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Home / News / Industry News / fx Carbon Black and Titanium Dioxide Not Dispersing Well? Here Is How to Fix It
Industry News
Dispersant Technology · Coatings & Inks · DH-5033
In coating and ink production, whether pigments can be fully wetted and stably dispersed directly affects system viscosity, hue, gloss, and storage stability. Titanium dioxide, lithopone, iron oxide, and carbon black, if inter-particle agglomeration remains present during dispersion, easily cause an unstable system state.
This influence does not only show during the production stage — it can further be reflected in the final coating film, for example as uneven surface, gloss reduction, or colour non-uniformity. Improving the wetting and dispersion state of pigments is therefore an important step in enhancing coating film performance.
TiO₂
Lithopone
Iron Oxide
Carbon Black
Common Problems
Insufficient Pigment Wetting
Inadequate bonding between pigment particles and resin easily forms agglomeration, affecting subsequent grinding and dispersion efficiency.
Hue and Viscosity Fluctuation
Unstable pigment dispersion causes changes in system viscosity and reduced colour consistency between batches.
Settling and Re-Coarsening in Storage
Pigments not maintaining a stable dispersed state readily develop settling, caking, or particle re-agglomeration after extended storage.
Gloss Loss and Surface Defects in Film
Non-uniform pigment distribution affects coating film surface state — uneven surface and localised gloss loss may appear, ultimately affecting coating appearance.
Limitations of Traditional Improvement Approaches
When facing insufficient pigment dispersion, some formulations attempt improvement by extending grinding time or increasing dispersion speed. However, if the wetting compatibility between pigment and resin is itself insufficient, purely increasing mechanical action can often only solve part of the problem, and may also increase production time and energy consumption.
It is therefore more effective to start from the interfacial state between pigment and resin — using an appropriate dispersing additive to improve pigment wetting and stable dispersion — helping to reduce agglomeration and keep the system in a more uniform state, rather than relying solely on equipment shear intensity.
DH-5033: Pigment Dispersant with Special Pigment-Affinity Groups
DH-5033 is a polymeric dispersant with special pigment-affinity groups, applicable for titanium dioxide, lithopone, iron oxide, carbon black, and other pigment and filler systems. By improving the wetting and affinity between pigment particles and the polymer, it helps pigments disperse more uniformly in the system, thereby improving system viscosity stability and hue consistency.
In coating applications, DH-5033 can help improve the pigment dispersion state, reduce settling, flooding, re-coarsening, and caking problems, while helping to improve coating film surface state and gloss performance. For paints that have already developed swelling or gelation, post-addition is also possible depending on the system condition — stirring or grinding can help improve the paint state.
Additionally, this product can reduce the system baking temperature to some degree, and provides auxiliary improvement for coating film water resistance, hardness, adhesion, and anti-ageing performance.
Dispersion Stability
More uniform distribution reduces viscosity fluctuation and hue inconsistency between batches
Storage Performance
Reduces settling, re-coarsening, and caking tendency during extended storage
Film Surface Quality
Improves coating film surface state and gloss performance
Auxiliary Film Properties
Contributes to water resistance, hardness, adhesion, and anti-ageing performance
Baking Temperature
Helps reduce system baking temperature — supports more energy-efficient production
Post-Addition Capability
Can be post-added to paints with swelling or gelation, helping to restore system state
Summary
Pigment dispersion does not only affect grinding efficiency — it further determines system viscosity stability, hue consistency, and final coating film appearance. For titanium dioxide, iron oxide, carbon black, and other pigments, improving wetting and dispersion state helps reduce settling, re-coarsening, and flooding. Appropriate use of a brightening dispersant can improve dispersion stability and coating film performance starting from the pigment interface.
Frequently Asked Questions
Can DH-5033 be used for both organic and inorganic pigments?
Yes — its special pigment-affinity group structure is applicable for both inorganic pigments (titanium dioxide, iron oxide, lithopone) and carbon black. For organic pigments with specific surface chemistry, a trial evaluation at the target pigment and resin system is recommended to confirm performance and optimal dosage.
If the paint has already developed swelling or gelation, how should DH-5033 be post-added?
For paints with swelling or gelation, DH-5033 can be added while stirring at low to moderate speed. After addition, continued stirring or light grinding helps distribute the dispersant uniformly through the system and allows the dispersant to begin stabilising the pigment surface. The improvement effect depends on the degree of swelling and the system composition — a trial on the affected batch is recommended before treating the full production quantity.
Why does poor pigment dispersion affect the baking temperature of the coating?
Poorly dispersed pigments create local concentration gradients and interface inconsistencies in the system that can affect the cure kinetics of the resin network. DH-5033's improvement of the pigment-resin interface compatibility contributes to a more homogeneous cure environment that, in some systems, allows equivalent crosslinking to be achieved at a lower temperature.
