阅读说明：本技术 非球形微囊 (Non-spherical microcapsule ) 是由 金华进 潘晓赟 于 2018-12-04 设计创作，主要内容包括：公开了包含核和壳的非球形微囊,所述核包含有益剂,所述壳包含直径为10至300nm的纳米颗粒和聚脲。(Non-spherical microcapsules comprising a core comprising a benefit agent and a shell comprising nanoparticles having a diameter of 10 to 300nm and a polyurea are disclosed.)

1. A non-spherical microcapsule comprising:

a) a core comprising a benefit agent, and

b) a shell comprising nanoparticles having a diameter of 10 to 300nm and polyurea.

2. The microcapsule according to claim 1, wherein the benefit agent is a fragrance, a pro-fragrance or a mixture thereof, preferably the benefit agent is a fragrance.

3. A microcapsule according to claim 1 or 2, wherein the weight ratio of the nanoparticles to the benefit agent is preferably from 1:3 to 20: 1.

4. A microcapsule according to any preceding claim wherein the nanoparticles comprise a polysaccharide, preferably a cellulose derivative, more preferably ethyl cellulose.

5. A microcapsule according to any preceding claim wherein the polyurea is the reaction product of the polymerisation of hexamethylene diisocyanate and diethylenetriamine.

6. A microcapsule according to any preceding claim wherein the weight ratio of the nanoparticles to the polyurea is from 1:10 to 10: 1.

7. A microcapsule according to any preceding claim, wherein the microcapsule has a rod-like or ellipsoid-like shape.

8. A microcapsule according to any preceding claim, wherein the microcapsule has an average length of from 0.5 to 100 microns, preferably from 1 to 65 microns.

9. A microcapsule according to any preceding claim, wherein the microcapsule has an aspect ratio of from 1.3:1 to 20:1, preferably from 1.5:1 to 5: 1.

10. A process for the preparation of non-spherical microcapsules according to any one of claims 1 to 9, comprising the steps of:

a) forming a non-spherical emulsion comprising a benefit agent by nanoparticles having a diameter of 10 to 300 nm; and

b) polyurea is formed at the interface of the emulsion.

11. A home or personal care composition comprising microcapsules according to any preceding claim.

12. The composition of claim 11, wherein the composition comprises a cleansing surfactant.

Technical Field

The present invention relates to microcapsules for delivering benefit agents. In particular, the present invention relates to non-spherical microcapsules comprising: (a) a core comprising a benefit agent, and (b) a shell comprising nanoparticles having a diameter of 10 to 300nm and polyurea.

Background

Many home care and personal care products seek to deliver benefit agents to substrates such as textiles, hard surfaces, hair and skin. In order to achieve long lasting benefit agent release properties, it has been proposed to encapsulate benefit agents in microcapsules as a means, particularly for perfumes. When applied, the microcapsules may be deposited on a substrate, for example on a garment, and burst by the action of pressure and/or friction when the user puts on the garment. The perfume is released, giving the user an excellent feeling.

US20140206587 a1(Unilever) discloses a composition comprising benefit agent delivery particles comprising at least one of hydroxypropyl methylcellulose, hydroxyethyl methylcellulose, hydroxypropyl guar, hydroxyethyl ethylcellulose or methylcellulose. Preferably, non-polysaccharide polymers such as aminoplasts are also present. The benefit agent delivery particle may comprise a perfume. Particles containing benefit agents using certain of the above nonionic, substituted cellulose derivatives as delivery aids are effective on both cotton and polyester as well as on hair.

US20140213499 a1(Unilever) discloses benefit agent delivery particles comprising dextran as a delivery aid. The deposition system is effective on cotton and polyester and is stable to hydrolysis and enzymatic attack.

WO16177607 a1(Unilever) discloses microcapsules containing a benefit agent inside a polyurea shell, wherein the polyurea has covalently bonded thereto a nonionic polysaccharide deposition polymer. Nonionic deposition polymers are known to provide enhanced deposition on cellulosic materials relative to other types of shell materials. When attached to polyurea, they were found to provide reduced microcapsule agglomeration and the ability of the microcapsules to remain better dispersed in surfactant containing products than when attached to prior art microcapsules.

In many respects, however, there is still room for improvement. One aspect is to improve the efficiency of deposition of the encapsulated microcapsules. Deposition aids are one way to improve deposition efficiency. However, the use of deposition aids is not always desirable.

We have realised that another alternative to improving deposition efficiency is to provide non-spherical microcapsules. However, the microcapsules may agglomerate when they are prepared due to surface interaction of the microcapsules. In addition, when the microcapsules are incorporated into a home care or personal care product, ingredients in the product (e.g., surfactants) may affect the stability of the microcapsules. Therefore, we developed non-spherical microcapsules with a shell comprising nanoparticles of 10 to 300nm in diameter and polyurea. It has surprisingly been found that such microcapsules are well dispersed and can be stable in the presence of surfactants.

Disclosure of Invention

In a first aspect, the present invention relates to a non-spherical microcapsule comprising a core comprising a benefit agent and a shell comprising nanoparticles having a diameter of 10 to 300nm and polyurea.

In a second aspect, the present invention relates to a process for the preparation of microcapsules of the composition of the invention, comprising the steps of: (a) forming a non-spherical emulsion comprising a benefit agent by nanoparticles having a diameter of 10 to 300 nm; and (b) forming polyurea at the interface of the emulsion.

In a third aspect, the present invention relates to a home or personal care composition comprising the microcapsules of the present invention.

All other aspects of the invention will become more readily apparent when considering the detailed description and the following examples.

Detailed Description

Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about".

All amounts are by weight of the composition, unless otherwise indicated.

It should be noted that in specifying any range of values, any particular upper value can be associated with any particular lower value.

For the avoidance of doubt, the word "comprising" is intended to mean "including", but not necessarily "consisting of or" consisting of. In other words, the listed steps or options need not be exhaustive.

The disclosure of the invention as found herein is to be considered to cover all embodiments as found in the claims as being multiply dependent upon each other, irrespective of whether the claims may be found without such multiple dependencies or redundancies.

"melting point" refers to the temperature at which a single compound changes from a solid to a liquid at atmospheric pressure. When used for the melting point of the mixture, "melting point" refers to the slip melting point (slip melting point). The slip melting point is an indication of the temperature at which fat softens and becomes sufficiently fluid to slip in an open capillary. The slip melting point can be measured according to AOCS Cc 3-25.

As used herein, unless otherwise indicated, "diameter" refers to the diameter in the non-aggregate state. For polydisperse samples having particles with diameters not exceeding 1 μm, diameter means, for example, with an instrument such as a Zetasizer Nano^TM(malvern instruments Ltd, UK), z-average microcapsule diameter measured using dynamic light scattering (see international standard ISO 13321). For polydisperse samples with particles having a diameter greater than 1 μm, diameter means that a system conforming to the requirements set forth in ISO13320 (e.g., Mastersizer) can be used, for example^TM2000, available from Malvern Instruments Ltd), apparent volume median diameter of the microcapsules measured by laser diffraction (D50, also known as × 50 or sometimes as D (0.5)).

As used herein, "aspect ratio" refers to the ratio of the length to the width of the microcapsule. Both length and width can be measured by optical microscopy, for example, Leica DM 2500P. As used herein, "length" refers to the longest measurable distance of the microcapsule in the optical image. As used herein, "width" refers to the longest measurable distance of the microcapsule in an optical image along a direction perpendicular to the length of the microcapsule.

Preferably, the microcapsules are mononuclear microcapsules. The shape of the microcapsules may be any shape, but preferably the microcapsules have a rod-like or ellipsoid-like shape. Preferably, the microcapsules have an aspect ratio of 1.3:1 to 20:1, more preferably 1.4:1 to 10:1, even more preferably 1.5:1 to 5:1, yet even more preferably 1.8:1 to 4: 1.

The microcapsules have an average length of 0.5 to 100 μm, more preferably 1 to 65 μm, even more preferably 3 to 50 μm, still even more preferably 7 to 35 μm, most preferably 12 to 25 μm.

A wide variety of benefit agents may be incorporated into the microcapsules. The benefit agent may comprise a fragrance, pro-fragrance (pro-fragrance), organic sunscreen, skin lightening agent, anti-aging agent, or mixtures thereof. More preferably, the benefit agent is selected from fragrances, pro-fragrances, organic sunscreens, skin lightening agents or mixtures thereof. Even more preferably, the benefit agent is a fragrance, a pro-fragrance, or a mixture thereof. Most preferably, the benefit agent is a fragrance.

Typically, the flavoring agent comprises a component having a boiling point, measured at one atmosphere, of less than 300, more preferably 100-. It is also advantageous to include components with a LogP of less than 3.0 (i.e., those that will partition into water).

The pro-flavoring agent may be, for example, a food lipid. Food lipids generally contain structural units with significant hydrophobicity. Most lipids are derived from fatty acids. In these "acyl" lipids, fatty acids are predominantly present as esters and include mono-, di-, tri-acylglycerols, phospholipids, glycolipids, glycol esters, waxes, sterol esters, and tocopherols.

The fragrance is generally present in an amount of 10-85% by total weight of the microcapsule, preferably 15 to 75% by total weight of the microcapsule. The flavourant suitably has a molecular weight of 50 to 500 daltons. The pro-fragrance may have a higher molecular weight, typically 1-10 kdaltons.

The core preferably comprises a fatty ester, a silicone oil, an alkane, or a mixture thereof. More preferably, the core comprises silicone oil, coconut oil, corn oil, cottonseed oil, olive oil, palm oil, soybean oil, peanut oil, pumpkin seed oil, corn oil, sunflower oil, peanut oil, safflower oil, sesame oil or mixtures thereof. Even more preferably, the core comprises sunflower oil, coconut oil or a mixture thereof, most preferably, the core comprises sunflower oil. Preferably, the core comprises an organic solvent having a melting point of less than 20 ℃, more preferably less than 0 ℃. In the case that the fatty ester is a mixture of different fatty esters, the melting point refers to the melting point of the mixture.

The shell comprises nanoparticles having a size of 10 to 300 nm. The nanoparticles may be inorganic nanoparticles such as calcium carbonate, or polymeric particles. Preferably, the nanoparticles are polymer particles. Preferably, the nanoparticles comprise a polysaccharide, more preferably a cellulose derivative, even more preferably ethylcellulose, and most preferably the nanoparticles are ethylcellulose nanoparticles. Preferably, the nanoparticles are spherical or quasi-spherical in shape.

The degree of substitution of the ethylcellulose is preferably 2 to 3, more preferably 2.2 to 2.8. The degree of substitution refers to the average number of hydroxyl groups substituted per anhydroglucose unit ("monomer"). If all three hydroxyl groups are replaced, the maximum theoretical number of degrees of substitution is 3.

Suitable polysaccharides, preferably ethylcellulose, preferably have a dynamic viscosity of 5 to 300cP, more preferably between 30 and 230cP, and even more preferably 60 to 150cP under such conditions, at a concentration of 5% by weight in toluene/ethanol (80: 20 by weight).

Preferably, the nanoparticles have a diameter of 20 to 250 nm. More preferably, the diameter of the nanoparticles is 40 to 200 nm. Even more preferably, the nanoparticles have a diameter of 50 to 160 nm.

Without being bound by any theory or explanation, polyurea is believed to be formed in the gaps between the nanoparticles, and thus the microcapsules are enhanced to be stable, even in the presence of surfactants. The polyurea may be any reaction product of a polymerization between at least one polyisocyanate and at least one amine. Preferably, the polyurea is preferably at least one polyisocyanate and at least onehas-NH₂And/or a polymeric reaction product between polyamines of-NH groups. Preferably, the weight ratio of polyisocyanate to polyamine is from 3:1 to 15:1, more preferably from 1:1 to 5:1, even more preferably from 2:1 to 3: 1.

The polyisocyanates preferably contain an average of 2 to 4-N ═ C ═ O groups. More preferably, the polyisocyanate comprises two isocyanate functional groups. Preferably, the polyisocyanate is water insoluble.

The polyisocyanate may be aliphatic or aromatic, but preferably the polyisocyanate comprises an aliphatic polyisocyanate. Suitable aliphatic polyisocyanates include Hexamethylene Diisocyanate (HDI), tetraalkyl xylene diisocyanate, cyclohexane diisocyanate, 1, 12-dodecane diisocyanate, 1, 4-tetramethylene diisocyanate, 1, 3-and 1, 4-cyclohexane diisocyanate, 1-isocyanato-3, 3, 5-trimethyl-5-isocyanatomethyl-cyclohexane (isophorone diisocyanate), 4 ' -, 2 ' -and 2,4 ' -dicyclohexyl-methane diisocyanate, or mixtures thereof. More preferably, the polyisocyanate comprises hexamethylene diisocyanate.

The polyamine is preferably a polyalkylene polyamine, which preferably contains at least 3 amino groups. More preferably, the polyamine comprises Diethylenetriamine (DETA), triethylenetetramine (TETA), Tetraethylenepentamine (TEPA), Pentaethylenehexamine (PEHA), or mixtures thereof. Even more preferably, the polyamine comprises diethylenetriamine.

Most preferably, the polyurea is the polymerized reaction product of hexamethylene diisocyanate and diethylenetriamine.

The weight ratio of nanoparticles to benefit agent is preferably from 1:3 to 20:1, more preferably from 1:2 to 12:1, and even more preferably from 1:1.5 to 5: 1. The weight ratio of nanoparticles to polyurea is preferably from 1:10 to 10:1, more preferably from 1:6 to 6:1, and even more preferably from 1:3 to 3: 1.

In order to further improve the deposition efficiency, it is preferred that the microcapsules further comprise a deposition aid located outside the surface. The deposition aid is preferably a polysaccharide. It should be noted that the polysaccharide as a deposition aid is chemically different from the polysaccharide that may be contained in the nanoparticles.

Preferably, the polysaccharide is cellulose, a cellulose derivative or another beta-1, 4-linked polysaccharide having an affinity for cellulose, preferably mannan, glucan, glucomannan, xyloglucan, galactomannan and mixtures thereof. More preferably, the polysaccharide is selected from xyloglucan and galactomannan, cellulose and derivatives thereof. Most preferably, the deposition polymer is selected from locust bean gum, xyloglucan, guar gum or mixtures thereof. Preferably, the polysaccharide has only β -1,4 linkages in the polymer backbone.

Alternatively or additionally, the polysaccharide may be selected from hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl methylcellulose, hydroxypropyl guar, hydroxyethyl ethylcellulose and methylcellulose. Preferred molecular weights of the polysaccharide deposition aid are in the range of about 5kDa to about 500kDa, preferably 10kDa to 500kDa, more preferably 20kDa to 300 kDa. Preferably, the deposition aid is present at a level such that the ratio of polymer to microencapsulated solids is in the range of from 1:500 to 3:1, preferably from 1:200 to 1: 3. The deposition aid is preferably bonded to the shell using covalent bonds and/or strong adsorption, more preferably covalent bonds.

The microcapsules may be prepared in any suitable manner. Preferably, however, the method comprises: (a) forming a non-spherical emulsion comprising a benefit agent by nanoparticles having a diameter of 10 to 300 nm; and

(b) polyurea is formed at the interface of the emulsion.

Preferably, the method further comprises the step (i) of mixing water, fatty ester, benefit agent and nanoparticles prior to step (a). In order to obtain microcapsules with a higher aspect ratio, it is preferred to add a thickener in step (i). Preferably, the thickener comprises a gum, a starch derivative, a cellulose derivative, a carboxyvinyl polymer, or a mixture thereof. More preferably, the thickener is a gum. Even more preferably, the thickener is guar gum, locust bean gum, xanthan gum or mixtures thereof. Most preferably, the thickener is locust bean gum.

To form a more stable emulsion, it is preferred to incorporate a cationic polymer in step (i). The cationic polymer is preferably a polyquaternium, more preferably polyquaternium-7.

The polyurea is formed by polymerizing at least one polyisocyanate and at least one amine. Preferably, the polyisocyanate is in the oil phase of the emulsion and the amine is in the water phase of the emulsion. Preferably, step (b) is carried out at-20 to 10 ℃.

The final product of the invention may be in any physical form, but is preferably an aqueous-based liquid. The microcapsules of the present invention may advantageously be incorporated into personal care or household care compositions, but are preferably incorporated into personal care compositions. The home care composition is preferably an aqueous laundry detergent or an aqueous fabric conditioner. The composition is preferably a skin cleansing composition containing a cleansing surfactant.

Typically, the composition comprises microcapsules at a level of from 0.001% to 10%, more preferably from 0.005% to 7.55%, even more preferably from 0.01 to 5%, most preferably from 0.1% to 2% by weight of the total composition.

The composition preferably comprises a cleansing surfactant. More than one cleansing surfactant may be included in the composition. The cleansing surfactant may be selected from the group consisting of soaps, non-soap anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, and mixtures thereof. Many suitable surfactants are available and are fully described in the literature, e.g., "Surface-Active Agents and Detergents" by Schwartz, Perry and Berch, volumes I and II. Preferred surface-active compounds which may be used are soaps, non-soap anionic surfactants, nonionic surfactants, amphoteric surfactants or mixtures thereof.

Suitable non-soap anionic surfactants include linear alkylbenzene sulphonates, primary and secondary alkyl sulphates, especially C₈To C₁₅Primary alkyl sulfates; alkyl ether sulfates; olefin sulfonates; alkylxylene sulfonate; a dialkyl sulfosuccinate salt; fatty acid ester sulfonates; or mixtures thereof. Sodium salts are generally preferred. The most preferred non-soap anionic surfactant is linear alkylbenzene sulphonate, especially having C₈To C₁₅Linear alkylbenzene sulfonates of alkyl chain length of (a). Preferably if it is by weight of the total compositionThe linear alkylbenzene sulphonate content is from 0 wt% to 30 wt%, more preferably from 1 wt% to 25 wt%, most preferably from 2 wt% to 15 wt%.

Nonionic surfactants which may be used include primary and secondary alcohol ethoxylates, especially C ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol₈To C₂₀Aliphatic alcohols, more particularly C ethoxylated with an average of 1 to 10 moles of ethylene oxide per mole of alcohol₁₀To C₁₅Primary and secondary fatty alcohols. Non-ethoxylated nonionic surfactants include alkyl polyglycosides, glycerol monoethers, and polyhydroxyamides (glucamides). It is preferred if the level of nonionic surfactant is from 0 wt% to 30 wt%, preferably from 1 wt% to 25 wt%, most preferably from 2 wt% to 15 wt%, by weight of the fully formulated composition comprising the microcapsules of the invention.

Suitable amphoteric surfactants are preferably betaine surfactants. Examples of suitable amphoteric surfactants include, but are not limited to, alkyl betaines, alkyl amido betaines, alkyl sultaines, and alkyl amido sultaines; preferably, those having from 8 to about 18 carbons in the alkyl and acyl groups. Preferably, the amount of amphoteric surfactant is from 0 to 20% by weight, more preferably from 1 to 10% by weight, based on the weight of the composition.

It is also possible to include certain mono-alkyl cationic surfactants. Cationic surfactants which may be used include those of the formula R¹R²R³R⁴N⁺X^-Wherein the R group is a long or short hydrocarbon chain, typically an alkyl, hydroxyalkyl or ethoxylated alkyl group, and X is a counterion (e.g., wherein R is¹Is C₈-C₂₂Alkyl, preferably C₈-C₁₀Or C₁₂-C₁₄Alkyl radical, R²Is methyl, and R which may be the same or different³And R⁴A compound that is methyl or hydroxyethyl); and cationic esters (e.g., choline esters).

Water-soluble skin benefit agents may optionally be formulated into the compositions of the present invention. A wide variety of water-soluble skin benefit agents may be used and levels may range from 0.1 to 50%, but preferably from 1 to 30% by weight of the composition. These materials include, but are not limited to, polyhydric alcohols. Preferred water-soluble skin benefit agents are glycerin, sorbitol, and polyethylene glycol.

Water-insoluble skin benefit agents may also be formulated into the compositions as conditioners and moisturizers. Examples include silicone oils; hydrocarbons such as liquid paraffin, petrolatum, microcrystalline wax and mineral oil; and vegetable triglycerides, such as sunflower seed oil and cottonseed oil.

Some compositions may comprise a thickening agent. These may be selected from the group consisting of cellulosics, natural gums, and acrylic polymers, but are not limited to these thickener types. Wherein the cellulose is sodium carboxymethylcellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose and their combination. Suitable gums include xanthan gum, pectin, karaya gum (karaya), agar gum, alginate gum, and combinations thereof. Among the acrylic thickeners are homopolymers and copolymers of acrylic and methacrylic acids, including carbomers such as Carbopol 1382, Carbopol 982, Ultrez, Aqua SF-1, and Aqua SF-2 available from Lubrizol Corporation. The amount of thickener may range from 0.01 to 3% by weight of the active polymer (other than solvent or water) in the composition.

Preservatives may desirably be incorporated into the compositions of the present invention to protect against the growth of potentially harmful microorganisms. Suitable conventional preservatives for use in the compositions of the present invention are alkyl esters of p-hydroxybenzoic acid. Other preservatives that have recently begun to be used include hydantoin derivatives, propionate salts, and a wide variety of quaternary ammonium compounds. Particularly preferred preservatives are phenoxyethanol, methyl paraben, propyl paraben, imidazolidinyl urea, sodium dehydroacetate and benzyl alcohol. The preservative should be selected having regard to the use of the composition and possible incompatibilities between the preservative and other ingredients. The preservative is preferably used in an amount ranging from 0.01% to 2% by weight of the composition.

A wide variety of other optional materials may be formulated into the composition. These may include: antimicrobial agents, such as 2-hydroxy-4, 2 ', 4 ' -trichlorodiphenyl ether (triclosan), 2, 6-dimethyl-4-hydroxychlorobenzene and 3,4,4 ' -trichlorocarbanilide (trichlorocarbanilide); scouring and exfoliating particles such as polyethylene and silica or alumina; cooling agents, such as menthol; skin sedatives, such as aloe vera; and a colorant.

In addition, the composition of the present invention may further comprise 0.5 to 10% by weight of a chelating agent such as tetrasodium Ethylenediaminetetraacetate (EDTA), EHDP or a mixture; opacifiers and pearlescers such as ethylene glycol distearate, titanium dioxide or Lytron621 (styrene/acrylate copolymer); which can all be used to enhance the appearance or performance of the product.

Preferably, the composition comprises water in an amount of at least 5%, more preferably at least 25%, even more preferably from 40 to 90% by weight of the composition and still even more preferably from 60 to 85% by weight of the composition.

The following examples are provided to facilitate an understanding of the present invention. The examples are not intended to limit the scope of the claims.