A New Emulsion Paint Remover

In traditional paint remover, chlorinated hydrocarbon and high toxic and volatile organic solvent are usually applied, resulting in environmental pollution. In order to protect the environment, a new emulsion paint remover with low toxicity and volatility was prepared by single factor test and orthogonal test in this work.For the paint remover, 1-methyl-2-pyrrolidone and benzoic acid methyl ester were applied as the main solvent,1,4-butyrolactone and benzyl alcohol were applied as the co-solvent, acetic acid was applied as the activator and cetyl trimethyl ammonium bromide was applied as the emulsifier, which were added into the de-ionized water. The results showed that when the mass ratio of 1-methyl-2-pyrrolidone and benzoic acid methyl ester was 1:1 and the mass ratio of 1,4-butyrolactone and benzyl alcohol was 2:1, the paint remover showed good performance for four typical organic coatings:epoxy zinc-rich, acrylic modified alkyd, fluorocarbon and acrylic polyurethane. The paint remover was a clear and milk-while liquid with the proportion of 1.05 g/cm~3 and the flash point of 82 ℃.Based on the optimum formula, the effects of each component and its content on the performance of the paint remover were studied with the method of single factor test. The results showed that the paint remover showed good performance when the content of main solvent, co-solvent, activator and emulsifier were about 35-55%,10-25%,6-12%and 1-3%, respectively.It was found that temperature, stirring rate and coating thickness could affect the efficiency of paint remover. In the temperature range from 0 ℃ to 75 ℃, both the efficiency of paint remover and the evaporation rate of solvent increased with the increase of temperature; however, at ambient room, the paint remove also showed relatively higher efficiency. Under the studied stirring rate of 0,300 and 1200 r/min, there was no significant effect of stirring rate on the efficiency of paint remover. In the thickness range from 30±5μm to 130±5μm, the efficiency of paint remover decreased with the increased thickness of four typical organic coatings; however, the paint remover could take off four coatings with the thickness of 130±5μm in a short time.It was found that the addition of methyl cellulose in the paint remover could improve the application and stability of paint remover, and the stability increased with the increased content of methyl cellulose. When the content of methyl cellulose was 3%, the paint remover showed relatively better performance.The volatility, cycle use and corrosion of paint remover also were studied. The results showed that the quality retention percentage of paint remover was more than 99% in half hour at each temperature of 0,25 and 45 ℃, indicating the relatively lower evaporation rate. The paint remover showed good application of cycle and could be used repeatedly. Corrosion tests showed that the corrosion rate of carbon steel, copper alloy and aluminum alloy were low after immersing in the paint remover.