Iron oxide, is an inorganic compound, chemical formula Fe2O3, is a reddish-brown powder, insoluble in water, mainly used as an inorganic pigment, for paint, rubber, plastics, building coloring, can also be used as magnetic materials, food red pigment, analytical reagents, catalysts and polishing agents.

As a pigment, iron oxide is widely used in high-grade automotive coatings, architectural coatings, anti-corrosion coatings, powder coatings, is a better environmental protection coating, the annual consumption of iron oxide pigments in the world exceeds 1 million t, second only to titanium dioxide, ranking second to inorganic pigments. In 2021, China's iron oxide production was 568,600 tons, an increase of 5.3%, and in the first half of 2022, iron oxide production reached 293,200 tons.

In recent years, China's iron oxide domestic market in the economic downward pressure, environmental protection policies continue to upgrade, paint terminal downstream real estate industry downturn under the influence of the demand continues to decline, resulting in China's iron oxide industry market size continued to decline. In 2021, due to the large rise in global raw material prices, the size of the iron oxide market has rebounded. In 2021, the market size of China's iron oxide industry is about 2.2 billion yuan, an increase of 54.3%, and the market size is expected to reach 2.7 billion yuan in 2023.

Iron oxide as a pigment is widely used in high-grade automotive coatings, architectural coatings, anti-corrosion coatings, powder coatings, is a better environmental protection coating, all. The annual consumption of iron oxide pigments in the world exceeds 1 million t, second only to titanium dioxide, ranking second to inorganic pigments. The use of iron oxide as a pigment not only maintains the advantages of good heat resistance, weather resistance and ultraviolet absorption of general inorganic pigments, but also can be well dispersed in oil-based carriers, and the paint or ink modulated with it has satisfactory transparency. The use of iron oxide with semiconductor characteristics to make coatings, because of its high conductive characteristics, can play a role in electrostatic shielding.

Iron oxide is a common coloring agent used in glass production. Iron oxide colored glass can absorb both ultraviolet and infrared rays, so it is widely used in the manufacture of heat-absorbing glass, sunglasses glass, industrial protective glasses glass and military. Use infrared resistant paint. At the same time, it has the function of low price, absorption hot wire and ultraviolet light.

In addition, iron oxide pigments are also widely used abroad as colorants and protective agents for wood coating. The use of transparent iron oxide pigments instead of traditional pigments can retain the clear grain of the wood, and its high light resistance makes the color of the furniture durable. The ultraviolet rays in the sun can decompose the wood lignin and destroy the cell structure, leading to the aging of wood, and the nano iron oxide pigment will not scatter light because of its small particles, uniform distribution, and absorb ultraviolet radiation, so it can play a role in protecting wood.

Iron oxide pigments are red, yellow, green, brown, orange and black. These colors contain many different hues. Therefore, according to different color needs, it is a very meaningful work to subdivide it by different application fields and industries.

It has developed from oil-based coatings to synthetic resin coatings, and all kinds of coatings are inseparable from the application of pigments, especially iron oxide pigments have become indispensable pigments in the paint industry. Iron oxide pigments used in coatings include iron yellow, iron red, iron brown, iron black, mica iron oxide, transparent iron yellow, transparent iron red, as well as translucent products, of which a large amount of wide range of iron red is the most important.

Iron red has good heat resistance, does not change color at 500C, does not change the chemical structure at 1200°C, and is extremely stable. It can absorb the ultraviolet spectrum of sunlight, so it has a protective effect on the coating, resistant to dilute acid, alkali, water and solvent, so that it has good weather resistance. When the granularity of iron red is 0.2μm, it has a yellow phase, the specific surface area and oil absorption are also large, and when the granularity increases, the hue moves from red phase to purple, and the specific surface area and oil absorption also become smaller.

Iron red is widely used in anti-rust coatings with physical anti-rust function, and the moisture in the atmosphere can not penetrate into the metal layer, and can increase the density and mechanical strength of the coating. The iron red water soluble salt applied to the anti-rust paint is low, which is conducive to improving the anti-rust performance, especially when the chloride ion increases, the water is easy to penetrate into the coating, and the corrosion of the metal is also accelerated.

Compared with natural products, the former has a larger density, small particle size, high purity, good hiding power, high oil absorption, and strong coloring power. In some coating formulas, natural iron red is shared with finished products, such as iron red alkyd primer for vehicles, machines, instruments and other black metal surfaces.

Iron yellow and iron red have good light resistance, solvent resistance, alkali resistance, dilute acid resistance and other characteristics, its heat resistance is slightly poor, in 135°C/ 1h and 177°C / 5min heat treatment, due to the gradual loss of crystal water and red phase transformation, so it can not be used in high drying temperature paint.

The synthetic iron yellow has high coloring power and bright color light, and can be produced according to the needs of various colors of iron yellow, and the abrasive property is also good, which has the effect of shielding ultraviolet radiation and can extend the application life of the coating. Due to its low price, iron yellow can be mixed with stable phthalocyanine blue, iron blue and other green, and iron red, iron black and other brown.

The application surface and quantity of iron yellow are less, and the use of smaller and more iron red, oil smoke and other pigments mixed with the application of paint should control the drying temperature to prevent the temperature is too high color turn red. In terms of latex paint coloring, a small amount of iron yellow color paste can be added to make it beige, and the light resistance is better than that of organic yellow fast yellow with single azo, and can also be mixed to obtain the brightness of organic yellow and the durability of iron yellow. Iron brown, iron black Natural iron brown often contains carbon, manganese oxide and other doping substances, the finished product is a mix of iron black, iron red and iron yellow, has a high coloring power and hiding power.

Article source: China Business Information Network, Shanghai Lianshuo Biotechnology Co., LTD., Mr. Zhang, love to play and love to make fun