Large pore capacity silica matting agent is a controlled particle size, high purity, porous, synthetic amorphous silica particles, is a non-toxic, tasteless, non-combustible white powder.
The product has better transparency and dispersion effect compared to other silica matting powder, significantly larger porosity, narrower particle size distribution, greatly improving the matting efficiency of the product, organic wax surface treatment products, can be added directly to any process in the production of coatings, can also be added after the paint to adjust the gloss especially used in full matte paint paints, with excellent suspension, smoothness and excellent dispersion properties.
It is difficult to classify pigments and binders absolutely into lipophilic or hydrophilic. Here, inorganic pigments are regarded as hydrophilic, and organic pigments are regarded as lipophilic. This division ignores the nature of the pigment surface. As far as inorganic pigments are concerned, the degree of hydrophilicity is also different, and some are similar to lipophilic. Organic pigments are also approximately hydrophilic.
2. Wetting effect
When the liquid contacts the solid surface, the original solid/gas interface disappears and a new solid/liquid interface is formed. This phenomenon is called wetting. Only when the bonding force between the pigment and the resin solution is greater than the bonding force between the resin in the base material, carnauba wax additive the wetting effect will occur.
1. Wetting and contact angle
When liquid and solid come into contact, an angle is formed. This angle is called the contact angle, as shown in Figure 2-2. It is a measure of the degree of wetting of a liquid to a solid.
Wetting contact angle
The relationship between the contact angle and the southern tension can be expressed by Young’s equation:
YsG=YsL ten yi gcos f(2-1) where Ysc-solid/gas interfacial tension;
YSL-—-solid/liquid interfacial tension;
7LG-liquid/gas interfacial tension;
0——The contact angle between liquid and solid.
From formula (2-1), we can get:
When YsG<YsL, then co sd<0, 0>90″, no wetting will occur. When 0 is equal to 180°, there will be no wetting at all, and water drop rolling will occur.
When YuG≥YSG-7SL, then 1>co sf≥0, 0<90°, the liquid will wet the solid, but it cannot be completely wetted, and will not spread.
When Y LG=YsG-7sc, then co sf=1, 0-0° liquid will completely wet the solid.
Leave a message
We’ll get back to you soon