Application of ultrafine silicon micropowder in plastics, rubber and coatings
Application of ultrafine silicon micropowder in plastics, rubber and coatings
Non-metallic mineral fillers play an important role in modern polymer materials such as plastics, rubber and paints. Adding non-metallic mineral fillers to the polymer base can not only reduce the cost of the polymer material, but more importantly, improve the performance and dimensional stability of the material, and impart certain special physical and chemical properties to the material, such as compression resistance. , impact resistance, corrosion resistance, flame retardant, insulation and so on. As a filler for polymer materials such as plastics, rubber, paints, etc., silicon micropowder processed by powder quartz has attracted more and more attention in ultrafine pulverization, purification, modification and application.
1 , Application of silicon micropowder in plastics
Silicon micropowder can be used in plastics such as polyvinyl chloride (PVC) flooring, polyethylene and polypropylene film, and electrical insulation materials. The PVC floor tile filled with silicon micropowder can enhance the wear resistance of the product. In the PVC floor, the fineness of 320 mesh quartz powder, the filling amount is 160-180 parts, the floor is fully meet the requirements of GB4085-83 standard. The surface of the floor has good smoothness and good scratch resistance.
In the PVC acid-resistant tube, when the filling amount of 400 mesh quartz powder is 10% to 15%, compared with other fillers, the viscosity is low, the fluidity is good, the processing performance is improved, and the extrusion and molding of the product are facilitated. The acid resistance of the obtained acid-resistant tube has been significantly improved. A silicon micropowder filled polyethylene (PE) agricultural film with a large specific surface area (above 600 mesh) and high activity can improve the physicochemical properties and optical properties of the product, and filling the polypropylene can improve the mechanical properties of the product.
After the application of powdered quartz in PE film, the powder quartz ore was superfinely graded, purified, surface modified and filled in PE film. The use of quartz has the function of blocking infrared rays to slow the heat loss of plastic greenhouse. To improve its insulation performance. Through research, when ultrafine powder quartz is added in the PE film by 8% to 12%, the processing property is good, the filler has good dispersion and fluidity in the resin, and the distribution is uniform. The mechanical properties of the prepared PE film are close to the pure resin film, exceeding National standard requirements.
In the use of insulating materials, silicon micropowder is used as a filler in epoxy molding compound, and SIEC special high pressure epoxy mold with excellent electrical properties, high pressure resistance, excellent arc resistance, high surface resistivity and weather resistance has been developed. Plastic, the plastic is the material of choice for high voltage insulators and high voltage switches.
In the preparation of epoxy film plastics, the amount of silicon micropowder accounts for 50% to 70% of the molding compound, and the plastic is a good new packaging material for low-voltage electrical appliances such as electromagnets for packaging valves.
2 , Application of silicon micropowder in rubber
In order to improve the physical and mechanical properties of rubber products and prolong the service life of rubber products, two methods are generally used: one is to embed the skeleton material in the rubber product, such as fiber textile material or metal material; the other is to add in the rubber. Various fillers.
As a rubber reinforcing material, silicon micropowder has the following forms:
(1) Powder quartz. It is mainly made of natural diatomaceous earth, which is pulverized, calcined at high temperature and removes organic impurities. It can be used in rubber to make the rubber firm, reduce the density of rubber and increase the thermal insulation performance. It is suitable for the manufacture of insulating rubber compound and model. Products and foam products for hard rubber to increase the softening temperature.
(2) Silica powder. The content of silica is 75% to 79%. The natural minerals are mined, dried, pulverized and sieved. They can be used for hoses, tapes and other rubber products. The rubber compound is easy to mix and disperse, and it can be filled with high dosage. The surface of the calendered product is smooth, and its vulcanized rubber has a tensile strength close to that of clay, and is comparable to light calcium; the adhesion strength and the torn permanent deformation are superior to the clay, the wear resistance and elasticity are superior to the clay and light calcium; the aging performance is good, The price is lower than clay and light calcium.
(3) Quartz powder. Quartz powder has different types such as amorphous and microcrystalline, and is made by crushing natural minerals.
In terms of specific application, in the battery shell, powdered quartz is added instead of clay and light calcium carbonate, the filling amount is increased from 55% to 65%, and the process performance is excellent, the rubber powder is fast, no dusting and flying phenomenon. It is easy to mix and practice, and has good vulcanization performance. The physical and mechanical properties such as acid resistance, voltage resistance, thermal deformation and ball drop impact of the battery shell can be achieved, and the appearance of the rubber shell is smooth and the yield is improved.
In the rubbing rubber products, the mixing rubber filled with powder quartz, the rubber compound is thin, the permeability is good, and the blocking property is strong, which is beneficial to the rubbing of the kneading glue on the canvas, and enhances the adhesion strength between the film and the canvas. The mechanical properties such as tear strength and permanent deformation of the product are obviously improved. In the patented electrical insulating sealing film, Xu Mei added silane rubber as the base material and added silicon micropowder. The obtained film has high dielectric strength, waterproof, heat resistance, cold resistance, chemical corrosion resistance, anti-aging, good plasticity and insulation. Good characteristics, suitable for 0.4 ~ 10kV wire busbars and insulation seals of all types of electrical exposed joints.
3 , Application of silicon micropowder in coatings industry
In the coating industry, the characteristics of particle size, whiteness, hardness, suspension, dispersibility, low oil absorption and high electrical resistivity of silicon micropowder can improve the corrosion resistance, wear resistance, insulation and high temperature resistance of the coating. Used in coatings, silicon micropowder has always played an important role in coating fillers due to its good stability. Especially for exterior wall coatings, SiO2 raw materials play an important role in weather resistance.
With the growing prosperity of the construction market, the coatings industry has also developed rapidly, and the amount of silicon micropowder has also increased. At the same time, higher requirements have been placed on the ultrafine and modified silicon micropowder.
Silicon powder is added to the exterior wall wiper paint for good exterior wall decoration, erosion resistance and low cost. At the same time, the research and application of nano-scale SiO2 has received more and more attention.
In the application of special coatings, 1250 mesh silicon micropowder is coated with SnO2 on the surface by chemical coprecipitation technology to produce composite conductive powder, which is widely used in electronic and electrical, aerospace, military and electromagnetic shielding. The conductive paint prepared by using the conductive powder has a volume resistivity of only 12.6 Ψ·cm, and all the indexes reach the national standard.
In the flame-retardant insulating coating, the thixotropic property of the coating is improved by adding silicon micropowder, which has the characteristics of uniform coating, no cracking, short curing time and low cost.
In the non-toxic epoxy toughening coating, epoxy powder was added into the epoxy resin to develop a non-toxic epoxy toughening coating with anti-corrosion function, which overcomes the defects and deficiencies of the existing coatings at low temperature.
With the continuous development of plastics, rubber and coatings industry, non-metallic mineral fillers such as silicon micropowder should not only be continuously researched in ultra-fine, purification and modification technologies, but more importantly, ultra-fine powders should be carried out at these high levels. Applied research in molecular polymers to advance the entire industrial technology.