Study On Polymerzation And Modification Of Acrylate Core-shell Emulsion And Performance Of Coating

Recently, exterior emulsion coating has been more and more used in the decoration of walls. It has been also a sort of dominantly decorative material depending on its variety of colors, convenience of painting, easiness of maintenance, lightness of deadweight, non-pollution of environment. Although having been extensive applied, exterior emulsion coating also is facing with huge challenges, especially its stain resistance. So it is imperative to enhance the stain resistance of coating under the situation.In this paper, two technical methods are introduced to enhance the stain resistance. One is, on the basis of"the latex particle design", controlling the structure and form of latex particles to do research on the influence of properties of coating by the core-shell emulsion. To adjust the Tg of the emulsion and improve its film quality and the stain resistance, soft monomers and hard monomers are mixed in the polymerization of core and shell of latex particles. Comparing soft-core/hard-shell, hard-core/soft-shell and common latex with latex sold in the market, it proves that soft-core/hard-shell latex is the best in view of the stain resistance, and makes certain the ratios of core to shell and soft monomers to hard monomers in the polymerization. The other is adopting chemical methods to improve the stain resistance of coating by mixing cross-linking monomers, silicon, fluorid monomers in the shell-polymerization of soft-core/hard-shell latex. The mixed monomers in the shell include HEMA, MAA, HFMA, WD-21, KH570, D4. Moreover, fluorid emulsifier, used with common emulsifiers, will take effect in the polymerization.After a great deal of experiments, conclusions have reached: the stain resistance of coating is enhanced effectively after mixing HEMA, its dosage is 1.5 percent of shell-polymerization monomers; HFMA, WD-21 also have partly improved the stain resistance, their dosages are separately 6 percent and 2 percent of monomers; When fluorid emulsifier, compounded with common emulsifiers, is 10 percent of gross of emulsifiers, it has an effect on polishing up the stain resistance.