O-cresol epoxy resin (eocn) is a linear phenolic heat-resistant multifunctional epoxy resin prepared by the reaction of o-cresol resin (OCN) and epichlorohydrin (ECH). O-cresol epoxy resin is widely used as plastic packaging material for electronic components such as semiconductor equipment and integrated circuits to protect electronic components from environmental corrosion and maintain product performance and service life. Therefore, it is required that the resin has good performance and high purity, that is, the content of residual chlorine, sodium ion and hydrolyzable chlorine should be low. With the rapid development of electronic industry, the demand for (ECH) resin is increasing day by day, and the product purity is required to be higher. The lower the hydrolyzable chlorine content, the better.