What Are the Common Issues with Oil Suspension Concentrates?
An OD formulation is essentially a multiphase dispersion system-solid particles dispersed in an oil phase-which inherently faces interfacial instability.
01 Particle growth
Fresh surfaces generated during milling tend to cause particles to re-approach and re-agglomerate.
02 Solid Sedimentation
Flocculation occurs during storage, particle size increases, and the system becomes coarser.
03 Crystallization of polar active ingredients
Highly polar actives have poor compatibility with the oil phase, making them more prone to precipitation or crystal growth.
04 Flocculation upon dilution
The concentrate may appear stable, but upon dilution with water, it can become destabilized again.
Many OD formulation issues appear on the surface as formulation instability, but essentially, they stem from poor interfacial control.
A dispersant is not just about "keeping particles apart"-it performs a complete interfacial regulation system:
Adsorbs onto particles, rapidly covering freshly generated surfaces.
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Isolates particles, forming a protective layer to prevent re-aggregation.
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Stabilizes the system, enhancing compatibility between particles and the oil phase.
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Aids redispersion, ensuring rapid and uniform dispersion upon dilution with water.
Thus, a dispersant is not simply a dispersing agent; it is the full process of adsorption-isolation-stabilization-redispersion.
Not All OD Formulations Face the Same Challenge.
Different systems have different challenges, and correspondingly, have different dispersant strategies.
High-content OD systems
Challenges: difficult discharge, short shelf life, poor flow over time
Requirements: good flow during milling, extended shelf life, stable dispersion in high-content systems
Highly polar active ingredient systems
Challenges: prone to crystallization, coarsening, and difficult to grind fine.
Requirements: multi-site adsorption, crystallization inhibition, improved grinding efficiency.
Systems requiring both concentrate stability and redispersion upon dilution
Challenges: concentrate is stable, but dilution destabilizes it
Requirements: stable in oil phase, strong adsorption, good redispersion in water
Selecting a dispersant is not just about "whether it can disperse"-it is about whether it can resolve the core contradiction of your specific system.
SP-OD499H is Sinvo's solution for high-content OD formulations.
Keywords: Polyacrylate-type, super-dispersant, broad compatibility, high-content systems.
A polyacrylate-type super-dispersant for oil suspension systems, suitable for vegetable oils and their derivatives, including methyl ester and ethyl ester systems, as well as mineral oil-based high-content systems.
Best suited for: High-content OD systems using vegetable oil, methyl/ethyl esters, or mineral oil as carriers.
If your challenge is "flowability or viscosity reduction over time in high-content OD," prioritize SP-OD499H.
SP-OD274 is designed for highly polar active ingredient systems.
Keywords: Comb-shaped structure, multi-site adsorption, crystallization inhibition
A novel high-molecular-weight surfactant with a comb-shaped structure formed by copolymerization of unsaturated monomers. Its well-solvated side chains help maintain compatibility between particles and the continuous phase; high charge density and side chains enhance multi-site adsorption on particle surfaces.
It effectively inhibits crystallization of highly polar actives in oil carriers, reduces particle size, and improves formulation stability.
Best suited for: Highly polar active systems and systems prone to crystallization.
If your challenge is "preparing OD with highly polar actives" or "crystallization," prioritize SP-OD274.
Dispersant SP-OD 488 is a synergistic solution for both concentrate stability and redispersion upon dilution.
Keywords: Special polycarboxylate, oil-phase compatibility, firm adsorption, secondary dispersion stability, improved grinding efficiency.
A specially structured polycarboxylate dispersant for OD, produced via controlled polymerization. Its long carbon-chain side groups offer good compatibility with methyl oleate or vegetable oils; benzene or heterocyclic side chains provide strong adsorption onto particle surfaces; and polyoxyethylene ether and carboxylate side chains enhance secondary dispersion stability in water.
It effectively balances storage stability in low-to-medium-content OD formulations with redispersion performance upon dilution, and significantly improves grinding efficiency.
Best suited for: Difficult-to-grind systems, low-to-medium-content methyl ester or vegetable oil systems, and formulations that require both storage stability and application-performance stability.
If your challenge is "achieving both physical stability and good dilution performance in low-to-medium-content formulations" or "difficult grinding," prioritize Dispersant SP-OD 488.
How to Choose Among These Three Adjuvants?
First, identify what your system cares about most.
If you are concerned about highly polar active ingredient or crystallization inhibition, choose SP-OD274
If you are concerned about long-term stability of high-content OD, choose SP-OD499H.
If you are concerned about concentrate stability, secondary redispersion upon dilution, and improved grinding efficiency, choose Dispersant SP-OD 488.
There is no "universal dispersant"-only a dispersant solution that better fits your specific formulation system.