Research On Two-component Colyurethane Coatings Of Environmentally Friendly

Emission of organic compounds causes great harm to public health and ecological environment.Emission of organic solvent is about 5 million tons annually,more than half of which is from painting industry.In China,Solvent based paint and coating accounts for 55.3%market share of paint and coating,being almost twice than 28.5%in the global market.Two component polyurethane coatings is one of solvent based paint coatings,being excellent at adhesion,chemical resistance,abrasion resistance and decorative performance,widely used in many fields.But benzene solvents have great harm to human health and cause serious pollution to the environment,while it is widely used in organic solvent because of its excellent solubility and low price.Their usability is limited,So coating of environment friendly with non-benzene has become a new direction of coating development.The following work is done on the research of environmentally friendly two-component polyurethane coatings in this paper.(1)Solvent with benzene used in two-component polyurethane coatings is replaced by environmentally friendly mixed solvents Regarding to the principle of selection of mixed solvents and the properties of the coating,the mixed solvent DBE,ethyl acetate,butyl acetate solvent have been chosen.After continuous optimization of the proportion,the ratio of the three had been determined as 5.0?10.0:45.0?47.5:45.0?47.5.(2)Experiments were carried out on the curing agent and resin agent ratio;pigment volume ratio,the amount of drying agent,and the amount of additives.The performance of the environment friendly two-component polyurethane coating was better than those of benzene solvent wile the content of three benzene is less than 0.5%.(3)At last,a gas chromatography method for benzene model of two-component polyurethane coating has been established,using fixed phase of two methyl polysiloxane HP-1 weak polar capillary column,setting the inlet temperature is 140 centigrade.And the experimental results showed that this method is stable,with high precision and better linearity.