Encapsulated pheromone formulations resistant to light radiation

Abstract

The present invention relates to pheromone microcapsules having a median diameter D50 ranging from 0.5 µm to 20 µm and comprising carbon black particles, as well as to a process for the production thereof and to the use thereof in the protection of crops exposed to sunlight or artificial light.

Description

[0001] DESCRIPTION

[0002] TITLE: FORMULATIONS OF ENCAPSULATED PHEROMONES RESISTANT TO LIGHT RADIATION

[0003] TECHNICAL FIELD OF THE INVENTION

[0004] 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 a method of manufacturing the same and their use in protecting plants and crops against pests such as insects or mammals, particularly when exposed to light.

[0005] STATE OF THE ART

[0006] Pheromone encapsulation is a method of choice for delivering these active ingredients to crops, parks, gardens, or forests, particularly for pheromones useful for attracting pests or disrupting their reproduction through a mating disruption mechanism. The pheromones vectorized in this way can be insect pheromones as well as mammalian pheromones.

[0007] The natural function of a pheromone is to carry information from one individual of a species to other individuals to provoke a specific reaction. These pheromones are molecules or mixtures of molecules that are very precise in terms of stereochemistry and in terms of the ratio of components. In the world of plant protection products, their actions in fields must last for periods ranging from 4 weeks to 6 months. While encapsulation can slow down the diffusion by evaporation of the pheromone, it does not guarantee the duration of effectiveness of the product if the stability of the active ingredients in the capsules, before their evaporation, has not been considered. Several examples of pheromones can illustrate this point according to the families of animals concerned. Table 1 below illustrates the pheromones of certain lepidopterans containing conjugated unsaturated compounds. [Table 1]

[0008] Similarly, the alarm pheromone of many aphids is -farnesene with the following structure (VII):

[0009] [Chem. (VII)]

[0010] This pheromone is also an attractant of 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 molecule's use as an information vector for insects (both for the aphid and for its predators).

[0011] The following compound of structure (XII) is an analogue of the main sex pheromone of the date moth:

[0012] [Chem. (XII)]

[0013] All compounds (I) to (VI) and (VIII) to (XI) are the major components of the sex pheromones of females of the species. Changing a structural parameter of these molecules renders them ineffective. In particular, isomerizations of the cis double bonds extinguish the activity of these compounds. These isomerizations can be caused by free radicals but also by interactions with photons of varying wavelengths.

[0014] Many academic studies have investigated the phenomena leading to the isomerization of these compounds during storage (absence of light) and in the field (exposed to daylight and air). Thus, Brown et al. (Economie Entomology, vol. 79, n°4, 1986, p. 923) studied formulations based on elastomers impregnated with pheromones (I) and (II) to limit the impact of light on these pheromones. They show, as other subsequent works (see J. Vrkoc et al. J. of Chem. Ecology, 4, 5, 1988, p. 1347), that the choice of material is essential for good stability of the pheromones during storage and during use in the field, with red elastomers having a poorer performance than black elastomers, which themselves have a poorer performance than gray elastomers.According to these authors, the factor most favoring the isomerization of pheromones is firstly the type of vulcanization used for the manufacture of elastomers: that with sulfur, generating disulfide, induces a very high rate of isomerization while that with crosslinked phenolic resins urethanes or peroxides does not induce isomerization. Since pheromones are often a very expensive component of phytosanitary formulations for sexual confusion or other pest control techniques, it is advisable to optimize their stability during use to optimize their effectiveness which lies in their diffusion in the air.

[0015] When it comes to stabilizing these pheromones based on compounds comprising photosensitive conjugated unsaturated systems, those skilled in the art have used chemical stabilizers.

[0016] 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, it is the anti-UV compound Tinuvin® P of the benzotriazole type which is used at levels between 0.1% and 10% by weight relative to the weight of the pheromone.

[0017] In WQ2002 / 080672, the authors mix the pheromones with di-tert-butyl-2,2'-methylenedi-p-cresol (MBMBP) as an antioxidant and this mixture is used with any type of pheromone dispenser such as microcapsules (e.g., urea, gelatin, 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 inhibitors such as carbon blacks or titanium dioxide, but there are no specific examples to support this possibility, even less so in the context of the use of microcapsules. Indeed, since these mineral fillers have particle sizes in the micron range, their insertion into microcapsules of a similar size does not appear obvious.At best, one can envisage the simultaneous presence of pheromone microcapsules and carbon blacks or the use of other larger diffusion systems. However, the superposition of two populations of microcapsules, one containing the pheromone and the other containing the carbon black, cannot give the same stabilizing and protective effect as a single population of microcapsules containing in its core both the light-sensitive active principle (the pheromone) and its protective charge (the carbon black).

[0018] In WO2017 / 050956A1 and WO2016 / 131883A1, the applicant described a particular method for encapsulating pheromones having the particularity of not requiring chemical reactions to construct the microcapsules which are organized under the action of the forces of attraction and repulsion of the fatty components and water controlled by an additive of the HASE type (Hydrophobie Alkali Swellable Emulsion in English). In these applications, the stabilizers of the pheromones are chemical molecules soluble with the pheromone and remaining at the heart of the microcapsules. The stabilizing molecules are tert-butyl hydroquinone, propyl gallate, t-butyl-hydroxy anisole, p-methyl-hydroxy-benzoate, N,N-diethyl-toluamide, BHT, alpha-thioglycerin, nitroxides and alkoxyamines. These products are known antioxidants and anti-UV.The particle sizes obtained are in the order of 0.1 to 10 μm, so it is difficult to introduce carbon blacks that have similar dimensions.

[0019] 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.

[0020] Carbon blacks are produced industrially using various processes such as those described in patent US9574087. These powders are in the form of grouped primary particles, agglomerated in clusters. The size of the primary particles can be of the order of a few tens of nanometers while the agglomerates have sizes of the order of a micron. The properties conferred by carbon blacks on the materials in which they are dispersed are always linked to the state of dispersion of the carbon black in this material. The usual applications of carbon blacks are in the field of plastics (for example piping), elastomers (for example vehicle wheels), inks and varnishes, paints. In addition to mechanical properties, carbon blacks provide important electromagnetic properties (conductivity, absorption of radiation in a broad spectrum for example).The problem of dispersing carbon blacks is specific to each type of use because carbon blacks are both very hydrophobic and very poorly dispersible in low-polar organic media. The applicant has not found an example in the prior art making it possible to combine carbon blacks and pheromones effectively, and in particular in microencapsulated pheromone formulations comprising in their core capsules both the pheromone and the carbon black.

[0021] However, when it comes to stabilizing the stereochemistry of pheromones with conjugated systems such as pheromone compounds (I) to (IX), chemical antioxidants or UV stabilizers are not sufficient to maintain the correct isomerism when the pheromone dispensers are exposed to sunlight and the use of carbon blacks could provide an economical and effective solution to this problem.

[0022] A very illustrative case is that of compound (VI) for which commercial products must include opaque containers to preserve the molecule for several months in the fields. As an example, mention can be made of aerosol cans of the brands Semios or Suterra (cf. J. Beck, Journal of Agricultural and Food Chemistry, 2012, 60, 8090).

[0023] Another Suterra product, Check Mate F Now (EPA registration number: 56336-38), is a suspension of pheromone microcapsules in water containing 1.16% of compound (VI). This product covers a crop for only 30 days, which is less than the theoretical evaporation time of the compound, which translates to a loss of active ingredient through chemical degradation.

[0024] There is therefore still a need to propose new formulations of light-sensitive pheromone microcapsules that can protect these pheromones from the harmful effects of light and prolong the effectiveness of these formulations over time. It is also important that such microcapsule formulations remain usable in conventional spraying equipment used by farmers.

[0025] SUMMARY OF THE INVENTION

[0026] 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.

[0027] The use of microcapsules having a median diameter D50 ranging from 0.5 μm to 20 μm allows in particular their application by spraying, larger diameters risking clogging the nozzles of the spraying equipment conventionally used by farmers, thus preventing effective treatment of crop fields. Preferably, the microcapsules according to the invention comprise:

[0028] — a core comprising a mixture of wax, oil, pheromone (for example insect or mammalian pheromone), and carbon black particles, preferably the primary particles of which have a median diameter D50 ranging from 10 nm to 50 nm, the core being further able to comprise 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 thereof, and

[0029] — a solid outer shell surrounding the core, the shell comprising more particularly a HASE-type copolymer, optionally neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt.

[0030] Preferably, the carbon black particles consist of primary particles having a median diameter D50 ranging from 10nm to 50nm, in particular from 10nm to 40nm, for example from 11nm to 30nm, in particular from 12nm to 20nm.

[0031] The presence of carbon black particles in the microcapsules protects the pheromone also present in these microcapsules against 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, allowing for longer effectiveness.

[0032] However, if the primary carbon black particles can have a diameter much smaller than the size of these microcapsules such as a median diameter D50 of 10 nm to 50 nm, these primary particles agglomerate together and are therefore in the form of agglomerates having a diameter of the order of a micron or more, not allowing effective encapsulation of the carbon black in microcapsules having a diameter of the same order of magnitude.

[0033] It appears, in fact, and surprisingly, that the HASE-type copolymer used to prepare the shell of the microcapsules also makes it possible, during the microcapsule manufacturing process, to disperse the carbon black agglomerates so that the primary carbon black particles are no longer agglomerated with each other and can thus be integrated into microcapsules having a median diameter D50 of 0.5 pm to 20 pm. It seems in fact that the particular nature of the HASE-type copolymer, which combines both ionic functions and very hydrophobic functions, makes it possible to disperse the carbon black agglomerates due to the strong affinity of these two types of functionalities with carbon black. Thus, it is possible both to disperse the carbon black agglomerates and to integrate them, with the pheromone, into microcapsules having a median diameter D50 of 0.5 pm to 20 pm.

[0034] The present invention 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).

[0035] The present invention also relates to a method for manufacturing the microcapsules according to the invention. This method comprises mixing the ingredients forming the core of the microcapsules, namely in particular wax, oil, pheromone (for example insect or mammal pheromone), carbon black particles, and optional additive(s), forming the cores of the microcapsules from this mixture and coating them with the material constituting the outer shell, preferably a HASE-type copolymer. This method can implement any technique for forming microcapsules, i.e. depositing a shell around a core, known in the art.

[0036] When the outer shell comprises a HASE-type copolymer, said method advantageously comprises:

[0037] (a) preparing a fatty phase comprising wax, oil, pheromone (e.g. insect or mammalian pheromone), and carbon black particles, and optionally one or more additives when present, the fatty phase having a temperature above the melting temperature of the wax,

[0038] (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, in particular from 8 to 10, and a temperature substantially identical to that of the fatty phase,

[0039] (c) adding the fatty phase to the aqueous solution comprising the HASE-type copolymer, and stirring so as to form a dispersion of fatty phase droplets in the aqueous solution, and

[0040] (d) acidification to a pH of 6 to 7.5, preferably 6.5 to 7.2. DETAILED DESCRIPTION OF THE INVENTION

[0041] 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 they are exposed to light, typically during use in the field, thus increasing the duration of effectiveness of these active ingredients.

[0042] Microcapsules

[0043] 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.

[0044] For the purposes of the present invention, the term “median diameter D50” of microcapsules means the median diameter of a distribution of microcapsules, i.e. the diameter such that 50% of the microcapsules by volume have a diameter less than or equal to this value and that 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 device, in particular according to the method described in the experimental part.

[0045] The distribution of microcapsule sizes will be more particularly monomodal.

[0046] For the purposes of the present invention, the term "monomodal" means that the particle size curve of the microcapsules has a single peak. The particle size curve represents the volume percentage of the microcapsules as a function of their diameter and is determined by laser diffraction, in particular using a Mastersizer 3000 device, in particular according to the method described in the experimental section.

[0047] For the purposes of the present invention, the term "pheromone" means a chemical substance or a mixture of chemical substances emitted by an animal, or an analogue of such a chemical substance or such a mixture of chemical substances, and which represents a stimulus for individuals of this animal species. Such molecules can also stimulate individuals of other species, such as, for example, the territorial pheromone of a predator such as the fox, which can be perceived as a danger message by rodent species. Pheromones can be produced either by living organisms or by chemical synthesis. The pheromone is more particularly a chemical substance or a mixture of chemical substances emitted by an animal.

[0048] Preferably, the pheromones used in the context of the present invention carry a photosensitive function, such as one or more unsaturations, preferably conjugated unsaturations.

[0049] For the purposes of the present invention, the term "unsaturation" means a C=C double bond or a C=C triple bond.

[0050] For the purposes of the present invention, the term “conjugated unsaturations” means an unsaturation as defined above linked to another unsaturation as defined above by a single bond.

[0051] The pheromone will more particularly be an insect or mammalian pheromone or possibly an analogue thereof, such as a lepidopteran pheromone (such as a lepidopteran of the genus Lobesia, the codling moth, the tomato leaf miner (Tuta absolute / ), the horse chestnut leaf miner, the pine processionary moth, Amyelois transitella, Grapholita molesta, the date moth or the oak processionary moth), or an aphid pheromone, or possibly an analogue thereof, or a mixture thereof.

[0052] The pheromone may be a long-chain unsaturated lepidopteran pheromone, a terpene such as one of molecules (I) to (VI), (VIII), (IX), and (X) to (XII) above, a sesquiterpene such as molecule (VII) above, or a mixture thereof.

[0053] 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.

[0054] The carbon black particles consist of primary particles that can agglomerate with each other to form agglomerates. Preferably, the primary particles are not agglomerated or are weakly agglomerated in the microcapsules according to the invention. They are therefore preferably dispersed in the microcapsules.

[0055] 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 10 nm to 40 nm, for example from 11 nm to 30 nm, in particular from 12 nm to 20 nm.

[0056] For the purposes of the present invention, the term "median diameter D50" of the primary carbon black particles means the median diameter of a distribution of primary carbon black particles, i.e. 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. Qjan, Size and shape distributions of carbon black aggregates by transmission electron microscopy, Carbon (2018).

[0057] The carbon black particles may be synthetic, particularly obtained from acetylene, or may be obtained by grinding coal. Preferably, the carbon black is synthetic, allowing access to smaller primary particle sizes. Preferred carbon black particles are carbon black particles intended for applications in inks and surface coatings, such as Monarch® brand grades 430, 700, 800, 1100 and 1300 or Cabot Company's Emperor® brand grades 1200, 1600 and 1800 or Orion Specialty Carbon Blacks Company's Special Black, Printex®, Arosperse® and NIPex® brand grades.

[0058] 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.

[0059] Heart of microcapsules

[0060] The core of the microcapsules advantageously represents from 90% to 99.9% by weight of the weight of the microcapsules.

[0061] The core comprises a mixture of pheromone (e.g. insect or mammal) and carbon black particles, and advantageously a wax and an oil.

[0062] Preferably, the core comprises, in particular is constituted by, a mixture of wax, oil, pheromone (for example insect or mammalian), 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 thereof. Preferably, the core comprises a dispersing additive, preferably non-ionic.

[0063] The heart will advantageously contain, in relation to the weight of the heart:

[0064] — 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 (for example insect or mammal),

[0065] — from 0.01% to 10%, preferably from 0.1% to 5%, by weight of the carbon black particles, from 0.5% to 50%, in particular from 0.5% to 30%, in particular from 1% to 25%, preferably from

[0066] 1 to 20%, by weight of wax, and from 20 to 95%, in particular from 30 to 90%, preferably 40 to 80%, by weight of oil.

[0067] The heart will preferably contain, in relation to the weight of the heart:

[0068] — 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 (for example insect or mammal),

[0069] — from 0.01% to 10%, preferably from 0.1% to 5%, by weight of the carbon black particles,

[0070] — 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,

[0071] — from 20% to 95%, in particular from 30% to 90%, preferably from 40% to 80%, by weight of oil, and

[0072] — up to 10% (eg 0.01% to 10%), in particular up to 5%, preferably from 0.1% to 5%, by weight of a dispersing additive, preferably non-ionic, of the carbon black particles relative to the weight of the core.

[0073] Preferably, the dispersing additive, preferably non-ionic, of the carbon black particles is present in the core in a weight amount less than or equal to that of the carbon black particles.

[0074] In particular, the core may contain up to 10% (eg 0.01% to 10%), in particular up to 5%, preferably 0.1% to 5%, of one or more additives.

[0075] For the purposes of the present invention, the term "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 temperature above 45°C at atmospheric pressure.

[0076] The waxes that may be used in a composition according to the invention may be chosen from waxes of animal origin, waxes of vegetable origin, mineral waxes, synthetic waxes and mixtures thereof. As wax of animal origin, mention may be made of beeswax, lanolin wax, or Chinese insect wax. As wax of vegetable origin, mention may be made of rice wax, carnauba wax, candelilla wax, jojoba wax, ouricurry wax, alfa wax, cork fiber wax, sugar cane wax, Japanese wax, or sumac wax. As mineral wax, mention may be made of montan wax, microcrystalline waxes, paraffins, or ozokerite. Examples of synthetic waxes include polyethylene waxes, waxes obtained by Fisher-Tropsch synthesis, or waxy copolymers and their esters.Hydrogenated derivatives of the waxes mentioned above may also be used as waxes in the context of the present invention. Mention may also be made of waxes obtained by catalytic hydrogenation of oils of animal or vegetable origin having unsaturated, linear or branched, C8-C32 fatty chains. Among these, mention may in particular be made of hydrogenated jojoba oil, hydrogenated sunflower oil, hydrogenated castor oil, hydrogenated coconut oil, or even hydrogenated lanolin oil, as well as di-(trimethylol-1,1,1-propane) tetrastearate. Waxes obtained by transesterification and hydrogenation of oils of plant origin, such as castor or olive oil, can also be used, such as the waxes sold under the names Phytowax ricin 16L64®, Phytowax ricin 22L73® and Phytowax Olive 18L57® by the company SOPHIM.

[0077] Advantageously, the wax is selected from the group consisting of beeswax, lanolin wax, Chinese insect wax, rice wax, carnauba wax, candelilla wax, jojoba wax, ouricurry wax, alfa wax, cork fiber wax, sugarcane wax, Japanese wax, sumac wax, montan wax, microcrystalline waxes, and mixtures thereof.

[0078] For the purposes of the present invention, the term "oil" means a fatty compound, liquid at room temperature and atmospheric pressure, immiscible with water and non-volatile.

[0079] The oil according to the invention may be chosen from oils of vegetable origin, oils of animal origin, synthetic oils, and mixtures thereof; preferably chosen from oils of vegetable origin, oils of animal origin, and mixtures thereof. The oil of vegetable origin 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. Animal oil will be advantageously chosen from the group consisting of cod liver oil, shark oil and their mixtures.

[0080] 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 thereof. The dispersing additive, preferably non-ionic, of the carbon black particles may be Disperbyk® 163 from the company Byk Chemie or the product Borchi® Gen 0451 from the company Borchers. Such dispersants may be prepared according to EP2091984 or EP2125909, the teaching of which is incorporated by reference concerning the compositions and copolymers useful as dispersing agents.

[0081] Anti-UV additives or antioxidants well known to those skilled in the art may be added to limit the oxidation reactions caused by oxygen at 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-B^S'-tertamylphenyl)benzotriazole, or 2-(2'-hydroxy-3'-tert-butyl-5'-methyl-phenyl)-5-chlorobenzotriazole), propyl gallate, or derivatives of 4-tetramethyl-piperidine, in particular 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 reported in FR2788272).

[0082] Microcapsule envelope

[0083] The envelope will advantageously comprise a HASE type copolymer, optionally neutralized, totally or partially, in the form of a sodium, potassium or ammonium salt.

[0084] For the purposes of the present invention, the term "HASE-type copolymer" (HASE being the abbreviation for "Hydrophobically modified Alkali Swellable Emulsion") 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:

[0085] [Chem. A] in which:

[0086] — m is an integer greater than or equal to 5, preferably between 10 and 30, and — R a hydrocarbon group of formula C n H2n+i in which n is an integer between

[0087] 9 and 25, preferably between 10 and 22 and even more preferably equal to 12, 16 or 22. The R group is therefore hydrophobic

[0088] By "neutralized, totally or partially", is meant, for the purposes of the present invention, that all or part of the carboxylic acid functions (COOH) carried by the HASE type copolymer are in salt form, and more particularly in the form of sodium, potassium or ammonium salt.

[0089] Advantageously, the HASE type copolymer comprises, in particular is made up of, relative to the total weight of the copolymer:

[0090] — between 30% and 40% by weight of repeating units derived from methacrylic acid,

[0091] — between 45% and 60% by weight of repeating units derived from ethyl acrylate, and

[0092] — between 5% and 20% by weight of repeating units derived from a macromonomer of the following Chem. A formula:

[0093] [Chem. A] in which:

[0094] • m is an integer greater than or equal to 5, preferably between 10 and 30, and

[0095] • R a hydrocarbon group of formula C n H2n+i in which n is an integer between 9 and 25, preferably between 10 and 22 and even more preferably equal to 12.

[0096] The HASE-type copolymer can be prepared, for example, according to one of the methods described in WO2011 / 104599, WO2011 / 104600 and EP1778797. It can be Pharma 38 or Viscoatex 730LV from Coatex.

[0097] Manufacturing process

[0098] The microcapsules according to the invention can be prepared according to the method 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. The fatty 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 thereof) having the composition of the core described above.

[0099] The fatty phase is maintained, preferably with stirring, at a temperature above the melting temperature of the wax so as to be liquid. In a particular embodiment, the fatty phase is at a temperature of 50°C to 85°C, in particular 60°C to 80°C.

[0100] Advantageously, the fatty phase is prepared by mixing the oil and the additive(s) (in particular the dispersing additive, preferably non-ionic, of the 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.

[0101] 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 will advantageously be chosen from sodium or potassium carbonate, ammonium hydroxide or ammonia in aqueous solution, sodium hydroxide, potassium hydroxide and combinations thereof.

[0102] 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. The concentration of HASE-type copolymer in the aqueous solution makes it possible to influence the size of the final microcapsules. Indeed, the size of the final microcapsules decreases when the concentration of HASE-type copolymer increases.

[0103] This aqueous solution is then heated to a temperature substantially identical to that of the fatty phase.

[0104] By "temperature substantially identical" to that of the fatty phase, we advantageously mean a temperature not varying by more than 10°C, in particular by more than 5°C, compared to the temperature of step (a). Preferably, the temperature of step (b) will be identical to that of step (a). Thus, the aqueous solution is advantageously at a temperature of 50°C to 85°C, in particular of 60°C to 80°C.

[0105] In this step, the fatty phase having the temperature of step (a) is added to the aqueous solution having the temperature of step (b).

[0106] The mixture is then stirred to form a dispersion of fatty phase droplets in the aqueous solution. The fatty phase droplets formed in the aqueous solution will form the core of the microcapsules.

[0107] Acidification allows the HASE-type copolymer present in the aqueous solution to precipitate onto the droplets, which then become microcapsules comprising the core based on the fatty phase surrounded by the solid shell based on the HASE-type copolymer. These particles are dispersed in water and thus form an aqueous suspension of the microcapsules.

[0108] In a particular embodiment, the 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 thereof, 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.

[0109] The temperature of the aqueous suspension of 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.

[0110] According to a particular embodiment, the method implements the steps below.

[0111] First step (step (a)): In a mixer equipped with a heating system and mechanical agitation, the oil and the additive(s), such as the dispersing additive, preferably non-ionic, of the carbon black particles, are mixed and brought to a temperature above the melting temperature of the wax, then the 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 an amount Q, and the HASE-type copolymer, preferably in an amount of 0.1% to 10% w / w, in particular 0.1% to 5% w / w, preferably 0.1% to 1% w / w, are mixed, 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 of the first step.

[0112] Third step (step (c)): The mixture from the first step (fat phase) is added to the aqueous phase with stirring to form droplets. When the addition is complete, stirring can be continued, for example for 10 minutes to 2 hours.

[0113] Fourth step (step (d)): The pH is brought to a value of 6 to 7.5, preferably 6.5 to 7.2, by means of an acid solution, such as phosphoric acid, sulfuric acid or hydrochloric acid, in particular at a concentration of 2 to 10% by weight. The acidification allows the coalescence of the HASE-type copolymer on the surface of the droplets, thus forming the solid shell around the cores of the microcapsules. The resulting aqueous suspension of the microcapsules is then brought to room temperature, optionally with stirring.

[0114] Use

[0115] The present invention also relates to the use of the microcapsules according to the invention for protecting a plant (in particular a crop) or a harvest against insects or mammals, in particular when said plant or harvest is exposed to light, for example solar or artificial light.

[0116] Pheromones will influence the behavior of animals such as insects (e.g., lepidoptera or aphids), rodents, or even game (e.g., roe deer, red deer, fallow deer, wild boar) responsible for damage to plants (especially crops) and crops. The pheromone(s) will be chosen according to the animal (e.g., the insect or mammal) against which the plant or crop is to be protected. For example, the pheromone may be chosen to lure a lepidoptera according to a trapping protocol or according to a mating disruption protocol. The microcapsules according to the invention, more particularly in the form of an aqueous suspension, may be applied using techniques known to those skilled in the art to supports present in the storage location (walls, posts, floors, etc.) or to bags containing the seeds.

[0117] In the case of plant protection, microcapsules, particularly in the form of an aqueous suspension, can be applied to plants, particularly their foliage, for example using a spraying system.

[0118] 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).

[0119] Preferably, the plants to be protected are vines, field crops (rice, corn, cotton, soybeans, sunflowers, etc.), market garden crops (tomatoes, lettuce, 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.).

[0120] The crops to be protected will be more particularly seeds such as wheat, corn, etc. These seeds will need to be protected during storage.

[0121] FIGURES

[0122] Figure 1: Photograph obtained by optical microscopy of the microcapsules obtained in example 1.

[0123] Figure 2: monitoring of the release over time of the pheromone (I) encapsulated in microcapsules with black particles placed in an oven at 30°C.

[0124] Figure 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).

[0125] Figure 4: Particle size curve of the microcapsules of examples 2a and 2b.

[0126] Figure 5: Photograph obtained by optical microscopy of the microcapsules obtained in example 3.

[0127] Figure 6: Photograph of the test tubes of examples 4a (tube a), 4b (tube b) and 4c (tube c) obtained after 5 min under ultrasound.

[0128] Figure 7: Photograph of the microcapsule suspension from counterexample 5. Figure 8: Particle size curve of the microcapsules from counterexample 7.

[0129] EXAMPLES

[0130] 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 supplied commercially by the company Coatex. The carbon black particles used in the examples are synthetic carbon black particles obtained from acetylene and consisting of primary particles having a median diameter D50 of 14 to 20 nm but whose aggregates have a size of the order of 100 microns.

[0131] The size of the microcapsules is measured by light diffraction analysis with a Mastersizer 3000 device by laser beam diffraction. The measurement protocol is as follows: First, the samples are prepared by dispersing 0.5g of formulation in 100ml of demineralized water under magnetic stirring for 10 min. Then, the particle sizes are measured, taking care first to align the device and to measure the background noise to record the diffraction phenomena generated by the water. The sample is then introduced into the measuring cell and 5 successive measurements are carried out. These measurements make it possible to establish a particle size curve from which the median diameter D50 is determined. The particle size is then determined by taking the average of these 5 measurements.

[0132] Analysis of pheromone levels is performed by gas chromatography (GC) with a flame ionization detector on an Agilent - HP Series II 5890 instrument.

[0133] Pheromone release studies are carried out in ventilated ovens without a window so as not to be exposed to light radiation. These studies are carried out using two methods, either by monitoring the weight loss of the samples or by monitoring the residual concentration of the pheromone in the sample by GC.

[0134] Accelerated light aging studies to study photochemical degradation (e.g. isomerization) are carried out in daylight or in the laboratory using a tabletop solar simulator, the Solartest 1200.

[0135] Optical microscopy is performed on a ZEISS AXIO PLAN 2 microscope. Sample observations are performed in transmission with a 40x plan and 20x plan objective. A ZEISS AxioCam ICC3 camera allows images to be viewed on a computer screen. For example 8b, the Grapholita molesta pheromone mixture was used. This mixture is composed of the following two molecules (VIII) and (IX) in a 15 / 85 ratio:

[0136] [Chem. (VIII)]

[0137] Example 1: Microcapsules with pheromone (I)

[0138] In a 500 mL jacketed glass reactor, equipped with mechanical stirring, 200 g of sunflower oil are introduced, then 2 g of Disperbyk® 163 (additive dispersing carbon black particles). The mixture is brought to a temperature of 80°C, then 90 g of purified beeswax are added. Once returned to 80°C, 2 g of Emperor® 1200 carbon black particles are added. After a few seconds, the mixture becomes homogeneously black and 15 g of pheromone (I) are then added. The core formulation is left stirring while the shell formulation is prepared.

[0139] In a double jacketed IL reactor, equipped with a magnetic stirrer, 307 mL of deionized water are added, then 9.6 g of Viscoatex 730LV (i.e. 3.2 g of dry matter). A 10% sodium hydroxide solution is then poured in drop by drop to reach a pH of 8.5. 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 brought to 80°C.

[0140] Using a peristaltic pump, the core formulation is transferred into the IL reactor at a flow rate of 5 mL per minute. To prevent the oil phase from freezing in the transfer pipes, they are immersed in a water bath at 80°C.

[0141] The viscosity of the medium gradually increases. At the end of the addition, stirring is continued for an additional hour, stopping the heating. When the temperature reaches 60°C, 11 mL of a 4% by weight phosphoric acid solution is added with vigorous stirring. The formulation becomes fluid and reaches a pH of 6.7. Once the mixture has returned to room temperature, a suspension of gray microcapsules is recovered. Characteristics obtained:

[0142] Dry extract: 48%

[0143] Encapsulation rate T: 99.7%

[0144] T = (amount of (I) total - amount of (I) in water) / amount of (I) total

[0145] Median diameter D50: 7 pm - Monomodal dispersion (no traces of carbon black agglomerates)

[0146] Characterization by microscopy: see photo in Figure 1

[0147] This photo shows that the carbon black particles are inside the microcapsules.

[0148] Release of the pheromone in an oven at 30°C:

[0149] 2 g of the microcapsule suspension are placed in plastic cups and placed in an incubator. The study TO takes place 24 hours after this incubator. A cup is then analyzed regularly by measuring its weight and by GC analysis to estimate the release of the pheromone under these conditions. For an 80-day study, a cup is taken at D3, D7, D12, D20, D31, D40, D60 and D80.

[0150] The results obtained are presented in Figure 2. A controlled release is observed over several weeks. Thus, the presence of carbon black particles in the microcapsules does not in any way hinder the encapsulation and prolonged release of the pheromone.

[0151] Monitoring the isomeric ratio over time:

[0152] The results obtained are presented in Figure 3. The measurements show that the isomerization of the pheromone (I) is less rapid 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.

[0153] Example 2: Microcapsules with pheromone (I)

[0154] In a 250 mL jacketed glass reactor equipped with an ultra-turrax™ T18 homogenizer, 5.5 g of sunflower oil are introduced, followed by 0.08 g of Emperor® 1200 (Example 2a) or Emperor® 1600 (Example 2b) carbon black. The mixture is stirred vigorously at 14,000 rpm for 1 h to thoroughly disperse the carbon black particles in the oil.

[0155] This mixture is then brought to a temperature of 80°C, then 18.6g of purified beeswax, 1.7g of BHT and 0.7g of oxybenzone are added. Once the mixture has returned to 80°C, 6.8g of pheromone (I) are then added. The core formulation is left stirring while the shell formulation is prepared.

[0156] In a 500mL jacketed reactor, equipped with an IKA mechanical stirrer set at 350 rpm, 158 mL of deionized water are added, then 8.8g of Pharma 38 (i.e. 2.6g of dry matter). A 10% sodium hydroxide solution is then poured dropwise to reach a pH of 10. This corresponds to a mass of 4.9g of sodium hydroxide solution under stirring. The formulation becomes thick and translucent with bluish reflections. The temperature of the solution is then brought to 80°C.

[0157] Using a peristaltic pump, the core formulation is transferred into the IL reactor at a flow rate of 5 mL per minute. To prevent the oil phase from freezing in the transfer pipes, they are immersed in a water bath at 80°C.

[0158] The viscosity of the medium gradually increases. At the end of the addition, stirring is continued for an additional hour. 4.5g of a 4% by weight phosphoric acid solution is then added with vigorous stirring. The formulation becomes fluid and reaches a pH of 6.8. The medium is allowed to naturally return to room temperature. A suspension of gray microcapsules is then recovered. The characteristics of the microcapsules thus obtained are presented in Table 2 below. In addition, the particle size curve of the microcapsules is presented in Figure 4.

[0159] [Table 2]

[0160] Example 3: Pheromone VI microcapsules

[0161] In a melter equipped with a turbine-type stirrer, 2.24 kg of sunflower oil are introduced followed by 3.6 g of carbon black. The mixture is stirred vigorously at 150 rpm for 40 minutes to thoroughly disperse the carbon black particles in the oil. This mixture is then brought to a temperature of 80°C, then 900 g of purified beeswax, 85 g of BHT and 52 g of Tinuvin® 571 are added. Once returned to 80°C, 127 g of pheromone (VI) are then added. The core formulation is left stirring while the shell formulation is prepared.

[0162] In a 15L unit equipped with a fixed speed blade and scraper agitation and a variable speed homogenizer, 8.29 kg of deionized water are added, then 110 g of Viscoatex 730LV (i.e. 33 g of dry matter). A 10% sodium hydroxide solution is then poured in drop by drop to reach a pH of 10. This corresponds to a mass of 69 g of sodium hydroxide solution under agitation. The formulation becomes thick and translucent with bluish reflections. The temperature of the solution is then brought to 80 ° C.

[0163] Using a peristaltic pump, the core formulation is transferred into the 15L reactor (homogenizer set at 4000 rpm) at a flow rate of 50kg / h. The viscosity of the medium gradually increases. At the end of the addition, stirring is continued for a further 20 minutes. Still at a speed of 4000 rpm, 123g of a 4% by weight phosphoric acid solution is then added. The formulation becomes fluid and reaches a pH of 6.7. After 25 minutes of stirring at 4000 rpm, a suspension of gray microcapsules is recovered.

[0164] Characteristics obtained:

[0165] Median diameter D50 = 4.63pm - Monomodal distribution

[0166] Encapsulation efficiency = 100%

[0167] Characterization by microscopy: see photo in Figure 5

[0168] The photo in Figure 5 shows that the carbon black particles are inside the microcapsules, and more particularly at the periphery of the microcapsules, which suggests that the HASE-type copolymer shell (Viscoatex 730LV) plays an important role in the incorporation of the elementary carbon black particles into the pheromone microcapsules.

[0169] Example 4 (outside the invention): importance of oil and HASE-type copolymer for dispersing carbon black particles

[0170] Carbon black dispersion tests were carried out in water, a 30% by weight aqueous solution of Pharma 38 and in oil. The carbon black and then the dispersion medium under study were loaded into a test tube. The whole was placed under ultrasound for 5 minutes. The tests carried out are presented in Table 3 below.

[0171] [Table 3]

[0172] An observation of the suspension obtained is then carried out (see Figure 6). The following results were obtained showing: example 4a: a very poor dispersion of carbon black in water is observed: the carbon black particles instantly rise to the surface leaving the aqueous phase perfectly colorless; example 4b: a good dispersion of carbon black in the Pharma 38 solution is observed: the carbon black particles remain well suspended in the medium after 18 hours of standing; example 4c: a good dispersion of carbon black in sunflower oil is observed; the carbon black suspension does not evolve after 18 hours without stirring.

[0173] This example outside the invention makes it possible to show that the use of HASE type copolymer and oil contributes to the homogeneous dispersion of the carbon black and conditions the obtaining of a monomodal distribution of the microcapsules according to the invention.

[0174] Furthermore, the fact that Figure 5 shows a distribution of carbon black on the surface of the microcapsules demonstrates the predominant role of the HASE-type copolymer which constitutes the envelope of the microcapsules.

[0175] Example 5 (counter-example outside the invention): Pheromone I microcapsules containing vegetable carbon black The microcapsules of this example were prepared according to the procedure described in Example 2 by replacing the Emperor® 1200 or 1600 carbon black with vegetable carbon black which does not aggregate but whose primary particle sizes are greater than 10 microns.

[0176] Results :

[0177] The appearance of the microcapsule suspension is white with black dots visible to the naked eye (Figure 7). The particle size curve of these microcapsules is presented in Figure 8 and shows a bimodal particle size profile.

[0178] The particle size profile of these microcapsules shows that, during the microcapsule manufacturing process, the carbon black particles were not reduced in size by the process, which prevents their integration into the microcapsules, resulting in two types of particles. The particle size profile of such a microcapsule suspension prevents its use by spraying. In addition, the segregation of the carbon black particles suggests that it will not be able to play its protective role against the pheromone present in the microcapsules.

[0179] In particular, this counterexample illustrates that the choice of carbon black particles having primary particle sizes that are too large does not allow homogeneous dispersions to be obtained.

[0180] Example 6 (counter-example outside the invention): Test of formation of pheromone VI microcapsules by introducing carbon black in step b)

[0181] The microcapsules of this example were prepared according to the procedure described in Example 1 using the ingredients mentioned in Table 4 below and introducing the carbon black into the aqueous phase containing the HASE-type copolymer.

[0182] [Table 4]

[0183] In this test, the formulation demixed during the acidification phase. This counterexample demonstrates the importance of the order of introduction of the materials to ensure good stability of the pheromone and carbon black microcapsules. This counterexample also demonstrates that the method according to the invention is essential to obtain a stable, homogeneous and monomodal dispersion of pheromone and carbon black particles.

[0184] Example 7: Microcapsules with pheromone (VI) and different contents of carbon black particles The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients mentioned in Table 5 below (the additive(s) being added just after the oil).

[0185] [Table 5]

[0186] The encapsulation yields obtained with the three formulations 7a to 7c are presented in Table 6 below. They show that the presence of carbon black particles in the microcapsule, whatever their content, does not alter the encapsulation of the pheromone in the microcapsules.

[0187] [Table 6]

[0188] Example 8: Microcapsules with different pheromones and different formulations

[0189] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients listed in Table 7 below (with the additive(s) being added just after the oil).

[0190] [Table 7]

[0191] The encapsulation yields obtained with the four formulations 8a to 8d are presented in Table 8 below. These yields are very good regardless of the formulation. [Table 8]

[0192] Example 9: Pheromone microcapsules (VI) with different encapsulating polymers

[0193] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients listed in Table 9 below (with the additive(s) being added just after the oil). [Table 9]

[0194] This example shows that different HASE-type copolymers can be used to manufacture pheromone microcapsules according to the invention comprising carbon black particles.

[0195] Example 10: Effect of carbon black particles in pheromone protection

[0196] Pheromone (VI)-based microcapsules and various anti-UV additives instead of carbon black particles were prepared according to the method of Example 1 using the ingredients mentioned in Table 10 below (the additive(s) being added just after the oil).

[0197] [Table 10]

[0198] * comparative examples

[0199] The pheromone (VI) is very fragile and rearranges very easily into the E,Z isomer under the effect of visible light. After exposing the microcapsules of examples 10a to 10d to daylight on cardboard plates, the change in the concentration of the different isomers remaining in the microcapsules is measured. The results obtained are presented in Table 11 below.

[0200] [Table 11]

[0201] These results show a better stability (preservation of the initial isomeric ratio) of the active ingredient studied, namely the 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 for a 2 to 4 times lower content of additive 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 other microcapsules.

[0202] Example 11: Pheromone (VI) microcapsules with high carbon black particle content

[0203] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients listed in Table 12 below. [Table 12]

[0204] Example 12: Microcapsules with low concentrations of pheromones (III), (IV) and (XI) for diffusers for trapping tomato and horse chestnut leaf miners and oak processionary moths

[0205] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients listed in Table 13 below.

[0206] [Table 13]

[0207] These three formulations have an encapsulation rate greater than 99%.

[0208] Example 13: Microcapsules of pheromones (X) and (XII) for diffusers to combat the date moth

[0209] The microcapsules in this example were prepared according to the procedure described in Example 1 using the ingredients listed in Table 14 below.

[0210] [Table 14]

[0211] Both formulations have an encapsulation rate greater than 99%.

Claims

CLAIMS Microcapsules having a median diameter D50 ranging from 0.5 pm to 20 pm, preferably from 1 pm to 10 pm, comprising: - a core comprising a mixture of wax, oil, pheromone, and carbon black particles, the carbon black particles being composed of primary particles having a median diameter D50 ranging from 1 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. Microcapsules according to claim 1, characterized in that the carbon black particles consist of primary particles having a median diameter D50 ranging from 11 nm to 40 nm, for example from 11 nm to 30 nm, in particular from 12 nm to 20 nm. 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. 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.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. (Ill)] [Chem. (XI)] 6. 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%, especially 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%, especially 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. Use of microcapsules according to any one of claims 1 to 11, for the protection of a plant or crop against insects or mammals, particularly when said plant or crop is exposed to light. Method for manufacturing microcapsules according to any one of claims 1 to 11 including: (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 from 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) adding the oil phase to the aqueous solution comprising the HASE-type copolymer and stirring 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. A process according to claim 13, characterized in that the temperature at step (a) and 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.

Images