Microcapsules and their encapsulation process

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 microcapsules based on a formaldehyde-free polymer shell and a lipophilic active core material with improved thermal stability. Microcapsules with crosslinked acrylate vinyl copolymer shells offer the advantage of high thermal stability, where the microcapsule shell can only be destroyed at temperatures above 250°C, and the shell prevents core leaching at higher temperatures for longer periods (120°C for 30 minutes). This makes the microcapsules suitable for use at elevated temperatures in addition to ambient conditions. The present invention also relates to a process for producing the microcapsules. [Background technology]

[0002] Most leave-on and rinse-off formulations, including cosmetic formulations, contain fragrances or perfumes to impart a pleasant fragrance to the formulation itself or to the surface to which the formulation is applied, whether textiles, skin, or hair. Encapsulation is necessary because fragrances or perfumes are often compounds that are sensitive to various chemicals and oxidation. This can result in undesirable interactions with other formulation components, such as surfactants, resulting in changes in the fragrance notes. Furthermore, most fragrances or perfumes are highly volatile. As a result, a large portion of the fragrance initially added to the formulation volatilizes before application, and the remaining amount of fragrance actually applied to the treated surface also evaporates within a short period of time. To overcome these problems, it has been proposed to incorporate fragrances or perfumes into formulations containing microcapsules. These microcapsules allow for the expensive fragrances or perfumes to be distributed relatively uniformly throughout the formulation without being exposed to other components during storage. By appropriate selection of the capsule shell, it is thus possible to achieve effects such as delayed release or release on demand upon friction or release at higher temperatures.

[0003] Patent document 1 describes an aggregate of encapsulated beneficial agents having an aggregate diameter variation coefficient of 6 to 50%, preferably 8 to 35%, more preferably 12 to about 25%, wherein the aggregate of encapsulated beneficial agents has an average diameter of 3 to 300 μm, preferably 5 to 240 μm, more preferably 10 to 120 μm, the encapsulated beneficial agent 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 μm, preferably 1 to 8 μm, more preferably 1.5 to 6 μm, and a shell thickness variation coefficient of 2 to 30%, preferably 4 to 25%, more preferably 6 to 20%. Also included is the collection of encapsulated benefit agents of claim 1, wherein the shell material comprises poly(vinyl alcohol), poly(vinyl acetate), poly(vinylpyrrolidone), poly(vinyl acetate phthalate), vinyl acetate neodecanoic acid copolymer, vinyl acetate ethylene copolymer, vinyl acetate crotonic acid neodecanoate copolymer, vinyl acetate crotonic acid copolymer, vinyl acetate butyl maleate copolymer, cellulose acetate, cellulose acetate phthalate, ethyl cellulose, hydroxyl propyl methylcellulose phthalate, cellulose acetate butyrate, vinylpyrrolidone vinyl acetate copolymer, poly(styrene-co-maleic acid) isobutyl ester, poly(styrene-co-butadiene), poly(styrene-co-acrylic), and mixtures thereof, but not microcapsules with high thermal stability.

[0004] Patent Document 2(also published in U.S. Patent No. 5,623,669; ... or U.S. Patent No. 5,623,669) discloses a method for preparing an aqueous dispersion of a polymer-encapsulated particulate material, the method comprising obtaining a dispersion of a particulate material in a continuous aqueous phase comprising an ethylenically unsaturated monomer and a stabilizer for the particulate material, and polymerizing the ethylenically unsaturated monomer by non-living free radical polymerization to form a polymer that encapsulates the particulate material, thereby obtaining an aqueous dispersion of the polymer-encapsulated particulate material, wherein the polymerization of the ethylenically unsaturated monomer (a) polymerizing a monomer composition comprising an ionizable ethylenically unsaturated monomer to form a base-responsive, water-swellable, non-living polymer layer that encapsulates a particulate material; (b) polymerizing a monomer composition comprising a non-ionizable ethylenically unsaturated monomer to form a stretchable, water- and base-permeable, non-living polymer layer that encapsulates the base-responsive, water-swellable polymer layer; The present invention teaches a method including:

[0005] Patent Document 2 also teaches a particulate material encapsulated with the resulting polymer, wherein the particulate material is encapsulated by a base-responsive, water-swellable, non-living polymer layer comprising polymerized residues of ionizable ethylenically unsaturated monomers, where the base-responsive, water-swellable, non-living polymer layer is encapsulated by a stretchable, water- and base-permeable, non-living polymer layer comprising polymerized residues of non-ionizable ethylenically unsaturated monomers, but does not relate to microcapsules with high thermal stability.

[0006] Patent Document 10 teaches a consumer product comprising a composition, the composition comprising an auxiliary material and a first population of microcapsules, the first population comprising microcapsules comprising a partitioning modifier and a first fragrance oil in a first weight ratio and having a first average volume-weighted particle size, and a second population of microcapsules comprising microcapsules comprising a partitioning modifier and a second fragrance oil in a second weight ratio and having a second average volume-weighted particle size, wherein the first weight ratio and the second weight ratio are different and / or the first average volume-weighted particle size and the second average volume-weighted particle size are different, and the composition is a fabric care composition and a home care composition. Therefore, Patent Document 10 teaches a consumer product having two different populations of microcapsules, but does not teach microcapsules with high thermal stability.

[0007] Patent Document 11 teaches a method for preparing microcapsules, which includes (a) a step of mixing a free-radically polymerizable and ethylenically unsaturated monomer, an emulsifier, a strong hydrophobic agent, a hydrophobic substance, an initiator, and deionized water to prepare a miniemulsion, and (b) a step of polymerizing the miniemulsion to prepare microcapsules, but does not enable microcapsules with high thermal stability.

[0008] Patent Document 12 teaches microcapsules with capsule cores and capsule walls obtainable by a process including free radical polymerization of an oil-in-water emulsion containing the following components: 30 to 90% by weight, based on the total weight of monomers, of one or more monomers (monomer I) from the group including C1-C24-alkyl esters of acrylic acid and / or methacrylic acid, acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid; 10 to 70% by weight, based on the total weight of monomers, of one or more ethylenically unsaturated crosslinkers (monomer II), where at least 10% by weight, based on the total weight of monomers I, II, and III, is a hyperbranched polymeric crosslinker; 0 to 30% by weight, based on the total weight of monomers, of one or more monounsaturated monomers different from monomer I (monomer III); and a hydrophobic core material. However, this document does not teach microcapsules with high thermal stability.

[0009] Patent Document 13 teaches an encapsulated fragrance composition comprising at least one core-shell microcapsule suspended in a suspending medium, the at least one core-shell microcapsule having a core containing at least one perfume 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 a monomer, a prepolymer, and / or a precondensate, and the encapsulated fragrance composition comprises a polymeric stabilizer which is a reaction product of a polymeric surfactant and a silane containing a functional group capable of forming a covalent bond with the shell. However, this prior art does not disclose the thermal stability of the microcapsule composition.

[0010] Patent Document 14(also published as Patent Document 15) discloses a collection of microcapsules having a capsule core and a capsule shell, the capsule shell being hydrolyzable, the microcapsules being prepared by dispersing a) a polymeric emulsifier and optionally an initiator in an aqueous phase, and b) dispersing in one or more oil phases: i) the initiator and core material; ii) a first multifunctional (meth)acrylate monomer having on average more than one ester group in the monomer and having a hydrophilicity index of less than 20; iii) a second multifunctional (meth)acrylate comprising a hydrophilic multifunctional polar monomer having a hydrophilic index of at least 20, wherein the second multifunctional polar monomer comprises 50% or less of the capsule shell, and the first and second multifunctional (meth)acrylate monomers together comprise more than 80% by weight of the capsule shell; iv) an acidic (meth)acrylate; and v) optionally 0-50 wt. % of an aliphatic polyester having two or more acrylate or methacrylate groups; c) emulsifying one or more oil phases in an aqueous phase under high shear agitation to form an oil-in-water emulsion containing droplets of the core material and oil phase monomers dispersed in the aqueous phase; and d) activating one or more initiators by heat or actinic radiation to react the monomers and optional aliphatic polyester, thereby forming a polymeric capsule shell surrounding the emulsion droplets. Thus, this prior art does not include vinyl acetate monomers, but rather teaches that polyfunctional (meth)acrylate monomers as a variant of shell walls containing butyl acrylate together with polyvinylpyrrolidone initiate the formation of microcapsule shells, and is not directed to capsules with increased thermal stability.

[0011] Patent Document 16 discloses a method for preparing sustained-release microcapsules with multiple cores. This method includes the following steps: dispersing a suspension of a mixture of an acrylate polymer, a volatile organic solvent, a liquid essence, and porous starch in an aqueous solution of a colloidal protective agent by mechanical stirring to form an oil-in-water system; then applying a reduced pressure to remove the volatile organic solvent from the oil-in-water system and causing interfacial phase separation between the acrylate polymer, the liquid essence, and the porous starch to form acrylate polymer microcapsules with the liquid essence and the porous starch encapsulated therein; and then adding an ethylene glycol dimethacrylate prepolymer and performing heat curing to obtain crosslinked acrylate polymer essence microcapsules with multiple cores, i.e., sustained-release microcapsules with multiple cores encapsulated therein. This method is simple to operate and efficient to prepare, and the encapsulated essence is gradually released, the fragrance is long-lasting, and it can be widely applied in the technical fields of cosmetics, household or personal care products, and functional materials.

[0012] Patent Document 17(also disclosed in Patent Document 18, Patent Document 19, or Patent Document 20) discloses a polymeric material comprising, based on total composition weight, a) about 0.01 to about 1% of a first polymer and a second polymer, wherein the first polymer is derived from the polymerization of about 5 to about 100 mole % of a cationic vinyl addition monomer, about 0 to about 95 mole % of a nonionic vinyl addition monomer, about 50 to about 1,950 ppm of a crosslinker containing two or more ethylene functional groups, and about 0 to about 10,000 ppm of a chain transfer agent; and the second polymer is derived from the polymerization of about 5 to about 100 mole % of a cationic vinyl addition monomer, about 0 to about 95 mole % of a nonionic vinyl addition monomer, based on total composition weight. The present invention teaches a composition for fabric and home care products comprising: (a) a polymeric material derived from the polymerization of a methyl acrylate copolymer, about 0 to about 45 ppm of a crosslinker containing two or more ethylenic functional groups, and about 0 to about 10,000 ppm of a chain transfer agent; (b) about 0 to about 35% of a cationic quaternary fabric softener active, wherein the parent aliphatic acyl compound or acid from which the alkyl or alkenyl chain is derived has an iodine value of about 5 to about 60; and (c) a population of perfume microcapsules, wherein the population of perfume microcapsules comprises a microcapsule wall material comprising one or more polyacrylate polymers. The composition is derived from (iii) an anionic monomer selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, and monomers providing a sulfonic or phosphonic acid function, such as 2-acrylamido-2-methylpropanesulfonic acid and salts thereof. Perfume microcapsules containing microcapsule wall materials that essentially comprise cationic vinyl addition monomers of the quaternary ammonium type also fail to teach any improvement in the thermal stability of the microcapsules.

[0013] Patent Document 21 (also published as Patent Documents 22, 23, 24, 25, 26, 27, 28 (Patent Document 29), 30, 31, and 32) teaches microcapsules comprising: i. a lipophilic core material; and ii. a microcapsule shell, wherein the microcapsule shell is formed from an oil-in-water emulsion polymerization of a monomer mixture consisting essentially of: (a) 70 to about 99% by weight of at least one multifunctional ethylenically unsaturated monomer; (b) about 1 to about 30% by weight of at least one unsaturated carboxylic acid monomer or ester thereof; and (c) about 0 to about 30% by weight of at least one vinyl monomer.

[0014] Patent Document 33 (also published in U.S. Patent Nos. 3,277,359, 3,360,361, and 3,370) teaches an aqueous slurry composition comprising an aqueous medium having dispersed therein oily medium-containing microcapsules, the oily medium-containing microcapsules having an ionic acrylate copolymer shell encapsulating the oily medium. Thus, only acrylic polymer-based microcapsules are taught, without any shell structure based on meth(acrylic)-vinyl acetate copolymer, and thermally stable microcapsules are obtained through a different process.

[0015] Patent Document 38 (also published as Patent Document 39, Patent Document 40, Patent Document 41, Patent Document 42, Patent Document 43, Patent Document 44, and Patent Document 45) provides a viscosity of 0.900 to 1.400 g / cm 3 , preferably 0.900 to 1.250 g / cm 3 1. A liquid consumer product comprising core-shell microcapsules having a density in the range of: - The microcapsule shell is formaldehyde-free and 50-100% by weight is 1.05 g / cm 3 It is made of starting materials having the following densities: - the microcapsule core comprises a fragrance composition, which composition comprises: a) 20 to 100% by weight, 0.950 g / cm 3 at least one cyclic fragrance material having a density greater than 1.00 and a Clog P in the range of 1.00 to 6.00; b) 0 to 50% by weight, 0.950 g / cm 3 at least one oil-soluble organic compound having a density greater than c) 0 to 80% by weight, 0.950 g / cm 3 Cyclic aromatic components having a density of 0.950 g / cm 3 at least one material selected from non-cyclic aromatic components having a density that may be greater or less than Including, wherein the sum of a), b), and c) equals 100%, wherein the weight ratio of core material to shell material is in the range of 50:1 to 1:1, and the starting material comprises at least 50% by weight, preferably at least 60% by weight, of (meth)acrylic acid and / or (meth)acrylate, and wherein the loading of microcapsules into the liquid consumer product is in the range of 0.01 to 10% by weight, preferably 0.05 to 2.5% by weight, more preferably 0.1 to 1.25% by weight of the liquid product composition; and thus, the present invention teaches a liquid consumer product in which a density-based shell wall material is selected to encapsulate a selected fragrance, and the shell material does not include any poly / (meth)acrylate-co-vinyl acetate copolymer and results in thermally stable crosslinked microcapsules based on a selected polymerization process.

[0016] Patent documents 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, and 58 disclose a polymerizable composition comprising a core of hydrophobic material composed of at least one fragrance and the following monomers: (a) one or more C1 to C24-alkyl esters of (meth)acrylic acid (monomer A), (b) one or more di- or polyfunctional monomers (monomer B), and (c) optionally, one or more other ethylenically unsaturated monomers (monomer C); and a microcapsule shell obtainable by suspension polymerization of the above-mentioned copolymer, wherein the shear rate for preparing the emulsion is in the range of 150 to 500 rpm, the stirring time for preparing the emulsion is in the range of 15 to 180 minutes, and an anchor-type stirring blade or a MIG stirrer is used for preparing the emulsion, but does not teach any thermally stable microcapsules that may be obtainable from specifically including a vinyl acetate monomer by avoiding the shear rates mentioned in this prior art.

[0017] Since U.S. Patent Nos. 5,611,529, 5,603,529, 5,613,529, 5,623,530, 5,643,545, 5,655,566, 5,677,575 and 5,686,583 teach consumer products comprising a composition, the composition comprising an auxiliary material, a first population of microcapsules, the microcapsules comprising a partitioning modifier and a first fragrance oil in a first weight ratio, the first population having a first average volume weighted particle size, and a second population of microcapsules, the microcapsules comprising a partitioning modifier and a second fragrance oil in a second weight ratio, the second population having a second average volume weighted particle size, wherein the first weight ratio and the second weight ratio are different and / or the first average volume weighted particle size and the second average volume weighted particle size are different, the composition is a fabric care composition and a home care composition, this prior art does not teach that thermally stable microcapsules can be obtained by avoiding partitioning modifiers and based on only one type of microcapsules comprising only one type of fragrance.

[0018] Although microcapsules encapsulating active agents are known in the art, there remains a need to explore microcapsules with lipophilic substances as cores, such as fragrances, that are thermally stable and decompose above 250°C, making them suitable for high temperature applications including fabric steaming, hair straightening, paints, textile processing, and shoe insole manufacturing. [Prior art documents] [Patent documents]

[0019] [Patent Document 1] International Publication No. 2014 / 189980 Brochure [Patent Document 2] International Publication No. 2012 / 162742 Brochure [Patent Document 3] Australian Application Publication No. 2011 / 902127 [Patent Document 4] European Patent Application Publication No. 2714817 [Patent Document 5] Chinese Patent Application Publication No. 104053729 [Patent Document 6] U.S. Patent No. 9,339,781 B2 [Patent Document 7] Australian Patent No. 2012 / 262664B2 [Patent Document 8] New Zealand Patent Application Publication No. 618219 [Patent Document 9] Canadian Patent Application Publication No. 2837897 [Patent Document 10] International Publication No. 2017 / 004339(A1) Brochure [Patent Document 11] International Publication No. 2005 / 002719 Pamphlet [Patent Document 12] US Patent Application Publication No. 2012 / 076843(A1) [Patent Document 13] International Publication No. 2019 / 121736 Brochure [Patent Document 14] International Publication No. 2020 / 190689 Brochure [Patent Document 15] U.S. Patent Application Publication No. 2020 / 0315931 A1 [Patent Document 16] Chinese Patent Application Publication No. 109453724A [Patent Document 17] US Patent Application Publication No. 2017 / 0211019 [Patent Document 18] International Publication No. 2017 / 132101A1 Brochure [Patent Document 19] Japanese Patent No. 6651637B2 Specification [Patent Document 20] European Patent Application Publication No. 3408363A1 [Patent Document 21] International Publication No. 2017 / 123965 Brochure [Patent Document 22] U.S. Patent Application Publication No. 2019 / 0054440 A1 [Patent Document 23] Australian Patent No. 2017 / 207981 B2 [Patent Document 24] European Patent Application Publication No. 3402674 [Patent Document 25] Chinese Patent No. 108778730B Specification [Patent Document 26] Brazilian Patent Application Publication No. 112018014242 [Patent Document 27] US Patent Application Publication No. 2019 / 0054440 [Patent Document 28] JP 2019 / 505375 A [Patent Document 29] Japanese Patent No. 6938514B2 Specification [Patent Document 30] Canadian Patent Application Publication No. 3011107 [Patent Document 31] Indian Patent Application Publication No. 2018 / 17026022 [Patent Document 32] Mexican Patent Application Publication No. 2018 / 008726 [Patent Document 33] International Publication No. 2017 / 040759 Brochure [Patent Document 34] Canadian Patent Application Publication No. 2980193 [Patent Document 35] Chinese Patent Application Publication No. 107530672 [Patent Document 36] Australian Patent Application Publication No. 2016 / 317844 [Patent Document 37] European Patent Application Publication No. 3344382 [Patent Document 38] European Patent No. 2397120B2 [Patent Document 39] International Publication No. 2011 / 158962 Brochure [Patent Document 40] Spanish Patent Application Publication No. 2597980 [Patent Document 41] U.S. Patent No. 9,464,263 B2 [Patent Document 42] Chinese Patent Application Publication No. 102946843 [Patent Document 43] Brazilian Patent Application Publication No. 112012032063 [Patent Document 44] JP 2013 / 530253 A [Patent Document 45] Mexican Patent Application Publication No. 344969 [Patent Document 46] International Publication No. 2014 / 032920A1 Brochure [Patent Document 47] European Patent No. 2890486B1 [Patent Document 48] Chinese Patent No. 104755162B Specification [Patent Document 49] Korean Patent Application Publication No. 1020150052046 [Patent Document 50] Russian Patent Application Publication No. 2015 / 111081 [Patent Document 51] Brazilian Patent Application Publication No. 112015004387 [Patent Document 52] Indonesia Patent Application Publication No. 2016 / 05358 [Patent Document 53] Russian Patent Application Publication No. 0002639909 [Patent Document 54] JP 2015 / 535858 A [Patent Document 55] Canadian Patent Application Publication No. 2882427 [Patent Document 56] Indian Patent Application Publication No. 1199 / CHENP / 2015 [Patent Document 57] Mexican Patent Application Publication No. 2015 / 002649 [Patent Document 58] JP 2017 / 105791 A [Patent Document 59] International Publication No. 2017 / 004339 Brochure [Patent Document 60] US Patent Application Publication No. 2017 / 0002301 [Patent Document 61] Canadian Patent Application Publication No. 2989002 [Patent Document 62] Chinese Patent Application Publication No. 107835681 [Patent Document 63] European Patent No. 3316854 B1 [Patent Document 64] JP 2018 / 522976 A [Patent Document 65] Polish Patent Application Publication No. 3316854 [Patent Document 66] Indian Patent Application Publication No. 2017 / 17045571 [Patent Document 67] Mexican Patent Application Publication No. 364218 [Patent Document 68] Japanese Patent Publication No. 2020 / 073672 Summary of the Invention [Problem to be solved by the invention]

[0020] It is therefore an object of the present invention to provide microcapsules with lipophilic cores which are thermally stable as the microcapsules do not rupture the shell during their application at higher temperatures, thus preventing loss of the lipophilic core and resulting in rupture of the shell under any mechanical stress, releasing the core / benefit agent.

[0021] Another object of the present invention is to provide such microcapsules having a lipophilic core containing a liquid active agent, such as a fragrance.

[0022] It is yet another object of the present invention to provide a process for the synthesis of said microcapsules which involves preheating / prepolymerization of the monomer / shell material in the oil phase, but carried out under a preparation procedure which involves a single polymerization step (i.e., all reactive monomers are copolymerized with each other in one step). [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 shows the olfactory performance of microcapsule compositions. [Figure 2] FIG. 1 shows a TGA thermogram for a microcapsule composition. [Figure 3] FIG. 1 shows an isothermal TGA thermogram for a microcapsule composition. [Figure 4] FIG. 1 shows the olfactory performance of microcapsule compositions after steam treatment at 120° C. for 3 minutes. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention relates to microcapsules comprising a lipophilic core material and a microcapsule shell, the microcapsule shell being formed from an oil-in-water emulsion polymerization of a monomer mixture, greater than 50% by weight of the monomer mixture being composed of monomers having a density greater than 1.05, the monomer mixture comprising: a) greater than 30% by weight, based on the total weight of the monomer mixture, 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.

[0025] In one embodiment, the microcapsules are thermally stable at 250°C.

[0026] In one embodiment, the microcapsules are formaldehyde-free.

[0027] In one embodiment, the microcapsules are characterized in that the log P value of all monomers contained in the monomer mixture is in the range of 0.5 to 4.0.

[0028] 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.

[0029] In one embodiment, the microcapsules are characterized in that the ethylenically unsaturated acid monomer is methacrylic acid.

[0030] In one embodiment, the microcapsules are characterized in that the concentration of ethylenically unsaturated acid monomer in the monomer mixture is 45% by weight or less, based on the total weight of the monomer mixture.

[0031] In one embodiment, the microcapsules are characterized in that the concentration of the ethylenically unsaturated acid monomer in the monomer mixture is comprised between 30 and 45% by weight, based on the total weight of the monomer mixture.

[0032] In one embodiment, the microcapsules comprise monofunctional acrylate and / or methacrylate monomers having the formula:

[0033] [ka] (In the formula, 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-CH3, -(O-CH2-CH2-CH2)nO-CH2-CH3, -(O-CH2-CH2-CH2)nO-CH3, -(O-CH2-CHR3) n -CH3, n=1 to 10, m=2 to 10, and R3=methyl or ethyl a polymerizable molecule having an ester functional group of or a mixture of two or more of the above monomers The present invention is characterized in that the compound is selected from the group consisting of:

[0034] 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.

[0035] In one embodiment, the microcapsules are characterized in that the monofunctional acrylate and / or methacrylate monomer is hydroxyethyl methacrylate.

[0036] In one embodiment, the microcapsules are characterized in that the concentration of monofunctional acrylate and / or methacrylate monomers is comprised between 5 and 50% by weight relative to the total weight of the monomer mixture.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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 comprising less than 30% by weight based on the total weight of the monomer mixture.

[0041] 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% by weight, based on the total weight of the monomer mixture.

[0042] In one embodiment, the microcapsules are characterized in that the concentration of the polyfunctional acrylate and / or methacrylate monomer in the monomer mixture is comprised between 20 and 50% by weight, based on the total weight of the monomer mixture.

[0043] In one embodiment, the microcapsules are characterized in that the concentration of vinyl acetate monomer in the monomer mixture is comprised between 0.05 and 15% by weight, relative to the total weight of the monomer mixture.

[0044] In one embodiment, the microcapsules are characterized by a 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 of at least 95% by weight based on the total weight of the monomer mixture.

[0045] In one embodiment, the microcapsules are characterized in that 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 monomer [a)+b)+c)+d)] is 100% by weight based on the total weight of the monomer mixture.

[0046] In one embodiment, the microcapsules are characterized by a microcapsule particle size in the range of Dv(90) values ​​from 8 to 35 μm.

[0047] In one embodiment, the microcapsules have a lipophilic core material of 0.95 g / cm at 25°C. 3 and has a total log P comprised between 2.5 and 6.0.

[0048] 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 said lipophilic core material, of one or more of the following ingredients: fragrances, profragrances, emollient oils, essential oils, hair-benefiting agents, skin-benefiting agents, conditioner actives, cosmetic care actives, personal care actives, UV absorbers, vitamins, antioxidants, antimicrobials, antivirals, flavors, deodorants, pharmaceuticals, dyes, printing inks, insecticides, biocides, pesticides, coating materials, anti-ageing actives.

[0049] In one embodiment, the microcapsules are characterized in that the lipophilic core material of the microcapsules comprises one or more of the following ingredients: fragrances, essential oils, hair benefit agents, skin benefit agents, antimicrobial agents, antiviral agents, deodorants.

[0050] In one embodiment the microcapsules are characterised in that the weight of the lipophilic core material divided by the weight of the microcapsule shell is comprised between 15 and 0.2, such as between 15 and 0.33, for example between 15 and 0.4.

[0051] 10. An aqueous microcapsule composition comprising water and the microcapsules according to claim 1, wherein the water accounts for 35 to 82% by weight of the total weight of the aqueous microcapsule composition.

[0052] The present invention also provides an aqueous microcapsule composition comprising microcapsules comprising a lipophilic core material and a microcapsule shell, the composition comprising: the microcapsule shell is formed from an oil-in-water emulsion polymerization of a monomer mixture, greater than 50% by weight of the monomer mixture being composed of monomers having a density greater than 1.05, the monomer mixture comprising: a) greater than 30% by weight, based on the total weight of the monomer mixture, 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 the lipophilic core material comprises 15 to 45% by weight of the total weight of the aqueous microcapsule composition; The present invention relates to an aqueous microcapsule composition.

[0053] In one embodiment, the aqueous microcapsule composition comprises one or more emulsifiers, wherein the emulsifiers comprise 0.05 to 5% by weight of the total weight of the aqueous microcapsule composition.

[0054] In one embodiment, the aqueous microcapsule composition is characterized in that the weight of the water, microcapsules, and emulsifier comprises at least 90% by weight of the total weight of the aqueous microcapsule composition.

[0055] The present invention also includes a microcapsule comprising a lipophilic core material and a microcapsule shell, the microcapsule shell is formed from an oil-in-water emulsion polymerization of a monomer mixture, greater than 50% by weight of the monomer mixture being composed of monomers having a density greater than 1.05, the monomer mixture comprising: a) greater than 30% by weight, based on the total weight of the monomer mixture, 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) a vinyl acetate monomer; and the lipophilic core material comprises 15 to 45% by weight of the total weight of the aqueous microcapsule composition; 1. A process for preparing an aqueous microcapsule composition, comprising: 1. dissolving a monomer mixture together with an initiator in an oil phase containing a lipophilic core material and heating the oil phase to form a prepolymer; 2. Dissolving an emulsifier in an aqueous phase; 3. Emulsifying the oil phase of step 1 into the aqueous phase of step 2; 4. Heating the emulsion from step 3 to form a suspension of core-shell microcapsules in water; The present invention relates to a process including:

[0056] In one embodiment, the process for preparing the aqueous microcapsule composition is characterized in that the emulsification step of the core phase in the aqueous phase is achieved by stirring using a propeller-type stirrer at 500-1500 rpm for up to 12 minutes.

[0057] The present invention also relates to non-therapeutic methods of using the claimed microcapsules or aqueous microcapsule compositions, which comprise using the microcapsules to deliver lipophilic core materials for industrial compositions related to home care products, personal care products, textile products, printing and coating applications, pharmaceutical formulation products, consumer goods products, and agricultural industrial formulation products.

[0058] In one embodiment, the non-therapeutic method of use is characterized in that the mechanical stress and temperature conditions to which the microcapsules are exposed are sufficient to rupture the microcapsule shell and release the lipophilic core material.

[0059] In one embodiment, the non-therapeutic use according to the present invention applies to fabric steaming, hair straightening, paints, textile processing, and shoe insole making.

[0060] The following description is directed to specific embodiments pertaining to the present invention.

[0061] As previously discussed herein, the present invention provides formaldehyde-free microcapsules comprising a polymeric shell and a lipophilic active core, which have high thermal stability and break down above 250°C, making them suitable for high temperature applications such as, but not limited to, fabric steaming, hair straightening, paints, textile processing, and shoe insole fabrication, wherein the polymeric shell comprises a crosslinked (meth)acrylic-vinyl acetate copolymer.

[0062] To those skilled in the art, a microcapsule comprising a lipophilic core material and a microcapsule shell that is thermally stable at 250°C means that said microcapsule shell will not be destroyed at 250°C.

[0063] Any suitable measurement method may be advantageously used to measure the characteristic of being thermally stable at 250°C.

[0064] For example, this can be advantageously measured by taking a sample of the microcapsule slurry intended for commercialization, for example the microcapsule slurry obtained at the end of Example 1 herein below, and testing said microcapsule slurry sample using a thermogravimetric analyzer (TGA), subjecting it to a temperature ramp, for example from ambient temperature to 250°C at an increment of 30°C per minute, and measuring the weight loss of the lipophilic core material. If the weight loss of the lipophilic core material is less than 7.5% by weight, preferably less than 5% by weight, relative to the total weight of the encapsulated core material, it can be concluded that the microcapsules are thermally stable at 250°C.

[0065] For example, if the ambient temperature is 20°C, the temperature ramp to 250°C that the sample undergoes and the corresponding TGA observations will take approximately 7 minutes and 40 seconds.

[0066] Therefore, when the microcapsules are examined using a thermogravimetric analyzer (TGA), the microcapsule shell of the encapsulated lipophilic core material will only be destroyed at temperatures above 250°C.

[0067] Advantageously, a further feature of the polymer shell of the microcapsules of encapsulated lipophilic core material of the present invention is that the shell is able to prevent loss of lipophilic core material through leakage while the microcapsules are exposed to 120° C. for extended periods of time, for example, more than 30 minutes. This further supports the thermal stability of the microcapsules, allowing them to maintain their integrity for longer periods of time in applications requiring prolonged heat exposure.

[0068] It includes a polymer made up of constituents that are essentially polymerizable molecules, more than 50% of which have a density of 1.05 g / cm at 25°C. 3 The shell of the present invention has a density of at least 100 ppm, a log P value in the range of 0.5 to 4.0, and has an ester functional group and an ester-forming functional group.

[0069] By definition, Log P refers to the octanol / water partition coefficient (P) of any individual ingredient, which is the ratio between its equilibrium concentration in octanol and its equilibrium concentration in water. Ingredient partition coefficients are expressed in the form of their base 10 logarithm, or Log P, where individual Log P values ​​are typically provided by raw material suppliers. The total Log P value for a fragrance is determined by averaging the individual Log P values ​​on a weight percent basis.

[0070] By definition, density in this specification refers to the individual densities of all materials used, values ​​given in g / cm at 25°C. 3 The values ​​are 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 the ATSM D 369 method.

[0071] Polymerizable molecules in the present invention refer to organic molecules having one or more ethylenically unsaturated moieties.

[0072] By definition, an aqueous microcapsule composition or slurry in the present invention refers to an aqueous medium containing microcapsules dispersed in the presence of an emulsifier, the microcapsules comprising a lipophilic core (e.g., a fragrance) and a polymeric shell formed by polymerization of ethylenically unsaturated molecules initiated by an oil-soluble (thermal) initiator at elevated temperature. The final product of Example 1 refers to an aqueous microcapsule composition or slurry in accordance with the present invention.

[0073] For example, as shown in Example 1 above, in the final slurry, with the emulsifier present, most of the initiator generates lauric acid free radicals which then begin to form crosslinked shell polymer, while the remaining lauric acid free radicals form lauric acid and remain dissolved / trapped within the core.

[0074] By definition, a polymerizable molecule having an ester functionality refers to an ethylenically unsaturated molecule having at least one ester moiety.

[0075] By definition, a polymerizable molecule having an ester-forming functional group is further defined as an ethylenically unsaturated molecule having at least one free acid functional group that can be chemically converted to an ester moiety. Examples of such polymerizable molecules having one free acid functional group include, but are not limited to, acrylic acid, methacrylic acid, crotonic acid, and 2-carboxyethyl acrylate, glutaconic acid, 3,3-dimethylacrylic acid, itaconic acid, maleic acid, fumaric acid, and the like.

[0076] The component in the present invention comprises (a) more than 30% by weight of the total weight of the shell of one or more polymerizable molecules having one free acid functional group.

[0077] The components in this application are (b) a compound of the formula:

[0078] [ka] (Where 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-CH3, -(O-CH2-CH2-CH2)nO-CH2-CH3, -(O-CH2-CH2-CH2)nO-CH3, -(O-CH2-CHR3) n -CH3, n=1 to 10, m=2 to 10, R3 = methyl or ethyl) The polymerizable molecule contains one or more ester functional groups.

[0079] Examples of polymerizable molecules having an ester functionality of one of the above formulas 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.

[0080] The component of the present invention comprises (c) two or more polymerizable molecules having more than one ester functional group that make up less than 60% by weight of the shell, where each of the molecules makes up less than 30% by weight of the shell in the component's composition.

[0081] Examples of polymerizable molecules having more than one ester functional group include, 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.

[0082] The components in this application include (d) vinyl acetate.

[0083] To form a shell according to the present invention, the total weight percent of (a), (b), (c), and (d) is 100%.

[0084] The microcapsules of the present invention are obtained by a three-step process including: i) preheating / prepolymerizing the 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.

[0085] The detailed process for preparing the microcapsules according to the invention advantageously comprises the following steps: 1. a) dissolving polymerizable molecules (i.e., building blocks) and an initiator in a lipophilic core, i.e., oil phase; b) heating the oil phase under nitrogen at 40-55°C with stirring at 100-200 rpm for 15-45 minutes to form a prepolymer; 2. Dissolving an emulsifier in an aqueous phase; 3. Emulsifying the oil phase of step 1 into the aqueous phase of step 2 by stirring using a propeller stirrer at 500-1500 rpm for up to 12 minutes; 4. Heating the emulsion under nitrogen at 100-400 rpm, first at 40-60°C for 15-45 minutes, then at 65-85°C for 4-6 hours; 5. Quenching unreacted monomers at 65-85°C by adding an aqueous persulfate solution; may include:

[0086] The core of the microcapsules in the present invention has a density of 0.95 g / cm at 25°C. 3 The aqueous microcapsule compositions have a density of 15 to 45% by weight of the aqueous microcapsule composition, while the core:shell ratio ranges from 15:1 to 1:5, e.g., 15:1 to 1:3 or 15:1 to 2:5. The total solids content of the aqueous microcapsule composition ranges from 18 to 65% by weight, which includes the lipophilic core-polymer shell microcapsules, emulsifier, and other ingredients.

[0087] The lipophilic core may contain, in essence, any of a wide variety of active ingredients, including but not limited to fragrances, pro-fragrances, 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, flavorings, deodorants, pharmaceuticals, dyes and printing inks, insecticides and biocides, pesticides, coating materials, anti-aging active agents, etc.

[0088] The emulsifier used in the present invention is essentially anionic, nonionic, and cationic small molecules, oligomers, and polymers.Examples of anionic emulsifiers are alkyl sulfates, alkyl ether sulfates, alkyl carboxylates, alkyl succinamidates, alkyl sulfosuccinates, alkyl sulfates such as sodium dodecyl sulfate, alkyl sarcosinate salts, alkyl or alkyl ether or alkylaryl ether phosphate esters, ammonium stearate, ammonium oleate, or ammonium palmitate, sodium stearate, sodium oleate, or sodium palmitate, or potassium stearate, potassium oleate, or potassium palmitate, alkylaryl sulfonates such as sodium dodecylbenzenesulfonate, sodium dialkyl sulfosuccinate, dioctyl sulfosuccinate, sodium dilauryl sulfosuccinate. Nonionic emulsifiers that may be used in the present invention include, but are not limited to, acetylated monoglycerides, lactylated monoglycerides, phosphated or sulfated tristyrylphenol ethoxylates, secondary alcohol ethoxylates, oligoethylene glycol esters of fatty acids, lactylated propylene glycol monoglycerides, sorbitan esters, sorbitan-polyoxyethylene monoglycerides, polyglycerol esters, diacetyl tartaric acid esters of monoglycerides, and succinylated esters of monoglycerides.The polymeric emulsifiers used in this application are diblock copolymers of polyethylene oxide and polyethylene or polypropylene oxide, poly(styrene sulfonate) sodium salt, isobutylene-maleic anhydride copolymer, gum arabic, sodium alginate, carboxymethyl cellulose, cellulose sulfate and pectin, poly(styrene sulfonate), gum arabic, carrageenan, sodium alginate, pectinic acid, tragacanth gum, and nonionic surfactants such as agar, carboxymethyl starch, phosphated starch, lignosulfonic acid, polyacrylic acid, polymethacrylic acid, acrylate butyl acrylate copolymer or crotonic acid homopolymers and copolymers, vinylbenzenesulfonic acid or 2-acrylamido-2-methylpropanesulfonic acid homopolymers and copolymers, and partial amides or partial esters of such polymers and copolymers, carboxy-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, and phosphoric acid-modified polyvinyl alcohol, and mixtures thereof.

[0089] The amount of emulsifier ranges from 0.05 to 5% by weight of the microcapsule composition described herein.

[0090] In one non-limiting embodiment, the initiator used and dissolved in the lipophilic core to prepare the microcapsules is a thermal initiator selected from the group consisting of dibenzoyl peroxide, dioctanoyl peroxide, dilauroyl peroxide, didecanoyl peroxide, tert-butyl peracetate, tert-butyl perlaurate, tert-butyl perbenzoate, dicetyl peroxydicarbonate, di(4-tert-butylcyclohexyl)peroxydicarbonate, tert-butyl hydroperoxide, cumene hydroperoxide, cumene ethyl peroxide, diisopropylhydroxydicarboxylate, and combinations thereof.

[0091] The initiator used in this application is 0.2 to 5% by weight of the microcapsule composition.

[0092] In one non-limiting embodiment, a quencher is used during the preparation of microcapsules. For example, in the present invention, ammonium peroxodisulfate or potassium peroxodisulfate is present as a quencher in the form of an aqueous solution in an amount of 0.02 to 0.5% by weight of the microcapsule composition. Potassium peroxodisulfate is also known as potassium persulfate (KSO). It is commonly used as an oxidizing agent and polymerization initiator in organic synthesis.

[0093] The particle size of the microcapsule compositions presented in this invention ranges from 8 to 35 μm in Dv(90) value as measured using a Malvern Mastersizer 3000.

[0094] Products used: The microcapsule compositions according to the present invention are suitable for use in, but not limited to, home and personal care products, textile products, printing and coating applications, pharmaceutical formulations, consumer goods, and agricultural and industrial formulation products.

[0095] Non-limiting examples of home care products comprising the microcapsules according to the present invention are in the following categories: 1. air care products, 2. house cleaners, 3. dishwashing products, and 4. laundry / fabric care products. Examples of air care products are broadly divided into i) aqueous air freshener liquids, gels, sprays, upholstery refreshers and sprays, and liquids for metered dosing articles; and ii) tablets, pellets, cakes, pastes, etc. 2. House cleaners comprising the microcapsule compositions according to the present invention include multi-surface cleaners, carpet cleaners, hard surface cleaners, etc. 3. Dishwashing products, according to the present application, include liquid dishwashing agents, dishwashing tablets, and dishwashing bars. 4. Laundry / fabric care products, according to one embodiment of the present application, include primarily liquid and solid laundry detergents, fabric conditioners, fabric refreshers, fabric strengtheners, stain removal articles, fabric refresher sprays, solid fabric softeners and refresher articles, and fabric refresher cones.

[0096] Examples of personal care products having a lipophilic core as the active agent in the microcapsules according to the present invention are shampoos, conditioners, depilatories, hair styling gels, hair colorants, antiperspirants / deodorants, aqua mists, and leave-on and rinse-off hair and skin care compositions such as sprayable and roll-on products, body washes, shower gels, hand washes, soaps, body lotions, facial cleansers, face masks, face creams, face serums, sunscreens, etc. Examples of cosmetic products comprising microcapsules include, but are not limited to, lip gloss products, foundations, foundation primers, eye shadows, etc.

[0097] Non-limiting examples of pharmaceutical formulations are primarily dermatological products such as ointments, sprays, creams, lotions, gels, and transdermal patches.

[0098] The microcapsules containing fragrance, antimicrobial, and antiviral agents according to this report are used in textile / fabric manufacturing to combat odors and microorganisms. Additionally, the microcapsules are utilized in diapers and sanitary napkins.

[0099] Printing formulations comprising microcapsules according to the present application are used in inkjet printing, spraying, flexographic printing, roller and cylinder printing, stencil printing, digital printing, etc., wherein the lipophilic core of the microcapsules comprises dyes and printing inks, fragrances, pro-fragrances, antimicrobial and antiviral agents, deodorants, etc. According to one embodiment of the present application, the coating material for the encapsulation is selected from non-limiting examples including oil-soluble materials whose core has film-forming properties on skin and hair, such as vinylpyrrolidone / hexadecene and vinylpyrrolidone / eicosene copolymers, tricontanyl polyvinylpyrrolidone, etc.

[0100] Non-limiting examples of consumer products containing microcapsules according to the present invention are paints, hard surface polishes, shoe insoles, and the like. [Example]

[0101] Example 1. Preparation of a microcapsule composition according to the present invention Raw materials used in the preparation of aqueous slurries of microcapsules Composition of oil phase 1: Air freshener: 30g (lipophilic core) 1a. Composition of the fragrance:

[0102] [Table 1] The density of the fragrance is 0.8446 g / cm at 25°C. 3 and the total (average) Log P is 3.61. 1b. Methacrylic acid: 2.2g 1c. 2-Hydroxyethyl methacrylate: 0.65g 1d. Ethylenediol dimethacrylate: 1.05g 1e. Pentaerythritol tetraacrylate: 1.25g 1f. Vinyl acetate: 0.61g 1g. Dilauramiperoxide: 1.2g

[0103] Composition of aqueous phase 2: Water: 57.8g 25% aqueous solution of sodium dodecyl sulfate: 8g

[0104] Composition of aqueous phase 3: 0.13 g potassium peroxodisulfate in 10 g water

[0105] Process for preparing microcapsules Table 1. Detailed process for preparing microcapsule formulations according to the present invention

[0106] [Table 2]

[0107] Comparative Examples 2 to 3. Preparation of prior art microcapsule compositions containing the fragrances of the present invention to enable comparison of olfactory properties Table 2. Comparative Examples 2-3 for Prior Art Microcapsule Compositions

[0108] [Table 3]

[0109] Characterization of microcapsule composition: Particle size analysis: Particle size is analyzed using a Mastersizer 3000 equipped with a Hydro MV wet dispersion unit. Dilute aqueous solutions (0.5 wt %) of the microcapsule compositions of Example 1 and Comparative Examples 2 and 3 are measured, and the data are analyzed using the Mie scattering model and are shown in Table 3. Table 3. Dv(90) values ​​of the microcapsule compositions of Example 1 and Comparative Examples 2 and 3

[0110] [Table 4]

[0111] Analysis of the percentage of free oil after microencapsulation : 1 g of the microcapsule composition slurry of Example 1 is mixed with 5 g of hexane in a sealed tube. The mixture is shaken in an orbital shaker at 300 rpm for 15 minutes. The sample is then allowed to stand for 10 minutes. The supernatant is passed through a 0.45 μm filter and subjected to GC analysis. The remaining fragrance is quantified using an Agilent INTOVU 9000 G3950A GC with column part number: 19091S-433UI-INT HP-5MS UI (30 m, 0.25 μm). The microcapsule composition of Example 1 has almost no remaining free oil (0.13% of the total core). Table 4. Free oil analysis of microcapsule compositions of Example 1 and Comparative Examples 2 to 3

[0112] [Table 5]

[0113] This represents a very good indication of the excellent encapsulation properties of our microcapsules, as it is becoming increasingly important to develop consumer products that release active core materials on demand without facing potential disadvantages that may arise from the presence of excess lipophilic materials (before use) outside the microcapsules and inside the consumer product. This is beneficial for the end use of microcapsules in consumer products, as it ensures better post-rub performance of the microcapsules (due to efficient encapsulation of the core fragrance) through application through the consumer product, for example, when fabrics are treated with a fabric softener containing the microcapsules. The exceptional thermal stability of the microcapsules according to the present invention allows them to be used at higher temperatures, for example, during steam treatment of fabrics treated with a product containing the microcapsules.

[0114] Olfactory performance of microcapsules of fragrance cores of Example 1 and Comparative Examples 2 and 3 A conventional fabric softener formulation is prepared in water containing 5% Stepantex SP-90 as a softening active and 0.1% sodium benzoate as a preservative, as suggested by the supplier (Stepan Company, Northbrook, IL 60062, United States). Separate fabric softener formulations are prepared using the individual microcapsule compositions of Example 1 and Comparative Examples 2-3, while maintaining 0.3% by weight of encapsulated fragrance cores in the final fabric softener formulation. Cotton fabrics are washed and treated with the fabric softener formulation (a dosage of 5 g of fabric softener formulation in 1 L of water), rinsed for 10 minutes, and then allowed to dry under ambient conditions. The olfactory profile of the dried fabrics is recorded by trained panel members for the pre-rubbing and post-rubbing stages of the fabrics. The average fragrance intensity results are shown in Figure 1. Intensity ratings range from 1 to 5, with 1 being the weakest and 5 being the strongest on an incremental scale. Example 1 exhibits the highest post-rub strength compared to prior art microcapsule compositions at the same loading level of core (fragrance).

[0115] Thermal Stability of Microcapsule Compositions A. Thermal Stability of Microcapsules Thermal Stability of Microcapsules: The microcapsule compositions were analyzed using a Perkin TGA 4000 instrument. In this instrument, slurry samples were heated under a nitrogen atmosphere from 30 to 500°C at a ramp rate of 30°C / min, followed by heating to 800°C at a ramp rate of 50°C / min. The major weight loss in the thermogram correlates with the accompanying phase change in the microcapsule composition. In the thermogram of Figure 2, a sharp drop in weight is observed around 150-170°C, which is primarily related to the loss of water from the composition. The subsequent weight loss is related to the destruction of the shell and evaporation / loss of the core (fragrance). The microcapsule composition of Example 1 exhibits exceptional stability around 250°C, exhibiting very little weight loss. Therefore, the high thermal stability of the microcapsule composition of the present invention is clearly demonstrated.

[0116] B. Core loss at high temperatures over long periods of time Example 1 and Comparative Example 3 were investigated for core loss at high temperatures over a long period (30 minutes). This was done to ensure core leakage at high temperatures. For high-temperature microcapsule applications, preventing core loss at high temperatures is essential. Example 2 was not considered due to its poor performance (as evidenced in Figure 1). The sample was heated from 30 to 120°C at a ramp rate of 3°C / min and then held at 120°C for 30 minutes. The sample was further heated to 800°C at a ramp rate of 50°C / min under a nitrogen atmosphere. The weight loss for the microcapsule composition was monitored over time at 120°C and is shown in Figure 3. It is clear from Figure 3 that the microcapsule composition of Example 1 showed no weight loss within 30 to 60 minutes while the microcapsules were exposed to 120°C. On the other hand, Example 3 showed significant core loss at high temperatures (almost 10% weight loss). Therefore, with the shell composition of the present invention, there was no core (fragrance) loss. This also demonstrates the importance of the present invention for applications at higher temperatures.

[0117] C. High temperature application Steam Treatment of Fabrics Applied with Fabric Softeners Comprising Microcapsules: Cotton fabrics that have been washed and treated with a fabric softener as detailed hereinabove, comprising the microcapsule composition of Example 1 of the present invention, are exposed to high-temperature steam for 3 minutes. The fabrics are then cooled to room temperature before undergoing pre-rub and post-rub evaluations. As noted above, strength ratings range from 1 to 5, with 1 being the weakest and 5 being the strongest on an incremental scale. It has been observed that after the steam treatment process, the strength of the microcapsules is negligibly affected, based on the average post-rub values.

Claims

1. 1. A microcapsule comprising a lipophilic core material and a microcapsule shell, the microcapsule shell being formed from an oil-in-water emulsion polymerization of a monomer mixture, greater than 50% by weight of the monomer mixture being made up of monomers having a density greater than 1.05, the monomer mixture comprising: a) greater than 30% by weight, based on the total weight of the monomer mixture, 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.

2. 10. The microcapsules of claim 1, which are thermally stable at 250°C.

3. 10. The microcapsules of claim 1, which are formaldehyde-free.

4. 2. The microcapsule of claim 1, wherein the log P values ​​of all monomers contained in the monomer mixture are in the range of 0.5 to 4.

0.

5. 2. The microcapsules of 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 foregoing acids.

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

7. 7. The microcapsule of claim 5, wherein the concentration of the ethylenically unsaturated acid monomer in the monomer mixture is 45% by weight or less, based on the total weight of the monomer mixture.

8. 7. Microcapsules according to claim 5 or 6, wherein the concentration of the ethylenically unsaturated acid monomer in the monomer mixture is comprised between 30 and 45% by weight relative to the total weight of the monomer mixture.

9. The monofunctional acrylate and / or methacrylate monomers may be represented by the formula: 【Chemical 1】 (In the formula, R1 = H / CH 3 and R2=-OH、-(CH 2 ) n -OH、O-CH 3 、-O-(CH 2 ) m -OH、-O-(CH 2 ) n -CH 3 、-(O-CH 2 -CH 2 ) n -OH、-(O-CH 2 -CH 2 -CH 2 ) n -OH、-(O-CH 2 -CH 2 ) n -O-CH 3 、-(O-CH 2 -CH 2 ) n -O-CH 2 -CH 3 、-(O-CH 2 -CH 2 -CH 2 )n-O-CH 2 -CH 3 、-(O-CH 2 -CH 2 -CH 2 )n-O-CH 3 、-(O-CH 2 -CHR3) n -CH 3 であり、 n=1 to 10, m=2 to 10, and R3=methyl or ethyl. a polymerizable molecule having an ester functional group of one of or a mixture of two or more of the above monomers The microcapsules of claim 1 selected from:

10. 2. The microcapsules of 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. 2. The microcapsule of claim 1, wherein the monofunctional acrylate and / or methacrylate monomer is hydroxyethyl methacrylate.

12. Microcapsules according to any one of claims 9 to 11, wherein the concentration of monofunctional acrylate and / or methacrylate monomers is comprised between 5 and 50% by weight relative to the total weight of the monomer mixture.

13. 2. The microcapsule of claim 1, wherein the multifunctional acrylate and / or methacrylate monomer is selected from polymerizable molecules having more than one ester functional group.

14. 2. The microcapsules of 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 foregoing monomers.

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

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

17. Microcapsules according to any one of claims 13 to 15, wherein the concentration of multifunctional acrylate and / or methacrylate monomers in the monomer mixture is comprised between 20 and 50% by weight relative to the total weight of the monomer mixture.

18. 2. Microcapsules according to claim 1, wherein the concentration of vinyl acetate monomer in the monomer mixture is comprised between 0.05 and 15% by weight relative to the total weight of the monomer mixture.

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

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

21. 2. The microcapsules of claim 1, wherein the particle size of the microcapsules is in the range of Dv(90) values ​​from 8 to 35 μm.

22. The lipophilic core material of the microcapsules has a viscosity of 0.95 g / cm at 25°C. 3 2. Microcapsules according to claim 1, having a density of:

23. 10. The microcapsules of claim 1, wherein the lipophilic core material of the microcapsules comprises at least 95% by weight, based on the total weight of the lipophilic core material, of one or more of the following ingredients: fragrances, pro-fragrances, emollient oils, essential oils, hair benefit agents, skin benefit agents, conditioner actives, cosmetic care actives, personal care actives, UV absorbers, vitamins, antioxidants, antimicrobials, antivirals, flavors, deodorants, pharmaceuticals, dyes, printing inks, insecticides, biocides, pesticides, coating materials, anti-aging actives.

24. 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, deodorant.

25. 2. Microcapsules according to claim 1, wherein the weight of the lipophilic core material divided by the weight of the shell of the microcapsule is comprised between 15 and 0.

33.

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

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

28. 27. The aqueous microcapsule composition of claim 26, comprising one or more emulsifiers, wherein the emulsifiers comprise from 0.05 to 5% by weight of the total weight of the aqueous microcapsule composition.

29. 30. The aqueous microcapsule composition of claim 28, wherein the weight of the water, microcapsules, and emulsifier comprises at least 90% by weight of the total weight of the aqueous microcapsule composition.

30. A process for preparing the aqueous microcapsule composition of any one of claims 26 to 29, comprising the steps of:

5. Dissolving the mixture of monomers together with an initiator in an oil phase containing the lipophilic core material and heating the oil phase to form a prepolymer; 6. Dissolving an emulsifier in the aqueous phase; 7. Emulsifying the oil phase of step 1 into the water phase of step 2; 8. Heating the emulsion from step 3 to form a suspension of core-shell microcapsules in water; The process includes:

31. 31. The process of claim 30, wherein the step of emulsifying the core phase in the aqueous phase is achieved by stirring using a propeller type agitator at 500-1500 rpm for up to 12 minutes.

32. 30. A non-therapeutic use of the microcapsules of any one of claims 1 to 25 or the aqueous microcapsule composition of any one of claims 26 to 29, comprising using the microcapsules to deliver a lipophilic core material for industrial compositions relating to home care products, personal care products, textile products, products for printing and coating applications, pharmaceutical formulation products, consumer goods products, and agro-industrial formulation products.

33. 33. A non-therapeutic method of use according to claim 32, wherein the mechanical stress and temperature conditions to which the microcapsules are exposed are sufficient to rupture the microcapsule shell and release the lipophilic core material.

34. 34. Non-therapeutic use according to claim 32 or 33 for fabric steaming, hair straightening, paints, textile processing and making shoe insoles.

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