The
addition of nano-silica to the coating improves the scrub resistance, strength,
hardness, and the like of the coating. Adding a small amount of nano-silica to
the coating, the performance of the coating can be improved from 250h to over
600h, the scrub resistance is increased by more than 10 times, the drying time
is greatly reduced, and the suspension stability of the raw material is poor
and thixotropic. Problems such as poor quality and low finish are also well
resolved. The canning effect of the coating added with nano-silica is also
obviously improved, the coating is not delaminated, anti-sagging, good
workability, greatly improved stain resistance, and has excellent self-cleaning
property and adhesion.
Technical
indicators:
Exterior
|
White powder
|
model
|
DK-SiO2-T30
|
The average particle size
|
30±10
nm
|
Specific surface area
|
150-300 m2/g
|
content
|
≥99.5%
|
PH value
|
4-7
|
Burning weightlessness 950℃x2h
|
≤6.0%
|
Application
characteristics of nano-silica in coatings:
1.
washable: washability improved from thousands to tens of thousands of times
2.
weather resistance: weather resistance can be increased by about 3 times,
adding a certain amount of nano-silica can improve the UV aging resistance of traditional
coating products from the original 250h to more than 600h.
3.
Stain resistance and self-cleaning: Studies have shown that the stain
resistance and self-cleaning properties of the coating film can be improved by
the following methods: First, the microporous structure of nano-silica is used,
and the coating film is applied by a certain process. The surface forms a
geometrically complementary (such as convex and concave phase) interface
structure in the nanometer scale, so that it adsorbs air to form a stable gas
barrier film on the surface; the second is to surface treatment of the nano
silica particles, so that The surface is amphiphilic or double-sparing, which
effectively improves the wettability of the rainwater on the surface of the
architectural coating film and the adhesion of the dust, and improves the stain
resistance and self-cleaning ability of the coating film.
4.
Antibacterial property: In the coating, when the addition amount of nano silica
exceeds 0.5%, the coating exhibits an obvious antibacterial effect.
5.
hydrophobic anti-corrosion: Nano-silica hydrophobic anti-corrosion coating, not
only has good adhesion, corrosion resistance, but also has high density and
resistance to ion permeability.
6.
Transparency: Nano-silica can ensure the transparency of nano-modified
coatings. The use of nano-silica can produce a highly wear-resistant
transparent coating, which improves the wear resistance by more than 10 times.
7.
Hardness: When the nano-silica particles are uniform in the organic material
and the individual particles are dispersed, the nanoparticles enhance the
organic material like a rigid chain, thereby improving the hardness of the
coating film of the UV-curable coating, up to 2.5. More than double.
8.
Thermal stability: In the UV-curable coating, nano-silica can increase the
glass transition temperature of the coating film.
9.
Viscosity: The addition of nano-silica can significantly increase the viscosity
of the coating.
Add
amount:
It
has been proved by practice that 2% nano-silica is added to the coating to
achieve the best hardness, adhesion, weather resistance, viscosity and
anti-settling ability of the coating and stability of the coating. The
recommended dosage is 0.5-2%, and the individual product system can reach more
than 10%, depending on the actual situation.
Instructions:
The
dispersion of nano-silica can be carried out using various methods such as
milling, high-speed shearing, ball milling, sanding, ultrasonic dispersion, and
the like, with the first two methods being used more. Nano-silica is added to
the coating, and the dispersion step is divided into a one-step method and a
two-step method.
The
one-step method refers to adding nano-silica into the raw material system of
the product to directly obtain the required content of the product. The
one-step method is characterized by simple production process, and is suitable
for large-volume production of a single product.
The two-step method is to first disperse the nano silica into a raw
material to form a masterbatch, and then add the raw material to a certain
ratio. The two-step method is characterized by high viscosity of the system,
large shear force during dispersion, and good dispersion of nano-silica, which
is suitable for multi-species production. |