The Synthesis And Application Of High-performance Acrylic Emulsion

Recently, there appears serious environmental problem as air haze in some areas, which has caught people’s attention on environmental pollution again. The volatile organic compounds (refferred as VOC) in traditional paint is considered as a major source of air pollution as the same as the the smoke particulates and vehicle emissions. Compare with the traditional solvent-based coatings, the waterborne coating can greatly reduce the VOC emissions. And acrylic emulsion resin plays an important role in the waterborne coatings. Generally speaking as the thermoplastic film, polyacrylate emulsion film extensively exists some problem like cold crisp and hot sticky. Therefore cross-linking is regarded as one of universal modification in the acrylic emulsion. Among that, the one-component room temperature crosslinking technology is the preferable modification because of its simplicity, low energy consumption and low cost. In this paper, the ambient crosslinking acrylic emulssion is successfully synthesized using acetoacetyl, then modify the acrylate emulsion with the fluorinated acrylate monomer, finally we obtained a fluorine-modified ambient crosslinking acrylic ester copolymer emulsion and prepared a water-based imitation metal plastic paint. The main research can be divided into three parts:1.Through the emulsification semi-continuous emulsion polymerization process, using acrylate monomers as raw material, the ambient crosslinking acrylic emulsion is finally prepared, furthermore, the ratio and amount of emulsifier, the initiator dosage, the ratio of hard and soft monomer, the amount of crosslinking monomers are discussed. The emulsion is characterized by the laser particle size analyzer, fourier transform infrared spectroscopy (FTIR) and other analytical instruments. The results showed that when the ratio of anionic to nonionic emulsifier is 2:1, emulsifier amount is 0.3%, and initiator amount is 0.5%, the sample get the best effect of emulsion. The as-resultant latex exhibits pan-blue light, and the conversion of monomer is 95.5% and the gel rate is 0.3%, with the average particle of 80.2nm. Besides, the as-prepared emulsion film exhibit an excellent performance at room temperature when the ratio of m (hard monomer) to:m (soft monomer) is 1.8:1 and the content of AAEM monomer is 7%. More specifically, the film showed the best comprehensive performance, that the hardness reach 3H and impact resistance could be 50 Kg.cm impact, besides water resistance of the coating film reached 72 h, and the coating’s Acid-resistant (5% H2SO4) was 12 h and the alkali resistance (5% NaOH) was 24 h.2. The acrylate emulsion is modified with the flourinated acrylate monomer, discussing the effect of the type and amount of fluorine-containing monomer on the emulsion and film properties. The results shows that when the amount of fluoromonomer B is 20%, the fluorine-modified acrylate copolymer emulsion get the excellent performance as the monomer conversion is 95.2%, with latex particle size of 82.6nm and the narrow pariticle size distribution. Furthermore, the film exhibits the execllent comprehensive performance, as the hardness of 3H and impact resistance of 50 Kg.cm impact. Besides the acid resistance and alkali resistance has significantly improved, as the coating’s Acid-resistant (5% H2SO4) and the alkali resistance (5% NaOH) are 7d.3.With the use of flourine-modified ambient crossliking acrylate copolymer emulsion, metallic effect pigments and chemical additives, the aqueous imitation metal plastic paint is successfully prepared, and the selection and amount of resin emulsion type, effect pigments, chemical additives for film properties are discussed. The results indicate that, when using the homemade acrylic emulsion as film-forming matrix, the dosage of effect pigment and water-based wax emulsion is 8%,1.5%, respectively, then the adhesive force of film reach 0 degree and the rigidity reach 3H. The film’s metallic index reachs 13.5, and exhibits excellent metallic imitation effect, moreover the paint can be stored at room temperature for 30 d without any settlement.