Biodegradable microcapsules, methods of making and using the same

Abstract

The present invention provides biodegradable microcapsules that can encapsulate and retain cargo, such as lipophilic or hydrophobic core materials including fragrances, butters, essential oils or other oils; or oil-soluble ingredients; methods of making the biodegradable microcapsules and their use in various industries. The present invention also provides biodegradable shell materials that exhibit signs of biodegradation or non-persistence in water-based and / or soil or compost-based environments.

Description

Technical Field

[0001] This invention relates to biodegradable microcapsules that can encapsulate and retain cargo, such as lipophilic or hydrophobic core materials containing fragrances, butter, essential oils, or other oils; or oil-soluble components; methods for preparing said biodegradable microcapsules; and their applications in various industries. The invention also provides biodegradable shell materials that exhibit signs of biodegradation or non-persistence in aquatic and / or soil or compost-based environments. Background Technology

[0002] Typically, microcapsules (a) provide protection and stability for the active ingredient or component encapsulated within them; (b) promote, trigger, or control the release of the encapsulated active ingredient or component; (c) prolong the lifespan of the active ingredient; (d) reduce the threat of exposure; or (e) ensure that the encapsulated active ingredient can be easily disposed of, otherwise such active ingredient is toxic or difficult to handle.

[0003] Microcapsules have a core material comprising a lipophilic / hydrophobic compound surrounded by a polymer shell. The release rate of the core material and its diffusion through the capsule wall can generally be controlled by altering the wall composition and / or the degree of crosslinking of the wall (shell) material. Furthermore, the degree of crosslinking of the wall material directly affects the strength and properties of the microcapsule wall.

[0004] For example, a highly beneficial use of microcapsules is to prolong the release of fragrances, essential oils, or other lipophilic or oil-soluble components encapsulated within a polymer shell. Typically, technologies or materials used for encapsulating fragrances or similar molecules (goods) include melamine-formaldehyde, urea-formaldehyde, or polyurea / polyurethane technologies or acrylate technologies, with classic interfacial polymerization being the most common. Because these goods often strongly solubilize or plasticize many polymers and / or contain volatile or low-boiling-point components that are difficult to retain within the polymer shell, the walls of such polymer shells used for encapsulation are cross-linked networks of these polymers to ensure stability and durability in formulations using them, such as laundry / washing products, household cleaning products, hair care products, skin care products, etc. They are not designed to be biodegradable or to be non-durable in the environment they may eventually enter. There are some known examples of biodegradable polymers used for microcapsule shell walls. For example, they include polyesters or poly-β-amino esters or poly-β-thioesters. However, in most cases, they are not typically encapsulated with fragrances or essential oils or other solvated or plasticized lipophilic or oil-soluble components for use in such consumer products, and / or are not biodegradable in the relevant end media.

[0005] US Patent 8,287,849 (assigned to the Massachusetts Institute of Technology) and the scientific publication "Degradable Poly-β-amino esters: Synthesis, Characterization, and Self-Assembly with Plasmid DNA" (by Lynn, DM, Langer, R.) published in J. Am. Chem. Soc. 2000, 122, 44, 10761–10768 disclose that poly-β-amino esters are generally unstable in solutions over a wide pH range for hours to days and are biodegradable in physiological or biomedical environments, comprising compounds prepared by reacting a primary amine with a bis-(acrylate).

[0006] US Patent 8,557,231 (assigned to the Massachusetts Institute of Technology) describes a poly-β-amino ester synthesized in an organic solvent such as tetrahydrofuran (THF) or dichloromethane (DCM), and then, after separation, is considered suitable for use in a complex double-emulsion encapsulation process that typically also uses a solvent (which will be removed later) such as DCM to manufacture capsules for delivering drugs or drug-based active ingredients for short-term controlled release in a biomedical physiological setting.

[0007] US Patent 8,945,622 B2 (assigned to the Council of Scientific and Industrial Research CSIR) discloses a sustained-release composition for delivering an active pharmaceutical ingredient, comprising a polyester backbone having the formula P[A(x)B(y)C(z)] prepared from a diol (A), a dicarboxylic acid or anhydride (B), and a monomer (C) having unsaturated side-chain groups, wherein a graft polymer of polyacrylic acid or methacrylic acid chains is grafted onto the polyester backbone. The patent also describes a tablet manufacturing process.

[0008] US Patent Publication US 2003 / 0224060 (assigned to L'Oréal) discloses nanocapsules containing a specific target cargo of retinyl ester, which is described as a lipophilic active agent and has a water-insoluble coating, comprising at least one polyester polyol, wherein the pre-formulated polyester polyol is obtained by polycondensation of an aliphatic dicarboxylic acid or derivative with at least two alkyl diols, or with at least one alkyl diol and at least one hydroxyalkyl alkyl diol.

[0009] US Patent Publication US 2007 / 0009441 (assigned to Molecular Therapeutics Inc.) discloses the synthesis of nanoparticles and their use in the nanoscale (typically less than 200 nm) encapsulation of water-soluble drugs or water-insoluble active ingredients for pharmaceutical applications as solids. Biodegradability / biocompatibility in simulated physiological media is shown, and in one aspect, itaconic acid polyesters are used with specially added crosslinking agents to radically crosslink the itaconic acid polymer via an aqueous free radical initiator system.

[0010] US Patent Publication US 2020 / 164332 (assigned to Calyxia SAS) describes a complex multilayer microcapsule in which the polymer shell may contain esters, but it is prepared by a very complex dual emulsion process and uses free radical polymerized monomers or polymers and added crosslinking agents.

[0011] European patent application EP 0517669 A1 (assigned to Sandoz) discloses a method for microencapsulating agricultural chemicals by microencapsulating the agricultural chemicals in cross-linked polymer capsules that are partly polyester polymers. The method includes the steps of: (a) dissolving or suspending the agricultural chemicals in a non-aqueous liquid mixture comprising an unsaturated polyester resin and a vinyl monomer (preferably styrene); (b) emulsifying the solution or suspension in water to a desired particle size; and (c) cross-linking the unsaturated polyester resin with the vinyl monomer to produce microcapsules.

[0012] PCT Publication WO2017125395 (assigned to BASF SE) discloses a (in soil) "biodegradable" polyester capsule comprising a water-soluble core and an insecticide, wherein the capsule shell contains polyester, and the capsule core contains a water-soluble pesticide (and is therefore a hydrophilic core) and at least 10% by weight of water, based on the total weight of the capsule core. Furthermore, an acyl chloride is used in its practical application to ensure moderate temperatures and short reaction times for in-situ formation of the polyester in the presence of the cargo.

[0013] The scientific publication “Fragrance-containing microcapsules based on interfacial thiol-ene polymerization” (Liao et al.), published in J. Appl. Polym. Sci. 2016, 133, 43905 doi:10.1002 / App.43905, discloses fragrance capsules with poly-β-thioester shells, which are made using a classic interfacial polymerization route.

[0014] Such existing technologies have numerous drawbacks, including: (i) some technologies target water-soluble active ingredients and are therefore unsuitable for hydrophobic or lipophilic materials; (ii) few demonstrate or claim biodegradability or are designed for biodegradability, none demonstrate or claim biodegradability in ambient water environments or in relevant OECD tests; (iii) many use organic solvents for encapsulation, which presents problems when removing volatile goods and when used with volatile goods; and (iv) in cases where one reactive or catalytic component is in an aqueous phase and another in an oil phase, undesirable acyl chlorides must therefore be used (in the case of polyesters) to maintain low reaction temperatures and thus emulsion stability and relatively short reaction times (as the higher temperatures typically required for diacid-diol condensation reactions are). (This can destabilize the emulsion and lead to unsuccessful encapsulation and loss of fragrance components or similar goods), or (in the case of β-thioesters) require a large excess of undesirable reactants (such as water-soluble, odorous thiols), and / or require the use of undesirable solvents and their evaporation; some technologies self-generate polymer shell walls in the presence of goods via interfacial polymerization; and (v) when the finished product contains fragrances or oils or other plasticized goods, few technologies (if any) exhibit any ability to maintain storage stability, or when used in household or personal care applications, few technologies (if any) exhibit storage stability or usability in the final product formulation, which may have extreme pH values ​​or surfactants or salts or solvents or other additives that may plasticize or erode the shell walls.

[0015] Encapsulating lipophilic or hydrophobic cargoes in polymer shells that are biodegradable in water or other media and robust enough to contain the cargo (typically in water-based formulations for personal care, household, or other products) until release is triggered, required, and / or released in a gradual or controlled manner.

[0016] The inventors' current goal is to meet these standards and thus ensure the production of microcapsules with shell materials that are biodegradable or non-durable, particularly in aqueous media / channels, and that can retain hydrophobic or lipophilic cargoes, or volatile or plasticized or oil-soluble cargoes (such as fragrances or essential oils or other oils), and that are stable in product form before use. Summary of the Invention

[0017] We have unexpectedly discovered that volatile or plasticizing hydrophobic or lipophilic components (such as fragrances, oils, and other lipophilic goods) can be encapsulated within a robust, storage-stable polymer shell containing aliphatic esters and / or β-amino esters and / or β-thioester moieties in the polymer backbone and / or in the polymer branches and / or in the polymer crosslinking. Furthermore, through the associated polymer shell precursors and polymer structures (such as linear, branched, crystalline, or crosslinked polymers), such polymer shell systems can meet important biodegradability criteria, particularly in terms of biodegradability or non-persistence in surrounding aquatic environments such as seawater, river / surface water, effluent, and / or other water treatment process streams (e.g., activated sludge).

[0018] In one important aspect, this application covers microcapsules based on polymer shell walls having esters and / or β-amino esters and / or β-thioesters.

[0019] Therefore, this application provides a microcapsule comprising: (i) a lipophilic core; and (ii) a polymer microcapsule shell; wherein the polymer microcapsule shell comprises a polymer or a cross-linked polymer, the polymer or cross-linked polymer being an aliphatic polyester or a poly-β-amino ester or a poly-β-thioester, or a copolymer or terpolymer thereof, or a mixture thereof; wherein the microcapsule is storage stable and its polymer shell is biodegradable.

[0020] Another aspect of this application is to provide a method for preparing the microcapsules. Therefore, this application provides a method for preparing microcapsules, the method comprising: (a) preparing an oil-in-water emulsion (i) an oil phase and (ii) an aqueous phase, the oil phase comprising a polymer or prepolymer and at least one lipophilic core, the aqueous phase comprising at least one stabilizer or emulsifier; (b) optionally, adding at least one catalyst, at least one diluent, or at least one initiator to the oil phase; (c) optionally, heating the oil-in-water emulsion to a temperature of 25°C to 100°C under stirring; (d) forming a polymer microcapsule shell by cooling or by an in-situ oil-in-water reaction of the polymer or prepolymer; and (e) obtaining a core encapsulated in the polymer microcapsule shell; wherein the polymer or prepolymer formed is an aliphatic polyester or poly-β-amino ester or poly-β-thioester, or copolymers or terpolymers thereof, or combinations thereof.

[0021] Therefore, this application provides a method for preparing microcapsules, the method comprising: (a) preparing an oil-in-water emulsion of (i) an oil phase and (ii) an aqueous phase, the oil phase comprising a monomeric reactant and at least one lipophilic core, the aqueous phase comprising at least one stabilizer or emulsifier; (b) optionally adding at least one catalyst, diluent or at least one initiator to the oil phase or the aqueous phase; (c) forming the polymer microcapsule shell by in-situ oil-in-water polymerization of the monomeric reactant; and (d) obtaining a core encapsulated in the polymer microcapsule shell.

[0022] Therefore, this application provides a method for preparing microcapsules, the method comprising: a) preparing an oil-in-water emulsion of an oil phase and an aqueous phase, the oil phase comprising a bifunctional or polyfunctional acid, and a glycol or polyfunctional alcohol, cargo, optionally added diluent or solvent and / or heated, the aqueous phase comprising a stabilizer and / or other additives; b) adding a catalyst to one phase; c) forming a polymer capsule shell wall by in-situ oil-in-water polycondensation (esterification) polymerization of monomeric reactants or other precursors; and d) obtaining cargo encapsulated in polymer microcapsule shells.

[0023] Therefore, this application provides a method for preparing microcapsules composed of β-thioester and β-aminoester functional groups, the method comprising: (a) pre-reacting a bifunctional or polyfunctional amine with a bifunctional or polyfunctional acrylate; (b) preparing an oil-in-water emulsion of (i) an oil phase and (ii) an aqueous phase, the oil phase comprising the result or product of (a) and any remaining acceptor, mixed with a bifunctional or polyfunctional thiol and at least one lipophilic core, optionally mixed with a diluent, the aqueous phase comprising at least one stabilizer or emulsifier; (c) optionally adding at least one catalyst to the oil phase or the aqueous phase; (d) forming the polymer microcapsule shell wall by in-situ oil-in-water Michael addition polymerization of the donor and the acceptor reactant; and (e) obtaining a lipophilic core encapsulated in the polymer microcapsule shell. Attached Figure Description

[0024] Other embodiments of this application can be understood from the accompanying drawings.

[0025] Figure 1 The aliphatic polyester microcapsules of the present invention (201-13-1 0.95SA / 0.05IA / 1.00HD) containing 25% by weight of fragrance are shown as follows: (i, left) before pressure or friction is applied under a microscope slide; (ii, right) cargo release is shown after pressure or friction is applied.

[0026] Figure 2The dried aliphatic polyester microcapsules of the present invention (201-13-1) having a fragrance loading of about 25% by weight are: (i, left) dried, under a microscope slide; (ii, right) the same dried capsules are redispersed in water and crushed to release the cargo, under a microscope slide.

[0027] Figure 3 Optical micrographs showing the aliphatic polyester microcapsules of the present invention: capsules prepared with PLGA prepolymer / polymer—before and after crushing (Example 14).

[0028] Figure 4 Optical microscopic images of the microcapsules (210-26-1) of Example 17—before and after crushing under a microscope coverslip to show fragrance release (capsules prepared via in-situ Michael addition polymerization).

[0029] Figure 5 Optical microscopic images of the microcapsules (210-86-1) of Example 18—before and after crushing under a microscope coverslip to show fragrance release (capsules prepared via in-situ Michael addition polymerization).

[0030] Figure 6 Optical microscopic images of the microcapsules (210-91-1) of Example 19—before and after crushing under a microscope coverslip to show fragrance release (capsules prepared via in-situ Michael addition polymerization).

[0031] Figure 7 Optical microscopic images of the microcapsules (210-82-1) of Example 20—before and after crushing under a microscope coverslip to show fragrance release (capsules prepared via in-situ Michael addition polymerization).

[0032] Figure 8 Optical microscope images of microcapsules (215-52-1) of Example 22, with isophorone diamine and hexathiol as donors and tetraacrylate as acceptor, before and after crushing under a microscope coverslip to show fragrance release.

[0033] Figure 9 Optical microscope images of microcapsules (215-42-1) of Example 22, with hexamethylenediamine and hexathiol as donors and tetraacrylate as acceptors, before and after crushing under a microscope coverslip to show fragrance release.

[0034] Figure 10Optical microscope images of the microcapsules (215-55-1) of the embodiment, with TMPP diamine and trithiol (trimethylolpropane tri-(3-mercaptopropionate)) as donors, before and after crushing under a microscope coverslip to show fragrance release.

[0035] Figure 11 Optical micrographs of the spray-dried capsule (210-48-1) of Example 25 (a capsule prepared by Michael addition polymerization), before and after crushing to show the release of flavor.

[0036] Figure 12 Optical micrograph of microcapsules (215-42-1) containing the fragrance Sunburst fresh R14-3913, prepared from butanediol diacrylate, 4,4'-trimethylenedipiperidine, and pentaerythritol hexa(3-mercaptopropionate).

[0037] Figure 13 The sensory test results show the release of fragrance from the polyester microcapsules of the present invention compared to samples containing only fragrance (R14-3913).

[0038] Figure 14 The sensory test results indicate the release of flavorings from the microcapsules of the present invention (capsules prepared by Michael addition polymerization).

[0039] Figure 15 The sensory test results indicate the release of flavorings from other microcapsules of the present invention (capsules prepared by Michael addition polymerization).

[0040] Figure 16 Sensory test results showing the release of fragrance from other microcapsules of the present invention (prepared by Michael addition polymerization) (compared to fabric conditioners without fragrance (A) and with pure fragrance (B).

[0041] Figure 17 The use / absence of Vazo 67 (V67) as a free radical initiator controls the biodegradation of microcapsule shell materials via crosslinking / branching / chain extension of polyester prepolymers with reactive unsaturated groups.

[0042] Figure 18 This data represents the biodegradation of microcapsule shell materials prepared via in-situ oil-in-water Michael addition polymerization, with DCM as cargo, which was subsequently evaporated. The data show that various compositions of β-thioesters and β-amino-co-β-thioesters exhibited gradual, active, and sustained biodegradation over 40 days. Detailed Implementation

[0043] For physical-mechanical encapsulation methods, such as spray drying, particle size control is typically achieved by controlling the physical conditions under which the relevant processes are carried out. Before explaining in detail at least one aspect of the disclosed and / or claimed inventive concept, it should be understood that the disclosed and / or claimed inventive concept, in its application, is not limited to the details of the construction and arrangement of components or steps or methods set forth in the following description or shown in the accompanying drawings. The disclosed and / or claimed inventive concept can have other aspects or can be practiced or performed in various ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting.

[0044] Unless otherwise stated, the following terms as used in this disclosure shall be understood to have the following meanings.

[0045] Unless otherwise defined herein, technical terms used in connection with the disclosed and / or claimed inventive concepts shall have the meanings commonly understood by one of ordinary skill in the art. Furthermore, unless the context requires otherwise, singular terms shall include plural forms, and plural terms shall include singular forms.

[0046] Unless the context explicitly specifies or clearly implies otherwise, the singular forms “a,” “an,” and “the” include the plural forms. The terms “comprising” and “comprises of” include the more restrictive claims such as “consistently of” and “comprises of.”

[0047] For the purposes of the following detailed description, numbers representing the amounts of ingredients used, for example, in the specification and claims, except in any operational embodiment or where otherwise specified, should be understood to be modified in all cases by the term "about". The numerical parameters given in the specification and appended claims are approximate values ​​and may vary depending on the desired properties to be obtained in practicing the invention.

[0048] Unless otherwise specified, all percentages, parts, proportions and ratios used herein are based on the total weight of the composition. All such weights relating to the listed ingredients are based on the active ingredient level and therefore, unless otherwise specified, do not include solvents or byproducts that may be present in commercially available materials.

[0049] For all purposes, and to the extent consistent with the publication of this document, all publications, articles, papers, patents, patent publications and other references cited herein are incorporated herein in their entirety.

[0050] The term "at least one species" is to be understood to include one species as well as any number of more than one species, including but not limited to 1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 100 species, etc. The term "at least one species" can be extended to 100 or 1000 species or more, depending on the terms it connects to. Furthermore, the number of 100 / 1000 species should not be considered limiting, as lower or higher limits may also produce satisfactory results.

[0051] As used herein, the terms “comprising” (and any form of inclusion, such as “comprise” and “comprises”), “having” (and any form of having, such as “includes” and “include”), “including” (and any form of inclusion, such as “includes” and “include”), or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unstated elements or method steps.

[0052] The terms “core” and “cargo” used throughout the specification are inclusive and refer to the same components that form the microcapsule encapsulation portion.

[0053] The term "selected independently" means that when a group appears more than once in a structure, the group can be selected independently each time it appears.

[0054] As used herein, the term "polymer" refers to a compound comprising repeating structural units (monomers) linked by covalent chemical bonds. Polymers may be further derivatized, crosslinked, grafted, branched, or end-capped. Non-limiting examples of polymers include copolymers, terpolymers, quaternary polymers, quaternary polymers, and homologues. The term "copolymer" refers to a polymer consisting substantially of two or more monomers of different types that are polymerized to obtain said copolymer.

[0055] As used herein, the term "prepolymer" refers to any polymer or oligomer preformed prior to the encapsulation process stage, and which may undergo some form of physical or chemical transformation, such as reaction (chain extension, branching, molecular rearrangement, crosslinking, ionic or other linkage or molecular association) or crystallization, during or after the encapsulation process.

[0056] Monomer reactants are defined as small molecule reactants that can react together to build polymer structures. They can be bifunctional or have higher functionality, or multifunctional or polyfunctional, or, if self-polymerizing, they can be monofunctional.

[0057] In many cases, the release rate and diffusion of the core material through the capsule wall can be controlled by altering the wall composition and / or the degree of cross-linking of the wall (shell) material. Furthermore, the degree of cross-linking of the wall material directly affects the strength and properties of the microcapsule wall. Additionally, encapsulation can significantly extend the lifespan of the material. Moreover, if the material is toxic and / or difficult to handle, encapsulation can reduce the threat of exposure and / or facilitate handling.

[0058] Fragrances, oils, and other lipophilic ingredients are widely used in personal and household care products, such as detergents, fabric softeners, shampoos, and shower gels, to enhance product performance and properties. Long-lasting fragrance release is a key performance parameter in many personal and household care products; however, many fragrances or oils are volatile, and their aroma effects dissipate quickly upon use. Encapsulating fragrances in a solid shell protects them and ensures a longer-lasting release. Among existing encapsulation systems, polymer microcapsules prepared via interfacial polymerization are widely used. These microcapsules can be achieved via oil-in-water (O / W) or water-in-oil (W / O) emulsions, where monomers typically react at the oil-water interface to form a polymer shell. Most commercial fragrance microcapsules are composed of poly(urea-formaldehyde), poly(melamine-formaldehyde), polyurethane, or polyurethane-urea shell materials, or polyacrylates. Exemplary references: The entire contents of US Patent 20080206291; WO 2013092375; US Patent 20130337023; Chem. Eng. J. 2009, 149, 463; and WO 2017123965A1 are incorporated herein by reference.

[0059] These specific systems, such as MF systems, or UF (urea-formaldehyde) or free radical crosslinked acrylates or crosslinked urea or carbamate systems, are chosen for their excellent thermal and mechanical properties. These systems are rigid or highly crosslinked to retain volatile components or components that tend to plasticize or dissolve other shell walls or leach through the shell walls of other systems, and are also chosen for their stability in a wide range of final product formulations. They typically use low-viscosity reactive monomers or reagents to ensure smooth interfacial or in-situ polymerization-encapsulation processes, resulting in rigid, highly insoluble, and highly crosslinked polymer systems. They are designed for durability, including long-term stability in a wide range of formulations across various pH ranges where the presence of salts, surfactants, solvents, or other additives that could damage some of the other polymer shell walls, and are also brittle, meaning they can break or fracture due to pressure or friction during use or when release is required. For example, the ability of the shell walls to "break" or crack during use, such as due to friction, is an attractive property of fragrance encapsulation for formulations or applications where fragrance release (instantaneous but lasting or repeatable over time) may occur. There is no requirement to protect such durable polymer shell materials, nor is their biodegradability expected in aquatic environments or other practical environments such as soil or compost. Typically, such highly cross-linked or rigid polymer particles or capsules are expected to persist in the environment, degrade very slowly, and / or are frequently produced using environmentally toxic or unfriendly materials such as formaldehyde or isocyanates. Other routes (such as coagulation) cannot produce robust capsules and / or may require the use of added undesirable solvents or undesirable animal-derived ingredients. A robust microcapsule is needed that can encapsulate and retain volatile substances or plasticized cargo until triggering release, and is biodegradable in its final environment, in many cases, an aquatic system such as rivers, oceans, or water treatment plants.

[0060] We have unexpectedly discovered that volatile or plasticizing hydrophobic or lipophilic components (such as fragrances, oils, and other lipophilic goods) can be encapsulated in a robust, storage-stable polymer shell that is biodegradable and can also exhibit similar or acceptable cargo retention, and can be contained (released) into some non-biodegradable, robust polymer shells, and in some cases, exhibit more prolonged cargo release, such as fragrances or oils or other lipophilic goods. Such polymer shells can be made using linear or branched polymers optionally having high Tg or crystalline domains, or using polymer systems that are lightly or heavily crosslinked with ester and / or β-amino ester and / or β-thioester moieties in their backbone and / or branches and / or crosslinks. Furthermore, in addition to successfully encapsulating and retaining potentially plasticized or solvated lipophilic goods, we have found that by selecting polymer shell precursors and polymer structures, such as linear or branched or crystalline or crosslinked polymer shell systems, such polymer shell materials can also meet important biodegradability criteria, particularly in surrounding aquatic environments such as seawater, river / surface water, effluent, and other water treatment process streams (such as activated sludge). Moreover, we have found that in some such combinations or systems, the biodegradable capsules of the present invention can also be stored "as is" or in various types of formulated final products having a certain pH range and also containing common formulation additives such as surfactants or solvents or salts. Therefore, this invention encompasses a series of microcapsule compositions based on polymer shells having the aforementioned esters and / or β-amino esters and / or β-thioesters, all of which can be designed to be biodegradable according to the standards described herein, and all of which encapsulate lipophilic cargoes and can be customized to meet combinations of properties that are difficult to achieve: biodegradability of the formulated product, storage stability, and triggering the release or containment of the cargo's properties, spanning a range of performance levels applicable to different formulated end products or applications and / or different encapsulated cargoes of those end product formulations. Furthermore, this invention also covers a series of methods for producing said microcapsules.

[0061] The capsules of the present invention can also be dried and stored in a dry state, and then redispersed in formulations. They can also be formulated directly into slurries, or after drying into dry or "anhydrous" formulations such as tablets or soap bars or printed solid products, as well as other solid forms for a variety of end applications, particularly but not limited to those for the personal and home care markets.

[0062] The biodegradation and non-durability of materials in the environment are influenced by a variety of factors. These include, for example, (a) the environment in which the material is used and / or after use, and many of these factors, such as temperature, humidity / presence of water, pH, microbial populations, nutrients, etc., and (b) the timescale for monitoring or predicting biodegradation. For the material of interest, material composition, structure, morphology, and physical dimensions and form are also important factors.

[0063] Evidence of biodegradability or non-persistence can be obtained by demonstrating a certain level of degradation over a period of time, and / or by demonstrating a rate of degradation that indicates the material will eventually degrade and is non-persistent after a certain time. There are many test standards or methods that specify certain tests and associated timescales. In use, some applications may require a specific level of biodegradation to be achieved at a specific timescale and in a specific environment to meet biodegradation indicators. Of course, for some applications, a specific level or percentage of biodegradation may be required, or even specified as evidence of faster biodegradation or a specific minimum level of biodegradation. Others may specify evidence of non-persistence. What kind of biodegradability and / or non-persistence indicators are needed or expected depends on the details of the end application, the expectations of the customer (usually the end-product manufacturer) or consumer (usually the end-user), and may vary depending on the end use and the end environment or regulatory directives or guidelines, from which there can be many variations. OECD, ISO, ASTM, EN, or other test standards are commonly used to determine biodegradability or compostability and can be used as indicators of non-persistence, or, in fact, conversely, as evidence of any possible persistence in the environment. However, these are not the only available methods; many publications report other methods or standards that have been peer-reviewed or are reasonable to those skilled in the art. Furthermore, different end-user sectors (products) and different regions of the world have different specifications or guidelines, therefore there is no single universal definition.

[0064] In the case of polymers, biodegradation typically begins with the breakdown of polymer chains or backbones into smaller components, a process that continues until they become small enough to be metabolized intracellularly by microorganisms such as bacteria, yeast, or fungi. Typically, the first step in the initial breakdown of polymers is via hydrolysis or oxidation of the polymer backbone chains to generate smaller molecules suitable for intracellular consumption. Hydrolysis is a particularly common first step and can be promoted, for example, by secreted extracellular enzymes (enzymatic hydrolysis; secreted by microorganisms in the final or test environment) and / or by specific environmental conditions (pH, temperature, etc.).

[0065] Many polymers are biodegradable and can persist in the environment for years or decades; for example, many plastics are frequently used in applications due to their long-term durability. Similarly, many particles or microplastics are known to persist in the environment in which they ultimately reside. This includes microcapsules of many existing technologies, such as those based on MF, UF, croscarmellose, or polyurethane, as well as croscarmellose polyacrylates. This has become a global environmental concern, leading various countries and organizations (such as ECHA) to potentially ban or restrict the use of persistent microplastics in certain products. In some respects, depending on the materials used and their properties, microcapsules can be considered a form of microplastic. As mentioned above, microcapsules are highly effective in protecting cargo (retained active ingredients or components) and / or controlling the release of cargo. Therefore, biodegradable microcapsules are being sought.

[0066] Biodegradable capsules are known, particularly in biomedical and pharmaceutical applications. Common polymers include polyesters, among others. Biodegradation in such applications occurs in the physiological environment of the human (or animal) body, typically at 37°C, and often with extreme pH values ​​and / or abundant enzymes or nutrients that particularly promote the breakdown of such polymers. Typically, the cargo is a solid or water-soluble active ingredient and / or does not contain volatile or reactive components. Routes for manufacturing such capsules also involve undesirable solvents (such as dichloromethane) and / or processes such as microfluidics, freeze-drying, or evaporation processes, or extrusion methods, which are technically and / or commercially impractical for encapsulating volatile fragrances and similar lipophilic cargoes, or for applications in the cosmetics, personal care, and household industries. Furthermore, biodegradability in this biomedical / pharmaceutical environment (which has higher temperatures, the presence of enzymes, and more corrosive conditions (for degradation)) does not indicate biodegradability in surrounding waterways or seawater, or is comparable to biodegradability in surrounding waterways or seawater, and does not reflect the needs of the personal care or household industries, as well as other industries (such as drilling / energy), where many products used will eventually enter aquatic environments such as rivers, oceans, surface water, water treatment plant / effluent (which is essentially water at ambient temperature (20°C or lower)), or enter soil or sediments.

[0067] It has been reported that some microcapsules or other ingredients used in the personal care and household industries today may be potentially considered persistent in the environment, and they may fall under the general definition of microplastics, which is therefore undesirable. At some point in the future, the use of all such products classified as microplastics in personal care, household, and other products may be restricted. ECHA has initiated a proposed process for this. Other bodies may develop similar or alternative guidelines or schemes. Therefore, there is a need to develop polymer capsules that are biodegradable in the environment where common personal care and household products may eventually enter. Demonstrating the reasonable biodegradability of an ingredient, assuming other factors are also favorable, may avoid such restrictions. In some cases, OECD and ISO test methods are typically prescribed for biodegradation testing. Other test standards are also used, and these may be relevant, including new standards to be developed or prescribed in the future. Therefore, there is a need to develop polymer capsules that are biodegradable in the environment where common personal care and household products, and many other products, may eventually enter, and that can be manufactured in a commercially reasonable manner for the industry (and therefore without the use of solvents, for example, requiring evaporation or high-temperature encapsulation processes).

[0068] In some OECD biodegradation tests for aqueous media, these tests are typically conducted on relatively short timescales such as 28 days. Under specific test conditions, achieving 60% degradation in some OECD tests may classify a material as readily biodegradable. This implies that such a material is rapidly biodegradable. In some OECD tests, achieving 20% ​​biodegradation may indicate that a material is classified as inherently biodegradable or Class I inherently biodegradable. This suggests that the material has biodegradable potential but requires a longer timescale than readily biodegradable materials. Although 28 days is the standard duration for some OECD tests, for inherent classifications, if biodegradation begins within 28 days and has not yet reached a plateau, the test time may be extended to 60 days or longer (e.g., see Annex 1 of the OECD document: OECD Guideline for Testing of Chemicals: part 1 Principles and strategies related to the testing of degradation of organic chemicals, https: / / www.oecd.org / chemicalsafety / testing / 34898616.pdf, particularly paragraphs 21 and 36).

[0069] Therefore, for the purposes of this invention, evidence or data or indications of biodegradability or non-persistence in aquatic environments or media (such as activated sludge, secondary effluent, river water, surface water, or seawater) are tested according to OECD testing standards, although it may take longer than 28 days for biodegradation to begin and before reaching a plateau. Typically, the biodegradation tests described herein are performed according to OECD or ISO testing protocols, such as those described in OECD 301, 302, 306, 310, or EN ISO 14852:2018, EN ISO 14851:2004, EN ISO 19679:2016, EN ISO 18830:2006, or EN ISO 17556:2012, or similar or other standards. If approximately 20% biodegradation is achieved within 28 days when using such tests, or if approximately 20% biodegradation is achieved over a longer period after biodegradation begins within 28 days and has not reached a plateau, this is provided as evidence of biodegradability or non-persistence. When tested according to this standard, if no apparent plateau is observed, such biodegradability is demonstrated within 28 or 40 days, or 45 or 60 days, or 90 days or 3 months, or 6 months, or 12 months or longer. Preferably, for the purposes of this document, 20% biodegradation will be achieved within 60 days in such a standard OECD water medium and will not show a plateau in the biodegradation versus time graph. Therefore, for the purposes of this test, biodegradability indications or data refer to the achievement of 20% biodegradability without a plateau in accordance with the OECD test methods and descriptions for inherent biodegradability or inherent primary biodegradability indications, including the achievement of 20% biodegradation within a permissible longer timescale. It should be noted that failure to achieve such a level does not indicate persistence—other tests can be applied to demonstrate non-persistence or biodegradability in water or other media. Furthermore, such OECD water tests are typically conducted under ambient conditions (20-25°C or lower) and it will be recognized that if biodegradability in aquatic media is demonstrated, biodegradability in other media (compost, soil, and sediment) is readily achievable. Additionally, readily biodegradable properties are also covered if demonstrated. Moreover, OECD methods are not the only relevant testing methods, although they have been used in this document for testing data. Other standards may be accepted by others and used in certain regions or applications. Other standard testing methods or reasonable variations may be used, and other data may be accepted by industry regulatory bodies or experts if reasonable or logical reasons are presented and / or if other evidence of non-persistence can be presented and is acceptable to those skilled in the art. For example, a decrease in molecular weight or weight loss or other measurements may be used as an indication of biodegradation or non-persistence, particularly for materials that degrade more slowly. Degradation half-life determinations are also used.Depending on the context, all of these may be relevant. This literature reports biodegradation data using OECD testing methods, but it is generally accepted that other tests or standards of this kind can also be used to demonstrate biodegradation or non-persistence. In particular, for many sample or material types that are insoluble in water, dispersions, or membranes, other methods are used to obtain reliable sample forms for biodegradation testing. It is recognized that current testing methods (OECD or others) for the biodegradation of polymers in aqueous media are not necessarily representative because they were not initially designed or intended for testing such materials, especially water-insoluble polymers, and refined, improved, or modified, potentially more relevant testing methods may be developed from time to time (see, for example, Kowalczyk, A. et al. (2015) Refinement of biodegradation tests methodologies and the proposed utility of new microbial ecology techniques. Ecotoxicology and Environmental Safety, 111, 9-22. https: / / doi.org / 10.1016 / J.ECOENV.2014.09.021 and: Timothy J. Martin et al. (2017) Environmentally Relevant Influence Concentrations Improve the Reliability of Persistent Assessments in Biodegradation Screening Tests.Environ.Sci.Technol.2017,51,3065-3073,DOI:10.1021 / acs.est.6b05717). It is expected that if a material exhibits signs of biodegradability or potential non-persistence in the OECD or ISO tests reported in this literature, it will likely be biodegradable or non-persistent in future test specifications, potentially better suited to the polymer and current or future environments. Furthermore, if a polymer exhibits even low levels of persistent biodegradability when tested in seawater (ocean), surface / river water, or activated sludge, such a material is likely to exhibit a higher rate or extent of biodegradability in more active media (such as soil or compost), or in other media where enzymes or microorganisms are present at higher concentrations or diversity. If a material exhibits biodegradability in typical aquatic media tests, it is reasonable to assume, and generally understood, that the material is also expected to be compostable according to various compostability standards.Furthermore, similarly, if a material is biodegradable in an aquatic medium, it is reasonable to assume it is biodegradable in soil or similar media. However, the opposite cannot be stated. Therefore, if a material is proven to be compostable, it should be understood that this does not mean it will degrade in waterways or other surrounding aquatic media. Polylactic acid (PLA) is a well-known example of a compostable polymer (polyester) but it does not biodegrade in aquatic media or soil. Therefore, according to typical standard testing methods, the tests in this invention are based on an aquatic medium and are grounded in the assumption that if a material exhibits biodegradability in the surrounding aquatic medium, it will also be compostable and biodegradable in soil.

[0070] Therefore, in summary, those skilled in the art will understand that for biodegradability testing, all conducted at approximately 20-25°C, as described in the aforementioned OECD tests, the biodegradability tests in aqueous media (such as surface water, secondary effluent, or activated sludge) are relatively mild, and as biodegradability tests, they are certainly less corrosive than those conducted, for example, in industrial composting facilities and via test methods or standards developed for compostability testing (such as EN13243, ASTM D-6400, or ASTM D-6868). In such compostability tests, much higher temperatures are commonly used, for example, approximately 58-60°C. It is understood that many polymers, including polyesters (such as polylactic acid), which exhibit biodegradability in industrial composting tests, do not show biodegradability in aqueous media tests (see, for example: Bagheri, AR, Laforsch, C., Greiner, A., Agarwal, S.: Global Challenges 2017, 1700048; DOI: 10.1002 / gch2.201700048). However, polyesters, or indeed other polymers, that do show signs of biodegradability in such aqueous OECD tests can be confidently expected to be compostable and pass compostability tests.

[0071] For example, a highly useful application of microcapsules is for prolonging the encapsulation of fragrances or other ingredients already encapsulated within a polymer shell. Typically, technologies or materials used for encapsulating fragrances or similar molecules (goods) include melamine-formaldehyde-urea / polyurethane technology or acrylate technology. Most utilize the cross-linked networks of these polymers to improve the stability and durability of the formulations used (e.g., laundry / detergent products, household cleaning products, hair care products, skin care products, etc.).

[0072] Therefore, the manufacture of microcapsules capable of containing hydrophobic or lipophilic groups, which may also optionally be volatile and / or plasticizing, requires some alternative methods known in the prior art to manufacture microcapsules suitable for encapsulating lipophilic or hydrophobic goods, but also biodegradable, especially in aquatic environments (such as seawater, river water, surface water or water treatment effluent, process or activated sludge).

[0073] One object of the present invention is to meet these criteria and thus ensure the ability to produce microcapsules with a shell material that is biodegradable or non-durable, particularly in aqueous media / channels, and that can retain hydrophobic or lipophilic cargoes, or volatile, plasticizing, or oil-soluble cargoes (such as fragrances, essential oils, or any other oils), and be stably stored in product form prior to use. Fragrances are of particular interest because they are used in many end products, but they typically contain some volatile or low-boiling-point components (which would evaporate rapidly if not contained in a certain way), and / or components that can plasticize many polymers.

[0074] To the extent that there are existing patents and publications concerning the microencapsulation of lipophilic active ingredients, numerous examples exist of microencapsulation of both hydrophilic and lipophilic components for pharmaceutical or biomedical applications, describing biodegradable shells for controlled release. Biodegradation in such physiological environments does not necessarily imply biodegradation in waterways or similar environments. Physiological environments are typically warm (37°C), contain mixtures of specific degrading enzymes not present in, for example, waterways, and / or have localized pH extremes, and / or also contain salts and many other chemical entities. Generally, they are relatively corrosive media for degradation purposes for controlled release. Furthermore, shell wall materials (many of which are polyesters) and / or processes typically used for drug or pharmaceutical active ingredient delivery are generally unsuitable for volatile or plasticized cargoes. Many processes use extrusion (high temperatures) or solvents (requiring evaporation to very low residue limits), and when these processes do use undesirable components or reactants in the shell wall (e.g., isocyanates in polyurethane shells), they will require extensive cleaning or post-treatment to ensure removal of trace amounts of such components. Many pharmaceutical-based encapsulants use polylactide, polyglycolic acid, or poly(glycolic acid-co-lactide (PLGA) polyester) as capsule shells, for example, using dichloromethane as a promoting solvent for the encapsulant, and subsequently must be removed by evaporation. All of these aspects are unsuitable for volatile or plasticized goods, and / or prohibitively expensive for applications outside of pharmaceuticals in their post-processing or other stages. The development of biodegradable capsule shells, aside from those for pharmaceutical or biomedical applications, in which case, as just mentioned, the final environmental conditions (pH, temperature, and / or the presence of specific enzymes, etc.) are significantly different from those in waterways and soil, and the manufacturing processes are less suitable for those in smaller individual or household markets, all of which have disadvantages hindering their widespread practical application. The present invention overcomes these disadvantages while also meeting the aforementioned criteria.

[0075] In existing technologies claiming protection for polyesters used for encapsulation, some are used for water-soluble active ingredients and are therefore unsuitable for hydrophobic or lipophilic materials; few exhibit or claim biodegradability, none exhibit or claim biodegradability in ambient water or in relevant OECD tests; many use organic solvents to ensure encapsulation, which presents problems when removing volatile cargoes and when used with volatile cargoes; some prepare the polyester itself in situ via interfacial polymerization in the presence of cargoes, where one reactive or catalytic component is in the aqueous phase and another in the oil phase, and therefore they must use undesirable acyl chlorides to maintain low reaction temperatures and thus maintain emulsion stability and relatively short reaction times (such as the higher temperatures required for diacid-diol condensation reactions, which typically destabilize the emulsion and lead to encapsulation failure and loss of fragrance or similar cargo components), and / or require the use of undesirable solvents and their evaporation. None of these claims or indications support a successful combination of such biodegradable properties with fragrances or similar volatile lipophilic goods that have the property of significantly containing or releasing the goods upon triggering (e.g., friction or application of pressure). Furthermore, when formulated with fragrances or oils or other plasticized goods internally, little (if any) storage stability is exhibited, or when used in household or personal care applications that may have extreme pH values ​​or surfactants or salts or solvents or other additives that may plasticize or erode the shell walls, little (if any) storage stability is exhibited in the final product formulation.

[0076] In one embodiment, this application provides a microcapsule comprising: (i) a lipophilic core; and (ii) a polymeric microcapsule shell; wherein the polymeric microcapsule shell comprises a polymer or crosslinked polymer, said polymer or crosslinked polymer being an aliphatic polyester or poly-β-amino-ester or poly-β-thioester, or copolymers or terpolymers thereof, or mixtures thereof; wherein the microcapsule is storage stable and its polymeric shell is biodegradable. According to OECD testing methods, the polyester-based capsules of the present invention exhibit successful microencapsulation, subsequently triggering the release of fragrances or other lipophilic goods, and relevant evidence of biodegradability or potential non-persistence in aqueous media, and are manufactured via a convenient process at low to moderate temperatures suitable for encapsulating volatile components, without the need for subsequent removal of volatile solvents, or the use of undesirable isocyanates or acyl chlorides, or the use of high temperatures during the encapsulation stage.

[0077] Poly-β-amino ester and poly-β-thioester homopolymer complexes, granules, and capsules are also described. The polymers are typically prepared via Michael addition or conjugated addition, an addition reaction in which a bifunctional or multifunctional donor (e.g., an amine (primary or secondary amine, Aza-Michael) or a thiol (Thio-Michael)) reacts with a bifunctional or multifunctional acceptor (e.g., an activated (electron-deficient) conjugated double bond, as is well known in the art in acrylates or related molecules). Solvent-based methods, such as using water as a solvent, are commonly used to prepare hydrogel-based encapsulations from these precursors. Although less frequently, other solvent-mediated processes or classical interfacial polymerization (oil-in-water, where the donor is one phase and the acceptor and / or catalyst is in another, thus requiring water-soluble reactants) have also been used to manufacture capsules from these polymers and precursor Michael addition agents. These typical methods have drawbacks when attempting to encapsulate polar or volatile or plasticized goods in a robust, highly crosslinked, or rigid shell.

[0078] When a water-soluble donor reacts with a water-soluble acceptor in water, a hydrogel matrix capsule is typically produced. These are suitable, for example, for the controlled release of drugs over time. Hydrogel matrix capsules generally do not possess the same holding power or stability as core-shell capsules and, post-manufacturing, are less suitable for encapsulating ingredients or active substances (e.g., fragrances) in situations where a more immediate release of the cargo is desired. Furthermore, they are not suitable for storage in water-based formulations that require prolonged retention before the release of their cargo. When solvent-mediated processes are used to encapsulate such agents, solvent removal is typically required (usually involving evaporation and / or other complex double emulsion or other processes), and as mentioned above, these methods are less suitable for volatile cargoes or commercially viable personal or home care applications. Additionally, many existing technologies describe poly-β-amino esters for biomedical / pharmaceutical environments and are suitable for use in these media due to their very rapid degradation—they exhibit good biodegradability—but are not suitable for storage in aqueous formulations, such as those used in personal or home care applications (until required).

[0079] Similar comments apply to polyβ-thioesters: hydrogels can be prepared but with similar drawbacks as just described. Likewise, several publications relate to pharmaceutical or biomedical applications. One instance outside this field does report a classic interfacial polymerization for the synthesis of fragrance capsules. (See: Liao et al., Fragrance-containing microcapsules based on interfacial thiol-ene polymerization. J. Appl. Polym. Sci. 2016, doi:10.1002 / App.43905). This publication does not suggest or measure any biodegradability properties, nor does it design capsules with any biodegradable reactivity. Furthermore, in such classic interfacial oil-in-water polymerization (and encapsulation), typically an oil-soluble acceptor (e.g., if the acceptor is a bifunctional acrylate) or donor reacts with a water-soluble donor (e.g., if the donor is a bifunctional amine or thiol) or acceptor. Interfacial polymerization of such systems typically involves placing the cargo and a monomer (here, the acceptor) in an oil phase and emulsifying with a water-surfactant mixture to prepare a pre-emulsion. Subsequently, a second monomer, which must be water-soluble (here, a thiol donor), is mixed with the pre-formed emulsion, and the interfacial polymerization reaction continues, forming a shell around the cargo at the interface. This interfacial polymerization is disadvantageous for this type of packaging of certain goods for several reasons, including those that are more polar, plasticizing, or volatile molecules, and many natural or essential oils or fragrances, or other hydrophobic or lipophilic goods; firstly, an excess of donor (e.g., amines or thiols) is often required to produce such interfacial polymerization, and a more rigorous washing or cleaning process is required at the end of the reaction due to the presence of residual (unreacted) monomers. This is very inconvenient, wasteful, and expensive for commercial processes, as very low residual amounts of such reactants are typically required for personal or home care products.

[0080] Furthermore, in cases where excessive thiols are used, as described herein, unpleasant odor problems may arise due to residual unreacted thiols—as in the case of this reference, where a 50% molar excess of such water-soluble thiols (1.5SH vs. 1 acrylate bond) is considered necessary, thus resulting in high levels of residual thiols and associated odors. Secondly, donors such as water-soluble amines or water-soluble dithiols are relatively hydrophilic, therefore the resulting polymers are more prone to swelling or softening in water or polar solvents, and thus may be more susceptible to leakage when stored in aqueous media (e.g., immediately after preparation) or when formulated in aqueous media (which is common, for example, in many applications in laundry, or home care, or personal care). This can negatively impact cargo retention (e.g., fragrances or oils or other hydrophobic cargoes) and / or storage stability over a wide pH retention range, especially where gradual release over time is not sought. Third, the use of polar, water-soluble / hydrophilic polyamines and similar hydrophilic donors makes such capsules hydrolyzable, leading to premature degradation in aqueous media (e.g., immediately after manufacture and / or during formulation)—and consequently, poor storage stability in aqueous media immediately after manufacture and / or at pH values ​​far from neutral (such as acidic pH 3). While this may be advantageous for biodegradability in some cases, as mentioned above, it is a major drawback when the capsules are stored long-term as aqueous dispersions or slurries (in their commonly prepared forms) or as formulated products (e.g., liquid detergents, fabric conditioners) and are aqueous, potentially with extreme pH values. Fourth, if the capsule shell requires a very high cross-linking density, such as when both the acceptor and donor are highly multifunctional (e.g., each reactant is trifunctional or higher), as in some applications described herein, where a particularly robust capsule is needed, the classical interfacial polymerization route can be very limited. This is because when the two highly functional donor and acceptor molecules co-react and polymerize at the interface, they will rapidly form a highly cross-linked shell structure in the reaction zone relatively early. This prevents other donors (e.g., amines or thiols) from migrating or diffusing from the aqueous phase into the polymerization zone, thus limiting the conversion of donors (e.g., amines or thiols) and / or acceptors (e.g., acrylates) and limiting the acquisition of shells with even higher cross-linking structures, which are necessary for more robust capsules (remaining stable until breakage and / or storage stability). This latter case is one of the reasons why an excess of donors (e.g., amines or thiols) is often required in such classical interfacial polymerization, as mentioned above, it has such significant drawbacks. In fact, this is likely why only bifunctional thiols can be used, as cited in the publications—and where they must be used in 50% excess compared to a 1:1 stoichiometry of equal groups. This diffusion problem would be even greater when using thiols with higher functionality than dithiols.

[0081] For prior art involving microcapsules derived from poly-β-amino esters or poly-β-thioesters, all of these prior art describe classic oil-in-water polymerization to form microcapsules. These prior art follow classic interfacial polymerization processes, which are limited in achieving the high crosslinking densities required for the most demanding end-product applications and require the use of one of the reactants at an excess level. None of the prior art for manufacturing capsules via this method reports multifunctionality (above bifunctionality) of the donor and acceptor reactants. Furthermore, in such prior art, one of the monomeric reactants needs to be water-soluble, which can limit the design of the final composition of the wall polymer structure, especially for demanding home or personal care applications. In addition, none of the prior art regarding such amino ester or thioester microcapsules claims or exhibits a combination of properties such as storage stability, associated biodegradability, and successful encapsulation of cargo, and a combination of imparting significant containment or release properties to the cargo upon triggering after storage or binding to a formulation (e.g., when rubbed or under pressure). Furthermore, none of them describe the combination of amino esters or thioesters in the same microcapsule shell material, nor do they describe the in-situ oil-in-water polymerization process used for its production (where all reactants are in the oil phase) and its associated advantages, such as achieving the desired balance between the selected reactants and the required crosslinking density for the most demanding applications.

[0082] The poly-β-amino ester, or poly-β-thioester, or hybrid poly-β-amino ester-co-β-thioester, or polyester / β-amino ester, or polyester / poly-β-thioester hybrid capsules of the present invention exhibit successful encapsulation and subsequent triggered fragrance release, and demonstrate relevant evidence of biodegradability or non-persistence over time in aqueous media according to OECD testing methods. They are manufactured via a simple in-situ process, requiring no significant excess of reactants at low to moderate temperatures suitable for encapsulating volatile components in oil-in-water processes, without the need for subsequent removal of volatile solvents, and without the use of undesirable isocyanates or acyl chlorides, and without the need for high temperatures during the encapsulation stage. Furthermore, they exhibit a combination of encapsulated fragrance, biodegradability, and storage stability across a variety of formulations and pH ranges.

[0083] The present invention relates to biodegradable microcapsules, particularly microcapsules that: (a) can encapsulate and retain cargo, which can then be released by triggered release and / or gradual release, especially when such cargo is or contains a lipophilic or hydrophobic core material (such as flavorings, butter or essential oils or other oil or oil-soluble cargo); (b) whose shell material exhibits signs of biodegradation or non-persistence in the environment, particularly in aquatic environments (waterways, rivers, surface water, seawater, sludge, treated water, etc.) and / or soil or compost-based environments; and (c) are stable when freshly made or stored in one or more final product formulations.

[0084] The present invention also describes routes for manufacturing capsules (microcapsules) of micrometer (and larger) size, which can be used to encapsulate sensitive or plasticizing or volatile lipophilic or other hydrophobic ingredients or active substances, such as oils, fragrances, butters, or oil-soluble ingredients. The biodegradable microcapsule polymer shell compositions are effective for a variety of applications, including but not limited to personal care products, home care products, etc.

[0085] Our method unexpectedly reveals the ability to prepare polymeric shell capsules for encapsulating fragrances, oils, and other goods that exhibit lipophilic tendencies, compatibility, or behavior, and are stable in aqueous media (such as “freshly made”) or in aqueous formulations with various pH values ​​and optionally containing surfactants or other additives, but are biodegradable in common, ambient, aquatic environments after use. Insoluble materials can be encapsulated in lipophilic carriers or diluents by dissolution or partial dissolution or via dispersion or emulsification.

[0086] While polyester is one polymer base that can be used, it is not the only one, and not all polyesters or copolyesters are suitable. Those with a degree of resistance to degradation or that degrade too slowly to be considered non-durable are unsuitable because it is ultimately impossible to predict or expect them to degrade in the environment. A common example of a polyester that is not considered biodegradable by the criteria herein, but is considered durable in the environment if unmodified, is polyethylene terephthalate (PET), which is known to be a more durable polyester and is therefore used in many applications. Other polyesters based on high terephthalate or other high aromatic content are also non-biodegradable, and this is expected to be the case for those polyesters prepared from terephthaloyl chloride used in the aforementioned prior art patents. Generally, polyesters with high terephthaloyl groups are non-biodegradable in aquatic environments or other common end environments. This also applies to other polymers with a significant amount of aromatic chains in the polymer backbone.

[0087] Furthermore, polyesters or other types of polymers that are soft solids or viscous liquids after capsule formation, or that are easily plasticized or solubilized (after capsule formation), may be impractical for directly encapsulating certain lipophilic or volatile goods, although in some cases they may be suitable for other goods that do not plasticize or solubilize the shell walls too much. Additionally, highly cross-linked polyesters, linked by a high content of carbon-carbon crosslinks (bonds) or by non-biodegradable or non-hydrolyzable segments or chains (e.g., polystyrene chains in known cross-linked unsaturated polyesters), are also non-biodegradable. We have found that certain polyester or copolyester structures can achieve a unique balance of hydrophobicity or lipophilicity sufficient to promote some compatibility with lipophilic goods while ensuring degradation to a specific level within a specified time and / or at a rate indicating eventual biodegradation and non-persistence in the environment (including aquatic environments).

[0088] A key aspect of one embodiment of the invention and its variations can be described as follows: synthesizing a prepolymer that is biodegradable in a selected medium (such as seawater, river water, activated sludge, etc., or soil or compost), the synthesis optionally, but not necessarily, having specific reactive groups within or at the chain ends. The term prepolymer is used herein to describe any polymer or oligomer pre-formed prior to the encapsulation process stage, during which the polymer or oligomer is converted to form a microcapsule shell, and which is biodegradable or hydrolyzable, and initially compatible with heated cargo (or cargo dilution mixtures) as described below. The backbone of the prepolymer will have a certain level or arrangement of heteroatoms, such as O, or N, or S, or P, to facilitate hydrolysis or biodegradation at a later stage (typically after use). Preferred prepolymers contain ester bonds and / or β-amino ester bonds and / or β-thioester bonds, optionally having amide bonds and / or ether bonds and / or thioether bonds and / or carbonate bonds and / or urethane bonds, but must ensure that their structure and composition are biodegradable according to the criteria described herein.

[0089] In another embodiment, the present invention provides a microcapsule shell comprising a branched or crosslinked polymer derived from an aliphatic polyester prepolymer selected from aliphatic polyesters containing at least one reactive unsaturated functional group present at the chain ends or distributed along the chain. The aliphatic polyester comprises a crystalline structure and is derived from at least one C2-C... 20 Aliphatic chains or branched C2-C 20 A diacid, diester, diacyl chloride, or anhydride with an aliphatic chain or a combination thereof, and at least one containing C2-C 20 Aliphatic chains or branched C2-C 20 Diols of aliphatic chains or combinations thereof.

[0090] Therefore, aliphatic polyesters are derived from at least one diacid or polyfunctional acid preferably selected from the following: succinic acid, malic acid, malonic acid, succinic acid, adipic acid, octanoic acid, decanedioic acid, sebacic acid, dodecanoic acid, octenylsuccinic acid, itaconic acid, maleic acid, and dodecenylsuccinic acid; or at least one anhydride selected from the following: succinic anhydride, dodecenylsuccinic anhydride, and octenylsuccinic anhydride; and at least one glycol selected from the following: ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, decanediol, cyclohexanediol, isosorbide, neopentyl glycol, ethylhexanediol, and dodecanediol.

[0091] The prepolymer can be melted or dissolved (and heated if necessary) into the cargo (optionally with the addition of a diluent or carrier), and therefore must also be designed to be compatible with the cargo or a mixture of cargo and diluent upon heating. Optionally, it can also be incorporated into a co-reacting agent (which can react with specific reactive groups within or at the chain ends and / or facilitate dissolution), or a crosslinking initiator (e.g., a free radical), and / or other catalysts, or accelerators, and / or additives, which may, for example, facilitate crystallization or be able to form complexes, salts, or other forms of interaction with the prepolymer to transform the prepolymer during the capsule shell formation process. Alternatively, it can also be incorporated into an inert, biodegradable polymer additive, thereby forming a polymer shell wall from a blend of polymers.

[0092] Prepolymers may contain reactive groups, such as unsaturated groups, at the chain ends or distributed along the chain, which can be used for the transformation of the prepolymer during shell wall formation. Therefore, the reactive unsaturated functional groups are selected from acrylates, methacrylates, itaconic acid esters, citrate esters, maleic acid esters, fumarate esters, crotonic acid esters, and combinations thereof.

[0093] The polymer-cargo mixture (oil phase, with optional diluent) is mixed with an aqueous phase, which may be water alone or water with added stabilizers or other additives. Optionally, a co-reacting agent (which can react with specific reactive groups within or at the ends of the chain) or a crosslinking initiator (free radical) and / or additives may also be incorporated, such as those that may facilitate crystallization or be able to form complexes, salts, or other forms of interaction with the prepolymer. The mixture is homogenized or vigorously stirred while being warmed or heated to form an emulsion.

[0094] Capsules may be formed during stirring or homogenization and / or when cooled to ambient temperature or lower. For example, an insoluble polymer (insoluble in cargo and insoluble in water) shell wall may be formed by crystallization or solidification or precipitation of the polymer or prepolymer upon cooling, and / or by crosslinking or chain extension or branching reactions between prepolymer molecules and / or between the prepolymer and added co-reacting agents, and / or by molecular rearrangement, and / or by the formation of complex or ionic salt bonds, or by interactions that link prepolymer molecules together and / or link prepolymer molecules to added agents.

[0095] Variations in the order of addition are also included. For example, a prepolymer with a stabilizer (polymer such as polyvinylpyrrolidone, PVP) and / or granules (such as silica) can be added, followed by the addition of a water-polyvinyl alcohol (Poval)-fragrance mixture and homogenization. This can be done at ambient temperature or under heating.

[0096] Mixtures of stabilizers, as well as mixtures of stabilizers with added polymers, can be used (and combined at different points) to supplement and / or help control viscosity or stability. For example, stabilizers used alone or as part of a mixture may include polyvinyl alcohol, polyvinylpyrrolidone, hydroxyethyl cellulose, hydroxypropyl cellulose and other cellulose derivatives, guar gum, guar gum derivatives including cationic guar gum, gums including xanthan gum, starch and starch derivatives, and / or any known emulsifiers or dispersants, and may include particulates such as silica. Pickering emulsion methods may also be used. Defoamers are also used, which may include liquid hydrocarbons, oils, hydrophobic silica, fatty acids, alkoxylated compounds, polyethers, polyalkylene glycols, and nonionic emulsifiers.

[0097] This process overview and variations thereof can be used to produce microcapsules having a shell wall that is biodegradable in a selected medium and can also encapsulate and retain lipophilic cargo.

[0098] Microcapsules, as described above, are formed through a dissolution process of a biodegradable prepolymer or pre-oligomer, wherein a polymer shell is formed around the cargo, the prepolymer / pre-oligomer containing ester bonds and / or β-amino ester and / or β-thioester bonds, optionally having amide and / or ether and / or thioether and / or carbonate and / or carbamate bonds, in the case of a lipophilic cargo, optionally with the addition of a diluent or other reagent and / or heating followed by emulsification with water, and achieving a conversion of the prepolymer or pre-oligomer to make it insoluble in the lipophilic cargo, such conversion being achieved via reaction, molecular rearrangement or interaction and / or phase or solubility change of the prepolymer or pre-oligomer within or from a mixture thereof with a fragrance and diluent (if present), and wherein such converted polymer (capsule shell wall) encapsulates the cargo and remains biodegradable or non-durable in the environment. The diluent or solvent is selected from hydrocarbon oils, alkanes, ester oils, fatty acid esters, aliphatic esters, and hydrocarbon carbonate esters. Therefore, microcapsules with biodegradable shell walls are prepared as described above, wherein such polymer shells are formed around the cargo.

[0099] In some cases, the product may be granules with encapsulated, absorbed, or adsorbed cargo rather than fully formed capsules, or it may be a capsule that functions in both ways. The encapsulated or absorbed cargo is still retained, but typically for a shorter period compared to cargo completely encapsulated within the shell. In some cases, it is also possible to form a combination of encapsulated, absorbed, or adsorbed cargo with encapsulated cargo. Furthermore, capsules or granules may form a film during drying, casting, or other processing, which also contains and retains the cargo for a certain period of time, all of which remain biodegradable.

[0100] In one embodiment, microcapsules containing encapsulated goods formed in a slurry (typically an initial reaction product mixture) can be dried as capsules and then, if desired, redispersed in water or an aqueous medium or formulation, and retained as biodegradable capsules.

[0101] In some embodiments, this application provides a prepolymer subsequently used in an in-situ oil-in-water microencapsulation process. Various reaction schemes for synthesizing the biodegradable prepolymer or polymer composition used are shown, including but not limited to the following schemes-I to-V:

[0102]

[0103] Scheme I: Exemplary synthesis of aliphatic polyester prepolymers (with / without reactive (unsaturated) end groups)

[0104]

[0105] Scheme II: Exemplary structure of aliphatic polyester prepolymer - having intrachain reactive unsaturated groups (e.g., via itaconic acid inclusions).

[0106]

[0107] Scheme III: Other Examples of Aliphatic Polyester Prepolymers

[0108]

[0109] Scheme IV: Other Examples of Aliphatic Polyester Prepolymers

[0110]

[0111] Scheme-V: (a) an exemplary synthesis of a PLGA copolymer coupled with an oil-solubilized (DSA-EG) oligomer, and (b) a methacrylate-terminated PLGA polymer / prepolymer.

[0112] In other embodiments, the polymer shell is constructed from an in-situ oil-in-water reaction of monomeric reactants. Examples are shown in schemes VI-IX below.

[0113]

[0114] Scheme VI: An example of in-situ polymerization of diacid and diol monomer reactants in microencapsulation of polycondensation (esterification) fine emulsions.

[0115]

[0116] Option VII: Preparation of poly-β-thioester microcapsules via in-situ oil-in-water polymerization and encapsulation

[0117]

[0118] Scheme VIII: Michael addition polymerization—microencapsulation with bifunctional or polyfunctional thiols and / or amine donors and Michael acceptors (e.g., bifunctional or polyfunctional acrylates).

[0119] Step 1

[0120]

[0121] Scheme IX: An exemplary scheme in which an amine donor is pre-reacted to prepare a β-amino ester prepolymer, followed by a thiol addition reaction to generate microcapsules having both β-amino ester and β-thioester moieties.

[0122] Some existing technologies that use pre-formulated polymers as encapsulation materials for encapsulating ingredients (typically non-volatile and / or thermally stable, often pharmaceutical ingredients) include some biodegradable polymers (typically biodegradable in bodily fluids / biomedical environments). These technologies typically employ melt extrusion (which requires exposure to relatively high temperatures and is therefore unsuitable for fragrances containing volatile components when using polymers (larger molecules) as raw materials) or solvent-based processes (which require subsequent solvent evaporation and are therefore unsuitable for fragrances containing volatile components).

[0123] Therefore, we have unexpectedly discovered that certain pre-formulated polyester or copolyester polymers can be used in subsequent (continuous one-pot or separate processes) emulsion or dispersion encapsulation processes without removing solvents or heating to high temperatures (above 100°C), and thus can be converted into capsule form via in-situ oil-in-water emulsification processes that can encapsulate volatile, hydrophobic, lipophilic, or oil-soluble components, and can also be designed to biodegrade over time in water or other environments according to the standards described herein, while retaining or containing or encapsulating fragrances or oils or related oil-soluble or oil-solubilized or other lipophilic goods.

[0124] In another embodiment, this application provides a pre-formed polylactide-co-glycolic acid (PLGA) polymer, copolymer, or terpolymer, which can be used in oil-in-water emulsion or dispersion encapsulation processes to prepare a biodegradable shell according to the standards described herein, without the use of undesirable volatile solvents that need to be subsequently removed and / or without the need for high-temperature extrusion or related processes, by using an added mild (non-volatile but acceptable for some end applications) diluent as a carrier for fragrances or other lipophilic or hydrophobic or oil-soluble or oil-solubilized goods, while retaining or containing such goods.

[0125] In one embodiment, the pre-formulated aliphatic polyester is a polymer derived from at least one lactide and at least one glycolide. The aliphatic polyester may be coupled with an attached oil-soluble oligomer or polyester chain. The oil-soluble oligomer or polyester chain contains C2-C... 20 Aliphatic chains or branched C2-C 20 Polyesters with alkyl side chains of aliphatic chains or combinations thereof, or oligocaprolactones or polycaprolactones.

[0126] In another embodiment, the aliphatic polyester is a polymer derived from the ring-opening polymerization of lactide or glycolide or a combination of both, coupled with an oil-solubilized or solvent-solubilized low-polyester or polyester chain used as a co-initiator, or linked by copolymerization or reactive coupling.

[0127] The retention time of fragrances or other goods in such capsules after application to fabrics or surfaces can vary. While there are exceptions, shorter times are generally achieved with linear polymers (i.e., typically without crosslinking after capping). In some instances, a more robust shell is formed after the encapsulation stage, resulting in a more persistent aroma effect, either through inherent chain rigidity / crystallinity or through chain extension to establish molecular weight during the encapsulation stage. Crosslinking generally results in a more robust shell and longer retention. Similar effects can also be observed through ion-salt-based interactions within or between capsule shell components, and / or the formation of crystalline domains on the cooled capsule once formed. In such cases, biodegradation times are typically longer, although longer periods can show signs of non-persistence (e.g., in some cases, ongoing biodegradation is observed, reaching levels >20% after a period).

[0128] Examples of other goods that can be packaged in any of the embodiments, besides fragrances, perfumes, essential oils or natural oils, include oil (ester or hydrocarbon) solubilized ingredients, liquids or low-melting-point solids, which are lipophilic esters, chlorinated solvents, hydrocarbons, insect repellents, pigments, colorants, dyes, vitamins, antioxidants, lipophilic natural extracts or other oily or oil (ester or hydrocarbon) soluble active substances.

[0129] Various other routes can also be used to prepare the capsules (microcapsules) of the present invention, which can contain, retain, or encapsulate hydrophobic or lipophilic goods, such as fragrances or oils, and can also be biodegradable in water or other environments. As mentioned above, the prior art also describes the use of small molecule monomers or precursors to react in situ in emulsion or dispersion processes to form polymers or cross-linked polymer networks in situ from small molecule (monomers) such as acrylate monomers, or melamine-formaldehyde (MF), or isocyanates with diols or diamines (for polyurethanes or polyureas), for encapsulating oils or fragrances with good retention. Prepolymers are not necessarily manufactured or required here. We have discovered that biodegradable polymer shells for microcapsules used to encapsulate lipophilic goods (such as essential oils) (the walls of which contain ester and / or β-amino-ester and / or β-thioester bonds, optionally with amide and / or ether and / or thioether and / or carbonate and / or carbamate bonds) can also be manufactured via a small molecule precursor (monomer) route, without necessarily requiring the manufacture of prepolymers, although prepolymers may also be present in such methods.

[0130] In such methods, we have unexpectedly discovered that certain polyester shells, which can be designed to be biodegradable according to the criteria described herein and can contain, retain, or encapsulate fragrances or other lipophilic or oil-soluble goods, or polyester compositions that can be used as microcapsule shells, can be prepared from monomeric precursors such as diols and diacids in the presence of fragrances and other lipophilic goods (oil phase) via in-situ polymerization-encapsulation emulsion (oil-in-water) polycondensation process, without the use of acyl chlorides or isocyanates and / or without long-duration reactions, preferably with all monomeric reactants in the oil phase from the outset.

[0131] In another embodiment, we have also unexpectedly discovered that a certain highly branched or cross-linked polymer shell comprising β-amino esters and / or β-thioesters and containing, retaining or encapsulating lipophilic or oil-soluble cargoes of fragrances or other substances can be designed to be biodegradable according to the criteria described herein, and can also be manufactured by an in-situ polymerization-encapsulation emulsion (oil-in-water) process, preferably with all monomeric reactants in the oil phase from the outset, without the need for water-soluble precursors and / or without the need for large excesses of reactive monomers and / or without the need for long-term reactions at high temperatures.

[0132] In some embodiments, the polymer or crosslinked polymer is a poly-β-amino-ester or a poly-β-thio-ester or any combination thereof, derived from a Michael or conjugate addition reaction of the donor and acceptor, wherein the donor or acceptor has at least two or at least three reactive functional groups.

[0133] In one non-limiting embodiment, the polymer microcapsule shell is derived from a donor-acceptor combination selected from: (i) trifunctional, tetrafunctional, pentafunctional, or hexafunctional thiols; and (ii) trifunctional, tetrafunctional, pentafunctional, or hexafunctional acrylates.

[0134] Another embodiment discloses that the crosslinked polymer is a poly-β-amino-ester or a poly-β-thio-ester or any combination thereof, and is derived from (i) at least one multifunctional donor having at least three reactive functional groups; and (ii) a Michael or conjugate addition reaction with at least one multifunctional acceptor having at least three reactive functional groups.

[0135] In one embodiment, the multifunctional donor and the multifunctional acceptor each comprise at least one trifunctional, tetrafunctional, pentafunctional, or hexafunctional reactive group.

[0136] In another embodiment, the donor is an amine or a thiol, or a mixture of both. The donor is a mixture of at least one difunctional or polyfunctional thiol and at least one difunctional or polyfunctional amine. The amine is a difunctional primary amine, a polyfunctional primary amine, a difunctional secondary amine, or a polyfunctional secondary amine. The amine comprises C2-C... 20Aliphatic chains, C4-C7 cyclic rings, or C4-C7 heterocycles.

[0137] According to another embodiment, the crosslinked polymer includes poly-β-amino ester, poly-β-thioester, or copolymers thereof.

[0138] Non-limiting examples of bifunctional or polyfunctional amines include 4,4'-trimethylenepiperidine (TMPP), isophorone diamine, bis-(aminomethyl)cyclohexane, cyclohexane diamine, piperazine, aminoethylpiperazine, bis-aminonorbornene, diethylenetriamine, diethylenediamine, tetraethylenepentamine, hexamethylenediamine, diaminopropane, diaminobutane, decanediamine, dodecanediamine, and polyethyleneimine.

[0139] Another embodiment discloses that the donor is a mixture of one or more thiols and one or more amines, and that the amine functional group (NH) is present in an amount of about ≤50%, ≤25%, or ≤20% of the total molar equivalent of the thiols and amine functional groups (SH and NH).

[0140] In various embodiments, the acceptor is selected from acrylates, methacrylates, maleates, fumarates, itaconic acid esters, malonates, crotonates, citrates, maleimides, or mixtures thereof. Preferably, the acceptor is an acrylate. The acceptor may be (i) an acrylate, diacrylate, or polyfunctional acrylate of an epoxide; (ii) an acrylate, diacrylate, or polyfunctional acrylate of a polyurethane; or (iii) an acrylate, diacrylate, or polyfunctional acrylate of a polyether; or a combination thereof.

[0141] Non-limiting examples of the receptor functional group are selected from trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, or acrylates, diacrylates, or polyfunctional acrylates of polyesters. Receptors may also include bifunctional acrylates.

[0142] Another implementation discloses that the donor-receptor combination also includes a bifunctional amine, a trifunctional amine, a tetrafunctional amine, a pentafunctional amine, or a hexafunctional amine. These can be secondary or primary amines.

[0143] Another embodiment discloses a crosslinked polymer comprising a combination of β-amino esters and β-thioesters, wherein the β-amino esters are present in an amount of about ≤50 mol equivalents, ≤25 mol equivalents, or ≤20 mol equivalents of the total molar equivalents of the thioesters and amino esters.

[0144] Therefore, four non-limiting general routes or embodiments for the practical application and implementation of the polymer shell microcapsules of the present invention are described below, which are capable of encapsulating and retaining lipophilic goods, including examples of erosive goods such as fragrances or volatile oils, while the polymer shell is also biodegradable according to the standards described herein, and is made via a process that avoids the need for high temperatures and / or the need to use or remove volatile substances or other undesirable solvents or reagents during the encapsulation stage. The four processes are:

[0145] (i) Prepolymer route: Polyester or copolyester or poly-β-amino ester or poly-β-thioester prepolymer route with or without in-situ crosslinking, branching or chain extension in the oil-in-water microencapsulation stage.

[0146] (ii) PLGA prepolymer route: a mild solvent-mediated prepolymer route using PLGA polymers with or without in-situ crosslinking, branching or chain extension during the oil-in-water microencapsulation stage.

[0147] (iii) In-situ emulsion polymerization route: In-situ emulsion polymerization of monomeric reactants or precursors (diols / diacids) to form a polyester or copolyester shell around the cargo. Therefore, in-situ emulsion polymerization involves the condensation or esterification of monomeric reactants to form a polymer shell comprising an aliphatic polyester. The monomeric reactants are (a) at least one bifunctional or polyfunctional acid, acyl chloride, ester, or anhydride; and (b) at least one bifunctional or polyfunctional alcohol or polyol. The in-situ condensation reaction of the monomeric reactants is carried out at a temperature equal to or ≤100°C, ≤95°C, or ≤80°C to form the aliphatic polyester polymer shell. The catalyst is a sulfonic acid, phosphoric acid, or other acid, tin octoate, tin hexanoate, stannic acid or stannic acid derivatives, tin oxides or tin-based compounds, or a lipase or other enzyme.

[0148] (iv) Poly-β-amino esters and / or poly-β-thioesters via in-situ oil-in-water addition polymerization: In-situ oil-in-water addition polymerization of monomeric reactants or precursors (donors / acceptors) forms a poly-β-amino ester and / or poly-β-thioester shell around the cargo. The monomeric reactants comprise (i) at least one bifunctional thiol, polyfunctional thiol, bifunctional amine, or polyfunctional amine donor, and (ii) at least one bifunctional or polyfunctional Michael acceptor. For more demanding applications or cargoes, the in-situ reaction is carried out between (i) trithiols, tetrathiols, pentathiols, or hexathiols; and (ii) triacrylates, tetraacrylates, pentaacrylates, or hexaacrylates. Therefore, the method can additionally utilize a free radical initiator system added to the aqueous, oil, or two-phase phases at the start, partial completion, or near completion of the in-situ reaction. In this method, a polymer is added as a powder or solution to an aqueous or oil phase, wherein the polymer is selected from aliphatic polyesters, chitosan, cellulose, cellulose-based compounds, and proteins.

[0149] Therefore, within the scope of the process and / or compositional variations, embodiments, descriptions, and practical examples of the microcapsules of the present invention, it will be understood that they are capable of being used in many types of lipophilic goods and in many media or applications (formulated final products include products in anhydrous or solid form or solvent-based products or formulations, or in aqueous formulation media at neutral or near-neutral pH), and do indeed function in delivering certain fragrances and / or other goods that are more easily encapsulated or retained and / or stored, while also exhibiting biodegradability or non-durability. However, in some cases, such biodegradable microcapsules may not meet the most demanding requirements while retaining their biodegradability because certain fragrances or strongly solvated or plasticizing goods are retained in formulated liquid product media at pH values ​​significantly away from neutral (such as pH 3) and / or in the presence of certain aggressive surfactants or other ingredients, as may be encountered in liquid fabric conditioners or certain solvent-based formulated final products. Many examples of uncrosslinked biodegradable polymer shells may not meet the most demanding combinations. In fact, some less cross-linked, branched, or chain-extended polyesters that do exhibit evidence of biodegradability or non-persistence, and that do indeed enable capsules to demonstrate a certain degree of stability in some final formulations and release certain cargo properties, may not do so in the most demanding combinations of storage or delivery media (external corrosivity) and / or combinations of strongly plasticizing flavorings or cargo interiors (internal corrosivity). In such demanding cases, capsule shells with high cross-linking densities may be required to stably maintain the cargo during storage under these conditions.

[0150] In another embodiment, the lipophilic core is selected from agrochemicals, aliphatic esters, antimicrobial agents, antifungal agents, antifouling agents, antioxidants, antiviral agents, biocides, catalysts, cosmetic actives, dyes, colorants, detergents, edible oils, moisturizing oils, essential oils, fats, fatty acids, fatty acid esters, food additives, fragrances, flavorings, hair care actives, halogenated compounds, hydrocarbons, pesticides, insect repellents, lipids, lipophilic scale inhibitors, mineral oils, oral care actives, organic solvents, organic esters, chlorinated solvents, pesticides, perfumes, preservatives, skin care actives, UV absorbers, vegetable oils, and combinations thereof, or any active ingredient (whether lipophilic or not) dissolved in or miscible with one or more of these lipophilic cores listed herein to form a core. The lipophilic core or product is preferably a fragrance, perfume, or essential oil.

[0151] When designing capsule shells for the most demanding applications, such as fragrances encapsulating liquid fabric conditioner products, higher crosslinking densities and / or some other form of rigidity and solvent / chemical resistance, or resistance to more extreme pH values, are typically required. This usually means the ability to achieve a significant fragrance uplift (containment) or release upon physical crushing or via other triggering factors, which is considered highly advantageous for such products. Furthermore, the capsule must, of course, remain "intact" because it contains the fragrance (note that fragrance is a "corrosive solvate or plasticizer" compared to many other things) and remains inside for a relatively long time until such crushing or other triggered release occurs during (consumer) use. More specifically, the capsules typically also need to be stable ("intact") when stored before the end consumer's final use of the formulated product, potentially with extreme pH values ​​such as pH 3, and / or for extended periods, and / or contain solvents or ingredients that may have a damaging effect on the polymer shell wall. As mentioned above, existing examples of capsule technologies reported to meet such demanding requirements are melamine-formaldehyde (M-Fs) and cross-linked acrylates.

[0152] These capsules form durable, rigid shells, exhibiting long-term storage stability in formulated aqueous media (such as at pH 3), and typically contain surfactants, as is the case with some liquid fabric conditioner products, all of which contain “corrosive” goods (fragrances). However, as also described in the prior art above, these MF or acrylate or related capsules are not biodegradable in aqueous media such as seawater, river / surface water, or activated sludge, according to recognized international standards (such as EN / ISO, ASTM, OECD, etc.), and they are also not compostable. Furthermore, it is not easy to make such highly cross-linked capsule shells biodegradable while maintaining performance (fragrance enhancement) or storage stability. This invention discovers a route to manufacture stable capsules (e.g., storage stability before use) that are resistant to solvation or plasticizing / softening from within (fragrance cargo) and to the effects of formulation components that may be at an aggressive pH of 3 and / or contain a mixture of surfactants (from the “external” formulation medium), but which also show evidence of biodegradation or lack of persistence in water-based media (aqueous systems) and still function, for example, as a fragrance enhancer (when the fragrance is cargo) upon triggering.

[0153] In another implementation, microcapsules are used in household care (laundry products, cleaning products), personal care (hair, skin, oral products), and industrial sectors (such as coatings, adhesives, agricultural products, energy markets), and others. Therefore, many different formulations or usage environments are encountered.

[0154] In another embodiment, it is disclosed that the microcapsules are stable as core-shell capsules in aqueous slurries, in water-based formulations, or in solvent-based formulations. The microcapsules are also storage stable as core-shell capsules in solid formulations or printed products. Water- or solvent-based formulations can be in a pH range of about 3 to 11, 3 to 6, 6 to 8, or 8 to 11.

[0155] In another embodiment, the microcapsules of the present invention are formulated into laundry detergents, fabric softeners, fabric conditioners, shampoos, hair conditioners, liquid soaps, solid soaps, skin deodorants, skin moisturizers, skin conditioners, hair or skin protectants, detergents, disinfectants, cleaning solutions, dishwashing liquids or dishwashing sheets, detergent powders or sheets or liquids, and cosmetic formulations.

[0156] In one specific embodiment, the microcapsules are used in fabric conditioning compositions or laundry detergent compositions.

[0157] The capsules of the present invention, which are biodegradable or non-persistent in water tests and exhibit encapsulation properties, are functional and stable in a variety of formulations, including aqueous formulations or solutions at various pH values ​​and in the presence of various additives (including surfactants or salts), as well as solvent-based formulations or products, and also in the form of dried or anhydrous or low-moisture products (tablets, larger capsules, powders or powder mixtures, gels). In manufacturing or formulating such products, the capsules of the present invention can be incorporated directly as a slurry produced by this production process or added as a dried product (e.g., the capsules can be spray-dried, freeze-dried, fluidized bed-dried, or dried by any other drying process to prepare dried capsules). Examples of spray drying are given below, for example, for preparing free-flowing powders or for preparing coated capsules.

[0158] To address the most demanding requirements regarding stability in certain formulations, or in solvents, or in water-based formulations far from neutral pH, as mentioned above, one possible approach is to manufacture polymers with higher crosslinking densities, but using polyesters (or other biodegradable polymer chains) as the main component of the polymer shell, particularly potentially biodegradable or non-persistent polyester chains. However, it is well known to those skilled in the art that conventional crosslinking typically slows down or inhibits the biodegradation process.

[0159] We unexpectedly discovered that some particularly highly cross-linked structures (such as capsule shells) that have achieved even higher cross-linking densities can still exhibit evidence of hydrolysis or biodegradability in combinations that provide stable capsule (containing "holding" performance and storage stability in aqueous formulations) or show signs of non-persistence over time when biodegradability tests are performed in aqueous media. In some cases, the use of hydrolyzable or cleavable cross-links can surprisingly achieve combinations of stable capsules that are stable in storage in aqueous formulations but can exhibit biodegradability in aqueous environments or test media.

[0160] Such materials that demonstrate evidence of biodegradability in aquatic environments are also compostable.

[0161] For fragrance encapsulation via in-situ polymerization, creating crosslinked networks through reactions requiring high temperatures (such as condensation reactions between acids and alcohols) is inconvenient—undesirable if encapsulating volatile or reactive goods such as fragrances in situ. Michael addition is another known route for achieving crosslinking at moderate temperatures. Typically, an amine (primary or secondary) or thiol donor reacts with an acceptor under mild conditions. The acceptor is usually a molecule with conjugated double bonds, such as acrylates, methacrylates, itaconic acid esters, maleates, fumarates, or maleimides. This typically results in the formation of polyurethanes (Aza-Michael reaction) or polythioesters (Thio-Michael reaction).

[0162] However, we have also found that polymer shells, hybrids, or copolymers containing both amino ester and thioester moieties in the crosslinked network can be designed to have enhanced stability at pH values ​​far from neutral, compared to similar polyamino ester polymers themselves. By selecting appropriate combinations of multifunctional components, robust capsules can be made to encapsulate fragrances, while also being storage-stable and biodegradable or exhibiting non-persistence in water or other environments or media.

[0163] Furthermore, we have found that this method can surprisingly achieve high cross-linking densities during capsule manufacturing [which is necessary in some applications to enhance or containment performance, and also necessary for storage stability in aqueous formulations that may be considered aggressive (destabilizing) at their pH and / or when using surfactants], yet remain biodegradable or non-durable in aqueous media after use, as demonstrated by OECD or other tests. Such (storage) stable cross-linked capsule structures for the most demanding encapsulation can be formed using trifunctional or multifunctional reactants in an in-situ Michael reaction—and these capsule shells thus formed remain biodegradable or non-durable in aqueous media.

[0164] For achieving sufficient crosslinking of materials for certain applications, the required crosslinking can be achieved, for example, by using two or more functional reactants with a functionality of 3 or higher, for a combination of storage stability in relatively corrosive (e.g., far from neutral pH, optionally containing surfactants and / or salts) aqueous media, fragrance retention in terms of performance, and retention of biodegradability or non-persistence over a longer period after use. These are thus specified as A3+B3 or A3+B4, etc. Other (lower functionality) reactants may also be present. For applications requiring a more robust shell, it is preferred that at least one of the multifunctional reactants has three or four or more reactive functional groups. More preferably, both multifunctional reactants will have three or four or more reactive functional groups—in order to obtain a capsule that produces fragrance retention and is stable in fabric conditioning agents and similar low-pH media.

[0165] Therefore, we have found that these disadvantages associated with some uncrosslinked or low-crosslinked capsule shells, such as sensitivity to more plasticized goods, storage sensitivity to more plasticized goods, and / or sensitivity to corrosive formulated final products, while still maintaining biodegradability or possible non-persistence as described herein, can be addressed by the described alternative approach, namely, the use of high-functionality reactants [e.g., using A3 and B3 monomers, i.e., having trifunctional or more functional groups in each of at least two of the reactants]. Described herein as an embodiment of the invention is an in-situ oil-in-water encapsulation in an oil phase using multifunctional donors and multifunctional acceptors via Michael addition polymerization, wherein other functionalities (lower functionalities such as difunctionality) are optionally also present. The main advantage of this approach is that it allows for the selection of more lipophilic donor and acceptor monomers and includes monomers (acceptors and donors) with higher functionality, which in turn reduces the risk of residual monomer excess and ensures the acquisition of capsules with high crosslinking density and appropriate retention and stability, or can be more easily customized. Furthermore, early gelation is limited by dilution (solventization) in cargoes (oils, fragrances, or other hydrophobic cargoes).

[0166] In another embodiment, the polymer microcapsule shell of the present invention is biodegradable or compostable in an aqueous or solid medium. The aqueous or solid medium is selected from activated sludge, secondary treated effluent, river water, surface water, freshwater, seawater, soil, and compost.

[0167] Another embodiment of this application discloses that the polymer microcapsule shell material of the present invention exhibits a biodegradability of at least 20% in an aqueous medium when measured by OECD test methods 301, 302, or 306. The polymer microcapsule shell material shows signs of biodegradation within 120 days, 60 days, 40 days, or 28 days.

[0168] For the most demanding aqueous media used to store or deliver capsules, such as pH 2 or 3 or pH 11 or 12, a higher crosslinking density is preferred. Surprisingly, however, the resulting capsules may be biodegradable or non-durable, according to OECD or other standard tests. Preferably, more than 50 mol%, more preferably more than 60 mol%, more preferably more than 70 mol%, 80 mol%, or 90 mol% of the composition is trifunctional or higher.

[0169] For many monomer combinations, in-situ oil-in-water polymerization can produce core-shell morphologies, and if the degree of crosslinking is high enough (donors and acceptors with higher functionality), it produces stable capsules with good fragrance retention and / or good long-term stability and / or fragrance release (burst) after deposition on fabrics (including cotton samples used for testing) and through frictional breakage.

[0170] For in-situ polymerization processes, thiols and / or amines (as well as other donors and acceptors) with lower water solubility are preferred donors in some embodiments compared to, for example, common polyfunctional aliphatic amines or more water-soluble thiols. They tend not to partition into the aqueous phase during the relatively rapid polymerization (reaction) phase. For this reason, there are more candidates for polyfunctional thiols, but some polyfunctional amines are also suitable, as they have relatively low water solubility or hydrophilicity and are more significantly present in the oil phase (where cargoes and other reactants are also present). Tetramethylpiperidine (TMPP) is an example of a low-water-soluble polyfunctional amine, but any other amine that substantially does not partition into the aqueous phase can be used.

[0171] Compared to interfacial polymerization, a potential drawback of in-situ polymerization is the limitation on the use of relatively highly water-soluble reactants (monomers). While interfacial polymerization requires such a monomer (for one of the monomers), when a highly water-soluble monomer (donor or acceptor) is used in in-situ oil-in-water polymerization, where all reactants are in the oil phase, it may partition into the aqueous phase and therefore not fully participate in the in-situ polymerization (which occurs in the oil phase). In some cases, this can limit network structures and restrict the formation of more robust shells. This may result in the inability to form core-shell or soft capsules, partial collapse of the capsule structure, or a more open (loose) structure or base type of capsule structure, which typically performs poorly in terms of robust cargo retention or storage stability.

[0172] We have discovered routes to overcome this problem in some systems where in-situ oil-in-water polymerization is used and a more water-soluble (partially distributed) donor (or acceptor) molecule is required, for example, to control biodegradability and thus incorporate it into the capsule shell structure. Therefore, in another embodiment, any amine (including hydrophilic amines) can be incorporated into the capsule shell polymer by pre-reacting the amine with a multifunctional acceptor (e.g., multifunctional acrylates or itaconic acid esters) via Michael addition, either in bulk or in the presence of an oil carrier, such that most or all of the NH bonds are capped via the pre-reaction with the acceptor molecule. This essentially forms a new acceptor in situ containing the amine-derived moiety and can be further reacted in a subsequent Michael addition reaction (the in-situ polymerization stage, where the cargo is present with the remaining reactive monomers). If desired, this can be carried out sequentially in the same reaction vessel. Then, an in-situ polymerization stage is carried out with another donor, typically a less hydrophilic option such as a multifunctional thiol, and wherein the total stoichiometry is preferably largely matched such that the double bond acceptor group now hanging from the amine from the first reaction step will react with all the newly added donor groups such as thiols, wherein the addition is made in a ratio of approximately 1:1 to the total stoichiometry of the donor and acceptor molecules throughout the structure.

[0173] In this way, by carrying out such a pre-reaction, it is possible to produce hybrid Michael addition polymers of poly-amino esters-co-thioesters (or copolymers of β-amino esters and β-thioesters) via in-situ oil-in-water polymerization, wherein all reactants (including amines, even aqueous amines) are in the oil phase. This is beneficial for fine-tuning biodegradability and capsule performance in terms of fragrance release holding tests and fragrance storage stability, even at pH values ​​deviating from neutral. The pre-reaction of water-soluble amines can be incorporated into the process as a first step [alone or integrated (one-pot)], as a precursor step for the entire process. In some cases, a similar effect can also be achieved for the amine donor by preparing oligoamides with amine end groups (prepared in reactions with bifunctional or polyfunctional acids or acid derivatives via excess amine functional groups), thus preparing precursor adducts in which the amine is slightly chain-extended via amide formation or other reactions to prepare molecules with poor water solubility containing the amine moiety, but in this case, the amide bond is present and the amine (NH) group is retained (for subsequent reactions in the subsequent in-situ reactive polymerization stage).

[0174] Unbound by theory, it is proposed that more biodegradable shells prepared from β-thioesters can be produced via the binding of polyamine donors (forming β-amino ester moieties with hybrid or copolymer structures of β-thioesters), and / or via selecting more hydrophilic or unstable polyfunctional amines for this step.

[0175] Similarly, all other things being equal, the lower overall functionality of all donors and acceptors from the polymerization (determined by the overall total multifunctionality of the system) results in a relatively lower crosslinking density, which may lead to a more biodegradable shell.

[0176] In most cases, the total stoichiometry is preferably maintained at approximately 1:1 or 1:1 in terms of the total donor and acceptor reactive (functional) group equivalents. It can be soluble in small or large variations, although smaller variations are preferred, and for example, within about 20 or 10 mol equivalent %, or within 5 mol equivalent %, or within 1 mol equivalent %.

[0177] In the use of the Michael addition reaction method, a mixture of thiols and amines can be advantageously used as donors to fine-tune the balance between biodegradability and encapsulation properties or storage stability, including at neutral pH or far from neutral pH (such as pH 3 or 11), and included in formulated products such as liquid fabric conditioners / softeners, shampoos, soaps, deodorants, skin creams, insect repellents, cleaning solutions, disinfectants, agricultural surfactants, etc.

[0178] In another embodiment, this application provides a method for preparing microcapsules comprising a polymeric microcapsule shell prepared from β-thioester and β-aminoester functional groups, the method comprising: a) pre-reacting a bifunctional or polyfunctional amine with a bifunctional or polyfunctional acrylate; b) preparing an oil-in-water emulsion of (i) an oil phase and (ii) an aqueous phase, optionally adding at least one additive to the oil phase or the aqueous phase, the oil phase comprising the product of (a) and any remaining acceptor, mixed with a bifunctional or polyfunctional thiol, and at least one lipophilic core, optionally mixed with a diluent; the aqueous phase comprising at least one stabilizer or emulsifier; c) forming a polymeric microcapsule shell wall by in-situ oil-in-water Michael addition polymerization of the donor and acceptor reactants; and d) obtaining a core encapsulated in the polymeric microcapsule shell.

[0179] It should also be understood that the capsules of the present invention, by any embodiment or variation, can be dried or formulated into coated or bilayer capsules. This can further improve storage stability and / or further improve performance. Bilayer, multilayer, or overcoated microcapsules comprise hydrogels or cross-linked alginate. Examples of these concepts are further described below. The average diameter of the microcapsules of this application is about 100 nm to 100 μm, although the distribution can exceed this range, and the capsules can be made larger if desired. A more typical average particle size range is about 1 μm to 100 μm. The particle size can be varied by changing the reaction conditions and relative concentrations. All the examples below are within these ranges.

[0180] Furthermore, certain aspects of this application are described in detail through the following embodiments. The embodiments given herein are for illustrative purposes and are not intended to limit the scope of the application. Figure 1-12 Optical micrographs of examples of microcapsules prepared using various polymers and via the various methods described are shown. Figure 13-16 Sensory test results of aroma release from microcapsules prepared via the various methods described are shown. Figure 17 and 18 Biodegradation data for microcapsule shell materials prepared by the various methods described are shown.

[0181] In these routes, firstly, a prepolymer is synthesized or taken, which optionally has reactive functional groups as end groups and / or distributed along the chain. The polymer is then used for a subsequent microencapsulation process, which can be a sequential process in the same container as the prepolymer synthesis or later in a new container. In these cases, microencapsulation is carried out via the initial dissolution of the prepolymer in the cargo, optionally with the addition of a diluent (together forming an oil or organic phase), typically with heating, followed by emulsification of the oil phase with an aqueous phase, and then cooling or allowing the functional groups that may be present in the prepolymer to react via self-reaction (e.g., free radical polymerization or crosslinking) or with added co-reactive agents to form chain extensions and / or branching and / or crosslinking during encapsulation. Any aliphatic polyester that is soluble or solubilized in the oil phase (with or without diluent) during the encapsulation (oil-in-water emulsion) stage and is biodegradable once a shell is formed can be used. However, some aliphatic polyesters, such as those with reactive functional groups for crosslinking or chain extension, or those with high (above 25 or 30°C or higher) Tg, or those that form crystalline domains upon cooling, are preferred for more robust capsules. Typical reactive functional groups are vinyl-type reactive functional groups that react with diepoxides for in-situ linear chain growth (e.g., in acrylates / methacrylates, acrylamides, methacrylamides, etc.) or epoxy acids (e.g., acid or anhydride-terminated prepolymers (e.g., bifunctional groups in acid-terminated groups), or polyfunctional epoxides for in-situ crosslinking via acid-epoxide reactions. Other combinations of reactive groups are also feasible, such as hydroxy(diol)-isocyanates (bifunctional or polyfunctional) and all related variants. As another embodiment, reversible or non-covalent crosslinking or pseudo-chain extension can be achieved by using added di... The process involves the use of divalent or polyvalent bases (such as oxides of magnesium, calcium, aluminum, barium, etc.), which form complexes or ion / salt interactions with the acid end groups. A key aspect of such methods, which establish molecular weight or introduce intermolecular interactions during the encapsulation stage or add crosslinking or branching during encapsulation, lies in the combination of prepolymers used for chain extension or linkage or crosslinking and / or additives used during encapsulation for in-situ chain extension (e.g., bifunctional epoxides with polyester-diacids) or crosslinking (polyfunctional epoxides with di or polyfunctional acids), and in ensuring that the polymer shell remains biodegradable after the reaction or interaction that forms the capsule shell is complete.

[0182] In another embodiment, a method for preparing the microcapsules of claim 1, the method comprising: a) preparing an oil-in-water emulsion (i) an oil phase and (ii) an aqueous phase, the oil phase comprising a polymer or prepolymer and at least one lipophilic core; the aqueous phase comprising at least one stabilizer or emulsifier; b) optionally adding at least one catalyst or at least one initiator to the oil phase; c) optionally heating the oil-in-water emulsion to a temperature of 25°C to 100°C under stirring; d) forming a polymer microcapsule shell by cooling or by in-situ reaction of the polymer or prepolymer in the oil-in-water phase; and e) obtaining a core encapsulated in the polymer microcapsule shell; wherein the polymer or prepolymer formed is an aliphatic polyester or poly-β-amino ester or poly-β-thioester, or copolymers or terpolymers thereof, or combinations thereof.

[0183] The prepolymer of this application may contain unsaturated groups at the chain ends or have unsaturated groups distributed along the chain, and the in-situ reaction to form the polymer shell includes the reaction of the prepolymer containing unsaturated groups via (i) chain extension reaction, (ii) branching or (iii) crosslinking reaction.

[0184] The prepolymer contains or has conjugated unsaturated groups distributed along the chain ends, and the in-situ reaction that forms the polymer shell includes a Michael addition reaction of the prepolymer containing conjugated unsaturated groups via (i) chain extension, (ii) branching or (iii) crosslinking with a bifunctional or polyfunctional amine or a bifunctional or polyfunctional thiol.

[0185] The prepolymer contains or has reactive acid or anhydride groups distributed at the chain ends, and the in-situ reaction includes the reaction of at least one acid or anhydride group of the prepolymer via (i) chain extension, (ii) branching or (iii) crosslinking with at least one bifunctional or polyfunctional epoxide or bifunctional or polyfunctional amine.

[0186] Embodiments of the invention via the prepolymer route

[0187] Embodiments of the present invention are described, wherein microcapsules having a lipophilic core and a biodegradable polymer shell are prepared as follows: - an oil-in-water emulsion comprising, for example, an aliphatic polyester polymer or prepolymer prepared by polycondensation and an oil phase of lipophilic cargo, optionally with the addition of a diluent or solvent and / or by the application of heat, optionally with the addition of a catalyst or initiator to one phase, forming the capsule shell wall by cooling or by in-situ reaction of the prepolymer or polymer, and obtaining microcapsules encapsulating cargo.

[0188] The diluent will preferably be a liquid at room temperature, or readily melt at a moderate temperature such as below 90°C or below 50°C, and may be a hydrocarbon oil, alkane, molten wax, ester oil, fatty acid ester, aliphatic ester, or hydrocarbon carbonate ester. Some specific examples include mineral oil, long-chain alkanes such as hexadecane, aliphatic esters such as long-chain esters such as caprylate, myristate, oleate, cocoate, palmitate, or stearate, including isopropyl myristate as an example, or long-chain esters of short-chain acids or other mono- or poly-esters.

[0189] If the prepolymer contains unsaturated reactive groups, the initiator is preferably a free radical initiator, which may be a peroxide, an azo radical initiator, a redox system such as a persulfate system, or a photoinitiator for UV-induced free radical reactions.

[0190] Example 1: Synthesis of polyester prepolymer (bulk polycondensation)

[0191] Polycondensation is typically carried out under vacuum at temperatures of 130-230°C for several hours or days to achieve an increase in molecular weight, usually exceeding 2,000 g mol. -1 For polyesters whose aliphatic backbones are all derived from diacids and glycols, a typical polyester synthesis procedure is described below. In some embodiments, a total molar ratio of diacid to glycol of 1:1 is used, although this total stoichiometry (diacid: glycol) can also be designed and adapted to introduce acid-rich or hydroxyl-rich end groups through variations in the feed monomer stoichiometry (excess acid leads to acid-rich end groups; excess glycol leads to hydroxyl-rich end groups). Other end-capping procedures for such polymers are also described below if needed. Different times and / or temperatures are also used in the examples. Diesters or acyl chlorides or anhydrides can also be used instead of acids, although the use of acyl chlorides, which can be used in principle, is generally preferred to be avoided for many applications.

[0192] Numerous glycols, diacids, or acid derivatives exist that can be used in combination to prepare polyester prepolymers and compositions, possessing initial compatibility with fragrances or oils, reactive characteristics (self-reactivity or co-reactivity with added reagents), or other functionalities for chain extension, branching, crosslinking, or other linkages, and / or crystallinity allowing the formation of capsules with integrity to encapsulate such goods, and biodegradability, particularly in aqueous environments, after capsule formation (in some cases meeting OECD testing standards). This allows for fine-tuning of goods compatibility (initially required before capsule formation), the stability of dispersions or emulsions in water, and (after capsule formation) biodegradability and retention of goods over time. If desired, water dispersibility and / or biodegradability can be further improved by including citric acid, glycerol, oligomeric polyethylene glycol, or other polyester precursors with relatively high hydrophilicity.

[0193] Then, during the in-situ oil-in-water encapsulation stage, microcapsules are prepared from this pre-made polyester (polyester prepolymer) via an in-situ oil-in-water encapsulation process, either directly or after additional end-capping with reactive end groups or intrachain groups, and then again directly via an in-situ oil-in-water encapsulation process (see further below - Example 5) (conducted sequentially in the same vessel or as a separate step), optionally accompanied by chain extension or branching or crosslinking.

[0194] Polyesters with mixed aliphatic backbones were synthesized using succinic acid (SA), dodecanoic acid (DA), dodecenylsuccinic anhydride (DSA), and ethylene glycol (EG) in the form SA(0.5)-DA(0.25)-DSA(0.25)-EG(1), where parentheses indicate molar ratios. Other variations are indicated below and / or in the tables.

[0195] Succinic acid (SA; 0.5 eq, 48.3 mmol, 5.708 g), dodecanoic acid (DA; 0.25 eq, 24.16 mmol, 5.565 g), dodecenylsuccinic anhydride (DSA; 0.25 eq, 24.16 mmol, 6.437 g), ethylene glycol (EG; 1 eq, 96.64 mmol, 6.000 g), and p-toluenesulfonic acid (p-TSA; 0.01 eq, 0.96 mmol, 0.166 g) as a catalyst were added to a 250 mL round-bottom flask connected to a condenser and a vacuum pump, and stirred to melt at 145 °C. Once melted, the vacuum was slowly increased over several hours to remove water generated by the polycondensation step (minimum 100 mbar). Depending on the target molecular weight (MW), the reaction continued for several hours to 3 days. The analysis of the obtained polyester was performed by SEC in THF (tetrahydrofuran size exclusion chromatography) and acid value titration, both on small samples of the reaction product. For this example (reaction time approximately 24 hours; refer to ENC 2188), the MW (THF SEC) data for the polyester prepolymer was: Mw = 5200 gmol / L. -1 Mn is 2800 gmol -1 The Mw / Mn ratio is 1.84.

[0196] Then, after introducing crosslinking to the capsules with glycidyl methacrylate (GlyMA) end-capsulation, microcapsules were prepared from this polyester prepolymer (SA(0.5)-DA(0.25)-DSA(0.25)-EG(1)) (Example 5). (See below). The synthesis of this polymer was repeated on a larger scale (about 100 g; refer to ENC 2207) with similar product properties and different end-capsulation methods, and then used to manufacture capsules.

[0197] The tables or examples below further illustrate a range of other prepolymers as examples [some of which were subsequently end-capped (see below) and then used for microencapsulation]. Variations in reaction time and temperature, as well as catalyst selection, are shown. For example, FASTCAT 4100 (butylstannic acid) was used as a catalyst in many examples. Other catalysts, such as other tin or organometallic catalysts, sulfonic acids, or phosphoric acid, may be used.

[0198] Example 2: End-capping of condensation prepolymer

[0199] Selective end-capping of polyester prepolymers with acids or hydroxyl groups can be designed by altering the stoichiometry of the diacid-diol reaction in the above-described process. Excess diacid will result in diacid-rich end-capping in the prepolymer. Diacid end-capping can then be achieved, for example, by reacting with epoxy-functionalized reagents or other reagents having functional groups that will co-react with carboxylic acids under moderate temperature conditions to induce chain extension or crosslinking during the oil-in-water in-situ encapsulation stage. Similarly, diol end-capping can be achieved by reacting with isocyanate or anhydride-functionalized reagents or other reagents having functional groups that will co-react with hydroxyl groups under moderate temperature conditions to induce chain extension or crosslinking during the oil-in-water in-situ encapsulation stage.

[0200] At the end of the initial (1:1) polycondensation, diacid-terminated groups can be introduced into the prepolymer by reacting a 1:1 (diacid / diac alcohol) prepolymer with an anhydride (e.g., succinic acid, dodecenylsuccinic acid, octenylsuccinic acid, maleic anhydride, etc.), while maintaining or slightly increasing the prepolymer's molecular weight (MW). When an excess of diol or diacid is used from the start of the polycondensation reaction, this capsulates the hydroxyl groups with the acid and avoids or reduces some side reactions that might occur to lower the MW (if undesirable).

[0201] Other reactive end-capping (or in chain reactive groups – see below) can be introduced onto the polyester prepolymer, for example via the introduction of reactive double bonds, such as in acrylates or methacrylates or itaconic acid esters or citraconic acid esters or other reactive vinyl groups. Other reactive groups (or combinations thereof, such as acid end-capping for reaction with epoxy functional agents) can also be used for crosslinking and / or chain extension reactions, which facilitates in-situ encapsulation in the presence of the cargo.

[0202] Double bonds can be introduced by reacting polyester end groups with acrylic acid or methacrylic acid or other acids with vinyl bonds, glycidyl methacrylate or hydroxyethyl acrylate / methacrylate, methyl hydroxyacrylate, hydroxypropyl acrylate or hydroxybutyl acrylate, acrylamide, methacrylamide or other functional (hydroxyl, amine, isocyanate, epoxy, acid, ester, acyl chloride) acrylate, methacrylate, acrylamide or methacrylamide or other active molecules containing double bonds.

[0203] In the presence of acid and / or hydroxyl end groups, end-capped polyester chains with double bonds can be achieved via an exemplary reaction with glycidyl methacrylate (GlyMA). The epoxide ring (glycidyl group) can react with the acid end group and possibly with the hydroxyl group, thereby introducing vinyl groups into the prepolymer chain ends. The vinyl bonds on the prepolymer can react with other similar vinyl-end-capped chains in the same product mixture and / or with different vinyl-functionalized polymers (self-crosslinking) to allow slight crosslinking during capsule production in the presence of flavorings or other goods. These double bonds can also undergo addition reactions, such as chain growth and / or crosslinking with thio-Michael reactions or amine reactions (aza-Michael reactions) (see examples later). This can introduce hydrolyzable or biodegradable crosslinks or branches onto or between biodegradable polyester prepolymers. Examples of typical procedures for forming capsules from prepolymers with vinyl end groups are further given below.

[0204] Therefore, after end-capping with, for example, glycidyl methacrylate (GlyMA) of varying weight percentages, capsules are encapsulated in the presence of goods (e.g., fragrances, oils, waxes, butters, or other lipophilic goods) by in-situ crosslinking or chain extension of polyester.

[0205] Example 3: End-capping of polyester prepolymer with glycidyl methacrylate (GlyMA)

[0206] Below is an example of end-capping a polyester with glycidyl methacrylate (GlyMA) via reaction with acid-terminated groups (primarily via acid-terminated groups, but possibly via hydroxyl groups). The progress of the carboxylic acid-epoxy end-capping reaction can be tracked by acid value (AN) titration; a decrease is evidence of this end-capping. This, along with analysis of residual GlyMA and the presence of glyceryl monomethacrylate (GMA, a byproduct) (both quantified by liquid chromatography (LC),) ensures monitoring of the end-capping reaction. As the reaction with GlyMA proceeds, more and more acid groups are end-capped, and the acid value should decrease. GMA is the ring-opening counterpart of GlyMA and is formed during the ring-opening / hydrolysis of unreacted GlyMA (its level, along with the polymer acid value, is an indicator, for example, of the consumption of GMA in the end-capping reaction).

[0207] Following the above procedure, a polyester prepolymer was prepared via bulk polymerization from succinic acid (SA), dodecanoic acid (DA), dodecenylsuccinic acid (DSA), and ethylene glycol (EG) (see above) (SA(0.5eq)-DA(0.25eq)-DSA(0.25eq)-EG(1)). The acid value of the polyester prepolymer was 20 (=20mg KOH / g polyester prepolymer product; this is equivalent to 0.00036 moles of acid per 1g polyester; 6.000g=0.0021 moles of acid in 6g prepolymer product). Then, GlyMA (0.300g (=0.0021mol), triethylamine (0.027g, 0.01eq of polyester) and hydroquinone (0.030g, 0.01eq of polyester) were weighed into a 50mL round-bottom flask connected to a condenser and a vacuum and placed in an oil bath at 120°C. Once melted, the reaction The mixture was kept under rapid stirring and high vacuum for 3 hours. The end-capped polyester prepolymer was analyzed by liquid chromatography (LC) to determine the residual GlyMA and GMA monomers. The acid value was determined by titration. This product, along with other end-capped products, can be used directly for microencapsulation (reacted in the same reactor) or stored for later use. Crosslinking or chain extension reactions can be carried out during the in-situ oil-in-water encapsulation stage, with the vinyl end groups already in place, via direct heating or the addition of a free radical initiator (oil-soluble or water-soluble) (see below).

[0208] Example 4: End-capping of polyester prepolymer with methacrylic acid (MAA)

[0209] Furthermore, the above polyester prepolymer (194-03-1; (SA(0.5eq)-DA(0.25eq)-DSA(0.25eq)-EG(1)) was end-capped with 0.25 molar equivalents of methacrylic acid (MAA). 0.28 g of methacrylic acid was added to 3 g of the previously described SA-DSA-DA-EG polymer. 14 mg (0.01 molar equivalents) of hydroquinone was added as an inhibitor. The molten polymer and methacrylic acid mixture was stirred at 120 °C for two hours to perform end-capping, thereby introducing methacrylate end groups.

[0210] Two other polyesters (188-34 and 188-35) containing SA (0.95 or 0.9), DSA (0.05 or 0.1), and ethylene glycol (1.2) were synthesized using a similar method as described above (therefore, SA-DSA-EG (0.95 / 0.05 / 1.2; and 0.9 / 0.1 / 1.2)). The molecular weights of the initially uncapped polyester prepolymers were 2700 gmol. -1 and 2000gmol -1The goal of these polymers is to have -OH-rich end groups (excess diol) to facilitate subsequent end-capping with methacrylate functional acids (methyl methacrylate) as described above. Subsequently, 0.1 molar equivalents of methacrylic acid (50 mg to 2.4 g) were added to each prepolymer. 10 mg of hydroquinone was added to the reaction mixture to inhibit polymerization. The reaction mixture was heated to 120 °C and the molten polymer-MAA mixture was stirred for 3 hours. The levels of residual MAA were determined by GC to be 610 ppm and 1155 ppm, respectively. Mw increased slightly, likely due to further condensation (chain extension) at these temperatures, reaching 3600 gmol, respectively. -1 and 3000gmol -1 .

[0211] Other polyester prepolymers for screening for biodegradability potential can be prepared by modifying these procedures, as shown in the examples and related tables herein, in terms of the diacid-diol combination and relative ratio, reaction time and temperature, catalyst type (all for polycondensation), and different end-capping methods. Commercially available polyester acrylate prepolymers (or oligomers), such as those sold by Sartomer / Arkema or other companies, can also be used.

[0212] Example 5: Microencapsulation-radical polymerization with or without unsaturated end groups using condensation prepolymers

[0213] The following describes an example of a procedure for microencapsulating goods such as fragrances or oils using biodegradable polyester prepolymers that optionally have reactive end-capping or intrachain reactive groups or no reactive groups. Although the steps of (a) prepolymer formation, (b) optional end-capping, and (c) microencapsulation are described herein, it is clear that this sequence can be a continuous process (always using the same reaction vessel if desired) or as separate steps.

[0214] These initial embodiments illustrate a method for preparing microcapsules by encapsulating fragrance materials with a prepolymer having vinyl (unsaturated) end groups (e.g., acrylates or methacrylates) and a radical reaction of the vinyl groups, such as those prepared in the embodiments above.

[0215] Other encapsulation methods are further described below, such as using different reactive end groups or combinations, including unsaturated groups, intrachain reactive groups, or Michael addition reactions without reactive groups (without crosslinking or chain extension) (see examples below).

[0216] Examples 5A-5E: Preparation of vinyl-terminated polyesters via free radical reaction of unsaturated groups (vinyl groups). Examples of microcapsule preparation

[0217] Example 5A: A microencapsulation procedure for a slurry in the presence of 30% w / w fragrance to form microcapsules is described. Example.

[0218] In a 50 mL plastic beaker, 1 g of the polyester prepolymer (SA(0.5)-DA(0.25)-DSA(0.25)-EG(1)) with methacrylate end groups as described above and 1 g of fragrance were homogenized to obtain a clear brown liquid (organic phase) (and warmed from room temperature to 70 °C). In a separate beaker, 1.34 g of Poval (8.89 wt%) and 4.26 g of water were stirred for 10–15 minutes in the presence of 0.03 g of ammonium persulfate (APS). The aqueous phase was added to the organic phase and stirred for 10–15 minutes. The slurry (10 wt% prepolymer; 30 wt% fragrance) was then homogenized for 2 minutes at 4200 rpm using a Silverson mixer (in small quantities). The reaction vessel was then placed in an oil bath and heated at 70–80 °C for 3 hours with stirring. In some cases, emulsification was observed. In this case, 0.0075g of xanthan gum is added while the slurry is heated to prevent agglomeration. This forms microcapsules containing fragrance.

[0219] Example 5B: In another similar experiment, using the same polymer and oil phase as in Example 5A, Poval (0.759 g, 11.8 wt.% solution to make a final wt.% of 1.5), water (5.211 g to make a total slurry of 10 g), and the free radical initiator ammonium persulfate (APS; 0.03 g, 3 wt%) were added to a 50 mL plastic beaker. All of these were weighed and then homogenized for 30 seconds at 4200 rpm using a Silverson mixer. The organic phase (the same as in 5A above; (warm polyester with fragrance)) was then added to the mixture and homogenized further for 60 seconds using the same settings, before being added to a 30 mL glass jar (reaction vessel) with a stir bar. The reaction vessel was placed in an 80°C oil bath with stirring for 3 hours, during which capsules formed, in which the vinyl end groups or a portion thereof underwent free radical crosslinking.

[0220] Capsules easily form again and can be seen under an optical microscope. Liquid cargo is also clearly expelled when the capsules are crushed, and flavoring release is detected.

[0221] Example 5C: In another embodiment using the SA(0.5)-DA(0.25)-DSA(0.25)-EG(1)ENC 2188 sample, the polyester was capped with 0.25 eq GlyMA (relative to the total acid in the prepolymer synthesis) after reacting at 120°C under vacuum for 3 hours.

[0222] The microcapsules formed by the same method just described in 5A and 5B (in-situ free radical polymerization in the presence of fragrance) can then be observed under an optical microscope, showing a fragrance loading of 27% by weight. Other persulfates (potassium persulfate, such as KPS) or other water-soluble or redox initiators can be used in the free radical polymerization (encapsulation) stage.

[0223] Example 5D (microcapsule ENC2223): In another set of experiments, once the SA(0.5)-DA(0.25)-DSA(0.25)-EG(1) (ENC 2207) polymer (ENC2207) was formed, it was further reacted with added acid anhydride (dodecenyl succinic anhydride, DSA, 0.1 equivalent; reacted in the same vessel at 120°C and vacuum for 3 hours) to generate acid-terminated groups in the polyester prepolymer (the acid value AN increased, and some polycondensation also occurred to slightly increase MW). This prepolymer (ENC 2216) was then end-capped with GlyMA (again at 120°C and vacuum for 3 hours) to obtain a vinyl (methacrylate)-end-capped polyester (ENC2211; the decrease in AN indicates end-capping with methacrylate), which was then used to manufacture microcapsules with 30 wt% fragrance added to the reaction vessel. The resulting microcapsules (ENC 2223) contained 22 wt.% fragrance loading. Furthermore, LC (liquid chromatography) analysis confirmed the presence of very low levels of GlyMA (11 ppm) and GMA (81 ppm) in the slurry product. An overview of the procedures is provided in Table 1 below.

[0224] Table 1: Examples of polyester compositions used in the microcapsules of Example 5 (MW data obtained by GPC)

[0225]

[0226] Example 5E: In another set of experiments, an SA(0.7)-DA(0.3)-EG(1) prepolymer (ENC 2139) was prepared according to a similar procedure to that described above and reacted with 2 wt% GlyMA to prepare another methacrylate-terminated polymer, which was then used in the process (as described when using an APS initiator) to prepare microcapsules in the presence of fragrance during an oil-in-water process. The fragrance encapsulation amount of various end-capped samples of this polymer (sample IDs (respectively) ENC 2198, 2199, and 2200) ranged from 24 to 32 wt%. Unreacted GlyMA was measured at 158 ​​ppm, and byproduct GMA was measured at 132 ppm – for ENC 2200, 32 wt% fragrance was found encapsulated within the slurry or released from the capsule.

[0227] In the above embodiments, LC was used to detect GlyMA and GMA, and it was concluded that, based on the residual GlyMA and GMA (glyceryl monomethacrylate, a hydrolysis product of GlyMA) content after microencapsulation, a conversion rate of >99% was typically achieved. These values ​​were even lower when using less GlyMA.

[0228] Further examples include microcapsules formed similarly from polyester prepolymers, GlyMA-terminated prepolymers, and then crosslinked during in-situ encapsulation of the fragrance via an oil-in-water process (all of these prepolymers subsequently capped with GlyMA).

[0229] Example 5F: Microencapsulation of condensation prepolymers - free radical polymerization without unsaturated end groups

[0230] In some cases, capsules were also surprisingly successfully manufactured, in which the prepolymer was prepared via the same method as described above and subsequently subjected to an oil-in-water encapsulation process, but without initiator-induced crosslinking (no free radical initiators were used and no end-group modification was required, and an emulsion encapsulation method similar to that described above was used after the preparation of the prepolymer), and the following composition was employed:

[0231] Ref 2324: SA(0.5)-DA(0.4)-DSA(0.1)-cyclohexanediethanol 1:1;

[0232] Ref 2323: SA(0.7)-Sebacic acid(0.2)-DSA(0.1)-EG(1); and

[0233] Ref 2329:SA(0.5)-DA(0.40)-DSA(0.10)-EG(1).

[0234] In some cases, capsules containing flavorings (as an example of erosive plasticized goods) can be surprisingly made without crosslinking, wherein the pre-formulated polymer used for the capsule shell exhibits a certain melt conversion (Tm of the prepolymer) and is therefore semi-crystalline or has crystalline domains, and wherein the Tm is above ambient temperature (>15°C or >20°C) and preferably above (>) 30°C, more preferably above 35°C or 40°C or 45°C or 50°C or 55°C or 60°C, or above 60°C or 65°C or 70°C or 75°C or 80°C or 85°C or 90°C or 95°C or 100°C, as long as the polymer remains soluble or melt-dissolved or partially dissolved in the goods, optionally with the addition of a diluent or compatibilizer or polymer. In this scenario, after melting polyester and / or other polymers with fragrance to form a melt solution, an aqueous phase is then added using the described method to form an emulsion, followed by gradual cooling. This causes some crystallization of the polymer shell surrounding the fragrance, thus forming a capsule shell around the fragrance without crosslinking and still exhibiting signs of biodegradation or non-persistence. Crosslinking and / or chain extension and / or branching may also be performed if desired, but in some cases, this is not necessary for forming a shell that can retain the fragrance. The melting point or conversion, and the associated crystallinity or crystalline domains, can be fine-tuned by the conditions or rate of cooling, the presence of additives, and / or by compositional changes in the prepolymer structure, including, for example, incorporating amide or urethane bonds into the backbone of the polyester polymer, which can contribute to obtaining a higher melting point, if desired or deemed beneficial. The degree of bonding of these groups is the extent to which the thermal dissolution process of the goods can still be completed.

[0235] The capsules, prepared by cooling and / or optionally crosslinking and / or chain extension in a slurry or dispersion, can then be dried, which may contribute to further crystallinity development and / or the formation of pseudo-crosslinking points via hydrogen bonding. Similarly, in some cases, intentional annealing may be performed, for example by controlled heating and / or cooling, to help form crystalline domains within the capsule shell; in others, they may be redispersed in water as needed. Drying can be accomplished by simple air drying, controlled air heating, vacuum drying, or via spray drying or other known particulate capsule drying processes. The capsules may also be coated with an outer layer (of the same or different material as the shell material) during or after this drying process.

[0236] The ability to encapsulate a variety of lipophilic cargoes (not just fragrances, which are known to be more plasticizing or aggressive among cargoes) within uncrosslinked and crosslinked polyesters allows for fine-tuning of biodegradability for different cargoes and / or for different end-use formulations (some cargoes are also less aggressive than others in their tendency to attack the polyester shell wall). More stringent requirements for end-use formulations and / or cargoes may necessitate some crosslinking and / or some crystalline domains within the polyester shell to suit the end-use while still retaining some biodegradability.

[0237] The ability to encapsulate a variety of lipophilic goods (not just fragrances, which are known to be more plasticizing or aggressive in goods) in both uncrosslinked and crosslinked polyesters allows for tailored biodegradability formulations for different goods and / or purposes (some formulations are also less aggressive than others in terms of their tendency to attack the polyester shell wall). For more demanding end-use formulations and / or goods, some crosslinking and / or some crystalline regions in the polyester shell may be required to suit the end-use while still retaining some biodegradability.

[0238] It is recognized that fragrances, natural oils or essential oils, and other lipophilic goods have different tendencies to solubilize or attack polymer shell walls, and many are often mixtures of various chemical components, and these components and their ratios in the product vary by grade or product. Therefore, in some cases, it may be necessary to tailor the design of polyester prepolymer compositions, their crystallinity (if present), and / or their degree of crosslinking, for specific fragrances or other lipophilic or oil / diluent-soluble goods, so as to allow the polyester prepolymer to be soluble or miscible or compatible with the goods when heated or warmed, but to transform into an insoluble solid capsule shell wall upon cooling (at ambient temperature) or upon completion of the encapsulation conversion process. Therefore, insolubility or capsule wall formation / solidification can be achieved by crystallization or the formation of other insoluble solid domains and / or crosslinking and / or pseudo-crosslinking, such as via hydrogen bonding (through, for example, amides or urethanes that can co-link), and / or via the addition of divalent or polyvalent bases such as calcium oxide or magnesium oxide complexed with the acid groups of the polyester, or via in-situ chain extension increasing the molecular weight or linking polymers or oligomers.

[0239] Typically, microcapsules are imaged using an optical microscope before and after crushing the diluted dispersion with a glass slide. The images before and after crushing look distinctly different; uncrushed microcapsules are spherical, while crushed microcapsules show complete deformation and are no longer fragrance, indicating the release of fragrance / oil cargoes. Therefore, optical microscopy reveals the presence of capsules that can be crushed to release fragrance from these polyester capsules.

[0240] Example 6: Polyester prepolymer with intrachain reactive groups (Example: Itaconic acid ester polymer)

[0241] As an alternative to end-capped prepolymers, polyesters are made from unsaturated diacids or diols and can therefore be used directly (without end-capping) to prepare cross-linked capsules. Examples of unsaturated diacids that can be used in this method include maleic acid, fumaric acid, itaconic acid (IA), citraconic acid, etc.

[0242] For the sample designated RD201-16: succinic acid (SA; 0.425 mol eq, 12.74 g), itaconic acid (IA; 0.075 mol eq, 2.48 g), 1,6-hexanediol (HD; 0.5 mol eq, 15.000 g), hydroquinone (50 mg), and butylstannic acid (Fastcat 4100; 0.003 mol eq, 70 mg) were added to a 250 mL round-bottom flask connected to a condenser and vacuum pump and melted at 160 °C with stirring. Once melted, the vacuum was slowly increased over several hours (minimum 100 psi) to remove water generated from the polycondensation step. The reaction continued for 6–24 hours, depending on the target molecular weight (MW). MWD was determined by SEC (THF as the mobile phase, relative to polystyrene standards), and after 24 hours, Mw was 54.7 kgmol. -1 With D = 3.2, Tg and Tm were determined by DSC (2 heating / cooling cycles, -80°C to 100°C, 10°C / min), yielding Tg and Tm values ​​of -47.8°C and 37.5°C, respectively (for RD201-16; SA(0.85)-IA(0.15) / 1,6HD(1.0)). For a similar polymer prepared using the following composition: SA(0.95)-IA(0.05) / 1,6HD(1.0) (Ref RD201-13), Mw was 54.4 kgmol after 24 hours at 160°C. -1 The Tm was measured to be 44.7 °C by DSC. A series of variations can be made using different itaconic acid ester contents and different diols and / or other diacids (or their derivatives) to fine-tune the hydrophobic-hydrophilic balance of the double bond content and / or chain structure. Examples of some other polymers synthesized (all catalyzed by butylstannic acid and polycondensed at 160 °C for 24 or 8 hours) are further given below.

[0243] Example 7: Free radical polymeric prepolymer with intrachain unsaturated groups for microencapsulation - Polyesters with itaconic acid ester functionality (similar concepts would also apply to maleate, fumarate, citrate (and side-suspended intrachain acrylates or methacrylates, etc.) are encapsulated using itaconic acid ester polyesters via free radical crosslinking and / or chain extension with an oil-soluble initiator. An example of such a method is described below:

[0244] 1 g of polyester prepolymer (201-16-1:SA(0.85)-IA(0.15) / 1,6HD 1 / 1 – prepared as in Example 6 above) was melted into 4 g of fragrance at 60 °C and stirred. 50 mg of Vazo 67 (an oil-soluble free radical initiator) was added and dissolved. An aqueous phase was added to the oil or organic phase: 1 g of a 10% Poval solution in water / 5% HMHE C (Natrosol 330 plus CS) / 10% PVP K120 was added and stirred for 16,000 seconds. -1 The emulsion was homogenized with IKA Ultraturrax for 30 seconds. During homogenization, 7.3 g of 1% Poval 40-88 was slowly added, and the mixture was heated to 50°C. The resulting emulsion was homogenized for 120 seconds. The emulsion was then heated at 80°C for 2 hours while stirring and slowly cooled. This formed fragrance-core microcapsules. Hexane washing was used to remove free or weakly adsorbed oil / cargo to determine the amount of encapsulated and free fragrance.

[0245] Similar procedures are used for other polyesters, for example:

[0246] Ref 201-13:0.95SA-0.05IA / 1.00HDD;

[0247] Ref 201-10:0.85SA-0.1-DSA-0.05IA / 1.00HDD, and

[0248] Ref 201-22:0.75SA-0.25IA / 1.00HDD, etc.

[0249] Example 8: Preparation of unsaturated groups without the addition of free radical initiators or co-reactant crosslinking Polyester microcapsule shells containing double bonds such as methacrylates or itaconic acid esters

[0250] At 60°C, 1g of polyester 201-16-1 (SA(0.85)-IA(0.15) / 1,6HD (total diacid: glycol = 1:1) was melted into 4g of fragrance and stirred. 1g of 10% Poval in water / 5% HMHEC (Natrosol) was then added. TM A solution of 330 (plus CS) / 10% polyvinylpyrrolidone (PVP K120) was used as a stabilizer, and IKA Ultraturrax was used. TM In the 16,000s -1 The mixture was homogenized for 30 seconds. During homogenization, 7.3 g of 1% Poval 40-88, heated to 50°C, was slowly added to the fragrance-polymer melt mixture (at approximately 60°C). The resulting emulsion was homogenized for 120 seconds. The emulsion was then slowly cooled with stirring. Microcapsules with the fragrance core were formed.

[0251] Note: No free radical initiator was used in this embodiment, and the capsules are still easily formed via this simple process and retain the fragrance as is. A similar procedure is used with other polyesters, such as 201-13 (0.95SA / 0.05IA / 1.00HD) and 201-10 (0.85SA / 0.1DSA / 0.05IA / 1.00HD). While not bound by theory, some self-reaction may occur during that stage of the process, within the chain and / or as end groups of unsaturated groups, to undergo some chain extension or branching or mild crosslinking, which contributes to encapsulation and may in this case contribute to the capsule stability of some goods. Crystallinity may also be present and promote this effect.

[0252] Variations include, for example, the use of added hydrophobically modified silica (HM silica), which is added together with PVP K 120 and polyester, followed by the addition of a water-POVAL solution along with fragrance and homogenization of the entire mixture, again using a crosslinking step without initiator induction. This is used for polymer 201-13-1, with the composition: 0.95SA / 0.05IA / 1.00HD.

[0253] Other microcapsules are similarly prepared from polyester prepolymers with unsaturated groups, with or without the addition of free radical initiators, but with some variations as noted below. Examples are:

[0254] 201-30-3: SA(0.75)-IA(0.25)-1,12DDO(1.0), prepare the prepolymer as described, then add Poval after preparing the prepolymer and stir at 80°C for 2 hours (without initiator).

[0255] 201-30-4: Same as 201-30-3 above, but with the addition of Vazo 67 radical initiator (stirred at 80°C for 2 hours). Molecular weight increased significantly (GPC, capsule shell dissolved in THF), but the level of crosslinking or chain extension was not high because all materials were soluble in THF used for GPC analysis. Compared to the similar capsules prepared without the initiator (201-30-3), the 201-30-4 capsules (with the added radical initiator) showed excellent flavor retention, although the biodegradability was slightly lower, but still significant.

[0256] 196-52-1, 196-53-1, 196-54-1: Capsules were prepared according to the same procedure using polyester prepolymer 201-17-1 (SA(0.75)-IA(0.25)-1,8-octanediol(1.0)) with added PVP (K120, provided by Ashland LLC) and POVAL and Sipernat 50S stabilizer (40-88) as raw material, and R14-3913 fragrance as cargo.

[0257] Other examples of polymer compositions used for the successful preparation of flavor-in-the-box (ENC) microcapsules are listed in the table below.

[0258] Table 2: Various microencapsulated polyester preforms used in the described embodiments or in the tables below and / or other tables below. polymer Composition of instances

[0259]

[0260]

[0261] Table 3: Experimental results of microencapsulation of parent polyester prepolymers with or without reactive end-group functional groups. Regulations

[0262]

[0263]

[0264] Table 4: Use of parent prepolymers (some from Table 2, some with repeated or varied conditions or additives) for products with... Examples of microencapsulation experiments on polyester compositions with intrachain reactive end-group functional groups.

[0265]

[0266] Remark

[0267] DA or DDA: Dodecanoic acid; DSA: Dodecenylsuccinic anhydride; OSA: Octenylsuccinic anhydride; SA: Succinic acid; LGA: D,L-lactide-glycolic acid; EG: Ethylene glycol; p-TSA: p-Toluenesulfonic acid; HD: 1,6-Hexanediol; APS: Ammonium persulfate (water-soluble free radical initiator); V 67: Azo 67 (oil-soluble free radical initiator); BDO: 1,4-Butanediol; IA: Itaconic acid; DDD: Dodecanool; Glycyrrhizic acid (GMA): Glycidyl methacrylate; GMA: Glycidyl methacrylate; PVA: Polyvinyl alcohol; N330: Natros alcohol TM 330+HMHEC (hydrophobic modified hydroxyethyl cellulose); BSA - butyl stannic acid; NM - not measured.

[0268] Example 9: In-situ polymerization-encapsulation via addition reactions (substitution radical crosslinking, grafting or branching or expansion) Capsules are formed by crosslinking and / or chain extension of itaconic acid ester polyester (prepolymer).

[0269] In addition to the free radical crosslinking of itaconic acid ester groups or other double bonds such as acrylate or methacrylate end groups as described above, during the emulsion encapsulation stage, itaconic acid esters (or other polyesters containing double or triple bonds) can be crosslinked, branched, chain extended, and / or functionalized with side chains (dangling chains) via a free radical approach or via an addition reaction, depending on the double bond content and the stoichiometry with the added co-agent. This addition reaction can be carried out by adding a nucleophilic reagent (also known as a donor) such as a thiol or amine. For example, a monofunctional thiol (or secondary amine) will be added to create dangling side chains on the double bonds. This may be beneficial for further fine-tuning of hydrophobicity-hydrophilicity and / or aiding in the deposition (or affinity) of the capsule onto (or affinity for) surfaces or materials, such as clothing materials (laundry applications), surfaces to be cleaned with household cleaners, or hair or skin. Bifunctional or polyfunctional thiols (or primary amines or bifunctional secondary amines or polyfunctional primary or secondary amines) will form crosslinks or branch from the double bonds, and the relative degree of linear chain extender, branched polymer, or crosslinked polymer domain will be determined by the number of itaconic acid esters (or other intra- or extra-chain) double bonds in each polyester and the functionality of the donor (amine or thiol). This ratio design can lead to in-situ (encapsulation stage in the presence of the cargo) chain extension, a common variation produced by prepolymers, which can allow higher molecular weight linear or substantially linear or grafted polymer shells away from the double bonds if these double bonds are located at or near (if not exactly at the chain ends) the polyester chain ends and / or the grafted polymer shell. Higher functional thiols or amines can be used to introduce branching and / or crosslinking. This approach can result in relatively low or relatively high crosslinking of capsule shell wall structures to ensure plasticization that captures and / or retains volatile cargoes while still unexpectedly preserving evidence of biodegradability.

[0270] The level of crosslinking that occurs will vary depending on the backbone chain structure, the crosslinking method / mechanism (including other reagents added to enhance or limit crosslinking), and the nature of the fragrance and other components that may be present.

[0271] Various mixing methods of these embodiments are certainly feasible. In particular, mixtures or blends of linear and cross-linked chains (intentionally prepared in situ, and / or prepared via post-synthetic blending or mixing) can be formed during capsule shell manufacturing, thereby ensuring that biodegradability can be further fine-tuned. Alternatively, monofunctional (dangling functional groups) and polyfunctional additives (for controlling cross-linking) can be used to fine-tune hydrophobic balance and / or deposition properties.

[0272] In prepolymers such as polyesters or low-polyesters, the use of addition reactions such as Michael addition (addition of a thiol or amine reagent to the double (or triple) bond (whether it be (meth)acrylate, itaconic acid, citrate, maleate, fumarate, maleimide, or others)) can produce mildly or more highly crosslinked systems to ensure that biodegradability is retained in the crosslinked system. For example, thiols or amines, which can be hydrophobic or hydrophilic, can be used to crosslink polyesters with suitable double or triple functional groups. When these unsaturated bonds react in such addition reactions, such as with thiols (thio-Michael reaction) or amines (aza-Michael reaction) to extend and / or branch and / or crosslink, hydrolyzable or biodegradable crosslinks or branches can be introduced into or between biodegradable polyester prepolymers functionalized with unsaturated groups within and / or at the chain ends. Using hydrophilic agents (e.g., those with PEG (polyethylene glycol) or other hydrophilic chains) to crosslink the double bonds in polyesters creates a hydrophilic environment around the crosslinking bonds, further promoting their hydrolysis or biodegradation. Other chains with thiol or amine groups that are easily degraded or hydrolyzed can be used as crosslinking agents for polyesters or other prepolymers (melted or dissolved in fragrances; then emulsified or dispersed and encapsulated).

[0273] At 60°C, 1g of polyester prepolymer 201-27-1 (SA(0.75)-IA(0.25) / 1,6HD (total diacid: glycol = 1:1) was melted in 4g of fragrance and stirred. 1g of a solution of 10% Poval in water / 5% HMHEC (Natrosol™ 330 plus CS) / 10% vinylpyrrolidone (PVP K120) was added and the mixture was incubated for 16,000 seconds. -1 IKAUltraturrax TM Homogenize for 30 seconds. During homogenization, slowly add 7.3 g of 1% Poval 40-88 heated to 50°C to the fragrance-polymer melt mixture (approximately 60°C). Maintain at 60°C with stirring and adjust the pH of the continuous phase to 9. Add 90 mg of 2,2'-(ethylenedioxy)diethylthiol (0.5 molar equivalent relative to itaconic acid ester) and stir the mixture at 60°C for 2 hours, followed by slow cooling. Microcapsules form in the fragrance-containing slurry.

[0274] Other thiols can be used. Amines or diamines can also be used instead of thiols for crosslinking, branching, and / or chain extension in these Michael addition reactions. Other conjugated or active carbon double bonds can also be used instead of itaconic acid esters. When crosslinking is performed using this method, "spacers" are created between the crosslinks, and hydrolyzable bonds are also formed at the crosslinking points—this method helps control the impact of crosslinking on biodegradation while ensuring that the cargo is retained in the capsule shell. Other methods for introducing hydrolyzable crosslinking points or chain extensions or branching (e.g., via epoxy-acid or anhydride reactions) are further described below.

[0275] Example 10: Encapsulation of polyester using other chain extension reactions

[0276] In a 250 mL flask equipped with a stirrer, condenser, vacuum connection, and collection container, 10 g (0.0846 mol) of succinic acid (approximately 20% molar excess relative to glycol), 4.376 g (0.0705 mol) of ethylene glycol, and 0.02 g of sulfuric acid as a catalyst were added. The mixture was stirred at a reduced pressure of 10 mbar while being gradually heated to an internal temperature of 120 °C and allowed to react for 120 minutes (Ref ENC-1673).

[0277] The reaction mixture of 10.163 g of polyethylene glycol (PSA-EG, MW 2800 g / mol) was transferred as is to a 100 mL glass jar equipped with a magnetic stir bar, followed by the addition of 13 g of triacetin, 6.5 g of Waglinol oil, and 6.5 g of Spring Garden fragrance. Diglycidyl ether (DGE) was then added at room temperature. The addition of DGE was to facilitate in-situ chain extension (potentially branching and / or mild crosslinking) during capsule encapsulation by forming other ester (hydroxy-ester) groups from the acid chain ends of the PSA-EG backbone, through the reaction of the carboxylic acid end groups with the epoxy groups of DGE. 78 mL of water was introduced into the flask and the slurry was homogenized at 4000 rpm using an IKA homogenizer. The reaction mixture was gradually heated to an internal temperature of 80 °C, and the triethylamine (TEA, added dropwise) catalyst was added at 80 °C with magnetic stirring for 2.5 hours. The slurry product (ENC 1707) was centrifuged and air-dried overnight in a running fume hood. Clearly defined 5-10 micrometer capsules were formed, and a clear release of the cargo was observed when pressed under a microscope slide, confirming that the flavor-Waglinol mixture was retained at 50-60%. Other bifunctional or polyfunctional epoxides, including epoxides of vegetable oils (such as epoxidized soybean oil, which can also introduce branching or crosslinking to fine-tune biodegradability-encapsulation efficiency and retention), can be similarly used in reactions with acid- or anhydride-functionalized polyester prepolymers. Chain extension or branching or crosslinking is influenced by the epoxy-acid (or anhydride) reaction and generates hydroxyl-ester bonds as hydrolyzable (degradable) branching or crosslinking sites, which can detach from or remain with the biodegradable polyester prepolymer. A higher proportion of acid end groups can be introduced by reacting the polyester prepolymer with an acid or anhydride (e.g., succinic anhydride or maleic anhydride, or acid) (or via a slightly stoichiometric excess of a diacid relative to the initial polyester formation reaction) at the end of the initial polyester formation reaction. Similarly, anhydride or acid-functionalized vegetable oils or another precursor can react with epoxy or hydroxyl-functionalized polyester prepolymers. Other routes for the hydrolytic (degradable) crosslinking of biodegradable polyester prepolymers compatible with the goods are as described above, for example via Michael addition.

[0278] Example 11: Similar fragrance-free capsules (for biodegradation testing)

[0279] For biodegradability testing, similar fragrance-free polyester particles were synthesized to eliminate any influence of aromatic oils on the final biodegradability results; their components were classified as readily biodegradable. As an example, 1 g of polymer was melted at 60°C. Vazo was then melted at 60°C. TM 67, along with 1g of the Poval / HMHEC mixture, was added to the melt polymer and treated with IKAUltraturrax. TMIn the 16,000s -1 Homogenize for 30 seconds. During homogenization, slowly add 7.3 g of 1% Poval40-88, heated to 50°C. Homogenize the resulting emulsion for 120 seconds. Then heat the emulsion at 80°C with stirring for 2 hours and allow it to cool slowly. All biodegradation tests were performed according to OECD, ASTM, ISO, EN, or relevant methods, sometimes with longer runs, and a reference compound (as specified in the test method used) was always used to ensure compliance with test conditions. Biodegradation tests can also be performed on capsules of reference goods with known inertness (e.g., silicone oil) or actual fragrance goods, and blank tests were also performed using the goods at the tested encapsulation level (where both BOD results were subtracted accordingly and the concentration adjusted to the capsule shell concentration).

[0280] Example 12: Biodegradation Test

[0281] This is typically performed according to OECD methods. For example, various methods such as OECD 301D, 301F, 302B, and 306 are used, some with extended timelines. Samples insoluble in aqueous media usually require the development of a suitable dispersion or form for testing. In some cases, EN 14852:2018 or EN ISO 14851:2004 can be used, which involves running the test in an aqueous medium for 6 months (this test, along with other methods mentioned above, is mentioned in the ECHA draft to avoid microplastic problems). Inoculum and suitable water (secondary treated effluent, surface water, seawater, or activated sludge) are used, supplied from a local source (such as a wastewater treatment plant). The mineral culture medium and inoculum specified by the OECD 301D method are added to deionized water, followed by aeration for 20 minutes, and then the sample polymer sample is added at a concentration of 4–10 mg / ml, depending on the predicted biodegradability.

[0282] In some instances, biodegradation is monitored by measuring dissolved oxygen levels. In others, the test is conducted in freshwater using inoculum supplied by a local water treatment plant. This test simulates the environment in which these polymers would be exposed after passing through a freshwater wastewater treatment plant. A readily biodegradable sodium benzoate reference is used as a positive control. All samples are tested in duplicate. Measurements are taken at intervals of approximately 7 days to at least 28 days, and in many cases, more than 28 days. Exemplary data are given in the table below. For example, after 28 days, a polyester (SA(0.5)-DA(0.25)-DSDA(0.25)–EG(1.0); ENC 2188) was found to be 16% biodegradable, but this degradation was significant over time, doubling by day 120, providing reasonable evidence of non-persistence in the environment. The table below summarizes some exemplary tests of the biodegradability of polyesters in aquatic environments (OECD 301D, surface water / secondary treated effluent). Such polymers can be used to encapsulate fragrances, etc., according to one or more methods described herein. For example, in the OECD 301F test, higher and / or faster levels of biodegradation in activated sludge were expected in all cases.

[0283] Table 5: Biodegradability test results of exemplary capsule shells (301D, surface water)

[0284]

[0285] Please note that 188-86-1 included here is an example of a polyester that does not meet the inherent or predominantly inherent biodegradability criteria and therefore did not show sufficient evidence of its biodegradability in this test, as its biodegradation had not yet begun by day 28. However, it can be seen that it does indeed biodegrade thereafter, so it is reasonable to expect it to be non-persistent, although more testing is generally required to support this. Longer testing periods and / or testing in activated sludge, soil, or compost can be employed. While not bound by theory, the polyester is a particularly highly hydrophobic polyester with its high alkyl side chain (DSA) content.

[0286] Biodegradability and fragrance compatibility can also be fine-tuned by adjusting the hydrophilic-hydrophobic balance, including the level of crosslinking. If a highly hydrophobic polyester (e.g., a polymer prepared solely from DSA-EG (1:1.2, 188-86-1, ENC 2110) and having a relatively high total hydrophobic group content on each ester repeating unit, such as long alkyl side chains (e.g., from DSA i.e., dodecenylsuccinic acid)) is tested, it exhibits a low biodegradability rate (2% after 60 days, according to OECD 301D, surface water), but biodegradation continues to increase (10% at day 120 and increasing), thus biodegradation is slow in surface water but can still be described as non-persistent after a longer or longer period and / or in different test media such as compost or activated sludge. This allows for control of the biodegradability rate. However, replacing some DSA (a highly hydrophobic diacid) with short-chain diacids such as succinic acid (SA) without suspensory alkyl groups (which significantly reduces hydrophobicity) leads to higher degradation rates in the aqueous medium (freshwater), and possibly even higher in activated sludge or compost. For example, the biodegradability of polyester 188-83-1 (ENC 2105 intermediate) with a composition of DSA(0.5)-SA(0.5)-EG(1.2) exhibiting a biodegradability level of 21% at day 60 and 33% at day 120 can be fine-tuned by changing the ratio of DSA (or OSA, i.e., octenyl succinic acid / anhydride, etc.) to SA and / or by using longer-chain or shorter-chain or medium-chain diacids and / or diols. Similarly, the compatibility of fragrances or other goods can be fine-tuned (more hydrophobic alkyl side chains result in greater compatibility with fragrances).

[0287] It is also worth noting that low or controlled crosslinking will have the effect of reducing or slowing down biodegradation, although it may still show signs of biodegradability or non-persistence over time, while increasing the stability of the capsule, which may be helpful for some cargo packaging. 201-15-3(SA(0.85)-DSA(0.1)-IA-(0.05), a particulate dispersion of a polymer containing itaconic acid (IA) and subsequently its oil-soluble free radical initiator Vazo TM Heating to 80°C in the presence of 67 (which crosslinks or extends the unsaturated groups of itaconic acid ester) resulted in less biodegradation compared to an analogue (201-15-2, the same polymer), in which the particles were prepared in the same manner but without a free radical initiator. Surprisingly, however, the crosslinked sample still exhibited biodegradability over time under such mild aqueous conditions. Figure 17 This illustrates the relative biodegradation diagram.

[0288] Therefore, a balance exists, and for some applications where a low but clearly sustained rate of biodegradation is acceptable, and where compatibility with, for example, higher fragrances or other lipophilic goods and / or higher water resistance is also possible, it is still possible to produce a desirable non-durable end product.

[0289] 2. Prepolymer route (polyesters prepared by ring-opening polymerization, such as PLGA polymers)

[0290] Other embodiments of the invention are described, wherein microcapsules having a lipophilic core and a biodegradable polymer shell are prepared by: - ​​preparing an oil-in-water emulsion comprising an oil phase and a lipophilic cargo, and optionally added diluents or solvents and / or heating aids, said oil phase comprising an aliphatic polyester polymer or prepolymer such as that prepared by ring-opening polymerization containing glycolide and / or lactide units; - optionally adding a catalyst or initiator to one phase; - forming the capsule shell wall by cooling or by in-situ reaction of the prepolymer or polymer, and obtaining microcapsules encapsulating the cargo.

[0291] When heated at a moderate temperature such as below 100°C, 90°C, or below 50°C, or at room temperature, the diluent will preferably be a solvent for PLGA or related polymers, and will preferably be some miscible with water, and will be, for example, a hydrocarbon ester such as ethylene carbonate or propylene carbonate, acetone, dimethyl sulfoxide, hydroxy acid, or a hydroxy ester such as methyl lactate, ethyl lactate, or butyl lactate, or an ester having some water miscibility such as triacetylglycerol.

[0292] When the PLGA polymer or prepolymer contains unsaturated reactive groups, the initiator is preferably a free radical initiator, which may be a peroxide, an azo-based free radical initiator, a redox system such as a persulfate-based system, or a photoinitiator for UV-initiated free radical reactions.

[0293] Example 13: The polyester polymer / prepolymer prepared via ring-opening polymerization (ROP) was used for subsequent microencapsulation (the adhesive encapsulation stage described in Example 13).

[0294] Ring-opening polymerization is another route for preparing polyesters. Although it is more restrictive in the choice of starting agents (monomers) compared to polycondensation, it makes it easier to increase the molecular weight and shortens the reaction time.

[0295] Example 13A: ROP induced by EG

[0296] 5 g (34.7 mmol) of D,L-lactide, 4.03 g (34.7 mmol) of glycolide, 0.028 g (0.07 mmol) of stannous octoate, and 0.0011 g (0.017 mmol) of ethylene glycol (EG) were placed in a dry flask equipped with a condenser. The mixture was kept under nitrogen and gradually heated to 150 °C. The reaction mixture was kept at 150 °C for two hours to produce a viscous amber liquid. It was diluted in THF, precipitated in methanol, and dried under vacuum to separate the PLGA polymer (Ref 192-13-1) with a 50 / 50 molar ratio.

[0297] Example 13B: ROP of HEMA-induced PLGA (HEMA-functionalized PLGA)

[0298] 5 g (34.7 mmol) of D,L-lactide, 4.03 g (34.7 mmol) of glycolide, 0.028 g (0.07 mmol) of stannous octoate, and 0.0022 g (0.017 mmol) of hydroxyethyl methacrylate (HEMA) were placed in a dry flask equipped with a condenser. The mixture was kept under nitrogen and gradually heated to 150 °C. The reaction mixture was kept at 150 °C for two hours to produce a viscous amber liquid. It was diluted in THF, precipitated in methanol, and dried under vacuum to separate the PLGA polymer with a 50 / 50 molar ratio and methacrylate double-bond terminal functional groups (Ref 174-63-1; 17457-1).

[0299] Example 13C: ROP of PLGA induced by EG-DSA

[0300] PLGA copolymers, such as those described above and others, may exhibit poor compatibility or solubility in some oils or fragrances. Therefore, the use of added diluents can benefit from promoting compatibility between the fragrance and the polymer, as well as subsequent encapsulation. Compatible polymers can also be added (blended into) or incorporated into ring-opening polymers as a complement or alternative to small-molecule solubilizing diluents. Because ring-opening polymerization imposes greater limitations on the choice of monomers used to manufacture the polymer, the opportunity to fine-tune PLGA compositions to initial compatibility with oils or fragrances is limited, and PLGA and similar polymers exhibit poor compatibility or solubilizing behavior due to the limited choice of ROP monomers. Therefore, added diluents are used to aid initial dissolution or compatibility with fragrances. Adding high loadings of compatibility diluents is not recommended, as they can dilute the cargo and / or potentially dissolve or plasticize the shell polymer if not removed, and evaporative removal is undesirable. However, we have found that by appropriately designing the modified polymer of PLGA, lower or even zero amounts of diluent can be added. One example of this is the use of hydroxyl groups on oil-soluble or fragrance-soluble prepolymers as initiation sites for PLGA polymerization. An example of using polyesters based on dodecenyl succinic acid or anhydrides (DSA) and EG is described below. The presence of DSA-based polyesters and similar molecules soluble in the selected cargo facilitates the solubility of the fragrance in the final polymer, even at low initiator concentrations. Such polymers and other fragrance-solubilizing polymers can also be blended with PLGA or other polymers that are not readily soluble in or incompatible with fragrances or oils. This can help reduce or eliminate the need for adding small-molecule diluents, the presence of which in some cases can plasticize or weaken the formed shell walls. (Note that the initiators or co-initiators mentioned in these contexts refer to those used in ring-opening polymerization reactions to produce prepolymers or polymers—do not confuse them with free radical initiators that can be used as an option in oil-in-water encapsulation (where a shell is formed from the prepolymer / polymer).)

[0301] Synthesis of DSA-EG (1:1 molar equivalent) prepolymer: 2.8 g (45.1 mmol) of EG was mixed with 10.02 g (37.5 mmol) of DSA and loaded into a Dean-Stark apparatus containing 0.16 g (0.9 mmol) of pTSA as a catalyst. The mixture was heated to 190 °C under gradually increasing vacuum and held for 24 hours to produce a Mw of 3,640 gmol. -1 The polymer. This polymer with hydroxyl-terminated groups (Ref 188-59) was then used as an initiator for ROP, as described below.

[0302] DSA-EG (1g, 0.000277mol) and Sn(Oct)2 (0.01eq, 2.77x10) were added. -60.0277 mol of D,L-lactide (100 eq, 0.0277 mol) and 0.0277 mol of L-lactide were placed in a clean, dry round-bottom flask equipped with a stir bar, and then placed in an oil bath at 160 °C (external temperature) and stirred for 3 hours. A hard white solid was formed. The molecular weight (Mw) of the obtained polymer was 24600 gmol. -1 The dispersion is 2.8. This polymer (Ref 188-96-2 / 188-64) is soluble in warm (60-70°C) fragrances, while PLGA itself (with ethylene glycol as the initiator instead of DSA-EG) is not soluble in it.

[0303] Example 13D: ROP of PLGA with PCL group

[0304] 5 g (34.7 mmol) of D,L-lactide, 4.03 g (34.7 mmol) of glycolide, 7.91 g (69.3 mmol) of caprolactone (CL), 0.0014 g (0.04 mmol) of stannous octanoate, and 0.0011 g (0.017 mmol) of hydroxyethyl methacrylate were placed in a dry flask equipped with a condenser. The mixture was kept under nitrogen atmosphere and gradually heated to 130 °C. The reaction mixture was maintained at 130 °C for 3 hours to produce a viscous, amber-colored oil with a Mw of 24,200 gmol. -1 And Mw / Mn is 2.1 (Ref192-14-1).

[0305] Example 14: Micropolymerization using the prepolymer / polymer prepared from the ring-opening polymerization (ROP) polymer of Example 12 Encapsulation

[0306] In these embodiments, the added diluent is used to facilitate encapsulation with PLGA and related polymers prepared by ring-opening polymerization. While prior art also uses added solvents or diluents with PLGA and related polymers, as described in the prior art, they use volatile organic solvents (e.g., DCM) that need to be removed by an evaporation process, which is not suitable for many goods with volatile components. In this invention, examples of added diluents for this embodiment are propylene carbonate, dimethyl carbonate, other alkyl carbonates, glyceryl triacetate, or oils such as Waglinol and various other esters, which can help the fragrance be compatible with the polymer in many formulated final products without needing to be removed to very low levels, and are therefore tolerable or retained in situ. Other such diluents can be used, including certain other esters, other carbonates, ethers, ketones, hydrocarbon oils, etc. Lower diluent addition levels can be accommodated using DSA-EG PLGA and PLGA with PCL groups, which facilitates solvation and can be carried out at lower solvent addition levels.

[0307] Example 14A: ROP capsules prepared by EG-PLGA functionalization

[0308] ENC-2026: EG-PLGA (4g, 2.7wt.%), propylene carbonate (16g, 8.6wt.%), Roc Green Woody fragrance (30g, 16.3wt.%), Poval (12.79wt.%) (6.6g, wt.%), water (100g, 54.2wt.%), APS (ammonium persulfate) (0.32g, wt.%). The EG-PLGA (4g) polymer was dissolved in propylene carbonate (16g) at 70-80°C with stirring. The polymer solution became viscous, and the fragrance (Roc Green Woody (30g)) was added to the flask and stirred for 30 minutes until completely dissolved (organic phase). An aqueous phase was prepared in a separate beaker, in which water (100g) and Poval (12.79g) were stirred for 15 minutes. The organic phase was then poured into the aqueous phase, and the mixture was stirred for 20 minutes. The latex was homogenized using IKA at 4200 rpm and placed in an oil bath at 80°C for 3 hours. The fragrance loading in the slurry was found to be 6.4%, and the fragrance loading in the dried capsules was 33.2% (Ref 188-56-1).

[0309] Example 14B: ROP capsules prepared by HEMA functionalization

[0310] ENC-2008: HEMA-PLGA (5g, 2.7wt.%), propylene carbonate (16g, 8.6wt.%), Roc GreenWoody flavor (6g, 10.6wt.%), Poval (12.79wt.%) (6.6g, 1.56wt.%), water (40g, 71wt.%), APS (ammonium persulfate) (0.32g, wt.%).

[0311] HEMA-PLGA was dissolved in propylene carbonate at 70-80°C. The polymer solution became viscous, and the fragrance was added to the flask and stirred for 30 minutes until completely dissolved (organic phase). An aqueous phase was prepared in a separate beaker, in which water, Poval, and APS were stirred for 15 minutes. The organic phase was then poured into the aqueous phase and stirred for 20 minutes. The latex was homogenized using an IKA at 4200 rpm and placed in an oil bath at 80°C for 3 hours, during which time APS initiated a reaction between the methacrylate end groups of HEMA-PLA. The fragrance loading in the final reaction mixture was found to be 10% (in the slurry) and 29% (on drying) (Ref 188-51-1).

[0312] Example 14C: ROP capsules prepared with DSA-polyester (PLGA functionalized with DSA-EG) - DSA-EG-PLGA microcapsules

[0313] ENC-2034 pre-prepared polyester (DSA-EG; 3.3 g) was dissolved in 10.56 g of propylene carbonate and stirred at 80 °C for 30 minutes. Then, 19.8 g of Roc Green Woody fragrance was added and stirred for 15 minutes (organic phase). An aqueous phase consisting of 52.1 g of water and 22.3 g of 11.8 wt.% Poval aqueous solution was added to the organic phase with stirring.

[0314] The emulsion was homogenized using an IKA mixer at 4200 rpm. The latex solution was placed in an oil bath at 80°C for 3 hours. Because this is a linear polymer and is not cross-linked, this step is not mandatory and can be omitted or shortened, but it may help ensure adequate fragrance dispersion, and xanthan gum can be added if necessary. The fragrance loading in the slurry was measured to be 16.3%, with an efficiency of 90%. After washing the capsules with hexane (to remove any loosely bound or free fragrance), the encapsulation efficiency was noted to be approximately 87% (Ref 188-87-1).

[0315] 3. In-situ emulsion / microemulsion polymerization route from monomeric reactants or precursors.

[0316] These embodiments of the invention demonstrate microcapsules having a lipophilic core and a biodegradable polymer shell by: a) preparing an oil-in-water emulsion comprising an oil phase, cargo, and optionally added diluents or solvents and / or heating aids, and an aqueous phase comprising a di- or polyfunctional acid and a diol or polyfunctional alcohol, and the aqueous phase comprising a stabilizer and / or other additives; b) adding a catalyst to one phase; c) forming a polymer capsule shell wall by in-situ oil-in-water polycondensation (esterification) polymerization of monomeric reactants or other precursors; and d) obtaining cargo encapsulated in the polymer microcapsule shell.

[0317] The catalyst can be sulfonic acid, phosphoric acid or other acid, or it can be tin octoate, tin hexanoate, stannic acid or stannic acid derivatives, tin oxide or tin oxide derivatives or other tin-based compounds, or lipases or other enzymes or compounds capable of catalyzing esterification / condensation reactions.

[0318] The diluent will preferably be a liquid immiscible with water at room temperature or a liquid that melts readily at moderate temperatures such as below 90°C or below 50°C, and may be a hydrocarbon oil, alkanes, molten wax, ester oil, fatty acid ester, or aliphatic ester. Some specific examples include mineral oils, long-chain alkanes such as hexadecane, aliphatic esters such as long-chain esters such as caprylate, myristate, oleate, cocoate, palmitate, or stearate, including isopropyl myristate as an example, or long-chain esters of short-chain acids or other mono- or poly-esters.

[0319] We have discovered that certain uncrosslinked, biodegradable polyester microcapsules can unexpectedly encapsulate aggressive, plasticizing, or solvable lipophilic goods such as fragrances. We have also discovered another method to achieve or demonstrate the same effect, where the polyester itself is manufactured in situ, rather than preparing a polyester prepolymer for subsequent oil-in-water encapsulation (as described above), while the shell wall is formed by in-situ microemulsion polycondensation of its diol-diacid precursors in the presence of the lipophilic goods. Fragrances are used as exemplary goods and known examples of challenging and aggressive substances. Therefore, one-pot oil-in-water emulsion polymerization of acids and diols dissolved in fragrances has also been demonstrated as a route for manufacturing capsules capable of retaining fragrances. Hydrophobic diacids and diols are preferred precursors for this process, but also require a balance between having a non-persistent or biodegradable structure in the environment. The procedure for preparing polyester particles via microemulsion polymerization is known (Barre're, M. and Landfester, K.. Polyester synthesis in aqueous miniemulsion. Polymer 44 (2003) 2833–2841), but this method has not been used to manufacture microcapsules, nor microcapsules of lipophilic goods, nor biodegradable microcapsules of lipophilic goods. Surprisingly, in-situ microemulsion (oil-in-water) polycondensation can be applied to manufacture microcapsules of encapsulated lipophilic goods (in this case, fragrances, but applicable to any oil-soluble component). Surprisingly, this process can be used for such plasticized goods, although with some important modifications.

[0320] Example 15: In-situ polycondensation process of monomeric reactants / precursors

[0321] In a 200 ml glass reaction vessel equipped with a two-blade PET impeller stirrer powered by a mechanical stirrer at 400 rpm, 1,12-dodecanoic acid (3.3 g), 1,12-dodecanoic acid (2.9 g), and hexadecane (0.18 g), along with fragrance (2 g; ROC Green Woody from Robertet) and / or other oils, were placed and heated to 95 °C to produce an oil phase. Deionized water (90 g, aqueous phase) was added to the oil phase, and the reaction vessel was heated to 95 °C for 2 hours with stirring. Dodecylbenzenesulfonic acid (0.17 g) and deionized water (4.9 g) were then weighed into a 20 ml plastic beaker and stirred until homogeneous. This solution was then added to the reactor. The reactants were stirred at 95 °C for another 3 hours. The reactor was removed from the hot plate and stirring continued until room temperature was reached. (Sample number: 151-45-1, used for biodegradation testing when fragrance was removed).

[0322] A series of other embodiments using diols and / or diacids were also completed, and variations in reaction conditions, such as shorter stirring times, and the use of homogenizers (IKA (16000 rpm) or Silverson (4000 rpm, several minutes) instead of mechanical stirrers, were also investigated.

[0323] The fragrance is shown to be encapsulated, and the capsules, typically in the 1-25 micrometer range, are examined under an optical microscope. The capsules exhibit the characteristic of releasing the cargo when pressure is applied. In some cases, some cargo is encapsulated more securely (as shown in the table below, often after washing the capsules with hexane solvent to remove free or loosely bound fragrance).

[0324] Table 6: Fragrance loadings from fine emulsion polymerization of diacids and diols

[0325]

[0326] Branched or cross-linked structures can be generated using polyfunctional acids and / or polyfunctional polyols. In some cases, emulsion stability and reaction rate can be improved by replacing dodecylbenzenesulfonic acid, which acts as both a catalyst and a surfactant, with additives specifically optimized to meet each role, such as Fast Cat 4100 or p-TSA and alternative surfactants.

[0327] For example, in a 200 ml glass reaction vessel equipped with a two-blade PET impeller stirrer powered by a mechanical stirrer at 400 rpm, 1,12-dodecanoic acid (3.3 g, 144 mmol), castor oil (a lipophilic triol) (8.96 g, 96 mmol), and hexadecane (0.18 g), along with fragrance (2 g; ROC Green Woody from Robertet) and / or other oils, were placed and heated to 95 °C to produce an oil phase. Deionized water (90 g, aqueous phase) was added to the oil phase, and the reaction vessel was further heated to 95 °C and stirred for 2 hours. Dodecylbenzenesulfonic acid (0.17 g) and deionized water (4.9 g) were then weighed into a 20 ml plastic beaker and stirred until homogeneous. This solution was then added to the reactor. The reactants were stirred at 95 °C for another 3 hours. The reactor was removed from the hot plate and stirring continued until room temperature was reached. This resulted in the formation of slurry-like microcapsules containing the fragrance.

[0328] The solids content of the reaction mixture can be increased to obtain even higher fragrance loadings. For example, in a 200 ml glass reaction vessel equipped with a two-blade PET impeller stirrer powered by a mechanical stirrer at 400 rpm, 1,12-dodecanoic acid (3.3 g, 144 mmol), castor oil (8.96 g, 96 mmol), and hexadecane (0.18 g) along with fragrance (30 g; ROC Green Woody from Robertet) and / or other oils are heated to 95 °C to produce an oil phase. Deionized water (60 g, aqueous phase) is added to the oil phase, and the reaction vessel is heated to 95 °C for 2 hours with stirring. Dodecylbenzenesulfonic acid (0.17 g) and deionized water (4.9 g) are then weighed into a 20 ml plastic beaker and stirred until homogeneous. This solution is then added to the reactor. The reactants are stirred at 95 °C for another 3 hours. The reactor is removed from the hot plate and stirring continues until room temperature is reached. It forms a paste-like microcapsule containing fragrance.

[0329] Example 16: Biodegradation test of polymer shell prepared by in-situ microemulsion polycondensation

[0330] Similar blank polyester particles (e.g., our REF 151-45-1 and other compositions in Table 5) were synthesized as described above (Example 12), but without the addition of fragrance to prepare equivalent particles without cargo (which could impair or complicate biodegradability testing) for use in biodegradability testing. For example, under OECD 306 test conditions (in seawater, one of the least corrosive aquatic media options for biodegradability testing), a polymeric sample based on dodecanoic acid-dodecanool (C12 diacid-C12 diol) was measured to degrade by 21% after 28 days, indicating that it could be classified as inherently biodegradable. This specific sample is one of the more hydrophobic samples among the examples prepared (note that sodium benzoate was used as a reference under this test standard and measured 70% biodegradation after 28 days). Higher levels of degradation may be achieved using longer times and / or different OECD test methods (such as OECD 302 or 301) in other aquatic media such as activated sludge. Similarly, for fabricated polyester shell structures with lower hydrophobicity, a higher percentage of biodegradability can be reasonably expected. As previously mentioned, seawater testing (such as OECD 306 as described herein) is generally considered a mild medium for biodegradability testing, and is certainly less aggressive than other media mentioned in those other tests (activated sludge; surface water) for biodegradability testing.

[0331] 4. Crosslinked polyβ-amino esters and / or polyβ-thioesters via in-situ oil-in-water addition polymerization.

[0332] These embodiments of the invention demonstrate microcapsules having a lipophilic core and a biodegradable polymer shell by: (a) preparing an oil-in-water emulsion comprising an oil phase, cargo, and optionally added diluents or solvents and / or heating aids, and an aqueous phase comprising all donor and acceptor reactants, the oil phase comprising a stabilizer or emulsifier; (b) optionally adding a catalyst to one phase; (c) forming a polymer capsule wall by in-situ oil-in-water addition polymerization of the donor and acceptor reactants; and (d) obtaining cargo encapsulated in a polymer microcapsule shell.

[0333] The diluent will preferably be a water-miscible liquid at room temperature or readily meltable at moderate temperatures such as below 90°C or below 50°C, and may be a hydrocarbon oil, alkanes, molten wax, ester oil, fatty acid ester, aliphatic ester, or hydrocarbon carbonate ester. Some specific examples include mineral oils, long-chain alkanes such as hexadecane, aliphatic esters such as long-chain esters such as caprylate, myristate, oleate, cocoate, palmitate, or stearate, including isopropyl myristate as an example, or long-chain esters of short-chain acids or other mono- or poly-esters.

[0334] The catalyst is preferably a base added to the oil phase, such as triethylamine or another tertiary amine.

[0335] Example 17 Ref 210-26-1: Michael addition polymerization - using penta- / hexaacrylate (1 eq) and tetrathiol (0.9 eq), and also diamine TMPP (0.1 eq) (the ratios shown are the molar amounts of reactive groups acrylate; -SH; -NH, respectively). equivalent)

[0336] Add 0.61 g (3 mmol) of 4,4'-trimethylenedipiperidine (TMPP) and 6.28 g (13 mmol) of pentaerythritol tetra(3-mercaptopropionate) (PTTKMP, tetrathiol) to a glass jar containing 0.36 g (3.6 mmol) of triethylamine. Add a magnetic stir bar and 53 g of fragrance R1439-13 Sunburst Fresh (Robertet, FR) to the jar. Stir the mixture until both monomers are dissolved. Add 11 g of propylene glycol didecanoate / decanoate (Waglinol 2 / 7680) to the mixture to form the oil phase. In parallel, add 206 g of water, 32.8 g of a 10% w / w polyvinyl alcohol solution, and 0.2 g of Agitan 295 defoamer to the aqueous phase and stir at 150 rpm using a top-mounted stirrer. A syringe containing 5 g (10 mmol) of dipentaerythritol penta / hexaacrylate (DiPETA penta / hexaacrylate) was added to the oil phase and stirred for 30 seconds until the acrylate monomers were fully mixed. The oil phase was then rapidly added to the aqueous phase and stirred for 5 minutes to form a crude emulsion. This emulsion was homogenized with IKA Magic LAB at 4000 rpm and loaded into a 1 L resin reaction vessel equipped with an anchor stirrer. The reaction mixture was stirred at 150 rpm and 35°C for 24 hours to obtain a solid microcapsule slurry containing approximately 17 wt% (in the entire slurry) of fragrance.

[0337] Example 18 Ref210-86-1: Michael addition polymerization - using triacrylate (1.0) and tetrathiol (0.9) Encapsulation with cyclic secondary diamine TMPP (0.1)

[0338] Add 0.58 g (2.7 mmol) of 4,4'-trimethylenedipiperidine and 6.00 g (12.3 mmol) of pentaerythritol tetra(3-mercaptopropionate) (tetrathiol) to a glass jar containing 0.36 g (3.6 mmol) of triethylamine. Add a magnetic stir bar and 53 g of fragrance R1439-13 Sunburst Fresh (Robertet, FR) to the jar. Stir the mixture until both monomers are dissolved. Add 11 g of propylene glycol didecanoate / monodecanoate (Waglinol 2 / 7680) to the mixture to form the oil phase. In parallel, add 206 g of water, 32.8 g of a 10% w / w polyvinyl alcohol solution, and 0.2 g of Agitan 295 defoamer to the aqueous phase and stir at 150 rpm using a top-mounted stirrer. 5.43 g (18.2 mmol) of pentaerythritol triacrylate was loaded into a syringe and added to the oil phase. The mixture was stirred for 30 seconds until the acrylate monomers were fully incorporated. The oil phase was then rapidly added to the aqueous phase and stirred for 5 minutes to form a crude emulsion. This emulsion was homogenized with IKA Magic LAB at 4000 rpm and loaded into a 1 L resin tank equipped with an anchor stirrer. The reaction mixture was stirred at 150 rpm and 35 °C for 24 hours to obtain a solid microcapsule slurry containing approximately 17 wt% (in the slurry) of fragrance.

[0339] The same general procedure described above can be used or repeated to successfully prepare microcapsules with fragrance as a core using other reactants listed below. Note here and in all the following examples (all ratios are molar equivalents of functional reactive groups (acrylates, NH, SH)).

[0340] 215-45-1: TMPTA (1.0, trimethylolpropane triacrylate)-TMPP (0.1)-PTHKMP hexathiol (0.9, pentaerythritol hexa(3-mercaptopropionate)).

[0341] 215-49-1: TMPTA (1.0, trimethylolpropane triacrylate) - PTHKMP hexathiol (1.0, pentaerythritol hexa(3-mercaptopropionate). (Only β-thioesters are used: amine-free).

[0342] 215-46-1: PETA-tris(1.0, pentaerythritol triacrylate)-TMPP(0.1)-PTHKMP hexathiol(0.9, pentaerythritol hexa(3-mercaptopropionate).

[0343] 215-50-1: PETA-tris(1.0, pentaerythritol triacrylate)-PTHKMP hexathiol(1.0, pentaerythritol hexa(3-mercaptopropionate). (β-thioester only: amine-free).

[0344] 215-55-1: DiPETA (1.0, dipentaerythritol triacrylate)-TMPP (0.1)-trithiol (0.9, trimethylolpropane tri(3-mercaptopropionate)).

[0345] 215-56-1: DiPETA (1.0, dipentaerythritol triacrylate)-trithiol (1.0, (trimethylolpropane tris(3-mercaptopropionate)). (β-thioester only: amine-free).

[0346] Example 19 Ref No: 210-91-1 - Michael addition polymerization - with triacrylate (1.0)-tetrathiol (0.9) and TMPP (0.1) encapsulated with free radical initiator (APS / TMEDA)

[0347] Add 0.58 g (2.7 mmol) of 4,4'-trimethylenedipiperidine (TMPP) and 6.00 g (12.3 mmol) of pentaerythritol tetra(3-mercaptopropionate) (tetrathiol) to a glass jar containing 0.36 g (3.6 mmol) of triethylamine. Add a magnetic stir bar and 53 g of fragrance R1439-13 Sunburst Fresh (Robertet, FR) to the jar. Stir the mixture until both monomers are dissolved. Add 11 g of propylene glycol didecanoate / decanoate (Waglinol 2 / 7680) to the mixture to form the oil phase. In parallel, add 206 g (11.44 mol) of water, 32.8 g of 10% w / w polyvinyl alcohol solution, and 0.2 g of Agitan 295 defoamer to the aqueous phase and stir at 150 rpm using a top-mounted stirrer. 5.43 g (18.2 mmol) of pentaerythritol triacrylate was loaded into a syringe and added to the oil phase. The mixture was stirred for 30 seconds until the acrylate monomers were fully incorporated. The oil phase was then rapidly added to the aqueous phase and stirred for 5 minutes to form a crude emulsion. The emulsion was homogenized with IKA Magic LAB at 4000 rpm and loaded into a 1 L resin tank equipped with an anchor stirrer. The reaction mixture was stirred at 150 rpm. 0.71 g (3.1 mmol) of ammonium persulfate (25% w / w aqueous solution) was added. The mixture was degassed with nitrogen for 30 minutes. While the mixture was under a nitrogen layer, a small amount of 0.5 g (4.3 mmol) of tetramethylethylenediamine (25% w / w aqueous solution) was added. The temperature was raised to 35 °C and the nitrogen layer was maintained for 6 hours. Afterward, the nitrogen layer was removed, and the reaction mixture was stirred at 35 °C for another 18 hours to obtain a solid microcapsule slurry containing approximately 17 wt% (based on slurry) of fragrance.

[0348] Example 20: 201-82-1 - Amine donor only with triacrylate (1.0) - TMPP (1.0) and no additional Encapsulation of Michael addition polymerization catalyst (autocatalyzed by amine)

[0349] Add 2.80 g (13.7 mmol) of 4,4'-trimethylenedipiperidine (TMPP) to a glass jar. Add a magnetic stir bar and 53 g of fragrance R1439-13 Sunburst Fresh (Robertet, FR) to the jar. Stir the mixture until both monomers are dissolved. Add 11 g of propylene glycol didecanoate / monodecanoate (Waglinol 2 / 7680) to the mixture to form the oil phase. In parallel, add 206 g (11.44 mol) of water, 32.8 g of 10% w / w polyvinyl alcohol solution, and 0.2 g of Agitan 295 defoamer to the aqueous phase and stir at 150 rpm using a top-mounted stirrer. Load a syringe with 2.64 g (8.9 mmol) of pentaerythritol triacrylate and add it to the oil phase, stirring for 30 seconds until the acrylate monomers are fully mixed. Quickly add the oil phase to the aqueous phase and stir for 5 minutes to form a crude emulsion. The emulsion was homogenized with IKA Magic LAB at 4000 rpm and loaded into a 1L resin tank equipped with an anchor stirrer. The reaction mixture was stirred at 150 rpm and 35°C for 24 hours to obtain a solid microcapsule slurry containing fragrance.

[0350] Variations of the method for manufacturing flavor capsules include: adding a small amount (0.5 wt% or less, preferably 0.2 wt% or 0.1 wt% or less) of reactive monomeric acrylates such as β-carboxyethyl acrylate or acrylic acid or hydroxyethyl methacrylate at the start of the reaction, at the partial completion of the reaction, or near the end of the reaction to capture any residual thiols and / or free radical initiators such as APS / TMEDA (at the start of the reaction or shortly after the start of the reaction, in the middle of the reaction, or near the end of the reaction) to remove any residual acrylates and / or thiols, or adding chitosan or other insoluble polymer powders.

[0351] Example 21: In-situ Michael addition polymerization - using polyester prepolymers with added reactive unsaturated groups Encapsulation (Ref 210-54-1)

[0352] The polymer with itaconic acid ester double bonds synthesized as described above was used as a component in this Michael addition polymerization-encapsulation route. The polymer in this example is polyester Ref 201-43-1SA(0.75) / IA(0.25) / 1,12DDD (succinic acid / itaconic acid and 1,12-dodecanediol), pre-prepared using FASCAT 4100 as the catalyst for the polyester formation reaction (160°C / 24 hours). A reaction flask was prepared in a water bath set to 35°C. A pre-prepared polyester prepolymer (0.83 g) containing itaconic acid esters, made from succinic acid (37.5 mol%), itaconic acid (12.5 mol%), and dodecanediol (50 mol%), was dissolved in 53 g of fragrance (R1439-13, Woody Green) in a 150 mL beaker while stirring. A polyfunctional acrylate (DiPEHA, dipentaerythritol penta / hexaacrylate, 3.90 g) was added. The reaction mixture contained water (206 g), Agtan 295 (0.2 g), and polyvinyl alcohol (Poval). Prepare the aqueous phase (external phase) in parallel in another beaker (500 ml) containing 40-88 g of 32.8 g of 10% solution.

[0353] In another beaker, a mixture of thiol (PTHKMP, pentaerythritol hexa(3-mercaptopropionate) (7.17 g), catalyst (triethylamine, 0.36 g) and diluent oil (Waginol, 11.0 g) was prepared and added to the acrylate-polymer. The mixture was stirred for about 30 seconds to form an internal phase in which all reactants were present.

[0354] Then, immediately after adding the thiol mixture, the aqueous phase (external phase) was added, and the entire (two-phase) mixture was homogenized at 4000 rpm (using an IKA homogenizer). The mixture was then immediately transferred to a reaction flask and reacted at 35°C with stirring for approximately 24 hours. This produced a microcapsule slurry containing approximately 17 wt% fragrance (total slurry).

[0355] Example 22: Pre-reaction of amine donor in Michael addition polymerization-encapsulation

[0356] In some cases, it has been found that amines can be incorporated more stably or more easily into the shell of hybrid poly-β-amino ester-co-β-thioester polymers by, as a first step, reacting the amine groups with the acceptor molecules or capping the amine groups with the acceptor molecules, either in bulk or in the presence of added fragrance and / or diluent carriers, and optionally with the aid of heating. This is particularly useful where the amines are more soluble in water and therefore less suitable for in-situ oil-in-water polymerization, where all reactants are in the oil phase. This pre-capping of the amine donor results in a substantial or almost complete conversion of the NH groups to prepare adducts or oligomeric derivatives, prepolymers of the amine with polyfunctional acrylates or other acceptors, so that all or most of the amines now carry acrylate bonds (previously NH bonds), making them more lipophilic or less hydrophilic than the starting amines themselves. Such adducts, or initial prepolymers, or oligomers, remain as relatively low molecular weight adducts and may remain soluble in the cargo and / or added diluents and / or added excess acrylates, optionally with the aid of heating, or may otherwise dissolve readily. (Note: This is also the source of the prepolymers for Route 1 described above, which can be produced using the same general procedures to manufacture poly-β-amino ester or poly-β-thioester prepolymers (or copolymers thereof) for use in other routes using prepolymers as described. They may carry acrylates (reactive unsaturated groups) for prepolymer routes. The encapsulation stage of this pre-reactive route variant proceeds with homogenization / dispersion, and more donors (thiol donors) are added in stoichiometric amounts (or approximately so) based on the available acrylate groups remaining after amine donor end-capping.)

[0357] Example 22A: Microcapsules Ref 215-32 (molar equivalent ratio: PTHKMP (0.8) / TMPP (0.2) / PETA) (tetra;(1.0)))-sequential reaction.

[0358] The bifunctional amine donor TMPP (1.18 g) was dissolved in approximately half of the fragrance (Green Woody). The polyfunctional acrylate pentaerythritol tetraacrylate (4.94 g) was added, and the mixture was stirred in a beaker for 2 hours to essentially cap the amine NH with the acrylate. In parallel, the external (aqueous) phase was prepared, comprising (in a 500 ml beaker): water (205.9 g), Poval 40-88 (32.81 g 10% solution), and Agtan 295 (0.20 g). The remainder of the internal (oil) phase was premixed in another beaker: (hexathiol, pentaerythritol hexa(3-mercaptopropionate) PTHKMP, 5.85 g), Waglinol (10.68 g), the remaining fragrance (making the total fragrance used 54.32 g), and triethylamine (0.36 g) as a catalyst. Then mix it with the acrylate-TMPP fragrance mixture (for about 30 seconds) to prepare the complete oil phase.

[0359] The oil phase was added to the aqueous phase in a 500 ml beaker and stirred for about 1 minute. The mixture was then homogenized using an IKA homogenizer at 4000 rpm for about 1 minute. The mixture was then transferred to a reaction flask and reacted with stirring for 24 hours to form a microcapsule slurry containing fragrance.

[0360] Example 22B: Microcapsules Ref 215-33: PTHKMP (0.9) / TMPP (0.1) / PETA (tetra) (1.0) - sequence Pervasion reaction.

[0361] Using the same procedure as described above (Example 22A), and compared to 215-32 above, reacting with half (the molar equivalent) of TMPP, a microcapsule slurry containing fragrance was produced (Ref 215-33). Details are as follows: Internal phase: PETA tetraacrylate (5.06 g), TMPP (2.41 g) – pre-reacted in half of the fragrance as described above; PTHKMP (4.49 g), R1439-13 GreenWoody (53.42 g), Waglinol (10.68 g), and triethylamine (0.36 g). External phase: Water (205.90 g), Poval 40-88 (10% sol; 32.81 g), Agtan 295 (0.20 g).

[0362] Using the following reactants and following the same procedure as described above, other embodiments were carried out, and flavor-core microcapsules were successfully prepared.

[0363] 215-47-1: TMPTA (1.0, trimethylolpropane triacrylate)-TMPP (0.1)-PTHKMP hexathiol (0.9, pentaerythritol hexa(3-mercaptopropionate)).

[0364] 215-48-1: PETA-tris(1.0, pentaerythritol triacrylate)-TMPP(0.1)-PTHKMP hexathiol(0.9, pentaerythritol hexa(3-mercaptopropionate).

[0365] 215-57-1: DiPETA (1.0, dipentaerythritol triacrylate)-TMPP (0.1)-trithiol (0.9, trimethylolpropane tri(3-mercaptopropionate)).

[0366] Example 22C: Another example of sequential pre-reaction of amine or water-soluble donors before encapsulation with a second donor.

[0367] Using the same sequential pre-reaction procedure as in Example 22A, other microcapsules can be prepared via an in-situ polymerization-encapsulation route using water-soluble or sensitive donors.

[0368] Detailed information on microcapsules Ref 215-41: Internal phase: DiPETA penta / hexaacrylate: 5.40 g; HMDA: 0.33 g (pre-reacted); PTTKMP: 6.23 g; R1439-13 Green Woody: 53.42 g; Waglinol: 10.68 g; Triethylamine: 0.36 g. External phase: Water (205.90 g); Poval 40-88 (10% sol; 32.81 g), Agtan 295 (0.20 g).

[0369] Example 22D For other diamines such as isophorone diamine (IPDA), dodecanediamine, and hexamethylenediamine (HMDA), the same procedure as described above is followed: pre-reacting the amine donor with the acrylate acceptor, and then reacting the thiol donor in oil using a polyfunctional thiol in an oil-in-water emulsion polymerization. These other diamines demonstrate the breadth of this method (some are particularly water-soluble primary diamines that only become less water-soluble or insoluble by the pre-reaction stage) and are used stoichiometrically (total donor H to total acceptor groups ratio of approximately 1:1), targeting a reactive functionality (f) of 4 (NH), and in other examples, also targeting a reactive functionality (f) of 2 (NH). Therefore, a lower acceptor level (slightly excess donor) may result in some residual NH in the polymer shell formed later at a (f2) ratio. The thiol used in these examples is hexathiol, and the acrylate is tetraacrylate. All combinations were encapsulated with approximately 17 wt% of flavoring (in the slurry), and the release of flavoring could be observed when crushed under a microscope slide.

[0370] Table 7: Other Examples of Amine-Thiol Compositions for Microencapsulation via Pre-reaction with Amine Donors

[0371]

[0372] Remark:

[0373] PTTKMP: Pentaerythritol tetra(3-mercaptopropionate)

[0374] PTHKMP: Pentaerythritol hexa(3-mercaptopropionate)

[0375] IPDA: Isophorone diamine

[0376] HMDA: Hexamethylenediamine

[0377] DDDA: 1,12-Dodecanediamine

[0378] DiPETA: Dipentaerythritol Triacrylate (Hexa / Phnomegaly)

[0379] PETA tetra: Pentaerythritol tetraacrylate

[0380] Example 22E

[0381] Microcapsules with a 10 mol% excess of acrylate functional groups (10 mol eq% excess) were also prepared using the method described in Example 22 above. Microcapsules that could significantly release fragrance upon crushing (fragrance accounted for 17% by weight of the total slurry) were successfully prepared. The capsules (Ref 210-62-1) were prepared by pre-reacting a bifunctional secondary amine TMPP (0.1 mol eq) with a tetrafunctional acrylate (pentaerythritol tetraacrylate (PETA-tetra, 1.1 mol eq), followed by mixing with a hexafunctional thiol (dipentaerythritol hexa(3-mercaptopropionate) (DiPTHKMP, 0.9 mol eq) and homogenizing with an aqueous phase, followed by in-situ oil-in-water emulsion polymerization to form the capsule shell.

[0382] Example 22F

[0383] The method described in Example 22 above is also applicable to the preparation of microcapsules without an additional catalyst but using an amine donor as a self-catalyst. Microcapsules (17% by weight of fragrance in the entire slurry) were successfully prepared, and the fragrance was significantly released upon crushing. The capsules (Ref 210-61-1) were prepared by pre-reacting a bifunctional secondary amine TMPP (0.1 mol eq) with a tetrafunctional acrylate (pentaerythritol tetraacrylate; PETA-tetra, 1.0 mol eq), followed by mixing with a hexafunctional thiol (dipentaerythritol hexa(3-mercaptopropionate) (DiPTHKMP), 0.9 mol eq) and homogenizing with an aqueous phase, followed by in-situ oil-in-water emulsion polymerization to form the capsule shell.

[0384] Example 22G

[0385] The method described in Example 22 above is also applicable to the preparation of microcapsules without the use of additional additives in the process. An additional fragrance (approximately 11 g) was used instead of Waglinol in Example 22 above. Microcapsules (fragrance comprising 20% ​​by weight of the total slurry) were successfully prepared, and the fragrance was significantly released upon crushing. Capsules (Ref 210-63-1) were prepared by pre-reacting a bifunctional secondary amine TMPP (0.1 mol eq) with a tetrafunctional acrylate (pentaerythritol tetraacrylate; PETA-tetra, 1.0 mol eq), followed by mixing with a hexafunctional thiol (dipentaerythritol hexa(3-mercaptopropionate) (DiPTHKMP), 0.9 mol eq) and homogenizing with an aqueous phase, followed by in-situ oil-in-water emulsion polymerization to form the capsule shell.

[0386] Example 23: Other embodiments of Michael in-situ addition polymerization - encapsulation process - using tetrafunctional or more Highly functional donors and recipients

[0387] Various samples were prepared using the same procedure as described above, including various combinations of tetrafunctional or hexafunctional thiols (with or without TMPP as an additional donor) and tetrafunctional or penta / hexaacrylates. See the table below. All microcapsules prepared according to the above method successfully shipped with fragrance, and all formed capsules contained approximately 17 wt% fragrance (approximately 90-100% encapsulation efficiency). All exhibited fragrance release upon crushing and also showed fragrance retention upon formulation into representative fabric conditioning formulations (pH 3). Please refer to the example data below.

[0388] The equivalence weights are largely matched such that the total stoichiometry of the donor (thiol with or without TMPP or other amines) is approximately equal to the total stoichiometry of the acceptor (acrylate in these examples). In the presence of added TMPP, it is preferably present at about 10 or 20 eq. mol%. The remaining donor is a polyfunctional thiol, more preferably 10 mol% (the mol% of the thiol is subsequently adjusted to ensure that the overall stoichiometry of the donor and acceptor is matched (so the moles of NH and SH groups combined) equals the moles of the given acrylate groups).

[0389] After aging at 40°C for 14 days at pH 3, 7, and 11, the capsules were stable "as is" and "as is" in their slurry. Some were stable when tested at 40°C, neutral, while others were stable at pH far from neutral (the capsules remained remarkably "intact" and showed release upon crushing). It was noted that some capsules with higher water-soluble or sensitive amine equivalents (over approximately 20 mol% based on donor equivalent groups) were softer or had poorer retention when used with the aggressive plasticized flavorings used herein, but such capsules are expected to successfully retain other lipophilic goods, exhibiting faster biodegradation profiles compared to similar low-amine-content capsules.

[0390] Table 8: Summary of some exemplary flavor microcapsules, some of which are flavor contents tested by the sensory panel (see Table 8). Down (Further results examples)

[0391]

[0392]

[0393] Remark:

[0394] Tetrathiol = Pentaerythritol tetra(3-mercaptopropionate) (PTTKMP)

[0395] Hexathiol = Pentaerythritol hexa(3-mercaptopropionate) (PTHKMP)

[0396] Penta / hexa acrylate = Dipentaerythritol penta / hexa acrylate (DiPEHA)

[0397] Tetraacrylate = Pentaerythritol tetraacrylate

[0398] Triacrylate = Pentaerythritol triacrylate

[0399] TMPP = 4,4'-Trimethylenedipiperidine

[0400] TMPTA = Trimethylolpropane triacrylate

[0401] Example 24: Comparative Example of the Prior Art (Ref 201-60-1) - Using Interfacial Polymerization and Water-Soluble Dithiols as Sole donor.

[0402] An embodiment from the publication Liao et al., “Fragrance-containing microcapsules-based interfacial thiol-ene polymerization” (J. Appl. Polym. Sci. 2016, doi:10.1002 / App.43905), was completed (reproduced) using pentaerythritol tetraacrylate and a prescribed water-soluble dithiol, namely dithiothreitol, via a significantly excessive addition in the aqueous phase, according to the published procedure. While capsules with the fragrance (Green Woody) used herein were formed, they were very soft and unstable, appearing to be plasticized by the fragrance used, and the product slurry had a very pronounced and unpleasant thiol odor that masked the presence of any fragrance. These points were raised earlier in the prior art discussion and showed that the use of an excessive amount of the water-soluble dithiol donor during interfacial polymerization did not result in a useful fragrance-retaining capsule.

[0403] For prior art reference examples using classical interfacial polymerization and a molar excess of water-soluble dithiol, trimethylolpropane triacrylate (TMPTA; sample A1 in this paper) is used because it is described as an optimal combination of high efficiency and stability. The amount used is:

[0404] Oil phase: TMPTA (0.2615g; A1); R14-3913 Flavoring (15g);

[0405] Aqueous phase: Mowiol 40-88 (2%; 45g); and

[0406] Feed mixture(Soluble in water): Dithiothreitol (0.5885g; D1); K2CO3 (0.04g); Water (12g).

[0407] The aqueous phase, oil phase, and feed phase were prepared separately. The oil and aqueous phases were homogenized (using an Ultra-Turrax 25 at 10,000 rpm for 3 minutes). The homogenized emulsion was transferred to a reactor and stirred. The feed mixture was added dropwise while stirring. The reaction mixture was stirred for 3 hours. A slurry of microcapsules was formed. A very strong, unpleasant thiol odor was observed, and the capsules softened upon standing.

[0408] Example 25: Spray-dried microcapsules containing fragrance were prepared by Michael addition polymerization-encapsulation (Ref: 210-36-1；210-48-1)

[0409] Microcapsules (210-36-1) containing approximately 17% Green Wood fragrance were prepared using a similar method with penta / hexaacrylate (1 mol eq), tetrathiol (0.9 mol eq), and TMPP (0.1 mol eq; pre-reacted). Details are as follows:

[0410] Internal phase: All reactants: DiPEHA (penta / hexaacrylate) (functionality 5.5; 5.29 g); 4'-trimethylenedipiperidine (TMPP, functionality 2, 0.58 g) and pentaerythritol tetra(3-mercaptopropionate) (PTTKMP, functionality 4, 6.10 g), as well as R1439-13 GreenWoody; Waglinol (53 g) and triethylamine (catalyst; 0.36 g).

[0411] External phases: water (206 g), Poval 40-88 (10% sol, 32.8 g), Agitan 295 (0.2 g).

[0412] Mix the aqueous phase components: stir water and Poval; add Agtan. Mix the oil phase components in two beakers: in beaker 1, mix DiPEHA, TMPP + 23g fragrance. In beaker 2, mix PTTKMP, TEA, and Waglinol / fragrance. Stir both beakers for 1 hour. Add the mixture from beaker 1 to beaker 2 and stir for 30 seconds. Then add the aqueous phase and homogenize (Ika) the mixture at 4000 rpm for 5 minutes. Add xanthan gum (0.1% of the total slurry volume), transfer the mixture to a reaction flask, and react at 35°C with stirring for 24 hours.

[0413] Spray drying method - for 210-48-1(Using a Buchi B290 spray dryer): Dilute 277g of slurry (25% solids) to 5% solids with 1385g of deionized water, add 8.31g (3% of 210-36-1 slurry) of Sipernat 50S silica and mix thoroughly with a top-mounted stirrer for 30 minutes. Then, load the sample over time to produce spray-dried sample 210-48-1. Conditions: Inlet temperature: 190°C; air flow rate: 4cm (10L / min); calibration setting: 18.

[0414] The separated, free-flowing, dry capsules can be stably redispersed in water and formulated into representative fabric conditioning systems, exhibiting either release or fragrance release during testing.

[0415] Example 26: Microcapsules containing peppermint oil (Ref 210-53-1)

[0416] The microcapsules produced by this invention can contain a variety of lipophilic or oil-soluble cargoes. The existing successful encapsulation of dichloromethane, a solvent that is substantially immiscible with water (used for biodegradation test samples), demonstrates this versatility. Fragrances are used in most instances because they are considered to aggressively plasticize the cargo, making it difficult to encapsulate and retain it. Another example of an oil-based cargo is described here, using a procedure similar to that described above.

[0417] Prepare a sealed reactor flask in a water bath at 35°C.

[0418] Dissolve 0.58 g of TMPP in 33 g of peppermint oil in a 250 ml beaker. Once dissolved, add the remaining oil (internal) phase (6.50 g of PTHKMP hexathiol; 11 g of Waglinol; 0.36 g of triethylamine) to the 250 ml beaker (excluding acrylate and 20 g of flavoring).

[0419] In another 100 ml beaker, PETA tetraacrylate (4.88 g, pentaerythritol tetraacrylate) was mixed with 20 g of peppermint oil. The external (aqueous) phase (206 g water, 32.8 g Poval (10%), 0.2 g Agitan 295) was prepared in parallel in a 500 ml beaker equipped with a top stirrer.

[0420] The acrylate-oil mixture was added to another portion of the inner phase and mixed for 30 seconds. Then, all the mixed inner (oil) phase was added to the outer aqueous phase and mixed for 1 minute, homogenized at 4000 rpm using an Ika mixer (homogenization), and then transferred to a prepared reaction flask. The reaction was carried out in the flask at 35°C for 24 hours. Microcapsules containing peppermint oil were prepared in the slurry (17 wt%–100% efficiency).

[0421] Example 26A: Microcapsules containing shea butter (Ref 215-62-1)

[0422] Shea butter was encapsulated again using TMPP (0.1 mol eq functional groups), PTKHP (0.9 mol eq), and PETA tetraacrylate (1.0 mol eq) in a method similar to that in Example 26. Spherical microcapsules containing shea butter were formed. The shea butter was significantly released upon crushing.

[0423] Example 27: Use of bifunctional acrylate BDDA (1.0 mol) in in-situ Michael addition microencapsulation process The aroma-containing functional groups), TMPP (0.1 mol eq), and pentaerythritol hexa(3-mercaptopropionate) (PTHKMP, 0.9 mol eq) Microcapsules of Sunburst Fresh R14-3913 (Ref 210-66-1)

[0424] The aqueous phase was prepared by mixing 32.8 g of a 10% polyvinyl alcohol aqueous solution and 206 g of deionized water. 0.2 g of defoamer was also added.

[0425] The oil phase was prepared by dissolving 0.58 g of 4,4-trimethylenedipiperidine in 54 g of Fragrance Sunburst fresh. 11 g of propylene glycol dioctanoate / decanoate was added, followed by 0.36 g of triethylamine and 6.19 g of pentaerythritol hexa(3-mercaptopropionate). 5.22 g of butanediol diacrylate was mixed into the oil phase. The oil phase was added to the aqueous phase under mechanical stirring to form a crude emulsion. The crude emulsion was homogenized using an IKA magnetic laboratory homogenizer at 4000 rpm once. The formed emulsion was transferred to a reaction vessel and heated to 35°C. The oil-in-water emulsion was then allowed to react for 24 hours to complete polymerization. The resulting microcapsule slurry was an aqueous slurry of microcapsules visible under an optical microscope, such as… Figure 12 As shown.

[0426] Example 28: Preparation of a compound containing butanediol diacrylate, 4,4-trimethylenedipiperidine and pentaerythritol hexadecylene A polymer shell of (3-mercaptopropionate) encapsulates microcapsules containing the home care fragrance Sunburst Fresh R14-3913. (Ref215-42-1)

[0427] The aqueous phase was prepared by mixing 32.8 g of a 10% polyvinyl alcohol aqueous solution and 206 g of deionized water. 0.2 g of defoamer was also added. An acrylate / amine prepolymer was prepared by dissolving 0.17 g of trimethylenedipiperidine (TMPP) and 5.06 g of pentaerythritol tetraacrylate in 33.4 g of Fragrance Sunburst Fresh. The oil phase was prepared by dissolving 6.7 g of pentaerythritol hexa(3-mercaptopropionate) in 20 g of Fragrance Sunburst Fresh. 10.7 g of propylene glycol dioctanoate / decanoate was added, followed by 0.36 g of triethylamine. The oil phase was added to the prepolymer under mechanical stirring to form the internal phase. The internal phase was added to the aqueous phase under mechanical stirring to form a crude emulsion. The crude emulsion was homogenized using an IKA magnetic laboratory homogenizer at 4000 rpm once. The formed emulsion was transferred to a reaction vessel and heated to 35°C. The oil-in-water emulsion was then allowed to react for 24 hours to complete the polymerization. The resulting microcapsule slurry was an aqueous slurry of microcapsules visible under an optical microscope, such as... Figure 12 As shown.

[0428] Example 29: Coated / Multi-layered Capsules

[0429] Samples of the capsules of the present invention (samples 215-09-1, 215-15-1, and 215-16-1) (freshly prepared slurries thereof) were filtered and encapsulated in a second coating of cross-linked sodium alginate. The filtered capsules were dispersed in a buffered aqueous solution of sodium alginate. The mixture was slowly added (via a feeding funnel or syringe) to a stirred calcium chloride solution under stirring. Larger capsules (“visible beads”) were formed, consisting of the microcapsules of the present invention surrounding or embedded in a cross-linked alginate coating or capping layer.

[0430] Example 30: Samples used for biodegradation testing (Michael addition polymerization)

[0431] Alternatively, for testing purposes, dichloromethane can be used as another lipophilic cargo to prepare an equivalent composition (similar shell material) of the above microcapsules, without fragrance, and then evaporated to leave only the polymer shell material for biodegradation testing.

[0432] Example 31: (213-05-1 / 213-06-1: Encapsulation for biodegradation testing of polymer shell materials) DCM solvent (subsequently removed by evaporation); penta / hexaacrylate (1.0); tetrathiol (0.9)-TMPP (0.1)

[0433] Add 0.24 g (1.2 mmol) of 4,4'-trimethylenedipiperidine (TMPP) and 2.50 g (5.1 mmol) of pentaerythritol tetra(3-mercaptopropionate, PTKMP) to a glass jar containing 0.14 g (1.2 mmol) of triethylamine. Add a magnetic stir bar and 25.6 g of dichloromethane to the jar. In parallel, add 206 g (11.44 mol) of water, 32.8 g of a 10% w / w polyvinyl alcohol solution, and 0.2 g of Agitan 295 defoamer to the aqueous phase and stir at 150 rpm using a top-mounted stirrer. Add 2 g (3.8 mmol) of dipentaerythritol penta / hexaacrylate (DiPEHA) to the oil phase using a syringe and stir for 30 seconds until the acrylate monomers are fully mixed. Quickly add the oil phase to the aqueous phase and stir for 5 minutes to form a crude emulsion. The emulsion was homogenized at 4000 rpm using an IKA magnetic laboratory homogenizer and transferred to a 1 L resin tank equipped with an anchor stirrer and a connected condenser. The reaction mixture was stirred at 150 rpm and 35°C for 24 hours. Subsequently, the mixture was transferred to a beaker with a magnetic stir bar and stirred in a fume hood for 72 hours to evaporate the dichloromethane. No solvent was detected by GC afterward. The biodegradability of the dispersion was assessed using activated sludge inoculum via 301F.

[0434] The sample, which was subsequently evaporated from the dichloromethane cargo (prepared from penta / hexaacrylate and tetrathiol), was similar to 210-26-1 (an equivalent shell prepared as described above with fragrance, which exhibits fragrance release / release after formulation into a representative fabric conditioning system). In OECD 301F testing using activated sludge from a local water treatment plant (Yorkshire Water), the biodegradation rate was 21% after 28 days and 47% after 60 days.

[0435] Other samples for biodegradation testing (OECD 301F protocol; activated sludge) were prepared using the same method as those prepared with dichloromethane (DCM) as cargo and subsequently evaporated to leave only the residual shell material. Their compositions are summarized in the table below (Table 9), with exemplary figures as shown. Figure 17 As shown.

[0436] Example 32: Sensory and other fragrance release tests

[0437] The following summarizes the fragrance release (triggered by sensory panel testing via friction) observed in the formulation of fragrance-infused microcapsules prepared by in-situ oil-in-water Michael addition polymerization into a fabric conditioning base. Examples of similar shell-wall preparations (DCM method) used for OECD 301F biodegradability testing are also summarized and evidence of biodegradability is presented here.

[0438] Table 9: Examples of microcapsules prepared via in-situ oil-in-water Michael addition polymerization-encapsulation, including those for biological applications. Similar samples from degradation tests

[0439]

[0440]

[0441] Remark:

[0442] Tetrathiol = Pentaerythritol tetra(3-mercaptopropionate) (PTTKMP)

[0443] Hexathiol = Pentaerythritol hexa(3-mercaptopropionate) (PTHKMP)

[0444] Penta / hexa acrylate = Dipentaerythritol penta / hexa acrylate (DiPEHA)

[0445] Tetraacrylate = Pentaerythritol tetraacrylate

[0446] Triacrylate = Pentaerythritol triacrylate

[0447] TMPP = 4,4'-Trimethylenedipiperidine

[0448] TMPTA = Trimethylolpropane triacrylate

[0449] Test procedure for fragrance holding test samples (fabric conditioner basics):

[0450] The capsule slurry was tested in a blind sensory evaluation (fragrance bloom test) by a group of people (minimum 2, usually 3-5). Note: The microcapsules produced typically contain about 15-30 wt% fragrance (encapsulated in the slurry), with most recorded data showing about 17 wt%.

[0451] Typical pre-screening sensory test

[0452] The sizing agent was prepared using 18g of fabric conditioning / softening agent formulation and a certain amount of sizing agent. test A mixture was prepared by adding water to make a test mixture containing 0.1g of flavor (based on the amount of flavor encapsulated in the slurry).

[0453] parallellyTo prepare a fabric washing mixture, each test mixture was prepared in a 2-liter beaker using a top-mounted stirrer at 250 rpm. This consisted of 2 g of each of the above test mixtures and 998 g of water (tap water). Small cubes of towel material (approximately 75 mm x 75 mm; the number depends on the number of people testing the sizing sample) were added to the beaker and stirred for 5 minutes. The beakers were then removed and hung to air dry overnight, for a period of 16 hours.

[0454] The next day, another person (not the person who prepared the sample) smelled the untreated towel, then the pure fragrance sample, and labeled the intensity value of each with a reference point between 1 and 9 (9 = the highest fragrance intensity – usually pure fragrance). Prepared samples on towels were randomly selected and smelled, and the intensity value was recorded. The towel materials were then rubbed together for 5 seconds and smelled again. The intensity after rubbing was also recorded. This process was repeated randomly until each group member had tested all samples.

[0455] Calculate the average strength of each sample before (before friction) and after (after friction). Exemplary data are shown below.

[0456] Detailed sensory testing: In another testing method, the terg-o-tometer was used.

[0457] The prototype fabric softener / conditioner base formulations used for this type of testing include:

[0458]

[0459] The prototype fabric softener / conditioner has 10% pores to accommodate other ingredients added later. Phase B, containing 0.5% active pure fragrance or fragrance encapsulation, was prepared by premixing with an equal amount of emulsifier (such as Tomadol 1-73B) and then added to the fabric conditioner base phase A. The conditioner was then equilibrated with deionized water. Finally, if necessary, the pH of the prepared fabric conditioner base was adjusted to pH 2.5–3.5 with a weak acid. The Brookfield viscosity of the prepared base varied between 100–600 cP, depending on the fragrance encapsulation test material. All tested capsules were observed to be stable in the formulation.

[0460] Terg-o-tometer testing method

[0461] Water hardness: 200 ppm (Ca2+) 2+ / 1Mg 2+ Temperature: 100°F; Fabric conditioner: 2g / L

[0462] Test fabric: 12x12-inch pre-treated cotton towels, cut into 3x3-inch squares, 10 squares per 1L of detergent.

[0463] Rinse for 5 minutes, stirring at 100 rpm. After rinsing, squeeze out excess water; dry: air dry overnight.

[0464] Sensory panel evaluation: Panel members were asked to smell the reference sample first, and then rate the fragrance intensity of the sample (least strong = 1 and strongest = 9 / 10).

[0465] Afterwards, the team members randomly obtained a sample of the treated towel to rate the relative fragrance intensity before and after rubbing.

[0466] Below are examples of release data from the Fragrance Bloom Sensory Panel, presented after formulation of a representative liquid laundry fabric conditioner and application to fabrics (before and after rubbing). Figure 13-16 ).

[0467] Example 33: Sensory / Application Test

[0468] The fragrance release from two microcapsule samples prepared according to the above procedure was evaluated in various formulations. The two samples are:

[0469] 215-15-1; Tetraacrylate-PTHKMP hexathiol-TMPP (1:0.9:0.1): Capsules 24% solids (in water); Fragrance: 17wt% (in slurry)

[0470] 210-50-1; DiPETA penta / hexaacrylate-PTHKMP; hexahydride-TMPP-CEA (carboxyethyl acrylate) (1:0.9:0.1:0.1): Capsules 24% solids (in water); Fragrance: 17wt% (in slurry)

[0471] Example 33A: Fragrance encapsulant in combing cream formulation

[0472] Add the two types of capsules (codes 210-50-1 and 215-15-10) to the following formulation:

[0473]

[0474] Each capsule was administered at doses of 0.5% and 1% by weight, and the coded samples were blind-evaluated by three untrained panel members. Aroma was evaluated on 5g, 10-inch long, once-bleached Caucasian hair. 0.5g of each sample was weighed, applied to a dry section of hair, and gently massaged in for 20 seconds. The samples were allowed to stand for 15 minutes. Three untrained panel members were asked to perform a comparative test in pairs, answering the question, "Which of the two samples smells the best?" They were asked to evaluate the aroma before and after combing the hair three times with a fine-toothed comb. All samples containing the fragrance capsules were labeled "stronger odor" relative to the control after combing by all panel members. The capsules were observed to be stable in the formulation.

[0475] Example 34B: Fragrance encapsulation in styling gel formulations

[0476] Add the two types of capsules (codes 210-50-1 and 215-15-10) to the following formulation:

[0477]

[0478] Each capsule was administered at doses of 0.5% and 1% by weight, and the coded samples were blind-evaluated by three untrained panel members. Aroma was evaluated on 5g, 10-inch long, once-bleached Caucasian hair. 0.5g of each sample was weighed, applied to a dry hair strand, and gently massaged in for 20 seconds. The samples were allowed to stand for 15 minutes. Three untrained panel members were asked to perform a comparative test in pairs, answering the question, "Which of the two samples smells the best?" They were asked to evaluate the aroma before and after combing the hair three times with a fine-toothed comb. Before combing, all panel members agreed that all samples were very similar and had almost no odor. All samples containing the fragrance capsules were labeled "stronger odor" relative to the control after combing by all panel members. Both capsules showed a dose response. The capsules were observed to be stable in the formulation.

[0479] Example 34C: Fragrance encapsulation in heavy-duty cleaning agent formulations

[0480] Add the two types of capsules (codes 210-50-1 and 215-15-10) to the following formulation:

[0481]

[0482] Each capsule was administered at doses of 0.5% and 1% by weight, and the coded samples were blind-evaluated by three untrained panel members. Aroma assessment was performed on glass plates. 0.5 g of each sample was weighed and transferred to a glass surface. The sample was laid on the plate by tilting it to minimize mechanical manipulation. The samples were left to stand in a fume hood for 20 minutes until dry. Three untrained panel members were asked to perform a comparative test in pairs, answering the question, “Which of the two samples smells the best?” They were asked to evaluate the aroma before and after rubbing the samples three times with gloved fingers. All samples were rubbed by the same researcher. Before rubbing, all panel members agreed that all samples were very similar and had almost no odor. All panel members considered all samples containing fragrance capsules to be “more odorous” relative to the control after rubbing. The capsules were observed to be stable in the formulation.

[0483] Example 34D: Fragrance encapsulation in multipurpose cleaning agent formulations

[0484] Add the two types of capsules (codes 210-50-1 and 215-15-10) to the following formulation:

[0485]

[0486] Each capsule was administered at doses of 0.5% and 1% by weight, and the coded samples were blind-evaluated by three untrained panel members. Aroma assessment was performed on glass plates. 0.5 g of each sample was weighed and transferred to a glass surface. The sample was laid on the plate by tilting it to minimize mechanical manipulation. The samples were left to stand in a fume hood for 20 minutes until dry. Three untrained panel members were asked to perform a comparative test in pairs, answering the question, “Which of the two samples smells the best?” They were asked to evaluate the aroma before and after rubbing the samples three times with gloved fingers. All samples were rubbed by the same researcher. Before rubbing, all panel members agreed that all samples were very similar and had almost no odor. All panel members considered all samples containing fragrance capsules to be “more odorous” relative to the control after rubbing. The capsules were observed to be stable in the formulation.

[0487] While compositions and methods of the disclosed and / or claimed inventive concept have been described according to specific aspects, it will be apparent to those skilled in the art that variations may be made to the compositions and / or methods, as well as the steps or sequence of steps of the methods described herein, without departing from the concept, spirit, and scope of the disclosed and / or claimed inventive concept. All such similar substitutions and modifications that are apparent to those skilled in the art are considered to be within the spirit, scope, and concept of the disclosed and / or claimed inventive concept.

Claims

1. A microcapsule comprising: (i) a lipophilic core; and (ii) a polymeric microcapsule shell; wherein the microcapsule shell comprises branched or crosslinked polymers derived from an aliphatic polyester prepolymer selected from aliphatic polyesters comprising at least one reactive unsaturated functional group present at a chain end or distributed along the chain; wherein the reactive unsaturated functional group is selected from the group consisting of acrylate, methacrylate, itaconate, citraconate, maleate, fumarate, crotonate, and combinations thereof; wherein the aliphatic polyester is derived from at least one diacid selected from the group consisting of succinic acid, malonic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, and maleic acid, or at least one anhydride selected from the group consisting of succinic anhydride; and at least one diol selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, pentane diol, hexane diol, octane diol, decane diol, and dodecane diol; wherein the aliphatic polyester comprises a crystalline structure; wherein the microcapsule is storage stable and its polymeric shell is biodegradable, wherein the polymeric microcapsule shell is biodegradable in an aqueous medium or a solid medium, or is compostable; and wherein the aqueous medium or solid medium is selected from the group consisting of activated sludge, secondary treatment effluent, surface water, fresh water, seawater, soil, and compost.

2. The microcapsule of claim 1, wherein the lipophilic core is selected from the group consisting of an agrochemical, an antimicrobial, an antifouling agent, an antioxidant, a catalyst, a cosmetic active, a colorant, a detergent, an edible oil, an essential oil, a food additive, a flavorant, a fragrance, a halogenated compound, an insect repellent, a lipid, a lipophilic scale inhibitor, a mineral oil, an oral care active, an organic solvent, an organic ester, a perfume, a preservative, a UV absorber, a vegetable oil, and combinations thereof.

3. The microcapsule of claim 1, wherein the core is a fragrance, a perfume, or an essential oil.

4. The microcapsule of claim 1, wherein the microcapsule is used in a consumer care composition selected from the group consisting of household care and cleaning compositions.

5. The microcapsule of claim 1, wherein the microcapsule is used in a fabric conditioner composition or a laundry detergent composition.

6. The microcapsule of claim 1, wherein the polymeric microcapsule shell material exhibits a biodegradation rate of at least 20% in an aqueous medium when measured by OECD test methods 301, 302, or 306.

7. The microcapsule of claim 1 or 6, wherein the polymeric microcapsule shell material exhibits signs of biodegradation within 120 days.

8. The microcapsule of claim 1, wherein the microcapsule is stable as a core-shell capsule in an aqueous slurry, a water-based formulation, or a solvent-based formulation.

9. The microcapsule of claim 1, wherein the microcapsule is storage stable as a core-shell capsule in a solid formulation or a printed product.

10. The microcapsule of claim 8 or 9, wherein the formulation is selected from the group consisting of a laundry powder or tablet or liquid, and a cosmetic formulation.

11. The microcapsule of claim 8 or 9, wherein the formulation has a pH range of 3-11.

12. The microcapsule according to claim 1, wherein the microcapsule is part of a double-layer microcapsule, a multi-layer microcapsule or an outer-coated microcapsule.

13. The microcapsule according to claim 12, wherein the double-layer or multi-layer or outer-coated microcapsule further comprises a hydrogel.

14. The microcapsule according to claim 1, wherein the microcapsule has an average diameter of 100 nm to 100 pm.

15. A method of preparing the microcapsule according to claim 1, the method comprising: (a) preparing an oil-in-water emulsion of (i) an oil phase comprising a polymer or pre-polymer, and at least one lipophilic core, and (ii) an aqueous phase comprising at least one stabilizer or emulsifier; (b) optionally, adding to the oil phase at least one catalyst, at least one diluent or at least one initiator; (c) optionally, heating the oil-in-water emulsion to a temperature of 25 °C to 100 °C under stirring; (d) forming the polymeric microcapsule shell by cooling, or by in-situ oil-in-water reaction of the polymer or pre-polymer; and (e) obtaining the lipophilic core encapsulated in a polymeric microcapsule shell.

16. The method according to claim 15, wherein the diluent or solvent is selected from the group consisting of hydrocarbon oils, alkanes, ester oils, aliphatic esters and alkylene carbonates.

17. The method according to claim 15, wherein the oil phase is homogenous and prepared by optionally heating to a temperature of 100 °C.

18. The method according to claim 15, wherein the aqueous phase optionally further comprises at least one additive selected from the group consisting of surfactants, antifoams, rheology modifiers, thickeners, partitioning inhibitors, radical inhibitors, catalysts, radical initiators or combinations thereof.

19. The method according to claim 18, wherein - the stabilizer or emulsifier is selected from the group consisting of polyvinyl alcohol, hydroxyethyl cellulose and polyvinyl pyrrolidone; and - the antifoam is selected from the group consisting of liquid hydrocarbons, hydrophobic silicas, fatty acids, alkoxylated compounds, polyethers, polyalkylene glycols and non-ionic emulsifiers.

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