| With the increasingly perfect environmental regulations and people's awareness of environmental, health, safety and energy saving increasingly grow, environment-friendly coatings were taken seriously increasingly. The research and development of water-borne resins and water-borne coatings is getting more and more deeply and widely, becoming one of the trend of the development of the coating industry.China started the research of waterborne alkyd resin from the early 60s. For many years, due to technical factors, it has developed slowly so far. At present, the R & D of water-based alkyd system in the domestic have a greater gap with similar foreign products. There are still many problems, such as poor storage stability, chemical resistance and water resistance, which directly affect the water-based alkyd resin widespread application and all-round development.This thesis focuses on the status of water-based alkyd paint, through the synthesis of water-borne alkyd resin and the modification study by epoxy, a kind of good storage stability, good water resistance and drying fast modified waterborne alkyd resin were prepared. Then part of the performance of alkyd resin was optimized on this basis, and then together with pigments and fillers, additives, etc. Ultimately, the water-based alkyd varnish and primer whose various aspects performance are largely improved.Alkyd resin was synthesized by Alcohol solution method. The factors that affect the performance of the resin were studied, such as types of raw materials, proportion of each material, temperature and acid value. IR was applied to characterize the structure of the product.The best synthetic conditions and formula of the water-borne alkyd resin were obtained. Soybean oil, tung, trimethylolpropane, isophthalic acid and trimellitic anhydride were used as the main raw materials to synthesize the water-borne alkyd resin.The properties of the water-borne varnish prepared by the water-borne resin were as follow:table dry was 3h,hard work was 24h, water resistance was 24h, storage for 4 months, pencil hardness was B.Because of its performance was ordinary, its application value was low. Water-based epoxy modified alkyd resin was synthesized through alcoholysising vegetable oil by Polyols. which modified by epoxy resin,followed by esterification condensation, carboxylation and neutralized by salt. The factors that affect the performance of the resin were studied, such as the types of epoxy resin, the proportion of epoxy resin, the order of epoxy resin, the temperature of the experiment and the dryer. The mechanism of the film of the curing and hydrolytic stability of the resin were discussed. IR was used to characterize the structure of the product. The optimal synthetic conditions and formula of water-borne alkyd resin were obtained. Soybean oil, tung, trimethylolpropane, epoxy resin,isophthalic acid and trimellitic anhydride were used as the main raw material to synthesize the water-borne alkyd resin. The suitable oil length of the resin was 48～50%, the alcohol excess was 1.2, the glycerol ester content was greater than 40% and the final acid value was 42～48 mgKOH/g. The properties of the water-borne primer prepared by the water-borne resin were as follow:table dry was 2h, hard work was 16h, water resistance was 32h no change, storage for 6 months without precipitation, pencil hardness was HB.To further strengthen the water resistance, drying, hardness and other properties of alkyd resin, Isocyanates, silica emulsion were used to modified alkyd resin again in the experimental process.The properties of the water-borne primer that prepared with the water-borne resin as follow:table dry was 1.5h,hard work was 14h, water resistance was 36h no change, storage for 8 months without precipitation, pencil hardness was H.Through comparison of the before and after modifying, modified water-borne alkyd resin with excellent dry performance, water resistance and storage stability. |
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