ZINC-RICH PAINT is the most important electrochemical antirust pigment. A primer made with a large amount of zinc powder is called a zinc-rich primer. Zinc-rich paint is divided into an inorganic zinc-rich primer with silicate as binder and epoxy zinc-rich primer with epoxy resin as a binder. Compared with other metals, zinc has its unique characteristics. It is lighter than iron and has good ductility. It can be alloyed with iron. The most important thing is its electrochemical activity. Its standard electrode potential is -0.76V, which is livelier than Iron (-0.44V). Zinc can be melted and purified into fine particles of high-purity zinc powder, which is used as the most important anti-rust pigment in anti-rust paint.
When the coating film is corroded, the zinc powder is corroded as the anode first, and the substrate steel is the cathode, which is protected. The oxidation product formed by the zinc as the sacrificial anode has a sealing effect on the coating and can still strengthen the coating protection to the substrate. In zinc-rich coatings, zinc powder is gradually consumed during the protection process, but the speed is very slow. The formation of its corrosion products reduces the potential difference between the coating and the substrate. When the paint film is damaged, new metallic zinc is exposed, and the potential difference increases immediately, resulting in strong cathodic protection. Therefore, the rust of the zinc-rich primer will not spread from the damage to the surroundings.
Advantage of Epoxy Zinc-rich paint
- Good cathodic protection
- Good anti-corrosive property, quick drying, good adhesion power, excellent impact and abrasion
- Available for gas cutting and welding.
- Excellent adhesion to the sandblasted steel
Specification of Epoxy Zinc-rich paint
| Type | Solvent | ||||
| Solid Content | 71.5% | ||||
| Mixing Ratio | two components base : hardener=10:1 by weight | ||||
| Dry Film Thickness | 20μm per coat | ||||
| Specific Gravity | 1.6kgs/Liter | ||||
| Coverage Rate (Theoretical) | 0.07kg/m2/20μm 0.044L/m2/20μm | ||||
| Drying Time | Temperature | 10℃ | 20℃ | 30℃ | |
| Dry to touch | 6mins | 8mins | 5mins | ||
| Dry Hard | 18hrs | 5hrs | 3hrs | ||
| Package | 30kgs for one kit, part A 27kgs, part B 3kgs | ||||