Water-dispersible herbicidal granule composition

Abstract

The present invention relates to a water-dispersible herbicidal granule composition with a biphasic architecture designed for improved field performance and storage stability. The granules comprise a core containing Pyroxasulfone (75.0–90.0% w / w) and a shell architecture incorporating functional excipients. These include a dual binder system of hydroxypropyl cellulose (0.3–2.5%) and polyvinylpyrrolidone (0.3–2.0%), crosslinked sodium carboxymethyl cellulose as a disintegrant, calcium lignosulfonate (1.0–4.0%) as a structural dispersant, and hydrophobic fumed silica (0.3–3.0%) for anti-caking and enhanced flow. Additionally, hydrogenated castor oil ethoxylate (0.2–1.0%) is embedded to boost spreading and surface interaction. The composition demonstrates excellent physical integrity, rapid water dispersion, and resistance to humidity-induced degradation. It enables uniform herbicide delivery, improved adherence to crop surfaces, and consistent efficacy under varying environmental conditions, making it ideal for modern agricultural applications.

Description

TECHNICAL FIELD

[0001] The present invention relates to agrochemical formulations, and more particularly to water-dispersible herbicidal granule compositions comprising Pyroxasulfone. More specifically, the present invention pertains to a biphasic granule architecture that offers enhanced dispersion, mechanical integrity, and resistance to caking under humid conditions, along with compositions prepared using optimized low-shear granulation and controlled drying techniques.BACKGROUND

[0002] Conventional herbicidal formulations, especially those containing Pyroxasulfone, are commonly delivered as emulsifiable concentrates or suspension concentrates. However, these liquid-based formulations are prone to issues such as phase separation, solvent volatility, and flammability, which raise concerns related to safety, environmental impact, and storage stability. Solid formulations such as water-dispersible granules (WDGs) were developed to address these concerns. Yet, existing WDGs suffer from several drawbacks, including slow dispersion, inadequate disintegration in hard or cold water, poor mechanical integrity during transportation, and significant caking under high humidity cond. Furthermore, many granule formulations fail to achieve consistent flowability and uniform application, especially when stored for extended periods in tropical climates

[0003] Traditionally, emulsifiable concentrates (ECs) and suspension concentrates (SCs) were the predominant modes of delivering herbicides like Pyroxasulfone. These formulations, although effective in delivering the active ingredient, suffer from several inherent limitations. ECs, for instance, rely heavily on organic solvents, which not only pose toxicity and flammability risks but also contribute to volatile organic compound (VOC) emissions, thereby impacting human health and the environment. SCs, on the other hand, often experience sedimentation, instability during storage, and poor re-dispersibility, particularly when exposed to sub-optimal conditions such as cold temperatures or prolonged shelf life.

[0004] To overcome these challenges, water-dispersible granules (WDGs) were introduced as a safer and more stable alternative. WDGs eliminate the need for organic solvents and offer improved handling, reduced packaging waste, and ease of transportation. However, despite their advantages, conventional WDG formulations of Pyroxasulfone still exhibit several critical shortcomings that hinder their field performance and storage reliability.

[0005] One of the major drawbacks of existing granule formulations is poor dispersion behavior in water. In practical field use, granules must rapidly disintegrate and disperse upon dilution in spray tanks to ensure uniform distribution of the herbicide. However, many current formulations fail to achieve complete and consistent dispersion, particularly in cold or hard water conditions. The use of sub-optimal disintegrants or binders often results in clumping, slow wetting, or incomplete release of the active ingredient, negatively affecting spray coverage and herbicidal efficacy.

[0006] Another significant limitation is the mechanical fragility of the granules during packaging, transportation, and field handling. Granules with weak internal structures may break down under mechanical stress, generating fines or dust that not only reduce the active ingredient concentration but also pose inhalation hazards and complicate metering during application. Conversely, over-compacted granules can become too hard, reducing their ability to disperse quickly in water.

[0007] Caking and flowability are further concerns, especially in regions with high humidity. Many conventional granules are prone to moisture absorption, which leads to caking, lump formation, and bridging in storage containers or application equipment. The absence of effective surface treatments or moisture barriers in existing formulations allows ambient humidity to compromise the integrity and usability of the product. This not only affects the granule's shelf life but also creates operational inefficiencies for farmers and applicators.

[0008] Additionally, foaming during tank mixing is a persistent problem in existing granule formulations. Excessive foam generation can cause delays, reduce tank capacity, and interfere with the accurate mixing of the herbicide solution. While some compositions attempt to address this with surfactants or antifoaming agents, these are often inadequately integrated into the formulation and do not provide consistent results across variable environmental conditions.

[0009] Furthermore, existing formulations do not incorporate advanced granule engineering approaches such as core-shell architecture, which can enable functional layering of ingredients to tailor performance characteristics. Most granules rely on homogeneous blending of excipients, resulting in limited control over the release profile, structural integrity, and interfacial behavior of the granules in water. This lack of granule-level design limits their adaptability under diverse agronomic and climatic conditions.

[0010] There is, therefore, an unmet need for an advanced water-dispersible granule formulation of Pyroxasulfone that overcomes these limitations by offering faster and uniform dispersion, improved mechanical strength, reduced caking, better flowability, and resistance to foaming, all while being suitable for large-scale manufacturing and long-term storage.

[0011] Thus, to overcome the limitations associated with conventional formulations, the present invention provides a novel biphasic granule architecture with a Pyroxasulfone-loaded core and a multi-functional shell. The granules are engineered using a dual binder system, embedded disintegrants, surface dispersants, and post-treatment agents to achieve rapid dispersion, mechanical strength, reduced foaming, and anti-caking behavior under humid storage. The method of preparation involving low-shear wet granulation and controlled drying further ensures preservation of binder structure and uniformity in granule morphology. This integrated approach resolves the shortcomings of conventional granules and enhances overall field performance and storage stability.OBJECTIVE OF THE INVENTION

[0012] The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available techniques and processes.

[0013] Accordingly, the present invention pertains to agrochemical formulations, and more particularly to water-dispersible herbicidal granule compositions comprising Pyroxasulfone. More specifically, the present invention pertains to a biphasic granule architecture that offers enhanced dispersion, mechanical integrity, and resistance to caking under humid conditions, along with compositions prepared using optimized low-shear granulation and controlled drying techniques.

[0014] Yet one more object of the present invention has been developed as a water-dispersible herbicidal granule composition to provide a water-dispersible herbicidal granule composition comprising Pyroxasulfone with enhanced physical and dispersive properties.

[0015] Therefore, the current invention successfully overcoming all the above-discussed shortcomings present in the art.

[0016] The main object of the present invention is to develop a water-dispersible herbicidal granule composition to provide a biphasic granule structure with a functional core and shell, offering improved granule integrity and environmental resistance.

[0017] The main object of the present invention is to develop a water-dispersible herbicidal granule composition to incorporate a dual binder system and embedded disintegrants for faster and uniform dispersion in water.

[0018] The main object of the present invention is to develop a water-dispersible herbicidal granule composition to improve flowability and reduce caking by integrating hydrophobic silica and surface-active agents.

[0019] Another object of the present invention is to develop a water-dispersible herbicidal granule composition to offer resistance against humidity-induced degradation and preserve performance during long-term storage.

[0020] The main object of the present invention is to develop a water-dispersible herbicidal granule composition to employ a low-shear granulation method with controlled drying to retain the semi-crystalline structure of the binder matrix and optimize granule morphology.

[0021] The main object of the present invention is to develop a water-dispersible herbicidal granule composition to minimize foaming during tank mixing and enhance spreading and adhesion on crop foliage.

[0022] The main object of the present invention is to develop a water-dispersible herbicidal granule composition to provide a scalable and industrially viable method for preparing high-performance herbicidal granules.

[0023] How the foregoing objects are achieved will be clear from the following brief description. In this context, it is clarified that the description provided is non-limiting and is only by way of explanation. Other objects and advantages of the invention will become apparent as the foregoing description proceeds, taken together with the accompanying drawings and the appended claims.SUMMARY

[0024] This summary is provided to introduce a selection of concepts in a simplified format that is further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended for determining the scope of the invention.

[0025] According to an aspect of the present invention relates to a water-dispersible herbicidal granule composition is provided, having a biphasic architecture comprising a core and a shell. The core comprises Pyroxasulfone in an amount ranging from 75.0% to 90.0% by weight. Surrounding the core is a multifunctional shell comprising several functional components. The shell includes a dual binder system consisting of hydroxypropyl cellulose (HPC) in a concentration range of 0.3% to 2.5% and polyvinylpyrrolidone (PVP) in a range of 0.3% to 2.0%, which together impart structural cohesion and facilitate controlled disintegration. A crosslinked sodium carboxymethyl cellulose (Na-CMC) is uniformly embedded throughout the granule matrix to act as a structural disintegrant, promoting rapid and consistent dispersion upon contact with water. Additionally, calcium lignosulfonate is included in a range of 1.0% to 4.0% and is applied as a structural dispersant that coats at least a portion of the granule surface to enhance wettability and initial dispersion. To improve flowability and prevent moisture-induced bridging, hydrophobic fumed silica is deposited externally in a range of 0.3% to 3.0%, acting as a moisture barrier. Further, a hydrogenated castor oil ethoxylate (HCOE) is incorporated in a concentration of 0.2% to 1.0% to improve surface interaction during application, aiding in better adhesion and spreading of the active on crop foliage. Collectively, the composition ensures rapid and uniform dispersion in water, enhanced physical integrity under pressure, improved resistance to humidity-induced caking, and stable performance during storage and field use, even in tropical and humid environments

[0026] In an aspect of the invention, the granules are produced using a low-shear wet granulation process followed by controlled drying at 50°C to 60°C to preserve binder structure and optimize granule morphology.

[0027] In an aspect of the invention, outer surface of the granule is post-treated with a combination of functional agents to enhance performance during storage and application. A silicone-based non-ionic antifoaming agent is applied in the range of 0.05% to 0.3% by weight to effectively suppress foam formation during tank mixing, thereby ensuring smoother and more efficient preparation of spray solutions. Additionally, a layer of hydrophobic fumed silica is deposited in the range of 0.3% to 3.0% by weight, which acts as a moisture barrier and flow-enhancing agent. This dual surface treatment significantly reduces the tendency of the granules to cake under humid storage conditions, improves flowability through dispensing and application equipment, and ensures consistent delivery of the herbicide in diverse environmental settings.

[0028] In an aspect of the invention, the disintegrant Na-CMC is crosslinked in a range of 0.5 to 2.5% and uniformly distributed throughout the granule matrix to facilitate water penetration and granule breakage within 2 minutes of water contact.

[0029] In an aspect of the invention, the calcium lignosulfonate forms a semi-permeable dispersant coating around the core, reducing hygroscopicity and providing protection against ambient humidity.

[0030] In an aspect of the invention, sorbitan monooleate (Span 80) in a range of 0.5 to 2.0% is embedded in the granule matrix, as an internal wetting agent, enhancing surface spreading upon application.

[0031] In an aspect of the invention, the granule size ranges from 300 to 1000 microns, exhibiting a moisture content of less than 2% and a friability of less than 5%.

[0032] In an aspect of the invention, further comprising a natural colorant such as chlorophyllin coated over the outer shell for visual identification and antioxidative properties.

[0033] Accordingly, a method for preparing a water-dispersible herbicidal granule composition comprises several sequential steps to ensure structural integrity, uniform dispersion, and enhanced field performance. Initially, Pyroxasulfone in the range of 75.0% to 90.0% by weight is blended with inert excipients including hydroxypropyl cellulose (HPC), polyvinylpyrrolidone (PVP), crosslinked sodium carboxymethyl cellulose (Na-CMC), calcium lignosulfonate, sorbitan monooleate (Span 80), hydrogenated castor oil ethoxylate (HCOE), and microcrystalline cellulose to form a uniform dry mixture. This dry blend is then subjected to wet granulation using an aqueous binder solution containing HPC and PVP, resulting in the formation of structurally stable granules with an embedded Na-CMC disintegrant and the initial development of a shell layer. The wet granules are subsequently dried at a controlled temperature between 50°C and 60°C until the moisture content is reduced to below 2%, thereby preserving the integrity of the binder matrix and maintaining the desired core-shell morphology. Following drying, the granules are gently post-blended with hydrophobic fumed silica in the range of 0.3% to 3.0% and a silicone-based non-ionic antifoaming agent in the range of 0.05% to 0.3% to coat the granule surface. This surface treatment improves flowability, reduces the risk of caking under humid conditions, and controls foam generation during tank mixing. The granules are then sieved to obtain a particle size distribution in the range of 300 to 1000 microns. Finally, the finished product is packaged in moisture-proof containers under humidity-controlled conditions to preserve the physical and dispersive properties of the granules. The inclusion of hydrogenated castor oil ethoxylate in the formulation further enhances spreading and adhesion of the active ingredient on foliar surfaces upon field application.

[0034] In an aspect of the invention, the drying step preserves the semi-crystalline structure of the binders, thereby improving granule integrity and controlled water uptake.

[0035] To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated herein, and constitute a part of this disclosure, illustrate exemplary embodiments of the disclosed methods and devices in which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Some drawings may indicate the components using block diagrams and may not represent the internal circuitry of each component. It will be appreciated by those skilled in the art that disclosure of such drawings includes disclosure of electrical components, electronic components or circuitry commonly used to implement such components.Figure 1 illustrates a bar graph of a water-dispersible herbicidal granule composition having a biphasic architecture, in accordance with an embodiment of the invention; and Figure 2 illustrates a bar graph of the Comparison of Traditional vs. water-dispersible herbicidal granule composition of Pyroxasulfone 85% WG.Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein. DETAILED DESCRIPTION OF EMBODIMENTS

[0037] For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

[0038] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the invention and are not intended to be restrictive thereof.

[0039] Reference throughout this specification to "an aspect", "another aspect" or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0040] The terms "comprise", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

[0042] The terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.

[0043] The terms "having", "comprising", "including", and variations thereof signify the presence of a component.

[0044] Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

[0045] Herbicides are essential agrochemicals used extensively in modern agriculture to control weed populations that negatively impact crop yield and farm productivity. Among the various formulations available, water-dispersible granules (WDGs) have emerged as a preferred option due to their ease of handling, storage stability, reduced dust generation, and improved safety profiles. However, traditional WDGs still face several challenges that affect their overall field performance, such as poor dispersion, foaming during tank mixing, susceptibility to caking under humid conditions, and limited adhesion or spreading ability on plant surfaces. These issues not only reduce the efficacy of the active ingredient but also cause operational inconveniences for farmers.

[0046] Pyroxasulfone, a pre-emergent herbicide known for its broad-spectrum efficacy against annual grasses and broadleaf weeds, offers excellent control when applied uniformly. However, the formulation of Pyroxasulfone into effective, stable, and easy-to-use granules that maintain performance under varying storage and environmental conditions remains a challenge. Conventional Pyroxasulfone granules often exhibit poor dispersibility, low water penetration rates, and undesirable physical changes during storage, especially under high humidity. These drawbacks highlight the need for a novel formulation that maintains herbicide potency while enhancing user convenience and environmental stability.

[0047] In this context, the present invention provides a uniquely designed biphasic water-dispersible granule composition that incorporates a Pyroxasulfone-loaded core and a multifunctional shell. This shell integrates a dual binder system, structural disintegrants, dispersants, wetting agents, and post-treatment components to ensure rapid and uniform dispersion in water, strong mechanical integrity, and enhanced performance in humid storage. The granules are engineered using a low-shear wet granulation technique followed by controlled drying to preserve structural morphology and binder function.

[0048] This invention addresses the unmet needs in herbicide delivery systems by providing a formulation that overcomes the key limitations of conventional WDGs. The incorporation of synergistic components such as hydrogenated castor oil ethoxylate, crosslinked sodium carboxymethyl cellulose, and surface-modifying agents ensures enhanced field efficacy, improved ease of application, and better environmental tolerance. The resulting product delivers superior performance in real-world agricultural settings, reducing waste, improving crop coverage, and ensuring the longevity of the formulation under diverse conditions.

[0049] The invention discloses a water-dispersible herbicidal granule composition with a biphasic architecture, comprising a core and a shell. The core includes Pyroxasulfone as the active ingredient in the range of 75.0% to 90.0% by weight. Pyroxasulfone serves as a selective herbicide that provides broad-spectrum control of weeds during the pre-emergent stage. The high loading of Pyroxasulfone ensures potent activity while maintaining compact granule size and consistent performance.

[0050] Surrounding the core is a shell composed of multiple functional layers. A dual binder system is employed, consisting of hydroxypropyl cellulose (HPC) in the range of 0.3% to 2.5% and polyvinylpyrrolidone (PVP) in the range of 0.3% to 2.0%. These binders act synergistically to form a cohesive shell structure, improving granule integrity and moisture resistance. The shell also includes crosslinked sodium carboxymethyl cellulose (Na-CMC) as a structural disintegrant uniformly embedded within the matrix. This disintegrant facilitates rapid water penetration and disintegration of the granule within 2 minutes of contact with water.

[0051] To enhance dispersion properties and reduce hygroscopicity, calcium lignosulfonate in the range of 1.0% to 4.0% is incorporated as a surface dispersant. It forms a semi-permeable coating around the granule, enabling controlled water diffusion and stabilizing the surface during humid storage. Additionally, a hydrophobic fumed silica layer in the range of 0.3% to 3.0% is externally deposited to prevent moisture bridging, reduce clumping, and improve flowability. Hydrogenated castor oil ethoxylate (HCOE) in the range of 0.2% to 1.0% is added to promote surface spreading during application, enhancing foliar adhesion and uniform herbicide coverage.

[0052] To further optimize performance, the outer surface of the granule is post-treated with a silicone-based non-ionic antifoaming agent in the range of 0.05% to 0.3%. This surface treatment mitigates foaming during tank mixing, ensuring smoother preparation and spraying. The hydrophobic fumed silica also serves a secondary function in this outer layer, contributing to anti-caking and flow-enhancing effects. The integration of these components results in a granule that maintains structural integrity under pressure, disperses rapidly in water, and resists caking and degradation under humid conditions.

[0053] The method of preparation includes several critical steps that preserve the efficacy and integrity of the granules. Initially, Pyroxasulfone is blended with inert excipients including HPC, PVP, Na-CMC, calcium lignosulfonate, sorbitan monooleate (Span 80), HCOE, and microcrystalline cellulose to form a uniform dry mixture. This mixture is then subjected to low-shear wet granulation using an aqueous solution of HPC and PVP, promoting granule agglomeration while embedding the disintegrants and binders into a stable matrix. The granules are then dried at controlled temperatures between 50°C and 60°C to ensure that moisture content is reduced below 2%, preserving the semi-crystalline binder structure and granule morphology.

[0054] Post-processing includes gentle tumbling of the dried granules with hydrophobic fumed silica and a silicone-based antifoaming agent to uniformly coat the surface. This post-treatment enhances flowability, minimizes moisture absorption, and prevents foaming. The granules are then sieved to obtain a uniform particle size ranging from 300 to 1000 microns. Finally, they are packaged in moisture-proof containers under humidity-controlled conditions, preserving their physical and dispersive properties over extended storage periods.

[0055] The resultant granule composition demonstrates superior performance in agricultural applications. The rapid disintegration and dispersion allow for quick tank mixing and consistent field application. The enhanced spreading and adhesion of the herbicide on foliage lead to better weed control and minimized runoff. The structural integrity and anti-caking behavior ensure long-term stability, even under challenging storage conditions. Furthermore, the inclusion of chlorophyllin as a natural colorant not only facilitates visual identification but also offers antioxidative benefits that improve shelf life.Table 1: Exemplary composition for Water-Dispersible Herbicidal Granule

[0056] The above-mentioned Table 1, provides a comprehensive overview of the formulation components, their functional roles, physical forms, and concentration ranges in the water-dispersible herbicidal granule composition. At the core of the formulation lies Pyroxasulfone, a pre-emergent herbicide presents in the range of 75.0% to 90.0% by weight, which acts as the primary active ingredient responsible for inhibiting weed growth. This high loading ensures potent herbicidal activity while minimizing the need for multiple applications in the field. To effectively convert this active compound into a granule form that disperses readily in water, the formulation integrates a biphasic shell composed of functional excipients.

[0057] The shell architecture is built upon a dual binder system comprising Hydroxypropyl Cellulose (HPC) and Polyvinylpyrrolidone (PVP), present in the range of 0.3% to 2.5% and 0.3% to 2.0%, respectively. These binders serve a dual purpose-providing mechanical strength during granule formation and maintaining granule cohesion during storage and handling. Embedded within the matrix is crosslinked Sodium Carboxymethyl Cellulose (Na-CMC) in the range of 0.5% to 2.5%, which functions as a disintegrant. Upon contact with water, Na-CMC swells and rapidly breaks apart the granules, enabling the quick release and dispersion of the active compound within two minutes, ensuring user convenience and field efficacy.

[0058] The external layer of the granule incorporates Calcium Lignosulfonate, used in the range of 1.0% to 4.0%, which serves as a structural dispersant. This lignosulfonate coating provides a semi-permeable barrier that reduces hygroscopicity and enhances dispersion, making the product more stable under varying humidity levels. Additionally, Hydrophobic Fumed Silica, applied post-drying in the range of 0.3% to 3.0%, acts as an anti-caking agent and flow enhancer. This silica coating minimizes moisture bridging between granules, which is essential for maintaining free-flowing behavior in humid environments.

[0059] To further improve the application performance, the formulation includes Hydrogenated Castor Oil Ethoxylate (HCOE) at concentrations ranging from 0.2% to 1.0%. HCOE enhances the spreadability and adhesion of the herbicide on crop foliage, improving the delivery and efficacy of the active ingredient. Additionally, Sorbitan Monooleate (Span 80), used in the range of 0.5% to 2.0%, is included as a wetting agent within the granule matrix to promote rapid water uptake and even dispersion. Microcrystalline Cellulose is used as a structural bulking agent in a quantity-sufficient amount to ensure granule uniformity and mechanical stability during processing.

[0060] To enhance tank-mixing compatibility, the surface of the granules is post-treated with a silicone-based non-ionic antifoaming agent at levels between 0.05% and 0.3%. This component minimizes foam formation during mixing and spraying operations, contributing to a smoother application experience for farmers. The formulation may also include a natural colorant such as chlorophyllin in trace amounts, not only for product differentiation and visual identification but also to provide antioxidative properties that further stabilize the active ingredient.

[0061] The physical properties of the granules are carefully controlled to meet field requirements. The granule size ranges between 300 and 1000 microns, which ensures compatibility with conventional spreaders and sprayers. The final product exhibits a moisture content of less than 2%, promoting shelf-life stability, and friability under 5%, indicating robustness during transport and handling. The granules are dried at 50°C to 60°C, a temperature range optimized to retain the semi-crystalline structure of the binders and preserve the core-shell morphology. Finally, the product is packaged in moisture-proof containers under humidity-controlled conditions, ensuring that the formulation maintains its dispersive and physical integrity throughout storage and transportation.

[0062] Referring to Figure 1, which showcases the percentage weight range of each functional component in the proposed granule matrix, highlighting the dominant presence of Pyroxasulfone as the active herbicidal ingredient, followed by the supporting roles of binders, dispersants, disintegrants, and surface-modifying agents.

[0063] Overall, the table effectively consolidates the compositional and functional elements of the invention into a structured format that underscores the synergy between the components. It highlights how each ingredient is purposefully selected and quantitatively optimized to achieve a balance of stability, rapid dispersion, application efficacy, and resistance to environmental stressors. This structured design provides a scalable and reliable solution for modern herbicide delivery in agricultural practices.Table 2: Side-by-Side Comparison: Traditional vs. Proposed More Novel Pyroxasulfone 85% WG

[0064] Table 2 presents a detailed side-by-side comparison between the conventional formulation of Pyroxasulfone 85% WG and the proposed more novel formulation, highlighting improvements in functional performance, environmental safety, stability, and user convenience. Each component is analyzed based on its role in the composition, and key advancements are underlined to emphasize the advantages introduced by the novel approach. The active herbicide, Pyroxasulfone (≥97%), remains the core ingredient in both formulations. While the traditional version maintains a fixed concentration of 85%, the proposed formulation provides a flexible range of 75% to 90%, allowing manufacturers to optimize for cost, application efficiency, and performance based on specific market needs or environmental conditions. This flexibility improves scalability and customization without compromising efficacy.

[0065] In terms of dispersant selection, the conventional formulation uses sodium lignosulfonate, which is more hygroscopic and thus vulnerable to moisture-induced degradation during storage. The proposed formulation replaces this with calcium lignosulfonate at similar levels, which exhibits reduced hygroscopicity, contributing to enhanced storage stability and reduced caking, particularly in humid conditions. For dual-function dispersant and binder agents, polycarboxylate ether copolymers are replaced by hydroxypropyl cellulose (HPC). This substitution improves the biodegradability, safety profile, and structural strength of the granules. HPC's cellulose-based origin also aligns with sustainable agricultural practices and provides better mechanical cohesion during granulation and application.

[0066] The wetting agent in the traditional formulation, dioctyl sulfosuccinate sodium salt (DOSS), is substituted with sorbitan monooleate (Span 80) in the novel formulation. Span 80 demonstrates lower foaming tendencies and superior stability in hard water, ensuring more consistent performance during tank mixing and improving ease of spraying across variable water qualities in different agricultural regions. In the binder category, polyvinyl alcohol (PVA) is replaced by polyvinylpyrrolidone (PVP). PVP offers additional benefits such as film-forming ability and improved rain fastness, which helps in maintaining the herbicide's efficacy even after irrigation or rainfall, thus enhancing its reliability in unpredictable weather conditions.

[0067] The adjuvant or emulsifier component also undergoes significant enhancement. Soy lecithin in the traditional formulation is replaced with hydrogenated castor oil ethoxylate (HCOE). HCOE provides better surface spreading and adhesion, ensuring the active ingredient remains in contact with leaf surfaces longer, thereby improving uptake and overall herbicidal performance. When it comes to disintegrants, the traditional formulation employs sodium starch glycolate, whereas the novel version uses crosslinked sodium carboxymethyl cellulose (Na-CMC). This new disintegrant exhibits faster and more efficient water-triggered granule breakup, ensuring rapid dispersion and minimizing preparation time for the end user.

[0068] For antifoaming, the novel formulation utilizes a silicone-based non-ionic antifoam in place of polydimethylsiloxane. This substitution offers improved compatibility across a wider pH and temperature range, reduces visible residues in the tank, and contributes to a cleaner spray solution. To improve flow properties and resistance to caking, hydrophobic fumed silica replaces traditional colloidal silica. This hydrophobic form provides better performance under humid storage, maintaining the granule's flowability and preventing clumping, which is crucial for maintaining operational efficiency during large-scale applications.

[0069] In terms of colorant, the proposed formulation moves toward sustainability by incorporating natural pigments like chlorophyllin, replacing optional synthetic dyes. Apart from aiding in product identification, chlorophyllin may provide antioxidant benefits, helping to stabilize sensitive components within the granule. Lastly, the bulk or filler material, which is undefined in the traditional approach, is clearly addressed in the proposed formulation using microcrystalline cellulose (q.s.). This addition not only helps achieve consistent granule size and structure but also contributes to uniform dispersion and better handling characteristics during packaging and application.

[0070] Referring to Figure 2, compares traditional and proposed formulations of Pyroxasulfone 85% WG across various functional categories. This visual representation underscores the shift towards more efficient, eco-friendly, and performance-enhancing excipients such as calcium lignosulfonate, hydroxypropyl cellulose, and hydrogenated castor oil ethoxylate. The graphs collectively demonstrate the formulation's technical sophistication, improved storage stability, environmental compatibility, and enhanced field performance through optimized ingredient selection and composition.

[0071] In conclusion, the present invention delivers a highly functional herbicidal granule with multiple enhancements over conventional WDGs. By integrating strategic excipients, innovative post-treatment, and a robust preparation method, the formulation addresses critical shortcomings such as poor dispersion, foaming, humidity sensitivity, and inconsistent field performance. This solution enables farmers to achieve better weed control with greater convenience and reliability, making it a valuable advancement in agrochemical technology.

[0072] While certain present preferred embodiments of the invention have been illustrated and described herein, it is to be understood that the invention is not limited thereto. Clearly, the invention may be otherwise variously embodied and practiced within the scope of the following claims.

Claims

1. A water-dispersible herbicidal granule composition having a biphasic architecture comprising: a core comprising Pyroxasulfone in a range of 75.0% to 90.0% by weight, and a shell comprising: i. a dual binder unit consisting of hydroxypropyl cellulose (HPC) in a range of 0.3 to 2.5% and polyvinylpyrrolidone (PVP) in a range of 0.3 to 2.0%; ii. a crosslinked sodium carboxymethyl cellulose (Na-CMC) as a structural disintegrant embedded throughout the granule matrix; iii. a calcium lignosulfonate in a range of 1.0 to 4.0%, as a structural dispersant coating at least a portion of the granule surface; iv. a hydrophobic fumed silica in a range of 0.3 to 3.0%, deposited externally to enhance flowability and prevent moisture bridging, wherein the granules exhibit physical integrity under pressure, rapid dispersion in water, and improved resistance to humidity-induced caking; and v. a hydrogenated castor oil ethoxylate (HCOE) in a range of 0.2% to 1.0%, incorporated to facilitate improved surface interaction during application, wherein the composition enables uniform dispersion in water, enhanced adhesion and spreading on crop foliage, and stable performance under humid storage and field conditions.

2. The water-dispersible herbicidal granule composition as claimed in claim 1, wherein the granules are produced using a low-shear wet granulation process followed by controlled drying at 50°C to 60°C to preserve binder structure and optimize granule morphology.

3. The composition as claimed in claim 1, wherein the outer surface of the granule is post-treated with: - a silicone-based non-ionic antifoaming agent in the range of 0.05% to 0.3% by weight, and - a layer of hydrophobic fumed silica in the range of 0.3% to 3.0%, wherein the combined surface treatment reduces foaming during tank mixing, imparts anti-caking properties, and enhances flowability under humid conditions.

4. The water-dispersible herbicidal granule composition as claimed in claim 1, wherein the disintegrant Na-CMC is crosslinked in a range of 0.5 to 2.5% and uniformly distributed throughout the granule matrix to facilitate water penetration and granule breakage within 2 minutes of water contact.

5. The water-dispersible herbicidal granule composition as claimed in claim 1, wherein the calcium lignosulfonate forms a semi-permeable dispersant coating around the core, reducing hygroscopicity and providing protection against ambient humidity.

6. The water-dispersible herbicidal granule composition as claimed in claim 1, wherein sorbitan monooleate (Span 80) in a range of 0.5 to 2.0% is embedded in the granule matrix, as an internal wetting agent, enhancing surface spreading upon application.

7. The water-dispersible herbicidal granule composition as claimed in claim 1, wherein the granule size ranges from 300 to 1000 microns, exhibiting a moisture content of less than 2% and a friability of less than 5%.

8. The water-dispersible herbicidal granule composition as claimed in claim 1, further comprising a natural colorant such as chlorophyllin coated over the outer shell for visual identification and antioxidative properties.

9. A method for preparing a water-dispersible herbicidal granule composition as claimed in claim 1, the method comprising: - blending Pyroxasulfone in the range of 75.0% to 90.0% by weight with inert excipients including hydroxypropyl cellulose (HPC), polyvinylpyrrolidone (PVP), crosslinked sodium carboxymethyl cellulose (Na-CMC), calcium lignosulfonate, sorbitan monooleate (Span 80), hydrogenated castor oil ethoxylate (HCOE), and microcrystalline cellulose to form a uniform dry mixture; - granulating the dry blend using an aqueous binder solution containing HPC and PVP to form structurally stable granules with embedded Na-CMC disintegrant and initial shell formation; - drying the granules at a controlled temperature between 50°C and 60°C until moisture content is reduced below 2%, thereby preserving binder integrity and core-shell morphology; - post-blending the dried granules with hydrophobic fumed silica in the range of 0.3% to 3.0% and a silicone-based non-ionic antifoaming agent in the range of 0.05% to 0.3% by gentle tumbling, to coat the granule surface and enhance flowability, reduce caking, and control foaming; - sieving the granules to obtain a particle size range of 300 to 1000 microns; and - packaging the granules in moisture-proof containers under humidity-controlled conditions to preserve physical and dispersive properties, wherein the incorporation of hydrogenated castor oil ethoxylate facilitates improved spreading and adhesion of the active ingredient on foliar surfaces upon application.

10. The method as claimed in claim 9, wherein the drying step preserves the semi-crystalline structure of the binders, thereby improving granule integrity and controlled water uptake.