Description
Pigment yellow 42, also known as Yellow Iron oxide is a yellow powder in the form of an alkaline oxide with comparatively stable chemical properties. It is is insoluble in water and alcohol, slightly soluble in acids but completely dissolves in concentrated hydrochloric acid. When heated to 80℃, it loses water and converts to red ferric oxide. It is used in coating, printing ink and paint, and also as a coloring agent for building material, rubber and paper-making. It is widely used due to its bright and pure colour, good weather proofing and high opacity. It is manufactured by the precipitation of ferric oxide hydroxide followed by purification through washing, drying and milling.
References
1.https://mistralhowto.wordpress.com/2012/03/12/what-is-pigment-yellow-42-and-what-is-it-used-for/
2.https://hazmap.nlm.nih.gov/category-details?id=20391&table=copytblagents
3.http://carriagehousepaper.com/pigment-yellow-42-iron-oxide-ochre-568
Chemical Properties
yellow powder(s) [STR93]
Uses
Antihyperparathyriod
Uses
Pigment Yellow 42 (Technical Grade) is used in the topical solar composition protecting skin exposed to irradiation of high energy visible light.
Flammability and Explosibility
Non flammable
Synthesis
74g of iron filings were added to 1000ml of 15% sulfuric acid and reacted until the iron filings disappeared, generating ferrous sulfate with a concentration of about 200g/L. To the ferrous sulfate solution produced above, enough 30% sodium hydroxide was added, stirring constantly to convert a total of 40% of the iron into ferrous hydroxide [Fe(OH)2], and air was passed through the solution at 30-35C to oxidize the Fe to Fe to form nuclei. Then add 90g / L of iron filings to which the treatment, so that the generation of 7g / L of the nucleus and 40g / L of ferrous sulfate, continue to heat to 85 , at a rate of 600L / h drum air oxidation for 64h, and then filtered, washed, dried, crushed to produce aqueous iron oxide yellow.
Properties and Applications
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TEST ITEMS
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SPECIFICATION
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APPEARANCE
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DARK YELLOW POWDER
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CONTENT OF
Fe
2
O
3
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86% min
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pH VALUE
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3-7
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SHADE
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CLOSE TO STANDARD
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OIL ABSORPTION
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25-35%
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RESIDUE ON 320 MESH
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0.3% max
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WATER SOLUBLE
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0.3% max
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VOLATITE 105 °C
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1.0% max
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TINTING STRENGTH
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98-102 %
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