Comparison of the advantages and disadvantages of several commonly used crosslinking agents for water-based resins

Comparison of the advantages and disadvantages of several commonly used crosslinking agents for water-based resins:

The common hydrophilic groups in water-based resins include carboxyl, hydroxyl, amino, and aldehyde groups. Among them, the carboxyl group can cross link with a variety of functional groups to obtain a three-dimensional network structure. Moreover, the presence of carboxyl monomer can also improve the adhesion of the coating film to the metal substrate, and make it easier to control the viscosity of lotion. Therefore, it is a functional group commonly used in the development of diplomatic lotion.

1. Aziridine crosslinking agents have fast reaction rates and significant effects, and are currently one of the more mature and effective room temperature crosslinking agents under research. Therefore, it can only be used as a two-component crosslinking agent.

2. Polycarbodiimide (PCDI) crosslinking agents have the advantages of low toxicity and high efficiency, which can improve the water resistance of coatings while maintaining their original characteristics. Its reaction rate with carboxyl groups is slow, and the crosslinking effect can only reach its optimal level after 4-5 days.

3. Polyisocyanate crosslinking agent: Polyisocyanate crosslinked coatings have high glossiness, mechanical strength, and solvent resistance. When mixed with water-based resins, the crosslinking effect of this crosslinking agent is very short, ranging from 2-10 hours, and trace moisture in the coating and air may affect the crosslinking effect.

4. The characteristics of metal ion crosslinking agents for metal ion crosslinked polymer materials are high crosslinking density, good transparency, and good solvent and water resistance.

5. Epoxy resin cross-linking agent The film made of lotion with epoxy resin as cross-linking curing agent has good adhesion, mechanical strength, pollution resistance and solvent resistance. The crosslinking mechanism of this type of crosslinking agent is similar to that of aziridine crosslinking agents, but with slightly lower reaction activity, slower crosslinking rate, and slightly higher temperature requirements. The crosslinking reaction at room temperature generally takes 3-5 days to complete.