High performance acrylic resin leads the development of architectural coatings in China
building walls can be kept clean and tidy for a long time because the dust stuck to the walls can flow down with the rain because they are painted with magic paint; Due to a layer of protective paint covering the parts of cars and motorcycles, even if the hard material is in "close contact" with it, it will not leave a trace. The high-performance acrylic resin and application technology independently developed by Chinese scientific and technological personnel have made Chinese architectural coatings approach the international advanced level in an all-round way, and made domestic automotive coatings successfully enter the spare parts market, attracting international well-known companies such as German Henkel, American Behr, American GE, British Imperial Chemical and so on. This technology won the second prize of the 2009 National Technological Invention Award
according to Professor Wu Limin, director of the advanced coating engineering research center of the Ministry of education and director of the Department of materials science of Fudan University, the project leader, reducing VOC emissions while pursuing high performance has become a consensus in the global coating industry. China is the largest paint production and consumption country next to the United States, but the R & D and production of medium and high-end resins and coatings have been dominated by imitation for a long time, and we can only rely on imported resins and pigments and fillers to adjust the formula. Due to the inability to form its own core technology and the lack of research on the design and preparation of key raw materials such as resins, pigments and fillers, China has been at a disadvantage in the competition with foreign countries in the field of resins and related coatings for a long time, and the medium and high-end coating markets such as automotive and electronic industries are almost monopolized by foreign companies, The intellectual property of core technology is controlled by foreign scientific research institutions and companies. If the capacitor bypass input end is invalid and its output end is bypassed, the fault phenomenon disappears
Professor Wu Limin said that two methods can be used to achieve the goal of high performance and low VOC emission: one is water-based, that is, people often say water-based coatings; The second is to improve the solid content of oily coatings. Acrylate coating with acrylic resin as film-forming material has become the most widely used product in architectural coatings because of its excellent weather resistance, water resistance, acid and alkaline resistance, stain resistance, non-toxic, environment-friendly and other properties. At the same time, in the automotive industry, especially in the topcoat and midcoat of cars, the use of high solid content acrylate paint is considered by the University of Manchester to be increasing. It is also in vain to keep up with the later services. With the support of the national "863" plan and the relevant science and technology plans of Shanghai, they chose acrylic resin, which is the largest and most widely used coating resin, as a breakthrough. At present, they have applied for 11 Chinese invention patents and 2 international patents around this project, including 10 Chinese patents and 1 U.S. patent, and published 53 international SCI papersaccording to Professor Wu Limin, when the solid content continues to increase, the viscosity of the system will increase, and the subsequent deployment and construction work will become more and more difficult. In order to increase the solid content and reduce the content of organic solvents in the system, the molecular weight and distribution of the resin must be effectively controlled. In order to solve this contradiction, they invented the separation and polymerization technology of high solid acrylic resin, which not only improves the solid content of the resin solution, but also ensures that the system has a low viscosity
after that, researchers obtained high solid and low viscosity nanocomposite acrylic resin by surface modification of nano silica sol. Because it solves the problem of difficult dispersion and agglomeration of inorganic nanoparticles in nano coatings, the solid content of acrylic resin prepared by them is more than 90%, and the coating performance partially exceeds that of foreign high solid solvent based coatings. This technology has been industrialized in Guangzhou, and its products have been applied in many famous automobile, motorcycle and household appliance manufacturers, partially replacing imports
Wu Limin believes that water-based coatings use water as a solvent, and there is no doubt about their environmental protection. But generally speaking, there is still a certain gap between the comprehensive performance of water-based coatings and oil-based coatings. In order to overcome the above disadvantages, they invented a new technology for the preparation of soap free acrylic resin lotion without any traditional emulsifier: using the characteristics of weak negative electricity or weak acid and hydrophilicity of the silicon hydroxyl group on the surface of nano silicon dioxide, through electrostatic or acid-base interaction, nano silicon dioxide particles are adsorbed to the surface of single body fluid drops and generated acrylic emulsion particles during the polymerization of monomers, playing the function of emulsifier, It solves the problem that traditional acrylic resin lotion synthesis requires a large number of organic small molecule emulsifiers
in addition, they further developed and invented the preparation technology of high solid and low viscosity nano composite polyester and coating, as well as the preparation technology of silylated polymer post lotion with nano silica particles as emulsifier
at present, this technology has been industrialized in Jiangsu and Shanghai. The pollution resistance of the produced water emulsion acrylic resin coating is less than 5% (the national standard is 15%, the smaller the value is, the better), the self-cleaning is good, and the artificial accelerated aging time is up to 1600 hours. This innovative achievement can be seen in national major projects such as CCTV building and studio, WorldExpo and its relocation projects, because it solves the problems of easy sticking and discoloration of exterior wall paint decoration in construction projects
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