Unlock the key code for using high-pigment carbon black dispersants
High-pigment carbon black dispersants are key additives used to improve the dispersibility of carbon black in the
medium. Their correct use is crucial to improving product performance. The following provides professional
guidance on dispersant selection, usage methods, dosage control, precautions, etc.:
1. Dispersant selection
Matching principle
Select dispersants according to the characteristics of carbon black particle size, specific surface area, surface
functional groups, etc. For example, high specific surface area carbon black requires a dispersant with a strong anchoring
group.
The type of medium determines the type of dispersant: water-based systems select water-based dispersants (such as
polyacrylates), and solvent-based systems select solvent-based dispersants (such as polyurethanes).
Performance verification
Test the viscosity reduction effect, dispersion stability, and blackness enhancement ability of the dispersant through
experiments.
Evaluate the compatibility of the dispersant with the resin and solvent to avoid system instability.
2. Usage method
Pre-dispersion treatment
Add the dispersant to the solvent or resin in proportion and stir at low speed for 10-15 minutes to ensure that the
dispersant is fully dissolved.
It is recommended to use a high-speed disperser (speed 1000-3000rpm) or a sand mill for pre-dispersion.
Carbon black addition
Add carbon black in batches, and the amount added each time should not exceed 20% of the total amount to avoid
agglomeration.
After addition, continue high-speed dispersion for 30-60 minutes until the viscosity of the system is stable.
Post-treatment
Further refine the carbon black particles through grinding equipment (such as three-roller mill, bead mill), and the
recommended particle size is controlled at 100-200nm.
Filter to remove impurities to ensure the purity of the system.
3. Dosage control
Reference dosage
Water-based system: The amount of dispersant is 30%-50% of the mass of carbon black (such as 20% carbon black
addition, the amount of dispersant is 6%-10%).
Solvent-based system: The amount of dispersant is 20%-40% of the mass of carbon black.
Optimization and adjustment
The optimal dosage is determined by rheological testing (such as rotational viscometer), with the lowest viscosity
and no flocculation as the standard.
High-pigment carbon black (such as surface area>200m²/g) requires an appropriate increase in the amount of
dispersant.
4. Precautions
Environmental control
The operating temperature is controlled at 20-35℃ and the humidity is ≤60% to prevent the dispersant from
absorbing moisture and becoming ineffective.
Ensure that the equipment is clean to prevent impurities from affecting the dispersion effect.
Safety regulations
Wear protective equipment to avoid contact with the skin or inhalation of the dispersant.
Dispersants are irritating and need to be stored in a cool and ventilated place away from fire.
Quality inspection
Detect the particle size distribution of the dispersed system (such as using a laser particle size analyzer) to
ensure that D90 is ≤200nm.
Test storage stability (such as 50℃/7 days) to observe whether there is sedimentation or coarsening.
5. Solutions to common problems
Uneven dispersion
Check whether the amount of dispersant is sufficient and increase the pre-dispersion time.
Adjust the parameters of the dispersion equipment to increase the shear force.
The viscosity of the system is too high
Reduce the amount of carbon black added or increase the amount of dispersant.
Optimize the dispersion process and use multi-stage dispersion.
Insufficient blackness
Ensure that the carbon black is fully dispersed to avoid agglomeration.
Choose an optimized combination of high-pigment carbon black and dispersant.
By scientifically selecting dispersants, standardizing operating procedures, and strictly controlling quality,
the dispersion effect of high-pigment carbon black can be significantly improved, thereby optimizing
the performance of the final product.
