Manganese orthosphate is a chemical compound, known as manganese phosphate, is chemically classified as an inorganic colorant. This pigment is widely used in various industrial and cosmetic applications due to its distinctive color and excellent stability.
Chemical Name
manganese(2+);phosphate
Chemical Composition and Structure
Manganese orthosphate is an inorganic compound with the chemical formula Mn3(PO4)2. It consists of manganese (Mn2+) and phosphate (PO4) ions. This composition gives the pigment its characteristic color.
Physical Properties
This pigment typically appears as a fine powder with color ranging from white to gray. It has high density and excellent covering power. Manganese orthosphate is known for its chemical stability, resistance to light and heat, and inert nature, making it suitable for long-lasting applications. Its opacity and tinting strength make it a versatile pigment for various uses.
Chemical Industrial Synthesis Process
- Preparation of reagents. The main raw materials include manganese(II) sulfate (MnSO₄) and sodium phosphate (Na₃PO₄) or ammonium phosphate ((NH₄)₃PO₄).
- Preparation of manganese sulfate solution. The manganese sulfate is dissolved in deionized water to form a manganese sulfate solution.
- Addition of phosphate. Sodium phosphate or ammonium phosphate is slowly added to the manganese sulfate solution with constant stirring. This reaction forms a precipitate of manganese(II) phosphate.
- Formation of the precipitate. The solution is heated to about 90-100°C to promote the complete formation of the precipitate.
- Filtration. The resulting suspension is filtered to separate the solid precipitate from the aqueous solution.
- Washing. The precipitate is washed with deionized water to remove any soluble impurities.
- Drying. The washed precipitate is dried at controlled temperatures to remove residual moisture and obtain a dry powder.
- Calcination. The dried precipitate is calcined at a temperature of about 400-600°C to obtain the stable form of manganese(II) phosphate.
- Grinding. The calcined product is ground to obtain a fine and uniform powder.
- Classification. The calcined powder is classified to ensure a uniform particle size. This step may involve sieving or the use of air classifiers.
- Stabilization. The Manganese orthosphate powder is stabilized to ensure its stability during transportation and storage, preventing aggregation and degradation.
- Quality control. The Manganese orthosphate undergoes rigorous quality testing to ensure it meets standards for purity, color intensity, and safety. These tests include chemical analysis, spectroscopy, and physical tests to determine particle size and rheological properties.
What it is used for and where
Cosmetics
Restricted cosmetic ingredient as IV/141 a Relevant Item in the Annexes of the European Cosmetics Regulation 1223/2009. Substance or ingredient reported:
- Trimanganese bis(orthophosphate)
Cosmetics - INCI Functions
- Colorant. This ingredient has the function of colouring the solution in which it is inserted in a temporary, semi-permanent or permanent manner, either alone or in the presence of the complementary components added for colouring.
Manganese orthosphate is used in cosmetic products such as eyeshadows, blushes, and face powders due to its high opacity and ability to provide a uniform finish.
Industrial Applications
Paints and Coatings: In the paint industry, manganese phosphate is used to achieve specific color tones and enhance UV resistance. Its stability and tinting properties make it ideal for decorative and protective coatings.
Plastics and Polymers: This pigment is employed in the production of plastics and polymers to improve color uniformity and opacity. It is commonly used in products such as packaging materials and consumer goods.
Ceramics and Glass: Manganese orthosphate is used in the production of ceramics and glass to achieve stable colors. It is particularly valued for its resistance to high-temperature processes.
Inks: The pigment is also used in printing inks to produce intense colors, ensuring high-quality and durable prints.
Safety
Manganese orthosphate is generally considered safe for use in consumer products when handled according to proper safety procedures. It is important to avoid inhalation of the powder and minimize direct contact with skin and eyes.
Molecular Formula Mn3(PO4)2
Molecular Weight 149.909 g/mol
CAS 10124-54-6 14154-09-7
EC number 233-341-0 237-997-9
UNII
DTXSID101010075
Synonyms:
CI 77745
Manganous phosphate
Manganese orthophosphate 
Ammonium phosphate 
