Industrial grade 99% Iron oxide CAS 1332-37-2

What is iron oxide brown? What are its industrial applications?

1. What is iron oxide brown?

Iron oxide brown, also known as iron brown or brown iron oxide, is a brown inorganic pigment made by blending iron oxide red (Fe2O3), iron oxide yellow (FeOOH), and iron oxide black (Fe3O4) in different proportions. It is one of the most widely used iron oxide pigments, and its composition can be described as follows:

Fe2O3·FeO (a mixture of iron oxides, CAS No.: 52357-70-7; synthetic iron brown is a mixture of iron red, iron yellow and iron black)

It is a brownish-red powder at room temperature, non-toxic and odorless, with high coloring and hiding power, stable chemical properties, and resistance to light, alkali, heat, and weathering. It can absorb almost all ultraviolet wavelengths, thus exhibiting excellent resistance to ultraviolet aging. Natural iron brown often contains dopants such as carbon and manganese oxide, while synthetic iron brown is a blend of iron black, iron red, and iron yellow, with pure color, stable quality, and good reproducibility.

Structurally, iron oxide brown inherits the characteristics of three iron oxide pigments: iron red (red hue), iron yellow (yellow hue), and iron black (black hue). It has a wide color range, and various brown shades from light brown and reddish brown to dark brown can be obtained by adjusting the proportion of the three components. Its hiding power and tinting strength are superior to those of single iron oxide pigments.

Chemically, iron oxide brown is a stable inorganic pigment, which has good acid and alkali resistance. It is not soluble in water and organic solvents, does not migrate or bleed and is compatible with cement, coatings, plastics and other base materials. It is widely used in colouring applications where weather resistance and lightfastness are required. It should be kept in a dry place, inside a sealed container.

Industrial Grade Iron Oxide Brown is used for colouring in industrial applications such as coatings, plastics and rubber, and building materials. Common specifications in terms of iron content and fineness. Industrial-grade products are focused on the following metrics:

1.Tinting power and covering power

The colouring effect and dosage of pigments are governed by tinting strength and hiding power, which are the key indicators of pigment performance and directly affect the formulation cost.

2. Screen residue (325 mesh)

The residue on the sieve is an indicator of the fineness and dispersibility of the pigment and must be controlled within an extremely low range to ensure uniform colouring without particles.

3.Moisture

Pigment moisture content affects the storage stability and the dispersibility of pigments and must be carefully controlled.

4.Water-soluble content

Water-soluble substances are the soluble salt impurities which affect the stability of pigments in cement and coating systems and should be controlled in reasonable range.

5. Oil Absorption

The amount of oil absorbed affects the amount of oil used in coating and ink formulations and batch stability has to be maintained to ensure repeatability of formulation.

6.pH Value

The pH value influences the compatibility of pigments with cement and paint base materials and shall be controlled within the indicated range.

What are the applications of industrial-grade iron oxide brown?

High tinting strength, high hiding power, light and weather resistance are the unique features of industrial grade iron oxide brown, used in building materials, coatings, plastics, rubber, ceramics, paper making, inks, leather and other fields. All applications are provided below (no omissions):

1.Building material coloring pigments (core applications in the building materials industry)

Iron oxide brown is used to colour coloured cement, coloured cement tiles, coloured cement bricks, imitation glazed tiles, concrete tiles, coloured mortar, coloured asphalt, terrazzo, mosaic tiles and artificial marble which helps building materials get a weather resistant and durable brown hue. It is the most commonly used application of iron oxide pigments in the building materials industry.

2.Pigments for coatings (coating industry)

Iron oxide brown is a colouring pigment used in wall coatings for indoor and outdoor use, anti-rust paints, coloured paints and wood coatings. It helps the coatings to obtain stable brown colour, and improves the service life of coating film with excellent light and weather resistance. It is widely used in architectural and industrial coatings.

3.Plastic coloring pigments (plastics industry)

Iron oxide brown is used as a colouring pigment in plastic masterbatches and plastic products, and helps plastic products get a uniform and stable brown hue. It is widely used in injection moulding, extrusion and blow moulding products due to its non-migrating, non-bleeding and heat-resistance properties.

4. Rubber coloring pigments (rubber industry sector)

Iron oxide brown is used as a colouring pigment for rubber products to give rubber a weather resistant brown colour. It is used extensively in products such as tires, shoe soles, seals and rubber flooring.

5.Ceramic glaze colouring pigments (ceramic industry)

Iron oxide brown is a colour pigment used in ceramic glazes, coloured glazes and building ceramics. It makes it possible to obtain a stable brown glaze surface of ceramic products. It has wide application in ceramic tiles, sanitary ware and daily-use ceramics.

6.Pigments for paper colouring (Paper industry)

Iron oxide brown is used for paper and paperboard as a colour pigment and gives paper products a brown colour. It is used in the speciality paper and packaging paper industries.

7. Ink colourants (ink printing industry)

Iron oxide brown is used as a colourant in printing inks to give inks a lightfast brown colour and is widely used in packaging printing and speciality printing.

8. Leather industry - Leather dye pigments

Iron oxide brown is used as a pigment for leather finishing and colouring, to give leather a natural brown colour. Iron oxide brown is widely used for leather bags, shoes and leather goods.

9. Colouring of wood-plastic composites and wood coatings (wood processing industry)

Iron oxide brown is used to impart a weather resistant brown hue to wood products such as wood flooring, wood-plastic composites (WPC) and wood coatings. It is very common in wood flooring, outdoor wood-plastic composites and furniture.

10.Coloring of paving and decorative materials (ground paving field)

Iron oxide brown is used for coloring pavers, sidewalk bricks, and decorative flooring materials, helping outdoor surfaces achieve a weather-resistant and durable brown earth tone. It is an important coloring pigment in the field of floor paving.

11.Applications of magnetic materials (electronics industry, containing iron black component)

The iron black (Fe3O4) component in iron oxide brown is magnetic, and the related iron oxides can be used as magnetic raw materials for applications such as soft magnetic ferrite cores in the electronics industry, serving the electronics industry such as communication equipment and electronic transformers.

Summarize

Iron oxide brown (Fe2O3·FeO, CAS No. 52357-70-7) is a brownish-red inorganic pigment composed of iron oxide red, iron oxide yellow, and iron oxide black. It is non-toxic, chemically stable, and resistant to light and weathering. Its high tinting strength and high hiding power make it one of the most widely used iron oxide pigments. In daily life, we encounter it through colored floor tiles, wall paints, plastic and rubber products, ceramic sanitary ware, wood-plastic composite flooring, leather products, and printed materials. In industry, iron oxide brown is widely used in coloring building materials, paints, plastics, rubber, ceramic glazes, papermaking, inks, leather coloring, wood coatings and wood-plastic composites, paving and decorative materials, and magnetic materials. It is a versatile brown pigment bridging "iron oxide pigment chemistry" with "building materials, paints, plastics, rubber, ceramics, leather, and electronics."