Research and Prospect of Waterborne Epoxy Anti-corrosive Epoxy Paint?

Corrosion is a major cause of energy loss and material waste. Corrosion causes 1/5 of the world's energy and 4.2% of GNP loss every year, and the economic loss caused by corrosion in the United States is more than 100 billion US dollars each year. The usual way to avoid material corrosion is to use a protective layer or paint.

Because epoxy resin contains epoxy groups and other special structures, it has strong adhesion and good corrosion resistance, so it has excellent anti-corrosion performance in coatings, so it is widely used in the preparation of water-based anti-corrosive epoxy paints.

Ⅰ. Base material of water-based anti-corrosive epoxy paint

It is mainly composed of two components of hydrophobic epoxy resin and hydrophilic amine curing agent. Among them, the emulsification of epoxy resin, the ratio of epoxy resin and curing agent and their compatibility directly affect the anti-corrosion performance of coatings. In the preparation of the new epoxy anticorrosive paint, the characteristics of the binder and the pigment and filler are mainly considered so that it can be effectively applied to the paint.

Ⅱ. Anti-corrosion mechanism and research status of base material in water-based anti-corrosive epoxy paint

The base material is the main film-forming substance in the coating, and the protective mechanism for the metal mainly includes the following points.

1. Physical shielding of corrosive media

Through the cross-linking between the epoxy resin and the curing agent, a three-dimensional network structure is formed, which improves the density of the coating, reduces the voids of the coating, and prevents or inhibits the penetration of oxygen, water, and electrolyte ions through the coating film, forming a kind of mechanical shield.

This shielding effect isolates the substrate from the corrosive medium and blocks the passage of the corrosion cell, thereby reducing the diffusion of the corrosive medium to the interface between the coating and the substrate, preventing the formation of the corrosion cell and inhibiting the progress of the corrosion activity.

2. Resistance effect of paint film

Most of the film-forming substances of the coating are polymer organic compounds, which have good insulation and high resistance, which can hinder the movement of ions between the anode or cathode and the solution, and play the role of intervening high resistance in the solution of the corrosion battery.

3. Adhesion

The coating of the epoxy component has strong adhesion to the metal, which enhances the effectiveness of the shielding effect of the coating, thereby slowing down the rate of corrosion reaching the substrate, thereby enhancing the anti-corrosion ability.

In recent years, the hydrophilic emulsifiers and cross-linking agents remaining in the coating during the curing process of water-based anti-corrosive epoxy paint affect the chemical resistance of the coating. For the research of water-based anti-corrosive epoxy paint, many scholars focus on the use of Various methods are used to modify the base material, optimize the formula and improve the preparation process conditions. The modified resin emulsion or curing agent can significantly improve the adhesion and anti-corrosion properties of the coating.