Differentiation and Breakthrough in SC and OD Formulations：Innovative Solutions and Strategies from Key Players

Editor's Note: SC and OD formulations have gained rapid growth due to their safety, environmental friendliness and high efficiency benefits. However, there are certain issues in the processing and storage of them, especially the crystal growth and particle size increase etc. These issues cause severe formulation instability over time, ultimately leading to formulation failure. To address these issues, major adjuvant companies introduced a series of innovative solutions, including dispersants, emulsifiers, crystal growth inhibitor, rheology modifiers, and other adjuvants/additives. In the current context of homogenized competition among formulation products, high-load formulations and unique mixture products contribute to highlighting the differentiation of products and  helping companies to enrich their product lines and enhance their overall competitiveness.

SINVOCHEM

SINVOCHEM is committed to researching the entire life cycle delivery of pesticides and providing innovative adjuvant solutions to achieve better efficacy. For SC and OD formulations, SINVOCHEM offers two new dispersants with name: SP-OD499 and SP-SC55.

Long-term stability enhance dispersant SP-OD499 for high loading OD: SP-OD499 is a new macropolymer specially designed for high loading OD. Side chain with N groups, alkyl groups and main chain with macro-molecular, makes it can effectively reduce the viscosity of high loading OD during milling process. Macro-polymer provides steric hindrance to improve the storage stability and effectively inhibits phase separation over time or formation of non-flowable cream.

Crystal growth inhibit dispersant SP-SC55 for SC: SP-SC55, a novel polycarboxylate dispersant includes weak cationic groupsis, with outstanding performance on particle size control for SC formulations such as Pyraclostrobin SC、Buprofezin SC that tend to occur crystallization or particle size growth during storage. SP-SC55 also presents good electrolyte-resistance and enhanced deposition of pesticide droplet on foliar.

Dow Chemical

Dow offers new polycarboxylic dispersants manufactured locally in Asia Pacific region for water-based agrochemical formulations with trade name: POWERBLOX^TM D-787 and POWERBLOX^TM D-737.

POWERBLOX^TM D-737 has well balanced performance and cost effectiveness. It’s universally applied for water-based formulations (SC, ME etc.) and can provide good stabilizing/dispersing functionalities during formulation preparation as well as in formulation storage.

POWERBLOX^TM D-787 has more superior steric hindrance functionality based on the comb-like structure design. It can also provide exceptionally absorption onto varied Active Ingredients surface with lower viscosity as well as improved storage stability. D-787 can be applied for various suspension concentrate formulations especially on high A.I. content formulations.

Together with other innovative solutions and products from Dow, POWERBLOX^TM D-787 and D-737 will enable crop formulators with more differentiated choices and sustainable growth.

Syensqo

Syensqo launched the dispersant polymers Geropon HL4 and Geropon ION5 for the design of complex suspension and flowable concentrate formulations.

Geropon HL4 and Geropon ION5 were confirmed as very efficient dispersants, interestingly, high loadings of actives at reduced dispersant polymer dosage can be achieved for a large range of phytosanitary actives tested. Geropon HL4 prevented crystal growth of challenging actives such as metribuzin, enabling a sharp control on particle size distribution. In addition, in comparison with the benchmark, a better tolerance in the presence of water-soluble electrolytes such as salts of glyphosate was obtained for Geropon ION5, enabling the formulation of complex combos of high ionic strength. The two polymers were also successfully tested in various SC systems (with metazachlor, chlorothalonil...) and FS formulations (with imidacloprid and thiamethoxam) confirming their superior dispersion performance and high versatility. In addition, the two dispersant grades present high solid content compared to benchmark, ranging from 40 to 45%wt, and represent therefore perfect solutions for systems with very limited formulation space, with the need to introduce low levels of dispersants.

Stepan

Stepan offers a wide range of solutions for most of the components used in OD that can help farmers and formulators address their challenges.

Dispersion Media

Stepan Agricultural Solutions offers a wide range of sustainably advantaged methyl esters that are naturally derived from vegetable oil, including STEPAN® 108，STEPAN C-42，STEPAN C-65，STEPOSOL® ME，STEPOSOL ROE-W  and STEPOSOL SB-W.

Emulsifiers

Stepan offers a wide range of anionic and nonionic emulsifiers for OD formulations. For anionic emulsifiers, our NINATE® Series of linear or branched calcium dodecyl benzene sulfonates are available in a 100% dry form or in liquid variants of various concentrations in different solvents. For nonionic emulsifiers, alkoxylates with varying moles of ethylene oxide are available. These alkoxylates use different hydrophobes including castor oil, synthetic alcohol, fatty acid, sorbitan esters and alkyl phenols. Apart from these, a range of ethylene oxide-propylene oxide block co-polymers of butanol, polypropylene glycol and trystyrenated phenols are also available.

Stepan has developed an optimized emulsifier blend, STEPGROW® AB 1005, that is designed to work with various methyl esters and varying water hardness. The required dosage is only about 10% of oil loading in the formulation. Apart from Stepan’s methyl esters, it is expected to emulsify various C12-C18 methyl esters, derived from different feedstocks. 

Dispersants

STEPFAC™ 8181 PT3K is a ~100% actives phosphate ester with a defined mono- to di-ester ratio. This optimized ratio makes it a suitable oil dispersant in a formulation, then as an aqueous dispersant upon dilution in water. Without this optimized mono- to di-ester ratio, formulators may need to use separate oil and aqueous dispersants with different chemistries. This complicates the formulation development process especially with respect to formulation and dilution stability.

Rheology modifiers

Stepan also has a ready-to-use, self-emulsifying and easy-to-handle rheology modifier – STEPGROW® RM-1002. It is a proprietary blend containing surfactants and other non-reactive ingredients. STEPGROW RM-1002 does not need any special activation process by longer mixing or heating for better dissolution. This provides an advantage over other rheology modifiers such as modified clays, fumed silica and polyamides. 

Ingevity

Crystal growth is one of the biggest challenges in agrochemical suspension concentrate (SC) formulations. The most important component is choosing a high-performing dispersant that can provide strong coverage of active ingredient particle surface. Secondly, adding a crystal growth inhibitor to lower active ingredient solubility, or introducing competing ″impurity″ to slow down active ingredient molecule re-adsorption process can dramatically reduce crystal growth. Lastly, using combination of non-ionic and anionic surfactant blend and appropriate amount of thickener can also help stabilize the system.

Dispersant

Most important component for crystal growth control is the dispersant.

- High-performing dispersant can provide good milling efficiency, good coverage and strong adsorption to active surface

- It will provide robustness for the whole system upon temperature fluctuation

- It will prevent settlement of actives in wide temperature range

All these properties are essential to ensure your formulation to have stability and low crystal growth.

Ingevity offers high-performing kraft lignosulfonate dispersants for strong active coverage for wide range of different actives. The dispersants suggested for SC formulations are:Reax 907,  Reax 910, Reax 1425E, Polyfon H, AltaBio 200

Crystal growth inhibitor

High DOS kraft lignosulfonates can be used as additive in low use rate to reduce crystal growth by

- Introducing competing ″impurity″ to slow down active deposition process on existing particle bare surface

- Suppressing active solubility in water by increasing ionic strength.

Ingevity high DOS/low Mw lignosulfonate recommended as crystal growth inhibitor:Polyfon F, Reax 100M

Other solutions

- Non-ionic/anionic surfactant blend: reduce/slow down crystal growth thorough

• Tighter and stronger coverage

• Quick surface coverage

• Slowing down active molecule re-adsorb process to the particle surface.

- Salt: suppress the active solubility in water, especially for high temperature induced crystal growth, but the use rate needs to be evaluated to ensure not harming performance of the whole system.

- Thickener: restrict molecular motion in solution and reduce particle agglomeration.

Ultimately, different formulations will face different technical difficulties and require different co-formulant systems to obtain the best formulations. 

Levaco Chemicals

LUCRAMUL® AG 497, a high-performance co-dispersant developed by Levaco Chemicals, is a high-efficient co-dispersant and crystal growth inhibitor for use in high content SC, having excellent water dispersibility and storage stability. Levaco Chemicals focuses on the development of permeative synergist, where the product, LUCRAMUL® AG 104&108, showed high permeability during testing.  

If you'd like to share your company's solutions or have any promotion demands, please contact Grace Yuan: grace@agropages.com