The Modification of the Acrylate Emulsion for Water-Based Coatings

第44卷第5期复旦学报(自然科学版)Vol. 44 No.52005年10月Jourmnal of Fudan University (Natural Science)Oct.2005Article ID: 0427-7104(2005)05-0899-02The Modification of the Acrylate Emulsionfor Water-Based CoatingsChen Wei-Feng, Fa-Ai Zhang(Key Laboratory of Nonferrous Materials and New Processing Technology, Ministry of Education ;Department of Material and Chemical Engineering, Gruilin Uniersity of Technology, Guilin 541004, China)Keywords: water based; modification; silicone; acrylate emulsionCLC number:O 634Document code:A1 IntroductionThe developments of the environment friendly materials and technology are largely promoted recently.There also come some new kinds of coatings including water based coating, powder coating, high- solid coatingand UV-cured coating 1] . The emulsion polymerization is the main method for preparing the polymer for c∞at-ings. One of the most widely used polymers is acrylate resin which is not well in some properties, such asweather resistance, endurance and water resistance2]. We hope to improve the various properties of theacrylic emulsion by adding silicone made from tetraethyl orthosiliate(TEOS), making it better applied incoating field.2 ExperimentalThe silicone -modified acrylic emulsion was synthesized by core/shell emulsion polymerization methodwith the raw materials, including methacrylic (MAA), methyl methacrylate (MMA), butyl acrylate (BA)and tetraethyl orthosilicate. The detailed steps are as follows:Firstly, the silicone was prepared by adding the water, alohol, hydrochloric acid and TEOS into theflask which is fitted up with stirrer, decompression and distillation, and removing the byproduct at 40 to 50C.Secondly , the deionized water mixed with some emulsifiers in another flask in high speed until the emul-sifiers were fully resolved. Then some monomers and initiators were added into the mixture to react to formthe seed emulsion I。Thirdly, the left monomers and the silicone made in the first step were added into the deionized water re-solving some emulsifiers to form emulsion IFourthly, the emulsion I and solution of the left initiators were slowly added dropwise into the flaskwithin 3 to 4 hours to react with the emulsion I to produce the finished product.3 Discussion中国煤化工The acrylic emulsion was modified by adding silicone madfprove the propertiesof the emulsion and performances of the film. The film made f:CHCNMHGon are of enduranceReceived date: 2005 -08-05Biography: CHEN Wei feng ,Correspondence author ,e mail: chenweifeng- 2005@163. com.900复旦学报(自然科学版)第44卷when exposed on the ultraviolet and oxygen, and the introduced silicone can cause mild cross links betweencopolymer chains, thus improving the mechanical properties of the film. The various properties are showed asTab.1.Tab.1 The effect of the level of the silicone on propertiesLevel of silicone/Glossy degreePencilStabilityDrying time/hWater resistanceAdhesion Visosity/sHardness0good6106.8Light whiteH11.25good .90.5No change13.22894.23H13.3711delamination92.213. 58The Tab. 1 shows that the emulsions are stable when the levels of silicone are lower and will be delami-nated if the content of silicone reaches 11%. The drying timne are reduced with the content of silicone increas-ing, improving the application performance. The property of water resistance had best at the 5% and 8%contents of silicone, and the hardness is 3H at 8% while dropping at other contents. The adhesion is notchanged with the content of the silicone changed. The viscosity is increased obviously when 5% content of sili-cone is added, and changed lttle with the content increasing.The stable emulsion was prepared by core/shell emulsion polymerization method and the properties of theemulsion and the performances of the film were improved obviously, such as drying time, water resistance,hardness and viscosity through modification by adding silicone made from TEOS into the emulsion, but theglossy degree is reduced.References:1] Zeno W , Frank N,Peter S. Science and technology of organic paints. Version by Jing Fu-liang. Beiing: ChemicalIndustry Press,2002.[2] You Bo. The reearch of the proerties of the slicone mdified acrylate emulsion and coating[J]. Technology ofCoatings , 2000(1) :21-24.中国煤化工MYHCNMHG