Acid Blue 80 (CI 61585) is a chemical compound, a synthetic blue dye with an anthraquinone unit and is known as CI 61585.

Chemical name: 

Sodium 3,3'-(9,10-dioxoanthracene-1,4-diyldiimino)bis(2,4,6-trimethylbenzenesulphonate) 

Dyes that contain anthraquinone (an organic aromatic compound derived from anthracene) have as characteristic the brilliance of the color.

Chemical Industrial Synthesis Process

• Preparation of reagents. The main raw materials include phthalic anhydride, benzene, and concentrated sulfuric acid.
• Synthesis of anthraquinone intermediate. The production of CI 61585 begins with the condensation of phthalic anhydride with benzene in the presence of concentrated sulfuric acid, forming the anthraquinone intermediate.
• Substitution. The anthraquinone is further treated with specific reagents to introduce functional groups that impart the desired color. This may include sulfonation, nitration, or other substitution reactions.
• Oxidation. The functionalized structure undergoes an oxidation reaction to complete the formation of the anthraquinone chromophore, which is responsible for the coloring properties of CI 61585.
• Purification. The crude CI 61585 product is purified using techniques such as crystallization, filtration, and chromatography to remove impurities and achieve a high-purity colorant.
• Stabilization. The purified CI 61585 is stabilized to ensure its stability during transportation and storage, preventing degradation and oxidation.
• Quality control. The CI 61585 undergoes rigorous quality testing to ensure it meets standards for purity, color intensity, and safety. These tests include chemical analysis, spectroscopy, and microbiological testing.

What it is for and where

Cosmetics

It is a restricted ingredient as IV/93  a Relevant Item in the Annexes of the European Cosmetics Regulation 1223/2009. Ingredient or substance at risk:  Sodium 3,3'-(9,10-dioxoanthracene-1,4-diyldiimino)bis(2,4,6-trimethylbenzenesulphonate)

Safety 

It is an ingredient that has some important health-related contraindications: to be used only in cosmetic products that have contact with the skin for a short time.

• Molecular Formula   C₃₂H₂₈N₂Na₂O₈S₂
• Molecular Weight   678.7 g/mol
• CAS  4474-24-2
• UNII ET8107F56D
• EC Number 224-748-4
• DTXSID2041705

Synonyms:

• CI 61585
• Weak Acid Brilliant Blue RAW
• Alizarine Blue BL
• Acid Brilliant Blue Anthraquinone