【目的】解决水性环氧乳液 VOC含量偏高、乳化剂添加量高以及在高颜料体积浓度（PVC）下涂膜防腐性能不佳等问题。【方法】利用二聚酸改性，采用特定工艺合成了高效乳化剂并用其制备了环氧乳液。通过红外光谱仪、激光粒度仪和差示扫描量热仪等表征了乳液和涂膜的性能。【结果】制备的环氧乳液稳定性好，高 PVC（46%）下的涂膜耐腐蚀性优异，耐盐雾性达到 400 h，板面无起泡，单边扩蚀不超过 2 mm。通过调整乳化剂亲水亲油平衡值（HLB）和相对分子质量，优化了乳液的粒径和细度。二聚酸的添加量为 14%时，乳液的综合性能最佳。【结论】与市售水性环氧涂料对比，经二聚酸改性的环氧乳液在柔韧性、硬度、耐冲击性等方面表现更为优异，且在相同 PVC条件下，防腐性能显著优于市售产品。

［Objective］In order to solve the problems of waterborne epoxy emulsion，such as high VOC content，high amount of emulsifier and poor corrosion resistance of coating film under highpigment volume concentration（PVC）.［Methods］A high-efficiency emulsifier was synthesized by a specific process using dimer acid as modifier，which was then applied to prepare epoxy emulsions. Theproperties of emulsion and coating film were characterized by FT-IR spectrometer，laser particle size analyzer and differential scanning calorimetry.［Results］The prepared epoxy emulsion exhibited excellent stability. The coating under high PVC（46%）has excellent corrosion resistance，and the salt spray test exceeded 400 h with no blistering on the panel surface，and the unilateral corrosion expansionwas less than 2 mm. The emulsion particle size and fineness were optimized by adjusting the hydrophilic-lipophilic balance（HLB）and molecular weight of the emulsifier. The emulsion exhibited the best overallperformance when the dimer acid content was 14%.［Conclusion］ Compared with commerciallyavailable waterborne epoxy coatings，the dimeric acid modified epoxy emulsion coatings showed superior performance in terms of flexibility，hardness，impact resistance. Moreover，under the same PVC conditions，the corrosion resistance was significantly better than that of commercial available products.