Pest control composition

Abstract

The pest control composition contains a plurality of composite particles, each of the composite particles contains a polyolefin core, and the polyolefin of the polyolefin core has 50% by weight or more of monomer structural units derived from olefin monomers based on the total weight of the polyolefin. Each of the composite particles also contains a plurality of monomer structural units derived from vinyl monomers polymerized on the polyolefin core, and the vinyl monomers include one or more (meth)acrylic monomers. The composition also contains Bacillus thuringiensis and water.

Description

Technical Field

[0001] The present disclosure generally relates to pest control compositions, and more specifically to pest control compositions containing composite particles.

Background Art

[0002] Pest control agents are used to control pests such as insects. The effectiveness of pest control agents can be affected by many factors. In the industry, continuous emphasis has been placed on the development of new and improved pest control compositions.

Summary of the Invention

[0003] According to a first feature of the present disclosure, a pest control composition includes a plurality of composite particles, each of the composite particles includes a polyolefin core, and the polyolefin of the polyolefin core has 50% by weight or more of monomer structural units derived from olefin monomers based on the total weight of the polyolefin. Each of the composite particles also includes a plurality of monomer structural units derived from vinyl monomers polymerized on the polyolefin core, and the vinyl monomers include one or more (meth)acrylic monomers. The composition also includes Bacillus thuringiensis and water. According to a second feature of the present disclosure, the composite particles are 0.1% by weight to 15.0% by weight of the composition based on the total weight of the combination of the composite particles, Bacillus thuringiensis, and water. According to a third feature of the present disclosure, the polyolefin core of the composite particles includes an ethylene / octene copolymer. According to a fourth feature of the present disclosure, water is 20.00% by weight to 99.89% by weight of the composition based on the total weight of the combination of the composite particles, the pest control agent, and water. According to a fifth feature of the present disclosure, the weight ratio of the polyolefin core to the monomer structural units derived from vinyl monomers in the composite particles is 90:10 to 60:40. According to a sixth feature, the weight ratio of the polyolefin core to the monomer structural units derived from vinyl monomers in the composite particles is 80:20. According to a seventh feature, the polyolefin core is crosslinked.

Modes for Carrying Out the Invention

[0004] Unless otherwise indicated, all ranges include their endpoints. Subscript values in polymer formulas refer to the molar average value of the specified component in the polymer.

[0005] Test methods refer to the latest test method at the priority date of this document, unless the date is indicated by a two-digit number with a hyphen in the test method number. References to test methods include both a reference to the test society and the test method number. Test method organizations are referenced by one of the following abbreviations. That is, ASTM refers to ASTM International (formerly, American Society for Testing and Materials), EN refers to European Norm, DIN refers to Deutsches Institut fur Normung, and ISO refers to International Organization for Standards.

[0006] As used herein, "weight %" or "weight percent" or "percent by weight" of a component is based on the total weight of the composition or article in which the component is included, unless otherwise indicated. As used herein, all percentages are by weight, unless otherwise specified.

[0007] This specification discloses a pest control composition. Each embodiment of the present disclosure provides a pest control composition comprising a plurality of composite particles, Bacillus thuringiensis, and water.

[0008] The pest control composition disclosed herein can be applied to a plant (e.g., the plant surface) to control pests. Advantageously, the pest control composition disclosed herein can provide an improved (i.e., higher) residual protein concentration of Bacillus thuringiensis after exposure to rain compared to other formulations. The improved residual protein concentration indicates that the pest control composition disclosed herein can result in improved pest control compared to other formulations.

[0009] Furthermore, the pest control composition disclosed herein can provide a retention rate (%) of Bacillus thuringiensis activity exceeding 80% after exposure to rain. Providing a retention rate (%) of Bacillus thuringiensis activity exceeding 80% can indicate a desirable degree of rain resistance.

[0010] The pest control composition disclosed herein comprises a plurality of composite particles. Embodiments of the present disclosure define that each of the composite particles comprises a polyolefin core and a plurality of monomer structural units derived from vinyl monomers polymerized on the polyolefin core. The term "shell" can be used herein to generally describe the polymerization of a plurality of monomer structural units derived from vinyl monomers onto the polyolefin core, but the term "shell" does not limit in any way the distribution, orientation, spacing, or continuity of the monomer structural units derived from vinyl monomers throughout the core.

[0011] As described above, the composite particles include a polyolefin core (e.g., a core polymer). As used herein, "polymer" has two or more identical or different monomer structural units derived from a number of monomers (e.g., homopolymer, copolymer, terpolymer, etc.). When used herein with respect to a polymer, "monomer structural unit" refers to a portion of the polymer structure resulting from the reaction of one or more monomers that form the polymer. With respect to monomer structural units, "different" means that the monomer polymer structural units differ from each other by at least one atom or are isomerically different. As used herein, "polyolefin" refers to a polymer having at least 50% by weight of monomer structural units derived from olefins based on the total weight of the polymer. "Olefin" refers to a compound that is a hydrocarbon having one or more carbon-carbon double bonds and no aromatic ring, e.g., a monomer. As used herein, "a" refers to one or more, unless otherwise specified. The polyolefin core may be crosslinked.

[0012] The core polymer includes a polyolefin. Embodiments of the present disclosure provide that the core polymer may include a hydrocarbon polyolefin and / or a non-hydrocarbon polyolefin. For example, a polyolefin containing only monomer structural units derived from hydrocarbon monomers is considered a hydrocarbon polyolefin even if a small number of hetero groups are attached to the polyolefin as fragments from an initiator and / or a chain transfer agent. In a hydrocarbon polyolefin, the molar ratio of heteroatoms to the polymerization units of all monomers is 0.001:1 or less. A polyolefin that is not a hydrocarbon polyolefin is considered a non-hydrocarbon polyolefin (e.g., a polyolefin containing one or more hetero groups). As used herein, atoms other than carbon and hydrogen are considered "hetero" atoms. A chemical group having one or more heteroatoms is considered a "hetero" group.

[0013] Examples of hydrocarbon polyolefins include, but are not limited to, hydrocarbon polyolefins having monomer structural units derived from ethylene and one or more α-olefins. Examples of α-olefins include propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-hexene, 1-octene, 1-decene, 1-dodecene, and combinations thereof. Further examples of hydrocarbon polyolefins include polymers of one or more dienes with ethylene, one or more α-olefins, or combinations thereof. Examples of dienes include butadiene, dicyclopentadiene, 1,5-hexadiene, ethylidene norbornene, and vinyl norbornene.

[0014] Hydrocarbon polyolefins can be prepared using known apparatus, reaction components, and reaction conditions. Hydrocarbon polyolefins are commercially available. Examples of suitable commercially available hydrocarbon polyolefins include, but are not limited to, those sold under the trade names VERSIFY™, NORDEL™, or ENGAGE™ by The Dow Chemical Company, and those sold under the trade names VISTAMAXX™, VISTALON™, or EXACT™ by ExxonMobil Chemical Company.

[0015] As described above, the core polymer may include a non-hydrocarbon polyolefin. The non-hydrocarbon polyolefin can contain hetero groups. Examples of hetero groups include, but are not limited to, carboxyl groups, ester groups, anhydride groups, alkoxysilane groups, and combinations thereof. The hetero groups may be bonded to the comonomer prior to polymerization or added to the non-hydrocarbon polyolefin by grafting after polymerization. In one or more embodiments of the present disclosure, maleic anhydride grafted onto a hydrocarbon polyolefin can be used. Unsaturated compounds containing heteroatoms can be grafted onto hydrocarbon polyolefins by any effective method, such as by a free radical method, in the presence of, for example, a free radical initiator or in the presence of ionizing radiation. Examples of non-hydrocarbon polyolefins are copolymers of one or more α-olefins and one or more monomers such as vinyl acetate, ethyl acrylate, vinyl alcohol, vinyl chloride, and (meth)acrylic monomers.

[0016] Non-hydrocarbon polyolefins can be prepared using known equipment, reaction components, and reaction conditions. Non-hydrocarbon polyolefins are commercially available. Examples of suitable commercially available non-hydrocarbon polyolefins include, but are not limited to, those with the trade names AMPLIFY™, PARALOID™, or RETAIN™ available from The Dow Chemical Company, those with the trade name FUSABOND™ available from E.I. DuPont de Nemours, those with the trade name POLYBOND™ available from Chemtura Corporation, and those with the trade name LICOCENE™ available from Clariant International Ltd.

[0017] The polyolefin can contain a crosslinking agent. For example, the crosslinking agent can be used to crosslink the polyolefin of the polyolefin core. The crosslinking agent can include a monomer crosslinking agent, a polymer crosslinking agent, or a combination thereof. Examples of the crosslinking agent include, but are not limited to, triallyl isocyanurate, 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane, triallyl cyanurate, triallyl trimellitate, tri(methylallyl) isocyanurate, tris(diallylamine)-s-triazine, triallyl phosphite, N,N-diallyl acrylamide, N,N,N’,N’,N’’,N’’-hexaallyl phosphoramide, N,N,N’,N’-tetraallyl terephthalamide, N,N,N’,N’-tetraallylinalonamide, trivinyl isocyanurate, methyl-2,4,6-trivinyltrisiloxane, N,N’-m-phenylene bismaleimide, diallyl phthalate, tri(5-norbornenyl-2-methylene) cyanurate, and combinations thereof. The monomer crosslinking agent can have two or more carbon-carbon double bonds, or three or more carbon-carbon double bonds. Examples of the polymer crosslinking agent include, but are not limited to, polyolefins having carbon-carbon double bonds. The polymer crosslinking agent can be a homopolymer, copolymer, or a combination thereof containing monomer structural units derived from one or more dienes.

[0018] The polyolefin core can be prepared using known apparatuses, reaction components, and reaction conditions. An example of a suitable method for preparing the polyolefin core is as follows.

[0019] One or more hydrocarbon polyolefins and one or more non-hydrocarbon polyolefins can be supplied from a supply port to an extruder. The hydrocarbon polyolefin and the non-hydrocarbon polyolefin can be added to the extruder separately, added to the extruder as a mixture after being mixed with each other, or compounded with each other by melt mixing before being added to the extruder. When the crosslinking agent is solid at 25°C, it can also be supplied from the supply port together with the hydrocarbon polyolefin and the non-hydrocarbon polyolefin. When the crosslinking agent is liquid at 25°C, it can be injected into the melt zone of the extruder via a pump. The hydrocarbon polyolefin, the non-hydrocarbon polyolefin, and the crosslinking agent are mixed with each other in a molten state in the extruder, and then can be emulsified in the extruder by adding water and a surfactant via a pump. Water can be added to achieve a desired solid content. For example, the emulsion can have a water content of 60% to 90% by weight based on the total weight of the emulsion. Such an emulsion can have a solid content of 5% to 50% by weight based on the total weight of the emulsion. The surfactant can be 0.5% to 10% by weight of the emulsion based on the total weight of the emulsion. As used herein, the terms "emulsion" and "dispersion" are used interchangeably. Examples of commercially available surfactants include, among others, those available under the trade name EMPICOL™.

[0020] The surfactant is, for example, an anionic surfactant containing a hydrocarbon group having 8 or more carbon atoms and an anionic group. The hydrocarbon group may be linear, branched, aromatic, or a combination thereof. The anionic group is a chemical group that is negatively charged in water at pH 7. Examples of the anionic group include, but are not limited to, phosphate group, phosphonate group, carboxylate group, sulfate group, and sulfonate group. The anionic surfactant can contain a (CH 2 CH 2 O) n group (wherein n is from 1 to 20). (CH 2 CH 2 O) nThe base may be bonded to, for example, a sulfate group.

[0021] One method of making such an emulsion is described in US Patent Application Publication No. 2016 / 0177077. Then, additional water can be added to the extruder to make the dispersion exiting the extruder have a solids content of less than 70% by weight based on the total weight of the dispersion. One or more embodiments provide for first emulsifying the polyolefin as described above and then adding a crosslinking agent to the emulsion, preferably when the emulsion is maintained at a temperature higher than the melting point of one or more of the polyolefins.

[0022] After a dispersion prepared from a hydrocarbon polyolefin, a non-hydrocarbon, and a crosslinking agent is formed, an initiator such as a peroxide initiator can be added to the dispersion. The peroxide initiator has the structure R 1 -O-O-R 2 (wherein R 1 and R 2 are each independently H or an organic group). R 1 and R 2 can each independently be H or an alkyl group, for example, an alkyl group having 2 to 12 carbon atoms independently. Examples of peroxide initiators include, but are not limited to, hydrogen peroxide, alkyl hydroperoxides, t-butyl hydroperoxide, and combinations thereof. The peroxide initiator can be used at a concentration of 0.02% to 2% by weight based on the total weight of the solids of the emulsion. Examples of other suitable initiators include thermal initiators and photoinitiators.

[0023] When combining an initiator with a dispersion, a reducing agent may be used to form, for example, a redox initiator together with a peroxide initiator. Examples of reducing agents include, but are not limited to, ascorbic acid, isoascorbic acid, sodium formaldehyde sulfoxylate, tetramethylethylenediamine, sodium metabisulfite, and combinations thereof. The molar ratio of peroxide to reducing agent can be 0.7:1 or more, 0.8:1 or more, or 0.9:1 or more, and the molar ratio of peroxide to reducing agent can be 1.3:1 or less, 1.2:1 or less, or 1.1:1 or less. An oxidation / reduction catalyst may be used for the oxidation / reduction reaction of the peroxide initiator and the reducing agent. Examples of oxidation / reduction catalysts include, but are not limited to, salts of iron(II), and FeSO 4 can be used. The oxidation / reduction catalyst can be used at a concentration of 1 part per million (ppm) to 50 ppm based on the total weight of the solids of the emulsion.

[0024] The polyolefin core can contain 50 wt% to 95 wt% hydrocarbon polyolefin based on the total weight of the polyolefin core (e.g., based on the total weight of hydrocarbon polyolefin, non-hydrocarbon polyolefin, and crosslinking agent such that the total weight of hydrocarbon polyolefin, non-hydrocarbon polyolefin, and crosslinking agent totals 100 wt%). All individual values and subranges from 50 wt% to 95 wt% are included. For example, the polyolefin core can contain hydrocarbon polyolefin from a lower limit of 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, or 75 wt% to an upper limit of 95 wt%, 92 wt%, 90 wt%, 85 wt%, 83 wt%, or 80 wt% based on the total weight of the polyolefin core.

[0025] The polyolefin core can contain 2 wt% to 50 wt% of a non-hydrocarbon polyolefin, based on the total weight of the polyolefin core (e.g., based on the total weight of the hydrocarbon polyolefin, non-hydrocarbon polyolefin, and crosslinking agent such that the total weight of the hydrocarbon polyolefin, non-hydrocarbon polyolefin, and crosslinking agent totals 100 wt%). All individual values and subranges from 2 wt% to 50 wt% are included. For example, the polyolefin core can contain from 2 wt%, 3 wt%, 5 wt%, 7.5 wt%, 10 wt%, or 12 wt% as a lower limit to 50 wt%, 45 wt%, 40 wt%, 35 wt%, 30 wt%, or 20 wt% as an upper limit of non-hydrocarbon polyolefin, based on the total weight of the polyolefin core.

[0026] The polyolefin core can contain 0.5 wt% to 20 wt% of a crosslinking agent, based on the total weight of the polyolefin core (e.g., based on the total weight of the hydrocarbon polyolefin, non-hydrocarbon polyolefin, and crosslinking agent such that the total weight of the hydrocarbon polyolefin, non-hydrocarbon polyolefin, and crosslinking agent totals 100 wt%). All individual values and subranges from 0.5 wt% to 20 wt% are included. For example, the polyolefin core can have from 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, or 3.0 wt% as a lower limit to 20 wt%, 18 wt%, 15 wt%, 12 wt%, or 10 wt% as an upper limit of crosslinking agent, based on the total weight of the polyolefin core.

[0027] As described above, the composite particles include a polyolefin core and a shell containing monomer structural units derived from vinyl monomers. The composite particles can be prepared, for example, by emulsion polymerization to form the shell using one or more vinyl monomers in the presence of polyolefin core particles.

[0028] For example, one or more vinyl monomers can be combined with water and a surfactant to form an emulsion of droplets in an aqueous medium containing the vinyl monomer (e.g., a (meth)acrylic monomer). Next, a dispersion of polyolefin core particles (e.g., those discussed above), an emulsion of vinyl monomer droplets, and a water-soluble initiator can be formed. By subjecting this mixture to known emulsion polymerization conditions, the initiator can generate radicals and a shell (e.g., a polymer) containing monomer structural units derived from the vinyl monomer.

[0029] Examples of vinyl monomers include (meth)acrylic monomers, vinyl aromatic monomers, and combinations thereof. Examples of (meth)acrylic monomers include, but are not limited to, (meth)acrylic acid, its unsubstituted alkyl esters, its substituted alkyl esters, and combinations thereof. Examples of unsubstituted alkyl esters of acrylic acid include, but are not limited to, those having an alkyl group with 2 to 18 carbon atoms. Examples of unsubstituted alkyl esters of methacrylic acid include, but are not limited to, those having an alkyl group with 1 to 4 carbon atoms. One or more embodiments define that the vinyl monomer is methyl methacrylate, butyl acrylate, or a combination thereof.

[0030] Embodiments of the present disclosure define that the weight ratio of the polyolefin core particles to the plurality of monomer structural units derived from the vinyl monomer in the composite particles is from 90:10 to 60:40. All individual values and subranges from 90:10 to 60:40 are included. For example, the weight ratio of the polyolefin core particles to the plurality of monomer structural units derived from the vinyl monomer in the composite particles may be 90:10, 85:15, 80:20, 75:25, 70:30, 65:35, or 60:40.

[0031] Following the emulsion polymerization process and / or dilution used to form the composite particles, the composite particles can be dispersed in an aqueous medium. Different amounts of water can be used for different applications. For example, the dispersion containing the composite particles can have a solids content of 15% to 85% by weight based on the total weight of the dispersion (e.g., the total weight of the solid component and the liquid component). All individual values and sub-ranges from 15% to 85% by weight are included. For example, the dispersion containing the composite particles can have a solids content ranging from a lower limit of 15%, 20%, 25%, 30%, 35%, or 40% by weight to an upper limit of 85%, 80%, 75%, 70%, 65%, or 60% by weight based on the total weight of the dispersion.

[0032] The composite particles can have a volume average particle size of 100 nanometers (nm) to 2000 nm. All individual values and sub-ranges from 100 to 2000 nm are included. For example, the composite particles can have a volume average particle size ranging from a lower limit of 100 nm, 150 nm, 200 nm, or 250 nm to an upper limit of 2000 nm, 1000 nm, 750 nm, or 500 nm. The particle size analysis is performed using a Beckman Coulter LS 13320 laser light scattering particle size analyzer (Beckman Coulter Inc., Fullerton, California).

[0033] The pest control composition disclosed herein contains a plurality of composite particles, and the composite particles include a polyolefin core and a shell containing monomer structural units derived from the vinyl monomers discussed herein. The composite particles can be used in the pest control composition as a component of the dispersion. The composite particles can be used in the pest control composition as a powder. For example, the dispersion containing the composite particles can be dried to obtain a powder containing the composite particles. Suitable methods for removing water (i.e., drying) from the dispersion containing the composite particles include, for example, spray drying and coagulation.

[0034] The pest control composition disclosed herein contains Bacillus thuringiensis. As defined herein, "Bacillus thuringiensis" is a spore and / or crystallized protein of the Bacillus thuringiensis species, and includes all subspecies of Bacillus thuringiensis that exhibit insecticidal properties. Examples of such subspecies include kurstaki, israelensis, and aizawa. Bacillus thuringiensis can be added to the insecticidal formulation either as part of a solid or liquid formulation. The presence and subspecies of Bacillus thuringiensis are determined by random amplified polymorphic DNA analysis. A commercially available liquid formulation of Bacillus thuringiensis is the THURICIDE™ insecticide marketed by CERTIS USA (Columbia, Maryland). Bacillus thuringiensis can produce insecticidal crystal proteins (such as Cry proteins and Cyt proteins) by sporulation. By becoming more active after exposure to light, it can provide desirably improved pest control properties. A higher residual protein concentration (such as residual Cry protein concentration and / or Cyt protein concentration) after exposure to rainfall can provide desirably improved pest control properties.

[0035] The pest control composition disclosed herein can contain water. Different amounts of water can be used for different applications.

[0036] One or more embodiments of the present disclosure provide that the pest control composition disclosed herein can contain additives. Examples of additives include, among others, viscosity modifiers, pH adjusters, herbicides, fungicides, and combinations thereof. Different amounts of additives can be used for various applications.

[0037] As described above, the pest control composition disclosed in this specification contains composite particles. The composite particles can be 0.1% to 15.0% by weight of the pest control composition based on the total weight of the combination of the composite particles, Bacillus thuringiensis, and water. For example, the composite particles can be 0.1% by weight or more, or 0.5% by weight or more, or 1.0% by weight or more, or 1.5% by weight or more, or 2.0% by weight or more, or 2.5% by weight or more, or 3.0% by weight or more, or 3.5% by weight or more, or 4.0% by weight or more, or 4.5% by weight or more, or 5.0% by weight or more, or 5.5% by weight or more, or 6.0% by weight or more, or 6.5% by weight or more, or 7.0% by weight or more, or 7.5% by weight or more, or 8.0% by weight or more, or 8.5% by weight or more, or 9.0% by weight or more, or 9.5% by weight or more, or 10.0% by weight or more, or 10.5% by weight or more, or 11.0% by weight or more, or 11.5% by weight or more, or 12.0% by weight or more, or 12.5% by weight or more, or 13.0% by weight or more, or 13.5% by weight or more, or 14.0% by weight or more, or 14.5% by weight or more, and at the same time 15.0% by weight or less, or 14.5% by weight or less, or 14.0% by weight or less, or 13.5% by weight or less, or 13.0% by weight or less, or 12.5% by weight or less, or 12.0% by weight or less, or 11.5% by weight or less, or 11.0% by weight or less, or 10.5% by weight or less, or 10.0% by weight or less, or 9.5% by weight or less, or 9.0% by weight or less, or 8.5% by weight or less, or 8.0% by weight or less, or 7.5% by weight or less, or 7.0% by weight or less, or 6.5% by weight or less, or 6.0% by weight or less, or 5.5% by weight or less, or 5.0% by weight or less, or 4.5% by weight or less, or 4.0% by weight or less, or 3.5% by weight or less, or 3.0% by weight or less, or 2.5% by weight or less, or It can be a combination of composite particles, Bacillus thuringiensis, and water that is 2.0% by weight or less, or 1.5% by weight or less, or 1.0% by weight or less, or 0.5% by weight or less.

[0038] The pest control composition disclosed in this specification contains Bacillus thuringiensis. Bacillus thuringiensis can be 0.01% to 25.00% by weight of the pest control composition based on the total weight of the combination of composite particles, Bacillus thuringiensis, and water. All individual values and sub-ranges from 0.01% to 25.00% by weight are included. For example, the pest control composition can contain Bacillus thuringiensis from a lower limit of 0.01%, 0.05%, or 1.0% by weight to an upper limit of 25.00%, 15.00%, or 10.00% by weight based on the total weight of the combination of composite particles, Bacillus thuringiensis, and water.

[0039] The pest control composition disclosed in this specification contains water. Water can be 60.00% to 99.89% by weight of the pest control composition based on the total weight of the combination of composite particles, Bacillus thuringiensis, and water. All individual values and sub-ranges from 20.00% to 99.89% by weight are included. For example, the pest control composition can contain water from a lower limit of 20.00%, 30.00%, or 40.00% by weight to an upper limit of 99.89%, 98.00%, or 95.00% by weight based on the total weight of the combination of composite particles, Bacillus thuringiensis, and water. Water can be incorporated into the pest control composition by a dispersion containing composite particles, and / or water can be added to the pest control composition by addition regardless of the dispersion.

[0040] The pest control composition disclosed in this specification can be formed using known devices and processes. Each component of the pest control composition can be combined (e.g., mixed) to form the pest control composition. For example, each component of the pest control composition can be added to a container and stirred in the container. Each component of the pest control composition can be added in any order.

[0041] The pest control composition disclosed in this specification can be applied to plants (e.g., the plant surface) to control pests. The pest control composition can be applied to plants using known devices and methods. For example, the pest control composition can be sprayed, scattered, and / or poured onto plants, among other application methods. Different amounts of the pest control composition can be applied to plants for various uses.

Examples

[0042] In the examples, various terms and names related to materials are used, including, for example, the following.

[0043] ENGAGE™ 8137 (hydrocarbon polyolefin, an ethylene-octene copolymer obtained from The Dow Chemical Company); LICOCENE™ PR MA 4351 (non-hydrocarbon polyolefin, a maleated polyethylene wax obtained from Clariant, 5 wt% maleic anhydride); RETAIN™ 3000 (non-hydrocarbon polyolefin, an ethylene / octene copolymer grafted with maleic anhydride groups obtained from The Dow Chemical Company); EMPICOL™ ESB70 (surfactant, sodium lauryl ether sulfate obtained from Huntsman); triallyl isocyanurate (crosslinking agent, obtained from Nippon Kayaku Co., Ltd.); methyl methacrylate (vinyl monomer); butyl acrylate (vinyl monomer); a copolymer of polyethylene-polyvinyl acetate (20 wt% polyethylene, 80 wt% vinyl acetate, CAS number: 24937-78-8, obtained from Polysciences Inc.).

[0044] Composite particles were formed as follows. An aqueous polyolefin dispersion (referred to as the first dispersion) containing polyolefin core particles was prepared using a twin-screw extruder (screw diameter 25 mm, 48 L / D rotating at 450 rpm). ENGAGE (trademark) 8137, LICOCENE (trademark) PE MA 4351, and RETAIN (trademark) 3000 were each fed into the feed port of the extruder via a Schenck Mechatron loss-in-weight feeder and a Schenck volumetric feeder. Triallyl isocyanurate was injected into the polymer melt zone using an Isco dual syringe pump (obtained from Teledyne Isco, Inc.). The polymers were then melt blended and emulsified in the presence of a first water stream and EMPICOL (trademark) ESB 40. The emulsion phase was then transported to the dilution and cooling zone of the extruder where additional dilution water was added to form an aqueous dispersion (i.e., the first dispersion) having a solids content of less than 70 wt%. The first water stream and the dilution water were supplied by an Isco dual syringe pump. The barrel temperature of the extruder was set at 140 - 150 °C. After the dispersion exited the extruder, it was further cooled and filtered through a bag filter with a mesh size of 200 μm. The aqueous polyolefin dispersion had a solids content in water of 50 wt% and contained polyolefin core particles. The aqueous polyolefin dispersion contained ENGAGE (trademark) 8137 (79 wt%), LICOCENE (trademark) 4351 (5 wt%), RETAIN (trademark) 3000 (10 wt%), EMPICOL (trademark) ESB (4 wt%), and triallyl isocyanurate (2 wt%).

[0045] The first dispersion (i.e., a polyolefin dispersion containing polyolefin core particles) was diluted with water in a 1 L three-necked flask equipped with a condenser and a mechanical stirrer to a solid content of about 40 wt% at pH 4 - 5. A stir bar was inserted through a Teflon (registered trademark) adapter and a glass sleeve and connected to the central neck of the flask. The stirring speed was set at 200 rpm, and nitrogen was slowly purged through the reactor. Cooling water was passed through the condenser. Next, 5 ppm of iron(II) sulfate heptahydrate and 25 ppm of ethylenediaminetetraacetic acid (EDTA) were added based on the total weight of the diluted dispersion, and the mixture was heated to 65 °C using a heating mantle. Solutions of tert-butyl hydroperoxide (t-BHP, 0.3 wt% based on the total weight of the diluted dispersion) and sodium formaldehyde sulfoxylate (SFS, 0.3 wt% based on the total weight of the diluted dispersion) in deionized water were each supplied to the reactor over 60 minutes using a syringe pump. The reactor was then held at 65 °C for 30 minutes. Separately, a monomer emulsion containing methyl methacrylate (98 wt%) and butyl acrylate (2 wt%) in deionized water was prepared in the presence of sodium dodecylbenzenesulfonate (DS-4, 0.04 wt% based on the total weight of methyl methacrylate and butyl acrylate). Solutions of t-BHP (0.2 wt% based on the total weight of methyl methacrylate and butyl acrylate) and SFS (0.17 wt% based on the total weight of methyl methacrylate and butyl acrylate) in deionized water were prepared and loaded into a syringe pump for delivery. The monomer emulsion and the t-BHP / SFS solution were co-fed simultaneously to the reactor at 65 °C. The monomer emulsion was fed over 60 minutes, and the t-BHP / SFS solution was fed over a total of 90 minutes. After the reactor was held at 65 °C for 30 minutes, the contents of the reactor (i.e., the dispersion containing the composite particles considered herein (referred to as the second dispersion)) were cooled to about 25 °C and filtered through a 150 μm mesh filter. In the composite particles, the weight ratio of the polyolefin core particles to the plurality of monomer structural units derived from the vinyl monomer was 80:20. The dispersion had a solid content of 42.0 wt%, and the composite particles had a volume-average particle diameter of 350 nanometers.Particle size analysis was performed using a Beckman Coulter LS13320 laser light scattering particle size analyzer (Beckman Coulter Inc., Fullerton, California).

[0046] The pest control composition of Example 1 was formed as follows. A part of the second dispersion (THURICIDE (trademark)) and water were added together to obtain Example 1. Example 1 contained 2.5% by weight of composite particles, and the resulting formulation was further diluted to 2.5 grams / liter.

[0047] Comparative Example A was formed in the same manner as Example 1, except that the first dispersion was used instead of the second dispersion. When forming Comparative Example A, the polyolefin dispersion had a solids content of 52.5% by weight and a volume average particle size of 337 nanometers.

[0048] In Comparative Example B, a copolymer of polyethylene-polyvinyl acetate was used. The polyethylene-polyvinyl acetate copolymer (THURICIDE (trademark)) and water were added together to contain 2.5% by weight of the copolymer, and the resulting formulation was further diluted to 2.5 grams / liter.

[0049] In Comparative Example C, neither the first dispersion nor the second dispersion was used, and THURICIDE (trademark) was diluted to 2.5 grams / liter.

[0050] The residual protein concentration and Bacillus thuringiensis activity for Example 1 and Comparative Examples A - C were determined as follows.

[0051] Parafilm pieces (2 inches × 4 inches) were each placed on a black Leneta card, gently rubbed over the entire Parafilm with a Kimwipe, and then the Parafilm paper was peeled off. Using an automatic pipettor, 15 drops (15 - 30 μL) of Example 1 and Comparative Examples A - C were randomly arrayed on each Parafilm. For each example / comparative example, one Parafilm was used. The samples were vortex - mixed between each set of 5 drops to maintain the consistency of the composition. Then, each Parafilm was dried in an incubator at approximately 28 °C for about 1 hour.

[0052] Next, the dried Parafilms were exposed to simulated rainfall as follows. Each of the dried Parafilms was placed in an EXO TERRA Monsoon RS400 Rainfall System (equipped with 2 Exo Terra standard nozzles without extension). The Parafilm was 13 inches from the spray nozzle. Water was sprayed onto the Parafilm at a flow rate of 1.5 liters / hour for 5 minutes as measured at the substrate interface. Then, the Parafilm was dried.

[0053] After exposure to simulated rainfall, the samples were extracted. For extraction, each of the Parafilms was cut such that the center of each dot obtained from the droplet was approximately 0.25 - inch square. For each Parafilm, all of the cut squares with dots were placed in a glass vial, and sodium dodecyl sulfate solution (1 milliliter, 2 wt% aqueous sodium dodecyl sulfate solution) was added thereto. Then, each glass vial was sonicated and immersed for about 8 hours. Sonication was repeated 3 times for extraction.

[0054] The residual protein concentration was determined by the bicinchoninic acid assay (BCA) as follows. PIERCE™ BCA Protein Assay Reagent A and PIERCE™ BCA Protein Assay Reagent B (both manufactured by Thermo Scientific™) were combined with reagent A (2 milliliters) and reagent B (40 microliters) to form a reagent mixture.

[0055] 100 microliters of each extraction sample (extracted Example 1 and Comparative Examples A - C) were placed in separate cuvettes. Then, the reagent mixture (2 milliliters) was added to each cuvette, and the cuvettes were incubated at 30 °C for about 2 hours. The residual protein concentration was measured using the absorbance value at 562 nm determined by a Cary100 UV - visible spectrophotometer. The results are shown in Table 1.

Table 1

[0056] The data in Table 1 show that Example 1 has an improved (i.e., higher) residual protein concentration compared to each of Comparative Examples A - C.

[0057] Each solution extracted above for Example 1 and Comparative Examples A - C was diluted to the desired starting concentration using a 0.1 wt% solution of TWEEN® 20 and then serially diluted to appropriate concentrations for plating. The resulting Bacillus thuringiensis activity is shown in Table 2.

Table 2

[0058] The data in Table 2 show that each of Example 1 and Comparative Examples A - B had a retention rate (%) of Bacillus thuringiensis activity exceeding 80%.

Claims

1. A plurality of composite particles, each of the composite particles comprising: a polyolefin core, wherein the polyolefin of the polyolefin core has, based on the total weight of the polyolefin, 50% by weight or more of monomer structural units derived from olefin monomers; a polyolefin core; a plurality of monomer structural units derived from vinyl monomers polymerized on the polyolefin core, the vinyl monomers including one or more (meth)acrylic monomers; and a plurality of composite particles; Bacillus thuringiensis; water; and a pest control composition.

2. The pest control composition according to claim 1, wherein the composite particles are 0.1% by weight to 15.0% by weight of the composition based on the total weight of the combination of the composite particles, Bacillus thuringiensis, and the water.

3. The pest control composition according to any one of claims 1 to 2, wherein the polyolefin core of the composite particles comprises an ethylene / octene copolymer.

4. The pest control composition according to any one of claims 1 to 3, wherein the water is 20.00% by weight to 99.89% by weight of the composition based on the total weight of the combination of the composite particles, Bacillus thuringiensis, and the water.

5. The pest control composition according to any one of claims 1 to 4, wherein the weight ratio of the polyolefin core to the monomer structural units derived from vinyl monomers in the composite particles is 90:10 to 60:

40.

6. The pest control composition according to claim 5, wherein the weight ratio of the polyolefin core to the monomer structural units derived from vinyl monomers in the composite particles is 80:

20.

7. The pest control composition according to any one of claims 1 to 6, wherein the polyolefin core is crosslinked.

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