The Preparation And Application Of Water-Borne Driers For Alkyd Paint

Water-borne alkyd resin from renewable plant resources has been studied widely in recent year, because it is regarded as a material that meets the requirements of sustainable development of environment. For waterborne alkyd resin, directly transferred from solvent-borne alkyd is a common way. However, the metal driers, the most crucial additive for alkyd, are really not easy to be directly transferred from solvent-borne driers to water-borne driers with the same method. Firstly, the metal ion in conventional solvent-borne metal driers will form a hydrated metal ion complexes such as [Co(H2O)6]3+in the water-borne alkyd because of the presence of water, which lead to the loss of catalytic activity of metal ion during drying. Secondly, the neutralizer in water-borne alkyd which is various organic and inorganic amines will also react with the metal ion in conventional solvent-borne metal driers to reduce the catalytic activity of driers. All above problems will finally lead to the drying loss of water-borne alkyd film. Therefore, it is really important and urgent to develop a water-borne drier with good drying activity and hydrolysis resistance.In this work, a series of alkyl acetoacetate and alkyl acetoacetate metal complexes was synthesized. Through the experiment of oxygen absorbing changes of solvent-based alkyd film which contained cobalt complex, the effect of acceleration on oxidative cross-linking process was observed, and the anticipative effect of dry was achieved. Furthermore, the same results were also obtained in the water-borne alkyd resin which contained unsaturated plant oil. The researches of the compatibility, drying speed and hydrolysis resistance of different metal complex driers in different water-borne alkyd resin and water-borne alkyd paint were also conducted systematically. By comparison, the difference of the water-borne complex and emulsified water-based complex was studied as well. From the research results, the metal complex driers have not only solved the problems, such as drying loss, hydrolysis existing in the conventional solvent-borne driers and water-borne driers in the market, but also improved the compatibility and storage stability of water-borne driers in the water-borne alkyd systems. Moreover, infrared and nuclear magnetic resonance were used to monitor the variation of functional groups in the alkyd during oxidative drying. The weight change of the alkyd film was observed during evaporation process. The drying mechanism of metal complex driers in the water-borne alkyd film was concluded in accordance with above-mentioned experiments. The results show that the complex-type driers are very suitable for water-borne alkyd film and interactions among the drier and other compositions in the water-borne alkyd resin. To develop water-borne driers for the environment-friendly alkyd resin is very important for the coming future, and there are still lots of challenge and unknown ahead for us to explore.