Water-based dispersants: performance innovators and environmental boosters for coatings and inks
At a time when environmental protection policies are becoming increasingly stringent and consumers'
environmental awareness is increasing, the coatings and inks industry is accelerating its transformation to
water-based. As the core additive for the production of water-based coatings and inks, water-based dispersants
are like a "magic key" that unlocks a new realm of product performance improvement, while also driving the
industry towards green and sustainable development.
1. The working principle of water-based dispersants: the cornerstone of building a stable dispersion system
Water-based dispersants are a type of surfactant designed specifically for water-based systems. Their unique molecular
structure gives them strong dispersing ability. Water-based dispersant molecules usually contain hydrophilic groups
and lipophilic groups. When added to water-based coatings or ink systems, the lipophilic groups will be tightly
adsorbed on the surface of the pigment particles, while the hydrophilic groups will extend into the water.
This unique adsorption method achieves stable dispersion of pigments through two mechanisms. First, many
water-based dispersants will make the surface of pigment particles carry the same charge. Based on the principle of
"like repels like", electrostatic repulsion is generated between pigment particles, thus moving away from each other
and avoiding agglomeration; second, the adsorption layer formed by the dispersant on the surface of the pigment
particles produces a steric hindrance effect, just like building a "protective wall" around the pigment particles to
prevent the particles from reaggregating and ensure that the pigment is evenly and stably dispersed in the
aqueous medium.
2. Multiple Roles in Water-Based Paints
(I) Create brilliant colors and enhance decorative effects
Water-based dispersants are the key to achieving excellent color performance of water-based paints. When dispersants
are not used or used improperly, pigments are very easy to agglomerate, resulting in color difference and flowery
problems after the paint is applied, which seriously affects the decorative effect. Water-based dispersants can effectively
break the agglomeration state of pigments and make titanium dioxide, color pigments, etc. evenly distributed in the paint.
Taking water-based paint for building exterior walls as an example, high-quality water-based dispersants can make the wall
colors more vivid and full, with natural color transitions and no obvious color difference, greatly improving the beauty of
the building's appearance. At the same time, evenly dispersed pigments can also give full play to their hiding power, and
only a small amount of paint is needed to achieve the ideal hiding effect, reducing the cost of use.
(II) Optimize construction performance and improve coating efficiency
A good dispersion state has a significant impact on the construction performance of water-based paint. Water-based
dispersants can reduce the viscosity of the paint system, making the paint have better fluidity and thixotropy. During the
construction process of roller coating, spraying, brushing, etc., the paint can be applied to the surface of the substrate
more smoothly, and it is not easy to have problems such as sagging, brush marks, and bubbles.
For example, in the spraying construction of large-scale building walls, the use of paints with high-performance water-based
dispersants can greatly improve the spraying efficiency, make the coating smooth, reduce the workload of rework and repair,
and effectively shorten the construction period. In addition, dispersants can also improve the storage stability of paints,
prevent pigments from settling and stratifying during storage, and ensure that the paint always maintains a good performance
state when used.
(III) Enhance coating performance and extend service life
Evenly dispersed pigments can better play a protective role in water-based paint coatings. In the field of water-based
anti-corrosion coatings, water-based dispersants promote the uniform dispersion of anti-rust pigments and their close attachment
to the metal surface, forming a dense protective film that effectively blocks the erosion of water, oxygen, and corrosive media,
significantly improving the anti-rust and corrosion resistance of the coating.
For water-based coatings used outdoors, such as water-based wood paints and water-based automotive paints, well-dispersed
pigments can enhance the weather resistance and wear resistance of the coating. Pigments evenly distributed in the coating can
more effectively absorb and scatter ultraviolet rays, reduce the damage of ultraviolet rays to the coating, and slow down the aging
and fading of the coating; at the same time, they enhance the wear resistance of the coating, making it less likely to be scratched or
worn in daily use, and extending the service life of the coating.
3. Important functions in water-based inks
(I) Achieving accurate color reproduction and ensuring printing quality
In water-based inks, the role of water-based dispersants is directly related to the color quality of printed products. The printing
industry has extremely high requirements for color accuracy, especially for high-end packaging printing, color album printing and
other fields. Water-based dispersants ensure that the pigments are evenly dispersed in the ink, so that the ink has stable coloring
power and transparency, and ensures that consistent color effects can be achieved on different printing batches and different printing
equipment, avoiding color difference problems caused by pigment agglomeration.
For example, in the water-based ink used to produce food packaging boxes, dispersants ensure the accurate reproduction of the ink
color, making the pattern on the packaging box bright and clear, highly consistent with the actual color of the product, and enhancing
the visual appeal and brand image of the product.
(II) Improving the printability of inks to meet the needs of high-speed printing
Water-based dispersants can significantly improve the rheological properties of water-based inks, giving them good fluidity and
transferability. During high-speed printing, well-dispersed ink can be quickly and evenly transferred from the printing plate to the
surface of the substrate, ensuring that the printed pattern is clear and the dots are complete, avoiding problems such as smearing,
flying ink, and tailing.
For flexographic printing, gravure printing and other processes commonly used in the packaging and printing industry,
water-based dispersants optimize the printing suitability of inks, allowing inks to better adapt to different printing plates and
substrate materials, such as paper, plastic film, metal foil, etc., ensuring the stability and consistency of printing quality and
meeting the high-speed and efficient production needs of the modern printing industry.
(III) Assisting green printing and promoting sustainable development of the industry
As an important component of the water-based ink system, water-based dispersants have strongly promoted the green
transformation of the printing industry. Compared with traditional solvent-based inks, water-based inks use water as the
main solvent, which greatly reduces the use of organic solvents, reduces the emission of volatile organic compounds (VOCs),
and effectively reduces pollution to the atmospheric environment.
The reasonable application of water-based dispersants ensures the stability of the performance of water-based inks, making
them comparable to solvent-based inks in terms of color and printing suitability, thereby accelerating the widespread
application of water-based inks in the printing industry. From environmentally friendly packaging printing to publication
printing, water-based inks have gradually occupied market share with their environmental advantages, and water-based
dispersants have provided solid technical support for this green process, helping the printing industry achieve sustainable
development.
Water-based dispersants play an irreplaceable role in the field of coatings and inks due to their unique mechanism of
action and significant efficacy. Whether it is to improve product performance or promote environmental protection
transformation of the industry, water-based dispersants have demonstrated their powerful strength. With the continuous
advancement of science and technology, the performance of water-based dispersants will continue to be optimized and
upgraded, bringing more innovation and development opportunities to the coatings and inks industry, and writing a
new chapter of green environmental protection.
