WO 2012/108873 Al 16 August 2012 (16.08.2012) P O P C T
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(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (10) International Publication Number (43) International Publication Date WO 2012/108873 Al 16 August 2012 (16.08.2012) P O P C T (51) International Patent Classification: AO, AT, AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ, A 43/68 (2006.01) CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM, DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, (21) International Application Number: HR, HU, ID, IL, IN, IS, JP, KE, KG, KM, KN, KP, KR, PCT/US201 1/024457 KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD, ME, (22) International Filing Date: MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, 11 February 201 1 ( 11.02.201 1) OM, PE, PG, PH, PL, PT, RO, RS, RU, SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, (25) Filing Language: English UA, UG, US, UZ, VC, VN, ZA, ZM, ZW. (26) Publication Language: English (84) Designated States (unless otherwise indicated, for every (71) Applicant (for all designated States except US) : DOW kind of regional protection available): ARIPO (BW, GH, AGROSCIENCES LLC [US/US]; 9330 Zionsville Road, GM, KE, LR, LS, MW, MZ, NA, SD, SL, SZ, TZ, UG, Indianapolis, IN 46268 (US). ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, (72) Inventors; and EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, LV, (75) Inventors/Applicants (for US only): HOPKINS, Derek MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, [GB/NZ]; 503 Mangorei Road, New Plymouth, 43 12 (NZ). TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, KEENEY, Franklin [US/US]; 12304 Windsor Drive, Car- ML, MR, NE, SN, TD, TG). mel, IN 46033 (US). LIU, Lei [US/US]; 1501 Brookmill Declarations under Rule 4.17 : Court, Carmel, IN 46032 (US). QIN, Kuide [CN/US]; 13 179 Lamana Place, Westfield, IN 46074 (US). — as to applicant's entitlement to apply for and be granted a patent (Rule 4.1 7(H)) (74) Agent: ARNETT, Charles; Dow AgroSciences LLC, 9330 Zionsville Rd, Indianapolis, Indiana 46268 (US). Published: (81) Designated States (unless otherwise indicated, for every — with international search report (Art. 21(3)) kind of national protection available): AE, AG, AL, AM, 00 o00 o (54) Title: STABLE AGROCHEMICAL OIL DISPERSIONS (57) Abstract: The present disclosure relates to the use of dibenzylidene sorbitol or derivatives of dibenzylidene sorbitol as rheology additives to provide stability to oil dispersion formulations of agrochemical active ingredients. STABLE AGROCHEMICAL OIL DISPERSIONS FIELD OF THE INVENTION [1] This disclosure concerns the use of dibenzylidene sorbitol (DBS) or chemical derivatives of DBS as rheology modifiers useful in preparing stable oil dispersion (OD) compositions of agrochemical products. BACKGROUND AND SUMMARY OF THE INVENTION [2] An agrochemical active ingredient, such as a herbicide, insecticide, or fungicide, or a herbicide safener, can rarely be used in its originally manufactured form. Agrochemical products generally consist of two parts, the active ingredient and the co-formulants or inert ingredients combined together in a formulation. The combination of these two parts into the final product is conducted with two primary goals in mind: (1) maintaining the stability of the product during storage and (2) providing an easy and effective way to use the product upon dilution in a carrier such as water or oil, and spray application to an area to be treated. [3] Agrochemical formulations are generally designed based on customer needs and the physiochemical properties of the active ingredient(s), for example, the solubility of the active ingredient in water and other non-aqueous solvents. There are two major categories of formulations, solid formulations and liquid formulations. Liquid formulations include emulsifiable concentrates (EC), suspension concentrates (SC), soluble liquids (SL), liquid flowables (F) and oil dispersions (OD). EC formulations consist of oil-soluble active ingredient(s) dissolved in non-aqueous solvent(s) to which are added emulsifying agents. [4] The basic components of an agricultural OD formulation are the solvent or oil phase and the dispersed solid phase. These basic components may include active ingredients, petroleum or naturally derived solvents, safeners, rheology additives, emulsifiers, dispersants and other co-formulants that help deliver the desired attributes of the product. Rheology additives provide physical stability to the formulation by increasing the viscosity of the liquid phase in order to prevent insoluble active ingredient particles from falling out of suspension and forming a layer at the bottom of the storage container. This phenomenum, known as sedimentation, can result in difficulties in the delivery and use of the product if the sedimented layer of particles forms a hard pack that is difficult to disperse and re-suspend. A related physical instability of liquid formulations is syneresis. Syneresis in an OD formulation is generally measured as the amount of top- clearing due to phase separation. [5] The amount and severity of sedimentation that occurs in an OD formulation over time may be measured with a pourability test. This test is conducted by pouring the OD formulation out of a container in a controlled manner and measuring the amount of the formulation remaining in the container. The pourability value is the per cent by weight of material remaining in the container. [6] Rheology additives used to control sedimentation, also known as thickeners, anti-caking agents, viscosity modifiers or structuring agents, generally provide the increased viscosity to the OD formulation. In addition to increasing the viscosity of the OD formulation, rheology additives have a shear thinning capability that allows the gel network they form to easily breakdown upon application of a small external force. This shear thinning allows the OD formulation to maintain its viscosity and physical stability while at rest, but allows this viscosity to quickly dissipate when external force is applied so that the product can be easily poured or pumped from its container, mixed in a carrier such as water and applied to an area where it is needed. [7] Rheology additives used in products today to add viscosity come in many forms and chemistries. They can be mineral or derived from minerals (e.g., organoclays, fumed silica), swellable polymers (e.g., polyamides or hydrogenated caster oils), associative thickeners which form structures by themselves (e.g., EO/PO block co-polymers), or they can be steric dispersants (e.g., comb polymers such as polyvinylpyrrolidinones or polyacrylates). These rheological or structuring agents provide long term stability when the product is at rest or in storage. [8] Agrochemical products generally have to be diluted and properly dispersed in water prior to application. An emulsifier system may be included in the OD formulation to help disperse the oil-based, water immiscible formulation in water. An emulsifier system commonly includes a mixture of non-ionic and anionic surfactants in order to accommodate variations in water hardness and temperature encountered in various locations. [9] For polar interactions, clays, organoclays such as bentonite, hectorite or gibbsite clays, which are also known as hydrophobically modified clays, hydrogenated castor oils, castor oil derivatives, polyamides, polar, oxidized waxes, and hydrophobized fumed silica may be used as rheology aids in non aqueous solvents. For controlled pigment flocculation in paints, organic sulfates are commonly used. High molecular weight polymers such as ethyl cellulose, cellulose acetobutyrate and man-made polymers such as polyacrylates, polystyrenes and polyisobutylenes may also be used to build viscosity in organic solvents. Finally, soaps such as aluminum stearate and magnesium stearate may be used to build viscosity. [10] Natural clay products are generally layered silicates that can be effective thickeners for a wide range of applications. In order to make them dispersible in non-aqueous solvents, however, the clay surface is usually treated with quaternary ammonium. These modified clays are known as organoclay thickeners. These strongly agglomerated particles need to be wetted first and then separated by shear forces. High shear mixing is desirable for this process. Activators like alcohols can penetrate in between the clay layers and help make them form loose stacks for ease of application. The typical rheology curve of clay particle modified OD formulation shows strong shear-thinning and thixotropic behavior. At low shear stress, the clay structure may show some resistance to the flow. With increasing shear stress, the applied shear force progressively destroys the clay network and the layered clay particles start to move with the flow. When the shear is removed, the clay network reforms and the viscosity builds up again. Depending on the type and origin of the clay products, it is important to know that the rheology building efficiency varies due to the difference in clay particle sizes and shapes. Boehmite clay seems to be more effective in enhancing the rheology properties of a fluid than the other type of clays due to its larger aspect ratio and hence its surface area. [11] The thickening mechanism of hydrogenated castor oils and their derivatives, polyamides and polar, oxidized waxes is based on hydrogen bonding, but these additives may be somewhat sensitive to temperature effects. The procedure of activating hydrogenated caster oil products requires both shear mixing and heat since these products are delivered as micronized powders. Similar to the organo-clays, these micronized powders have to be dispersed into a gel form without complete dissolution in the solvent. The first step is swelling of the crystalline particles by the solvent using shear and heat to provide swollen particles that become fully separated and dispersed.