Water based epoxy resin coatings have excellent metal adhesion and corrosion resistance, as well as good chemical stability and bonding properties. Water based epoxy resin coatings are currently the focus of research in the coatings industry.
1. Classification of water-based epoxy resin paints
At present, there are many varieties of water-based coatings, which can be roughly divided into three main types: water-dispersible, colloidal-dispersed, and water-soluble. The two components widely used in the market are hydrophobic epoxy resin and hydrophilic amine curing agent, which can be divided into five types according to the physical form of the two components.
There are many classification methods for water based epoxy resins. According to the classic classification method, water based epoxy coating paint are divided into 4 types: type I, type II, type III, and type IV:
Type I water-based epoxy resin body is composed of low-molecular-weight liquid bisphenol A epoxy resin and water-based curing agent. Various reactive diluents are used to adjust the viscosity of the epoxy resin and the crosslinking density of the cured coating film.
Type Ⅱ uses high molecular weight solid bisphenol A epoxy resin. Epoxy resin is a lipophilic molecule, and its hydrophilic-lipophilic balance (HLB) is less than type III.
Type III is composed of low-molecular-weight liquid epoxy resin emulsion and water-based epoxy curing agent. Low-molecular-weight liquid epoxy resin emulsion is generally prepared by reverse conversion technology.
Type IV water-based epoxy resin is improved from Type III. It is composed of water-based epoxy resin emulsion and polyurethane modified epoxy curing agent.
2. Application of waterborne epoxy coating
Due to the excellent performance and characteristics of water-based epoxy resin, it is widely used in roof leakage prevention, airport runway, viaduct pavement reinforcement, parking lots, sports fields, factory floors, walls, ships, decks, basements and warehouses, aircraft carriers Aprons, tunnels and other fields.
The water-based epoxy coating can be applied on the surface of wet or freshly poured concrete, has good adhesion to the surface of the concrete, can seal the water vapor of the concrete capillary, and can prevent efflorescence. Water-based epoxy paint for concrete are suitable as concrete sealing primers.
