Application of the hottest nano ATO powder in poly

Application of nano ATO powder in polymer antistatic packaging materials

Abstract: This paper summarizes the research progress of the application of nano ATO conductive powder in polymer antistatic materials from three aspects: antistatic coatings, antistatic fibers and antistatic plastics, and points out several problems that need to be further studied

key words: nano ATO antistatic application

products need packaging, and the quality of packaging materials directly or indirectly affects the quality of products. In the past, most of the product packaging focused on its appearance, moisture-proof, heat insulation, thermal insulation and other properties, but did not pay enough attention to the anti-static and anti RF properties, which also caused serious consequences. It is reported that the losses caused by electrostatic discharge (EDS) in the electronic industry around the world reach tens of billions of dollars every year. In recent years, with the development of material science, polymer materials are widely used in packaging and other fields because of their superior performance in production, processing and use. The research on antistatic of polymer materials has also become one of the hot spots at home and abroad to create more value for users

the commonly used antistatic method of polymer materials is to add conductive fillers to the materials, but the existing conductive fillers have exposed many problems in the use process: precious metal fillers (such as gold powder, silver powder, nickel powder, etc.) have good conductivity, but the price is expensive, which is not suitable for large-scale use; Copper powder is cheap, but it is easy to be oxidized; The use of carbon filler is limited by its good conductivity and durability. Therefore, in the 1990s, foreign countries developed cheap and light colored metal oxide conductive fillers, which have developed rapidly. Nano antimony doped tin oxide (ATO) is an n-type semiconductor material. Compared with traditional antistatic materials, nano ATO conductive powder has obvious advantages, mainly in good conductivity, light color transparency, good weather resistance and stability, and low infrared emissivity. It is a new multifunctional conductive material with great development potential. This paper introduces the application of nano ATO powder in polymer antistatic materials from three aspects: antistatic coating, antistatic fiber and antistatic plastic

1 antistatic coating

antistatic coating is the main application market of nano ATO powder. Nano ATO powder is added to polyamide, acrylic acid and other matrix resins as conductive filler, and the nano composite transparent anti Qu Jinping electrostatic coating can be prepared by selecting an appropriate dispersion method. In the nano ATO composite antistatic coating, when the amount of nano ATO powder reaches a certain critical value, the conductivity of the coating is significantly improved. Research shows that the critical volume concentration (CPVC) of nano ATO powder in the coating is about 23%. When PVC reaches 23%, the conductivity of the coating is good, as shown in Figure 1. However, further increasing the amount of nano ATO will not help greatly to improve the conductivity of the coating. On the contrary, it will affect the color, transparency and mechanical properties of the coating. In addition, the type of matrix resin, the amount of solvent and the preparation process have a significant impact on the performance of the coating

due to the large specific surface area and high specific surface energy of nano ATO particles, they belong to a thermally unstable system. The powder particles spontaneously converge with each other to reduce the enthalpy of the whole system. The formation of agglomerated secondary particles, or even tertiary particles, will destroy the superfine and uniformity of the powder, affect the performance of the nano powder, and then affect the final use performance of the product 1). Therefore, the primary factor affecting the antistatic performance of coatings is the high dispersion of nano ATO powder

in view of how to realize the high dispersion of nano ATO powder in transparent conductive coatings, Li Qingshan et al d2] studied the formation conditions of the highly dispersed system of nano ATO powder prepared by coprecipitation in water through experiments, and discussed the influence of ball milling time and pH value on the dispersion system. The results showed that without any additives, the ball milling time needed more than 5 days to form a nano ATO powder water dispersion system with good dispersion effect; Nano ATO powder will agglomerate in the aqueous solution near the strong alkali and isoelectric point (ph=1.8), but in the aqueous solution far away from the isoelectric point (pH = 5), it can show different dispersion States, and can form a highly stable antimony doped tin oxide ultrafine powder aqueous dispersion system without agglomeration. Wang Dong et al. Studied the stability and dispersion behavior of nano ATO in water, discussed the effects of dispersant type, ATO dosage, pH value and dispersant dosage on the stability, dispersion and rheology of the system, and prepared nano ATO suspension with low viscosity and good stability dispersion

nano ATO composite antistatic coating is a functional material with a wide range of applications, such as transparent packaging film antistatic coating of electronic equipment, plane display material, surface heat generator, etc; In addition, nano ATO powder with different blue tones can be obtained by adjusting the doping amount of antimony, so as to obtain antistatic coatings with different colors, which is very important for its application in the field of packaging

2 antistatic fiber

nano inorganic powder modified fiber material is gradually becoming an important development direction of fiber material modification. Compared with other types of antistatic fibers, nano metal oxide antistatic fibers have many unique excellent properties, such as good stability without the limitation of climate and use environment; Nano scale metal oxide is not easy to fall off from the fiber, and the distribution is relatively uniform; The fiber preparation process is simple; Fiber has a wide range of applications, and can be used in almost any occasion requiring anti-static. New nano transparent conductive powder is favored by people because of its transparency and excellent conductivity. There are three main ways to apply nano ATO to the antistatic treatment of chemical fibers:

1) directly add nano ATO powder during fiber spinning. The key is the compatibility between inorganic nano ATO and fiber materials, and special dispersion additives need to be added

2) add nano ATO or its aqueous suspension in the dyeing process of raw materials (such as wool tops and polyester fibers) to complete the dyeing and functionalization in one step

3) add nano ATO aqueous suspension in the dyeing or finishing process of grey cloth

Wang Dong and others in the State Key Laboratory of fiber modification of Donghua University used nano powder ATO powder as antistatic agent and polyethyleneimine (PEL) as dispersant to stably and evenly disperse nano ATO in deionized water, and used the suspension as a preheating bath in the spinning process of polyacrylonitrile fiber for the first time to improve the antistatic property of PAN fiber. Due to the concentration difference of nano inorganic particles inside and outside the fiber and the existence of a large number of micropores inside the primary PAN fiber, nano ATO particles can enter the fiber or be adsorbed on the surface of the fiber through diffusion and migration. When the PAN fiber is stretched, dried and densified, nano ATO can remain in the fiber and form a conductive channel for local contact of nano ATO, giving the PAN fiber antistatic. The experimental results show that the volume specific resistivity of nano ATO modified PAN fiber decreases by three orders of magnitude, and has good antistatic properties, while basically maintaining the original mechanical properties of the fiber. In addition, the national superfine powder engineering research center is also carrying out research on the application of nano ATO in the preparation of anti static fibers and many other fields

at present, the main method to improve the electrostatic property of polyester fabric is to use organic antistatic agent to carry out antistatic finishing through simple fabric finishing technology. However, organic antistatic agents have many problems, such as high dependence on environmental humidity and poor durability of antistatic effect. Therefore, seeking an antistatic agent with excellent and durable antistatic performance has become a research and development hotspot. Wu Yue et al. EMI applied nano ATO powder to the antistatic treatment of polyester fabric. The experimental results showed that the surface resistance of polyester fabric treated with nano ATO antistatic finishing agent was reduced from the untreated 1012 to 1010. After washing for 50 times, the antistatic effect was basically unchanged. Chen Xuehua and others finished polyester fabric with anti-static function of nano ATO antistatic agent by coating method. The experimental results show that only when ATO particles are exposed to the surface of the film, it can play its anti-static performance; When ATO particles exist in the coating in the form of partial annihilation in the film and partial exposure on the film surface, the antistatic performance of the film will last. Ding Zhongfu and others used nano ATO powder with different antimony doping amount for antistatic treatment of polyester knitted fabrics. The research shows that the powder should check whether the power supply is normal. The doping amount is one of the main factors affecting the antistatic performance. Within the test range of 4% to 8% antimony doping amount, the more the doping amount, the better its antistatic performance, but the color of the powder also deepens, It will affect its use in light color textile products with good process layout and excellent stability

fiber functionalization is an important development trend of synthetic fibers. China is a large country in the production and consumption of chemical fiber, and the antistatic treatment of chemical fiber will be one of the important application markets of nano ATO powder

3 antistatic plastics

at present, antistatic polymer materials formed by mixing various inorganic conductive fillers (such as copper powder, silver powder, carbon black, etc.) into the matrix polymer have the most use value. The volume resistivity of the composites is adjustable in a large range, and many of them have been commercialized abroad. However, due to the poor dispersion of carbon black and other materials in plastics and poor compatibility with plastics, their application is also limited. Nano ATO powder has small particle size, good compatibility with plastics and light color, which widens the field of application of conductive powder in plastics. The main problems to be solved in the application of nano ATO powder in the anti-static of plastic surface are the relationship between the addition amount and the mechanical properties of the material, as well as the dispersion of nano powder in the matrix resin. For example, special processes such as skin core structure and multi-layer extrusion can be adopted, which requires the preparation of nano ATO conductive plastic masterbatch in advance

4 conclusion

nano ATO powder has significant advantages over traditional antistatic materials. It has broad application prospects and great development potential in the field of antistatic polymer materials. How to develop and make good use of these advantages of nano ATO and make it stand firmly in the market, the following aspects need to be further studied

1) agglomeration of nano ATO powder. From the current preparation level, no matter which method is used to prepare the powder, the particles tend to gather together to form secondary particles, or even tertiary particles, which greatly affects the performance of nano powders. Therefore, we must start with the agglomeration mechanism to explore a practical solution to the agglomeration problem of nano powder during preparation and storage

2) there are many reports on the preparation methods of nano ATO powder, but most of them are at the level of laboratory sample preparation. There are few methods that can really be industrialized and mass produced. Efforts need to be made to explore the best preparation methods and engineering amplification technology

3) actively explore new application fields of nano ATO powder to better contribute to improving people's living standards