– Disperse Attagel® inorganic thixotropic thickeners with high shear
– Add at the grinding stage
– Attagel® pre-gel can be used for low shear systems
– Typical use level is 0.5% – 3.0%, including thick coating applications
– Excessive additions may affect the gloss of the coating
Coating is a multiphase mixed system. The specific surface area and the number of particles increase greatly after the pigment is crushed, so it is a thermodynamically unstable system. The stability of the pigment particles depends entirely on the steric hindrance formed by the adsorbed polymer and the electric double layer established by the adsorbed counter-charge. But this stability is only relative. what is the formula of amide?
The high molecular polymer adsorbed on the surface of the colloidal particles can effectively prevent the agglomeration of the colloidal particles and keep the dispersion in a stable state. This stabilization effect is called the steric cation effect.
The mechanism of steric hindrance stability Mack or first proposed the effect of steric hindrance stabilization. He believed that the stability of colloids is determined by entropy repulsion: AG=-TAS. In this case, the water is far repulsive and will not cause coagulation. But this is not the case, and flocculation will also occur.
Napper believes that for a dispersion system with stable steric hindrance, dispersion power is not the main reason for its instability. The cause of flocculation is the solvent’s solvency. When the solvent’s solvency drops below zero, the polymer in the dispersion medium will mutual attraction. This gravitational force is the cause of flocculation of the dispersed colloidal particles near 6 o’clock.
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