encapsulated form. In this way, for example, the desired olfactory impression can be ensured based on the targeted release of the active components. In addition, the interaction between product components can be reduced, thus allowing for improved product quality and storage stability.

[0013] Thus, a variety of consumer products include encapsulated active ingredients, such as fragrances, in their formulations. For example, textile care formulations such as liquid detergents or fabric softeners include a plurality of such perfumed microcapsules. However, incorporating microcapsules into powder formulations significantly exacerbates the problem, as the mixing of microcapsule components and other detergent components results in the rupture of fragile microcapsules, causing, for example, a loss of olfactory performance. It is particularly difficult to prepare microcapsules that simultaneously have good stability and good release properties. The ability of the capsules to retain the active ingredient and thus prevent the loss of volatile components particularly depends on the stability of the capsules in the product matrix. However, very stable microcapsules, such as capsules with a rather thick capsule wall, generally tend to exhibit low performance, as the rupture of the microcapsules and thus the release of the active ingredient are hindered. However, if they are too unstable, they are already destroyed during storage or cause leakage of the active ingredient and are also ineffective. Thus, an increase in the capsule wall, i.e., a multi-layer microcapsule shell or a thicker shell respectively, also results in a reduction in performance, as the targeted release of the active ingredient is deteriorated and the microcapsules generally require complex multi-step preparation methods.

[0014] Furthermore, considering the increasing ecological awareness of the public (less waste, fewer preservatives, etc.), there is a new and increasing trend towards solid consumer products such as solid hair care products, soaps and solid bath agents, such that solid consumer products will become increasingly relevant not only in the cosmetics industry but also in other industries.

[0015] Therefore, there is a need to improve the effective incorporation of active substances, such as perfuming ingredients, into solid consumer product formulations, which simultaneously allows for the effective and targeted release of said active substances.

[0016] In particular, there is a need to provide the formulations comprising said active substances, wherein the active substances are provided with improved stability and improved release characteristics. Summary of the Invention

[0017] The present invention has been made in view of the above disadvantages. To solve the above disadvantages, the present invention provides microcapsules and a method for their preparation, which allow for the effective incorporation of active ingredients with improved stability into solid consumer product formulations for the preparation of consumer products that further provide improved release characteristics.

[0018] Thus, in a first aspect, the present invention relates to microcapsules comprising at least one ingredient, preferably comprising at least one fragrance, and at least three different layers surrounding said ingredient, wherein at least one layer is a polyurethane layer and at least one layer is one of a melamine-formaldehyde layer or a phenolic resin layer.

[0019] In a preferred embodiment, the microcapsules comprise at least one polyurethane layer and at least one melamine-formaldehyde layer and at least one phenolic resin layer.

[0020] More preferably, the at least one melamine-formaldehyde layer is arranged between the at least one polyurea layer and the at least one phenolic resin layer.

[0021] Preferably, the at least three different layers are separated.

[0022] In a second aspect, the invention relates to a method for preparing microcapsules containing at least one component, preferably comprising at least one fragrance, the microcapsules comprising at least three layers surrounding said component, wherein in a first step (a), at least a first layer is prepared, wherein in a second step (b), at least a second layer is prepared, and wherein in a third step (c), at least a third layer is prepared, wherein the second layer is prepared after the first layer has hardened, and the third layer is prepared after the second layer has hardened.

[0023] According to a third aspect, the invention relates to microcapsules obtained by the method according to the invention.

[0024] Additionally, another aspect of the invention relates to a consumer product selected from the group consisting of: detergents and cleaning agents, personal care products, nutritional or recreational preparations, cosmetic or pharmaceutical preparations, perfuming agents, perfumed or to-be-perfumed products, preferably fragrance cleaners, laundry fragrances, the product comprising at least one microcapsule according to the invention.

[0025] Finally, the invention relates to the use of the microcapsules according to the invention for perfuming consumer products, preferably consumer products according to the invention.

[0026] That is, the inventors have found that the microcapsules according to the invention allow for the effective incorporation of active ingredients in encapsulated form, which exhibit excellent release characteristics (performance), into a wide range of solid consumer product formulations and the consumer products themselves. Thus, the at least three layers protect the fragile microcapsules from mechanical, chemical, and / or thermal influences during the preparation of the final consumer product (formulation) without negatively affecting the performance of the microcapsules within the consumer product (formulation). Based on this, the dosage form of the invention allows for the effective incorporation of active ingredients into solid consumer product formulations via the microcapsules while allowing for the effective and targeted release of said active ingredients, thus overcoming the disadvantages of the prior art.

[0027] This problem is solved by the object of the independent patent claims. Preferred embodiments are evident from the wording of the dependent patent claims and the following description.

[0028] Unless otherwise stated, all percentages are by weight and are based on the total weight of the microcapsules. Numerical examples given in the form of "x to y" include the values given. When multiple preferred numerical ranges are specified in this form, all ranges resulting from the combination of different endpoints are also included.

[0029] As used herein, the term "at least one" or "one or more" means one or more, such as two, three, four, five, six, seven, eight, nine or more.

[0030] The term "and / or" indicates an association or provides an alternative. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 : Figure 1 Schematically shows the structure of the microcapsules according to the invention;

[0032] Figure 2 : Figure 2 Shows the sensory evaluation results of the performance (i.e., release characteristics) of the microcapsules according to the invention. DETAILED DESCRIPTION

[0033] Hereinafter, the present invention will be described in more detail.

[0034] Thus, in a first aspect, the present invention relates to microcapsules comprising at least one ingredient, preferably comprising at least one fragrance, and at least three different layers surrounding said ingredient, wherein at least one layer is a polyurethane layer and at least one layer is one of a melamine - formaldehyde layer or a phenolic resin layer. Surprisingly, it has been found that such microcapsules have improved stability characteristics in addition to excellent release characteristics.

[0035] In a further preferred embodiment, the microcapsules with even more improved stability characteristics comprise at least one polyurethane layer and at least one melamine - formaldehyde layer and at least one phenolic resin layer.

[0036] Preferably, in a further preferred embodiment, the at least one melamine - formaldehyde layer is arranged between the at least one polyurea layer and the at least one phenolic resin layer. This can simplify the preparation of the microcapsules.

[0037] Preferably, in yet another embodiment, the at least one phenolic resin layer is the outer layer of the microcapsules. This can lead to a simplification of the preparation of the microcapsules, and further, this can improve the stability of the microcapsules.

[0038] Surprisingly, it has been found that microcapsules with excellent release characteristics (performance) can be obtained, wherein the at least one polyurethane layer is formed from tannic acid and at least one polyisocyanate, preferably at least one aromatic polyisocyanate, the at least one melamine - formaldehyde layer is formed from at least one melamine - formaldehyde pre - condensate in water or from at least melamine and formaldehyde as a single compound, and the at least one phenolic resin layer is formed from at least one aromatic polyol, preferably from phloroglucinol and / or resorcinol.

[0039] Preferably, the at least one aromatic polyisocyanate is at least bifunctional, preferably a polyfunctional polyisocyanate. In a preferred embodiment, the at least one aromatic polyisocyanate contains on average 2 to 5 -N=C=O functional groups. These include, for example, aromatic di-, tri- and higher polyisocyanates.

[0040] Preferably, the at least one polyisocyanate does not contain fewer than 2 -N=C=O functional groups. In particular, the at least one aromatic polyisocyanate is not a monoisocyanate.

[0041] According to the invention, the at least one polyisocyanate can be a mixture comprising two or more different polyisocyanates, preferably aromatic polyisocyanates each comprising two or more -N=C=O functional groups.

[0042] In a preferred embodiment, the at least one polyisocyanate is a mixture of an aromatic polyisocyanate (diisocyanate) comprising 2 -N=C=O functional groups and an aromatic polyisocyanate (triisocyanate) comprising 3 -N=C=O functional groups, wherein the at least one polyisocyanate (triisocyanate) having 3 -N=C=O functional groups is obtained from the aromatic polyisocyanate (diisocyanate) comprising 2 -N=C=O functional groups.

[0043] It has been found that capsules with excellent release properties are obtained by using a mixture of an aromatic diisocyanate and an aromatic polyisocyanate comprising 3 or more -N=C=O functional groups. Preferably, the amount of the aromatic diisocyanate in the mixture of the aromatic diisocyanate and the aromatic polyisocyanate comprising 3 or more -N=C=O functional groups is 0.2 wt% to 0.6 wt%, more preferably 0.25 wt% to 0.4 wt%, and in particular 0.3 wt%.

[0044] In a further embodiment of the invention, the at least one polyisocyanate is a mixture of an aromatic diisocyanate and an aromatic triisocyanate, wherein the aromatic diisocyanate comprises xylylene diisocyanate, more preferably isophthalic xylylene diisocyanate or consists thereof.

[0045] If the at least one polyisocyanate is a mixture of an aromatic diisocyanate and an aromatic triisocyanate, wherein the aromatic diisocyanate comprises xylylene diisocyanate, more preferably isophthalic xylylene diisocyanate or consists thereof, and wherein the amount of the aromatic diisocyanate is 0.2 wt% to 0.6 wt%, more preferably 0.25 wt% to 0.4 wt%, and in particular 0.3 wt%, then capsules with excellent release properties can be obtained.

[0046] In a preferred embodiment, the at least one polyisocyanate is a mixture of an aromatic polyisocyanate (diisocyanate) comprising 2 -N═C═O functional groups and an aromatic polyisocyanate (triisocyanate) comprising 3 -N═C═O functional groups, wherein the at least one polyisocyanate (triisocyanate) having 3 -N═C═O functional groups is derived from the aromatic polyisocyanate (diisocyanate) comprising 2 -N═C═O functional groups.

[0047] Furthermore, it has surprisingly been found that the microcapsules according to the invention (wherein the at least three different layers are separate layers) exhibit excellent release characteristics (properties).

[0048] Such separation can in particular be achieved by building the microcapsules layer by layer with a separate hardening step after the formation of each layer. The layers thus obtained are different and preferably non - connected.

[0049] Generally, a microcapsule is a particle comprising a core and a wall material surrounding the core, wherein the core can be a solid, liquid or gaseous substance or a mixture of substances surrounded by a polymeric dense, permeable or semi - permeable wall material. The wall is usually formed by emulsification and coagulation or precipitation of a polymer during interfacial polymerization. The core is also referred to as the inner phase. Other names for the wall include outer phase, shell or coating. The shell wall can comprise one or more layers and can include additional coatings with coating substances. The diameter of the microcapsules generally varies in the range from 1 μm to 1000 μm. The wall thickness is usually from 0.5 μm to 150 μm, but can vary in the range from 5·10 -9 m to 5·10 -6 m. Generally, the loading of the core material is from 25 wt% to 95 wt%, but those from 1 wt% to 99 wt% are also possible.

[0050] For example, hydrophobic active ingredients such as fragrances or aroma substances can be easily incorporated into many and different application formulations by encapsulation.

[0051] Based on their properties, microcapsules are particularly used in the printing industry, food industry (vitamins, seasonings, botanical extracts, enzymes, microorganisms), agro - chemistry (fertilizers, pesticides), feed industry (minerals, vitamins, enzymes, drugs, microorganisms), pharmaceutical industry, detergent industry and cosmetic industry, etc.

[0052] A variety of capsule wall or coating materials are known for manufacturing microcapsules. The capsule wall can be made of natural, semi-synthetic or synthetic materials. Natural shell materials include gum arabic, agar, agarose, maltodextrin, alginic acid or its salts (such as sodium alginate or calcium alginate), fats and fatty acids, cetyl alcohol, collagen, chitosan, lecithin, gelatin, albumin, shellac, polysaccharides (such as starch or dextran), polypeptides, protein hydrolysates, sucrose and waxes. Semi-synthetic capsule wall materials include chemically modified celluloses, especially cellulose esters, and cellulose ethers, such as cellulose acetate, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose and carboxymethyl cellulose, as well as starch derivatives, especially starch ethers and starch esters. Synthetic shell materials are, for example, polymers such as polyacrylates, polyamides, polyvinyl alcohol or polyvinylpyrrolidone.

[0053] Depending on the type of capsule wall material and the manufacturing method, microcapsules with different characteristics in terms of diameter, size distribution and physical and / or chemical properties are formed in each case.

[0054] Preferably, the microcapsules used within the scope of the present invention are microcapsules in which the shell of at least one microcapsule comprises or consists of a shell material selected from the group consisting of: sol-gel polymers (e.g., silica), polysiloxanes, polyacrylates, polyacrylamides, poly(acrylate-co-acrylamide), polyureas, polyurethanes, polyamides, polypeptides, polysulfonates, polysaccharides, polyphenol polymers, poly(melamine-formaldehyde), poly(resorcinol-formaldehyde), poly(urea-formaldehyde), poly(melamine-urea) or combinations thereof.

[0055] Preferably, the microcapsules according to the present invention are selected from the following group of capsule types, which consists of: microcapsules based on poly(melamine-formaldehyde) and isocyanate-based microcapsules, such as polyurea-based and / or polyurethane-based microcapsules, which are preferably biodegradable.

[0056] In the context of the present invention, microcapsules are understood as microparticles that include at least one or more active ingredients as core materials inside the capsule and are encapsulated by the capsule shell or capsule wall as described above. As the active ingredients to be encapsulated according to the present invention, any material that is substantially suitable for inclusion in microcapsules can be considered in the method according to the present invention. Preferably, hydrophobic or lipophilic, i.e., water-insoluble or water-immiscible liquids or solids and suspensions can be considered as the active ingredients to be encapsulated. These are mainly non-polar substances. Such hydrophobic substances are almost always lipophilic, i.e., they dissolve well in fats and oils. The terms "microcapsule" and "capsule" or "hydrophobic" and "lipophilic" are used synonymously in the context of the present invention.

[0057] In the context of the present specification, the core material is preferably a hydrophobic active substance, i.e., a substance having a specific function or causing a specific reaction, such as a drug, a pesticide, a cosmetic active ingredient, a food active ingredient, etc. In particular, the hydrophobic active substance is a lipophilic or hydrophobic fragrance or flavor substance or a lipophilic or hydrophobic perfume oil or flavor substance (i.e., a mixture of fragrance substances or flavor substances accordingly), a cooling agent, a TRPV1 or TRPV3 regulator, a substance that produces an irritating taste or a warm or hot sensation on the skin or mucous membrane or a tingling sensation in the mouth or throat, or an active ingredient having astringent effect, a pesticide, a biocide, an insecticide, a substance selected from the group consisting of: repellents, food additives, cosmetic active ingredients, pharmaceutical active ingredients, dyes, dye precursors; agrochemicals, dyes, luminescent paints, optical brighteners, solvents, waxes, silicone oils, lubricants, printing coatings for paper or a mixture of two or more of the above active ingredients.

[0058] The microcapsules in the context of the present invention may have a core material in the form of a hydrophobic single fragrance substance or single odor substance, wherein the core material comprises at least one single fragrance substance or single odor substance or a mixture thereof selected from the group consisting of:

[0059] Extracts of natural raw materials and their fractions or components isolated therefrom; single fragrance substances from a group of hydrocarbons; aliphatic alcohols; aliphatic aldehydes and acetals; aliphatic ketones and oximes; aliphatic sulfur-containing compounds; aliphatic nitriles; esters of aliphatic carboxylic acids; formates, acetates, propionates, isobutyrates, butyrates, isovalerates, valerates, hexanoates, crotonates, tiglinates and 3-methyl-2-butenoates of acyclic terpenic alcohols; acyclic terpene aldehydes and ketones and their dimethyl and diethyl acetals; formates, acetates, propionates, isobutyrates, butyrates, isovalerates, valerates, hexanoates, crotonates, tiglinates and 3-methyl-2-butenoates of cyclic terpenic alcohols; cyclic terpene aldehydes and ketones; cyclic alcohols; cyclic and cycloaliphatic ethers; cyclic and macrocyclic ketones; cycloaliphatic aldehydes; cycloaliphatic ketones; esters of cyclic alcohols; esters of cycloaliphatic carboxylic acids; aromatic hydrocarbons; araliphatic alcohols; esters of araliphatic alcohols and aliphatic carboxylic acids; araliphatic ethers; aromatic and araliphatic aldehydes; aromatic and araliphatic ketones; aromatic and araliphatic carboxylic acids and their esters; nitrogen-containing aromatic compounds; phenyl ethers and phenyl esters; heterocyclic compounds; lactones; and mixtures of the above active ingredients.

[0060] Specific examples of the above substances are known to those skilled in the art. Fragrance substances or odor substances and mixtures of two or more of said substances are chemical substances or compositions for imparting, giving and / or regulating a specific odor or odor impression. Preferably, the odor (impression) is considered to be pleasant.

[0061] In an alternative embodiment according to the present invention, the microcapsules according to the present invention use, respectively, an odoriferous substance or a perfume oil, or an odoriferous substance or an aromatic substance as the active ingredient to be encapsulated or as the core material. These are compositions containing at least one odoriferous substance or one aromatic substance. Such compositions, especially mixtures of odoriferous substances or perfume oils, preferably comprise two, three, four, five, six, seven, eight, nine, ten or more odoriferous substances. The perfume mixture or perfume oil is respectively preferably selected from the group consisting of: extracts of natural raw materials such as essential oils, concretes, absolutes, resins, balsams, oleoresins, tinctures such as ambergris oil; amyris oil; angelica seed oil; angelica root oil; anise oil; valerian oil; basil oil; tree moss absolute; bay oil; wormwood oil; benzoin resin; bergamot oil, beeswax absolute; birch tar; bitter almond oil; bergamot mint oil; buchu leaf oil; brazilwood oil; juniper oil; calamus oil; camphor oil; cananga oil; cardamom oil; caraway oil; cinnamon oil; acacia absolute; castoreum absolute; northern white cedar leaf oil; cypress oil; rockrose oil; citronella oil; lemon oil; copaiba balsam; copaiba balsam oil; coriander oil; costus root oil; cumin oil; cypress oil; artemisia oil; dill oil; dill seed oil; Eau de brouts absolute; oak moss absolute; olive oil; tarragon oil; lemon eucalyptus oil; eucalyptus oil; fennel oil; spruce needle oil; white pine oil; galbanum resin; galbanum oil, helichrysum absolute; helichrysum oil; ginger oil; iris root absolute; iris root oil; jasmine absolute; calamus oil; blue chamomile oil; roman chamomile oil; carrot seed oil; caraway oil; pine needle oil; curly mint oil; coriander seed oil; rockrose oil; rockrose absolute; rockrose resin; lavandin absolute; lavandin oil; lavender absolute; lavender oil; lemongrass oil; lovage oil; distilled lime oil; pressed lime oil; sandalwood oil; litsea cubeba oil; bay leaf oil; mace oil; marjoram oil; mandarin oil; massoia bark oil; mimosa absolute; musk seed oil; musk tincture; musk sage oil; musk oil; myrrh absolute; myrrh oil; myrtle oil; clove leaf oil; clove flower oil; neroli oil; frankincense absolute; frankincense oil; red myrrh oil; neroli absolute; orange oil; oregano oil; palmarosa oil; patchouli oil; perilla oil; peru balsam oil; parsley leaf oil; parsley seed oil; orange leaf oil; peppermint oil; pepper oil; pimento oil; pine oil; peppermint eucalyptus oil; rose absolute; rosewood oil; rose oil; rosemary oil; dalmatian sage oil; spanish sage oil; sandalwood oil; celery seed oil; lavandin oil; star anise oil; styrax oil; marigold oil; fir oil; tea tree oil; turpentine oil; thyme oil; tolu balsam; tuberose absolute; tuberose absolute; vanilla extract; violet leaf absolute; verbena oil; vetiver oil; juniper berry oil; wine yeast oil; mugwort oil; wintergreen oil; ylang-ylang oil; hyssop oil; civet absolute; cinnamon leaf oil; cinnamon bark oil; and their fractions or components isolated therefrom.

[0062] In a further variant of the present invention, the fragrance substance may also be encapsulated as core material in the form of a single fragrance substance, where the core material comprises at least one single fragrance substance or a mixture thereof as active ingredient.

[0063] However, preferably, a single fragrance substance or odorant (i.e., chemical compounds having an odor or smell and thus all natural and synthetic substances that impart an olfactorily perceivable odor) or alternatively a mixture of fragrance substances or odorants (so-called perfume oils) is used as the active ingredient encapsulated by the microcapsule shell. More preferably, the substances and mixtures of substances impart a pleasant odor to the consumer product.

[0064] In a preferred variant of the present invention, all microcapsules according to the present invention are loaded with the same active ingredient, for example all microcapsules comprise a fragrance substance and even more preferably the same fragrance substance.

[0065] According to an alternative embodiment, the microcapsules according to the present invention encapsulate different types of active ingredients or different substances among the same type of active ingredient.

[0066] Therefore, preferably, the core material is selected regardless of the shell material.

[0067] The composition of the present invention comprising microcapsules encapsulating an active ingredient is effectively incorporated into a variety of solid consumer product formulations, thereby allowing for effective and targeted release of the active ingredient. Thus, the presence of at least three layers, preferably at least three different layers, acts as a shock-absorbing layer that protects the microcapsules from damage caused by mechanical, chemical, and / or thermal influences and thus prevents premature release and degradation of the active ingredient during the preparation of the consumer product.

[0068] In addition, the microcapsules of the present invention may further comprise one or more ingredients that improve the visual aesthetics of the final consumer product such as colorants. In addition, the microcapsules may comprise additives and / or active ingredients such as optical brighteners, detergents, laundry active agents, etc.

[0069] Preparation method :

[0070] According to a second aspect, the present invention relates to a method for preparing microcapsules containing at least one ingredient, preferably comprising at least one fragrance agent, the microcapsules comprising at least three layers surrounding the ingredient, where in a first step (a), at least a first layer is prepared, where in a second step (b), at least a second layer is prepared, and where in a third step (c), at least a third layer is prepared, where the second layer is prepared after the first layer has hardened, and the third layer is prepared after the second layer has hardened.

[0071] Preferably, in the first step (a), the first layer is prepared by the following sub-steps:

[0072] (i) Providing a non-aqueous phase comprising at least one polyisocyanate compound and at least one component, preferably comprising at least one fragrance, and;

[0073] (ii) Providing an aqueous phase comprising at least one alcohol compound and optionally at least one stabilizer and / or at least one emulsifier;

[0074] (iii) Emulsifying or dispersing the non-aqueous phase in the aqueous phase to obtain an oil-in-water emulsion or dispersion;

[0075] (iv) Hardening to obtain the first layer.

[0076] Preferably,

[0077] - In sub-step (i), the at least one polyisocyanate compound is an aromatic polyisocyanate, more preferably having at least two isocyanate groups;

[0078] And / or

[0079] - In sub-step (ii), the aqueous phase is prepared by solvating at least one alcohol compound comprising at least two hydroxyl groups, preferably by solvating a polyol, especially an aromatic polyol, and an emulsifier in water.

[0080] Preferably, in sub-step (iv), the hardening is carried out in the temperature range of 20 °C to 40 °C, and the hardening time is between 10 minutes and 120 minutes, preferably between 20 minutes and 60 minutes, more preferably between 25 minutes and 45 minutes.

[0081] Thus, in a preferred embodiment, the first layer of the microcapsules is a polyurethane layer.

[0082] In sub-step (i), the amount of the at least one polyisocyanate compound is 0.1 wt% to 0.8 wt%, preferably 0.2 wt% to 0.5 wt%, more preferably 0.25 wt% to 0.35 wt%, and most preferably 0.27 wt% to 0.3 wt%.

[0083] In sub-step (i), the amount of the at least one component preferably comprising at least one fragrance is 10 wt% to 60 wt%, preferably 20 wt% to 55 wt%, more preferably 35 wt% to 45 wt%.

[0084] In sub-step (i), the at least one polyisocyanate is a mixture of two or more different polyisocyanates, preferably aromatic polyisocyanates each comprising two or more -N=C=O functional groups. Preferably, the amount of the aromatic diisocyanate in the mixture comprising the aromatic diisocyanate and the aromatic triisocyanate is 0.2% to 0.6% by weight of the mixture, more preferably 0.25% to 0.4% by weight, and in particular 0.3% by weight.

[0085] In a further embodiment of the invention, the at least one polyisocyanate is a mixture of an aromatic diisocyanate and an aromatic triisocyanate, wherein the aromatic diisocyanate comprises xylylene diisocyanate, more preferably m-xylylene diisocyanate or consists thereof.

[0086] Preferably, in sub-step (i), the at least one polyisocyanate is a mixture of an aromatic diisocyanate and an aromatic triisocyanate, wherein the aromatic diisocyanate comprises xylylene diisocyanate, more preferably m-xylylene diisocyanate or consists thereof, wherein the amount of the aromatic diisocyanate is 0.2% to 0.6% by weight, more preferably 0.25% to 0.4% by weight, and in particular 0.3% by weight, and wherein the mixture further comprises at least one Lewis base. Preferably, the amount of the at least one Lewis base is 15% to 45% by weight of the mixture of the aromatic diisocyanate and the aromatic triisocyanate, preferably 20% to 30% by weight, in particular 25% by weight, wherein the aromatic diisocyanate comprises xylylene diisocyanate, more preferably m-xylylene diisocyanate or consists thereof, wherein the amount of the aromatic diisocyanate is 0.2% to 0.6% by weight, more preferably 0.25% to 0.4% by weight, and in particular 0.3% by weight, wherein the mixture further comprises at least one Lewis base.

[0087] In a preferred embodiment, the at least one Lewis base is ethyl acetate.

[0088] In sub-step (ii), the amount of the at least one alcohol compound is 0.01% to 0.3% by weight, preferably 0.05% to 0.2% by weight, more preferably 0.08% to 0.12% by weight.

[0089] In sub-step (ii), the amount of the optional at least one stabilizer and / or at least one emulsifier compound is 1.0% to 10% by weight, preferably 2% to 5% by weight, more preferably 3% to 4% by weight.

[0090] Preferably, in the second step (b), the second layer is prepared by the following sub-steps:

[0091] (v) Solvate the melamine - formaldehyde pre - condensate in water or solvate a mixture of melamine and formaldehyde in water to obtain a solution;

[0092] (vi) Optionally add at least one catalyst;

[0093] (vii) Harden to obtain the second layer.

[0094] Preferably, in sub - step (vi), the solution obtained in sub - step (v) is acidified by the at least one catalyst to a pH in the range of 3 to 4, preferably 3.25 to 3.75, more preferably to 3.5.

[0095] Optionally, in sub - step (vii), the hardening is carried out in a temperature range of 30 °C to 70 °C, preferably 40 °C to 60 °C, more preferably 45 °C to 55 °C.

[0096] In sub - step (vi), the amount of the at least one catalyst is 0.05 wt% to 0.5 wt%, preferably 0.1 wt% to 0.4 wt%, more preferably 0.2 wt% to 0.3 wt%.

[0097] In sub - step (vi), the solution obtained in sub - step (v) is acidified by the at least one catalyst to a pH in the range of 3 to 4, preferably 3.25 to 3.75, more preferably to 3.5.

[0098] Thus, in a preferred embodiment, the second layer of the microcapsule is a melamine - formaldehyde layer.

[0099] In sub - step (v), the amount of the melamine - formaldehyde pre - condensate is 0.5 wt% to 5 wt%, preferably 1 wt% to 3.5 wt%, more preferably 1.5 wt% to 2 wt%.

[0100] Preferably, in the third step (c), the third layer is prepared by the following sub - steps:

[0101] (viii) Add at least one alcohol compound to the second layer;

[0102] (ix) Harden to obtain the third layer.

[0103] In one embodiment of the present invention,

[0104] - In sub - step (viii), the at least one alcohol compound is preferably an aromatic polyol,

[0105] More preferably phloroglucinol and / or resorcinol;

[0106] And / or

[0107] - In sub-step (viii), the at least one alcohol compound is added as a solid, preferably in batches.

[0108] In sub-step (viii), the amount of the at least one alcohol compound is from 0.01% to 0.3% by weight, preferably from 0.05% to 0.2% by weight, more preferably from 0.08% to 0.12% by weight.

[0109] In another embodiment of the present invention, in sub-step (ix), curing is carried out in the temperature range of 20 °C to 100 °C, preferably 70 °C to 90 °C, more preferably 75 °C to 85 °C, and the curing time is between 30 minutes and 360 minutes, preferably between 60 minutes and 240 minutes.

[0110] Thus, in a preferred embodiment, the third layer of the microcapsules is preferably a phenolic resin layer.

[0111] Optionally, in a further sub-step (x), at least one amino-containing compound, preferably urea, is added, preferably as a solid after sub-step (ix).

[0112] In sub-step (x), the amount of the at least one amino-containing compound (preferably urea) is from 0.1% to 0.8% by weight, preferably from 0.25% to 0.6% by weight, more preferably from 0.4% to 0.5% by weight.

[0113] Optionally, in a further sub-step (xi), cooling is carried out to a temperature of 40 °C to 50 °C, preferably 42 °C to 48 °C, especially 45 °C, after sub-step (ix).

[0114] Optionally, in a further sub-step (xii), the pH value is adjusted to a range of 5 to 6, preferably to 5.3 to 5.7, more preferably to 5.5, after sub-step (xi) to obtain a slurry.

[0115] Optionally, in a further sub-step (xiii), the slurry obtained from sub-step (xii) is filtered and thickened.

[0116] In a preferred embodiment of the present invention, in a further sub-step (x), at least one amino compound, preferably urea, is added, preferably as a solid after sub-step (ix). In a subsequent sub-step (xi), cooling is carried out to a temperature of 40 °C to 50 °C, preferably 42 °C to 48 °C, in particular to 45 °C, and subsequently the pH value is adjusted to a range of 5 to 6, preferably to 5.3 to 5.7, more preferably to 5.5 after sub-step (xii) to obtain a slurry. Finally, in a further sub-step (xiii), the slurry obtained from sub-step (xii) is filtered and thickened. The microcapsules thus obtain three separate layers and thus have improved stability in addition to excellent release characteristics.

[0117] In a preferred embodiment, the at least first layer and the at least second layer and the at least third layer are prepared in a single tank. In particular, a hardening step is carried out after the formation of each layer. This allows for the efficient and simplified preparation of microcapsules with excellent release characteristics and improved stability.

[0118] To achieve a uniform distribution of the microcapsules, it is advantageous to use microcapsules having a particle size in the range of 150 μm to 5 mm, preferably in the range of 500 μm to 3 mm. Thus, according to a preferred variant of the present invention, the particle size of the microcapsules according to the present invention is preferably in the range of 150 μm to 5 mm, preferably in the range of 500 μm to 3 mm.

[0119] Additionally, a further aspect of the present invention relates to microcapsules prepared by the method according to the present invention.

[0120] Additionally, a further aspect of the present invention relates to microcapsules prepared by the method according to the present invention.

[0121] Consumer goods :

[0122] In another aspect, the present invention relates to the use of the microcapsules according to the present invention in the preparation of consumer product formulations. The terms "consumer product formulation" and "consumer product" are used synonymously in the context of the present invention.

[0123] Considering the preparation of solid consumer products such as powder detergents, laundry soaps, solid fabric softeners, deodorant sticks, etc., particular advantages of the microcapsules of the present invention obtained by the preparation method according to the present invention have been found. Thus, preferably, the consumer product according to the present invention is a solid consumer product.

[0124] Accordingly, in another preferred variant, the present invention also relates to the use of the microcapsules according to the present invention for the preparation of consumer goods and their formulations, wherein the consumer goods or consumer goods formulations are solid products, such as textile care products (such as powder detergents, laundry soaps, solid fabric softeners), solid soaps, household products (such as solid WC cleaners, solid general cleaners, powdered carpet cleaners, powdered detergents for washing dishes or for cleaning various surfaces), personal care products (such as deodorants, soaps), fragrance enhancers, aroma enhancers, pharmaceutical products, and mixtures thereof.

[0125] Finally, in another aspect, the present invention relates to a consumer good or a consumer good formulation that comprises or consists of the microcapsules according to the present invention.

[0126] The microcapsules of the present invention allow for the effective incorporation of active ingredients into solid product formulations, thereby allowing for the effective and targeted release of the active ingredients.

[0127] Example

[0128] Hereinafter, the present invention will be described in more detail and specifically with reference to examples, which, however, are not intended to limit the present invention.

[0129] Example 1: Preparation of microcapsules

[0130] According to the first example, Lupasol PA-140 was dissolved in water, and tannic acid was added to the solution. The essential oil and Takenate D-110N were mixed and added. For obtaining the first layer, hardening was carried out at 35 °C for 30 minutes. Then, an aqueous solution of melamine-formaldehyde precondensate was added, and subsequently a catalyst was added to initiate the polymerization reaction. As the catalyst, formic acid was added and the pH was adjusted to 3.5. For obtaining the second layer, hardening was carried out by heating to 50 °C. Then, phloroglucinol was added and the temperature was raised to further carry out the curing step to obtain the third layer. After adding urea, it was cooled to 45 °C, the pH was adjusted to 5.5, and then thickened to obtain the microcapsules.

[0131] Thus, the microcapsules according to the present invention comprise at least one ingredient, preferably at least one aroma, and at least three different layers surrounding the ingredient, wherein at least one layer is a polyurethane layer, and at least one layer is one of a melamine-formaldehyde layer or a phenolic resin layer (see Figure 1 ).

[0132] Specifically, the microcapsules obtained by the present invention as described above may include a first layer that is a polyurethane layer. The first layer can also be understood as the inner layer. Thus, the third layer (currently phenolic resin or formaldehyde-phenol-resin or phenolic resin) can be understood as the outer layer. Therefore, the second layer (currently melamine-formaldehyde layer) is disposed between the first layer and the third layer.

[0133] According to the present invention, the microcapsules may include more layers. Preferably, the layers may be, but are not limited to, polyurethane, phenolic resin, and / or melamine-formaldehyde.

[0134] Sensory evaluation is carried out as follows: After preparing the microcapsules according to the present invention as described above, they are combined with a commercially available powder detergent.

[0135] Application of microcapsules in powder detergents

[0136] The microcapsules are sprayed (45 Psi, 5.5 kg / h) and collected, simulating the spray process application. The sprayed microcapsules are used in a powder detergent non-aromatic base (0.11%) and mixed to have a uniform application.

[0137] Scheme for hand-washing towels with powder detergents

[0138] The powder detergent is diluted in 1 L of tap water at 5 g per towel in a container. The towel is placed in the container and cycled 10 times to simulate the washing movement. Then the towel is held in the container for 15 minutes, squeezed or scrubbed by hand and rinsed with 1 L of water (per towel). Then the towel is squeezed again and air dried.

[0139] Preparation of samples

[0140] The fragrance intensity of the dry towel is evaluated before and after rubbing. Thus, a quantitative descriptive test or analytical test is carried out, which is a descriptive test for determining the intensity of several attributes in the product. A trained evaluation panel tests the towel using the following rating scale from 1 to 10.

[0141] Eight to ten testers rate the fragrance intensity on a scale of 1 (imperceptible) to 10 (extremely strong).

[0142] The results of the sensory evaluation are shown in Figure 2 As shown, the microcapsules according to the present invention have improved release characteristics (after rubbing).

Claims

1. A microcapsule, said microcapsule comprising at least one component, preferably comprising at least one fragrance, and at least three different layers surrounding said component, wherein at least one layer is a polyurethane layer and at least one layer is one of a melamine - formaldehyde layer or a phenolic resin layer.

2. The microcapsule according to claim 1, said microcapsule comprising at least one polyurethane layer, at least one melamine - formaldehyde layer and at least one phenolic resin layer.

3. The microcapsule according to claim 2, wherein said at least one melamine - formaldehyde layer is arranged between said at least one polyurea layer and said at least one phenolic resin layer.

4. The microcapsule according to any one of claims 1 to 3, wherein said at least one phenolic resin layer is the outer layer.

5. The microcapsule according to any one of claims 1 to 4, wherein said at least one polyurethane layer is formed from tannic acid and at least one polyisocyanate, preferably at least one aromatic polyisocyanate, more preferably said at least one polyisocyanate is a mixture of an aromatic diisocyanate and an aromatic triisocyanate, wherein said at least one melamine - formaldehyde layer is formed from at least one melamine - formaldehyde pre - condensate in water or from at least melamine and formaldehyde as a single compound, and said at least one phenolic resin layer is formed from at least one aromatic polyol, preferably from phloroglucinol and / or resorcinol.

6. The microcapsule according to any one of claims 1 to 5, wherein said at least three different layers are separated.

7. A method for preparing a microcapsule containing at least one component, preferably comprising at least one fragrance, said microcapsule comprising at least three layers surrounding said component, wherein in a first step (a), at least a first layer is prepared, wherein in a second step (b), at least a second layer is prepared, and wherein in a third step (c), at least a third layer is prepared, wherein said second layer is prepared after said first layer is hardened, and said third layer is prepared after said second layer is hardened.

8. The method according to claim 7, wherein in said first step (a), said first layer is prepared by the following sub - steps: (i) providing a non - aqueous phase, said non - aqueous phase comprising at least one polyisocyanate compound and at least one component, preferably comprising at least one fragrance, and; (ii) providing an aqueous phase, said aqueous phase comprising at least one alcohol compound and optionally at least one stabilizer and / or at least one emulsifier; (iii) emulsifying or dispersing said non - aqueous phase in said aqueous phase to obtain an oil - in - water emulsion or dispersion; (iv) hardening to obtain said first layer.

9. The method according to claim 8, wherein - in sub - step (i), said at least one polyisocyanate compound is an aromatic polyisocyanate, more preferably having at least two isocyanate groups, even more preferably said at least one polyisocyanate is a mixture of an aromatic diisocyanate and an aromatic triisocyanate; and / or - In sub-step (ii), the aqueous phase is prepared by solvating at least one alcohol compound comprising at least two hydroxyl groups, preferably by solvating a polyol, in particular an aromatic polyol, and an emulsifier in water.

10. The method according to any one of claims 7 to 9, wherein in sub-step (iv), the hardening is carried out in the temperature range of 20 °C to 40 °C, and the hardening time is between 10 minutes and 120 minutes, preferably between 20 minutes and 60 minutes, more preferably between 25 minutes and 45 minutes.

11. The method according to any one of claims 7 to 10, wherein in the second step (b), the second layer is prepared by the following sub-steps: (v) Solvating a melamine-formaldehyde pre-condensate in water or solvating a mixture of melamine and formaldehyde in water to obtain a solution; (vi) Optionally adding at least one catalyst; (vii) Hardening to obtain the second layer.

12. The method according to claim 11, wherein in sub-step (vi), the solution obtained in sub-step (v) is acidified to a pH in the range of 3 to 4, preferably 3.25 to 3.75, more preferably to 3.5, by the at least one catalyst.

13. The method according to claim 11 and / or 12, wherein in sub-step (vii), the hardening is carried out in the temperature range of 30 °C to 70 °C, preferably 40 °C to 60 °C, more preferably 45 °C to 55 °C.

14. The method according to any one of claims 7 to 13, wherein in the third step (c), the third layer is prepared by the following sub-steps: (viii) Adding at least one alcohol compound to the second layer; (ix) Hardening to obtain the third layer.

15. The method according to claim 14, wherein - In sub-step (viii), the at least one alcohol compound is preferably an aromatic polyol, more preferably phloroglucinol and / or resorcinol; and / or - In sub-step (viii), the at least one alcohol compound is added as a solid, preferably in batches.

16. The method according to claim 14 and / or 15, wherein in sub-step (ix), the hardening is carried out in the temperature range of 20 °C to 100 °C, preferably 70 °C to 90 °C, more preferably 75 °C to 85 °C, and the hardening time is between 30 minutes and 360 minutes, preferably between 60 minutes and 240 minutes.

17. The method according to any one of claims 7 to 16, wherein in an additional sub-step (x), at least one amino compound, preferably urea, is added, preferably as a solid after sub-step (ix).

18. The method according to any one of claims 7 to 17, wherein in an additional sub-step (xi), cooling is carried out to a temperature of 40 °C to 50 °C, preferably 42 °C to 48 °C, in particular 45 °C, after sub-step (ix).

19. The method according to claim 18, wherein in a further sub-step (xii), after sub-step (xi), the pH value is adjusted to a range of 5 to 6, preferably to 5.3 to 5.7, more preferably to 5.5 to obtain a slurry.

20. The method according to claim 19, wherein in a further sub-step (xiii), the slurry obtained from sub-step (xii) is filtered and thickened.

21. The method according to any one of claims 7 to 20, wherein the at least first layer and the at least second layer and the at least third layer are prepared in a single tank.

22. Microcapsules obtained by the method according to any one of claims 1 to 21.

23. A consumer product selected from the group consisting of: detergents and cleaning agents, personal care products, nutritional or entertainment preparations, cosmetic or pharmaceutical preparations, perfumes, perfumed or to-be-perfumed products, preferably fragrance cleaners, laundry fragrances, the consumer product comprising at least one microcapsule according to one or more of claims 1 to 6 or 21.

24. Use of the microcapsules according to claims 1 to 6 or 21 for perfuming a consumer product, preferably the consumer product according to claim 23.

Images