Current Application Status of Silica Sol in Various Fields

Silica sol is widely used in various fields. The production capacity of silica sol in China has reached nearly 600000 tons, and it has developed rapidly in recent years. It is mainly used in precision casting, refractory materials, coatings, catalysts, papermaking, and other fields. With further research on the application of silica sol, the application of silica sol will be further expanded, which will further improve the development speed of silica sol.

1. Application of silica sol in precision casting

Silicone sol is mainly used as a binder for precision casting coatings, and can be used as a surface layer coating and reinforcement layer coating for mold shells. Applying small particle silica sol to precision casting instead of ethyl silicate can not only reduce costs but also improve working conditions. When used for precision casting of thin shells, it can achieve high shell strength, high dimensional accuracy, good casting smoothness, better quality than sodium silicate, and lower price than ethyl silicate. This is particularly suitable for castings with high surface finish requirements for large castings, as well as castings that require no or less allowance. Using silica sol as a high-temperature resistant coating for molds can improve the coating's heat resistance and wear resistance, reduce the loss of molten metal to the mold at high temperatures, and aid in demolding.

2. Application of silica sol in textiles

In the textile industry, fabrics treated with silica sol have high strength, stable fabric size, and high recovery elasticity; The combination of silica sol and synthetic wool oil increases the adhesion between fibers, enhances the tensile strength, improves production efficiency, and can spin high count products.

In the process of wool spinning, silica sol is used as an auxiliary agent for radial spinning and sizing to reduce the breakage rate of wool fibers. The coating contains titanate fibers, and silica sol can increase the surface thermal resistance of inorganic fiber materials. The dosage of silica sol is generally controlled at 2-5%. The best way to add people is to add them to wool and fine short hair for the first time, but the silica sol contains a certain amount of water, which needs to be included in the machine's moisture regain.

Adding silica sol to the sizing of diameter yarn can reduce breakage and save sizing material: When using fine grain rolling or twisting for sizing, adding silica sol to slurries such as polyvinyl alcohol, carboxymethyl cellulose, natural starch, and oil can make diameter yarn separation easy, prevent slipping, and continuously yarn. The net knot of the woven nylon fishing net is firm and not easy to slide and loosen; Nylon rope treated with silica sol can increase the friction between monofilaments, prevent slipping, and reduce its elongation; Bedding materials made of synthetic fibers are generally relatively smooth. If fibers treated with silica sol are used, a fluffy, elastic, and non slippery bedding can be obtained. Treating chemical fibers with silica sol can also achieve extinction effect.

Silicone sol can also be used in fabric dyeing. Because it has adhesive properties and can form an excellent protective solution, it helps pigments adhere to the surface of fabrics, increases dyeing uniformity and fastness, and prevents pigment agglomeration; Adding 60% silica sol with pigment content to starch glue can be used to treat fabrics such as carpets, which can prevent slipping, dust, static electricity, and dust.

3. Paper making

When producing artificial fibers and fiberglass, using silica sol as a binder can prevent adhesion and rolling in between films; The photosensitive paper is mixed with silica sol and photosensitive liquid for processing, which can make the photosensitive paper surface smooth, the image vivid, and increase the exposure range to produce one-step imaging paper; A pre coating used for printing paper, photocopying paper, and offset printing, which can make the paper surface smooth, image contrast clear, and have good contrast. After treating the surface of kraft paper and corrugated paper with silica sol, the slip resistance of the paper can be improved, the sliding during transportation and storage can be reduced, and the temperature resistance and strength of the paper can be improved. In the manufacturing of non carbon copy paper, using silica sol instead of clay, talc powder, and silica powder coatings can make its color more vivid; Plastic films and glass paper are prone to sticking in summer. If treated with a mixture of silica sol and monostearic acid glyceride, it can be successfully resolved. Perforated paper used in electronic computers, coated with silica sol, can have high stability, slip resistance, and good printability.

4. Catalyst

In catalyst production, silica sol serves as a carrier under certain conditions to accelerate the catalytic speed and improve production efficiency. Its advantages are that it has no other by-products, salts, etc., and can obtain a certain specific surface area. At the same time, Si0 has a high content, high processing efficiency, and good selectivity and activity. Si0， The silica sol with a concentration of 40% has been successfully used as a carrier for the production of propylene cyanide catalyst C-41. Other carriers include benzene oxidation as a maleic anhydride carrier and the synthesis of methyl methacrylate; Chlorination of carbon hydrogen compounds; Dehydrogenation of alcohols can be used as a carrier. Industrial production often has different requirements for the particle size, specific surface area, pore size, pore volume, and stiffness of catalyst carriers. For example, in fixed bed reactions, due to the limitation of fluid resistance, the use of large particle carriers is required; In the vulcanization bed, it is required to use fine particle carriers to improve efficiency; Molybdenum bismuth catalyst for ammonia oxidation of propylene requires a carrier particle size of around 50 microns; The microsphere catalyst used for catalytic cracking of petroleum fractions requires a particle size of around 60 microns.

5. Using silica sol as a silica sphere

In the mixture of urea and formaldehyde, there are inorganic particles of silica sol (Si0,). Due to the copolymerization of organic matter urea and formaldehyde, the urea formaldehyde copolymer and the colloidal particles in the solution copolymerize into spherical particles

6. Petroleum

The use of silica sol as a monomer catalyst in the production of aromatic cyanide has opened up a new way to improve the recovery rate of aromatic cyanide. Silicone sol is used in several sets of petrochemical joint plants introduced in China. In the petroleum industry, silica sol is used as a binder and catalyst.

7. Coatings

Silica sol is widely used as exterior wall building coatings, which have advantages such as water and weather resistance, fire resistance, pollution resistance, high temperature resistance, high film hardness, bright and non fading color. It can also be used for acid, alkali, fire, drainage coatings, and infrared radiation coatings.

8. Enamel

In the manufacturing of enamel ware, the addition of silica sol can reduce the coefficient of expansion and improve the adhesion to tetrafluoroethylene. By adding 25-30% silica sol into glass, high-quality silicate glass can be obtained.

9. Battery

The electrolyte sulfuric acid of lead-acid batteries is prone to overflow during sharp turns in vehicles such as cars and tanks. If a certain amount of silica sol is added to the sulfuric acid to gelatinize it, it can prevent sulfuric acid leakage and overflow, and prolong the life of the battery.

10. Metals

Silicone sol can be used to prevent white embroidery on galvanized sheets. Insulation film treatment for electromagnetic steel plates, sealing treatment for corrosion-resistant aluminum, surface grinding treatment, and oxidation inhibitor during heat treatment.

11. Rolling steel

Adding a certain amount of silica sol to the coating solution can improve the appearance, insulation performance, heat resistance of the insulation coating, reduce the coefficient of expansion of the coating material, and improve the magnetism of silicon steel.

12. Broadcasting equipment

Silicone sol can be used as a coating for bonding television tubes; When making transformer magnetic cores, it is used as a bonding agent to bond the silicon steel sheets together, and has the effect of insulation, high temperature resistance, and improving melting point, which is very effective.

13. The use of silica sol as a far-infrared radiation coating has good adhesion, high temperature resistance, and does not affect radiation.

14. Using silica sol as a binder for ceramic fibers

Soak aluminum silicate fiber felt in silica sol, add a coagulant, and make it into a warm felt. It is used as a thermal insulation refractory material and as a surface binder for refractory bricks in high-temperature furnaces. It has high bonding strength, high temperature resistance (above 1000 ℃), energy conservation, and is both economical and convenient for furnace renovation.

15. Semiconductor component polishing agent

Using large particle silica sol as a single crystal silicon polishing agent not only has a good effect but also a fast polishing speed.

16. Reinforced foam rubber

Natural rubber and the vast majority of synthetic rubber, such as styrene butadiene rubber, chloroprene rubber, and blends, can be reinforced with silica sol. Adding 5% silica sol into dry rubber can enhance porous foam rubber by 20%; For a certain volume of rubber, 20% of the rubber can be saved due to the increase of elasticity, and the addition of silica sol in the beating operation can also improve the foam performance and produce more stable wet foam. In addition, foam rubber can be prepared first and then treated with silica sol.

17. Silica sol can be used as a clarifying agent for soy sauce and rice wine, without affecting color, aroma, and taste. Silicon is non-toxic to the human body and has certain anti-cancer and anti-cancer effects.

18. Carbon products treated with silica sol can reduce losses caused by surface oxidation.

19. Chemical fiber decorative items treated with silica sol can double their anti pollution properties, indicating that silica sol is also an effective anti fouling agent on the surface of wall decoration fabrics and other materials.

20. Anti slip floor wax made from silica sol is well-known in industry and civil use. The small Si0 particles adhere to the wax film on the floor surface, resulting in good anti slip effect and not affecting the soft gloss.

21. Silica sol is an excellent water purifier. It can coagulate and remove metal salts and suspended solids in water by adding aluminum sulfate.

Adding a small amount of silica sol to fuel oil can prevent the accumulation of combustion ash on the diesel engine.

23. Application of silica sol as fertilizer for drip irrigation and sprinkler irrigation water-soluble fertilizers.