Recommendations for the use of metallic color powder dispersants
Metallic color powder dispersants are important additives used to improve the dispersion performance
of metallic color powders in media (such as coatings, inks, plastics, etc.). Reasonable use can effectively
improve the gloss, hiding power and stability of metallic effect products. The following are recommendations
for the use of metallic color powder dispersants:
1. Choose a suitable dispersant
Consider the type of medium: Different application media (such as water-based, solvent-based, powder
coatings, etc.) have different requirements for dispersants. In water-based systems, it is necessary to select a
dispersant with good hydrophilicity, while in solvent-based systems, it is necessary to select a corresponding
dispersant according to the polarity of the solvent. For example, in water-based metallic coatings, a dispersant
with good water solubility and strong adsorption capacity for metallic color powder should be selected to ensure
that the metallic color powder can be evenly dispersed in water.
Matching metallic color powders: Metallic color powders of different types and particle sizes also have different
requirements for dispersants. For metallic color powders with smaller particle sizes, it is necessary to select a
dispersant with strong adsorption capacity and good steric hindrance effect to prevent the agglomeration of color
powder particles. For example, nano-scale aluminum powder requires a special dispersant to ensure its stable
dispersion.
Evaluate the performance of dispersants: Understand the performance indicators of dispersants such as dispersing
efficiency, stability, temperature resistance, and chemical resistance. Dispersants with high dispersing efficiency can
make the metal color powder reach a good dispersion state in a shorter time; dispersants with good stability can
ensure that the metal color powder does not settle or agglomerate during storage and use of the product.
2. Determine the appropriate addition amount
Conduct a small test experiment: Before formal use, a small test experiment should be carried out to determine
the optimal addition amount of the dispersant. Generally, you can start with a lower addition amount and gradually
increase it to observe the dispersion effect of the metal color powder and the performance changes of the product.
For example, when preparing metallic ink, you can first add a certain amount of dispersant, observe the viscosity,
glossiness and metallic effect of the ink after stirring, and then adjust the amount of dispersant appropriately until
the best effect is achieved.
Consider the balance between cost and performance: Although increasing the amount of dispersant added may
improve the dispersion effect, it will also increase the cost. Therefore, it is necessary to minimize the use of
dispersants while ensuring product performance to achieve a balance between cost and performance.
3. Optimize the dispersion process
Stirring speed and time: The appropriate stirring speed and time are essential for the dispersion of metallic color
powder. If the stirring speed is too low, it will not provide enough shear force to disperse the metal color powder;
if the stirring speed is too high, it may generate too much heat, resulting in dispersant failure or oxidation of the
metal color powder and other adverse reactions. Generally speaking, the appropriate stirring speed and time
should be selected according to the characteristics of the dispersing equipment and the metal color powder. For
example, when using a high-speed disperser, the stirring speed can be controlled at 1000-3000 rpm, and the
stirring time is 15-30 minutes.
Dispersing equipment selection: Different dispersing equipment has different dispersing principles and effects.
Common dispersing equipment includes high-speed dispersers, sand mills, ball mills, etc. For metal color powders
with larger particle sizes, you can first use a high-speed disperser for pre-dispersion, and then use a sand mill or ball
mill for fine dispersion to obtain better dispersion effect.
Temperature control: During the dispersion process, temperature control is also very important. Excessive temperature
may cause the dispersant to decompose or the metal color powder to undergo physical and chemical changes, thereby
affecting the dispersion effect and product quality. Generally speaking, the dispersion temperature should be controlled
within the tolerance range of the dispersant and the metal color powder.
4. Pay attention to the compatibility of dispersants with other additives
Avoid interactions: Metallic color powder dispersants may interact with other additives (such as leveling agents, defoamers,
thickeners, etc.), affecting the performance of the product. Therefore, when using dispersants, it is necessary to consider
their compatibility with other additives. Small-scale experiments can be used to evaluate the performance changes of
dispersants after mixing with other additives, such as viscosity, stability, gloss, etc.
Adjust the order of addition: If there are compatibility issues between dispersants and other additives, you can try to
adjust their order of addition. Generally speaking, the dispersant should be mixed evenly with the metallic color powder
before adding other additives.
5. Storage and use precautions
Storage conditions: Metallic color powder dispersants should be stored in a cool, dry, well-ventilated place, avoiding
direct sunlight and high temperature environment. At the same time, pay attention to sealed storage to prevent the
dispersant from moisture or volatilization.
Safety of use: When using dispersants, you should comply with relevant safety operating procedures and wear personal
protective equipment such as gloves and goggles. If it accidentally comes into contact with skin or eyes, rinse immediately
with plenty of water and seek medical attention.
