Whats should pay attention when purchasing pigment dispersant liquid ?

1. System Compatibility (Primary)

Confirm the system type: distinguish between pure water-based, water-based acrylic, solvent-based, alcohol-soluble, and UV systems. Dispersants from different systems must not be mixed, as mismatches directly lead to flocculation, coarsening, floating coloration, and loss of gloss.

Compatible pigment type

Inorganic pigments (iron oxide, titanium white): Focus on anionic dispersants, relying on charge repulsion;

Organic pigments / carbon black: Prefer high-molecular-weight block copolymer dispersants, with strong adsorption of anchor groups on organic particles, anti-flocculation, and enhanced tinting strength.

pH Applicable Range: For water-based coating inks, the pH of dispersants must be checked for compatibility with the resin system. Significant pH deviations can lead to system thickening and precipitation.

Resin compatibility: Must match the resin and emulsion used. Poor compatibility can lead to film dullness, cratering, and haze.

2. Key Technical Indicators (Focus on Liquid Dispersants)

Solid content: a core metric for liquid products. Do not focus solely on unit price. For the same active ingredient, low-solid products have lower procurement costs but contain less effective material, requiring higher addition rates and resulting in higher overall costs.
Viscosity: The inherent viscosity of the product, which should not be excessively high to facilitate dispersion during feeding. Additionally, attention should be paid to viscosity reduction capability: for the same pigment loading, lower viscosity of the color paste indicates better dispersion efficiency, making it suitable for high-concentration color paste production.
solvent / carrier component

Water-based: Check for the presence of solvents such as ethylene glycol or propylene glycol; pay attention to VOC content when exporting to the EU;

Solvent-based: Identify the carrier solvent (xylene, butyl ester, etc.) to avoid conflicts with your system’s solvent.

Water-resistant, weather-resistant, and migration-resistant

Topcoat and outdoor coatings: Avoid small-molecule dispersants, as they can easily leach out, leading to poor water resistance and loss of gloss; prefer high-molecular-weight types;
Printing ink: Focus on migration resistance to prevent color bleeding and undercolor trapping.

Foam tendency: Some liquid dispersants inherently produce foam, which may cause pinholes or bubbles in coatings and inks. Select standard/low-foam variants based on the process requirements.