Preparation And Properties Of Aqueous Acrylic Ester Resin And The Water-borne Coating

Due to water as the solvent, the drying speed of water-based varnish is slow, andit is easy to form bubble and shrinkage cavity. And due to the larger evaporation heatof water, the films require a higher curing temperature, and the water resistance of thecuring film is also unsatisfactory. In order to seek methods to improve waterresistance of the curing films, we do a research on the synthesis of aqueousdispersion-type acrylic resin and the properties of curing films which use amino resinand aziridine as the curing agent.The research on the preparation of aqueous dispersion-type acrylic resin and itscuring films show that: with the increase in the content of MAA and HEMA, thewater-solubility of the resin decrease, and the viscosity increases; with the increase inthe content of AAEM, the water-solubility of the resin increase, and the viscositydecreases; with the increase in the content of dimethylethanolamine, thewater-solubility of the resin first increase and then down, and the viscosity decreases;When the content of MAA, HEMA, AAEM and dimethylethanolamine are7wt%,10wt%,10wt%and5.8wt%, the soft and hard monomer ratio is35/45, the content ofCY303is40phr and curing condition is160°C×30min, the resin has good watersolubility and the curing films have good properties. The TG analysis shows that, withthe increase in the content of HEMA, the thermal stability of the curing films firstincreases and then decreases, and reaches the best when the content of HEMA is10wt%; FT-IR analysis of resin, curing agent and curing film show that, AAEM andHEMA have involved in the crosslinking reaction; SEM analysis of curing films’surface morphology show that, using isopropanol as solvent to dissolve curing agentand curing catalyst which can help curing agent and curing catalyst disperse in resin,and the curing films have excellent mechanical properties and water resistance.The research on aqueous dispersion-type acrylic resin which use MAA andAAEM as functional monomers, and its aziridine curing films show that, with theincrease in the content of MAA, the water-solubility of the resin decrease, and theviscosity increases; with the increase in the content of AAEM, the water-solubility ofthe resin increase, and the viscosity decreases; with the increase in the content oftriethylamine, the water-solubility of the resin first increase and then down, and theviscosity decreases; When the content of MAA, AAEM and triethylamine are10wt%,10wt%and5.87wt%, the soft and hard monomer ratio is35/45, Using Sac-100as the curing agent and curing condition is130℃×30min, the curing films have goodproperties.The research on aqueous dispersion-type acrylic resin which use MAA andHEMA as functional monomers, and its aziridine curing films show that, with theincrease in the content of MAA, the water-solubility of the resin decrease, and theviscosity increases; with the increase in the content of HEMA, the water-solubility ofthe resin decrease, and the viscosity increases; with the increase in the content oftriethylamine, the water-solubility of the resin first increase and then down, and theviscosity decreases; When the content of MAA, HEMA and triethylamine are10wt%,7wt%and7.1wt%, the soft and hard monomer ratio is35/48, Using Sac-100as thecuring agent and curing condition is140℃×30min, the curing films have goodproperties.The research on aqueous dispersion-type acrylic resin which use MAA, AAEMand HEMA as functional monomers, and its aziridine curing films show that, Whenthe content of MAA, AAEM, HEMA and triethylamine are10wt%,3wt%,7wt%and7.1wt%, curing condition is130℃×30min, the curing films have good properties.GPC analysis show that, with the increase in the content of functional monomer, themolecular weight and its distribution of three kinds of resin introduced before do notchange significantly; DSC and TG analysis show that the curing films havereasonable Tg and good thermal stability; FT-IR analysis show that, the functionalmonomers in three kinds of resin all have involved in the crosslinking reaction; SEManalysis show that, curing films are smooth, and the surfaces of the films do notappear shrinkage cavities and protrusions.The aqueous dispersion-type acrylic resin which can be used to have crosslinkingreaction with amino resin and aziridine, its curing films not only have high gloss andexcellent mechanical properties, and also have excellent water resistance, which solvethe problem that water-borne curing films have poor water resistance. The properties,especially the water resistance of the curing films have reached the requirements ofthe automotive varnish, they are excellent water-based varnishes, which haveindustrial development value.