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US-20260123625-A1 - AGROCHEMICAL COMPOSITION FOR SEED COATING

US20260123625A1US 20260123625 A1US20260123625 A1US 20260123625A1US-20260123625-A1

Abstract

The present invention relates to a composition comprising particles suspended in an aqueous phase, wherein: said particles comprise a solid shell surrounding a core, wherein: —the solid shell comprises at least one HASE-type copolymer, and —the core represents at least 90 wt. %, in particular from 90 to 99.5 wt. %, of the total weight of the particles and comprises a mixture of wax, oil and a semiochemical compound, the aqueous phase comprises at least one ASE-type copolymer and a base selected from ammonium hydroxide, sodium hydroxide, potassium hydroxide and combinations thereof, so that the aqueous phase has a pH of between 7 and 9.5, preferably between 7 and 8. The present invention also relates to a kit comprising: —a first, in particular agrochemical, composition comprising particles suspended in an aqueous phase, wherein: said particles comprise a solid shell surrounding a core, wherein: —the solid shell comprises at least one HASE-type copolymer, and —the core represents at least 90 wt. %, in particular from 90 to 99.5 wt. %, of the total weight of the particles and comprises a mixture of wax, oil and a semiochemical compound, and —a second composition comprising, in an aqueous phase, at least one ASE-type copolymer and a base selected from ammonium hydroxide, sodium hydroxide, potassium hydroxide and combinations thereof, so that the aqueous phase has a pH of between 7 and 9.5, preferably between 7 and 8. The present invention also relates to a method for preparing this composition, to a method for treating a seed with such a composition or such a kit, to the seed thus treated and to the use of this composition or of this kit to protect a seed, more particularly which is intended to be sown, and/or an emerging seedling from an insect or nematode pest.

Inventors

  • Yannick ESCUDIE
  • Tanguy SORLIN
  • Olivier Guerret

Assignees

  • MELCHIOR MATERIAL AND LIFE SCIENCE FRANCE

Dates

Publication Date
20260507
Application Date
20221221
Priority Date
20211221

Claims (20)

  1. 1 . A composition comprising particles suspended in an aqueous phase, wherein: the particles comprise a solid envelope surrounding a core, wherein: the solid envelope comprises at least one HASE copolymer, and the core represents at least 90% by weight of the total weight of the particles and comprises a mixture of wax, oil and a semiochemical compound, wherein the aqueous phase comprises at least one ASE copolymer and a base selected from ammonium hydroxide, sodium hydroxide, potassium hydroxide and combinations thereof, so that the aqueous phase has a pH of from 7 to 9.5.
  2. 2 . A kit comprising: a first composition comprising particles suspended in a first aqueous phase, wherein: the particles comprise a solid envelope surrounding a core, wherein: the solid envelope comprises at least one HASE copolymer, and the core represents at least 90% by weight of the total weight of the particles and comprises a mixture of wax, oil and a semiochemical compound, and a second composition comprising, in a second aqueous phase, at least one ASE copolymer and a base selected from ammonium hydroxide, sodium hydroxide, potassium hydroxide and combinations thereof, so that the second_aqueous phase has a pH of from 7 to 9.5.
  3. 3 . The composition according to claim 1 , wherein the HASE copolymer contains, based on the total weight of the copolymer: from 30% to 40% by weight of repeating units derived from methacrylic acid, from 45% to 60% by weight of repeating units derived from ethyl acrylate, and from 5% to 20% by weight of repeating units derived from a macromonomer of the formula Chem. I: where m is an integer from 1 to 40, and R is a hydrocarbon group of formula C n H 2n+1 in which n is an integer from 9 to 25.
  4. 4 . The composition according to claim 1 , wherein the ASE copolymer contains, based on the total weight of the copolymer: from 20% to 60% by weight of repeating units derived from metacrylic acid, and from 40% to 80% by weight of repeating units derived from ethyl acrylate.
  5. 5 . The composition according to claim 1 , wherein the core of the particles contains, based on the total weight of the core: from 25% to 90% by weight of oil, from 8% to 50% by weight of wax, and from 0.1% to 25% by weight of semiochemical compound.
  6. 6 . The composition according to claim 1 , wherein: 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, esparto wax, cork fiber wax, sugar cane wax, Japan wax, sumac wax, montan wax, microcrystalline waxes, and mixtures thereof; and/or the oil is selected 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.
  7. 7 . (canceled)
  8. 8 . The composition according to claim 1 , wherein the semiochemical compound is selected from thymol, geraniol, alpha-pinene, beta-pinene, limonene, camphor, camphene, sabinene, menthol, eucalyptol, β-caryophyllene, β-ocimenes, citronellol, linalool and its acetate, lavandulyl acetate, terpineols, terpinenes, Z-11-hexadecenal, Z-9-tetradecenal, n-hexanal, 3-hexenal, octanal, 2-hexenyl acetate, octenyl acetate, hexadienyl acetate, jasmone, methyl jasmonate, er and a mixture thereof.
  9. 9 . A method of preparing a composition according to claim 1 , comprising the following steps: (i) preparing an aqueous suspension of the particles; (ii) adding the at least one ASE copolymer; and (iii) adding the base so as to obtain a pH from 7 and to 9.5.
  10. 10 . The method according to claim 9 , wherein the base of step (iii) is selected from ammonium hydroxide, sodium hydroxide, potassium hydroxide and combinations thereof.
  11. 11 . The method according to claim 9 , wherein step (i) comprises the following steps: (a) preparing a fatty phase comprising the wax, the oil and the semiochemical compound, (b) heating the fatty phase at a temperature above the melting point of the wax to obtain a heated fatty phase, (c) preparing an aqueous solution comprising the HASE copolymer, the aqueous solution comprising the HASE copolymer having a pH from 8 to 10, (d) heating the aqueous solution comprising the HASE copolymer at a temperature substantially identical to that of the fatty phase to obtain a heated aqueous solution comprising the HASE copolymer, (e) adding the heated fatty phase to the heated aqueous solution comprising the HASE copolymer and stirring so as to form a dispersion of fatty phase droplets in the aqueous solution, and (f) acidifying at a pH from 6 to 7.5, to form the particles, wherein step (f) can be concomitant with step (ii).
  12. 12 . A method of treating a seed comprising: the application of a composition comprising particles suspended in an aqueous phase to a seed, wherein the particles comprise a solid envelope surrounding a core, wherein: the solid envelope comprises at least one HASE copolymer, and the core represents at least 90% by weight of the total weight of the particles and comprises a mixture of wax, oil and a semiochemical compound, wherein the aqueous phase comprises at least one ASE copolymer and a base selected from ammonium hydroxide, sodium hydroxide, potassium hydroxide and combinations thereof, so that the aqueous phase has a pH of from 7 to 9.5, or the application of a first composition to a seed; then the application, in one or more times, of a second composition to the seed previously covered with the first composition of the kit, wherein: the first composition comprises, in a first aqueous phase, at least one ASE copolymer and a base selected from ammonium hydroxide, sodium hydroxide, potassium hydroxide and combinations thereof, so that the first aqueous phase has a pH of from 7 to 9.5, and the second composition comprises particles suspended in a second aqueous phase, the particles comprise a solid envelope surrounding a core, wherein: the solid envelope comprises at least one HASE copolymer, and the core represents at least 90% by weight of the total weight of the particles and comprises a mixture of wax, oil and a semiochemical compound.
  13. 13 . The method according to claim 12 , wherein the seed is further treated with a composition other than the compositions of claim 12 .
  14. 14 . A seed coated with the composition of claim 1 .
  15. 15 . The seed coated according to claim 14 , wherein the seed is selected among cereal seeds, seeds of protein-oleaginous plants.
  16. 16 .- 18 . (canceled)
  17. 19 . The kit according to claim 2 , wherein the HASE copolymer contains, based on the total weight of the copolymer: from 30% to 40% by weight of repeating units derived from methacrylic acid, from 45% to 60% by weight of repeating units derived from ethyl acrylate, and from 5% to 20% by weight of repeating units derived from a macromonomer of the formula Chem. I: where m is an integer from 1 to 40, and R is a hydrocarbon group of formula C n H 2n+1 in which n is an integer from 9 to 25.
  18. 20 . The kit according to claim 2 , wherein the ASE copolymer contains, based on the total weight of the copolymer: from 20% to 60% by weight of repeating units derived from metacrylic acid, and from 40% to 80% by weight of repeating units derived from ethyl acrylate.
  19. 21 . The kit according to claim 2 , wherein the core of the particles contains, based on the total weight of the core: from 25% to 90% by weight of oil, from 8% to 50% by weight of wax, and from 0.1% to 25% by weight of semiochemical compound.
  20. 22 . The kit according to claim 2 , wherein: 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, esparto wax, cork fiber wax, sugar cane wax, Japan wax, sumac wax, montan wax, microcrystalline waxes, and mixtures thereof; and/or the oil is selected 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.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to compositions and kits, in particular agrochemical compositions, comprising a semiochemical compound, and more particularly a repellent compound against pest insects or nematodes, intended to treat seeds in order to protect them against pest insects or nematodes. Indeed, the compositions and kits according to the invention allow to protect the crops from sowing to emergence of the plant, by diffusing in the soil, in a prolonged way, a semiochemical compound to which pest insects and nematodes present in the soil are sensitive. STATE OF THE ART Many technologies are currently used to treat seeds with the purpose of improving crop performances, for example by stimulating plant growth or by protecting seeds from harmful and undesirable organisms, such as pest insects or nematodes. A range of fungicide treatments using liquids and/or slurries have long been used to control soil-borne diseases in seeds. Recent developments in seed treatments have focused on the use of techniques to deliver pesticides, particularly insecticides, to the seeds, notably via the technique of seed coating. One of the problems encountered with seed coating is the phytotoxic effect of the active ingredients contained in the coating. In the past, the concentration of the active ingredients in the seed coating was limited. Now, the coating itself is used to protect the seed from the phytotoxicity of active ingredients, such as insecticides. U.S. Pat. No. 7,836,630 describes a coating method using a polymer to form a tight barrier between the seed and the active ingredient that is phytotoxic. Many polymers are mentioned, including, among others, natural polysaccharides, cellulose derivatives, or more classical polymers such as polyacrylic acid derivatives or PVA. This document describes a coating formed in two steps by applying an insulating layer devoid of any active ingredient around the seed, followed by the application of the active ingredient. Thus, the insulating layer has no active role in the release and diffusion of the active ingredient, and no specific protection of the active ingredient is provided. WO2011/133765 discloses a pH-sensitive encapsulation method capable of releasing an active ingredient when the seed is exposed to a pH change. The active ingredient may be a phytosanitary active ingredient, an attractant or a repellent. However, this method has the disadvantage of being pH-dependent and using a polymer which generates microparticles that can pollute the soil when degraded in it. WO2014/062660 discloses a method of coating seeds using a first polymer to encapsulate the active ingredient by forming a rigid shell around it and a second polymer to adhere the encapsulated active ingredient particles to the seed and allow controlled release of the active ingredient. The encapsulating polymers used are SMA (“styrene maleic anhydride”) or SMI (“styrene maleimide”) polymers, modified or unmodified proteins, or starches. The coating is described as biodegradable. However, due to the use of thermoplastic polymer, microplastics will be generated in the soil, which is an obstacle to the development of this technology. Thus, the coating agents are in most cases of various types of polymers, which can generate soil pollution via the formation of microplastics in particular. In addition, the very use of insecticides in coatings poses environmental problems due to the persistence of the insecticide in the soil and its migration to surface water and groundwater. Indeed, the insecticide does not degrade by itself, hence it accumulates over time, in the soil and in water. Repellent agents can be used in place of agrochemical active ingredients such as insecticides. However, said repellent agent must be present at least during seed germination and plant emergence. But in most cases, repellent agents are volatile, even very volatile, making their effectiveness rather short-lived. Thus, a crucial problem arises regarding the rapid loss of active ingredient that renders a coating containing a repellent agent ineffective in protecting the seed against soil-borne pests. There is therefore a need to develop new treatments, such as coatings for seeds allowing an effective treatment of seeds against pests over time, without generating phytotoxicity problems or soil and groundwater pollution. SUMMARY OF THE INVENTION The composition and kit according to the invention intended for coating seeds allows solving the above-mentioned problems. In particular, it allows to overcome the problem of direct phytotoxicity of the active ingredient (i.e., the semiochemical compound in the sense of the invention) on the seeds, in particular during the seed germination and plant emergence phase; the problem of soil pollution by plastic polymers or by insecticides; and the problem of too rapid disappearance of the active ingredient due to its volatility or its leaching by water. In addition, the dif