Waterborne epoxy resin Generally, epoxy resins are categorized into hydrophilic and emulsifiable types. Hydrophilic epoxy resins are produced by grafting hydrophilic groups onto the original main chain of the epoxy resin, giving it partial water affinity and enabling self-emulsification. Note that while these resins are emulsified, they remain insoluble in water—allowing them to be separated via demulsification—and can subsequently crosslink with water-based curing agents.

　　As the name suggests, an emulsified waterborne epoxy resin emulsion is formulated without altering the structure of the system—using external emulsifiers, water, and employing vigorous dispersion to create a stable epoxy resin-in-water emulsion.

　　Hybrid methods, along with other approaches, can also be used for the hydration treatment of epoxy resins; however, they are rarely employed due to the significant changes in the structure and properties of the epoxy material.

　　The manufacturing process for hydrophilic epoxy resins isn’t complex. To avoid compromising the intrinsic properties of the epoxy resin, commonly used hydrophilic groups are hydrophilic amine compounds—such as monofunctional polyetheramines—that exhibit excellent crosslinking behavior with the epoxy resin but do not form fully closed-loop crosslinks.

　　The manufacturing process and equipment for hydrophilic epoxy resins are relatively simple and convenient, with reaction temperatures ranging from room temperature to moderate levels. These are designed based on the resin's melting point and reactivity.

　　Characteristics of hydrophilic epoxy resins:

　　1. The chemical properties of the raw materials remain largely unchanged, though some physical properties—such as DG temperature and surface hardness—may vary slightly. This is because ED is added simultaneously during the bonding process, leading to an increase in flexible groups. However, these changes can be adjusted and corrected using a curing agent.

　　2. During the application of self-emulsifying hydrophilic epoxy resins, water can be freely added to adjust the moisture content and viscosity without compromising the dilution effect or increasing the negative impact on drainage. These hydrophilic epoxy resins serve as an ideal water-free adhesive coating that cures and crosslinks effectively in damp or aqueous environments.

　　3. Self-emulsifying hydrophilic epoxy resin contains no emulsifiers, making it an excellent environmentally friendly product. Since it is free of emulsifiers, it avoids issues like separation of anionic and cationic compounds when replicating downstream products with other emulsifying agents, thus ensuring stable storage life and preventing accelerated demulsification.

　　4. Hydrophilic epoxy resin. Theoretically, all thermosetting epoxy resins can be technically modified, but in practice, low viscosity and low epoxy equivalent weight are more suitable, while high softening point and high epoxy equivalent weight are more challenging to incorporate and pose certain storage difficulties, making mixed dispersion operations impractical.

　　Characteristics of emulsified epoxy resin:

　　1. The emulsified epoxy resin is forcibly dispersed in water using a suitable emulsifier. As a result, a key feature of emulsified epoxy resins is that, after demulsification and curing, they largely retain their original properties—thanks to the wide variety of resin types available for selection.

　　2. Emulsified epoxy resins typically require vigorous dispersion with a specific amount of water directly at the factory; they generally achieve complete dispersion only when the solid content is around 50%. These products demand high storage stability and stringent transportation requirements, resulting in relatively higher costs.

　　3. Emulsified epoxy resins allow for the recovery of emulsifiers, provided that a properly sealed environment with no excessive contamination requirements is maintained and the recovery equipment remains in good condition. Additionally, environmentally friendly emulsifiers often result in more significant pollution during disposal, with some posing greater risks compared to solvent-based emulsifiers.