To understand aluminum and silver paste, we must start with his industry
classification. Aluminum-silver paste belongs to chemical
industry->fine chemicals->inorganic pigments->metal pigments,
and metal pigments are divided into two categories, namely copper
pigments and aluminum pigments. Copper pigment is what we usually call
copper gold powder/gold paste, and another aluminum pigment is our
protagonist this time-aluminum silver paste. Before introducing aluminum
silver paste, we must first have a basic understanding, that is, what
is the difference between pigments and dyes? Dyes are colored organic
compounds, which are generally soluble in water or organic matter, or
some insoluble dyes are changed into a dispersed state by chemical means
to promote dissolution. The pigment is different. It is an insoluble
colored compound, generally insoluble in water, oil and solvent, but can
be uniformly dispersed in the solvent. Generally speaking, the pigment
exists in the solvent in the state of particles, and the dye exists in
the solvent in the state of molecules. In the huge family of pigments,
there is one of the most "shining and dazzling" members-aluminum silver
paste. It is called aluminum-silver paste because it is mainly composed
of aluminum flakes and petroleum solvent, which is in the form of a
paste. After processing through a special treatment process, the surface
is smooth and flat, showing a silver metallic luster, so people call it
aluminum silver paste.
At the same time, it also has many aliases, such as silver paste, silver
powder paste, aluminum powder paste, flash paste, etc. According to the
arrangement and distribution of aluminum in the aluminum-silver paste,
it is mainly divided into floating aluminum-silver paste and
non-floating aluminum-silver paste: floating aluminum-silver paste
refers to the distribution of aluminum pigments on the entire coating,
and the arrangement is relatively neat and capable It exhibits excellent
metal effect, achieves the effect of imitation electroplating, high
brightness, and strong corrosion resistance, but its adhesion is
relatively weak and it is not easy to color. Non-floating
aluminum-silver paste means that the aluminum pigments are distributed
in the middle and lower parts of the coating, and the arrangement is
messy. It will show the metallic effect of "different colors at
different angles", with strong adhesion and easy coloring. But
relatively speaking, the metallic feel is weaker than floating silver.
According to the construction process of aluminum silver paste, it is
mainly divided into fine silver, imitation electroplating, and flash
silver. Fine silver: In the construction process, the aluminum sheet is
crushed by a steel ball, and then ball milled until the diameter of the
aluminum sheet is broken (aluminum is originally a piece of piece), and
then smoothed to open its ductility to make it Higher hiding power.
Generally, fine silver is characterized by its poor metallic feel and
high hiding power. The particle size is generally below 12μ. Imitation
electroplating: Through the grinding of the ball mill little by little,
on the premise of ensuring that the diameter of its sheet is not broken,
and the structure of the aluminum itself is not damaged, the diameter
of the sheet is opened to grind the metal feeling. Generally, the
characteristic of imitation plating is that it has a strong sense of
metal, but the production is relatively time-consuming. The particle
size is generally below 12μ. Flash silver: The process is much simpler
than the imitation electroplating and fine silver process, and the
effect it presents is flashing. The particle size is generally divided
into fine flash, medium flash and coarse flash, and the particle size is
between 15μ and 64μ. After we roughly understand a basic concept of
aluminum silver paste, we need to further understand its related
properties. Which mainly involves metallic feeling, hiding power,
adhesion, stability, dispersion and other characteristics of different
industries. Metallic: the appearance of aluminum silver paste; Covering
power: the arrangement of the aluminum sheet is tight, whether it can
cover the substrate with the least amount of addition; Adhesion: Whether
the silver paste can be well wrapped in the resin system without losing
silver; Stability: Whether there is no reaction in the aluminum-silver
paste coating system to ensure a long service life; Dispersibility:
Whether the aluminum silver paste can dilute well without sedimentation
and agglomeration. Of course, the above are just some common attributes.
For each industry, there are different test indicators. For example,
the glass paint must be resistant to alcohol, and the printing must be
resistant to washing.