Seed coating composition

Abstract

The seed coating composition includes a silane-functionalized polymer. The silane-functionalized polymer is acrylate-based. The seed coating composition also includes a polydimethylsiloxane having a weight average molecular weight of 500,000 g / mol or more, as measured by gel permeation chromatography.

Description

Technical Field

[0001] The present disclosure relates to a composition, and more specifically, to a seed coating composition.

Background Art

[0002] Introduction Seeds used for cultivating crops often include one or more coatings disposed on the outer surface of the seeds. The coating can attach agricultural active ingredients (e.g., fertilizers, pesticides, antibacterial agents, plant growth regulators) to the surface of the seeds and / or impart various beneficial properties (e.g., protection of seeds from bacteria / insects / damage, promotion of plant growth, gas or water permeability, etc.). During the production, transportation, and planting of seeds, the coating is exposed to various conditions such as mechanical forces and moisture that can adversely affect the integrity of the coating and / or the attachment of the coating to the seeds. The resistance of the coating to flaking and chipping due to mechanical forces is quantified as its "attrition rate", with a lower value indicating less loss of the coating. Generally, an attrition rate exceeding 8% is considered unacceptable. The coating must also be resistant to dissolution when exposed to water, and the coefficient of friction of the surface must be low so that the coated seeds do not aggregate and bond to each other during handling.

[0003] Various attempts have been made to improve the properties of the coating. For example, U.S. Patent No. 5,106,649 ("the '649 patent") discloses the use of a polydimethylsiloxane ("PDMS") lubricant in combination with a polyethylene glycol, alkyd resin, or polyacrylate-based coating to improve the bulk flow properties of pesticide-treated seeds. Specifically, the '649 patent utilizes PDMS having a molecular weight of 10,000 grams per mole ("g / mol") to 400,000 g / mol, more preferably 50,000 g / mol to 200,000 g / mol.

[0004] Improving the adhesion between a seed coating and a seed has mainly been attempted through coating functionalization using monomers such as maleic anhydride. The use of silane functionalization to increase the adhesion between a polymer and an inorganic surface is known, and the same applies to the silane functionalization of acrylate polymers. For example, U.S. Patent Publication No. 2004 / 0259991 (A1) discloses a self-stabilizing silane-modified (meth)acrylic latex interpolymer composition. However, due to regulations implemented by the U.S. Environmental Protection Agency (EPA) and adopted in other jurisdictions, silane-functionalized polymers have not been used in relation to agricultural seeds. Therefore, the effectiveness of silane functionalization for seed coatings is not known.

[0005] Competing with the coating properties listed above is the requirement that the coating does not inhibit seed germination. For example, the coating must be permeable to moisture and gas in order for the seed to initiate germination. Furthermore, the adhesion of the coating to the seed and / or the rigidity of the coating must not prevent the opening of the seed and the emergence of the new plant. Generally, a seed coating that results in less than 85% seed germination is considered unacceptable.

[0006] Considering the above, it would be surprising to discover a seed coating composition that has a wear rate of less than 8% and meets the requirements for water resistance and fluidity while achieving a germination rate of 85% or more. SUMMARY OF THE INVENTION

[0007] The present invention provides a seed coating composition that achieves a seed germination rate of 85% or more, has a wear rate of less than 8%, and meets the requirements for water resistance and fluidity.

[0008] The present invention results from the discovery that by utilizing a silane-functionalized polymer in combination with a polydimethylsiloxane having a weight average molecular weight of 500,000 g / mol or more, it is possible to form a seed coating composition that can satisfy the above characteristics. Without being bound by theory, it is believed that the silane-functionalization of the polymer can effectively bind to the outer surface of the seed, while the polydimethylsiloxane can reduce the coefficient of friction of the coating. Surprisingly, it has been discovered that despite the increased adhesion provided by the use of the silane-functionalized polymer, the seed coating composition does not overly inhibit germination, and more than 85% of the seeds can germinate. Furthermore, it is surprising that the incorporation of polydimethylsiloxane having a weight average molecular weight of 500,000 g / mol or more does not thicken the coating to the point where germination is reduced to less than 85%.

[0009] The present invention is particularly useful for use in the protection of seeds.

[0010] According to a first aspect of the present disclosure, a seed coating composition comprises a silane-functionalized polymer, wherein the silane-functionalized polymer is acrylate-based, and a polydimethylsiloxane having a weight average molecular weight of 500,000 g / mol or more as measured according to gel permeation chromatography.

[0011] According to a second aspect of the present disclosure, the silane-functionalized polymer comprises units derived from a silane monomer selected from the group consisting of vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, and combinations thereof.

[0012] According to a third aspect of the present disclosure, the silane-functionalized polymer comprises units derived from butyl acrylate, methyl methacrylate, methacrylic acid, and styrene.

[0013] According to a fourth feature of the present disclosure, the polydimethylsiloxane has a weight average molecular weight of 500,000 g / mol to 2,500,000 g / mol as measured according to gel permeation chromatography.

[0014] According to a fifth feature of the present disclosure, the silane-functionalized polymer has a glass transition temperature of 0°C to 40°C as measured according to ASTM D7028.

[0015] According to a sixth feature of the present disclosure, the weight ratio of the silane-functionalized polymer to the polydimethylsiloxane in the seed coating composition is 99:1 to 75:25.

[0016] According to a seventh feature of the present disclosure, the weight ratio of the silane-functionalized polymer to the polydimethylsiloxane in the seed coating composition is 96:4 to 85:15.

[0017] According to an eighth feature of the present disclosure, the seed coating composition further contains water, and the silane-functionalized polymer, the polydimethylsiloxane, and the water form an emulsion.

[0018] According to a ninth feature of the present disclosure, the coated seed includes a seed defining an outer surface, and a seed coating composition in contact with the outer surface of the seed.

[0019] According to a tenth feature of the present disclosure, a method of forming a coated seed includes forming a silane-functionalized polymer that is acrylate-based, combining a polydimethylsiloxane having a weight average molecular weight of 500,000 g / mol or more as measured by gel permeation chromatography with the silane-functionalized polymer to form a seed coating composition, and applying the seed coating composition to the seed to form a coated seed.

BEST MODE FOR CARRYING OUT THE INVENTION

[0020] As used herein, the term "and / or" when used in a listing of two or more items means that any one of the listed items can be used by itself or any combination of two or more of the listed items can be used. For example, if a composition is described as containing component A, B, and / or C, the composition can contain A alone, B alone, C alone, A and B in combination, A and C in combination, B and C in combination, or A, B, and C in combination.

[0021] Unless otherwise indicated, all ranges include their endpoints.

[0022] Test methods refer to the latest test methods at the priority date of this document, unless the test method is indicated by a two-digit number with a hyphen as the test method number and a date. References to test methods include both a reference to the test association and the test method number. Test method organizations are referred to by one of the following abbreviations, where 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.

[0023] As used herein, the term "weight percent" ("wt%") indicates the weight percentage that a component occupies in the total weight of the polymer composition, unless otherwise specified.

[0024] As used herein, "CAS number" is the Chemical Services Registration Number assigned by Chemical Abstracts Service.

[0025] Seed coating composition The present disclosure is directed to a seed coating composition. The seed coating composition includes a silane-functionalized polymer and polydimethylsiloxane. The seed coating composition can exist as an aqueous emulsion or as a coating on a seed. In the aqueous emulsion form of the seed coating composition, the silane-functionalized polymer and polydimethylsiloxane are emulsified in water. As described in more detail below, the aqueous emulsion of the seed coating composition is applied to a seed to form a coated seed. The coated seed exists as a seed with the seed coating composition dried and adhered to the outer surface of the seed.

[0026] Silane-functionalized polymer The seed coating composition includes a silane-functionalized polymer. A "silane-functionalized polymer" is a polymer containing silane. The silane-functionalized polymer is "acrylate-based", which means that the silane-functionalized polymer contains 50 wt% or more, or a majority amount, of polymerization units selected from the group consisting of methyl methacrylate, methacrylate, styrene, butyl methacrylate, acrylic acid, methacrylic acid, methacrylic acid, and 2-ethylhexyl acrylate and trimethylolpropane triacrylate, based on the total weight of the silane-functionalized polymer. As used herein, the term "unit" of a specified monomer refers to the residue of the monomer after polymerization. The silane-functionalized polymer can include a copolymer of silane and monomer, a silane-grafted polymer, and / or a combination thereof. An example of a copolymer of a silane-functionalized polymer is formed from the copolymerization of an acrylate monomer and a silane monomer (such as a vinyl silane monomer), so that the silane monomer is incorporated into the main chain of the polymer. In a grafted example of a silane-functionalized polymer, the silane monomer is grafted onto the main chain of the polymer, so that the monomer or its derivative is pendant away from the main chain.

[0027] "Silane monomer" is a silane-containing monomer that effectively copolymerizes with one of the above-mentioned monomers to form a monomer / silane copolymer or grafts onto the main chain of a polymer formed from the monomer. Representative but non-limiting examples of silane monomers have structure (I),

[0028] [Chemical Formula] wherein R 1 is a hydrogen atom or a methyl group, x is 0 or 1, n is an integer from 1 to 4, or 6, or 8, or 10, or 12, and each R 2 is independently an alkoxy group having 1 to 12 carbon atoms (e.g., methoxy, ethoxy, butoxy), an aryloxy group (e.g., phenoxy), an aralkyloxy group (e.g., benzyloxy), an aliphatic acyloxy group having 1 to 12 carbon atoms (e.g., formyloxy, acetyloxy, propanoyloxy), an amino group or a substituted amino group (e.g., alkylamino, arylamino), or a lower alkyl group having 1 to 6 carbon atoms, provided that no more than one of the three R 2 groups is alkyl, and it is an organic group.

[0029] The silane monomer may include an ethylenically unsaturated hydrocarbyl group such as vinyl, allyl, isopropenyl, butenyl, cyclohexenyl, or gamma (meth)acryloxyallyl group, and a hydrolyzable group such as, for example, a hydrocarbyloxy, hydrocarbylcarbonyloxy, or hydrocarbylamino group. The hydrolyzable group may include methoxy, ethoxy, formyloxy, acetoxy, propionyloxy, and alkyl or arylamino groups. Examples of silane monomers include vinyltrimethoxysilane (VTMS), vinyltriethoxysilane (VTES), vinyltriacetoxysilane, and gamma-(meth)acryloxypropyltrimethoxysilane. In relation to structure (I), for VTMS, x = 0, R1 = hydrogen, and R 2 = methoxy, for VTES, x = 0, R 1 = hydrogen, and R 2 = ethoxy, and for vinyltriacetoxysilane, x = 0, R 1 = H, and R 2 = acetoxy. The silane monomer may include methacryloxypropyltrimethoxysilane.

[0030] The silane-functionalized polymer has a glass transition temperature of 0 °C to 40 °C when measured according to ASTM D7028. For example, the glass transition temperature of the silane-functionalized polymer is 0 °C or higher, or 5 °C or higher, or 10 °C or higher, or 15 °C or higher, or 20 °C or higher, or 25 °C or higher, or 30 °C or higher, or 35 °C or higher when measured according to ASTM D7028, and at the same time, 40 °C or lower, or 35 °C or lower, 30 °C or lower, or 25 °C or lower, or 20 °C or lower, or 15 °C or lower, or 10 °C or lower, or 5 °C or lower.

[0031] The seed coating composition may include 1 wt% to 30 wt% of the silane-functionalized polymer based on the total weight of the seed coating composition. For example, the seed coating formulation may include 1 wt% or more, or 2 wt% or more, or 4 wt% or more, or 6 wt% or more, or 8 wt% or more, or 10 wt% or more, or 12 wt% or more, or 14 wt% or more, or 16 wt% or more, or 18 wt% or more, or 20 wt% or more, or 22 wt% or more, or 24 wt% or more, or 26 wt% or more, or 28 wt% or more of the silane-functionalized polymer based on the total weight of the seed coating composition, while at the same time, 30 wt% or lower, or 28 wt% or lower, or 26 wt% or lower, or 24 wt% or lower, or 22 wt% or lower, or 20 wt% or lower, or 18 wt% or lower, or 16 wt% or lower, or 14 wt% or lower, or 12 wt% or lower, or 10 wt% or lower, or 8 wt% or lower, or 6 wt% or lower, or 4 wt% or lower, or 2 wt% or lower of the silane-functionalized polymer.

[0032] Polydimethylsiloxane The seed coating composition contains polydimethylsiloxane. PDMS has a CAS number of 9016-00-6. PDMS has a weight average molecular weight of 500,000 g / mol or more, or 600,000 g / mol or more, or 700,000 g / mol or more, or 800,000 g / mol or more, or 900,000 g / mol or more, or 1,000,000 g / mol or more, or 1,100,000 g / mol or more, or 1,200,000 g / mol or more, or 1,300,000 g / mol or more, or 1,400,000 g / mol or more, or 1,500,000 g / mol or more, or 1,600,000 g / mol or more, or 1,700,000 g / mol or more, or 1,800,000 g / mol or more, or 1,900,000 g / mol or more, or 2,000,000 g / mol or more, or 2,100,000 g / mol or more, or 2,200,000 g / mol or more, or 2,300,000 g / mol or more, or 2,400,000 g / mol or more, while at the same time having a weight average molecular weight of 2,500,000 g / mol or less, or 2,400,000 g / mol or less, or 2,300,000 g / mol or less, or 2,200,000 g / mol or less, or 2,100,000 g / mol or less, or 2,000,000 g / mol or less, or 1,900,000 g / mol or less, or 1,800,000 g / mol or less, or 1,700,000 g / mol or less, or 1,600,000 g / mol or less, or 1,500,000 g / mol or less, or 1,400,000 g / mol or less, or 1,300,000 g / mol or less, or 1,200,000 g / mol or less, or 1,100,000 g / mol or less, or 1,000,000 g / mol or less, or 900,000 g / mol or less, or 800,000 g / mol or less, or 700,000 g / mol or less, or 600,000 g / mol or less as measured according to gel permeation chromatography as described below.

[0033] The seed coating composition may contain 0.1% to 6% by weight of PDMS based on the total weight of the seed coating composition. For example, the seed coating composition may contain 0.1% by weight or more, or 0.2% by weight or more, or 0.4% by weight or more, or 0.6% by weight or more, or 0.8% by weight or more, or 1.0% by weight or more, or 1.2% by weight or more, or 1.4% by weight or more, or 1.6% by weight or more, or 1.8% by weight or more, or 2.0% by weight or more, or 2.2% by weight or more, or 2.4% by weight or more, or 2.6% by weight or more, or 2.8% by weight or more, or 3.0% by weight or more, or 3.2% by weight or more, or 3.4% by weight or more, or 3.6% by weight or more, or 3.8% by weight or more, or 4.0% by weight or more, or 4.2% by weight or more, or 4.4% by weight or more, or 4.6% by weight or more, or 4.8% by weight or more, or 5.0% by weight or more, or 5.2% by weight or more, or 5.4% by weight or more, or 5.6% by weight or more, or 5.8% by weight or more. On the other hand, at the same time, it may contain 6.0% by weight or less, or 5.8% by weight or less, or 5.6% by weight or less, or 5.4% by weight or less, or 5.2% by weight or less, or 5.0% by weight or less, or 4.8% by weight or less, or 4.6% by weight or less, or 4.4% by weight or less, or 4.2% by weight or less, or 4.0% by weight or less, or 3.8% by weight or less, or 3.6% by weight or less, or 3.4% by weight or less, or 3.2% by weight or less, or 3.0% by weight or less, or 2.8% by weight or less, or 2.6% by weight or less, or 2.4% by weight or less, or 2.2% by weight or less, or 2.0% by weight or less, or 1.8% by weight or less, or 1.6% by weight or less, or 1.4% by weight or less, or 1.2% by weight or less, or 1.0% by weight or less, or 0.8% by weight or less, or 0.6% by weight or less, or 0.4% by weight or less, or 0.2% by weight or less of PDMS.

[0034] The weight ratio between the silane-functionalized polymer and PDMS in the seed coating composition is from 99:1 to 75:25. For example, the weight ratio of the silane-functionalized polymer to PDMS can be 99:1, or 96:4, or 95:5, or 90:10, or 85:15, or 80:20, while at the same time, it can be 75:25, or 80:20, or 85:15, or 90:10, or 95:5, or 96:4. In the example of the aqueous emulsion, the weight ratio between the silane-functionalized polymer and PDMS is measured based on the solids of the emulsion and does not include the weight of the solvent or water.

[0035] Additive The seed coating composition may include one or more additives in addition to the silane-functionalized polymer and PDMS. For example, the seed coating composition may include a cryoprotectant, a thickener, an antifoaming agent, a pigment, a preservative, a pH adjuster, a coalescing agent, a stabilizer, an active ingredient, and / or combinations thereof. Exemplary cryoprotectants include dihydric alcohols such as ethylene glycol and propylene glycol. The seed coating composition may include a cryoprotectant in an amount of 0.5 wt% to 30 wt% based on the total weight of the seed coating composition. Exemplary thickeners include polysaccharides such as xanthan gum, ram gum, locust bean gum, carrageenan, or welan gum; synthetic polymers such as sodium polyacrylate; semi-synthetic polysaccharides such as carboxymethyl cellulose; mineral fine powders such as magnesium aluminum silicate, smectite, bentonite, hectorite, or fumed silica, or alumina sol. The seed coating composition may include an active ingredient in an amount of 1.0 wt% to 50.0 wt% based on the total weight of the seed coating composition. Examples of active ingredients include pesticides (e.g., thiamethoxam, abamectin, fenobucarb, isoprocarb, chlorfluazuron, chlorpyrifos, fipronil, clothianidin, spinetoram, spinosad, dinotefuran, methoxyphenoside, etofenprox, ethiprole, acephate, benfuracarb, monocrotophos, silafluofen, imidacloprid, etc.), fertilizers, and / or combinations thereof. Exemplary coalescing agents include dipropylene glycol monobutyl ether, [(butoxymethylethoxy)methyl ethoxy]propan-1-ol, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; esters of isobutyric acid with 2,2,4-trimethyl-1,3-pentanediol, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, other coalescing agents, and / or combinations thereof.

[0036] Coated seeds An aqueous emulsion - state seed coating composition is applied to the outer surface of seeds to form coated seeds. The exterior of the seed can be the pericarp, seed coat, endosperm, or other surface to which the seed coating composition adheres. The seed coating composition can be applied to various types of seeds. For example, the seeds can be cereals (e.g., wheat, rye, rice, corn (corn kernels), barley, sorghum, triticale, millet), fruits, vegetables, legumes or other types of seeds.

[0037] Production method The seed coating composition in the form of an aqueous emulsion is applied to the seeds to form coated seeds. Forming the coated seeds can start with the step of forming a silane - functionalized polymer first. The silane - functionalized polymer can be an emulsion in a latex disposed in a carrier solvent / fluid and / or a dry powder. The formation of the silane - functionalized polymer can be carried out according to the description provided below for the method of forming the silane - functionalized polymer. Next, a step of combining a polydimethylsiloxane having a weight - average molecular weight of 500,000 g / mol or more, as measured by gel permeation chromatography, with the silane - functionalized polymer to form the seed coating composition is carried out. The PDMS can be in the form of an emulsion in a latex disposed in a carrier solvent / fluid and / or a dry powder. Additives (including active ingredients) can be added to the seed coating composition before, during, or after the combination of the PDMS and the silane - functionalized polymer. Next, a step of applying the seed coating composition to the seeds is carried out. The seed coating composition can be applied directly to the seeds (e.g., by spraying) and / or the seeds can be mixed with the coating composition and then taken out. After applying the seed coating composition to the seeds, the seed coating composition is dried to form a solid embodiment of the seed coating composition on the coated seeds.

Examples

[0038] Test method Wear rate: The wear rate of the seed coating composition is determined according to the following procedure. 15 g of coated corn seeds are placed in a 90 ml polyethylene plastic container. The container is fixed to a KS 501 Shaker manufactured by IKA products, Staufen, Germany and shaken for 15 minutes at a speed of 280 revolutions per minute. After shaking, high performance liquid chromatography (HPLC) ultraviolet detection measurement is performed. The column used for the measurement is an Agilent Eclipse XDB-C18 (2.1 * 50 mm, 1.8 μm) column, the detector is a DAD (UV absorbance at 280 nm), the solvents used are water and acetonitrile, and the target material is thiamethoxam (THM). After shaking, the coated corn seeds are transferred to another new 90 ml polyethylene container, and the dropped coating (i.e., from shaking) remains in the original 90 ml polyethylene container. A 40 ml solvent mixture (acetonitrile (ACN): H2O (0.1% H3PO4) = 4:1) is introduced into both containers. Both containers are first vortexed and then sonicated for 1 hour and then shaken overnight on a KS 501 Shaker. The samples are left to stand for at least 30 minutes before testing. 0.5 ml of the supernatant from the new 90 ml container is transferred to a 20 ml glass vial and about 12 ml of extraction solvent is added to dilute the sample. The sample is then shaken, 1 ml of the supernatant is taken out, filtered through a 0.22 μm polytetrafluoroethylene membrane, and then analyzed by HPLC. Using these samples, the residual thiamethoxam ("m1") on the corn seeds after shaking is calculated. 1 ml of the solution is taken directly from the original 90 ml container, filtered through a 0.22 μm polytetrafluoroethylene membrane, and then analyzed by HPLC. Using these samples, the thiamethoxam ("m2") dropped during shaking is calculated. The wear rate is calculated by Equation 1, and each wear rate is the average of three repeated samples. Wear rate (%) = m2 / (m1 + m2) * 100% Equation 1

[0039] Water resistance: The water resistance of Examples 1 to 4 and Comparative Examples 1 to 5 of the present invention is determined by placing each example in a Petri dish having sufficient water to immerse the seeds. The examples are left for 24 hours and visually observed after 24 hours. The water resistance is classified into three grades (i.e., good, medium, and poor). Good water resistance means that there is no coloring in the water after immersing the coated seeds in water for 24 hours, while medium and poor indicate that incrementally more water is colored due to the seed coating composition dissolving in the water.

[0040] Germination: The germination test is carried out in accordance with GB / T3543.4 - 1995, titled Rules for agricultural seed testing - Germination Test. In this process, 200 qualified corn seeds are divided into four groups. Two seed germination papers cover the bottom of a plastic tray. One group of seeds (50 seeds / group) is dispersed on the germination paper, then the seeds are covered with another germination paper, and both germination papers are moistened. The plastic tray is covered and stored in a place without lighting. During the test, the seeds are checked daily. Seeds dead from smut are removed and the germination paper is moistened again. The number of germinated seeds is counted on the 4th and 7th days. The germination rate is the average of the four groups of seeds tested.

[0041] Flowability: 25 g of the coated seeds are introduced into a glass tube with an inner diameter of 3 cm and sealed with a cap. Then, the direction of this tube is reversed. Acceptable flowability means that all of the coated seeds flow down in 1 second, while unacceptable flowability means that all or part of the coated seeds remain at the upper part of the glass tube for more than 2 seconds.

[0042] Molecular weight: The weight average molecular weight (Mw) of polydimethylsiloxane is measured according to "Gel Permeation Chromatography" (GPC) performed on a VISCOTEK™ GPC Max using triple detection capabilities. The VISCOTEK™ TDA305 unit is equipped with a differential refractometer, an on-line differential pressure viscometer, and low angle light scattering (LALS: detection angles of 7° and 90°). The mobile phase is high performance liquid chromatography grade toluene. The columns are two PL Gel Mixed C (7.5 * 300 mm, 5 μm particle size) from Varian and a Varian PL Gel Guard column (7.5 * 300 mm), with a 5 fraction injection volume, a flow rate of 1 mL / min, and a run time of 37 minutes. The temperature of the columns and the detector is 40°C. The software used is Omnisec 4.6.1 from VISCOTEK™. The detector is calibrated by injecting a narrow polystyrene standard of known concentration (Mw 68,100 g / mol). Accurate run parameters are verified by using a narrow molecular weight distribution polystyrene standard (PS71K). The molecular weight average must be within a Statistical Process Control (SPC) chart to verify the calibration of the detector. Typical GPC3 precision and accuracy (depending on the increment of refractive index) are approximately 2 - 3%.

[0043] Material The coalescing agent is 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate and is commercially available as Texanol™ coalescing agent from The Eastman Chemical Company, Kingsport, Tennessee.

[0044] The PDMS is an aqueous emulsion of polydimethylsiloxane having a weight average molecular weight of 569,000 g / mol and 80 wt% solids. The PDMS is available from The Dow Chemical Company, Midland, Michigan.

[0045] Seeds: The seeds coated with the seed coating composition were Zhengdan 958 maize hybrid seeds commercially available from the Food and Crop Research Institute, Henan Academy of Agricultural Sciences.

[0046] Silane-functionalized polymer (SSA): SSA is prepared according to the following instructions. A monomer emulsion (ME1) is formed from 670 grams (g) of deionized water, 22.5 g of a fatty alcohol polyglycol ether sulfate sodium salt emulsifier (commercially available as DISPONIL™ FES 993 emulsifier (FES 993)), 825 g of butyl acrylate (BA), 345 g of methyl methacrylate (MMA), 300 g of styrene (ST), 30 g of methacrylic acid (MAA), and 21.70 g of vinyltrimethylsiloxane. 750 g of FES and 5.77 g of FES are added to a 5-liter four-necked flask equipped with a mechanical stirrer, reflux condenser, thermocouple, and inlets for the monomer emulsion and initiator solution. The contents of the flask are heated to 82°C. A 76.3 g seed portion of ME1 is added to the flask, followed by an initiator solution consisting of 10 g of deionized water and 3.75 g of sodium persulfate. The seed portion and initiator solution are rinsed into the flask with deionized water. The polymerization of the seed portion is monitored by the thermocouple, and when the temperature of the reaction mixture reaches a peak, while controlling the reactor temperature at 85°C, the remaining ME1 and a second initiator solution consisting of 200 g of deionized water, 0.75 g of sodium persulfate, and 10.5 g of sodium carbonate are fed monotonically to the reactor over 150 minutes. After the feeding is complete, deionized water is used to rinse ME1 and the initiator solution into the flask, and the reactor is held at 85°C for 10 minutes. The reactor is cooled to 80°C, then a solution of 0.02 g of ferrous sulfate heptahydrate and 0.02 g of tetrasodium ethylenediaminetetraacetate in 5 g of deionized water is added to the flask and rinsed with deionized water. The residual monomer in the reaction mixture is polymerized by feeding a solution of 4 g of z-butyl hydroperoxide in 20 g of deionized water. Next, a solution of 2.2 g of isoascorbic acid in 20 g of deionized water is added to the flask over 20 minutes while cooling the reaction mixture to 55°C.After the supply is completed, the reaction mixture is cooled to 30 °C and neutralized to pH 8 using an ammonium hydroxide solution. Once neutralized, a solution consisting of 0.36 g of KATHON™ LX1400 preservative, 21.73 g of FES, and 8.19 g of deionized water is added to the flask. The resulting latex is filtered to remove the coagulum. The measured solids of the resulting latex are 46.0%. The SSA has a glass transition temperature of 0 °C to 40 °C when measured according to ASTM D7028.

[0047] Active ingredient dispersion: The active ingredient dispersion (AID) is formed from the materials in Table 1.

[0048] [Table 1]

[0049] The AID is formed by combining water, propylene glycol, TERGITOL™ wetting agent, DOWFAX™ dispersant, and POWERBLOX™ dispersant in a stainless steel jar of Geruisi SMJ-2-180 sand mirror and mixing them together until completely dissolved. Then, XIAMETER™ antifoaming agent is added to form a solution. Thiamethoxam and magnesium aluminometasilicate are added to the solution and first mixed with a glass rod, then mixed at 4,000 rpm for 5 minutes with an IKA T25 digital high-speed homogenizer to form a uniform slurry. Then, 72 g of grinding beads (Φ = 0.8 - 1.0 mm) are added to the slurry. The slurry is stirred for 4 hours. After grinding, the pesticide formulation is filtered through a 100-mesh strainer to remove the beads and large thiamethoxam particles to obtain the initial formulation. Color paste and xanthan gum are added to the formulation and mixed at 4,000 rpm for 15 minutes using a high-speed homogenizer to form the AID.

[0050] Preparation of samples Comparative example (「CE」) 1 is uncoated seeds. CE2 - 5 and inventive examples (「IE」) 1 - 4 of the present invention are prepared by combining AID, water, 0.4 wt% of a fusing agent, a silane-functionalized polymer emulsion, and a PDMS emulsion in the indicated amounts to form a seed coating composition, and then applying the examples to the seeds. 1 gram of the seed coating composition is added to a 200 milliliter (「ml」) plastic bottle together with 50 g of corn seeds. The plastic bottle is immediately capped. Next, the plastic bottle is shaken by hand for 1 minute at a frequency of 2 times per second to ensure that all the corn seeds are coated with the seed coating composition. After shaking, the corn seeds are poured onto a release paper and dried overnight.

[0051] Results Table 2 provides the compositions of IE1 - 4 and CE1 - 5, as well as the measured values of the different tests performed. The weight percentages provided in Table 2 for SSA and PDMS represent the weight of the emulsion added based on the total weight of the seed coating composition. 「NM」 in Table 2 indicates that the value was not measured.

[0052]

Table 2

[0053] As can be seen from Table 2, an increase in the dosage of PDMS in the seed coating composition reduces the wear rate. For example, IE1 to IE4 containing 0.38 wt% to 0.94 wt% of the PDMS emulsion dramatically reduce the wear rate compared to CE2 to CE4. Regarding CE5, it can be seen that the addition of too much PDMS has an adverse effect on seed germination. IE2 demonstrates that the use of a silane-functionalized polymer in combination with PDMS does not adversely affect the water resistance of the seed coating composition or the fluidity of the coated seeds. Thus, the seed coating composition enables a wear rate of less than 8%, achieves a seed germination rate of 85% or more while satisfying the water resistance and fluidity characteristics. (Aspect) (Aspect 1) A seed coating composition comprising: A silane-functionalized polymer that is acrylate-based; and A polydimethylsiloxane having a weight average molecular weight of 500,000 g / mol or more as measured according to gel permeation chromatography, the seed coating composition. (Aspect 2) The seed coating composition according to Aspect 1, wherein the silane-functionalized polymer comprises units derived from a silane monomer selected from the group consisting of vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, and combinations thereof. (Aspect 3) The seed coating composition according to Aspect 2, wherein the silane-functionalized polymer comprises units derived from butyl acrylate, methyl methacrylate, methacrylic acid, and styrene. (Aspect 4) The seed coating composition according to Aspect 1, wherein the polydimethylsiloxane has a weight average molecular weight of 500,000 g / mol to 2,500,000 g / mol as measured according to gel permeation chromatography. (Aspect 5) The seed coating composition according to Aspect 1, wherein the silane-functionalized polymer has a glass transition temperature of 0°C to 40°C as measured according to ASTM D7028. (Aspect 6) The seed coating composition according to Aspect 1, wherein the weight ratio of the silane-functionalized polymer to the polydimethylsiloxane in the seed coating composition is 99:1 to 75:25. (Aspect 7) The seed coating composition according to Aspect 6, wherein the weight ratio of the silane-functionalized polymer to the polydimethylsiloxane in the seed coating composition is 96:4 to 85:15. (Aspect 8) The seed coating composition according to Aspect 1, further comprising water, wherein the silane-functionalized polymer, the polydimethylsiloxane, and the water form an emulsion. (Aspect 9) A coated seed comprising: A seed defining an outer surface; and The seed coating composition according to Aspect 1 in contact with the outer surface of the seed. (Aspect 10) A method of forming a coated seed, the method comprising: Forming a silane-functionalized polymer that is acrylate-based; When measured by gel permeation chromatography, combining a polydimethylsiloxane having a weight average molecular weight of 500,000 g / mol or more with the silane-functionalized polymer to form a seed coating composition; Applying the seed coating composition to seeds to form coated seeds. A method comprising these steps.

Claims

1. A seed coating composition comprising: a silane-functionalized polymer that is acrylate-based; and a polydimethylsiloxane having a weight average molecular weight of 500,000 g / mol or more and 1,000,000 g / mol or less as measured according to gel permeation chromatography, wherein the seed coating composition contains 0.38% to 0.94% by weight of the silane-functionalized polymer based on the total weight of the seed coating composition.

2. The seed coating composition according to claim 1, wherein the silane-functionalized polymer contains units derived from silane monomers selected from the group consisting of vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, and combinations thereof.

3. The seed coating composition according to claim 2, wherein the silane-functionalized polymer contains units derived from butyl acrylate, methyl methacrylate, methacrylic acid, and styrene.

4. The seed coating composition according to claim 1, wherein the polydimethylsiloxane has a weight average molecular weight of 500,000 g / mol to 900,000 g / mol as measured according to gel permeation chromatography.

5. The seed coating composition according to claim 1, wherein the silane-functionalized polymer has a glass transition temperature of 0°C to 40°C as measured according to ASTM D7028.

6. The seed coating composition according to claim 1, wherein the weight ratio of the silane-functionalized polymer to the polydimethylsiloxane in the seed coating composition is 94:6 to 85:

15.

7. The seed coating composition according to claim 6, wherein the weight ratio of the silane-functionalized polymer to the polydimethylsiloxane in the seed coating composition is 92:8 to 90:

10.

8. The seed coating composition according to claim 1, further comprising water, wherein the silane-functionalized polymer, the polydimethylsiloxane, and the water form an emulsion.

9. A coated seed comprising: a seed defining an outer surface; and the seed coating composition according to claim 1 in contact with the outer surface of the seed.

10. A method of forming a coated seed comprising: A step of forming a silane-functionalized polymer that is acrylate-based; A step of forming a seed coating composition by combining a polydimethylsiloxane having a weight average molecular weight of 500,000 g / mol or more and 1,000,000 g / mol or less, when measured by gel permeation chromatography, with the silane-functionalized polymer; A method comprising a step of applying the seed coating composition to seeds to form coated seeds, wherein the seed coating composition contains 0.38% to 0.94% by weight of the silane-functionalized polymer based on the total weight of the seed coating composition.

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