CN117813153A - Degradable delivery particles based on amine-containing natural materials - Google Patents

Abstract

An improved delivery particle comprising a benefit agent core and a shell encapsulating the core, and methods of forming such delivery particles and articles are described. The shell is the reaction product of: i) Isocyanate or acid chloride or acrylate with ii) an amine-containing natural material having a free amino moiety, and iii) an α, β -unsaturated compound forming a C-N covalent bond with the amine moiety of the natural material. The delivery particles of the present invention have improved release characteristics and enhanced degradation characteristics in OECD test method 301B.

Description

Degradable delivery particles based on amine-containing natural materials

Technical Field

The present invention relates to a capsule manufacturing process and biodegradable delivery particles produced by such process, the delivery particles comprising: a core material and a shell encapsulating the core.

Background

Microencapsulation is a process in which droplets, solid particles or gas are encapsulated within a solid shell, and are typically in the micrometer size range. The core material is separated from the surrounding environment by a shell. Microencapsulation technology has a wide range of commercial applications for different industries. In summary, the capsule is capable of providing one or more of the following functions: (i) providing stability to the formulation or material via mechanical separation of the incompatible components, (ii) protecting the core from the surrounding environment, (iii) masking or covering the undesirable properties of the active ingredient, and (iv) controlling or triggering the release of the active ingredient for a specific time or to a specific location. All of these attributes lead to an increase in the shelf life of several products and stabilization of the active ingredient in the liquid formulation.

Different microencapsulation methods and exemplary methods and materials are set forth in the following documents: schwantes (U.S. Pat. No. 6,592,990), nagai et al (U.S. Pat. No. 4,708,924), baker et al (U.S. Pat. No. 4,166,152), wojciak (U.S. Pat. No. 4,093,556), matsukawa et al (U.S. Pat. No. 3,965,033), ozono (U.S. Pat. No. 4,588,639), irgarshi et al (U.S. Pat. No. 4,610,927), brown et al (U.S. Pat. No. 4,552,811), scher (U.S. Pat. No. 4,285,720), jahns et al (U.S. Pat. Nos. 5,596,051 and 5,292,835), matson (U.S. Pat. No. 3,516,941), foris et al (U.S. Pat. No. 4,001,140;4,087,376;4,089,802 and 4,100,103), greene et al (U.S. Pat. No. 2,800,458;2,800, 2,730,456), clark (U.S. Pat. No. 6,531,156), hoyford et al (U.S. Pat. No. 4,221,710), hayford (U.S. Pat. No. 26, 4,444,699, sterbk et al (U.S. 4,463) and U.S. Pat. No. 4,37, U.S. 4,463, 37, U.S. Pat. 4,37, 4 to the book, 4-7, 37, and "U.S. Pat. No. 4,37", and "U.S. No. 4,37", U.S. 4,4 ", and" U.S. Pat. 6 ", and" U.S. Pat. 4 ".

Core-shell encapsulation can be used to protect active ingredients, such as benefit agents, from harsh environments and to release them at desired times, which can be well incorporated into the encapsulation during or after use. Among the various mechanisms that may be used to release the beneficial agent from the encapsulate, one mechanism that is commonly relied upon is to mechanically rupture the capsule shell by friction or pressure. As a release mechanism, the choice of mechanical rupture constitutes another challenge for the manufacturer, since the rupture must occur at a specific desired time, even though the capsule experiences mechanical stress before the desired release time.

Industry concerns about encapsulation technology have prompted the development of several polymer encapsulation chemistries that attempt to meet the requirements of biodegradability, low shell permeability, high deposition, targeted mechanical properties, and fracture curves. Increased environmental concerns have placed polymer capsules under supervision, so manufacturers have begun to investigate sustainable schemes for encapsulating benefit agents.

Biodegradable materials are present and can form delivery particles via agglomeration, spray drying, or phase inversion precipitation. However, delivery particles formed using these materials and techniques are highly porous and are not suitable for aqueous compositions containing surfactants or other carrier materials because the benefit agent is prematurely released into the composition.

There are non-leakage and performance delivering particles in the surfactant-based aqueous composition, but they are not biodegradable due to their chemical nature and cross-linking.

Encapsulation can be used in different fields such as pharmaceuticals, personal care, textiles, food, coatings, and agriculture. In addition, the primary challenge faced in encapsulation is the need to keep the encapsulated active ingredient completely within the capsule throughout the supply chain until a controlled or triggered release of the core material is applied. Such microencapsulation techniques are very limited and can meet the stringent standards of long-term retention and active ingredient protection capability that are commercially desirable, especially when small molecules are initially encapsulated.

There is a need for a delivery particle that is biodegradable and yet has high structural integrity to reduce leakage and resist damage from harsh environments.

Definition of the definition

As used herein, references to the term "(meth) acrylate" or "(meth) acrylic" are understood to refer to the specified monomers, oligomers, and/or prepolymers in both acrylate and methacrylate form (e.g., isobornyl (meth) acrylate "means both isobornyl methacrylate and isobornyl acrylate, similarly references to alkyl esters of (meth) acrylic means both alkyl esters of acrylic acid and alkyl esters of methacrylic acid, similarly references to poly (meth) acrylate means both polyacrylate and polymethacrylate are possible). Similarly, the expression "prepolymer" is used to indicate that the mentioned materials may be present as prepolymers or as oligomers and combinations of prepolymers. Similarly, it will be understood that references herein generally to (meth) acrylates or (meth) acrylates such as "water soluble (meth) acrylates", "aqueous (meth) acrylates" and the like are intended to cover or include (meth) acrylate monomers and/or oligomers. Furthermore, when referring to certain (meth) acrylate monomers and/or oligomers or initiators, the descriptions "water-soluble or water-dispersible", "water-soluble" and "water-dispersible" mean that the specified components are soluble or dispersible in the given matrix solution itself or in the presence of suitable solubilizers or emulsifiers or by reaching certain temperatures and/or pH.

Unless otherwise indicated, each alkyl moiety herein may be selected from C ₁ -C ₈ Or even C ₁ -C ₂₄ . Poly (meth) acrylate materials are intended to include a broad spectrum of polymeric materials including, for example, polyester poly (meth)) Acrylates, urethanes and polyurethane poly (meth) acrylates (especially those prepared by reacting hydroxyalkyl (meth) acrylates with polyisocyanates or urethane polyisocyanates), methyl cyanoacrylate, ethyl cyanoacrylate, diethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene glycol di (meth) acrylate, allyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylate functional silicones, di, tri and tetraethylene glycol di (meth) acrylates, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, di (pentamethylene glycol) di (meth) acrylate, vinyl di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethoxylated bisphenol a di (meth) acrylate, diglycerol di (meth) acrylate, tetraethylene glycol dichloro acrylate, 1, 3-butanediol di (meth) acrylate, neopentyl di (meth) acrylate, polyethylene glycol di (meth) acrylate and dipropylene glycol di (meth) acrylate and various polyfunctional (meth) acrylates and polyfunctional (meth) acrylates. Monofunctional acrylates, i.e. those containing only one acrylate group, may also be advantageously used. Typical monomeric acrylates include 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, cyanoethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, p-dimethylaminoethyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, chlorobenzyl (meth) acrylate, aminoalkyl (meth) acrylate, various alkyl (meth) acrylates and glycidyl (meth) acrylate. Of course, mixtures of (meth) acrylates or their derivatives and combinations of one or more (meth) acrylate monomers, oligomers and/or prepolymers or their derivatives with other copolymerizable monomers, including acrylonitrile and methacrylonitrile, may also be used. The multifunctional (meth) acrylate monomer will typically have at least 2, at least 3 and preferably at least 4, at least 5 or even at least 6 polymerizable functional groups.

For ease of reference in this specification and claims, as used herein in reference to structural materials forming delivery particle wall polymers, the term "monomer" is understood to be a monomer, but also includes oligomers and/or prepolymers formed from the particular monomer.

As used herein, the term "water-soluble material" means a material that has a solubility in water of at least 0.5% at 60 ℃.

As used herein, the term "oil soluble" means a material that has a solubility in the core of interest of at least 0.1% at 50 ℃.

As used herein, the term "oil-dispersible" means that at least 0.1% of the material can be dispersed in the core of interest at 50 ℃ and no aggregates are visible.

Disclosure of Invention

A delivery particle is described that includes a core material and a shell encapsulating the core material. The core material may comprise a benefit agent. The shell comprises a polymer. More specifically, the polymer comprises the reaction product of:

i) Isocyanate or acid chloride or oil-soluble di-or multifunctional (meth) acrylate, with

ii) an amine-containing natural material having a free amino moiety, and

iii) An α, β -unsaturated compound, the α, β -unsaturated compound forming a C-N covalent bond with an amine moiety of the natural material. The weight percent of isocyanate to amine-containing natural materials and α, β -unsaturated compounds is from 0.1:90:9.9 to 20:10:70 based on the weight of the polymer.

The α, β -unsaturated compounds form C-N covalent bonds with the amino groups of the natural polymer. The natural material may be selected from chitosan, chitin, gelatin, amine-containing starch, amino sugar, polylysine or hyaluronic acid. Without being limited by theory, the C-N covalent bond is formed via a conjugated nucleophilic addition reaction (including N-nucleophile), such as a free amino moiety on the natural polymer and an electron-deficient olefin molecule such as an α, β -unsaturated ester.

The α, β -unsaturated compound may be selected from water-soluble or water-dispersible acrylates, methacrylates, alkyl acrylates, α, β -unsaturated esters, acrylic acid, acrylamides, vinyl ketones, vinyl sulfones, vinyl phosphonates, acrylonitrile derivatives, or mixtures thereof. For clarity, water-soluble or water-dispersible acrylates will generally be distinguished from oil-soluble di-or multifunctional acrylates. In some cases, similar materials may be used for each phase.

Water solubility or water dispersibility is the ability to dissolve or disperse in water. The water-soluble material typically has a solubility in water of at least 0.01g/100ml water at 25 ℃, or even greater than 0.03g/100ml water, but typically greater than 1g/100cc. By water-dispersibility is meant that the material is dispersed at least 0.1% without visible aggregates.

In general, the oil-soluble monomers are soluble or dispersible in the oil phase, typically at least to the extent of 0.1g in 100ml of oil, or dispersible or emulsifiable therein at 50 ℃.

In embodiments, the α, β -unsaturated compound is a monofunctional, difunctional, or polyfunctional polymer compound or mixtures thereof. The α, β -unsaturated compound may be selected to be anionically charged. Alternatively, the α, β -unsaturated compound may be cationically charged.

The zeta potential of the delivery particles is-100 mV to +200mV at pH 3 and-200 mV to +100mV at pH 10.

The free amino moiety of a portion of the natural material reacts with the α, β -unsaturated compound via an Aza-Michael addition reaction. In addition, a portion of the free amino moiety of the natural material reacts with isocyanate, acid chloride or (meth) acrylate to form urea, amide or amino ester linkages, respectively.

In embodiments in which a portion of the free amino moiety of the natural material is reacted with an isocyanate, the isocyanate may be selected from the group consisting of a polyisocyanate of toluene diisocyanate, a trimethylolpropane adduct of xylylene diisocyanate, methylene diphenyl isocyanate, toluene diisocyanate, tetramethyl dimethyl aniline diisocyanate, naphthalene-1, 5-diisocyanate, and phenylene diisocyanate.

In embodiments where a portion of the free amino moiety of the natural material is reacted with an acid chloride, the acid chloride may be selected from terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, 1,3, 5-benzenetricarbonyl trichloride, adipoyl dichloride, glutaryl dichloride or sebacoyl dichloride.

In embodiments in which a portion of the free amino moieties of the natural material are reacted with an oil-soluble (meth) acrylate, the oil-soluble (meth) acrylate is selected from the group consisting of difunctional (meth) acrylates, trifunctional (meth) acrylates, tetrafunctional (meth) acrylates, pentafunctional (meth) acrylates, hexafunctional (meth) acrylates, heptafunctional (meth) acrylates, and mixtures thereof. The oil-soluble multifunctional (meth) acrylate may be a multifunctional acrylate or methacrylate monomer or oligomer or prepolymer, and may include di, tri, tetra, penta, hexa, hepta, or octafunctional acrylates, methacrylates, and multifunctional urethane acrylates.

The α, β -unsaturated water-soluble or water-dispersible acrylate may be selected from ester-based acrylates, ethylene glycol-based acrylates, propylene glycol-based acrylates, amino ester-based acrylates.

Ester-based acrylates:

ethylene glycol based acrylates:

propylene glycol based acrylates:

amino ester-based acrylates:

m＝1-6；n＝1-200；q＝0-24

wherein R is as shown in structure V:

the α, β -unsaturated water-soluble or water-dispersible acrylates used for illustration may include, but are not limited to, 2-carboxyethyl acrylate oligomer, 2-carboxypropyl acrylate, 4-acryloxyphenylacetic acid, carboxyoctyl acrylate, tripropylene glycol diacrylate, ethoxylated bisphenol diacrylate, dipropylene glycol diacrylate, alkoxylated hexanediol diacrylate, alkoxylated cyclohexane dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, trimethylol propane triacrylate, pentaerythritol triacrylate, ethoxylated trimethylol propane triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glyceryl triacrylate, di (trimethylolpropane) tetraacrylate, dipentaerythritol pentaacrylate, ethoxylated pentaerythritol tetraacrylate, tri (meth) acrylate glycerol, ethylene glycol diacrylate, di, tri, tetra or pentaethylene glycol diacrylate, dipropylene glycol diacrylate, polyethylene glycol diacrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl (meth) acrylate, cyanoethyl acrylate, 2-hydroxypropyl acrylate, lauryl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl (meth) amino ethyl (meth) acrylate, amino ethyl (meth) amino (meth) acrylate, dimethylaminoethyl (meth) acrylate, alone or in combination.

The oil-soluble or oil-dispersible multifunctional (meth) acrylate monomers and oligomers comprise two or more double bonds, preferably two or more acrylate or methacrylate functional groups. Suitable monomers and oligomers include, by way of example and not limitation, allyl methacrylate; triethylene glycol dimethacrylate; ethylene glycol dimethacrylate; diethylene glycol dimethacrylate; aliphatic or aromatic urethane acrylates, such as hexafunctional aromatic urethane acrylates; ethoxylated aliphatic difunctional urethane methacrylates; aliphatic or aromatic urethane methacrylates, such as tetrafunctional aromatic methacrylates; epoxy acrylate; epoxy methacrylate; tetraethylene glycol dimethacrylate; polyethylene glycol dimethacrylate; 1, 3-butanediol diacrylate; 1, 4-butanediol dimethacrylate; 1, 4-butanediol diacrylate; diethylene glycol diacrylate; 1, 6-hexanediol diacrylate; 1, 6-hexanediol dimethacrylate; neopentyl glycol diacrylate; polyethylene glycol diacrylate; tetraethylene glycol diacrylate; triethylene glycol diacrylate; 1, 3-butanediol dimethacrylate; tripropylene glycol diacrylate; ethoxylated bisphenol a diacrylate; ethoxylated bisphenol a dimethacrylate; dipropylene glycol diacrylate; alkoxylated hexanediol diacrylate; alkoxylated cyclohexanedimethanol diacrylate; propoxylate neopentyl glycol diacrylate; trimethylolpropane trimethacrylate; trimethylolpropane triacrylate; pentaerythritol triacrylate; pentaerythritol tetramethyl acrylate; ethoxylated trimethylolpropane triacrylate; propoxylated trimethylolpropane triacrylate; propoxylated glyceryl triacrylate; di (trimethylolpropane) tetraacrylate; dipentaerythritol pentaacrylate; ethoxylated pentaerythritol tetraacrylate; bisphenol a diacrylate; bisphenol a dimethacrylate, hexafunctional aromatic urethane acrylate; a hexafunctional aromatic urethane methacrylate; alone or in combination.

In embodiments, the core containing the benefit agent is a perfume, preferably a perfume comprising perfume raw materials characterized by a log P of about 2.5 to about 4.5. The core may additionally comprise a partitioning regulator selected from isopropyl myristate, vegetable oils, modified vegetable oils, C ₄ -C ₂₄ Monoesters, diesters and triesters of fatty acids, laurylbenzophenone, laurate, methyl behenate, methyl laurate, methyl palmitate, methyl stearate and mixtures thereof, preferably isopropyl myristate.

In certain embodiments, the wall has a 60 day biodegradation rate according to the OECD 301B test of greater than 30% co ₂ Preferably greater than 40% CO ₂ More preferably above 50% CO ₂ Even more preferably above 60% CO ₂ 。

Optionally or alternatively, the wall of the delivery particle further comprises a coating material, preferably wherein the coating material is selected from the group consisting of poly (meth) acrylates, poly (ethylene-maleic anhydride), polyamines, waxes, polyvinylpyrrolidone copolymers, polyvinylpyrrolidone-ethyl acrylate, polyvinylpyrrolidone-vinyl acrylate, polyvinylpyrrolidone methacrylate, polyvinylpyrrolidone/vinyl acetate, polyvinyl acetal, polyvinyl butyral, polysiloxanes, poly (propylene maleic anhydride), maleic anhydride derivatives, copolymers of maleic anhydride derivatives, polyvinyl alcohol, styrene-butadiene latex, gelatin, gum arabic, carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, other modified celluloses, sodium alginate, chitosan, chitin, casein, pectin, modified starches, polyvinyl acetal, polyvinyl butyral, polyvinyl methyl ether/maleic anhydride, polyvinylpyrrolidone and copolymers thereof, poly (vinylpyrrolidone/methacrylamidopropyl trimethylammonium chloride), polyvinylpyrrolidone/vinyl acetate, polyvinylpyrrolidone/vinyl pyrrolidone/methyl acrylamide, polyvinyl amine copolymers, polyvinyl amine copolymers thereof, polyvinyl amine copolymers thereof.

The present invention also describes a method of forming a population of delivery particles comprising a core material and a shell encapsulating the core material, wherein the core material comprises a benefit agent; and wherein the shell comprises a polymer comprising the reaction product of:

i) Isocyanate or acid chloride or di-or multifunctional (meth) acrylate, with

ii) an amine-containing natural material having a free amino moiety, and

iii) An alpha, beta-unsaturated compound,

the method comprises the following steps:

i) Forming an aqueous phase comprising dissolving or dispersing an amine-containing natural material in water;

ii) mixing together the following components to form an oil phase: a benefit agent, preferably a perfume, optionally a partitioning modifier, and optionally a solvent, together with a shell-forming material selected from the group consisting of isocyanate, acid chloride and oil-soluble di-or multifunctional (meth) acrylate;

iii) Emulsifying the oil phase in the aqueous phase to form an emulsion and heating the emulsion;

iv) adding to the emulsion an alpha, beta-unsaturated compound comprising a water-soluble or water-dispersible acrylate, alkyl acrylate, alpha, beta-unsaturated ester, acrylic acid, acrylamide, vinyl ketone, vinyl sulfone, vinyl phosphonate or acrylonitrile derivative, and mixing the emulsion and the alpha, beta-unsaturated compound together,

v) the α, β -unsaturated compound forms a C-N covalent bond with a portion of the amine groups of the natural material.

The α, β -unsaturated compound undergoes a conjugated addition with a nucleophile (i.e., free amine groups of the amine-containing natural material). The α, β -unsaturated compound is electron deficient at the unsaturated bond. This conjugated addition of nucleophiles to electron-deficient unsaturation results in the formation of C-N covalent bonds with a portion of the amine groups of the natural material.

Free amines of amine-containing natural materials react as nucleophiles by mixing, microwave-assisted or heating, covalently bonding at the unsaturated sites of the α, β -unsaturated compounds.

The leakage rate of the delivered particles was less than about 50% as determined by the leakage rate test described in the test methods section.

In further constructions, the delivery particles of the present invention may be made into new articles by incorporation into different articles. Such articles may be selected from the group consisting of agricultural formulations, slurries encapsulating the agriculturally active ingredient, dry microcapsule populations encapsulating the agriculturally active ingredient, agricultural formulations encapsulating the pesticide and agricultural formulations for delivering the pre-emergent herbicide. The agriculturally active ingredient may be selected from the group consisting of agricultural herbicides, agricultural pheromones, agricultural pesticides, agricultural nutrients, insect control agents and plant stimulants.

Drawings

Figure 1 shows the measured zeta potential of an encapsulate according to the invention.

Detailed Description

A delivery particle is described that includes a core material and a shell encapsulating the core material. The core material may comprise a benefit agent. The shell comprises a polymer. More specifically, the polymer comprises the reaction product of:

i) Isocyanate or acid chloride or acrylate, with

ii) an amine-containing natural material having a free amino moiety, and

iii) An α, β -unsaturated compound, the α, β -unsaturated compound forming a C-N covalent bond with an amine moiety of the natural material. The weight percent ratio of the isocyanate to amine-containing natural material and alpha, beta-unsaturated compound is from 0.1:90:9.9 to 20:10:70 based on the weight of the polymer.

The α, β -unsaturated compounds form C-N covalent bonds with the free amino groups of the natural polymer. The natural material is selected from chitosan, chitin, gelatin, amine-containing starch, amino sugar, polylysine or hyaluronic acid.

By way of example and not limitation, the α, β -unsaturated compound may be selected from water-soluble or water-dispersible acrylates, methacrylates, alkyl acrylates, α, β -unsaturated esters, acrylic acid, acrylamides, vinyl ketones, vinyl sulfones, vinyl phosphonates, acrylonitrile derivatives, or mixtures thereof. Specific examples of α, β -unsaturated compounds useful in the present invention include α, β -unsaturated esters, including: alpha, beta-unsaturated carboxylic acid esters and acrylic or methacrylic acid esters. Exemplary acrylamides include: acrylamide, methacrylamide, n-isopropylacrylamide, (3-acrylamidopropyl) trimethylammonium chloride, 2-acrylamido-2-methyl-1-propanesulfonic acid. Exemplary vinyl ketones include: vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone, vinyl isopropyl ketone. The alpha, beta-unsaturated compounds may include vinyl sulfones, vinyl phosphonates and acrylonitrile derivatives.

To produce the delivery particles of the present invention, an aqueous phase is prepared that comprises an aqueous solution or dispersion of an amine-containing natural material having free amino moieties. The amine-containing natural material is a bio-based material. Such materials include, for example, chitosan. The amine-containing natural material is dispersed in water. In the case of chitosan, the material is hydrolyzed, thereby protonating at least a portion of the amine groups and promoting dissolution in water. Hydrolysis is carried out by heating at an acidic pH, e.g., about 5 or 5.5, for a period of time.

The hydrolyzed amine-containing natural material solution is then used in a first reaction with isocyanate or acid chloride or oil-soluble di-or multifunctional (meth) acrylate. This is accomplished by preparing an oil phase containing: a core material comprising a benefit agent and an isocyanate or acid chloride or oil-soluble di-or multifunctional (meth) acrylate forming a shell. When the oil phase is combined with the aqueous phase under high shear agitation, an emulsion is formed. The emulsion is heated, for example, to about 60-95 ℃, or even 60-80 ℃, or even 70-80 ℃, which initiates the reaction with the oil phase isocyanate or acid chloride or oil soluble di-or multifunctional (meth) acrylate. As the reaction proceeds, a second crosslinker comprising an α, β -unsaturated compound is added to the emulsion. The α, β -unsaturated compounds form C-N covalent bonds with the amine moiety of the natural material. The α, β -unsaturated compound is added as a first emulsion or during emulsification, but a portion of the amine remains available for crosslinking with the added α, β -unsaturated compound.

The α, β -unsaturated compound is selected from water-soluble or water-dispersible materials, such as a second acrylate. The water-soluble or water-dispersible material may be an acrylate, alkyl acrylate, or alpha, beta-unsaturated ester, or acrylic acid, acrylamide, vinyl ketone, vinyl sulfone, vinyl phosphonate, acrylonitrile derivative, or mixtures thereof. The α, β -unsaturated compound comprises an additional shell forming material, i.e. a shell forming material from the aqueous phase, and is a second cross-linking agent.

The invention may be exemplified using, for example, gelatin as the natural material. In one embodiment, to produce the delivery particles of the present invention, an aqueous phase is prepared that comprises an aqueous solution or dispersion of an amine-containing natural material having free amino moieties. The amine-containing natural material is selected to be a bio-based material. Such material may for example comprise gelatin, such as bovine gelatin of type B. The amine-containing natural material is dispersed in water by heating at 50 ℃. After dissolution, the solution was cooled to about 25 ℃. The oil phase is prepared with a perfume and optionally a partitioning regulator such as isopropyl myristate, and an isocyanate or an acid chloride or an oil-soluble di-or multifunctional (meth) acrylate. The oil phase is added to the aqueous phase under high shear milling to form an emulsion. Water-soluble or water-dispersible acrylates, alkyl acrylates, alpha, beta-unsaturated esters, acrylic acid, acrylamides, vinyl ketones, vinyl sulfones, vinyl phosphonates, acrylonitrile derivatives or mixtures of the foregoing are added. For example, the water-soluble or water-dispersible α, β -unsaturated compound may be trimethylolpropane triacrylate, as described in the specific examples herein.

Gelatin is reacted with isocyanate or acid chloride or oil-soluble di-or multifunctional (meth) acrylates. This is accomplished by preparing an oil phase containing: a core material comprising a benefit agent and a shelled isocyanate or acyl chloride or oil-soluble di-or multifunctional (meth) acrylate. When the oil phase is combined with the aqueous phase under high shear agitation, an emulsion is formed. The emulsion is heated, for example, to about 60-95 ℃, or even 60-80 ℃, or even 70-80 ℃, which initiates the reaction with the oil phase isocyanate or acid chloride or oil soluble di-or multifunctional (meth) acrylate. As the reaction proceeds, a second crosslinker comprising an α, β -unsaturated compound is added to the emulsion. The α, β -unsaturated compound forms a C-N covalent bond with the amine moiety of gelatin. The α, β -unsaturated compound is added as a first emulsion or during emulsification, but a portion of the amine remains available for crosslinking with the added α, β -unsaturated compound.

The α, β -unsaturated compound is selected from water-soluble or water-dispersible materials such as acrylates, alkyl acrylates, or α, β -unsaturated esters, or acrylic acid, acrylamides, vinyl ketones, vinyl sulfones, vinyl phosphonates, acrylonitrile derivatives, or mixtures thereof. The α, β -unsaturated compound comprises an additional shell forming material, i.e. a shell forming material from the aqueous phase, and is a second cross-linking agent.

The oil phase is prepared by dissolving a polymer of isocyanate (or alternatively acid chloride or polyfunctional (meth) acrylate) such as a trimer of Xylylene Diisocyanate (XDI) or Methylene Diphenyl Isocyanate (MDI) in an oil at 25 ℃. Diluents such as isopropyl myristate may be used to adjust the hydrophilicity of the oil phase. The oil phase is then added to the aqueous phase and high speed milling is performed to achieve the target size. The emulsion is then cured in one or more heating steps, for example heating to 40 ℃ for 30 minutes and holding at 40 ℃ for 60 minutes. The time and temperature are approximate. The temperature and time are selected to be sufficient to form and solidify the shell at the interface of the oil phase droplets and the water continuous phase. For example, the emulsion is heated to 85 ℃ over 60 minutes and then held at 85 ℃ for 360 minutes to cure the capsule. The slurry was then cooled to room temperature.

The volume weighted median particle size of the delivery particles according to the present invention may be from 5 microns to 150 microns, or even from 10 to 50 microns, preferably from 15 to 50 microns.

Isocyanates which can be used according to the invention are understood to be those which are used for the purposes of this application as isocyanate monomers, isocyanate oligomers, isocyanate prepolymers, or dimers or trimers of aliphatic or aromatic isocyanates. All such monomers, prepolymers, oligomers, or dimers or trimers of aliphatic or aromatic isocyanates are intended to be included in the term "isocyanate" as used herein.

Isocyanates are aliphatic or aromatic monomers, oligomers or prepolymers, usefully two or more isocyanate functional groups. The isocyanate may be selected, for example, from aromatic toluene diisocyanate and its derivatives, or aliphatic monomers, oligomers or prepolymers, such as hexamethylene diisocyanate and its dimers or trimers, or 3, 5-trimethyl-5-isocyanatomethyl-1-isocyanatocyclohexane tetramethylene diisocyanate, for use in the wall formation of the encapsulate. The polyisocyanate may be selected from 1, 3-diisocyanato-2-methylbenzene, hydrogenated MDI, bis (4-isocyanatocyclohexyl) methane, dicyclohexylmethane-4, 4' -diisocyanate, and oligomers and prepolymers thereof. This list is exemplary and is not intended to limit the polyisocyanates useful in the present invention.

Isocyanates useful in the present invention comprise isocyanate monomers, oligomers or prepolymers, or dimers or trimers thereof, having at least two isocyanate groups. Optimal crosslinking can be achieved with isocyanates having at least three functional groups.

In the context of the present invention, isocyanate is understood to include any isocyanate monomer, oligomer, prepolymer or polymer having at least two isocyanate groups and containing aliphatic or aromatic moieties in the monomer, oligomer or prepolymer. If aromatic, the aromatic moiety may comprise a phenyl, toluoyl, xylyl, naphthyl or diphenyl moiety, more preferably a toluoyl or xylyl moiety. For its purposes, aromatic polyisocyanates may include diisocyanate derivatives such as biurets and polyisocyanurates. The polyisocyanate, when aromatic, may be, but is not limited to, methylene diphenyl isocyanate, toluene diisocyanate, tetramethyl dimethylaniline diisocyanate, polyisocyanate esters of toluene diisocyanate (under the trade name RC is commercially available from Bayer), trimethylol propane adduct of toluene diisocyanate (under the trade name +.>L75 commercially available from Bayer), or trimethylolpropane adducts of xylylene diisocyanate (under the trade name +.>D-110N is commercially available from Mitsui Chemicals), naphthalene-1, 5-diisocyanate and phenylene diisocyanate.

Isocyanates, which are aliphatic, are understood to be monomeric, oligomeric, prepolymer or polymeric polyisocyanates which do not contain any aromatic moieties. While aromatic polyisocyanates are preferred, aliphatic polyisocyanates and blends thereof are also useful. Aliphatic polyisocyanates include trimers of hexamethylene diisocyanate, trimers of isophorone diisocyanate, trimethylolpropane adducts of hexamethylene diisocyanate (available from Mitsui Chemicals) or biurets of hexamethylene diisocyanate (under the trade nameN100 is commercially available from Bayer).

The capsule shell may also be reinforced with additional co-crosslinking agents such as polyfunctional amines and/or polyamines such as Diethylenetriamine (DETA), polyethyleneimine and polyvinylamine.

Core(s)

The microcapsules of the present invention comprise a benefit agent comprising one or more ingredients intended to be encapsulated. The benefit agent is selected from a number of different materials such as chromogens and dyes, flavors, fragrances, sweeteners, odorants, oils, fats, pigments, cleaning oils, pharmaceuticals, medicinal oils, fragrance oils, mold inhibitors, antibacterial agents, fungicides, bactericides, disinfectants, binders, phase change materials, odorants, fertilizers, nutrients and herbicides: by way of example, and not limitation. The benefit agent and oil comprise the core. The core may be liquid or solid. When using cores that are solid at ambient temperature, the wall material may usefully not completely encase the entire core for certain applications where it is desirable to utilize an aggregate core, for example, when in use. Such uses may include scent release, cleansing compositions, emollients, cosmetic delivery, and the like. In the case where the microcapsule core is a phase change material, the use may include using such encapsulated materials in mattresses, pillows, bedding, textiles, sports equipment, medical devices, building products, construction products, HVAC, renewable energy, clothing, sports fields, electronics, automotive, aerospace, footwear, cosmesis, laundry and solar energy.

The core constitutes the material that is microencapsulated. Typically, especially when the core material is a liquid material, the core material is combined with one or more compositions from which the microcapsule inner walls are formed or solvents for the benefit agent or partitioning modifier. If the core material can act as an oil solvent in the capsule, for example as a wall forming material or a solvent or carrier for the benefit agent, a majority of the material of the core material can be encapsulated, or if the carrier itself is a benefit agent, the entire material can be encapsulated. However, typically the benefit agent is from 0.01 to 99% by weight of the capsule contents, preferably from 0.01 to about 65% by weight of the capsule contents, more preferably from 0.1 to about 45% by weight of the capsule contents. In some applications, the core material may be effective even in only trace amounts.

In cases where the benefit agent itself is insufficient to act as an oil phase or solvent, particularly for wall forming materials, the oil phase may comprise a suitable carrier and/or solvent. In this regard, the oil is optional, as the benefit agent itself may sometimes be an oil. These carriers or solvents are typically oils, preferably having a boiling point greater than about 80 ℃, and are low volatile and nonflammable. Although not limited thereto, they preferably comprise one or more esters, preferably having a chain length of up to 18 carbon atoms or even up to 42 carbon atoms and/or triglycerides such as C ₆ -C ₁₂ Esters of fatty acids and glycerol. Exemplary carriers and solvents include, but are not limited to: ethyl diphenyl methane; isopropyl diphenyl ethane; butyl biphenyl ethane; benzyl xylene; alkyl biphenyls such as propyl biphenyls and butyl biphenyls; dialkyl phthalates such as dibutyl phthalate, dioctyl phthalate, dinonyl phthalate and ditridecyl phthalate; 2, 4-trimethyl-1, 3-pentanediol diisobutyrate; alkylbenzenes such as dodecylbenzene; alkyl or aralkyl benzoates such as benzyl benzoate; diaryl ethers; di (aralkyl) ethers and aryl aralkyl ethers; ethers such as diphenyl ether, dibenzyl ether and phenylbenzyl ether; liquid higher alkyl ketones (having at least9 carbon atoms); alkyl or aralkyl benzoates, such as benzyl benzoate; alkylated naphthalenes such as dipropylnaphthalene; partially hydrogenated terphenyl; high boiling linear or branched hydrocarbons; alkylaryl hydrocarbons such as toluene; vegetable oils and other crop oils such as canola oil, soybean oil, corn oil, sunflower oil, cottonseed oil, lemon oil, olive oil and pine oil; methyl esters of fatty acids derived from transesterification of vegetable oils and other crop oils, methyl esters of oleic acid, esters of vegetable oils such as soybean oil methyl esters, aliphatic hydrocarbons of linear paraffins, and mixtures of the foregoing.

Useful benefit agents include perfume raw materials such as alcohols, ketones, aldehydes, esters, ethers, nitriles, olefins, fragrances, odorant solubilizers, essential oils, phase change materials, lubricants, colorants, coolants, preservatives, antibacterial or antifungal actives, herbicides, antiviral actives, preservative actives, antioxidants, bioactive ingredients, deodorants, emollients, humectants, exfoliants, ultraviolet absorbers, self-healing compositions, corrosion inhibitors, opacifiers, silicone oils, waxes, hydrocarbons, higher fatty acids, essential oils, lipids, skin coolants, vitamins, opacifiers, antioxidants, glycerin, catalysts, bleach particles, silica particles, malodor reducing agents, dyes, brighteners, antibacterial actives, antiperspirant actives, cationic polymers, and mixtures thereof. Phase change materials that may be used as benefit agents may include, by way of example and not limitation, alkanes having 13-28 carbon atoms, various hydrocarbons such as n-octacosane, n-heptacosane, n-hexacosane, n-pentacosane, n-tetracosane, n-tricosane, n-docosane, n-heneicosane, n-eicosane, n-nonadecane, octadecane, n-heptadecane, n-hexadecane, n-pentadecane, n-tetradecane, n-tridecane. Alternatively, the phase change material may optionally additionally comprise crystalline materials such as 2, 2-dimethyl-1, 3-propanediol, 2-hydroxymethyl-2-methyl-1, 3-propanediol, acids of straight or branched chain hydrocarbons such as eicosanoids and esters such as methyl palmitate, fatty alcohols and mixtures thereof.

Preferably, in the case of fragrances, the fragrance oil acts as a benefit agent and solvent for the wall forming material, as described in the examples herein.

Optionally the aqueous phase may comprise an emulsifier. Non-limiting examples of emulsifiers include water-soluble salts of: alkyl sulfates, alkyl ether sulfates, alkyl isosulfates, alkyl carboxylates, alkyl sulfosuccinates, alkyl sulfates such as sodium dodecyl sulfate, alkyl sarcosinates, alkyl derivatives of protein hydrolysates, acyl aspartate, alkyl or alkylaryl ether phosphates, sodium dodecyl sulfate, phospholipids or lecithins, or soaps, sodium, potassium or ammonium salts of stearates, oleates or palmitates, alkylaryl sulfonates such as sodium dodecyl benzene sulfonate, sodium dialkyl sulfosuccinates, dioctyl sulfosuccinates, sodium dilauryl sulfosuccinates, sodium poly (styrene sulfonate) salts, isobutylene-maleic anhydride copolymers, gum arabic, sodium alginate, carboxymethyl cellulose, cellulose sulfate and gum, poly (styrene sulfonate), isobutylene-maleic anhydride copolymers, carrageenan, sodium alginate, pectic acid, tragacanth gum, almond gum and agar; semisynthetic polymers such as carboxymethyl cellulose, cellulose sulfate, methyl cellulose sulfate, carboxymethyl starch, starch phosphate, lignin sulfonic acid; and synthetic polymers such as maleic anhydride copolymers (including hydrolysates thereof), polyacrylic acid, polymethacrylic acid, acrylic acid-butyl acrylate copolymers or crotonic acid homopolymers and copolymers, vinylbenzenesulfonic acid or 2-acrylamido-2-methylpropanesulfonic acid homopolymers and copolymers, and the meta-amides or meta-esters of these polymers and copolymers, carboxy-modified polyvinyl alcohols, sulfonic acid-modified polyvinyl alcohols and phosphoric acid-modified polyvinyl alcohols, phosphoric acid or tristyrylphenol ethoxylates, palmitoylaminopropyl trimethylammonium chloride (Varisoft PATC ^TM Degussa Evonik, available from Exsen, germany), distearyldimethyl ammonium chloride, cetyltrimethylammonium chloride, quaternary ammonium compounds, fatty amines, aliphatic ammonium halides, alkyl dimethylbenzyl ammonium halides, alkyl dimethylethyl ammonium halides, polyethyleneimines, poly (2-dimethylamino) ethyl methacrylate) methyl chloride quaternary salts, poly (l-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylateAcid ester), poly (acrylamide-co-diallyldimethylammonium chloride), poly (allylamine), quaternized poly [ bis (2-chloroethyl) ether-alternating-1, 3-bis [3- (dimethylamino) propyl ]]Urea]And poly (dimethylamine-co-epichlorohydrin-co-ethylenediamine), condensation products of aliphatic amines with alkylene oxides, quaternary ammonium compounds having long chain aliphatic groups such as distearyl ammonium dichloride, and aliphatic amines, alkyl dimethylbenzyl ammonium halides, alkyl dimethylethyl ammonium halides, polyalkylene glycol ethers, condensation products of alkylphenols, aliphatic alcohols or fatty acids with alkylene oxides, ethoxylated alkylphenols, ethoxylated aryl phenols, ethoxylated polyarylphenols, polyol-solubilized carboxylic esters, polyvinyl alcohol, polyvinyl acetate, or polyvinyl alcohol-polyvinyl acetate copolymers, polyacrylamides, poly (N-isopropylacrylamide), poly (2-hydroxypropyl methacrylate), poly (-ethyl-2-oxazoline), poly (2-isopropenyl-2-oxazoline-co-methyl methacrylate), poly (methyl vinyl ether) and poly (vinyl alcohol-co-ethylene), and cocoamidopropyl betaine. The emulsifier, if used, is typically about 0.1 to 40 weight percent, preferably 0.2 to about 15 weight percent, more typically 0.5 to 10 weight percent, based on the total weight of the formulation.

In addition to the benefit agent, the microcapsules may encapsulate the partitioning modifier. Non-limiting examples of partitioning modifiers include isopropyl myristate, C ₄ -C ₂₄ Monoesters, diesters, and triesters of fatty acids, castor oil, mineral oil, soybean oil, hexadecanoic acid, methyl ester isododecane, isoparaffin oil, polydimethylsiloxane, brominated vegetable oils, and combinations thereof. Microcapsules may also have different ratios of partitioning modifier to benefit agent to produce different microcapsule populations, which may have different bloom patterns. Such populations may also incorporate different perfume oils so that the microcapsule populations exhibit different bloom patterns and different scent experiences. Other non-limiting examples of microcapsules and partitioning modifiers are disclosed in US2011-0268802 and are incorporated herein by reference.

Optionally, if desired, the delivery particles may be dehydrated, for example, by decantation, filtration, centrifugation, or other separation techniques. Alternatively, the aqueous slurry delivery particles may be spray dried.

In some examples of the methods and compositions, the microcapsules may be composed of one or more distinct populations. The composition may have at least two different microcapsule populations that differ in the exact composition and median particle size of the perfume oil and/or the weight ratio of partitioning modifier to perfume oil (PM: PO). In some examples, the composition comprises more than two different clusters, which differ in the exact composition of the fragrance oils and their burst strength. In some further examples, the population of microcapsules is different in the weight ratio of partitioning modifier to perfume oil. In some examples, the composition may comprise a first population of microcapsules (having a first ratio, i.e., a 2:3 to 3:2 weight ratio, of partitioning modifier to first perfume oil) and a second population of microcapsules (having a second ratio, i.e., less than 2:3 but greater than 0 weight ratio, of partitioning modifier to second perfume oil).

In some embodiments, each different population of microcapsules may be prepared in a different slurry. For example, a first population of microcapsules may be contained in a first slurry and a second population of microcapsules contained in a second slurry. It will be appreciated that there is no limit to the number of different slurries used for combining and the choice of formulator, so that 3, 10 or 15 different slurries can be combined. The first and second populations of microcapsules may be different in terms of the exact composition and median particle size of the perfume oil and/or the PM to PO weight ratio.

In some embodiments, the composition may be prepared by combining the first and second slurries with at least one adjunct ingredient, and optionally packaged in a container. In some examples, the first and second populations of microcapsules can be prepared in different slurries, and then spray dried to form the particles. The different slurries may be combined prior to spray drying or spray dried separately and then combined together when in particulate powder form. Once in powder form, the first and second populations of microcapsules can be combined with auxiliary ingredients to form a composition that can be used as a feedstock for the manufacture of consumer, industrial, medical, or other goods. In some examples, at least one population of microcapsules is spray dried and combined with a second population of microcapsules slurry. In some examples, at least one population of microcapsules is dried, which is prepared by spray drying, fluid bed drying, tray drying, or other such available drying methods.

In some examples, the slurry or dry particles may comprise one or more auxiliary materials such as processing aids selected from the group consisting of carriers, aggregation inhibiting materials, deposition aids, particulate suspension polymers, and mixtures thereof. Non-limiting examples of aggregation inhibiting materials include salts that will have a charge shielding effect around the particles, such as magnesium chloride, calcium chloride, magnesium bromide, magnesium sulfate, and mixtures thereof. Non-limiting examples of particulate suspension polymers include polymers such as xanthan gum, carrageenan, guar gum, shellac, alginate, chitosan; cellulosic materials such as carboxymethyl cellulose, hydroxypropyl methyl cellulose, cationically charged cellulosic materials; polyacrylic acid; polyvinyl alcohol; hydrogenated castor oil; ethylene glycol distearate; and mixtures thereof.

In some embodiments, the slurry may comprise one or more processing aids selected from water, aggregation inhibiting materials such as divalent salts; particulate suspending polymers such as xanthan gum, guar gum, carboxymethyl cellulose.

In other examples of the invention, the slurry may comprise one or more carriers selected from the group consisting of: polar solvents including, but not limited to, water, ethylene glycol, propylene glycol, polyethylene glycol, glycerol; non-polar solvents including, but not limited to, mineral oils, perfume raw materials, silicone oils, hydrocarbon paraffinic oils, and mixtures thereof.

In some examples, the slurry may comprise a deposition aid, which may comprise a polymer selected from the group consisting of: polysaccharides, in one aspect, cationically modified starches and/or cationically modified guar gums; a polysiloxane; polydiallyl dimethyl ammonium halide; a copolymer of polydiallyl dimethyl ammonium chloride and polyvinylpyrrolidone; a composition comprising polyethylene glycol and polyvinylpyrrolidone; an acrylamide; imidazole; halogenated imidazole salts; polyvinyl amine; copolymers of polyvinylamine and N-vinylformamide; polyvinyl formamide, polyvinyl alcohol; boric acid crosslinked polyvinyl alcohol; polyacrylic acid; polyglycerol ether silicone crosslinked polymer; polyacrylic acid, polyacrylate, copolymer of polyvinylamine and polyvinylalcohol oligomer of amine, on the one hand diethylenetriamine, ethylenediamine, bis (3-aminopropyl) piperazine, N-bis (3-aminopropyl) methylamine, tris (2-aminoethyl) amine and mixtures thereof; polyethyleneimine, a derivatized polyethyleneimine, on the one hand ethoxylated polyethyleneimine; a polymer compound comprising at least two moieties selected from carboxylic acid moieties, amine moieties, hydroxyl moieties and nitrile moieties, polyisoprene, polybutadiene/styrene, polybutadiene/acrylonitrile, carboxy-terminated polybutadiene/acrylonitrile, or combinations thereof, on a polybutadiene backbone; preformed aggregates of a combination of anionic surfactant and cationic polymer; polyamines and mixtures thereof.

In some further examples to illustrate the invention, at least one population of microcapsules may be contained in an aggregate, then combined with a different population of microcapsules and at least one auxiliary material. The aggregate may comprise a material selected from the group consisting of: silica, citric acid, sodium carbonate, sodium sulfate, sodium chloride, and binders such as sodium silicate, modified cellulose, polyethylene glycol, polyacrylate, polyacrylic acid, zeolite, and mixtures thereof.

Suitable devices for use in the processes disclosed herein may include continuous stirred tank reactors, homogenizers, turbine agitators, recirculation pumps, blade mixers, plow shear mixers, ribbon mixers, vertical axis granulator and drum mixers, both in batch and, where applicable, in continuous process configurations, spray dryers, and extruders. Such devices are available from Lodige GmbH (padbo en, germany), littleford Day, inc. (florasy, kentucky), forberg AS (norway larvelvety), glatt Ingenieurtechnik GmbH (emam, germany), niro (Soeborg, denmark), hosokawa Bepex corp. (minneapolis, minnesota, usa), arde barinc (new jersey, usa).

Test method

Procedure for determining% degradation

Percent degradation was determined by "OECD Guideline for Testing of Chemicals"301B CO formally passing 7.17 1992 ₂ Evolution (modified Sturm test) was measured. For ease of reference, this test method is referred to herein as test method OECD 301B.

Procedure for determination of free oil

This method measures the amount of oil in the aqueous phase and uses 1mg/ml dibutyl phthalate (DBP)/hexane as an internal standard solution.

A small amount of DBP greater than 250mg was weighed into a small beaker and transferred to a 250ml volumetric flask, which was thoroughly rinsed. Fill with hexane to 250ml.

Sample preparation: about 1.5-2g (40 drops) of the capsule slurry was weighed into a 20ml scintillation vial and 10ml of ISTD solution was added and the lid was closed. The solution was pipetted into an autosampler vial with vigorous shaking several times within 30 minutes and analyzed by GC.

Additional details. Instrument: connecting HP 5890GC to HP Chem Station Software; chromatographic column: 5m 0.32mm inside diameter, 1 μm DB-1 liquid phase; the temperature is 50 ℃;1 minute, then heated to 320 ℃; @5 ℃/min; a syringe: 275 deg.c; a detector: 325 deg.c; 2 μl was injected.

And (3) calculating: the total peak area minus the DBP area is summed for both the sample and the correction.

i) Mg of free core oil was calculated:

ii) calculating the free core oil%

Procedure for determining leakage rate of benefit agent

2 portions of a 1 gram sample composition of benefit agent particles were obtained. 1 gram (sample 1) of the particle composition was added to 99g of the product matrix in which the particles were to be used. The product matrix containing the particles (sample 1) was aged in a sealed glass jar at 35 ℃ for 2 weeks. An additional 1 gram of sample (sample 2) was similarly aged.

After 2 weeks, filtration was used to recover the particles of the particle composition from the product matrix (sample 1) and the particle composition (sample 2). Each particle sample is treated with a solvent that will extract all of the benefit agent from each sample particle. The solvent containing the benefit agent from each sample was injected into the gas chromatograph and the peak area was integrated to determine the total amount of benefit agent extracted from each sample.

The percent benefit agent leakage was determined as follows: the difference obtained by subtracting the total amount of benefit agent extracted from sample 1 from the total amount of benefit agent extracted from sample 2 was calculated and expressed as a percentage of the total amount of benefit agent extracted from sample 2 as shown in the following equation:

delivery particles may be prepared that exhibit a positive zeta potential. Such capsules have improved deposition efficiency, for example, on fabrics.

Sample preparation for biodegradation rate measurement

The water-soluble or water-dispersible material is purified via crystallization until a purity of greater than 95% is achieved and dried prior to measuring the biodegradation rate.

Extraction of the oily medium containing the benefit agent from the slurry of delivery particles is required to analyze only the polymer wall. Thus, the delivery particle slurry is freeze-dried to obtain a powder. It is then further washed with an organic solvent via a Soxhlet extraction method to extract the benefit agent-containing oily medium until the weight percent of oily medium is less than 5% based on total delivered particle polymer walls. Finally, the polymer wall was dried and analyzed.

The weight ratio of delivery particles to solvent was 1:3. The residual oily medium was determined by thermogravimetric analysis (isothermal for 60 minutes at 100 ℃ C. And isothermal for another 60 minutes at 250 ℃ C.). The measured weight loss needs to be less than 5%.

OECD 301B-biodegradation rate method

Test No.301 according to the economic Cooperation and development Organization (OECD) guidelines-OECD (1992): ready Biodegradability OECD guidelines for testing chemicals, section 3, OECD publications, paris, https: the cumulative CO was measured over 60 days in the case of// doi. Org/10.1787/9789264070349-en ₂ Releasing.

Leakage rate

The amount of benefit agent leaked from the benefit agent-containing delivery particles was determined according to the following method:

i) Two samples of 1g of a feedstock slurry containing benefit agent-containing delivery particles were obtained.

ii) 1g of the raw stock slurry containing benefit agent delivery particles was added to 99g of the consumer product substrate for which the particles were to be used, and this mixture was labeled as sample 1. A second 1g sample of the raw material particle slurry was immediately used in step d below, in its pure form, without contact with the consumer product substrate, and was labeled sample 2.

iii) The product matrix containing the delivery particles (sample 1) was aged in a sealed glass jar at 35 ℃ for 1 week.

iv) recovering particles from both samples using filtration. The particles in sample 1 (in the consumer product matrix) were recovered after the aging step. The particles (pure raw stock slurry) in sample 2 were recovered at the same time as the aging step of sample 1 was started.

v) treating the recovered particles with a solvent to extract the benefit agent material from the particles.

vi) analyzing the solvent from each sample containing the extracted benefit agent via chromatography.

vii) integrating the area of the beneficial agent peaks formed under the curve and summing these areas to determine the total amount of beneficial agent extracted from each sample.

viii) the percentage of benefit agent leakage is determined as follows: the difference obtained by subtracting the total amount of benefit agent extracted from sample 1 (S1) from the total amount of benefit agent extracted from sample 2 (S2) is calculated as a percentage of the total amount of benefit agent extracted from sample 2 (S2), as shown in the following equation:

volume weighted average particle size

Particle size is measured using a static light scattering device such as an Accusizer 780A manufactured by Particle Sizing Systems, santa Barbara Calif. The instrument was calibrated from 0 to 300 μ using Duke particle size criteria. If the volume weighted average particle size of the emulsion is to be determined, the sample for particle size evaluation is prepared by diluting about 1g of the emulsion, or if the final particle volume weighted average particle size is to be determined, 1g of the benefit agent containing delivery particle slurry is diluted in about 5g deionized water and about 1g of this solution is further diluted in about 25g water.

About 1g of the most diluted sample was added to the Accusizer and the test was started using the autodilution feature. The Accusizer should read more than 9200 counts/second. If the number is less than 9200, additional samples should be added. The Accusizer will dilute the test sample until 9200 counts/sec and begin the evaluation. After 2 minutes of testing, the Accusizer will display the results, including the volume weighted average size.

The breadth index can be calculated by determining the particle size of more than 95% of the cumulative particle volume (95% particle size), the particle size of more than 5% of the cumulative particle volume (5% particle size), and the median particle size (50% particle size-50% of the particle volume being above and below this particle size). Width index= ((95% particle size) - (5% particle size)/50% particle size).

All percentages and ratios are by weight unless otherwise indicated. All percentages and ratios are calculated based on the total composition unless otherwise indicated.

It should be understood that each maximum numerical limitation presented throughout this specification includes each numerical lower limit as if such numerical lower limits were expressly recited herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Each numerical range given throughout this specification will include each and every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.

In the examples which follow, the abbreviations correspond to the materials listed in Table 1.

TABLE 1

Examples

Example 1 crosslinked chitosan capsules Using isocyanate and acrylate Cross-linking Agents

A chitosan stock solution was prepared by dispersing 121.50g chitosan in 2578.5g deionized water while mixing in a jacketed reactor. The chitosan dispersion was then pH adjusted to 5.12 with 48.60g of concentrated HCl under stirring. The chitosan solution was then warmed to 85 ℃ over 60 minutes and then held at 85 ℃ for a period of time to hydrolyze ChitoClear. The temperature was reduced to 25℃over a period of 90 minutes after the hydrolysis step. The pH of the hydrolyzed chitosan solution was 5.28. The resulting chitosan stock solutions were used to prepare isocyanate and acrylate crosslinked chitosan capsules in examples 1, 2, 8 and 9.

The aqueous phase was prepared by mixing 308.70g of the chitosan stock solution described above in a jacketed reactor. An oil phase was prepared by mixing 102.64g fragrance and 25.66g isopropyl myristate with 2.80g Takenate D-110N at room temperature. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion having the desired particle size. The emulsion was heated to 70 ℃. Then 7.21g of trimethylolpropane triacrylate was slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 43.80 microns. The free oil of the formed capsule was 0.19% and the leakage rate was 14.20% for one week.

EXAMPLE 2 Chitosan Capsule crosslinked with isocyanate and acrylate Cross-linking agent

The aqueous phase was prepared by mixing 308.70g of the chitosan stock solution described above in a jacketed reactor. An oil phase was prepared by mixing 102.64g fragrance and 25.66g isopropyl myristate with 2.80g Takenate D-110N at room temperature. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion having the desired particle size. The emulsion was heated to 70 ℃. Then 10.82g of trimethylolpropane triacrylate was slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 38.80 microns. The free oil of the formed capsule was 0.28% and the leakage rate was 14.94% for one week.

EXAMPLE 3 gelatin capsules crosslinked with isocyanate and acrylate crosslinkers

The aqueous phase was prepared by dissolving bovine gelatin of type 11.97g B with 225bloom in 187.60g deionized water in a jacketed reactor with mixing at 50 ℃. The aqueous phase was then cooled to 25 ℃ after the gelatin was dissolved. An oil phase was prepared by mixing 102.64g fragrance and 25.66g isopropyl myristate with 2.80g Takenate D-110N at room temperature. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion having the desired particle size. The emulsion was heated to 70 ℃. Then 7.21g of trimethylolpropane triacrylate was slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 20.54 microns. The free oil of the formed capsule was 0.04%, and the leakage rate was 8.24% for one week.

EXAMPLE 4 gelatin capsules crosslinked with isocyanate and acrylate crosslinkers

The aqueous phase was prepared by dissolving bovine gelatin of type 11.97g B with 225bloom in 187.60g deionized water in a jacketed reactor with mixing at 50 ℃. The aqueous phase was then cooled to 25 ℃ after the gelatin was dissolved. An oil phase was prepared by mixing 102.64g fragrance and 25.66g isopropyl myristate with 2.80g Takenate D-110N at room temperature. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion having the desired particle size. The emulsion was heated to 70 ℃. Then a second acrylate crosslinker, 3.61g trimethylolpropane triacrylate and 5.25g CD 9055 from Sartomer, were slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 16.83 microns. The free oil of the formed capsule was 0.15% and the leakage rate was 52.98% for one week.

EXAMPLE 5 gelatin capsules crosslinked with isocyanate and acrylate crosslinkers

The aqueous phase was prepared by dissolving bovine gelatin of type 11.97g B with 225bloom in 227.50g deionized water in a jacketed reactor with mixing at 50 ℃. The aqueous phase was then cooled to 25 ℃ after the gelatin was dissolved. An oil phase was prepared by mixing 102.64g fragrance and 25.66g isopropyl myristate with 2.80g Takenate D-110N at room temperature. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion having the desired particle size. The emulsion was heated to 70 ℃. Then, 3.61g of trimethylolpropane triacrylate and 8.75g of an 80% solution of [2- (acryloyloxy) ethyl ] trimethylammonium chloride were slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 40.02 microns. The free oil of the formed capsule was 0.09%, and the leakage rate was 4.86% for one week.

EXAMPLE 6 gelatin capsules crosslinked with isocyanate and acrylate crosslinkers

A gelatin solution modified with cationic acrylates was prepared by mixing 40.35g of bovine gelatin, type B, 225bloom with 32.04g of an 80% solution of [2- (acryloyloxy) ethyl ] trimethylammonium chloride in 600g of deionized water at 70℃for 12 hours.

The aqueous phase was prepared by mixing 210g of the above cationic acrylate modified gelatin solution in a jacketed reactor at 25 ℃. An oil phase was prepared by mixing 102.64g fragrance and 25.66g isopropyl myristate with 2.80g Takenate D-110N at room temperature. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion having the desired particle size. The emulsion was heated to 70 ℃. Then 4.20g of trimethylolpropane triacrylate was slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 16.06 microns. The free oil of the formed capsule was 0.14% and the leakage rate was 30.16% for one week.

EXAMPLE 7 gelatin capsules crosslinked with isocyanate and acrylate crosslinkers

An anionic acrylate modified gelatin solution was prepared by mixing 39.48g of bovine gelatin, type B, 225bloom with 18.66g of CD9055 acrylate from Sartomer in 600g of deionized water at 70 ℃ for 12 hours.

The aqueous phase was prepared by mixing 210g of the above anionic acrylate modified gelatin solution in a jacketed reactor at 25 ℃. An oil phase was prepared by mixing 102.64g fragrance and 25.66g isopropyl myristate with 2.80g Takenate D-110N at room temperature. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion having the desired particle size. The emulsion was heated to 70 ℃. Then 4.20g of trimethylolpropane triacrylate was slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 43.43 microns. The free oil of the formed capsule was 0.09%, and the leakage rate was 44.77% for one week.

EXAMPLE 8 Chitosan capsules crosslinked with oil-phase acrylate and Water-phase acrylate Cross-linking Agents

The aqueous phase was prepared by mixing 234.60g of the chitosan stock solution of example 1 with 108.00g of deionized water and 3.46g of 5% Selvol 540 at 70 ℃. The oil phase was prepared by mixing 66.59g fragrance and 54.48g isopropyl myristate together with 8.82g SR368 from Sartomer in a jacketed reactor at 70 ℃. The aqueous phase was added to the oil phase at 70 ℃ without mixing. High shear is applied to the mixture after the addition of the entire aqueous phase to obtain an emulsion having the desired particle size. Then 6.18g of trimethylolpropane triacrylate was slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 32.11 microns. The free oil of the formed capsule was 0.16% and the leakage rate was 26.31% for one week.

EXAMPLE 9 Chitosan capsules crosslinked with oil-phase acrylate and Water-phase acrylate Cross-linking Agents

The aqueous phase was prepared by mixing 234.60g of the chitosan stock solution of example 1 with 108.00g of deionized water and 6.96g of 5% Selvol 540 at 70 ℃. The oil phase was prepared by mixing 66.59g fragrance and 54.48g isopropyl myristate with 7.26g CN975 from Sartomer at 70 ℃. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion of the desired particle size. Then 6.18g of trimethylolpropane triacrylate was slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 28.84 microns. The free oil of the formed capsule was 0.27% and the leakage rate was 18.90% for one week.

EXAMPLE 10 gelatin capsules crosslinked with oil phase acrylate and aqueous phase acrylate Cross-linking Agents

A gelatin solution was prepared by dissolving 20.58g type B bovine gelatin having 225bloom in 210.00g deionized water at 50 ℃ in a jacketed reactor with mixing. An aqueous phase was prepared by adding 4.90g of a 5% Selvol 540 solution to the above gelatin solution at 25 ℃. An oil phase was prepared by mixing 64.16g fragrance and 64.16g isopropyl myristate with 7.21g CN975 from Sartomer at 70 ℃. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion of the desired particle size. Then 7.21g of trimethylolpropane triacrylate was slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 22.82 microns. The free oil of the formed capsule was 0.99% and the leakage rate was 77.55% for one week.

EXAMPLE 11 gelatin capsules crosslinked with oil phase acrylate and aqueous phase acrylate Cross-linking Agents

A gelatin solution was prepared by dissolving 20.58g type B bovine gelatin having 225bloom in 210.00g deionized water at 50 ℃ in a jacketed reactor with mixing. 4.90g of a 5% Selvol 540 solution was added to the above gelatin solution at 25℃to prepare an aqueous phase. An oil phase was prepared by mixing 64.16g fragrance and 64.16g isopropyl myristate with 7.21g CN975 from Sartomer at 70 ℃. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion of the desired particle size. The second and third acrylate crosslinkers, 3.64g of trimethylolpropane triacrylate and 5.14g of tetra (glycol) diacrylate were then slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 23.36 microns. The free oil of the formed capsule was 0.25% and the leakage rate was 67.12% for one week.

EXAMPLE 12 gelatin capsules crosslinked with oil phase acrylate and aqueous phase acrylate Cross-linking Agents

The aqueous phase was prepared by dissolving 20.58g of type B bovine gelatin with 225bloom in 210.00g of deionized water at 50 ℃ in a jacketed reactor with mixing. The aqueous phase was then cooled to 25 ℃ after the gelatin was dissolved. An oil phase was prepared by mixing 64.16g fragrance and 64.16g isopropyl myristate with 7.21g CN975 from Sartomer at 70 ℃. The oil phase is added to the aqueous phase under high shear milling to obtain an emulsion of the desired particle size. The second and third acrylate crosslinkers, 3.64g of trimethylolpropane triacrylate and 5.14g of tetra (glycol) diacrylate were then slowly added to the emulsion with mixing. The emulsion obtained was then heated to 90 ℃ over 60 minutes and kept at this temperature for 8 hours while mixing. The median particle size of the formed capsules was 35.60 microns. The free oil of the formed capsule was 0.15% and the leakage rate was 66.67% for one week.

The percent degradation was measured by test method OECD 301B according to the guidelines for OECD for test chemicals. Copies were available at www.oecd-iligary.

The core to wall ratio of the capsule according to the invention may even be as high as 95% core to 1% wall weight ratio. In applications where an increased degradation rate is desired, a higher core to wall ratio may be used, such as 99% core to 1% wall, or even 99.5% to 0.5% or higher weight ratio. With a properly selected core to wall ratio, the shell of the composition according to the invention can be selected to achieve a degradation rate of at least 40% after 14 days, at least 50% after 20 days, and at least 60% after 28 days when tested according to the test method OECD 301B.

The use of the singular forms "a", "an" and "the" are intended to cover both the singular and the plural unless the context clearly dictates otherwise. The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms. All references, including publications, patent applications, and patents cited therein are incorporated herein by reference. Any description of certain embodiments as "preferred" embodiments, as well as other expressions which describe the embodiments, features or ranges as being preferred, or which are preferred suggestions, are not to be considered limiting. The present invention is considered to include embodiments which are presently considered to be less preferred and which are described herein as such. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended to illuminate the invention and does not pose a limitation on the scope of the invention. Any recitation herein of the nature or benefits of the present invention or preferred embodiments is not intended to be limiting. This invention includes all modifications and equivalents of the subject matter recited herein as permitted by the applicable law. Furthermore, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. The description herein of any reference or patent, even if written as "prior," is not intended to constitute an admission that such reference or patent may be used as prior art to the present invention. None of the statements of the claim claims should be considered as limiting the scope of the present invention. Any recitation or suggestion herein of certain features constituting components of the claimed invention is not intended to be limiting, unless it is reflected in the appended claims.

Claims (22)

1. A delivery particle comprising a core material and a shell encapsulating the core material, wherein the core material comprises a benefit agent; and

wherein the shell comprises a polymer comprising the reaction product of:

isocyanate or acid chloride or oil-soluble di-or multifunctional (meth) acrylate, with

Amine-containing natural materials having free amino moieties, and

an alpha, beta-unsaturated compound forming a C-N covalent bond with an amine moiety of the natural material,

the weight percent of isocyanate to amine-containing natural material to α, β -unsaturated compound is from 0.1:90:9.9 to 20:10:70 based on the weight of the polymer;

2. the delivery particle according to claim 1, wherein the alpha, beta-unsaturated compound forms a C-N covalent bond,

wherein the natural material is selected from chitosan, chitin, gelatin, amine-containing starch, amino sugar, polylysine or hyaluronic acid; and

wherein the α, β -unsaturated compound is selected from the group consisting of water-soluble or water-dispersible acrylates, alkyl acrylates, α, β -unsaturated esters, acrylic acid, acrylamides, vinyl ketones, vinyl sulfones, vinyl phosphonates, acrylonitrile derivatives, or mixtures thereof.

3. The delivery particle according to claim 2, wherein the α, β -unsaturated compound is a monofunctional, difunctional or polyfunctional polymer compound or a mixture thereof.

4. The delivery particle according to claim 2, wherein the α, β -unsaturated compound is selected from acrylamide, methacrylamide, n-isopropylacrylamide, (3-acrylamidopropyl) trimethylammonium chloride, or 2-acrylamido-2-methyl-1-propanesulfonic acid.

5. The delivery particle according to claim 1, wherein the α, β -unsaturated compound is anionically charged.

6. The delivery particle according to claim 1, wherein the α, β -unsaturated compound is cationically charged.

7. The delivery particle according to claim 1, wherein the zeta potential of the delivery particle is-100 mV to +200mV at pH 3 and-200 mV to +100mV at pH 10. The delivery particle according to claim 1, wherein additionally a portion of the free amino moieties of the natural material react with the α, β -unsaturated compound via an Aza-Michael addition reaction.

8. The delivery particle according to claim 1, wherein a portion of the free amino moiety of the natural material is additionally reacted with isocyanate, acid chloride or acrylate to form urea, amide or amino ester linkages, respectively.

9. The delivery particle according to claim 8, wherein the isocyanate is selected from the group consisting of a polyisocyanate of toluene diisocyanate, a trimethylolpropane adduct of xylylene diisocyanate, methylene diphenyl isocyanate, toluene diisocyanate, tetramethyl dimethyl aniline diisocyanate, naphthalene-1, 5-diisocyanate, and phenylene diisocyanate.

10. The delivery particle according to claim 8, wherein the acid chloride is selected from terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, 1,3, 5-benzenetricarbonyl trichloride, adipoyl dichloride, glutaryl dichloride, or sebacoyl dichloride.

11. The delivery particle according to claim 1, wherein the oil-soluble (meth) acrylate is selected from the group consisting of difunctional (meth) acrylates, trifunctional (meth) acrylates, tetrafunctional (meth) acrylates, pentafunctional (meth) acrylates, hexafunctional (meth) acrylates, heptafunctional (meth) acrylates, octafunctional (meth) acrylates, and mixtures thereof.

12. The delivery particle of claim 2, wherein the water-soluble or water-dispersible (meth) acrylate is independently selected from the group consisting of 2-carboxyethyl acrylate, 2-carboxyethyl acrylate oligomer, 2-carboxypropyl acrylate, 4-acryloxyphenylacetic acid, carboxyoctyl acrylate, tripropylene glycol diacrylate, ethoxylated bisphenol diacrylate, dipropylene glycol diacrylate, alkoxylated hexanediol diacrylate, alkoxylated cyclohexane dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, trimethylol propane triacrylate, pentaerythritol triacrylate, ethoxylated trimethylol propane triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glyceryl triacrylate, di (trimethylolpropane) tetraacrylate, dipentaerythritol pentaacrylate, ethoxylated pentaerythritol tetraacrylate, glyceryl tri (meth) acrylate, ethylene glycol di-, di, tri, tetra or pentaethylene glycol diacrylate, dipropylene glycol diacrylate, polyethylene glycol diacrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl (meth) acrylate, cyanoethyl acrylate, 2-hydroxy propyl acrylate, lauryl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, diethylaminoethyl (meth) amino ethyl (meth) acrylate, amino ethyl (meth) amino (meth) acrylate, dimethylaminoethyl (meth) acrylate or a combination of the foregoing.

13. The delivery particle according to claim 1, wherein the benefit agent is a perfume agent, preferably comprising a perfume agent characterized by a log p of from about 2.5 to about 4.5 perfume raw materials.

14. The delivery particle according to claim 1, wherein the core further comprises a partitioning modifier selected from the group consisting of: isopropyl myristate, vegetable oil, modified vegetable oil, C ₄ -C ₂₄ Monoesters, diesters, and triesters of fatty acids, laurylbenzophenone, laurate, methyl behenate, methyl laurate, methyl palmitate, methyl stearate, and mixtures thereof, preferably isopropyl myristate.

15. The delivery particle of claim 1, wherein the wall has a 60 day biodegradation rate of greater than 30% co according to the OECD 301B test ₂ Preferably greater than 40% CO ₂ More preferably above 50% CO ₂ Even more preferably above 60% CO ₂ (up to 95%).

16. Delivery particle according to claim 1, wherein the wall of the delivery particle further comprises a coating material, preferably wherein the coating material is selected from the group consisting of poly (meth) acrylates, poly (ethylene-maleic anhydride), polyamines, waxes, polyvinylpyrrolidone copolymers, polyvinylpyrrolidone-ethyl acrylate, polyvinylpyrrolidone-vinyl acrylate, polyvinylpyrrolidone methacrylate, polyvinylpyrrolidone/vinyl acetate, polyvinyl acetal, polyvinyl butyral, polysiloxanes, poly (propylene maleic anhydride), maleic anhydride derivatives, copolymers of maleic anhydride derivatives, polyvinyl alcohol, styrene-butadiene latex, gelatin, gum arabic, carboxymethyl cellulose, carboxymethyl hydroxyethyl cellulose, other modified celluloses, sodium alginate, chitosan, chitin, casein, gum, modified starches, polyvinyl acetal, polyvinyl butyral, polyvinyl methyl ether/maleic anhydride, polyvinyl pyrrolidone and copolymers thereof, poly (vinyl pyrrolidone/methacrylamidopropyl trimethyl ammonium chloride), polyvinyl pyrrolidone/vinyl acetate, polyvinyl pyrrolidone/dimethylaminoethyl methacrylate, polyvinyl amine, polyvinyl formamide, polyallylamine, copolymers of polyvinyl amine, and mixtures thereof.

17. The delivery particle according to claim 1, wherein the delivery particle has a leakage rate of less than about 50%, or at most about 50%, as determined by the leakage rate test described in the test methods section.

18. The delivery particle according to claim 1, wherein the volume weighted median particle size of the delivery particle is 5-150 microns, or even 10-50 microns, or even 15-50 microns.

19. A method of forming a population of delivery particles, the delivery particles comprising: a core material and a shell encapsulating the core material, wherein the core material comprises a benefit agent; and, wherein the shell comprises a polymer,

the polymer comprises the reaction product of:

i) Isocyanate or acid chloride or di-or multifunctional (meth) acrylate, with

ii) an amine-containing natural material having a free amino moiety, and

iii) An alpha, beta-unsaturated compound,

the method comprises the following steps:

i) Forming an aqueous phase comprising dissolving or dispersing an amine-containing natural material in water;

ii) mixing together the following components to form an oil phase: a benefit agent, preferably a perfume, optionally a partitioning modifier, and optionally a solvent, together with a shell-forming material selected from the group consisting of isocyanate, acid chloride and oil-soluble di-or multifunctional (meth) acrylate;

iii) Emulsifying the oil phase in the aqueous phase to form an emulsion and heating the emulsion to initiate formation of a polyurea, polyamide or polyaminoester shell between the free amino moieties on the natural polymer and isocyanate, acid chloride or polyfunctional (meth) acrylate, respectively;

iv) adding an alpha, beta-unsaturated compound comprising a water-soluble or water-dispersible acrylate, alkyl acrylate, alpha, beta-unsaturated ester, acrylic acid, acrylamide, vinyl ketone, vinyl sulfone, vinyl phosphonate or acrylonitrile derivative to the emulsion with mixing, grinding or heating while the shell is formed,

whereby the α, β -unsaturated compound forms a C-N covalent bond with a portion of the amine groups of the natural material.

20. An article incorporating the delivery particle of claim 1.

21. The article of manufacture of claim 20, wherein the article of manufacture is selected from the group consisting of an agricultural formulation, a slurry encapsulating an agriculturally active ingredient, a population of dry microcapsules encapsulating an agriculturally active ingredient, an agricultural formulation encapsulating an insecticide, and an agricultural formulation for delivering a pre-emergent herbicide.

22. The article of manufacture of claim 20, wherein the agriculturally active ingredient is selected from the group consisting of agricultural herbicides, agricultural pheromones, agricultural pesticides, agricultural nutrients, insect control agents and plant irritants.