In our daily life, in fact, many of the products we use are chemical products, but we do not know that we are using chemical products, but this does not hinder my curiosity. Today, I want to know what is silica? What? Silica is mainly used in which areas?
What is silica?
This is an inorganic material that can be added to many places! Silica is mainly used in which areas? Then there are more, glass, water glass, pottery, enamel, refractory, aerogel felt, ferrosilicon, molding sand, elemental silicon, cement, etc. all have its existence.
Silica is mainly used in which areas?
All summaries are in the first person, starting from oneself. It is a reflection of the unit or individual’s own practice, its content and writing come from their own practice, and its conclusions are also to guide their own practice in the future.
1. Application in the rubber industry
Rubber is an elastomer with excellent stretchability, but its comprehensive properties are not satisfactory. In the process of producing rubber products, carbon black is usually added to the rubber compound to improve strength, wear resistance and aging resistance. The addition of black makes the products all black, and the grade is not high. The advent of silica in my country has laid a material foundation for the production of a new generation of rubber products with novel colors and excellent performance. After adding a small amount of silica to ordinary rubber, the strength, wear resistance and anti-aging properties of the product reach or exceed that of high-grade rubber products, and the color can remain unchanged for a long time.
In the rubber industry, silica is usually used in vulcanized silicone rubber, medical rubber products, tires, hoses, tapes and daily necessities (rubber shoes, electrical appliances and stationery).
2. Application in the plastics industry
In thermoplastics, fumed silica can improve the toughness of plastics. After it is added to plastics, it can improve the toughness of the material without weakening the rigidity of the material, and even improve the rigidity of the material.
In thermosetting plastics, adding fumed silica to epoxy resin can significantly improve its brittleness, overcome the defects of material rigidity and strength reduction caused by elastomer toughening, and achieve the purpose of strengthening and toughening.
In plastics, silica can also be used as a flame retardant. Since fumed silica improves the strength of the carbon-silicon layer through the physical process in the condensed phase, it can prevent the transfer of heat and materials during combustion.
3. Application in coatings
In light-curing coatings, nano-silicon dioxide is filled into UV-curing coatings, so that the hardness of the coatings after curing is significantly improved, and the heat resistance is also improved. At the same time, it can improve the curing speed, coating hardness, adhesion and thermal stability at low temperature of UV-curable coating.
In addition, adding silica to plastic and metal coatings can significantly improve the performance of the materials.
4. Application in the field of ceramics
First, silica is the main component of quartz ceramics. Secondly, as an additive, it can also effectively enhance the performance of ceramics. For example, adding silicon dioxide instead of nano-Al2O3 to 95 porcelain can not only play the role of nanoparticles, but also the second phase particles, which not only improves the strength and toughness of the ceramic material, but also improves the hardness and hardness of the material. Elastic modulus and other properties, its effect is more ideal than adding Al2O3.
The use of silicon dioxide to composite ceramic substrates not only improves the compactness, toughness and smoothness of the substrates, but also greatly reduces the sintering temperature. In addition, the application effect of silica in ceramic filters, corundum balls and other ceramic products is also very significant.
5. Application in electronic packaging
The three main materials of electronic packaging are substrate material, plastic sealing compound, lead frame and solder. Among plastic encapsulants, epoxy encapsulant (EMC) is the mainstream of integrated circuit packaging at home and abroad. In EMC, the content of silica fine powder accounts for 60% to 90%. In electronic packaging, high moisture resistance, low stress, low alpha ray, resistance to dip soldering and reflow soldering, and good plastic packaging process performance are mainly required after integrated circuit packaging. In response to these requirements, the epoxy molding compound must be doped with inorganic fillers in the resin matrix. The inorganic fillers currently used are basically silicon micropowder, which can reduce the thermal expansion coefficient of the molding compound, increase thermal conductivity, reduce dielectric constant, and environmental protection. , flame retardant, reduce internal stress, prevent moisture absorption, increase the strength of the plastic packaging material, reduce the cost of packaging materials and so on.
6. Application in sealants and adhesives
Sealants and adhesives are important products with a large amount, a wide range and a wide range of applications. It requires optimum conditions for product viscosity, fluidity, and curing speed. my country’s products in this field are relatively backward, and high-grade sealants and adhesives are all dependent on imports. Foreign products in this field have used nanomaterials as modifiers, and silica is the preferred material. It mainly coats a layer of organic material on the surface of silica to make it hydrophobic, and adds it to the sealant. A kind of silica structure is formed very quickly, that is, the small silica particles form a network structure to inhibit colloidal flow, speed up the curing speed, and improve the bonding effect. Due to the small size of the silica particles, it also increases the sealing and impermeability of the product. .