| Amino baking paint is a kind of coating that combines decorative and anti-corrosion performance.It is mainly used as top coat for automotive and other high-grade metal surfaces.There are high requirements for surface roughness,mechanical properties and weather resistance of paint films.However,for the current waterborne acrylic amino baking paints,there is some performance need to be improved,such as adhesion,water resistance and weather resistance,and surface smoothness of the paint film.In this project,a self-made waterborne phosphate modified fluoroacrylic emulsion was prepared and used as a matrix resin to prepare a waterborne amino baking coating.Through introduction of phosphate ester monomer and fluoromonomer,the adhesive of the paint film to the metal substrate,as well as water resistance,thermal stability,weatherability,and gloss of the film were improved.The study contents in this dissertation mainly include the synthesis of new acrylic emulsion,the preparation of aqueous emulsion acrylic amino anti-corrosion coating and the preparation of waterborne acrylic amino baking paint.(1)A novel phosphate-modified fluorine-containing hydroxy acrylate was prepared using hexafluorobutyl acrylate(G-01)and phosphate ester monomer(PP-70)as functional monomers.The influence of the type and amount of initiator on the properties of the emulsion was investigated.It was found that when reactive emulsifier SE-10N and non-ionic emulsifier TX-30 were used as the emulsifier system,the ratio of the two emulsifiers was 2:1,and the dosage of the two emulsifiers was 2%of the total monomers,the properties of the emulsion are the best.(2)Self-made water-based acrylate emulsions were used as the main film-forming components,Cymel-325 as a curing agent,titanium dioxide as a pigment,combining with the use of some water-based coating additives,a new type of water-based acrylic amino anti-corrosion coating was prepared.The effects of cross-linking monomer and functional monomer on the varnish and the titanium white paint were studied,respectively.Finally,an optimal formula was obtained as follows:hydroxypropyl methacrylate(HPMA)was used as cross-linking monomer and the dosage was 10%,the dosage of hexafluorobutyl acrylate(G-01)was 5%,the dosage of phosphate ester monomer(PP-70)was 2%.(3)Effects of many factors such as curing agent,leveling agent,baking temperature and baking time,and pigment ratio of titanium white paint on the performance of the waterborne acrylic amino baking paint were investigated.An optimal formula was obtained,that is,Cymel-325 amino resin was used as the curing agent,the curing temperature is 140?,a curing time is 30 minutes,and the ratio of acrylic resin to amino resin is 5:1.When the titanium white paint base ratio is 0.4,the titanium white paint film has the best performance.When using the BYK-375 as the leveling agent and the dosage is 1%of the total amount of the formula,the paint film gloss can reach 90 degrees.In addition,the effect of four different strong acid catalysts on the curing reaction was studied.It is found that using the strong acid as a catalyst can lower the baking temperature of the film by about 20?.Finally,a comparative experiment was conducted based on self-made acrylate amino anticorrosive paint with two commercially available products.It was found that,based on the present formula,the performance of the aqueous emulsion acrylate anti-corrosion coating prepared in this dissertation are much better than that of commercially available two emulsions paints. |
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