Nano coating preparation and application
Nano-coatings are generally made by mixing nano-materials and organic coatings. Therefore, more scientifically speaking, it should be called nano-composite coatings. It is generally believed that two conditions must be met before it can be called a nano-coating: the particle size of at least one phase in the coating is in the range of 1-100nm; the existence of the nano-phase makes the performance of the coating significantly improved or has new functions .
Nano coatings are composed of film-forming substances, pigments and fillers, additives, and solvents. Compared with ordinary coatings, nano coatings have the following characteristics: they can produce negative ions and have a health care effect on the human body; they can decompose and absorb harmful substances in the air, such as formaldehyde, etc.; have unique anti-mildew and sterilization functions; and have super self-cleaning Function; has super resistance to washing; super resistance to artificial aging; has the function of waterproof and super heat insulation.
Classification
- Nano silica coating
Silica architectural coatings do not delaminate, are thixotropic, anti-sagging, have good application performance, and greatly improve stain resistance, and have excellent self-cleaning performance and adhesion. The nano-silica coating can form a network structure when it is dried, which can improve the smoothness and anti-aging degree of the coating of vehicles and ships.
- Nano titanium dioxide coating
Nano-titanium dioxide architectural coatings can improve the weather resistance of latex paint to a new level. The application technology of the catalytic composite coating is simple and low in cost. The atmospheric environment purification coating made by the nano-titanium dioxide photocatalytic oxidation technology has a good purification effect on nitrogen oxides in the air and can also degrade other pollutants in the atmosphere.
- Nano calcium carbonate coating
Calcium carbonate is an excellent filler and white pigment with the characteristics of low price, abundant resources, good color and high grade. Application studies have shown that the flexibility, hardness, leveling and gloss of nano-calcium carbonate filled coatings are greatly improved.
Main equipment used in production
The application of nano-materials in coatings has greatly improved the performance and environmental protection of coatings, and has become the darling of the market. The main equipment for the production of nano-coatings has the following five types.
- High-speed dispersion machine
The high-speed disperser is used to pre-mix the paint and the grinding slurry.
It is mainly used to grind difficult-to-disperse pigments, fillers, and coatings into color pastes or grind to the specified fineness.
- Paint mixing equipment
After dispersion, the finely ground paint slurry and some coating resins, coating additives, solvents and color pastes are mixed uniformly with paint mixing equipment, and reach the specified color, viscosity and other indicators. Some coatings also need to use a high-speed disperser to adjust the paint.
- Filter equipment
Filtering equipment is used to filter a small amount of coarse slag and other impurities in the paint after the paint is finished, so as to achieve the purpose of purification. The commonly used equipment is a vibrating screen, which is easy to operate and easy to clean.
- Filling equipment
Filling equipment is divided into manual and automatic paint filling equipment, which is used to seal the finished paint packaging of specified volume and quality.
Application field
- Nano waterproof coating
Nano-waterproof technology mainly uses nano-scale molecular organic coating materials. In a vacuum and dust-free environment, the electronic products are perfectly packaged through ultrasonic vibration to achieve the same function in the water nano-waterproof coating as in the normal state of use.
- Self-cleaning nano coating
The self-cleaning nano-coating makes it easier to keep the solar panels clean and higher working efficiency, reducing maintenance and operating costs. Utilizing the dual phobic mechanism of nanomaterials, the water in the coating can be effectively discharged, and the intrusion of external water can be prevented, so that the coating film has the performance of breathing. At the same time, the physical properties of the dual interface of nanomaterials are used to effectively discharge the intrusion of dust and oil, so that it maintains good self-cleaning properties.
- Nano coatings for optical applications
The particle size of the nano-particles is much smaller than the 400-750nm wavelength of visible light, and has a transmission effect, thus ensuring the high transparency of the nano-composite coating. Nano particles have a strong absorption effect on ultraviolet light. Add TiO2, SiO2 and other nanoparticles to exterior wall architectural coatings to improve weather resistance, and add TiO2 to automotive topcoats to improve the aging resistance of automotive coatings.
- Stealth Nano Coating
Nano stealth material has excellent absorbing characteristics, and at the same time has the characteristics of good compatibility, small quality and thin thickness. The coating made of it can reduce the detection distance of the detector in a wide frequency band. Visible light, infrared and sound have a stealth effect, so they have a wide range of applications in the military.
- Nano antibacterial coating
The irradiation of light can cause the TiO2 surface to form a wonderful super amphiphilic property where the hydrophilic and lipophilic two phases coexist in the area where the negative ions are washed and returned to the ecological protection rice. Domestically, industrially produced nano antibacterial powders have been used in coatings, and nano antibacterial coatings can be made, which can be applied to building materials, such as sanitary ware, indoor spaces, appliances, walls and floors in hospital operating rooms and wards, etc. Sterilization and cleaning effect.
Reference
Li Xunsheng et al. “Application Examples of Composite Nanomaterials in Coatings”
Ke Changmei et al. “Preparation of Nanocomposite Coatings”
Wang Zhiqiang et al. “Nano Coating and Its Preparation”
Zhang Xiaojuan. “Overview of the Development of Nano Coatings”