Analysis of the problem of water-based anti-corrosion paint flash rust

The flash rust of water-resistant anti-corrosion paint has been a problem that has been bothering people for a long time. The production of flash rust is an electrochemical process in which
causes are related to the dissolution and precipitation of metal compounds. Because the water-based coating itself is a conductor, the charge migration channel is formed for different areas where the cause difference is present, and corrosion is produced under the joint action of water
oxygen
.
Different metal substrates, water-based paint construction process flash rust phenomenon is produced quickly or to varying degrees, the general situation of flash rust is: cast iron aluminum carbon steel galvanized plate (grinding) > makou iron (grinding) > iron plate (or wire aluminum alloy).
factors and analysis of flash rust:
1
, metal substrate, water, oxygen. The existence of these three points at the same time is the root cause of flash rust, but it is also an unavoidable factor. Metal substrate should choose not easy to rust, and try not to be contaminated;
2
, paint selected body resin performance. Resin is the main body of the coating, its ion structure and conductivity and other properties will directly affect the paint's rust.
3
pH value of
,
paint.
pH
value on flash rust is also more obvious, the higher the
pH
value, the lower the risk of flash rust, it is recommended
pH>9.5
, and it is important to choose a more stable
pH
regulator.
4
, coating drying speed. Flash rust is generally produced in the drying process, speed up the drying speed, can effectively reduce the risk and degree of flash rust generated by this process.
5
, paint film thickness, temperature and humidity, ambient wind conditions, etc. can affect the drying speed of the coating to affect the rust.
6
, anti-flash rust additives. The rational use of anti-flash rust additives can effectively prevent the production of flash rust.
7
, rust-proof pigments. Such as zinc phosphate, aluminum phosphate, etc.