Coating technology: application of nanotechnology in architectural coatings

It is pointed out that the coating is the underwear (interior wall coating) and outer wall coating of buildings The traditional coating in China has the defects of poor suspension stability, aging resistance, washing resistance and poor finish Nano composite coating is to use nano powder for coating The obtained coatings have the properties of aging resistance, radiation resistance, high peel strength or some special functions Its application in building materials (especially architectural coatings) has shown its unique charm The same nano particle will have different effects under different particle sizes, and different kinds of nano particles can also play the same role in the coating Application scope and advantages of roller ceramic coating Recommended introduction: the surface of ceramic rubber plate used for roller ceramic coating is cast into durable rubber plate by hundreds of independent small ceramic pieces Each ceramic piece has raised characteristics Under general conveyor belt pressure, thousands of unique cast bumps can produce positive traction, prevent slipping and extend the service life of conveyor belt roller At the same time, the bottom layer adopts high-quality rubber, which has strong elasticity and can play a good impact resistance role The scope of application of roller ceramic coating is one three six 83857180 (the same as V) 1 Roller coating in extremely harsh working environment 2 The belt joint is not suitable for fixing with iron buckle; 3 It is suitable for leather Paint Home News: paint is the underwear (interior wall paint) and coat (exterior wall paint) of buildings The traditional paint in China generally has the defects of poor suspension stability, aging resistance, washing resistance and poor finish Nano composite coating is to use nano powder for coating The obtained coatings have the properties of aging resistance, radiation resistance, high peel strength or some special functions Its application in building materials (especially architectural coatings) has shown its unique charm The same nano particle will have different effects under different particle sizes, and different kinds of nano particles can also play the same role in the coating According to the applications of nanocomposite coatings, it can be summarized as follows: 1 The particle size of nanocomposite coatings for optical applications is far smaller than the wavelength of visible light of 400-750nm, which has the function of transmission, thus ensuring the high transparency of nanocomposite coatings Nano particles have strong absorption effect on UV TiO2, SiO2 and other nano particles are added to the exterior wall building coating to improve the weather resistance, and TiO2 is added to the automobile finish to improve the aging resistance of the automobile coating Nano-SiO2 is an amorphous white powder (refers to its aggregate) There are unsaturated residual bonds and hydroxyl groups in different bonding states on its surface Its molecular state is three-dimensional chain structure Generally speaking, the hydrogen bond on the surface of nanoparticles will recover rapidly after the elimination of external shear force, making its structure recombine rapidly This kind of shear weakening reaction, which depends on time and external force, is called thixotropy Thixotropy is the main factor to improve the performance of traditional coatings Xu Guocai et al Doped nano silica into UV curable coating by nano particle filling method The results show that nano silica can reduce the absorption of UV radiation and the curing speed of UV curable coatings, but can significantly improve the hardness and adhesion of UV curable coatings In particular, rutile type ultra-fine TiO2 can also play the role of effect pigment in automobile top coat When it is used together with other sheet effect pigments such as aluminum powder pigment or pearlescent pigment, it will produce angular heterochromism accompanied with milk light, which can be used in luxury car top coat This is the largest use of nano TiO2 at present, and also one of the most successful examples of application of nano materials in coatings abroad Due to the small size, large specific surface area, different bond states on the surface and the internal of particles, and incomplete coordination of surface atoms, the active sites on the surface increase and the reaction contact surface increases Therefore, nano zinc oxide is also a good photocatalyst Under UV irradiation, it can decompose organic substances, play the role of antibacterial and deodorization Photocatalyst with this property can be used in environmental protection coatings, and nano ZnO can significantly improve the anti-aging ability of coatings 2 Due to the very small size of nano ultrafine powder, the absorbing nano composite coating has the ability of absorbing electromagnetic wave They have a strong absorption effect on radar wave and infrared ray of different wavelengths Therefore, the coating modified by nanoparticles can be used in military stealth coating The U.S once reported a kind of "super" blackbody nano absorbing material, that is, ultra-fine graphite nano absorbing coating, which can absorb 99% of the radar wave The military camouflage coating has been successfully prepared with nano carbonyl iron powder, nickel powder and ferrite powder in foreign countries, which has been applied to aircraft, warships, missiles, submarines and other weapons and equipment, making them have the camouflage performance Nano coating materials have the advantages of wide absorption band, light weight and thin thickness, which are expected to play an important role in military stealth in the future 3 The irradiation of nano self-cleaning antibacterial coating can lead to the formation of hydrophilic and lipophilic super amphiphilic on the surface of TiO2 For example, the nano antibacterial powder which has been industrialized in China can be used in coatings to produce nano bactericidal coatings, which can be applied to building materials products, such as sanitary ware, indoor space, appliances, walls and floors of hospital operating rooms and wards, and play a role in sterilization and cleaning Under the light with wavelength less than 400nm, nano-TiO2 particles can absorb the short wave light radiation which is higher than the band gap width, generate the electron transition, make the valence band electrons excited to the conduction band, and form the electron hole pair, transfer the energy to the surrounding medium, induce the photochemical reaction, thus have the photocatalysis performance Nano ZnO is also an efficient bactericide Under ultraviolet irradiation, nano ZnO can decompose negative electrons (E -) in water and air (oxygen), and leave positive holes (H +), which can activate oxygen in the air to become active oxygen, have strong chemical activity, and can oxidize with a variety of organic matters (including organic matters in bacteria), so as to Most germs and viruses kill Northwest University has carried out quantitative germicidal test of nano zinc oxide When the concentration of nano zinc oxide is 1% in 5 minutes, the killing rate of Staphylococcus aureus and Escherichia coli is 98.86% and 99.93%, respectively Therefore, adding nano zinc oxide to cosmetics can not only shield ultraviolet rays from sun, but also can resist bacteria and deodorize 4 Panasonic company of Japan has successfully developed nano composite coating with good electrostatic shielding effect, and the nano particles used include Fe2O3, TiO2, ZnO, etc These nano oxide particles with semiconductor characteristics have higher conductivity than conventional oxide particles at room temperature At the same time, the color of nano oxide particles is different This kind of coating not only has electrostatic shielding characteristics, but also overcomes the monotony of coating color 5 Nano high mechanical property coating when the pigment particles, an important part of the coating, reach the nanometer size and disperse in the coating, because of its large specific interface and great binding force, it can enhance the organic coating to a certain extent, and improve the hardness, impact resistance and wear resistance of the coating In addition, the nano particles can reduce the residual stress of the coating during the drying process, so as to enhance the adhesion of the coating The results show that nano-SiO2 particles in UV curable coatings can significantly improve the hardness and adhesion of the coating, and the wear resistance and scratch resistance of furniture surface paint and automobile finish paint modified by nano materials are also greatly improved Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,