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Characteristics and Application of Mica Powder

Release time:

2024-01-29 09:36

 

Characteristics and Application of Mica Powder

 

Mica powder is a layered structure of silicate, structure by two layers of silicon oxide tetrahedron sandwiched by a layer of aluminum oxide octahedron composed of double silicon oxide layer. Completely cleaved, it can be split into extremely thin flakes with a thickness of less than 1μm (theoretically it can be cut to 0.001μm) and a large diameter-thickness ratio. The crystal chemical formula of mica powder is: K0.5-1(Al,Fe,Mg)2(SiAl)4O10(OH)2▪NH2O, general chemical composition: SiO2: 43.13-49.04%, Al2O3: 27.93-37.44%,K2O + Na2O:9-11%,H2O: 4.13-6.12%.

 

1Features

 

Mica powder belongs to monoclinic crystal, the crystal is scaly, with silk luster (muscovite is glass luster), the pure block is gray, purple rose, white, etc., the diameter-thickness ratio is> 80, the specific gravity is 2.6-2.7, the hardness is 2-3, rich in elasticity, bendable, good in abrasion resistance and wear resistance; Heat-resistant insulation, insoluble in acid and alkali solution, stable in chemical properties. Test data: elastic modulus 1505-2134MPa, heat resistance 500-600oC, thermal conductivity 0.419-0.670W.(m.K)-1, electrical insulation 200kv/mm, radiation resistance 5 × 1014 thermal neutron/cm2 to illuminance. In addition, the chemical composition, structure and structure of mica powder are similar to kaolin, and it has some characteristics of clay minerals, that is, it has good dispersion and suspension in water medium and organic solvent, fine white particles and viscosity. Therefore, mica powder has a variety of characteristics of mica minerals and clay minerals.

 

2discrimination

 

The identification of mica powder is very simple. According to experience, there are roughly the following methods for your reference only:

First of all, the whiteness of mica powder is not high, about 75. Often received customer questions, reaction mica powder whiteness of about 90, under normal circumstances, mica powder whiteness is generally not high, only about 75. If mixed with other fillers such as calcium carbonate, talc, etc., the whiteness will be greatly improved.

Second, mica powder has a flaky structure. Take a beaker, add 100ml of purified water, and stir with a glass rod. It can be seen that mica powder has good suspension. Other fillers include transparent powder, talcum powder, calcium carbonate and other products, which are not as good as mica powder.

Third, get a little, coated on the wrist, a little pearlescent effect; mica powder, especially sericite powder, has a certain pearlescent effect, widely used in cosmetics, coatings, plastics, rubber and other industries. If the purchase of mica powder pearlescent effect is poor or without any pearlescent effect, at this time should pay attention.

 

3Application

 

CloudThe application of mother powder in coatings is mainly reflected in the following aspects:

1. The blocking effect of flake filler forms a basically parallel orientation arrangement in the paint film, and the penetration of water and other corrosive substances into the paint film is strongly blocked. In the case of using high-quality sericite powder (the diameter-thickness ratio of the wafer is at least 50 times, preferably more than 70 times), the penetration time of water and other corrosive substances through the paint film is generally prolonged by 3 times. Because sericite powder filler is much cheaper than seed resin, it has very high technical and economic value. The use of high-quality sericite powder is an important means to improve the quality and performance of anti-corrosion coatings and exterior wall coatings. During the coating process, the sericite wafer is subjected to surface tension before the paint film is cured and lies down, automatically forming a structure parallel to each other and parallel to the surface of the paint film. Such a layer-by-layer arrangement, its orientation is just perpendicular to the direction in which corrosive substances penetrate the paint film, and the barrier effect is most fully exerted.

2. Improve the physical and mechanical properties of the paint film The use of sericite powder can improve a series of physical and mechanical properties of the paint film. The key is the morphological characteristics of the filler, that is, the diameter-thickness ratio of the flake filler and the length-diameter ratio of the fibrous filler. The particle-packed filler is like sand and gravel in the concrete, which plays a reinforcing role in the reinforcement.

3, improve the anti-wear properties of the paint film The hardness of the resin itself is limited, and the strength of many fillers is not high (such as talc). On the contrary, sericite is one of the components of granite, and its hardness and mechanical strength are great. Therefore, the anti-wear performance can be significantly improved by adding sericite powder as filler in the coating. Most of the automotive coatings, pavement coatings, mechanical anti-corrosion coatings and wall coatings use sericite powder.

4, insulation performance sericite has a very high resistance, itself is the most excellent insulation material. With silicone resin or silicone boron resin to form a compound, encountered high temperature into a ceramic material with good mechanical strength and insulation performance, so the wire and cable made of this kind of insulating material, even after burning in a fire, still maintain the original insulation state. This is very important for mines, tunnels, special buildings, special facilities, etc.

5, flame retardant sericite powder is a very valuable flame retardant filler, if combined with organic halogen flame retardant, can be made of flame retardant and fire retardant coatings.

6, anti ultraviolet, infrared performance sericite has excellent shielding ultraviolet and infrared properties. Therefore, adding wet sericite powder to outdoor coatings can greatly improve the anti-ultraviolet performance of the paint film and delay the aging of the paint film. Its infrared shielding properties are used in the preparation of thermal insulation materials (such as paint).

7, thermal radiation and high temperature coating sericite has good infrared radiation ability, such as with iron oxide, can cause excellent heat radiation effect.

8. Sound insulation and shock absorption sericite can significantly change a series of physical modulus of the material, forming or changing the viscoelasticity of the material. Such materials efficiently absorb vibrational energy and attenuate vibration and sound waves. In addition, vibration waves and sound waves form repeated reflections between mica wafers, which also weakens their energy. Sericite powder is also used to formulate noise reduction, sound insulation, shock absorption coatings.

(2), white mica powder

The chemical formula of muscovite is KAl2(AlSi3O10)(OH)2, which has a continuous layered silica tetrahedral structure, has extremely complete cleavage, can be peeled off into elastic sheets, is flexible and bendable, transparent and colorless, thick translucent with gray, brown, light green and rose red, has glass to silk or pearl luster, hardness 2.5-3, specific gravity 2.75-3.0, and acid resistance.

Muscovite chemical composition: KAl2[Si3AlO10](OH,F)2, the ideal component is octahedral sheet containing Al, can also be a small amount of Fe 3, Mg, Fe 2 and even Mn, Cr, V and other replacement. Muscovite has a highly complete bottom cleavage, pale white color. The sheet is rich in elastic characteristics.

White mica powder is widely used in building materials industry, fire industry, fire extinguishing agent, welding rod, plastic, electrical insulation, paper, asphalt paper, rubber, pearlescent pigment and other chemical industries. Ultra-fine mica powder as plastic, paint, paint, rubber and other functional fillers, can improve its mechanical strength, enhance toughness, adhesion, anti-aging and corrosion resistance. In addition to high electrical insulation, resistance to acid and alkali corrosion, elasticity, toughness and sliding, heat resistance and sound insulation, small thermal expansion coefficient and other properties, it is the first to introduce the characteristics of smooth surface, large diameter to thickness ratio, regular shape, strong adhesion and so on.

(3) Synthetic mica

Synthetic mica wafer, also known as synthetic fluorine gold mica wafer, is made of chemical raw materials by high temperature melting, cooling crystallization, for the crystal typical layered silicate. It is a colorless, from ultraviolet to infrared (5um) good transparent material, breakdown strength decreases with the increase of mica sheet thickness (test conditions: AC 50Hz, planar electrode <φ25mm>, vertical cleavage surface). The vacuum gassing of synthetic mica wafers is extremely low, and the trace gases released are only O2, N2 and Ar adsorbed gases determined by mass spectrometry. Because it does not release water vapor, it is extremely valuable for use as an electric vacuum insulating material, which will greatly improve the service life of vacuum devices.

The product is pure white and transparent, high toughness and can be peeled off endlessly. It is a cutting-edge high-quality selected material, can be used for grinding high-end pearlescent mica powder, and is also the best substrate for manufacturing high-quality high-temperature insulation products.

Fluorophlogopite has excellent performance and is a good substrate for the preparation of synthetic mica paper, mica powder and pearlescent mica. Larger single crystals can also be made into temperature-resistant, corrosion-resistant window materials. Mica ceramic can be made into insulation high temperature skeleton, can also be made into chlorination furnace chlorine tube, furnace lining, etc. Mica powder can be used as high-grade coatings, synthetic diamond rod accessories, low hydrogen electrode accessories and many other fields.

Such as: insulating paper, insulating tape, insulating board, pearlescent mica powder, mica paper, mica tape, ceramics, coatings, plastics, paint, refractory materials, welding electrodes, aerospace, daily chemical supplies and other fillers.

(4), conductive mica powder

Conductive mica powder is based on wet muscovite, using nanotechnology, through surface treatment, semiconductor doping treatment, so that the substrate surface to form a conductive oxide layer, so as to produce a new type of electronic conductive functional semiconductor color (filler) material.

Conductive mica powder is scaly, its appearance is generally gray or light gray powder, with light color, easy to disperse, small proportion, heat resistance, high chemical stability, corrosion resistance, flame retardant, good wave permeability, good conductivity, low price. Sharing with color pigments can improve gloss without affecting its color, and can be used in conjunction with other pigments to make a variety of light, color, nearly white permanent conductive, anti-static products. It can be used in coatings to increase the elasticity of the paint film. Its horizontal arrangement in the coating can prevent ultraviolet radiation and protect the paint film, prevent cracking and prevent moisture penetration. It can improve the mechanical strength, powder resistance, temperature resistance, fire resistance, water resistance, impact resistance and durability of the paint film. It is especially suitable for anti-static oil tanks.

Conductive mica powder is suitable for almost any environment and occasions requiring conductive and anti-static. Add it to paint, plastic, rubber, adhesive, ink, cement, fiber, ceramic, with other pigments, easy to adjust into nearly white and other colors of permanent conductive, anti-static products, it can be widely used in petroleum, chemical industry, building materials, electronics, electromechanical, communications, automobiles, medicine, papermaking, textiles, packaging, printing, ships, ceramics, aerospace, weapons and other industrial sectors and people's daily life in the field of conductivity and anti-static.

Conductive Mica Powder Product Features

1. Excellent conductive performance of conductive mica powder.

2. The chemical properties of conductive mica powder are stable.

3. Conductive mica powder has light weight, easy to disperse and not easy to precipitate.

4. Conductive mica powder light color, easy to color.

 

Use

Coating field

Coating mica powder is a new type of functional green environmental protection filler, unique two-dimensional sheet barrier, UV shielding, chemical structure stability and other functions to effectively improve the coating resistance to penetration, weather resistance, wear resistance and corrosion resistance, in addition, does not contain any radioactive elements, leading the trend of green environmental protection in the field of coatings. It is widely used in exterior wall coatings, anti-corrosion coatings, powder coatings, high temperature resistant coatings, insulation coatings, waterproof coatings, road sign coatings, radiation protection coatings and some special coatings, such as ship coatings, spacecraft thermal control coatings and food utensils coatings.

  

Plastic field  

Plastic mica powder has the characteristics of high diameter-thickness ratio, high temperature resistance, acid and alkali resistance, wear resistance, etc., and is a natural functional powder filling material. The company selects high-quality mica ore and uses unique wet grinding, stripping and purification technology to process it. The mica layer is completely split and preserves the unique high diameter-thickness ratio structure of mica (diameter-thickness ratio is as high as 100 or more), which has outstanding reinforcement effect in plastic products and endows plastic products with excellent dimensional stability. The high temperature resistance of the product itself also greatly improves the Vicat softening point of the thermal deformation thermometer of the plastic, it is suitable for parts and products under high temperature conditions. Compared with glass fiber, mica has the characteristics of smooth surface and no warping and deformation. Products are widely used in PP, PA, PBT, PET and other plastic modification, functional masterbatch and plastic engineering applications.

Coatings are easy to age, heat and impact resistance are poor, which inhibit the application of plastics. Mica powder, its unique and excellent performance filled into the plastic, in reducing the shrinkage of products, warping degree and bending degree; improve the mechanical properties of products, heat resistance, insulation and chemical stability; increase product surface gloss; prevent plastic aging at the same time, but also expand the application field of plastic, improve the added value of mica powder. Using the basic characteristics of flake mica, the supersonic airflow crushing and surface chemical modification were carried out to change the properties of mica flakes, and the polyethylene reinforcement was prepared. The results show that the active flake mica improves the mechanical properties of polyethylene and has a reinforcing effect. The study found. Modified mica and PP have obvious synergistic effect, which can effectively improve the tensile strength, impact strength, bending strength, modulus, hardness and heat deformation temperature of PP. It was found that the application of mica powder as a new reinforcing filler in PVC was beneficial to reduce production costs and improve product quality for plastic processing enterprises. The study found that modified mica in nylon 6 modification, not only can enhance the rigidity of nylon 6, heat resistance, reduce molding shrinkage, but also can greatly reduce the production cost of nylon 6, is conducive to enhance the market competitiveness, is conducive to the expansion of market applications. The modified nylon 610 was prepared by multi-compound blending technology of cross-linking agent, mica powder and nylon 610. The results showed that moderate cross-linking and adding mica powder could improve the mechanical properties and electrical strength of nylon 610 resin, and the content of cross-linking agent and mica powder in the modified nylon 610 was 5% and 10% respectively. The surface of muscovite was modified by silane coupling agent, and the composite material was prepared by compounding with acrylonitrile butadiene styrene copolymer (ABS). The results show that muscovite is distributed in ABS with lamellar structure, which can effectively improve the stiffness of ABS, and can greatly reduce the cost on the basis of maintaining good comprehensive mechanical properties.The modified polyaryletherketone filled with mica in Lingshou County was treated with phthalic acid. It was found that the modified mica could significantly improve the tensile strength, tensile elastic modulus and elongation at break of polyaryletherketone. It was found that when mica was used to fill polyolefin, polyester, polyamide, polyurethane and other polymer materials, the tensile strength, tear strength and Shore hardness of the composites were improved to varying degrees. The composite material made by mixing mica with thermoplastic resin or thermosetting resin is a kind of engineering plastic with wide application.

 

Electronic field  

Mica powder is a new type of special functional filler, applicable to the technical requirements of copper clad laminate industry, can replace the use of electronic grade silicon powder, giving the plate more ideal insulation, rigidity, low expansion rate, drilling processability, heat resistance and process stability and other properties. The material has complete chemical inertness, even at high temperature and complex system will not crack metamorphism or induced reaction, especially with greatly improve the drilling efficiency, drilling quality and reduce the characteristics of drill bit wear, is gradually becoming a hot material in the copper clad laminate industry.

    

Rubber field   

Mica powder is an excellent rubber filling reinforcing material. Its unique structure with high diameter to thickness ratio improves the reinforcing effect, and its excellent flaky crystal shape greatly improves the air tightness. Its own mineral crystal polarization effect and interlayer water molecular interference effect effectively shield ultraviolet, microwave and infrared rays, and greatly improve the aging resistance of products. The application results of Beijing Rubber Research Institute, Henan Tire Factory, Sichuan Rubber Factory and other manufacturers in tires, adhesive tapes, rubber sheets, rubber hoses, automobile rubber accessories and other products prove that sericite powder has good processing performance and can replace 30-50% of semi-reinforced or other coarse particle carbon black, or add a certain proportion of sericite powder to the original formula, which can keep the rubber material performance unchanged and reduce the product cost at the same time.

 

Refractory field

In the field of refractory materials, mica powder has the advantages of stable main mineral content, moderate refractoriness, stable physical and chemical properties of insulation and heat insulation, good adhesion of clay, no expansion, fast drying speed, good plasticity, and strong resistance to iron flow erosion.

 

 

Welding rod field

Mica powder in the field of welding materials is a new type of electrode coating material. Its unique combination of chemical elements can improve arc stability, reduce spatter, improve the process performance of electrode, and solve the problem of electrode coating cracking that often occurs in the production process of electrode. When applied in acid electrodes such as E4303 and E4313, the recommended ratio is 3%-5%, at the same time, it has a certain elasticity, plasticity, can increase the slipperiness of the electrode coating and the fluidity in the powder cylinder, improve its pressure coating performance, replace titanium dioxide, and reduce the cost of the electrode.

 

ceramic industry

Mica ceramic is a special engineering material, which is suitable for the production of heat-resistant materials, insulating materials, high-temperature mechanical parts, etc., and is widely used in electrical and electronic industries. Mica ceramics are generally made by crystallizing glass or sintering. However, the flexural strength of mica ceramics produced by these two processes is not ideal. For example, the glass crystallization method of mica ceramics, the flexural strength is generally only in the range of 100 ~ 140MPa, sintering method of mica ceramics, the flexural strength in the range of 120 ~ 130MPa. In order to significantly improve the strength characteristics of mica ceramics, a foreign company through painstaking development, invented a production of high-strength mica ceramic ingredients. According to reports, the ingredients are made of phlogopite and alumina as the main raw materials, mixed with barium fluoride and calcium fluoride admixture. The strength characteristics can be effectively improved with this ingredient, so that the flexural strength of mica ceramics exceeds 160MPa. In order to evaluate the properties of high strength mica ceramics, the company conducted the following tests. According to the proportion given in Table 1, add appropriate amount of water, mix and grind in a ball mill for 24 hours to prepare the mixture, press into a round test body under a pressure of 75MPa, fill in fluorine gold mica powder, sinter at 1280 ℃, 1340 ℃ and 1300 ℃ for 1 hour respectively, cool, and measure the flexural strength, machinability, thermal expansion coefficient and electrical properties of the sintered test body. The measurement results show that the mica ceramic not only maintains the inherent characteristics, but also has good processability, and more importantly, the flexural strength is significantly improved. Therefore, its use performance is better.

 

 

 

 

 

 

Characteristics, mica powder, mica, coatings, strength, improvement, performance, materials, ceramics, conductivity

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