LIGHT-RESISTANT ENCAPSULATED PHEROMONE FORMULATIONS

Abstract

The present invention relates to pheromone microcapsules comprising carbon black particles, as well as their manufacturing process and their use in the protection of crops exposed to sunlight or artificial light.

Description

Title of the invention: Encapsulated irradiation-resistant pheromone formulations BRIGHT TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to encapsulated pheromone formulations resistant to light radiation. More particularly, it relates to pheromone microcapsules comprising carbon black particles, as well as their manufacturing process and their use in protecting plants and crops against pests such as insects or mammals, particularly in the event of exposure to light. STATE OF THE ART

[0002] Pheromone encapsulation is a preferred method for delivering these active ingredients in crops, parks, gardens, or forests, particularly for pheromones useful for attracting pests or disrupting their reproduction through a mating disruption mechanism. The pheromones thus delivered can be either insect or mammal pheromones.

[0003] The natural function of a pheromone is to carry information from one individual of a species to other individuals to trigger a specific reaction. These pheromones are molecules or mixtures of molecules with very precise stereochemistry and component ratios. In the world of plant protection products, their effects in the field must last for periods ranging from 4 weeks to 6 months. While encapsulation slows the diffusion of the pheromone by evaporation, it does not guarantee the duration of the product's effectiveness if the stability of the active ingredients in the capsules, before evaporation, has not been considered. Several examples of pheromones can illustrate this point, depending on the animal families concerned. Table 1 below illustrates the pheromones of certain Lepidoptera containing conjugated unsaturated compounds. Insect (lepidoptera) Main component of the pheromone Lobesia (I) fX Lz- ~ .os Carpocapse Mineuse of the tomato z ? , (HD Mineuse du marronnier (IV) Processionnaire du pin (V) t O v « ■ Amyelois transitella (navel orangeworm en anglais) (vd <.< Æ7\ « Æ7\ . / P Grapholita molesta VIII) (IX) Ectomyelois ceratoniae (Pyrale de lath datte or Caribbean worm) (X___) en anglais \ 12 / ® n —j't Cf' Thaumetopoea processionea (Oak procession) „ K (XI) .•-'''a .A''' . S 4 » SJ & ,U. ■ n

[0005] Similarly, the alarm pheromone of a large number of aphids is [3-farnesene of the following structure (VII):

[0006] [Chem. (VII)]

[0007] This pheromone is also an attractant for aphid predators and can be used for this property to protect crops. It is sensitive to light (visible or UV) and any change in geometry or functionality alters the use of the molecule as an information carrier for insects (both for the aphid and for its predators).

[0008] The following compound of structure (XII) is an analogue of the principal sex pheromone of the date moth:

[0009] [Chem. (XII)] 5 / A......." ■;....... / ......'or"A= u

[0010] All compounds (I) to (VI) and (VIII) to (XI) are major components of the female sex pheromones of these species. A change in a structural parameter of these molecules renders them ineffective. In particular, isomerization of the cis double bonds extinguishes the activity of these compounds. This isomerization can be induced by free radicals but also by interactions with photons of varying wavelengths.

[0011] Numerous academic studies have investigated the phenomena leading to the isomerization of these compounds during storage (absence of light) and in the field (exposure to daylight and air). For example, Brown et al. (Economic Entomology, vol. 79, no. 4, 1986, p. 923) studied elastomer-based formulations impregnated with pheromones (I) and (II) to limit the impact of light on these pheromones. They showed, as did other subsequent work (see J. Vrkoc et al. J. of Chem. Ecology, 4, 5, 1988, p. 1347), that the choice of material is essential for good pheromone stability during storage and field use, with red elastomers performing less well than black elastomers. These elastomers themselves perform less well than gray elastomers. According to these authors, the factor most favoring the isomerization of pheromones is primarily the type of vulcanization used to manufacture the elastomers: sulfur vulcanization, which generates disulfide, induces a very high rate of isomerization, while vulcanization with cross-linked phenolic resins, methanes, or peroxides does not induce isomerization. Since pheromones are often a very expensive component of plant protection formulations for mating disruption or other pest control techniques, it is necessary to optimize their stability during use to maximize their effectiveness, which lies in their diffusion in the air.

[0012] When it comes to stabilizing these pheromones based on compounds containing conjugated photosensitive unsaturated systems, those skilled in the art have used chemical stabilizers.

[0013] For example, in US5364969, the authors describe the use of a phenolic antioxidant (such as butylhydroxytoluene or BHT) in combination with an anti-UV additive: Tinuvin® 536 from the benzotriazole family. In US6252106, the anti-UV compound Tinuvin® P, a benzotriazole, is used at concentrations ranging from 0.1% to 10% by weight relative to the pheromone.

[0014] In WO2002 / 080672, the authors mix pheromones with di-tert-butyl-2,2'-methylenedi-p-cresol (MBMBP) as an antioxidant, and this mixture is used with any type of pheromone diffuser such as microcapsules (e.g., urea-based, gelatin-based, or liposome-based microcapsules), microbeads, laminated plastic flakes, and larger mechanical devices such as hollow fibers or twist ties. The authors indicate that this antioxidant can be combined with UV blockers such as carbon black or titanium dioxide, but no specific example supports this possibility, even less so in the context of using microcapsules. Indeed, since these mineral fillers have particle sizes on the order of microns, their insertion into microcapsules does not appear straightforward.At best, one can consider the simultaneous presence of pheromone microcapsules and carbon black, or the use of other, larger-scale diffusion systems.

[0015] In WO2017 / 050956A1 and WO2016 / 131883A1, the applicant described a particular method for encapsulating pheromones which is notable for not requiring chemical reactions to construct the microcapsules. These microcapsules organize themselves under the influence of the attractive and repulsive forces of fatty components and water, controlled by a HASE (Hydrophobic Alkali Swellable Emulsion) type additive. In these applications, the pheromone stabilizers are chemical molecules soluble with the pheromone and remaining at the core of the microcapsules. The stabilizing molecules are tert-butyl hydroquinone, propyl gallate, and t- Butylhydroxyanisole, p-methylhydroxybenzoate, N,N-diethyltoluamide, BHT, alpha-thioglycerin, nitroxides, and alkoxyamines are known antioxidants and UV sintering agents. The resulting particle sizes range from 0.1 to 10 µm, making it difficult to introduce carbon blacks of similar dimensions.

[0016] The current state of the art therefore does not describe a way to introduce carbon blacks into microcapsules containing pheromones which could nevertheless solve the problem of the photosensitivity of pheromones in microcapsules used as diffusers.

[0017] Carbon blacks are produced industrially using various processes such as those described in US patent 9574087. These powders are in the form of primary particles grouped together, agglomerated into clusters. The size of the primary particles can be on the order of a few tens of nanometers, while the agglomerates have sizes on the order of several hundred nanometers. The properties imparted by carbon blacks to the materials in which they are dispersed are always related to the state of dispersion of the carbon black in that material. Typical applications of carbon blacks are in the fields of plastics (e.g., piping), elastomers (e.g., vehicle wheels), inks and varnishes, and paints. In addition to mechanical properties, carbon blacks provide important electromagnetic properties (conductivity, absorption of radiation across a broad spectrum, for example).The problem of carbon black dispersion is specific to each type of use because carbon blacks are both very hydrophobic and very poorly dispersible in non-polar organic media.

[0018] The applicant has not found any example in the prior art of combining carbon blacks and pheromones efficiently, and in particular in microencapsulated formulations of pheromones.

[0019] However, when it comes to stabilizing the stereochemistry of pheromones comprising conjugated systems such as (I) to (IX) pheromone compounds, chemical antioxidants or anti-UV agents are not sufficient to maintain the correct isomerism when pheromone diffusers are exposed to sunlight, and the use of carbon blacks could provide an economical and effective solution to this problem.

[0020] A particularly illustrative case is that of compound (VI), for which commercial products must include opaque containers to preserve the molecule for several months in the field. For example, aerosol sprays from the Semios or Suterra brands can be mentioned (see J. Beck, Journal of Agricultural and Food Chemistry, 2012, 60, 8090).

[0021] Another product from Suterra, Check Mate F Now (EPA registration number: 56336-38), is in the form of a suspension of pheromone microcapsules in water containing 1.16% of the compound (VI). This product covers a culture for only 30 days, which is less than the theoretical evaporation time of the compound, indicating a loss of active ingredient through chemical degradation.

[0022] There is therefore still a need to develop new light-sensitive pheromone formulations that protect these pheromones from the harmful effects of light and prolong the effectiveness of these formulations over time. Summary of the invention

[0023] The present invention thus relates to microcapsules having a median diameter D50 ranging from 0.5 pm to 20 pm, preferably from 1 pm to 10 pm, containing a pheromone and carbon black particles.

[0024] Preferably, the microcapsules according to the invention comprise: • a core comprising a mixture of wax, oil, pheromone (e.g. insect or mammal pheromone), and carbon black particles, preferably whose primary particles have a median diameter D50 ranging from 10 nm to 50 nm, and • a solid outer shell surrounding the core.

[0025] The envelope may more particularly comprise a HASE-type copolymer, possibly neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt.

[0026] The core may also include one or more additives, preferably selected from a dispersing additive, preferably non-ionic, carbon black particles, a UV stabilizer, an antioxidant, and a mixture thereof. Preferably, the core includes a dispersing additive, preferably non-ionic, and carbon black particles.

[0027] The presence of carbon black particles in the microcapsules protects the pheromone also present in these microcapsules from light radiation and prevents its degradation and / or isomerization in the presence of light. The integrity of the pheromone is thus preserved during its exposure to light, resulting in a longer-lasting effect.

[0028] The present invention therefore also relates to the use of the microcapsules according to the invention, for the protection of a plant (in particular a crop) or a harvest against insects or mammals, in particular when said plant or harvest is exposed to light (e.g. sunlight or artificial light).

[0029] The present invention also relates to a method for manufacturing the microcapsules according to the invention. This method comprises mixing the ingredients forming the the core of the microcapsules, namely wax, oil, pheromone (for example, insect or mammal pheromone), carbon black particles, and possible additive(s), the formation of the microcapsule cores from this mixture and their coating with the material constituting the outer shell. This process can employ any microcapsule formation technique, i.e., deposition of a shell around a core, known in art.

[0030] When the outer shell comprises a HASE-type copolymer, said process advantageously comprises:

[0031] (a) the preparation of a fatty phase comprising wax, oil, pheromone (by (e.g., insect or mammal pheromone), and carbon black particles, and possibly one or more additives when present, the oil phase having a temperature higher than the melting point of the wax,

[0032] (b) the preparation of an aqueous solution comprising the HASE-type copolymer, the aqueous solution having a pH greater than or equal to 7.6, in particular greater than or equal to 8, especially from 8 to 10, and a temperature substantially identical to that of the oil phase,

[0033] (c) the addition of the oil phase to the aqueous solution comprising the type copolymer HASE, and agitation so as to form a dispersion of oil phase droplets in the aqueous solution, and

[0034] (d) acidification to a pH of 6 to 7.5, preferably 6.5 to 7.2. DETAILED DESCRIPTION OF THE INVENTION

[0035] The present invention therefore relates to microcapsules containing both pheromone-type active ingredients and carbon black particle-type fillers which make it possible to stabilize these active ingredients when exposed to light, typically during field use, thus increasing the duration of effectiveness of these active ingredients. Microcapsules

[0036] The microcapsules according to the invention have a median diameter D50 ranging from 0.5 pm to 20 pm, preferably from 1 pm to 10 pm, and comprise a core containing the pheromone-type active ingredient(s) and the carbon black particle-type fillers, this core being surrounded by a solid outer shell.

[0037] For the purposes of this invention, the "median diameter D50" of microcapsules means the median diameter of a distribution of microcapsules, that is, the diameter such that 50% of the microcapsules by volume have a diameter less than or equal to this value and 50% of the microcapsules by volume have a diameter greater than this value. It is measured by laser diffraction, in particular using a Mastersizer 3000 instrument, specifically according to the method described in the experimental section.

[0038] For the purposes of this invention, "pheromone" means a substance A pheromone is a chemical substance or mixture of chemical substances emitted by an animal, or an analog of such a chemical substance or mixture, that acts as a stimulus for individuals of that animal species. Such molecules can also stimulate individuals of other species; for example, the territorial pheromone of a predator like the fox can be perceived as a danger signal by rodent species. Pheromones can be produced either by living organisms or through chemical synthesis. More specifically, a pheromone is a chemical substance or mixture of chemical substances emitted by an animal.

[0039] Preferably, the pheromones used in the context of the present invention carry a photosensitive function, such as one or more unsaturations, preferably conjugated unsaturations.

[0040] By "unsaturation", we mean, in the context of the present invention, a double C=C bond or a triple C=C bond.

[0041] By "conjugated unsaturations", we mean, in the context of the present invention, an unsaturation as defined above linked to another unsaturation as defined above by a simple bond.

[0042] The pheromone will more particularly be an insect or mammal pheromone or possibly an analogue thereof, such as a lepidopteran pheromone (such as a lepidopteran of the genus Lobesia, the codling moth, the tomato leafminer (Tuta absoluta), the horse chestnut leafminer, the pine processionary moth, Amyelois transitella, Grapholita molesta, the date palm moth or the oak processionary moth), or an aphid pheromone, or possibly an analogue thereof, or a mixture thereof.

[0043] The pheromone may be a long-chain unsaturated lepidopteran pheromone, a terpene such as any of the molecules (I) to (VI), (VIII), (IX), and (X) to (XII) above, a sesquiterpene such as molecule (VII) above, or a mixture of these.

[0044] The pheromone may be more particularly chosen from molecules (I) to (XII) above and their mixtures, in particular from molecules (I) to (IX) above and their mixtures.

[0045] Carbon black particles consist of primary particles that can agglomerate together to form agglomerates. Preferably, the primary particles are not, or are only weakly, agglomerated in the microcapsules according to the invention. They are therefore preferably dispersed within the microcapsules.

[0046] Preferably, the primary particles of the carbon black particles used in the context of the present invention have a median diameter D50 ranging from 10 nm to 50 nm, in particular from 1 nm to 40 nm, for example from 1 inm to 30 nm, in particular from 12 nm to 20 nm.

[0047] By “median diameter D50” of primary carbon black particles, we mean, for the purposes of the present invention, the median diameter of a distribution of primary carbon black particles, that is to say, the diameter such that 50% of the particles by volume have a diameter less than or equal to this value and 50% of the particles by volume have a diameter greater than this value. It is measured by electron microscopy, in particular as described in EA Grulke, SB Rice, J. Xiong, K. Yamamoto, TH Yoon, K. Thomson, M. Saffaripour, G. Smallwood, JW Lambert, AJ Stromberg, R. Macy, N. Briot, D. Qian, Size and shape distributions of carbon black aggregates by transmission electron microscopy, Carbon (2018).

[0048] Preferred carbon black particles are carbon black particles intended for applications in inks and surface coatings, such as grades 430, 700, 800, 1100 and 1300 of the Monarch® brand or grades 1200, 1600 and 1800 of the Emperor® brand of Cabot or grades of the Special Black, Printex®, Arosperse® and NIPex® brands of Orion Specialty Carbon Blacks.

[0049] Preferably, the microcapsules according to the invention comprise a core containing the pheromone-type active ingredient(s) and the carbon black particle-type fillers, this core being surrounded by a solid outer shell.

[0050] Core of the microcapsules

[0051] The core of the microcapsules advantageously represents 90% to 99.9% by weight of the weight of the microcapsules.

[0052] The core comprises a mixture of pheromone (for example from insect or mammal) and carbon black particles, and advantageously a wax and an oil.

[0053] Preferably, the core comprises, in particular, a mixture of wax, oil, pheromone (for example, insect or mammalian), carbon black particles, and one or more additives, preferably selected from a dispersing additive, preferably non-ionic, carbon black particles, a UV blocker, an antioxidant, and a mixture thereof. Preferably, the core comprises a dispersing additive, preferably non-ionic.

[0054] The heart will advantageously contain, in relation to the weight of the heart: • from 0.5% to 30%, in particular from 0.5% to 20%, especially from 1% to 15%, preferably from 1% to 10%, by weight of pheromone (for example from insect or mammal), • from 0.01% to 10%, preferably from 0.1% to 5%, by weight of carbon black particles, • from 0.5% to 50%, in particular from 0.5% to 30%, especially from 1% to 25%, preferably from 1% to 20%, by weight of wax, and • 20 to 95%, in particular 30 to 90%, preferably 40 to 80%, by weight of oil.

[0055] The heart will preferably contain, relative to the weight of the heart: • from 0.5% to 30%, in particular from 0.5% to 20%, especially from 1% to 15%, preferably from 1% to 10%, by weight of pheromone (for example from insect or mammal), • from 0.01% to 10%, preferably from 0.1% to 5%, by weight of carbon black particles, • from 0.5% to 50%, in particular from 0.5% to 30%, especially from 1% to 25%, preferably from 1% to 20%, by weight of wax, • from 20% to 95%, in particular from 30% to 90%, preferably from 40% to 80%, by weight of oil, and • up to 10% (e.g. 0.01% to 10%), in particular up to 5%, preferably 0.1% to 5%, by weight of a dispersing additive, preferably non-ionic, of carbon black particles relative to the weight of the core.

[0056] Preferably, the dispersing additive, preferably non-ionic, of carbon black particles is present in the core in a weight quantity less than or equal to that of the carbon black particles.

[0057] In particular, the core may contain up to 10% (e.g. 0.01% to 10%), in particular up to 5%, preferably from 0.1% to 5%, of one or more additives.

[0058] For the purposes of this invention, "wax" means a lipophilic compound that is solid at room temperature (approximately 25°C) and atmospheric pressure (1013.25 hPa), preferably of natural origin. Preferably, the wax has a melting point above 45°C at atmospheric pressure.

[0059] Waxes that can be used in a composition according to the invention may be chosen from animal waxes, vegetable waxes, mineral waxes, synthetic waxes, and mixtures thereof. Examples of animal waxes include beeswax, lanolin wax, and Chinese insect wax. Examples of vegetable waxes include rice wax, camauba wax, candelilla wax, jojoba wax, ouricurry wax, esparto grass wax, cork fiber wax, sugar cane wax, Japanese wax, and sumac wax. Examples of mineral waxes include montan wax, microcrystalline waxes, paraffins, and ozokerite. Examples of synthetic waxes include polyethylene waxes, waxes obtained by Fisher-Tropsch synthesis, and waxy copolymers and their esters.The hydrogenated derivatives of the waxes mentioned above can also be used as waxes within the scope of the present invention. Other examples include waxes obtained by catalytic hydrogenation of animal or vegetable oils having unsaturated, linear or branched C8-C32 fatty acid chains. Among these, hydrogenated jojoba oil and [other oil] may be mentioned. Hydrogenated sunflower oil, hydrogenated castor oil, hydrogenated coconut oil, or hydrogenated lanolin oil, as well as di-(trimethylol-1,1,1-propane tetrastearate, can be used. Waxes obtained by transesterification and hydrogenation of vegetable oils, such as castor or olive oil, can also be used, like the waxes sold under the names Phytowax ricin 16L64®, Phytowax ricin 22L73® and Phytowax Olive 18L57® by the company SOPHIM.

[0060] Advantageously, the wax is chosen from the group consisting of beeswax, lanolin wax, Chinese insect wax, rice wax, camauba wax, candelilla wax, jojoba wax, ouricurry wax, alfa wax, cork fiber wax, sugar cane wax, Japanese wax, sumac wax, montan wax, microcrystalline waxes, and mixtures thereof.

[0061] For the purposes of this invention, "oil" means a fatty compound, liquid at room temperature and atmospheric pressure, immiscible with water and non-volatile.

[0062] The oil according to the invention may be chosen from vegetable oils, animal oils, synthetic oils, and mixtures thereof; preferably chosen from vegetable oils, animal oils, and mixtures thereof. The vegetable oil will advantageously be chosen from the group consisting of sunflower oil, peanut oil, soybean oil, rapeseed oil, corn oil, olive oil, grape oil, walnut oil, linseed oil, palm oil, coconut oil, argan oil, avocado oil, almond oil, hazelnut oil, pistachio oil, rice oil, cottonseed oil, wheat germ oil, sesame oil, and mixtures thereof. The oil of animal origin will be advantageously chosen from the group consisting of cod liver oil, shark oil and their mixtures.

[0063] One or more additives may also be present in the core of the microcapsules, preferably chosen from a dispersing additive, preferably non-ionic, carbon black particles, an anti-UV additive, an antioxidant and a mixture of these.

[0064] The dispersing additive, preferably non-ionic, for the carbon black particles can be Disperbyk® 163 from Byk Chemie or Borchi® Gen 0451 from Borchers. Such dispersants can be prepared according to EP2091984 or EP2125909, the teachings of which are incorporated by reference concerning the compositions and copolymers useful as dispersing agents.

[0065] Anti-UV additives or antioxidants well known to those skilled in the art may be added to limit oxidation reactions caused by oxygen on the surface of the particles, such as tert-butylhydroxytoluene (BHT), tert-butylhydroxyanisole (BHA), tocopherol, oxybenzone, octabenzone, derivatives of the benzotriazole family (such as 2-(2'-hydroxy-3',5'-tertamylphenyl)benzotriazole, or 2-(2'-hydroxy-3'-tert-butyl-5'-methyl-phenyl)-5-chlorobenzotriazole), propyl gallate, or derivatives of 4-tetramethyl-piperidine, notably known as HALS ("hindered amine light stabilizers") and described in Schaller, C., Rogez, D. & Braig, A. "Hindered amine light stabilizers in pigmented coatings." J Coat Technol Res 6, 81-88 (2009), and its nitroxides (obtained by oxidation of HALS as indicated in FR2788272).

[0066] Microcapsule shell

[0067] The envelope will advantageously comprise a HASE-type copolymer, optionally neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt.

[0068] By "HASE-type copolymer" (HASE being the abbreviation for "Hydrophobically modified Alkali Swellable Emulsion," i.e., an emulsion that can swell in an alkaline medium and is hydrophobically modified), the present invention means a copolymer of (meth)acrylic acid (e.g., methacrylic acid), alkyl acrylate (e.g., ethyl acrylate), and one or more hydrophobic macromonomers of the following Chem. A formula:

[0069]

[0070] in which: • m is an integer greater than or equal to 5, preferably between 10 and 30, and • R a hydrocarbon group of formula CnH2n+i in which n is an integer between 9 and 25, preferably between 10 and 22, and even more preferably equal to 12, 16, or 22. Group R is therefore hydrophobic

[0071] By "neutralized, totally or partially", it is understood, in the context of the present invention, that all or part of the carboxylic acid (COOH) functions carried by the HASE type copolymer are in salt form, and more particularly in the form of sodium, potassium or ammonium salt.

[0072] Advantageously, the HASE-type copolymer comprises, in particular, is made up of, with respect to the total weight of the copolymer: • between 30% and 40% by weight of repeating units derived from methacrylic acid, • between 45% and 60% by weight of repeating units derived from ethyl acrylate, and • between 5% and 20% by weight of repeating units derived from a macromonomer of the following Chem formula:

[0073]

[0074] in which: • m is an integer greater than or equal to 5, preferably between 10 and 30, and • R a hydrocarbon group of formula CnH2n+i in which n is an integer between 9 and 25, preferably between 10 and 22 and preferably equal to 12.

[0075] The HASE-type copolymer can be prepared, for example, according to one of the methods described in WO2011 / 104599, WO2011 / 104600 and EP1778797. This could be Pharma 38 or Viscoatex 730LV from Coatex. Manufacturing process

[0076] The microcapsules according to the invention can be prepared according to the process described above, and in particular according to steps (a) to (e) when the outer shell comprises a HASE-type copolymer. The microcapsules will advantageously be prepared in the form of an aqueous suspension.

[0077] Step (a)

[0078] The oil phase is prepared in step (a) so as to obtain a mixture of wax, oil, pheromone (for example insect or mammal pheromone), carbon black particles, and one or more additives (preferably chosen from a dispersing additive, preferably non-ionic, carbon black particles, an anti-UV additive, an antioxidant and a mixture of these) having the core composition described above.

[0079] The oil phase is maintained, preferably under agitation, at a temperature above the melting point of the wax so as to be liquid. In a particular embodiment, the oil phase is at a temperature of 50°C to 85°C, in particular 60°C to 80°C.

[0080] Advantageously, the oil phase is prepared by mixing the oil and the additive(s) (in particular the dispersing additive, preferably non-ionic, of carbon black particles) which is heated to a temperature above the melting temperature of the wax, then adding the wax, then adding the carbon black particles and the pheromone.

[0081] Step (b)

[0082] The aqueous solution of step (b) may be prepared by basifying an aqueous solution comprising the HASE-type copolymer by adding a base, so as to obtain a pH greater than or equal to 7.6 (e.g., from 7.6 to 10), in particular greater than or equal to 8, in particular from 8 to 10. This base shall advantageously be chosen from sodium or potassium carbonate, ammonium hydroxide, or ammonia. aqueous solution, sodium hydroxide, potassium hydroxide and their combinations.

[0083] Advantageously, the aqueous solution comprises from 0.1% to 10%, in particular from 0.1% to 5%, preferably from 0.1% to 1%, by weight of the HASE-type copolymer relative to the weight of the aqueous solution.

[0084] This aqueous solution is then heated to a temperature substantially identical to that of the oil phase.

[0085] By "temperature substantially identical" to that of the oil phase, advantageously means a temperature not varying by more than 10°C, in particular by more than 5°C, from the temperature of step (a). Preferably, the temperature of step (b) will be identical to that of step (a).

[0086] Thus, the aqueous solution is advantageously at a temperature of 50°C to 85°C, in particular from 60°C to 80°C.

[0087] Step (c)

[0088] In this step, the oil phase having the temperature of step (a) is added to the aqueous solution having the temperature of step (b). The oil phase droplets formed in the aqueous solution will form the core of the microcapsules.

[0089] Step (d)

[0090] Acidification causes the HASE-type copolymer present in the aqueous solution to precipitate onto the droplets, which then become microcapsules comprising a core based on the oil phase surrounded by a solid shell based on the HASE-type copolymer. These particles are dispersed in water, thus forming an aqueous suspension of the microcapsules.

[0091] In a particular embodiment, acidification is carried out by adding an acid such as hydrochloric acid, phosphoric acid, sulfuric acid, an organic acid of the carboxylic acid type (particularly acetic acid or propionic acid) or a mixture of these, in particular phosphoric acid, until a pH of 6 to 7.5, preferably 6.5 to 7.2, is reached. This acid is preferably added in the form of an aqueous solution.

[0092] The temperature of the aqueous suspension of the microcapsules thus obtained is then advantageously brought to a temperature below the melting point of the wax, in particular to a temperature between 20°C and 30°C.

[0093] According to a particular embodiment, the process implements the steps below. - First step (step (a)): In a mixer equipped with a heating system and mechanical stirring, the oil and the additive(s), such as the dispersing additive, preferably non-ionic, of carbon black particles, are mixed and brought to a temperature above the melting point Wax is added, then more wax is added. The mixture is homogenized before adding the carbon black particles and the pheromone. This phase represents a quantity Q expressed in kilograms. - Second step (step (b)): In a reactor equipped with a high-shear stirrer, water, preferably in a quantity Q, and the HASE-type copolymer, preferably at a concentration of 0.1% to 10% w / w, in particular 0.1% to 5% w / w, preferably 0.1% to 1% w / w, are mixed, and then the pH is brought to a value greater than or equal to 8, in particular 8 to 10, by means of a basic solution, preferably at a concentration of 5% to 10% w / w, of sodium hydroxide, potassium hydroxide, or ammonia. When the solution is clear, the temperature is brought to the temperature of the mixture in the first step. - Third step (step (c)): The mixture from the first step (oil phase) is added to the aqueous phase while stirring to form droplets. Once the addition is complete, stirring can be continued, for example for 10 minutes to 2 hours. - Fourth step (step (d)): The pH is adjusted to a value of 6 to 7.5, preferably 6.5 to 7.2, using an acid solution, such as phosphoric acid, sulfuric acid, or hydrochloric acid, in particular at a concentration of 2 to 10% by weight. Acidification allows the HASE-type copolymer to coalesce on the surface of the droplets, thus forming the solid shell around the microcapsule cores. The resulting aqueous suspension of the microcapsules is then brought to room temperature, possibly with stirring. Use

[0094] The present invention also relates to the use of the microcapsules according to the invention for the protection against insects or mammals of a plant (in particular a crop) or a harvest, in particular when said plant or harvest is exposed to light, for example sunlight or artificial light.

[0095] Pheromones can be used to influence the behavior of animals such as insects (e.g., butterflies or aphids), rodents, or game animals (e.g., roe deer, red deer, fallow deer, wild boar) that cause damage to plants (particularly crops) and harvests. The pheromone(s) will be chosen according to the animal (e.g., insect or mammal) against which the plant or harvest is to be protected. For example, a pheromone could be chosen to lure a butterfly using a trapping protocol or a mating disruption protocol.

[0096] The microcapsules according to the invention, more particularly in the form of an aqueous suspension, may be applied using known techniques of the person skilled in the art on supports present in the storage area (walls, posts, floors...) or on bags containing the seeds.

[0097] In the case of plant protection, microcapsules, in particular in the form of an aqueous suspension, may more particularly be applied to plants, in particular to their foliage, for example by means of a spraying system.

[0098] The plants to be protected will advantageously be crops. These crops can be, for example, in the form of a covered plot (e.g. greenhouse, nursery) or an open plot (e.g. fields, forest).

[0099] Preferably, the plants to be protected are vines, field crops (rice, corn, cotton, soybeans, sunflowers, etc.), vegetable crops (tomatoes, salads, peppers, melons, cucumbers, cabbages, spinach, etc.), trees (e.g., fruit or ornamental trees (apple trees, peach trees, pear trees, citrus trees, almond trees, etc.), forests (pine forests, oak forests, etc.)), or shrubs (boxwood, etc.).

[0100] The crops to be protected will be, in particular, grains such as wheat, corn, etc. The aim will be to protect these grains during storage. FIGURES

[0101] [Fig.1]: photograph obtained by optical microscopy of the microcapsules obtained in example 1.

[0102] [Fig.2]: monitoring of the release over time of the pheromone (I) encapsulated in microcapsules with black particles placed in an oven at 30°C.

[0103] [Fig.3]: monitoring of the isomerization over time of the pheromone of formula (I) encapsulated in microcapsules with or without carbon black particles and subjected to light radiation (daylight). EXAMPLES

[0104] • The pheromones used in the examples are manufactured by the applicant according to methods known to those skilled in the art. The HASE-type copolymers used, namely Pharma 38 and Viscoatex 730VL, were commercially supplied by Coatex. The carbon black particles used in the examples consist of primary particles having a median diameter D50 of 14 to 20 nm. • The size of the microcapsules is measured by light diffraction analysis using a Mastersizer 3000 instrument with a laser beam diffraction pattern. The measurement protocol is as follows:

[0105] The samples are first prepared by dispersing 0.5 g of the formulation in 100 ml of demineralized water under magnetic stirring for 10 min. Then proceed To measure particle sizes, first align the instrument and measure the background noise to record the diffraction phenomena caused by the water. The sample is then introduced into the measuring cell, and five successive measurements are taken. The particle size is then determined by averaging these five measurements. • The analysis of pheromone levels is carried out by gas chromatography (GC) with a flame ionization detector on an Agilent - HP series II 5890 instrument. • Pheromone release studies are conducted in ventilated ovens without viewing windows to avoid exposure to light. These studies are performed using two methods: either by monitoring the weight loss of the samples, or by monitoring the residual concentration of the pheromone in the sample using gas chromatography (GC). • Accelerated aging studies under light to investigate photochemical degradation (e.g. isomerization) are carried out in daylight or in the laboratory using a tabletop solar simulator, the Solartest 1200. • Optical microscopy is performed on a ZEISS AXIO PLAN 2 microscope. Sample observations are made in transmission using a 40x plan and a 20x plan objective. A ZEISS AxioCam ICC3 camera allows the images to be viewed on a computer screen.

[0106] For example 3b, the pheromonal mixture of Grapholita molesta was used. This mixture is composed of the following two molecules (VIII) and (IX) in a ratio of 15 / 85:

[0107] [Chem. (VIII)]

[0108] [Chem. (IX)] Example 1: Microcapsules with pheromone (I)

[0109] In a 500 mL double-jacketed glass reactor equipped with mechanical stirring, 200 g of sunflower oil are introduced, followed by 2 g of Disperbyk® 163 (a carbon black particle dispersant). The mixture is heated to 80°C, then 90 g of purified beeswax are added. Once it has returned to 80°C, 2 g of Emperor® 1200 carbon black particles are added. After After a few seconds, the mixture turns a uniform black, and 15g of pheromone (I) are then added. The core formulation is left to stir while the outer formulation is prepared.

[0110] In a double-jacketed IL reactor equipped with a magnetic stirrer, 307 mL of deionized water are added, followed by 9.6 g of Viscoatex 730LV (equivalent to 3.2 g of dry matter). A 10% sodium hydroxide solution is then added dropwise until a pH of 8.5 is reached. This corresponds to a mass of 5.2 g of sodium hydroxide solution under stirring. The formulation becomes thick and translucent with bluish reflections. The temperature of the solution is then raised to 80°C.

[0111] Using a peristaltic pump, the core formulation is transferred into the IL reactor at a flow rate of 5 mL per minute. In order to prevent the oil phase from solidifying in the transfer pipes, these are immersed in a water bath at 80°C.

[0112] The viscosity of the medium gradually increases. At the end of the addition, stirring is maintained for an additional hour while the heating is stopped. When the temperature reaches 60°C, 11 mL of a 4% (wt) phosphoric acid solution is added while stirring vigorously. The formulation becomes fluid and reaches a pH of 6.7. Once the mixture has returned to room temperature, a gray microcapsule suspension is recovered.

[0113] Characteristics obtained: • Dry extract: 48% • Encapsulation rate T: 99.7%

[0114] T = (total quantity of (I) - quantity of (I) in water) / total quantity of (I) • Median diameter D50: 7 pm • Characterization by microscopy: see photo in [Fig.1]

[0115] This photo shows that the carbon black particles are inside the microcapsules. • Release of the pheromone in an oven at 30°C:

[0116] 2 g of the microcapsule suspension are deposited in plastic cups and The sample is placed in an incubator. The baseline (T0) of the study is 24 hours after this incubation. A sample is then analyzed regularly by measuring its weight and by gas chromatography (GC) to estimate the pheromone release under these conditions. For an 80-day study, a sample is collected on days 3, 7, 12, 20, 31, 40, 60, and 80.

[0117] The results obtained are shown in [Fig. 2]. Controlled release was observed over several weeks. Thus, the presence of carbon black particles in the microcapsules did not hinder encapsulation and the prolonged release of the pheromone. • Monitoring the isomeric ratio over time:

[0118] The results obtained are shown in [Fig. 3]. The measurements show that the isomerization of pheromone (I) is slower for the formulation with carbon black particles than for the control corresponding to the same formulation without carbon black particles. This illustrates the better stability of the pheromones in the microcapsules according to the invention.

[0119] Example 2: Microcapsules with pheromone (VI) and different concentrations of carbon black particles

[0120] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients mentioned in Table 2 below (the additive(s) being added immediately after the oil).

[0121] [Tables2] Microcapsule component Ingredient Example 2a Example 2b Example 2c Weight in g Core formulation Pheromone (VI) 3.00 3.03 2.95 Sunflower oil 64.83 65.13 65.33 Beeswax 0.65 0.63 0.68 Emperor® 1600 (carbon black) 0.63 0.33 0.15 BHT (antioxidant) 1.902 1.80 1.91 Shell formulation Demineralized water 166.86 167.86 167.83 Viscoatex 730LV (in g dry matter) 1.5 1.5 1.5 10% sodium hydroxide 2.73 2.73 2.73 4% H3PO4 4.53 3.65 3.58 Carbon black content relative to the core formulation: 0.9% 0.465% 0.2%

[0122] The encapsulation yields obtained with the three formulations 2a to 2c are presented in Table 3 below. They show that the presence of carbon black particles in the microcapsule, regardless of their content, does not impair the encapsulation of the pheromone in the microcapsules. Example 2a Example 2b Example 2c Total active substance content 1.19% 1.26% 1.19% Free active substance content 0.01% 0.003% 0.012% Encapsulation yield 99.19% 99.33% 98.94%

[0124] Example 3: Microcapsules with different pheromones and different formulations

[0125] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients mentioned in Table 4 below (the additive(s) being added immediately after the oil).

[0126] [Tables4] Microcapsule component Ingredient Example 3a Example 3b Example 3c Example 3d Weight in g Core formulation Pheromone 130.2 36.6 57.3 5.5 Sunflower oil 350.6 230.0 378.0 120 Beeswax 3.5 94.0 155.3 1.2 Emperor® 1600 (carbon black) 0.45 0.4 0.6 0.6 Oxybenzone (anti-UV additive) 11.9 - 8.9 0.7 BHT (antioxidant) 11.8 8.5 15.2 3.5 Shell formulation Demineralized water 500 800.0 1250.0 300.0 Pharma 38 (in g dry matter) 17.6 13.2 23.5 4.9 10% sodium hydroxide 30.5 23.6 41.7 8.8 4% H3PO4 1.9 17.6 47.8 10.5 Nature of the pheromone (II) (VIII) / (IX) (I) (VI)

[0127] The encapsulation yields obtained with the four formulations 3a to 3d are presented in Table 5 below. These yields are very good regardless of the formulation.

[0128] [Tables5] Example 3a Example 3b Example 3c Example 3d Total active substance content 12.3% 2.46% 2.7% 1.15% Free active substance content 0.45% 0.008% 0.01% 0.019% Encapsulation yield 97.6% 99.4% 99.63% 98.3%

[0129] Example 4: Pheromone (VI) microcapsules with different encapsulating polymers

[0130] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients mentioned in Table 6 below (the additive(s) being added immediately after the oil). Microcapsule component Ingredient Example 4a Example 4b Weight in g Core formulation Pheromone (VI) 10.8 10.5 Sunflower oil 231.8 231.7 Beeswax 23 23 Emperor® 1600 (carbon black) 1.16 1.16 BHT (antioxidant) 6.4 6.8 Shell formulation Demineralized water 600 572 Viscoatex 730LV (in g dry matter) 5.34 - Pharma 38 (in g dry matter) - 9.4 10% sodium hydroxide 9.7 16.8 4% H3PO4 13 19.85

[0132] This example shows that different HASE-type copolymers can be used to manufacture pheromone microcapsules according to the invention comprising carbon black particles.

[0133] Example 5: Effect of carbon black particles in the protection of pheromones

[0134] Microcapsules based on pheromone (VI) and various anti-UV additives in place of carbon black particles were prepared according to the process of Example 1 using the ingredients mentioned in Table 7 below (the additive(s) being added immediately after the oil). Microcapsule component Ingredient Ex. 5a* Ex. 5b Ex. 5c* Ex. 5d* Weight in g Core formulation Pheromone (VI) 2.97 3.08 3.00 3.03 Sunflower oil 45.71 48.40 45.70 46.30 Beeswax 18.60 19.38 18.60 18.60 Anti-UV additive 1.10 0.33 1.10 0.63 BHT (antioxidant) 1.80 1.88 1.90 1.90 Shell formulation Demineralized water 161.02 162.08 161.03 160.58 Pharma 38 (in g dry matter) 2.67 2.78 2.67 2.64 10% Sodium hydroxide 4.73 4.93 4.73 4.73 4% H3PO4 5.20 0.68 5.05 5.45 UV inhibitor studied Oxybenzone Carbon black Tinuvin® 571 TiO2

[0136] * comparative examples

[0137] The pheromone (VI) is very fragile and readily rearranges into the E,Z isomer under the effect of visible light. After exposing the microcapsules of Examples 5a to 5d to daylight on cardboard slides, the change in concentration of the different isomers remaining in the microcapsules is measured. The results obtained are presented in Table 8 below. Pheromone (VI) and isomer levels in microcapsules (Pheromone (VI) / isomer ratio) Example 5a Example 5b Example 5c Example 5d Day 0 100% (96 / 4) Day 5 92% 97% 95% 95% Day 10 85% 95% 90% 88% Day 15 79% (90.7 / 9.3) 92% (96 / 4) 84% (91.7 / 8.3) 83% (90.3 / 9.7)

[0139] These results demonstrate better stability (preservation of the initial isomeric ratio) of the active ingredient studied, namely pheromone (VI), in microcapsules according to the invention containing carbon black particles compared to microcapsules containing chemical anti-UV additives such as oxybenzone, Tinuvin® 571, or TiO2, and this at a 2 to 4 times lower additive content in the microcapsules. This demonstrates that the microcapsules according to the invention release the pheromone only in the form of its effective active ingredient, unlike the other microcapsules.

[0140] Example 6: Pheromone (VI) microcapsules with a high carbon black particle content

[0141] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients listed in Table 9 below. Microcapsule Portion Ingredient Example 6a Example 6b Weight in g Core Formulation Pheromone (VI) 12 24 Sunflower Oil 240 240 Beeswax 100 100 Emperor® 1600 (carbon black) 6 12 Disperbyk® 163 (dispersing agent) 6 12 Shell Formulation Demineralized Water 600 600 Pharma 38 (in g dry matter) 15 15 10% Sodium Hydroxide 9.7 9.5 4% H3PO4 13 12.8 Total Pheromone Content 1.2% 2.3% Pheromone Content in Cores 3.3% 6.2% Carbon Black Content in Microcapsules 1.6% 3.1%

[0143] Example 7: Microcapsules with low concentrations of pheromones (III), (IV) and (XI) for use as diffusers for trapping tomato leafminers, horse chestnut leafminers, and oak processionary caterpillars

[0144] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients listed in Table 10 below. Part of the microcapsule Ingredient Example 7a Example 7b Example 7c Weight in g Core formulation Pheromone 1 g of III 1 g of IV 1 g of XI Sunflower oil 70 70 70 Beeswax 30 30 30 Emperor® 1600 (carbon black) 0.2 0.2 0.2 Disperbyk® 163 (dispersing agent) 0.2 0.2 0.2 Shell formulation Demineralized water 100 100 100 Pharma 38 (in g dry matter) 3 3 3 10% sodium hydroxide 2.1 2.0 2.0 4% H3PO4 0 0 0 Nature of the pheromone (III) (IV) (XI)

[0146] These three formulations exhibit an encapsulation rate greater than 99%.

[0147] Example 8: Pheromone microcapsules (X) and (XII) for use in diffusers to control the date moth

[0148] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients listed in Table 11 below. Part of the microcapsule Ingredient Example 8a Example 8b Weight in g Core formulation Pheromone 20.8g of X 20.8g of XII Sunflower oil 106.4 106.4 Beeswax 43.2 43.2 Tinuvin® 571 2.1 2.1 BHT 4.1 4.1 Emperor® 1600 (carbon black) 0.9 0.9 Disperbyk® 163 (dispersing agent) 0.9 0.9 Shell formulation Demineralized water 100 100 Pharma 38 (in g dry matter) 6.1 6.1 10% sodium hydroxide 11.0 11.0 4% H3PO4 8.4 8.4 Nature of the pheromone (X) (XII)

[0150] These two formulations exhibit an encapsulation rate greater than 99%.

Claims

Demands

1. Microcapsules having a median diameter D50 ranging from 0.5 pm to 20 pm, comprising: - a core comprising a mixture of wax, oil, pheromone, and carbon black particles, the carbon black particles being made up of primary particles having a median diameter D50 ranging from 10 nm to 50 nm, and - a solid outer shell surrounding the core, the shell comprising a HASE-type copolymer, optionally neutralized, totally or partially, in the form of a sodium, potassium, or ammonium salt.

2. Microcapsules according to claim 1, characterized in that the carbon black particles are made up of primary particles having a median diameter D50 ranging from 10 nm to 40 nm, for example from 11 nm to 30 nm, in particular from 12 nm to 20 nm.

3. Microcapsules according to claim 1 or 2, characterized in that the pheromone carries a photosensitive function, in particular one or more unsaturations, preferably conjugated unsaturations.

4. Microcapsules according to any one of claims 1 to 3, characterized in that the pheromone is an insect or mammal pheromone or an analogue thereof, such as a lepidopteran pheromone, an aphid pheromone, an analogue thereof or a mixture thereof.

5. Microcapsules according to any one of claims 1 to 4, characterized in that the pheromone is selected from the following molecules (I) to (XII) and their mixtures: [Chem. (I)] [Chem. (II)] ^'"Q-Ac [Chem. (IV)] [Chem. (VI)] [Chem. (VII)] [Chem. (VIII)] [Chem. (X)] > 4. A i CK X). ,.-K xx xx .xx A 'Y -* Πy  X $ !> [Chem. (XII)] 7 x 5 \ s / i;. HAS

6. QX Microcapsules according to any one of claims 1 to 5, characterized in that the core represents from 90% to 99.9% by weight of the weight of the microcapsules.

7. Microcapsules according to any one of claims 1 to 6, characterized in that the core contains, relative to the weight of the core: - from 0.5% to 30%, in particular from 0.5% to 20%, in particular from 1% to 15%, preferably from 1% to 10%, by weight of pheromone, - from 0.01% to 10%, preferably from 0.1% to 5%, by weight of carbon black particles, - from 0.5% to 50%, in particular from 0.5% to 30%, in particular from 1% to 25%, preferably from 1% to 20%, by weight of wax, and - from 20% to 95%, in particular from 30% to 90%, preferably from 40% to 80%, by weight of oil.

8. Microcapsules according to any one of claims 1 to 7, characterized in that the core further contains a dispersing additive, preferably non-ionic, for carbon black particles.

9. Microcapsules according to claim 8, characterized in that the core contains up to 10%, in particular from 0.01% to 10%, preferably from 0.1% to 5%, by weight of additive dispersing carbon black particles relative to the weight of the core.

10. Microcapsules according to claim 8 or 9, characterized in that the carbon black particle dispersing additive is present in the core in a weight quantity less than or equal to that of the carbon black particles.

11. Microcapsules according to any one of claims 1 to 10, characterized in that the core further contains an anti-UV additive, an antioxidant or a mixture thereof.

12. Use of the microcapsules according to any one of the claims

13.

14.

15. 1 to 11, for the protection of a plant or crop against insects or mammals, in particular when said plant or crop is exposed to light. A method for manufacturing microcapsules according to any one of claims 1 to 11 comprising: (a) the preparation of a grease phase comprising the wax, oil, pheromone, and carbon black particles, and optionally one or more additives when present, the grease phase having a temperature higher than the melting point of the wax, (b) the preparation of an aqueous solution comprising 0.1% to 10% by weight of the HASE-type copolymer relative to the weight of the aqueous solution, the aqueous solution having a pH greater than or equal to 7.6, in particular greater than or equal to 8, in particular 8 to 10, and a temperature substantially identical to that of the oil phase, (c) the addition of the oil phase to the aqueous solution comprising the HASE-type copolymer and agitation so as to form a dispersion of oil phase droplets in the aqueous solution, and (d) acidification to a pH of 6 to 7.5, preferably 6.5 to 7.

2. Process according to claim 13, characterized in that the temperature at step (a) and at step (b) ranges from 50°C to 85°C. A process according to claim 13 or 14, characterized in that the aqueous solution prepared in step (b) comprises from 0.1% to 5%, preferably from 0.1% to 1% by weight of the HASE-type copolymer relative to the weight of the aqueous solution.