The role of barium sulfate, mica powder and kaolin in powder coatings
Fillers in powder coatings can not only reduce costs, but also play a great role in improving the performance of coating products. Such as improving the wear resistance and scratch resistance of the coating, reducing the sagging of the coating during melt leveling, improving corrosion resistance, and improving moisture resistance.
When selecting fillers for powder coatings, factors such as density, dispersion performance, particle size distribution, and purity need to be considered. Generally speaking, the higher the density, the lower the coverage of the powder coating; the dispersion of large particles is better than that of small particles; the filler is chemically inert and can avoid reacting with certain components of the powder formula such as pigments; the color of the filler should be as white as possible. The filler powder materials commonly used in powder coatings are mainly calcium carbonate, barium sulfate, talc, mica powder, kaolin, silica, wollastonite, etc.
Application of barium sulfate in powder coatings
Barium sulfate used as a pigment in coatings is of two types: natural and synthetic. The natural product is called barite powder, and the synthetic product is called precipitated barium sulfate.
In powder coatings, precipitated barium sulfate can enhance the leveling and gloss retention of powder coatings, and has good compatibility with all pigments. It can make powder coatings achieve ideal coating thickness and high powder coating rate in the spraying process.
Barite powder filler is mainly used in industrial primers and automotive intermediate coatings that require high coating strength, high filling power and high chemical inertness, and is also used in topcoats that require higher gloss. In latex paint, due to the high refractive index of barite (1.637), fine barite powder can have the function of translucent white pigment and can replace part of titanium dioxide in coatings.
Ultrafine barium sulfate has the characteristics of large filling amount, good brightness, good leveling, strong gloss retention and good compatibility with all pigments. It is the most ideal filler for powder coatings.
Application of mica powder in powder coatings
Mica powder is a complex silicate composition, the particles are scaly, heat resistance, acid and alkali resistance are excellent, and it affects the melt fluidity of powder coatings. It is generally used in temperature-resistant and insulating powder coatings and can be used as a filler for texture powder.
Application of Kaolin in Powder Coatings
Kaolin can improve thixotropy and anti-sedimentation properties. Calcined clay has no effect on rheological properties, but it can have matting effect, increase hiding power and increase whiteness like untreated clay, which are similar to talcum powder.
Kaolin generally has high water absorption and is not suitable for improving the thixotropy of coatings and preparing hydrophobic coatings. The particle size of kaolin products is between 0.2 and 1 μm. Kaolin with large particle size has low water absorption and good matting effect. Kaolin with small particle size (less than 1 μm) can be used for semi-gloss coatings and interior coatings.
Kaolin is also called hydrated aluminum silicate. According to different processing methods, kaolin can be divided into calcined kaolin and washed kaolin. Generally speaking, the oil absorption, opacity, porosity, hardness and whiteness of calcined kaolin are higher than those of washed kaolin, but the price is also higher than that of washed kaolin.
14 Applications of White Carbon Black
Application in tires
Silica is used as a reinforcing agent, and the largest amount is in the rubber field, accounting for 70% of the total amount. Silica can greatly improve the physical properties of the rubber, reduce the hysteresis of the rubber, and reduce the rolling resistance of the tire without losing its anti-skid property.
Application in defoamers
There are generally two types of fumed silica: hydrophilic and hydrophobic. The hydrophobic product is obtained by surface chemical treatment of the hydrophilic product.
Application in paint and coating industry
Silica can be used as a rheological additive, anti-settling agent, dispersant, and matting agent in coating production, playing the role of thickening, anti-settling, thixotropy, and matting. It can also improve the weather resistance and scratch resistance of the coating, improve the adhesion strength between the coating and the substrate and the hardness of the coating, improve the aging resistance of the coating, and improve the ultraviolet absorption and infrared light reflection characteristics.
Application in electronic packaging
By fully dispersing the surface-active treated fumed silica in the silicone-modified epoxy resin encapsulation glue matrix, the curing time of the encapsulation material can be greatly shortened (2.0-2.5h), and the curing temperature can be reduced to room temperature, so that the sealing performance of the OLED device is significantly improved
Application in plastics
Silica is also often used in new plastics. Adding a small amount of silica during plastic mixing will produce a significant reinforcement effect, improve the hardness and mechanical properties of the material, thereby improving the processing technology and the performance of the product.
Application in ceramics
Using fumed silica instead of nano-Al2O3 to add to 95 porcelain can not only play the role of nanoparticles, but also be a second-phase particle, which not only improves the strength and toughness of ceramic materials, but also improves the hardness and elastic modulus of the material. The effect is more ideal than adding Al2O3.
Application in the papermaking industry
In the papermaking industry, fumed silica products can be used as paper sizing agents to improve the whiteness and opacity of paper, and to improve oil resistance, wear resistance, hand feel, printing, and gloss. It can also be used for drying drawings, which can make the surface quality of paper good, the ink stable, and the back without cracks.
Application in toothpaste
Precipitated silica is the main type of friction agent for toothpaste at present. Precipitated silica has a large total specific surface area, strong adsorption capacity, more adsorbed substances, and uniform particles, which is conducive to improving transparency. Because of its stable properties, non-toxic and harmless, it is a good toothpaste raw material.
Application in cosmetics
The excellent properties of silica such as non-toxicity, odorlessness, and easy coloring make it widely used in the cosmetics industry. Silica is used in skin care products and cosmetics to make the skin feel smooth and soft ("ball bearing effect"), and the "soft focus effect" produced makes the light irradiated on the skin surface evenly distributed, so that wrinkles and blemishes on the skin are not easily detected.
Application of white carbon black in rubber shoes
White carbon black has high blackness and fine particles. The vulcanized rubber made with transparent white carbon black has high transparency and can improve the comprehensive physical properties of the rubber.
Application in the pharmaceutical industry
White carbon black has physiological inertness, high absorbability, dispersibility and thickening properties, and has been widely used in pharmaceutical preparations.
Application in ink
Silica is also used to control the flow of printer ink so that it cannot flow or sag arbitrarily to obtain clear printing. In beverage cans, it controls the use of high-speed spray coating. Fumed silica is also used as a dispersant and flow control agent in the toner of copiers and laser printers.
Application in pesticides
Silica can be used in pesticides for herbicides and insecticides. Adding a small amount of fumed silica and precipitated silica to the mixture of two common herbicides, dinitroaniline and urea, will prevent the mixture from agglomerating.
Application in daily necessities
Food packaging bags with silica added can keep fruits and vegetables fresh. White carbon black can also be used as a highly effective fungicide to prevent and treat various diseases of fruits; in the production of alcoholic beverages, adding a small amount of white carbon black can purify beer and extend the shelf life.
Powder surface modifier
Surface coating modification means that the surface modifier has no chemical reaction with the particle surface, and the coating and the particle are connected by van der Waals force. This method is applicable to the surface modification of almost all kinds of inorganic particles. This method mainly uses inorganic compounds or organic compounds to coat the surface of the particles to weaken the agglomeration of the particles. In addition, the coating generates steric repulsion, which makes it very difficult for the particles to re-agglomerate. The modifiers used for coating modification include surfactants, hyperdispersants, inorganic substances, etc.
Surface chemical modification is completed by chemical reaction or chemical adsorption between the surface modifier and the particle surface. Mechanochemical modification refers to a modification method that changes the mineral lattice structure, crystal form, etc. through mechanical methods such as crushing, grinding, and friction, increases the internal energy of the system, increases the temperature, promotes the dissolution of particles, thermal decomposition, generates free radicals or ions, enhances the surface activity of minerals, and promotes the reaction or mutual adhesion of minerals and other substances to achieve the surface modification goal.
The precipitation reaction method is to add a precipitant to a solution containing powder particles, or to add a substance that can trigger the generation of a precipitant in the reaction system, so that the modified ions undergo a precipitation reaction and precipitate on the surface of the particles, thereby coating the particles. The precipitation method can be mainly divided into direct precipitation method, uniform precipitation method, non-uniform precipitation method, co-precipitation method, hydrolysis method, etc.
Capsule modification is a surface modification method that covers the surface of powder particles with a uniform and certain thickness of film. High-energy modification method is a method of modifying by initiating polymerization reaction by plasma or radiation treatment.
There are many types of surface modifiers, and there is no unified classification standard yet. According to the chemical properties of the surface modifier, it can be divided into organic modifiers and inorganic modifiers, which are used for organic surface modification and inorganic surface modification of powders respectively. Surface modifiers include coupling agents, surfactants, polyolefin oligomers, inorganic modifiers, etc.
The surface modification of powders is largely achieved through the action of surface modifiers on the surface of powders. Therefore, the formulation of surface modifiers (variety, dosage and usage) has an important influence on the modification effect of powder surface and the application performance of modified products. The formulation of surface modifiers is highly targeted, that is, it has the characteristics of "one key to open one lock". The formulation of surface modifiers includes the selection of varieties, determination of dosage and usage.
Varieties of surface modifiers
The main considerations for selecting surface modifier varieties are the properties of powder raw materials, the purpose or application field of the product, and factors such as process, price and environmental protection.
Dosage of surface modifiers
Theoretically, the dosage required to achieve monolayer adsorption on the particle surface is the optimal dosage, which is related to the specific surface area of the powder raw materials and the cross-sectional area of the surface modifier molecules, but this dosage is not necessarily the dosage of surface modifiers when 100% coverage is achieved. For inorganic surface coating modification, different coating rates and coating layer thicknesses may show different characteristics, such as color, gloss, etc. Therefore, the actual optimal dosage should be determined through modification tests and application performance tests. This is because the dosage of the surface modifier is not only related to the uniformity of the dispersion and coating of the surface modifier during surface modification, but also to the specific requirements of the application system for the surface properties and technical indicators of the powder raw materials.
How to use the surface modifier
A good method of use can improve the dispersion of the surface modifier and the surface modification effect of the powder. On the contrary, improper use may increase the dosage of the surface modifier and the modification effect will not achieve the expected purpose. The usage of the surface modifier includes the preparation, dispersion and addition methods, as well as the order of adding when using more than two surface modifiers.
What are the uses of titanium dioxide?
Titanium dioxide is an important inorganic chemical pigment, the main component of which is titanium dioxide. There are two production processes for titanium dioxide: sulfuric acid process and chlorination process. It has important uses in industries such as coatings, inks, papermaking, plastics and rubber, chemical fibers, and ceramics.
The particle size distribution of titanium dioxide is a comprehensive indicator, which seriously affects the performance of titanium dioxide pigment and product application performance. Therefore, the discussion of hiding power and dispersibility can be directly analyzed from the particle size distribution.
The factors affecting the particle size distribution of titanium dioxide are relatively complex. The first is the size of the original hydrolysis particle size. By controlling and adjusting the hydrolysis process conditions, the original particle size is within a certain range. The second is the calcination temperature. During the calcination of metatitanic acid, the particles undergo a crystal transformation period and a growth period. Control the appropriate temperature to keep the growing particles within a certain range. Finally, the product is crushed. Usually, the Raymond mill is modified and the analyzer speed is adjusted to control the crushing quality. At the same time, other crushing equipment can be used, such as: universal mill, air flow mill and hammer mill.
Titanium dioxide has three crystal forms in nature: rutile, anatase and brookite. The brookite belongs to the orthorhombic system and is an unstable crystal form. It will transform into rutile at above 650°C, so it has no practical value in industry. The anatase is stable at room temperature, but it will transform into rutile at high temperature. Its transformation intensity depends on the manufacturing method and whether inhibitors or promoters are added during the calcination process.
Titanium dioxide (or titanium dioxide) is widely used in various structural surface coatings, paper coatings and fillers, plastics and elastomers. Other uses include ceramics, glass, catalysts, coated fabrics, printing inks, roofing granules and fluxes. According to statistics, the global demand for titanium dioxide reached 4.6 million tons in 2006, of which the coating industry accounted for 58%, the plastic industry accounted for 23%, the paper industry accounted for 10%, and others accounted for 9%. Titanium dioxide can be produced from ilmenite, rutile, or titanium slag. There are two production processes for titanium dioxide: sulfate process and chloride process. The sulfate process is simpler than the chloride process and can use low-grade and relatively cheap minerals. Today, about 47% of the world's production capacity uses the sulfate process, and 53% of the production capacity uses the chloride process.
Titanium dioxide is considered to be the best white pigment in the world and is widely used in coatings, plastics, papermaking, printing inks, chemical fibers, rubber, cosmetics and other industries.
Titanium dioxide (titanium dioxide) has stable chemical properties and does not react with most substances under normal circumstances. In nature, titanium dioxide has three types of crystals: brookite, anatase and rutile. The brookite type is an unstable crystal form with no industrial utilization value. The anatase type (A-type) and the rutile type (R-type) both have stable lattices and are important white pigments and porcelain glazes. Compared with other white pigments, they have superior whiteness, tinting power, hiding power, weather resistance, heat resistance, and chemical stability, especially non-toxicity.
Titanium dioxide is widely used in coatings, plastics, rubber, ink, paper, chemical fibers, ceramics, daily chemicals, medicine, food and other industries.
Dolomite is used in various industries
The chemical formula of dolomite is [CaMg(CO3)2], also known as dolomite limestone. Dolomite accounts for about 2% of the earth's crust. Dolomite sediments are common all over the world, mainly sedimentary rocks or equivalents of changed structures.
Dolomite is one of the widely distributed minerals in sedimentary rocks and can form thick dolomite. Primary sedimentary dolomite is directly formed in sea lakes with high salinity. A large amount of dolomite is secondary, formed by limestone being replaced by magnesium-containing solutions. Marine sedimentary dolomite is often interbedded with siderite layers and limestone layers. In lake sediments, dolomite coexists with gypsum, anhydrite, rock salt, potassium salt, etc.
Application of dolomite in various fields:
Metallurgical industry
Magnesium has good thermal conductivity and electrical conductivity. It is a non-magnetic and non-toxic metal. Magnesium alloys are light, durable, high-strength, high-toughness, and good mechanical properties. They are widely used in aviation, automobiles, precision castings, defense industry, and other industries. In the magnesium smelting industry. Dolomite is one of the important raw materials for the production of magnesium metal. The domestic silicothermic method is generally used to refine magnesium metal. The output accounts for about 20% and about 67% of the total amount of magnesium metal. The silicothermic method is to calcine and decompose dolomite to obtain a mixture of MgO and CaO. After the calcined powder is ground and sieved, it is mixed according to the molar ratio of Mg to Si of 2:1, and an appropriate amount of fluorite is added as a catalyst. The mixed lumps are made into balls and reduced with silicon at 1150-1200C to generate calcium silicate and magnesium. Dolomite is an important auxiliary material for steelmaking and sintering in the metallurgical industry.
Building materials industry
As the raw material of magnesium cementitious materials: dolomite is calcined at a certain temperature. Dolomite is partially decomposed to generate magnesium oxide and calcium carbonate, and then magnesium oxide solution and aggregate are added to stir and form, and high-strength ferro-ammonia cement materials are generated after curing. Ferro-ammonia cementitious materials are mostly used in the production of large packaging boxes and the 8th generation of Suifeng Street. They have broad application prospects in the development of new construction structures. Dolomite accounts for about 15% of the float glass mixture.
Chemical Industry
In the chemical industry, marbling is mainly used to produce magnesium compounds, which is also the best way to increase the added value of marbling products. The main industrialized chemical products are magnesium oxide, light magnesium carbonate, magnesium hydroxide, and various magnesium salt products. Light magnesium carbonate is also called industrial hydrated basic magnesium carbonate or basic magnesium carbonate. The molecular formula can be expressed as xMgCO3 yMg(OH)2 zHO. White monoclinic crystal or amorphous powder, non-toxic, odorless, relative density 2.16, stable in air. Slightly soluble in water, the aqueous solution is weakly alkaline. Easily soluble in acid and ammonium salt solution, reacts with acid to generate magnesium salt and releases carbon dioxide. High temperature pyrolysis turns into magnesium oxide.
Other applications
In agriculture, dolomite can neutralize acidic substances in the soil and be used for soil improvement. At the same time, the magnesium contained in dolomite can be used as magnesium fertilizer to supplement the magnesium in crops: dolomite is added to feed as a feed additive to increase the calcium and magnesium intake of poultry and livestock and enhance the nutrition of poultry and livestock.
In the field of environmental protection, after hydration and digestion of calcined dolomite powder, it mainly contains magnesium hydroxide and calcium hydroxide, which can absorb gases such as carbon dioxide and sulfur dioxide in flue gas. Therefore, calcined dolomite powder can be used for flue gas carbon dioxide separation (ECRS); dolomite can also be used in gasification furnaces to remove H2S from flue gas: using the high surface energy and adsorption of calcium hydroxide and magnesium hydroxide generated by hydration of active magnesium oxide in calcined dolomite powder, calcined dolomite can be used as a filter material for domestic water treatment, and can also be used to remove metal ions such as iron and manganese in industrial wastewater.
Varieties and applications of fine alumina
Fine alumina has many varieties and is widely used. It is the preferred material in many fields.
Therefore, "wide source of raw materials", "can be found everywhere", "cheap price" and "simple preparation" have become labels for alumina. Scarcity makes things valuable. These labels can easily lead people to misunderstand that alumina is a low-end material. First of all, the editor believes that these labels cannot determine whether alumina is low-end or not, but they can show that alumina is a very cost-effective material in many fields. Secondly, even from the perspective of price, technical content, performance and other aspects, alumina is not lacking in "high-end products". These "high-end products" play an irreplaceable role in high-precision fields such as semiconductors and aerospace.
Alumina fiber
The main component of alumina fiber is alumina (Al2O3), and the auxiliary components are SiO2, B2O3, MgO, etc. It is a high-performance inorganic fiber and a polycrystalline ceramic fiber with various forms such as long fiber, short fiber, and whisker. It has excellent properties such as high strength, high modulus, and corrosion resistance.
The application field of Al2O3 fiber is relatively wide. Al2O3 short fiber can be compounded with resin, metal or ceramic to prepare high-performance composite materials, and manufacture industrial high-temperature furnaces such as heating furnaces, kiln linings and electronic component calcining furnaces; Al2O3 continuous fiber reinforced composite materials have excellent properties such as high strength, high modulus and high stiffness. Its matrix is not easy to oxidize and fail during use. It also has excellent creep resistance and will not cause grain growth at high temperatures to cause the performance of the fiber to decrease. It is internationally recognized as a new generation of main materials for high-temperature resistant hot end components and has huge development potential; in addition to the above properties, functional Al2O3 nanofibers also have excellent properties such as low thermal conductivity, electrical insulation and high specific surface area. They are widely used in reinforced composite materials, high-temperature thermal insulation materials, catalytic filtration materials, etc.
High-purity alumina
High-purity alumina (4N and above) has the advantages of high purity, high hardness, high strength, high temperature resistance, wear resistance, good insulation, stable chemical properties, moderate high-temperature shrinkage performance, good sintering performance and optical, electrical, magnetic, thermal and mechanical properties that ordinary alumina powder cannot match. It is one of the high-end materials with the highest added value and the widest application in modern chemical industry.
At present, high-end high-purity alumina is mainly used for lithium battery electrode additives, solid-state battery electrolyte fillers, and wafer grinding and polishing in the semiconductor industry.
Spherical alumina
The morphology of alumina powder particles will directly affect its application performance in many fields. Compared with the common irregular, fibrous or flaky alumina powder particles, spherical alumina has a regular morphology, higher packing density, smaller specific surface area and better fluidity. It is widely used as thermal conductive filling material, polishing material, catalyst carrier, surface coating material, etc.
In industrial production, what are the classifications of barium sulfate?
Barium sulfate, for most people, the chemistry is not very well understood, in their eyes, barium sulfate is a dangerous chemical. In fact, in our daily life, barium sulfate can be said to be everywhere, but they usually appear in our lives in the form of manufactured products.
For example, most plastic products in our homes, air conditioners, some plastic accessories in cars, plastic bags used in supermarkets, etc., paints and coatings used in life, glass, etc. may contain barium sulfate.
In the physics and chemistry textbooks, the chemical formula of barium sulfate is BaSO4, which is generally a white rhombus, colorless and odorless, with a density of 4.499 and a melting point of up to 1580℃. Its chemical properties are very stable, insoluble in water, acid-resistant, alkali-resistant, non-toxic, non-magnetic, and can also absorb X-rays and gamma rays. In nature, barium sulfate is also called barite, a natural ore, generally in the shape of a forked crystal block, and its color is mainly determined by the type and amount of impurities it contains. Pure barite is colorless and transparent. Barite has no direct harm to the human body and can be directly contacted.
In industry, there are many classifications of barium sulfate, and the common ones are as follows:
1. Heavy barium, also known as barite powder or natural barium powder. It is made by people selecting natural barium sulfate ore (baryte) and then washing, grinding, drying and other processes. It has many impurities and its quality is mainly determined by the ore itself, but its price is low. It is usually used as a filler in the production of white pigments or low-grade coatings, plastics, and ink industries. It plays a role in reducing costs and improving gloss.
2. Precipitated barium sulfate, also known as industrial barium sulfate or precipitated barium. It is made by artificial processing. Unlike heavy barium, precipitated barium contains almost no impurities. It is slightly soluble in water and insoluble in acid. It is non-toxic in itself, but if it contains soluble barium, it can cause poisoning. Precipitated barium sulfate in industry is mainly generated by the reaction of barium sulfate with sulfuric acid, the reaction of barium chloride with sulfuric acid or sodium sulfate, and the reaction of barium sulfide with sodium sulfate. Precipitated barium sulfate is used as a filler in the fields of medicine, medium and high-end coatings and inks, plastics, rubber, glass, ceramics, etc. due to its stability and different specific indicators. People usually divide it into coating-grade precipitated barium sulfate, plastic-grade precipitated barium sulfate, etc. according to different applications. Its price is higher than that of heavy barium.
3. Modified barium sulfate, which is divided into modified barium sulfate and modified precipitated barium sulfate, is to enhance the performance of barite powder or precipitated barium sulfate in a certain aspect through relevant treatment. The application is similar to precipitation, and it mainly depends on its relevant properties. Among them, the one that has been further processed and refined is also called modified ultrafine barium sulfate or modified ultrafine precipitated barium sulfate. The price is higher than precipitated barium sulfate.
4. Nano-grade precipitated barium sulfate is to control its D50 (median particle size distribution) between 0.2μm-0.4μm through deep processing of modified precipitated barium sulfate. Nano-grade precipitated barium sulfate is mainly used in high-end paints, coatings and other industries.
10 major application areas of silicon micropowder
Silica powder is a kind of inorganic non-metallic material with wide applications. Silica powder is a micron-level powder obtained by crushing and pulverizing high-purity quartz ore by physical or chemical methods. Its particle size is generally between 1-100 microns, and the commonly used particle size is about 5 microns. With the advancement of semiconductor manufacturing processes, silica powder below 1 micron has gradually been widely used.
Silica powder has a series of advantages such as excellent dielectric properties, low thermal expansion coefficient, high thermal conductivity, high chemical stability, high temperature resistance, and high hardness. It can be widely used in copper clad laminates, epoxy molding compounds, electrical insulation materials, and adhesives. In addition, it can also be used in coatings, rubber, plastics, cosmetics, and honeycomb ceramics.
1 Copper clad laminate
Adding silicon powder to copper clad laminate for electronic circuits can improve the linear expansion coefficient and thermal conductivity of printed circuit boards, thereby effectively improving the reliability and heat dissipation of electronic products.
2 Epoxy molding compound (EMC)
Filling silicon powder into epoxy molding compound for chip packaging can significantly improve the hardness of epoxy resin, increase thermal conductivity, reduce the exothermic peak temperature of epoxy resin curing reaction, reduce linear expansion coefficient and curing shrinkage, reduce internal stress, and improve the mechanical strength of epoxy molding compound, making it infinitely close to the linear expansion coefficient of the chip.
3 Electrical insulation materials
Silicon powder is used as epoxy resin insulation filler for electrical insulation products. It can effectively reduce the linear expansion coefficient of the cured product and the shrinkage rate during the curing process, reduce internal stress, and improve the mechanical strength of the insulating material, thereby effectively improving and enhancing the mechanical and electrical properties of the insulating material.
4 Adhesives
Silicon powder, as an inorganic functional filling material, is filled in adhesive resin, which can effectively reduce the linear expansion coefficient of the cured product and the shrinkage rate during curing, improve the mechanical strength of the adhesive, and improve the heat resistance, anti-permeability and heat dissipation performance, thereby improving the bonding and sealing effect.
5 Plastics
Silicon powder can be used in plastics in products such as polyvinyl chloride (PVC) flooring, polyethylene and polypropylene films, and electrical insulation materials.
6 Coatings
In the coatings industry, the particle size, whiteness, hardness, suspension, dispersibility, low oil absorption, high resistivity and other characteristics of silicon micropowder can improve the corrosion resistance, wear resistance, insulation and high temperature resistance of the coating. Silicon micropowder used in coatings has always played an important role in coating fillers due to its good stability.
Spherical silica powder has good fluidity and large specific surface area, which makes it suitable for cosmetics such as lipstick, powder, foundation cream, etc. In powder products such as powder, it can improve fluidity and storage stability, thereby playing a role in preventing caking; the smaller average particle size determines its good smoothness and fluidity; the larger specific surface area makes it have better adsorption, can absorb sweat, fragrance, nutrients, and make cosmetic formulas more economical; the spherical shape of the powder has good affinity and touch to the skin.
8 Honeycomb ceramics
Automobile exhaust filter DPF made of honeycomb ceramic carrier for automobile exhaust purification and cordierite material for diesel engine exhaust purification is made of alumina, silica powder and other materials through mixing, extrusion molding, drying, sintering and other processing.
9 Rubber
Silicon powder is a reinforcing material for rubber. It can enhance the comprehensive properties of rubber, such as strength, toughness, elongation, wear resistance, finish, anti-aging, heat resistance, anti-slip, tear resistance, acid and alkali resistance, etc. It is indispensable in the production process of rubber products.
10 Artificial quartz
Silicon powder is used as a filler in artificial quartz board, which can not only reduce the consumption of unsaturated resin, but also improve the wear resistance, acid and alkali resistance, mechanical strength and other properties of artificial quartz board. The filling ratio of silicon powder in artificial marble is generally about 30%.
Key raw material for solid electrolytes—Zirconia
ZrO2 is an oxide material with high temperature resistance, high hardness and good chemical stability. It has high melting point and boiling point, so it can maintain stable physical and chemical properties in high temperature environment. In addition, ZrO2 also has a low thermal expansion coefficient and good electrical insulation properties. This makes it one of the preferred raw materials for LLZO solid electrolyte.
High hardness: The hardness of ZrO2 is second only to diamond, and it has high wear resistance.
High melting point: The melting point of ZrO2 is very high (2715℃). The high melting point and chemical inertness make ZrO2 a good refractory material.
Excellent chemical stability: ZrO2 has good resistance to chemicals such as acids and alkalis and is not easily corroded.
Good thermal stability: ZrO2 can still maintain good mechanical properties and chemical stability at high temperatures.
Relatively large strength and toughness: ZrO2, as a ceramic material, has a large strength (up to 1500MPa). Although the toughness is far behind some metals, compared with other ceramic materials, zirconium oxide has a higher fracture toughness and can resist external impact and stress to a certain extent.
There are various preparation processes for ZrO2, including pyrolysis, sol-gel, vapor deposition, etc. Among them, pyrolysis is one of the most commonly used preparation methods. This method reacts zircon and other raw materials with alkali metal or alkaline earth metal oxides at high temperature to generate zirconate, and then obtains ZrO2 powder through acid washing, filtration, drying and other steps. In addition, the performance of ZrO2 can be regulated by doping different elements to meet the needs of different solid-state batteries.
The application of ZrO2 in solid-state batteries is mainly reflected in oxide solid electrolytes, such as lithium lanthanum zirconium oxide (LLZO) and lithium lanthanum zirconium titanium oxide (LLZTO), which exist in garnet-type crystal structures. In these solid electrolytes, ZrO2 occupies a very important proportion. For example, in the mass of LLZO before sintering, ZrO2 accounts for about 25%. In addition, in order to reduce the interface resistance in solid-state batteries and improve the efficiency of lithium ion migration, the positive and negative electrode materials usually need to be coated with materials such as LLZO. At the same time, oxide semi-solid batteries also need to construct a layer of ceramic diaphragm composed of materials such as LLZO, which further increases the amount of ZrO2 used in solid-state batteries.
With the continuous development of solid-state battery technology and the expansion of its application fields, the demand for ZrO2 as a solid electrolyte raw material will continue to grow. In the future, ZrO2 is expected to play a more important role in the field of solid-state batteries by further optimizing the preparation process, regulating performance and reducing costs. At the same time, with the continuous emergence of new solid-state electrolyte materials, ZrO2 will also face more intense competition and challenges. However, with its unique properties and broad application prospects, ZrO2 will still have an irreplaceable position in the field of solid-state batteries.
Inventory of 20 kinds of inorganic powders for plastics
Plastics are important products for production and daily life in today's society. The use of inorganic powders can effectively improve the physical and chemical properties of plastic products and enhance the performance of plastic products.
Wollastonite
Wollastonite is a natural calcium silicate (CaSiO3) with a light white needle-like structure. The aspect ratio (L/D) of processed wollastonite can reach more than 15/1. It is a fibrous inorganic reinforcing filler in plastics.
Talc
Talc has a flaky structure and has a significant reinforcing and modifying effect in plastics and rubber. It can improve the tensile strength, impact performance, creep resistance, heat resistance, tear resistance, etc. of plastic products.
Barium sulfate
The natural ore (barite) is crushed, washed and dried to obtain barite powder (also called heavy barium sulfate). Barium sulfate has excellent properties such as chemical stability, scratch resistance, heat resistance, high refractive index, outstanding sound insulation, heat preservation, and high gloss.
Mica
Mica is a layered aluminum silicate mineral with a unique structure. In addition to its reinforcing effect, it can also improve the air tightness, optical properties, and insulation properties of plastics.
Glass beads
Glass beads have the advantages of high temperature resistance and low thermal conductivity. When used to fill plastics, they can not only increase the wear resistance, pressure resistance, and flame retardancy of the material, but also its special spherical surface can improve the processing fluidity of the material; in addition, it has good surface gloss, which can increase the surface gloss of the product and reduce the adsorption of dirt on the surface.
Magnesium hydroxide
The chemical formula of magnesium hydroxide is Mg(OH)2. It can be prepared by chemical methods or obtained by crushing brucite ore. Magnesium hydroxide has a flame retardant effect. After surface modification, it can be filled into plastics to achieve the effect of smoke suppression.
Aluminum hydroxide
Aluminum hydroxide is a compound with the chemical formula Al(OH)x. It is used as a flame retardant, smoke suppressant and filler in PVC. Since it reduces the mechanical strength of thermoplastics when used in them, it is mostly used in thermosetting plastics.
Zeolite
Zeolite is a framework-shaped, hydrated alkali or alkaline earth metal aluminum silicate mineral. Its specific gravity, nanoporous structure, adsorption and chemical resistance can provide new development space for expanding the application of plastic products.
Kaolin
When used for filling and modification of plastics, it can improve the insulation strength of plastics. Without significantly reducing the elongation and impact strength, it can improve the tensile strength and modulus of thermoplastics with low glass transition temperatures. It can act as a nucleating agent for polypropylene, which is beneficial to improving the rigidity and strength of polypropylene. It has a significant infrared barrier effect.
Glass fiber (GF)
Glass fiber has high mechanical strength, elastic modulus, heat resistance and insulation, and is usually used to reinforce composite materials. GF can effectively make up for the shortcomings of biodegradable plastics, and can also significantly reduce the cost of products and expand the application range of biodegradable plastics.
Montmorillonite
Montmorillonite is a hydrophilic layered silicate material. Because of its nanometer size, it has a nano effect and can effectively improve the performance of polymers. Especially after modification, its application range is wider.
Other inorganic powders
Nano silicon dioxide has relatively stable chemical properties and a large specific surface area, which can effectively improve the strength, wear resistance and aging resistance of resin-based materials.
Rutile titanium dioxide can increase the reflectivity of light as a plastic filler and play the role of a light shielding agent.
Fly ash has the advantages of small specific gravity, high hardness and good fluidity.
Carbon black is generally used in the plastic industry for coloring, UV protection or conductivity.
Black inorganic minerals such as black talc and black calcite can partially replace carbon black. While fully utilizing mineral resources, the production cost has obvious advantages.
Using bentonite as an additive for degradable materials can replace starch and other chemical additives to reduce costs.
Halloysite has unique tubular nanostructures and good water dispersibility, different properties of inner and outer walls, high adsorption, biocompatibility and other unique and excellent physical and chemical properties.
Molybdenum disulfide is an inorganic compound composed of molybdenum and sulfur, and its chemical formula is MoS2.