Ultrafine pigment powder is mainly divided into organic pigments and inorganic pigments, organic pigments are mainly divided into azo pigments, lake pigments, heterocyclic pigments, thick ring ketone pigments, phthalocyanine pigments and other pigments. Inorganic pigments are mainly divided into titanium dioxide, carbon black, iron oxide red, etc. Organic or inorganic pigments have bright colors, high coloring strength, high color power and high transparency, which meet the requirements of coatings and printing inks.
However, in the process of preparing pigment powder, the finer the particle size, the surface of pigment powder will increase, which can easily lead to agglomeration, making large particles, paint and ink system instability, seriously affecting product quality.
At this time, organic ammonium salt dispersant is needed to add to the pigment crushing process, pigment dispersant in the pigment paste system, mainly adsorb to the surface of the powder, reduce the surface energy of ultrafine pigment particles, to achieve uniform dispersion effect, and organic ammonium salt dispersant can effectively prevent flocculation back to coarse settlement floating color hair. Good compatibility with paint and printing ink to improve color rendering performance.
Why does Dispersing agent NNO work?
The Dispersing agent NNO molecule contains an anchor group and a stabilizing part. The role of the anchoring group is to provide a strong enough binding force to the pigment filler particles. Dispersant molecules do not fall off the surface of particles, which is a prerequisite for dispersant to work. The function of the stabilizing part is to stabilize the pigment aggregate particles dispersed by mechanical force through electrostatic repulsion and spatial resistance in the liquid phase to prevent the particles from aggregating.
In organic solvents, when the stable part of the dispersant stabilizes the dispersed pigment particles by spatial resistance, when the spacing of the Dispersing agent NNO particles is smaller than the size of the solvent chain, the solvent chain squeezes each other and the entropy decreases. In water, ionization occurs around ionic groups to form a double layer, and electrostatic repulsion prevents particle agglomeration. If non-ionized polyether is stable, polyether stabilizes dispersed pigment particles by spatial resistance.
Post time: May-19-2022