Passivation process: a key step to create stable aluminum silver paste

Passivation process is an important part of the aqueous treatment of aluminum silver paste, the process is as follows:

1. Put in solvent-based aluminum silver paste, use amphoteric solvents (such as alcohol ether, alcohol) for dilution and mixing, this step can quickly improve the agglomeration of aluminum silver paste, so that it is more evenly dispersed.
2. in the continuous mixing process, slowly add pre-diluted acidic polymers (such as epoxy phosphate, polyester phosphate, etc.), these polymers can be chemically reacted with the surface of the aluminum paste, the formation of a passivation layer, effectively preventing the aluminum paste and the aqueous system of components in the adverse reaction.
3. Maintain the stirring reaction for a certain period of time to ensure that the passivation layer evenly and densely covered on the surface of aluminum silver paste, to fully realize its stabilization effect.
4. After the completion of the reaction, let the mixture naturally precipitate, pour out the surface clear liquid, this step can not only reduce the original aluminum silver paste in the non-water solvent content, but also effectively remove the passivation process of black slag and other impurities, and further improve product quality.
5. Finally add wetting agent and mix well, the addition of wetting agent can adjust the hydrophilic and lipophilic balance of aluminum silver paste, so that it can be better dispersed when added to the water-based coatings, to avoid problems caused by the bias of oleophilic mixing does not open, to ensure that the uniformity and stability of the coating system.