Microcapsules and encapsulation thereof

Abstract

The present invention relates to microcapsules based on a polymeric shell and a lipophilic active core material with improved thermal stability.

Description

Technical Field

[0001] The present invention relates to a microcapsule based on a formaldehyde-free polymer shell and a lipophilic active core material with improved thermal stability. The microcapsule with a cross-linked acrylate vinyl copolymer shell confers the benefit of high thermal stability, so that the microcapsule shell is only destroyed at temperatures above 250°C, and the shell prevents core leakage for a long time at higher temperatures (120°C for 30 minutes). This makes the microcapsule suitable for applications at high temperatures as well as applications under ambient conditions. The present invention also relates to a method for making the microcapsule. Background Art

[0002] Most leave-on and rinse-off formulations (including cosmetic formulations) contain fragrances or perfumes to give a pleasant smell to the formulation itself or to the surface to which the formulation is applied (whether textiles, skin or hair). Fragrances or perfumes are generally compounds that are sensitive to various chemicals and oxidation, and therefore require encapsulation. Therefore, undesirable interactions with other ingredients of the formulation (such as surfactants) can lead to changes in the fragrance notes. In addition, fragrances or perfumes are mostly highly volatile. Therefore, most of the fragrance amount initially added to the formulation volatilizes before the application time and the remaining fragrance amount actually applied to the treated surface will also evaporate in a short time. In order to overcome these problems, it has been proposed to incorporate fragrances or perfumes in microcapsules into the formulation. These microcapsules enable valuable fragrances or perfumes to be distributed relatively evenly in the formulation without having to be exposed to other ingredients during storage. Proper selection of the shell of the capsule also enables effects to be achieved in this way, such as delayed release or release on demand when rubbed or release at higher temperatures.

[0003] WO2014 / 189980A1 describes an encapsulated benefit agent population having a population diameter variation coefficient of 6% to 50, preferably 8% to 35, more preferably 12% to about 25, the encapsulated benefit agent population comprising encapsulated benefit agents having an average diameter of 3 to 300 microns, preferably 5 to 240 microns, more preferably 10 to 120 microns, the encapsulated benefit agents comprising a core and a shell encapsulating the core, the shell comprising a polymer, preferably a film-forming polymer, the shell having a thickness of 0.5 to 15 microns, preferably 1 to 8 microns, more preferably 1.5 to 6 microns and the coefficient of variation of the shell thickness is 2 to 30, preferably 4 to 25, more preferably 6 to 20. Also included is an encapsulated benefit agent population according to claim 1, wherein the shell material comprises polyvinyl alcohol, polyvinyl acetate, polyvinyl pyrrolidone, polyvinyl acetate phthalate, vinyl acetate neodecanoate copolymer, vinyl acetate ethylene copolymer, vinyl acetate crotonate neodecanoate copolymer, vinyl acetate crotonic acid copolymer, vinyl acetate butyl maleate copolymer, cellulose acetate, cellulose acetate phthalate, ethyl cellulose, hydroxypropyl methylcellulose phthalate, cellulose acetate butyrate, vinyl pyrrolidone vinyl acetate copolymer, poly(styrene-maleic acid) isobutyl ester, poly(styrene-butadiene copolymer), poly(styrene-acrylic acid copolymer) and mixtures thereof, but does not involve microcapsules with high thermal stability.

[0004] WO2012 / 162742 (also published as AU2011902127, EP2714817, CN104053729, US9339781B2, AU2012262664B2, NZ618219 or CA2837897) teaches a method for preparing an aqueous dispersion of a polymer-encapsulated particulate material, the method comprising: providing a dispersion of the particulate material in a continuous aqueous phase, the dispersion comprising an ethylenically unsaturated monomer and a stabilizer for the particulate material; and Ethylenically unsaturated monomers are polymerized to form a polymer that encapsulates a particulate material, thereby providing an aqueous dispersion of the polymer-encapsulated particulate material; wherein the polymerization of the ethylenically unsaturated monomers comprises: (a) polymerizing a monomer composition comprising ionizable ethylenically unsaturated monomers to form an alkali-responsive, water-swellable, non-reactive polymer layer that encapsulates the particulate material; and (b) polymerizing a monomer composition comprising non-ionizable ethylenically unsaturated monomers to form an extensible, water- and alkali-permeable, non-reactive polymer layer that encapsulates the alkali-responsive, water-swellable polymer layer.

[0005] WO2012 / 162742 also teaches polymers encapsulating the obtained particulate material, which is encapsulated by a base-responsive water-swellable non-living polymer layer comprising polymerized residues of ionizable ethylenically unsaturated monomers, wherein the base-responsive water-swellable non-living polymer layer is encapsulated by an extendible, water- and base-permeable non-living polymer layer comprising polymerized residues of non-ionizable ethylenically unsaturated monomers, but does not involve microcapsules with high thermal stability.

[0006] WO2017004339(A1) teaches a consumer product comprising a composition comprising: an auxiliary material; a first population of microcapsules having a first median volume weighted particle size and comprising microcapsules comprising a partitioning regulator and a first fragrance oil in a first weight ratio; and a second population of microcapsules having a second median volume weighted particle size and comprising microcapsules comprising a partitioning regulator and a second fragrance oil in a second weight ratio; wherein the first weight ratio and the second weight ratio are different, and / or the first median volume weighted particle size and the second median volume weighted particle size are different; wherein the composition is a fabric and home care composition, thus relating to a consumer product having two different microcapsule populations and does not teach microcapsules with high thermal stability.

[0007] WO2005 / 002719 teaches a method for preparing microcapsules, which comprises the following steps:

[0008] (a) mixing a free radical polymerizable and ethylenically unsaturated monomer, an emulsifier, a super hydrophobe, a hydrophobic material, an initiator and deionized water to prepare a miniemulsion; and (b) polymerizing the miniemulsion to prepare microcapsules, but not making the microcapsules have high thermal stability.

[0009] US2012076843 (A1) teaches a microcapsule comprising a capsule core and a capsule wall, which can be obtained by a process comprising free radical polymerization of an oil-in-water emulsion, wherein the oil-in-water emulsion comprises the following ingredients: 30 to 90 wt% of one or more monomers (monomer I), selected from C1-C24 alkyl esters of acrylic acid and / or methacrylic acid, acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid, based on the total weight of the monomers; 10 to 70 wt% of one or more ethylenically unsaturated crosslinkers (monomer II), based on the total weight of the monomers, wherein at least 10 wt% is a highly branched polymer crosslinker, based on the total weight of the monomers I, II and III; 0 to 30 wt% of one or more monounsaturated monomers (monomer III) different from monomer I, based on the total weight of the monomers, and a hydrophobic core material. However, it does not teach microcapsules with high thermal stability.

[0010] WO2019 / 121736 teaches an encapsulated fragrance composition comprising at least one core-shell microcapsule suspended in a suspension medium, wherein the at least one core-shell microcapsule comprises a core containing at least one fragrance ingredient, and a shell surrounding or at least partially surrounding the core, wherein the shell comprises a thermosetting resin formed by the reaction of a shell-forming material selected from monomers, prepolymers and / or precondensates, and wherein the encapsulated fragrance composition comprises a polymer stabilizer, which is a reaction product of a polymer surfactant and a silane containing a functional group capable of forming a covalent bond with the shell. However, the thermal stability of the microcapsule composition according to this prior art is not disclosed.

[0011] WO2020190689 (also published as US2020 / 0315931 A1) teaches a population of microcapsules comprising a capsule core and a capsule shell (the capsule shell is hydrolyzable), the microcapsules being made by an oil-in-water microencapsulation process, the microencapsulation process comprising: a) dispersing a polymer emulsifier and an optional initiator in an aqueous phase; b) dispersing the following in one or more oil phases: i) an initiator and a core material, ii) a first multifunctional (meth)acrylate monomer having an average of more than one ester group and a hydrophilicity index of less than 20, iii) a second multifunctional (meth)acrylate monomer, the second multifunctional (meth)acrylate comprising a hydrophilic multifunctional polar monomer having a hydrophilicity index of at least 20, and the second multifunctional polar monomer accounting for 50% or less of the capsule shell, wherein the first and second multifunctional (meth)acrylate monomers are 5) methacrylate monomers, iv) acidic (meth)acrylate monomers or at least one oil-soluble or oil-dispersible simple acid or both, the acidic (meth)acrylate monomers having one or more groups selected from carboxyl and sulfonic acid groups, and v) optionally 0 to 50% by weight of an aliphatic polyester having two or more acrylate or methacrylate groups; c) emulsifying one or more oil phases into an aqueous phase under high shear agitation to form an oil-in-water emulsion comprising droplets of core material and oil phase monomers dispersed in the aqueous phase; d) activating one or more initiators by heat or actinic radiation to react the monomers and the optional aliphatic polyester to form a polymer capsule shell around the emulsion droplets. Thus, this prior art teaches multifunctional (meth)acrylate monomers as a shell wall variant, which does not involve vinyl acetate monomers, but rather involves polyvinyl pyrrolidone participating in the formation of the microcapsule shell together with butyl acrylate, and does not involve capsules with increased thermal stability.

[0012] CN109453724A discloses a method for preparing a sustained-release microcapsule with multiple cores inside. The preparation method comprises the following steps: dispersing a suspension mixed with an acrylate polymer, a volatile organic solvent, a liquid flavor and a porous starch into a colloidal protective agent aqueous solution by mechanical stirring to form an oil-in-water system; then decompressing to remove the volatile organic solvent in the oil-in-water system, and performing interfacial phase separation on the acrylate polymer, the liquid flavor and the porous starch to form an acrylate polymer microcapsule with liquid flavor and porous starch wrapped inside; and further adding ethylene glycol dimethacrylate prepolymer, and heating and curing to obtain a cross-linked acrylate polymer flavor microcapsule with multiple cores inside, that is, a sustained-release microcapsule with multiple cores inside. The method is simple to operate and has high efficiency in preparation, and the wrapped flavor can be gradually released, the fragrance is long-lasting, and it can be widely used in the fields of cosmetics, household goods or personal care products and functional materials.

[0013] US20170211019 (also published as WO 2017 / 132101A1, JP 6651637B2 or EP3408363A1) teaches a composition comprising, based on the total composition weight: a) about 0.01% to about 1% of a polymer material, the polymer material comprising a first polymer and a second polymer; the first polymer is derived from polymerization of about 5 to about 100 mole percent of a cationic vinyl addition monomer, about 0 to about 95 mole percent of a nonionic vinyl addition monomer, about 50 ppm to about 1,950 ppm of a crosslinking agent comprising two or more ethylenic functional groups, and about 0 ppm to about 10,000 ppm of a chain transfer agent; the second polymer is derived from polymerization of about 5 to about 100 mole percent of a cationic vinyl addition monomer, about 0 to about 95 mole percent of a nonionic vinyl addition monomer, about 50 ppm to about 1,950 ppm of a crosslinking agent comprising two or more ethylenic functional groups, and about 0 ppm to about 10,000 ppm of a chain transfer agent; The invention relates to a method for preparing a fabric and home care product comprising: a) polymerizing from about 0 ppm to about 45 ppm of a cationic vinyl addition monomer, from about 0 to about 95 mole percent of a nonionic vinyl addition monomer, from about 0 ppm to about 45 ppm of a crosslinker containing two or more ethylenic functional groups, and from about 0 ppm to about 10,000 ppm of a chain transfer agent; b) from about 0% to about 35% of a cationic quaternary ammonium salt fabric softener active material, the parent fatty acyl compound or acid from which the alkyl or alkenyl chain is derived having an iodine value of from about 5 to about 60; and c) a population of perfume microcapsules, provided that the population of perfume microcapsules comprises a microcapsule wall material, the microcapsule wall material comprising one or more polyacrylate polymers; the composition is a fabric and home care product. The polymer is derived from: (iii) an anionic monomer selected from acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, and a monomer performing a sulfonic acid or phosphonic acid function, such as 2-acrylamido-2-methylpropane sulfonic acid and its salts. The perfume microcapsules comprise a microcapsule wall material comprising primarily quaternary ammonium type cationic vinyl addition monomers, and no improved microcapsule thermal stability is taught.

[0014] WO 2017123965 (also published as US2019 / 0054440 A1, AU2017207981B2, EP3402674, CN108778730B, BR112018014242, US20190054440, JP2019505375 (JP 6938514B2), CA3011107, IN201817026022, MX2018008726) teach a microcapsule comprising: i. a lipophilic core material, and ii. a microcapsule shell; wherein the microcapsule shell is formed by oil-in-water emulsion polymerization of a monomer mixture, and the monomer mixture is mainly composed of: (a) greater than 70 to about 99 weight % of at least one multifunctional ethylenically unsaturated monomer, (b) about 1 to about 30 weight % of at least one unsaturated carboxylic acid monomer or its ester, and (c) about 0 to about 30 weight % of at least one vinyl monomer.

[0015] WO2017040759 (also disclosed as CA2980193, CN107530672, AU2016317844, EP3344382) teaches an aqueous slurry composition comprising an aqueous medium in which microcapsules containing an oil medium are dispersed, wherein the microcapsules containing the oil medium comprise an ionic acrylate copolymer shell encapsulating the oil medium. Therefore, only microcapsules based on acrylic polymers are taught, without involving any shell structure based on methyl (acrylic acid)-vinyl acetate copolymers, to obtain thermally stable microcapsules through a unique process.

[0016] EP2397120B2 (also published as WO 2011 / 158962, ES2597980, US9464263B2, CN102946843, BR112012032063, JP2013530253, MX344969) teaches a liquid consumer product having a density in the range of 0.900 g / cm 3 Up to 1.400g / cm 3 , preferably 0.900g / cm 3 Up to 1.250g / cm 3 , and comprising core-shell microcapsules, wherein:

[0017] The microcapsule shell is formaldehyde-free and is made from starting materials such that 50% to 100% by weight of said materials have a density equal to or less than 1.05 g / cm 3 ;

[0018] -The microcapsule core contains a fragrance composition comprising:

[0019] a) 20-100 wt.% of at least one cyclic aromatic material having a density greater than 0.950

[0020] g / cm 3 and ClogP is in the range of 1.00 to 6.00;

[0021] b) 0-50% by weight of at least one oil-soluble organic compound having a density greater than 0.950

[0022] g / cm 3 ;

[0023] c) 0-80% by weight of at least one selected from a group consisting of a density equal to or less than 0.950 g / cm 3 The cyclic flavor component and density can be greater or less than 0.950g / cm 3 Materials that are non-cyclic flavoring ingredients;

[0024] wherein the sum of a), b) and c) is equal to 100%, wherein the weight ratio of the core material to the shell material is in the range of 50:1 to 1:1; and wherein the starting material comprises at least 50 wt%, preferably at least 60 wt% of one or more (meth)acrylates; wherein the dosage of the microcapsules in the liquid consumer product is in the range of 0.01 to 10 wt%, preferably 0.05 to 2.5 wt%, more preferably 0.1 to 1.25 wt% of the liquid product composition, and thus teaching the selection of density based on the shell wall material to encapsulate the selected flavor, wherein the shell material does not involve any poly((meth)acrylate-vinyl acetate copolymer) based on a selected polymerization process to produce thermally stable cross-linked microcapsules.

[0025] WO2014032920A1, EP2890486B1, CN104755162B, KR1020150052046, RU2015111081, BR112015004387, ID2016 / 05358, RU0002639909, JP2015535858, CA2882427, 1199 / CHENP / 2015; MX2015002649, JP2017105791; teach a microcapsule comprising a hydrophobic material core consisting of at least one fragrance and obtained by suspension polymerization of the following monomers Microcapsule shell: (a) one or more C1-C24 alkyl (meth)acrylates (monomer A), (b) one or more difunctional or polyfunctional monomers (monomer B) and (c) optionally, one or more other ethylenically unsaturated monomers (monomer C), wherein the shear rate for preparing the emulsion falls within the range of 150 to 500 rpm, the stirring time for preparing the emulsion falls within the range of 15 minutes to 180 minutes, and an anchor stirring blade or a MIG stirrer is used to prepare the emulsion, however, it does not teach any thermally stable microcapsules that can be obtained from the specific addition of vinyl acetate monomer by avoiding the shear rates mentioned in this prior art.

[0026] WO2017 / 004339, US20170002301, CA2989002, CN107835681, EP3316854B1, JP2018522976, PL3316854, IN201717045571, MX364218, JP2020073672; teach a consumer product comprising a composition, the composition comprising: an auxiliary material; a first population of microcapsules, the first population having a first median volume weighted particle size and comprising a first weight ratio of The invention relates to a composition comprising microcapsules comprising a partitioning modifier and a first fragrance oil; and a second population of microcapsules having a second median volume weighted particle size and comprising microcapsules comprising the partitioning modifier and the second fragrance oil in a second weight ratio; wherein the first weight ratio and the second weight ratio are different, and / or the first median volume weighted particle size and the second median volume weighted particle size are different; wherein the composition is a fabric and home care composition, and thus this prior art does not teach that thermally stable microcapsules can be obtained by avoiding a partitioning modifier and based on only one type of microcapsules having only one fragrance type.

[0027] Although microcapsules for encapsulating actives are known in the art, there is still a need to explore microcapsules with lipophilic materials as cores (such as fragrances) that are thermally stable and decompose above 250°C to adapt to high temperature applications including fabric steaming, hair straightening, painting, textile processing, and shoe insole making. Summary of the invention

[0028] It is therefore an object of the present invention to provide microcapsules with a lipophilic core which as microcapsules are thermally stable so that during their use at higher temperatures the shell does not break and thus prevents the loss of the lipophilic core and under any mechanical stress the shell breaks to release the core / benefit agent.

[0029] Another object of the present invention is to provide said microcapsules having a lipophilic core comprising a liquid active such as a fragrance.

[0030] Another object of the present invention is to provide the microcapsule synthesis method, which involves preheating / prepolymerization of monomers / shell materials in the oil phase, which is carried out under a preparation procedure comprising a single polymerization step; that is, all reactive monomers are copolymerized together in one step. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The olfactory performance of the microcapsule composition is shown.

[0032] Figure 2 TGA thermograms of the microcapsule compositions are shown.

[0033] Figure 3 Isothermal TGA thermograms of the microcapsule compositions are shown.

[0034] Figure 4 The olfactory performance of the microcapsule composition after steaming at 120°C for 3 minutes is shown.

[0035] The present invention relates to a microcapsule comprising a lipophilic core material and a microcapsule shell, wherein the microcapsule shell is formed by oil-in-water emulsion polymerization of a monomer mixture, more than 50% by weight of the monomer mixture is composed of monomers with a density higher than 1.05, and the monomer mixture comprises a) more than 30% by weight of one or more ethylenically unsaturated acid monomers, b) one or more monofunctional acrylate and / or methacrylate monomers, c) one or more multifunctional acrylate and / or methacrylate monomers, and d) vinyl acetate monomers, based on the total weight of the monomer mixture.

[0036] In one embodiment, the microcapsules are thermally stable at 250°C.

[0037] In one embodiment, the microcapsules are formaldehyde-free.

[0038] In one embodiment, the microcapsules are characterized in that the log P values ​​of all monomers contained in the monomer mixture are in the range of 0.5 to 4.0.

[0039] In one embodiment, the microcapsules are characterized in that the ethylenically unsaturated acid monomer is selected from acrylic acid, methacrylic acid, crotonic acid, 2-carboxyethyl acrylate, glutaconic acid, 3,3-dimethylacrylic acid, itaconic acid, maleic acid, fumaric acid or a mixture of two or more of said acids.

[0040] In one embodiment, the microcapsules are characterized in that the ethylenically unsaturated acid monomer is methacrylic acid.

[0041] In one embodiment, the microcapsules are characterized in that the concentration of the ethylenically unsaturated acid monomer in the monomer mixture is equal to or less than 45 weight percent based on the total weight of the monomer mixture.

[0042] In one embodiment, the microcapsules are characterized in that the concentration of the ethylenically unsaturated acid monomer in the monomer mixture is between 30% and 45% by weight, based on the total weight of the monomer mixture.

[0043] In one embodiment, the microcapsules are characterized in that the monofunctional acrylate and / or methacrylate monomers are chosen from polymerizable molecules having one ester function of the following formula or mixtures of two or more of said monomers:

[0044]

[0045] in

[0046] R1=H / CH3,

[0047] R2=-OH、-(CH2) n -OH, O-CH3, -O-(CH2) m -OH, -O-(CH2) n –CH3,

[0048] -(O-CH2-CH2) n -OH, -(O-CH2-CH2-CH2) n -OH, -(O-CH2-CH2) n -O-CH3, -(O-CH2-CH2) n -O-CH2-CH3, -(O-CH2-CH2-CH2)nO-CH2-CH3, -(O-CH2-CH2-CH2)nO-CH3, -(O-CH2-CHR3) n -CH3

[0049] n=1 to 10, m=2 to 10, and R3=methyl or ethyl.

[0050] In one embodiment, the microcapsules are characterized in that the monofunctional acrylate and / or methacrylate monomers are selected from 2-hydroxyethyl methacrylate, poly(ethylene glycol) methacrylate, poly(propylene glycol) methacrylate, 4-hydroxybutyl acrylate, hydroxybutyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate or a mixture of two or more of said monomers.

[0051] In one embodiment, the microcapsules are characterized in that the monofunctional acrylate and / or methacrylate monomer is hydroxyethyl methacrylate.

[0052] In one embodiment, the microcapsules are characterized by a concentration of monofunctional acrylate and / or methacrylate monomers ranging from 5 to 50 weight percent based on the total weight of the monomer mixture.

[0053] In one embodiment, the microcapsules are characterized in that the multifunctional acrylate and / or methacrylate monomers are selected from polymerizable molecules having more than one ester functional group.

[0054] In one embodiment, the microcapsules are characterized in that the one or more multifunctional acrylate and / or methacrylate monomers are a mixture of two or more of said monomers,

[0055] In one embodiment, the microcapsules are characterized in that the multifunctional acrylate and / or methacrylate monomers are selected from ethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, glycerol diacrylate, glycerol dimethacrylate, 1,10-decanediol dimethacrylate, bis[2-(methacryloyloxy)ethyl]phosphate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, or a mixture of two or more of said monomers.

[0056] In one embodiment, the microcapsules are characterized in that the multifunctional acrylate and / or methacrylate monomer is a mixture of two or more of said monomers, each of said monomers accounting for less than 30% by weight based on the total weight of the monomer mixture.

[0057] In one embodiment, the microcapsules are characterized in that the total concentration of multifunctional acrylate and / or methacrylate monomers in the monomer mixture is less than 60 weight percent based on the total weight of the monomer mixture.

[0058] In one embodiment, the microcapsules are characterized in that the concentration of the multifunctional acrylate and / or methacrylate monomer in the monomer mixture is between 20 and 50 weight percent based on the total weight of the monomer mixture.

[0059] In one embodiment, the microcapsules are characterized in that the concentration of the vinyl acetate monomer in the monomer mixture is between 0.05 and 15 weight percent based on the total weight of the monomer mixture.

[0060] In one embodiment, the microcapsules are characterized by a) ethylenically unsaturated acid monomers, b) monofunctional acrylate and / or methacrylate monomers, c) multifunctional acrylate and / or methacrylate monomers, and d) vinyl acetate monomers in a concentration of at least 95 weight percent based on the total weight of the monomer mixture.

[0061] In one embodiment, the microcapsules are characterized by a) ethylenically unsaturated acid monomers, b) monofunctional acrylate and / or methacrylate monomers, c) multifunctional acrylate and / or methacrylate monomers, and d) vinyl acetate monomers, the concentration of [a) + b) + c) + d)] being 100% by weight based on the total weight of the monomer mixture.

[0062] In one embodiment, the microcapsules are characterized in that the microcapsules have a particle size range of Dv(90) values ​​of 8 to 35 microns.

[0063] In one embodiment, the microcapsules are characterized in that the lipophilic core material of the microcapsules has a viscosity equal to or less than 0.95 g / cm at 25°C. 3 The density of the combined log P is between 2.5 and 6.0.

[0064] In one embodiment, the microcapsules are characterized in that the lipophilic core material of the microcapsules comprises at least 95% by weight, preferably 100% by weight, based on the total weight of the lipophilic core material, of one or more of the following ingredients: fragrances, profragrances, emollient oils, essential oils, hair-benefitting agents, skin-benefitting agents, conditioning agent actives, cosmetic care actives, personal care actives, UV absorbers, vitamins, antioxidants, antimicrobial agents, antiviral agents, flavoring agents, anti-odor agents, pharmaceutical agents, dyes, printing inks, insecticides, microbicides, agrochemicals, coating materials, anti-aging actives.

[0065] In one embodiment, the microcapsules are characterized in that the lipophilic core material of the microcapsules comprises one or more of the following ingredients: fragrance, essential oil, hair benefit agent, skin benefit agent, antimicrobial agent, antiviral agent, anti-odor agent.

[0066] In one embodiment, the microcapsules are characterized by a lipophilic core material weight divided by the microcapsule shell weight of between 15 and 0.2, such as between 15 and 0.33, such as between 15 and 0.4.

[0067] An aqueous microcapsule composition comprising water and the microcapsule according to claim 1, wherein the water accounts for 35 to 82 weight % of the total weight of the aqueous microcapsule composition.

[0068] The present invention also relates to an aqueous microcapsule composition comprising a microcapsule comprising a lipophilic core material and a microcapsule shell.

[0069] wherein the microcapsule shell is formed by oil-in-water emulsion polymerization of a monomer mixture, more than 50% by weight of the monomer mixture consists of monomers having a density greater than 1.05, the monomer mixture comprising a) more than 30% by weight of one or more ethylenically unsaturated acid monomers, b) one or more monofunctional acrylate and / or methacrylate monomers, c) one or more multifunctional acrylate and / or methacrylate monomers, and d) vinyl acetate monomers, and

[0070] The lipophilic core material accounts for 15 to 45 weight % of the total weight of the aqueous microcapsule composition.

[0071] In one embodiment, the aqueous microcapsule composition is characterized in that it comprises one or more emulsifiers, wherein the emulsifiers account for 0.05 to 5 weight percent of the total weight of the aqueous microcapsule composition.

[0072] In one embodiment, the aqueous microcapsule composition is characterized in that the weight of water, microcapsules, and emulsifiers constitutes at least 90 weight percent of the total weight of the aqueous microcapsule composition.

[0073] The present invention also relates to a method for preparing an aqueous microcapsule composition, the composition comprising microcapsules comprising a lipophilic core material and a microcapsule shell.

[0074] wherein the microcapsule shell is formed by oil-in-water emulsion polymerization of a monomer mixture, more than 50% by weight of the monomer mixture consists of monomers having a density greater than 1.05, the monomer mixture comprising a) more than 30% by weight of one or more ethylenically unsaturated acid monomers, b) one or more monofunctional acrylate and / or methacrylate monomers, c) one or more multifunctional acrylate and / or methacrylate monomers, and d) vinyl acetate monomers, and

[0075] The lipophilic core material accounts for 15 to 45% by weight of the total weight of the aqueous microcapsule composition.

[0076] The method comprises the following steps:

[0077] 1. dissolving the monomer mixture together with the initiator in an oil phase containing the lipophilic core material and heating the oil phase to form a prepolymer,

[0078] 2. Dissolve the emulsifier in the water phase,

[0079] 3. Emulsify the oil phase of step 1 into the water phase of step 2, and

[0080] 4. Heat the emulsion from step 3 to form a suspension of core-shell microcapsules in water.

[0081] In one embodiment, the process for preparing an aqueous microcapsule composition is characterized in that the emulsification step of the core phase in the aqueous phase is obtained by stirring with a propeller stirrer at 500-1500 rpm for up to 12 minutes.

[0082] The present invention also relates to a non-therapeutic method of use of a microcapsule or aqueous microcapsule composition as claimed, comprising using said microcapsule to deliver a lipophilic core material of an industrial composition related to home care products, personal care products, textile products, printing and coating application products, pharmaceutical formulation products, consumer product products and agro-industrial formulation products.

[0083] In one embodiment, the non-therapeutic method of use is characterized in that the mechanical stress and temperature conditions at which the microcapsules are exposed are sufficient to break the microcapsule shell and deliver the lipophilic core material.

[0084] In one embodiment, the non-therapeutic method of use according to the invention is suitable for fabric steaming, hair straightening, painting, textile processing and insole making. DETAILED DESCRIPTION

[0085] The following description relates to specific embodiments of the present invention.

[0086] As described above, the present invention provides formaldehyde-free microcapsules comprising a polymer shell and a lipophilic active core, which have high thermal stability and are destroyed at a temperature above 250°C, and are suitable for applications at high temperatures, such as but not limited to fabric steaming, hair straightening, painting, textile processing, and insole making, wherein the polymer shell comprises a cross-linked (meth)acrylic acid-vinyl acetate copolymer.

[0087] For a person skilled in the art, a microcapsule comprising a lipophilic core material and a microcapsule shell which is thermally stable at 250°C means that the microcapsule shell is not destroyed at 250°C.

[0088] Any suitable measurement method may advantageously be used to measure the thermally stable at 250°C property.

[0089] For example, it can be advantageously measured by taking a sample of a microcapsule slurry intended for commercialization, such as the microcapsule slurry sample obtained at the end of Example 1 below; examining the microcapsule slurry sample using a thermogravimetric analyzer (TGA); subjecting it to gradually increasing temperatures, for example from ambient temperature up to 250° C. at increments of 30° C. per minute; and measuring the lipophilic core material weight loss. When the lipophilic core material weight loss is less than 7.5 wt. %, preferably less than 5 wt. %, based on the total weight of the encapsulated core material, it can be concluded that the microcapsules are thermally stable at 250° C.

[0090] For example, if the ambient temperature is 20°C, the duration of the temperature increase to 250°C to which the sample is subjected and the corresponding TGA observation will take approximately 7 minutes and 40 seconds.

[0091] Therefore, when the microcapsules were examined using a thermogravimetric analyzer (TGA), the shell encapsulating the microcapsules of the lipophilic core material was destroyed only at temperatures above 250°C.

[0092] Advantageously, another characteristic of the polymer shell of the encapsulated lipophilic core material microcapsules of the present invention is that the shell can prevent the lipophilic core material from being lost due to leakage when the microcapsules are exposed to 120° C. for a long time (e.g., more than 30 minutes). This further demonstrates the thermal stability of the microcapsules, which enables the microcapsules to maintain their integrity for a longer period of time in applications requiring long-term heat exposure.

[0093] The shell of the present invention comprises a polymer made of building blocks (which are essentially polymerizable molecules), more than 50% of which have a molecular weight of 1.05 g / cm at 25°C. 3 or higher density and having a log P value ranging between 0.5 and 4.0, having an ester functional group and an ester-forming functional group.

[0094] By definition, Log P refers to the octanol / water partition coefficient (P) of any individual ingredient, which is the ratio between the equilibrium concentrations of the individual ingredient in octanol and water. The partition coefficient of an ingredient is given as the logarithm to the base 10, Log P. The individual Log P values ​​here are usually provided by the raw material supplier. The combined Log P value of a fragrance is determined by averaging the individual Log P values ​​based on weight %.

[0095] By definition, the density here refers to the individual densities of all materials used and the value is expressed in g / cm2 at 25°C. 3These values ​​are collected from Sigma Aldrich, India (https: / / www.sigmaaldrich.com / IN / en) and / or The Good Scents Company Information System (http: / / www.thegoodscentscompany.com / ). The density of the fragrances in Examples 1-3 was measured using a pycnometer at 25°C using ATSM D 369 method.

[0096] A polymerizable molecule in the present invention refers to an organic molecule having one or more ethylenically unsaturated moieties.

[0097] By definition, the aqueous microcapsule composition or slurry in the present invention refers to an aqueous medium containing dispersed microcapsules in the presence of an emulsifier, wherein the microcapsules contain a lipophilic core (e.g., a fragrance) and a polymer shell formed by polymerization of ethylenically unsaturated molecules initiated by an oil-soluble (thermal) initiator at elevated temperature. The final product of Example 1 is referred to as an aqueous microcapsule composition or slurry according to the present invention.

[0098] For example, as shown in the previous Example 1, the emulsifier is present in the final slurry; most of the initiator generates lauric acid radicals, which then begin to form the crosslinked shell polymer, and the remaining lauric acid radicals form lauric acid and thereby remain dissolved / entrapped in the core.

[0099] By definition, a polymerizable molecule having an ester functionality is referred to as an ethylenically unsaturated molecule having at least one ester moiety.

[0100] By definition, a polymerizable molecule having an ester-forming functional group is further specified as an ethylenically unsaturated molecule having at least one free acid functional group that can be chemically converted into an ester moiety. Examples of such polymerizable molecules having one free acid functional group are, but are not limited to, acrylic acid, methacrylic acid, crotonic acid, 2-carboxyethyl acrylate, glutaconic acid, 3,3-dimethylacrylic acid, itaconic acid, maleic acid, fumaric acid, and the like.

[0101] The building blocks of the present invention comprise (a) more than 30 wt% of one or more polymerizable molecules having one free acid functional group, based on the total weight of the shell.

[0102] The building blocks in the present application comprise (b) one or more polymerizable molecules having an ester functional group of the following formula:

[0103]

[0104] Where R1=H / CH3,

[0105] R2=-OH、-(CH2) n -OH, O-CH3, -O-(CH2) m -OH, -O-(CH2) n –CH3,

[0106] -(O-CH2-CH2) n -OH, -(O-CH2-CH2-CH2) n -OH, -(O-CH2-CH2) n -O-CH3, -(O-CH2-CH2) n -O-CH2-CH3, -(O-CH2-CH2-CH2)nO-CH2-CH3, -(O-CH2-CH2-CH2)nO-CH3, -(O-CH2-CHR3) n -CH3

[0107] n=1 to 10, m=2 to 10,

[0108] R3 = methyl or ethyl.

[0109] Examples of polymerizable molecules having an ester functional group of the above molecular formula include, but are not limited to, 2-hydroxyethyl methacrylate, poly(ethylene glycol) methacrylate, poly(propylene glycol) methacrylate, 4-hydroxybutyl acrylate, hydroxybutyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate, and the like.

[0110] The building blocks of the present invention comprise (c) less than 60 wt % of the shell of two or more polymerizable molecules having more than one ester functional group, wherein each molecule in the building block composition is less than 30 wt % of the shell.

[0111] Examples of polymerizable molecules having more than one ester functional group are, but are not limited to, ethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, glycerol diacrylate, glycerol dimethacrylate, 1,10-decanediol dimethacrylate, bis[2-(methacryloyloxy)ethyl]phosphate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, and the like.

[0112] The building blocks in the present application comprise (d) vinyl acetate.

[0113] The total weight % of (a), (b), (c) and (d) is 100% to form a shell according to the present invention.

[0114] The microcapsules of the present invention are obtained by a three-step process comprising i) preheating / prepolymerization of building blocks (i.e. polymerizable molecules) in a lipophilic active core phase in the presence of an oil-soluble initiator, ii) emulsifying the core in an aqueous phase, and iii) heating the emulsion at elevated temperature to form a crosslinked shell polymer.

[0115] The detailed method for preparing microcapsules according to the present invention may advantageously include the following steps:

[0116] 1. a) dissolving the polymerizable molecules (i.e. building blocks) and the initiator in the lipophilic core, i.e. oil phase; b) heating the oil phase at 40-55° C. under nitrogen while stirring at 100-200 rpm for 15-45 minutes to form a prepolymer;

[0117] 2. Dissolve the emulsifier in the water phase;

[0118] 3. Emulsify the oil phase of step 1 into the water phase of step 2 by stirring with a propeller stirrer at 500-1500 rpm for up to 12 minutes;

[0119] 4. Under nitrogen, the emulsion was heated first at 40-60° C. for 15 to 45 minutes at 100-400 rpm, and then at 65-85° C. for 4-6 hours;

[0120] 5. Quench the unreacted monomers by adding aqueous persulfate solution at 65-85°C.

[0121] The core of the microcapsule of the present invention comprises a lipophilic active substance having a viscosity equal to or less than 0.95 g / cm 3 The core accounts for 15-45% by weight of the aqueous microcapsule composition. The core:shell ratio varies from 15:1 to 1:5; for example, from 15:1 to 1:3 or from 15:1 to 2:5. The total solids of the aqueous microcapsule composition range from 18-65% by weight, and the composition includes a lipophilic core-polymer shell microcapsule, an emulsifier, and other ingredients.

[0122] The lipophilic core mainly includes but is not limited to fragrances, fragrance precursors, emollient oils, essential oils, hair and skin benefit agents, conditioner actives, cosmetic and personal care actives, UV absorbers, vitamins and antioxidants, antimicrobial and antiviral agents, flavoring agents, deodorants, pharmaceuticals, dyes and printing inks, pesticides and microbicides, agrochemicals, coating materials, anti-aging actives, etc.

[0123] Emulsifiers used in the present invention are basically anionic, nonionic and cationic small molecules, oligomers and polymers. Examples of anionic emulsifiers are salts of: alkyl sulfates, alkyl ether sulfates, alkyl carboxylates, alkyl succinamates, alkyl sulfosuccinates, alkyl sulfates such as sodium lauryl sulfate, alkyl sarcosinates, alkyl or alkyl ether or alkyl aryl ether phosphates, ammonium stearate, sodium stearate or potassium stearate, ammonium oleate, sodium oleate or potassium oleate or ammonium palmitate, sodium palmitate or potassium palmitate, alkyl aryl sulfonates such as sodium dodecylbenzene sulfonate, dialkyl sodium sulfosuccinate, dioctyl sulfosuccinate, dilauryl sodium sulfosuccinate. The nonionic emulsifier used in the present invention is but not limited to acetylated monoglyceride, lactylated monoglyceride, phosphorylated or sulfated tristyrylphenol polyoxyethylene ether, secondary alcohol polyoxyethylene ether, oligoethylene glycol esters of fatty acids, lactylated propylene glycol monoglyceride, sorbitan ester, sorbitan-polyoxyethylene monoglyceride, polyglycerol ester, diacetyl tartaric acid ester of monoglyceride, and succinylated ester of monoglyceride. The polymer emulsifier used in the present application is a nonionic surfactant, such as a diblock copolymer of polyethylene oxide and polyethylene or polypropylene oxide, sodium polystyrene sulfonate, isobutylene-maleic anhydride copolymer, gum arabic, sodium alginate, carboxymethyl cellulose, cellulose sulfate and pectin, poly (styrene sulfonate), gum arabic, carrageenan, sodium alginate, pectic acid, tragacanth and agar; carboxymethyl starch, phosphorylated starch, lignin sulfonic acid; polyacrylic acid, polymethacrylic acid, butyl acrylate copolymer or crotonic acid homopolymer and copolymer, vinylbenzenesulfonic acid or 2-acrylamide-2-methylpropanesulfonic acid homopolymer and copolymer, and partial amides or partial esters of such polymers and copolymers, carboxyl-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol and phosphoric acid-modified polyvinyl alcohol and mixtures thereof.

[0124] The amount of emulsifier ranges between 0.05 and 5% by weight of the microcapsule composition described herein.

[0125] In one non-limiting embodiment, the initiator used to prepare the microcapsules and dissolved in the lipophilic core is a thermal initiator selected from dibenzoyl peroxide, dicaprylyl peroxide, dilauroyl peroxide, didecanoyl peroxide, t-butyl peracetate, t-butyl perlaurate, t-butyl perbenzoate, di(hexadecyl) peroxydicarbonate, di(4-t-butylcyclohexyl) peroxydicarbonate, t-butyl hydroperoxide, cumene hydroperoxide, ethyl cumene peroxide, diisopropyl hydroxydicarboxylate, and combinations thereof.

[0126] The initiator used in this application is 0.2 to 5% by weight of the microcapsule composition.

[0127] In a non-limiting embodiment, a quencher is used during the preparation of the microcapsules. For example, 0.02 to 0.5 wt % of ammonium peroxodisulfate or potassium peroxodisulfate in the form of an aqueous solution of the microcapsule composition is used as a quencher in the present invention. Potassium peroxodisulfate is also known as potassium persulfate (K2S2O8). It is commonly used as an oxidant and polymerization initiator in organic synthesis.

[0128] The particle size of the microcapsule composition proposed in the present invention ranges between Dv(90) values ​​of 8-35 um as measured using a Malvern Mastersizer 3000.

[0129] Application products:

[0130] The microcapsule composition according to the present invention is suitable for use in, but not limited to, household and personal care products, textile products, printing and coating applications, pharmaceutical formulations, consumer products, and agro-industrial formulation products.

[0131] Non-limiting examples of household care products containing microcapsules according to the present invention can be divided into the following: 1. Air care products, 2. Household cleaners, 3. Dishwashing products, 4. Laundry / fabric care products. Examples of air care products are roughly i) aqueous air freshener liquids, gels, sprays, interior decoration fresheners and sprays and liquids for metered dosing products, ii) tablets, pills, blocks, pastes, etc. 2. Household cleaners with microcapsule compositions according to the present invention are multi-surface cleaners, carpet cleaners, hard surface cleaners, etc. 3. According to the present application, dishwashing products are liquid dishwashing detergents, dishwashing tablets and blocks, etc. 4. According to one embodiment of the present application, laundry / fabric care products are mainly liquid and solid laundry detergents, fabric conditioners, fabric refreshers, fabric stiffeners, stain removal products, fabric refresher sprays, solid fabric softener and freshener products and cone-shaped fabric fresheners, etc.

[0132] Examples of personal care products having as active the lipophilic core in the microcapsules according to the invention are leave-on and rinse-off hair and skin care compositions such as shampoos, conditioners, depilatories, hair styling gels, hair dyes, antiperspirants / deodorants, aqua mists, as well as spray-on and roll-on products, shower gels, shower gels, hand soaps, soaps, body lotions, face cleansers, face masks, face creams, face serums, sunscreens, etc. Examples of cosmetic products comprising microcapsules are such as, but not limited to, lip gloss preparations, foundations, primers, eye shadows, etc.

[0133] Non-limiting examples of pharmaceutical formulations are primarily dermatological products such as ointments, sprays, creams, lotions, gels and transdermal patches and the like.

[0134] Microcapsules with fragrance, antimicrobial and antiviral agents according to this report are used in textile / fabric manufacturing to combat bad odors and microorganisms. In addition, microcapsules are also used in diapers and sanitary napkins.

[0135] The printing formulation with microcapsules according to the present application is used for inkjet printing, spraying, flexographic printing, roller and cylinder printing, stencil printing, digital printing, etc., wherein the lipophilic core of the microcapsule contains dyes and printing inks, fragrances, fragrance precursors, antimicrobial and antiviral agents, anti-odor agents, etc. According to one embodiment of the present application, the coating material used for encapsulation is selected from non-limiting examples, wherein the core contains an oil-soluble material having film-forming properties on the skin and hair, such as vinyl pyrrolidone / hexadecene and vinyl pyrrolidone / eicosene copolymers, triacontanyl polyvinyl pyrrolidone, etc.

[0136] Non-limiting examples of consumer products comprising microcapsules according to the invention are paints, polishes for hard surfaces, insoles and the like.

[0137] Example

[0138] Example 1. Preparation of microcapsule composition according to the present invention

[0139] Raw materials for preparing aqueous microcapsule slurry

[0140] Composition of oil phase 1:

[0141] Fragrance: 30g (lipophilic core)

[0142] 1a. Composition of fragrance:

[0143]

[0144]

[0145] The density of the fragrance at 25°C is 0.8446 g / cm 3 , and the combined (average) Log P is 3.61

[0146] 1b. Methacrylic acid: 2.2 g

[0147] 1c. 2-Hydroxyethyl methacrylate: 0.65 g

[0148] 1d. Ethylene glycol dimethacrylate: 1.05 g

[0149] 1e. Pentaerythritol tetraacrylate: 1.25g

[0150] 1f. Vinyl acetate: 0.61g

[0151] 1g. Dilauroyl peroxide: 1.2g

[0152] Composition of aqueous phase 2:

[0153] Water: 57.8g

[0154] 25% sodium dodecyl sulfate aqueous solution: 8g

[0155] Composition of aqueous phase 3:

[0156] 0.13g potassium peroxodisulfate in 10g water

[0157] Preparation method of microcapsules

[0158] Table 1. Detailed preparation method of microcapsule formulation according to the present invention

[0159]

[0160]

[0161] Comparative Example 2-3. Preparation of a microcapsule composition having a fragrance of the present invention according to the prior art so as to enable comparison of olfactory properties

[0162] Table 2. Comparative Examples 2-3 of Microcapsule Compositions According to Prior Art

[0163]

[0164]

[0165] Characterization of Microcapsule Compositions:

[0166] Particle size analysis:

[0167] The particle size was analyzed using a Mastersizer 3000 with a Hydro MV wet dispersion unit. Diluted aqueous solutions (0.5 wt%) of the microcapsule compositions of Example 1 and Comparative Examples 2-3 were measured and the data were analyzed using the Mie scattering model and are presented in Table 3.

[0168] Table 3. Dv(90) values ​​of the microcapsule compositions of Example 1 and Comparative Examples 2-3

[0169] Microcapsule composition Dv(90)(in um) Example 1 25.2 Comparative Example 2 28.8 Comparative Example 3 9.05

[0170] Analysis of free oil percentage after microencapsulation:

[0171] 1 g of the microcapsule composition slurry of Example 1 was mixed with 5 g of hexane in a sealed tube. The mixture was shaken in an orbital shaker at 300 rpm for 15 minutes. The sample was then allowed to stand for 10 minutes. The supernatant was passed through a 0.45 um filter and subjected to GC analysis. The remaining fragrance was quantified using an Agilent INTOVU9000G3950A GC with column part number: 19091S-433UI-INT HP-5MS UI 30m, 0.25 um. There was almost no free oil remaining from the microcapsule composition of Example 1 (0.13% of the total core).

[0172] Table 4: Free oil analysis of the microcapsule compositions of Example 1 and Comparative Examples 2-3

[0173] Microcapsule composition Free oil percentage of microcapsule composition Example 1 0.13 Comparative Example 2 0.45 Comparative Example 3 2.25

[0174] This is a good indication of the superior encapsulation properties of our microcapsules, as it becomes increasingly important to develop consumer products that will release the active core material on demand without facing the potential drawbacks that may arise from having too much lipophilic material on the outside of the microcapsules and inside the consumer product (before use). This is beneficial for the end use of the microcapsules in consumer products, as it ensures that the microcapsules have better post-rubbing properties (due to the effective encapsulation of the core fragrance) via the application of the consumer product (e.g. when treating fabrics with a fabric softener containing the microcapsules). The microcapsules according to the present invention have excellent thermal stability, allowing the microcapsules to be used at higher temperatures, for example when steaming fabrics treated with a product containing the microcapsules.

[0175] Olfactory performance of the fragrance core microcapsules of Example 1 and Comparative Examples 2-3.

[0176] According to the supplier's (Stepan Company, Northbrook, IL 60062, United States) recommendations, a conventional fabric softening formulation was prepared in water with 5% Stepantex SP-90 as a softening active and 0.1% sodium benzoate as a preservative. Individual fabric softening formulations were prepared using the individual microcapsule compositions of Example 1 and Comparative Examples 2-3, while maintaining the encapsulated fragrance core 0.3% by weight in the final softener formulation. Cotton fabrics were washed and treated with the softener formulation (dosage of 5 g of fabric softener formulation in 1 liter of water) and rinsed for 10 minutes, and then the fabrics were left to dry under ambient conditions. For the pre- and post-rubbing stages of the fabrics, the olfactory characteristics of the dried fabrics were recorded by trained panelists. Figure 1The average results for fragrance intensity are presented in . The intensity ratings range from 1 to 5, with 1 being the weakest and 5 being the strongest on an ascending scale. Compared to the prior art microcapsule compositions, Example 1 exhibited the highest post-rub intensity at the same core (fragrance) loading level.

[0177] Thermal stability of microcapsule compositions

[0178] A. Thermal stability of microcapsules

[0179] Thermal stability of microcapsules: The microcapsule compositions were analyzed using a Perkin TGA 4000 instrument, where the slurry samples were gradually heated from 30°C to 500°C at 30°C / min and then gradually heated at 50°C / min up to 800°C under a nitrogen atmosphere. The major weight loss in the thermogram is associated with the relevant phase transitions in the microcapsule composition. Figure 2 In the thermogram of Example 1, a sharp drop in weight is noted around 150–170°C and this is mainly related to the loss of water in the composition. The next weight loss is related to the destruction of the shell and the evaporation / loss of the core (fragrance). The microcapsule composition of Example 1 shows excellent stability around 250°C and shows minimal weight loss. Therefore, it clearly demonstrates the high thermal stability of the microcapsule composition of the present invention.

[0180] B. Core loss at high temperature for extended periods of time

[0181] The core loss of Example 1 and Comparative Example 3 at high temperature for an extended period of time (30 minutes) was studied. This was to confirm the leakage of the core at high temperature. Preventing core loss at high temperature is a necessary condition for the application of microcapsules at high temperatures. Due to the low performance of Example 2 (such as Figure 1 The sample was gradually heated from 30°C to 120°C at 3°C / min and then kept at 120°C for 30 minutes. Under nitrogen atmosphere, the sample was further gradually heated to 800°C at 50°C / min. The weight loss of the microcapsule composition over time was monitored at 120°C and is presented in Figure 3 In. From Figure 3 It can be seen that the microcapsule composition of Example 1 has no weight loss within 30-60 minutes when the microcapsules are exposed to 120°C. In the case of Example 3, however, there is a significant core loss (nearly 10% weight loss) at high temperatures. Therefore, the shell composition of the present invention does not cause core (fragrance) loss. This also means the importance of the present invention for applications at higher temperatures.

[0182] C. High temperature applications

[0183] Steaming of fabrics to which microcapsules containing fabric softeners were applied: cotton fabrics washed and treated with the microcapsule composition of Example 1 of the present invention containing fabric softeners as described in detail above were subjected to hot steam for 3 minutes. The fabrics were then evaluated before and after rubbing after the fabrics were cooled to room temperature. As previously described, the strength rating ranged from 1-5, with 1 being the weakest and 5 being the strongest in an ascending scale. It was observed that after steaming, the effect on the strength of the microcapsules was almost negligible based on the average post-rubbing values.

Claims

1. A microcapsule comprising a lipophilic core material and a microcapsule shell, wherein the microcapsule shell is formed by oil-in-water emulsion polymerization of a monomer mixture, more than 50% by weight of the monomer mixture being composed of monomers having a density greater than 1.05, the monomer mixture comprising a) more than 30% by weight of one or more ethylenically unsaturated acid monomers, b) one or more monofunctional acrylate and / or methacrylate monomers, c) one or more multifunctional acrylate and / or methacrylate monomers, and d) vinyl acetate monomers, based on the total weight of the monomer mixture.

2. The microcapsule according to claim 1, which is thermally stable at 250°C. The microcapsule according to claim 1 , which does not contain formaldehyde.

4. The microcapsule according to claim 1, wherein the log P value of all monomers contained in the monomer mixture ranges from 0.5 to 4.

0.

5. The microcapsule according to claim 1, wherein the ethylenically unsaturated acid monomer is selected from acrylic acid, methacrylic acid, crotonic acid, 2-carboxyethyl acrylate, glutaconic acid, 3,3-dimethylacrylic acid, itaconic acid, maleic acid, fumaric acid or a mixture of two or more of the acids.

6. The microcapsule of claim 1, wherein the ethylenically unsaturated acid monomer is methacrylic acid.

7. The microcapsule according to any one of claims 5 or 6, wherein the concentration of the ethylenically unsaturated acid monomer in the monomer mixture is equal to or less than 45 wt% based on the total weight of the monomer mixture.

8. The microcapsule according to any one of claims 5 or 6, wherein the concentration of the ethylenically unsaturated acid monomer in the monomer mixture is between 30 and 45 weight percent based on the total weight of the monomer mixture.

9. The microcapsule according to claim 1, wherein the monofunctional acrylate and / or methacrylate monomer is selected from polymerizable molecules having one ester functional group or a mixture of two or more of the monomers of the following formula: in R1=H / CH3, R2=-OH、-(CH2) n -OH、O-CH3、-O-(CH2) m -OH、 -O-(CH2) n –CH3、-(O-CH2-CH2) n -OH、-(O-CH2-CH2-CH2) n -OH、 -(O-CH2-CH2) n -O-CH3、-(O-CH2-CH2) n -O-CH2-CH 3、 -(O-CH2-CH2-CH2)nO-CH2-CH3, -(O-CH2-CH2-CH2)nO-CH3, <h2 style=";text-align:left;direction:ltr">-(O-CH2-CHR3)<h2 style=";text-align:left;direction:ltr"> n <h2 style=";text-align:left;direction:ltr"> -CH3 n=1 to 10, m=2 to 10, and R3=methyl or ethyl.

10. The microcapsule according to claim 1, wherein the monofunctional acrylate and / or methacrylate monomer is selected from 2-hydroxyethyl methacrylate, poly(ethylene glycol) methacrylate, poly(propylene glycol) methacrylate, 4-hydroxybutyl acrylate, hydroxybutyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate or a mixture of two or more of said monomers.

11. The microcapsule according to claim 1, wherein the monofunctional acrylate and / or methacrylate monomer is hydroxyethyl methacrylate.

12. The microcapsule according to any one of claims 9 to 11, wherein the concentration of the monofunctional acrylate and / or methacrylate monomer is between 5 and 50 wt% based on the total weight of the monomer mixture.

13. The microcapsule according to claim 1, wherein the multifunctional acrylate and / or methacrylate monomers are selected from polymerizable molecules having more than one ester functional group.

14. The microcapsule according to claim 1, wherein the multifunctional acrylate and / or methacrylate monomer is selected from ethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, glycerol diacrylate, glycerol dimethacrylate, 1,10-decanediol dimethacrylate, bis[2-(methacryloyloxy)ethyl]phosphate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate or a mixture of two or more of the monomers.

15. The microcapsule according to claim 14, wherein the multifunctional acrylate and / or methacrylate monomer is a mixture of two or more of the monomers, each of the monomers accounting for less than 30 wt% based on the total weight of the monomer mixture.

16. The microcapsule according to any one of claims 13 to 15, wherein the total concentration of multifunctional acrylate and / or methacrylate monomers in the monomer mixture is less than 60 wt% based on the total weight of the monomer mixture.

17. The microcapsule according to any one of claims 13 to 15, wherein the concentration of the multifunctional acrylate and / or methacrylate monomer in the monomer mixture is between 20 and 50 wt% based on the total weight of the monomer mixture.

18. The microcapsule of claim 1, wherein the concentration of the vinyl acetate monomer in the monomer mixture is between 0.05 and 15 weight percent based on the total weight of the monomer mixture.

19. The microcapsule of claim 1, wherein the concentration of a) ethylenically unsaturated acid monomers, b) monofunctional acrylate and / or methacrylate monomers, c) multifunctional acrylate and / or methacrylate monomers, and d) vinyl acetate monomers is at least 95 weight percent based on the total weight of the monomer mixture.

20. The microcapsule according to claim 19, wherein the concentration of [a) + b) + c) + d)] is 100 wt% based on the total weight of the monomer mixture.

21. The microcapsule of claim 1, wherein the microcapsule has a particle size ranging from 8 to 35 microns in Dv(90) value.

22. The microcapsule according to claim 1, wherein the lipophilic core material of the microcapsule has a viscosity equal to or less than 0.95 g / cm at 25°C. 3 The density of the combined log P is between 2.5 and 6.

0.

23. The microcapsule of claim 1, wherein the lipophilic core material of the microcapsule comprises at least 95 wt % of one or more of the following ingredients, based on the total weight of the lipophilic core material: fragrances, fragrance precursors, emollient oils, essential oils, hair benefit agents, skin benefit agents, conditioning agent actives, cosmetic care actives, personal care actives, UV absorbers, vitamins, antioxidants, antimicrobial agents, antiviral agents, flavoring agents, anti-odor agents, pharmaceutical agents, dyes, printing inks, pesticides, microbicides, agrochemicals, coating materials, anti-aging actives.

24. The microcapsule of claim 23, wherein the lipophilic core material of the microcapsule comprises one or more of the following ingredients: fragrance, essential oil, hair benefit agent, skin benefit agent, antimicrobial agent, antiviral agent, anti-odor agent.

25. The microcapsule of claim 1, wherein the weight of the lipophilic core material divided by the weight of the microcapsule shell is between 15 and 0.

33.

26. An aqueous microcapsule composition comprising water and the microcapsule according to claim 1, wherein the water accounts for 35 to 82 weight % of the total weight of the aqueous microcapsule composition.

27. The aqueous microcapsule composition according to claim 26, wherein the lipophilic core material accounts for 15 to 45 weight % of the total weight of the aqueous microcapsule composition.

28. The aqueous microcapsule composition according to claim 26, comprising one or more emulsifiers, wherein the emulsifiers account for 0.05 to 5 weight percent of the total weight of the aqueous microcapsule composition.

29. The aqueous microcapsule composition of claim 28, wherein the weight of water, microcapsules and emulsifier accounts for at least 90 weight percent of the total weight of the aqueous microcapsule composition.

30. A method for preparing an aqueous microcapsule composition as claimed in any one of claims 26 to 29, comprising the following steps: (1) dissolving the monomer mixture together with an initiator in an oil phase containing the lipophilic core material and heating the oil phase to form a prepolymer, (2) dissolving the emulsifier in the water phase, (3) emulsifying the oil phase of step 1 into the water phase of step 2, and (4) Heating the emulsion from step 3 to form a suspension of core-shell microcapsules in water.

31. The method according to claim 30, wherein the emulsification step of the core phase in the aqueous phase is obtained by stirring with a propeller stirrer at 500-1500 rpm for up to 12 minutes.

32. A method of non-therapeutic use of a microcapsule according to any one of claims 1 to 25 or an aqueous microcapsule composition according to any one of claims 26 to 29, comprising using the microcapsule to deliver a lipophilic core material of an industrial composition related to home care products, personal care products, textile products, printing and coating application products, pharmaceutical formulation products, consumer product products and agricultural industrial formulation products.

33. The non-therapeutic method of use according to the preceding claim, wherein the mechanical stress and temperature conditions to which the microcapsules are exposed are sufficient to destroy the microcapsule shell and deliver the lipophilic core material.

34. Non-therapeutic use according to the preceding claims for fabric steaming, hair straightening, painting, textile processing and insole making.

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