Study of the styrene–acrylic emulsion modified by hydroxyl-phosphate ester and its stoving varnish

A styrene–acrylic copolymer emulsion containing hydroxyl-phosphate as flash-rust functional monomer and hydroxypropyl acrylate as cross-linking monomer was synthesized. The effects of the hydroxyl phosphate dosage, the hydroxypropyl acrylate dosage as well as the ratio of soft to hard monomer on the emulsion and coating film were investigated. The results showed that the emulsion of 4% hydroxyl phosphate function monomer and 3% hydroxypropyl acrylate with soft and hard monomer ratio of 1:1.6 and modified emulsion and amino resin ratio of 6:1 resulted in a coating film with the best performance.

► In this study, we synthesized a functional monomer.
► Monomers of cross-linking were introduced in polymerization.
► Different ratio of hybrid monomers was observed.
► Optimal protection function is related to the suitable dosage monomers.