Preparation And Properties Of The Transparent And Heat-insulating ITO Film Cured At Room Temperature

Indium tin oxide (ITO) has excellent features such as high transparence of visible light, high infrared-insulating properties, high electrical conductivity, and so on. Currently it is known as the transparent and heat-insulating material that has the best properties. ITO as the function heat-insulating material coated on the glass surface can effectively solve the heat-insulating problem of transparent glass. Therefore, studying and optimization the prepared process of the ITO film have great practical significance.Firstly, ITO nano-powders were prepared by chemical co-precipitation method. The results revealed that to be obtained ITO, the precursor should go through high temperature calcinations heat treatment more than350℃. The powders calcinated at600℃have cubic bixbyite crystal structure, good crystallization and the grain size is about20nm. The microscopic morphology of the ITO powders is spherical particles, and the electric conductivity is36.6S/cm.Secondly, the preparation processes of ITO aqueous slurry and coating were researched. The results showed that, the optimum pH of the ITO aqueous slurry is3to4, the optimum ITO powders content is6%, the optimum dispersant is DT-03and its content is10%of ITO powders. The ITO aqueous slurry dispersed1h of high-speed disperser at a speed of4000r/min, then ultrasonic dispersing15min, have the best dispersion stability. Prepared the bicomponent ITO aqueous polyurethane coating, hydroxy aqueous polyurethane as film-forming agent, the volume ratio of ITO aqueous slurry and aqueous polyurethane is1:2, and the aqueous cross linker having NCO group as curing agent. At room temperature, the bicomponent ITO aqueous polyurethane coating can be cured naturally to get ITO film in24hours.Finally, the transparent and heat-insulating ITO films are prepared by painting the bicomponent ITO aqueous polyurethane coating on the glass substrate through dipping-pulling method. The effects of the pulling speed and frequency on the visible-light transmittance, infrared-insulating and heat-insulating properties of ITO films are researched. The results revealed that, the pencil hardness and adhesion of ITO films are3H and0respectively, they reached the national standard. With the increase of the pulling speed and frequency, the thickness of the ITO film is increased, the visible light transmittance of the ITO films decreased gradually, and the infrared-insulating and heat-insulating performance increased. But the degree of influence of the pulling speed is greater than pulling frequency. The ITO film whose pulling speed is10mm/min has the best heat-insulating property, the temperature difference is more than4℃compared with Blank glass substrate.