Azo dyes constitute the largest class of synthetic colorants, renowned for their versatility, vibrant colors, and cost-effectiveness. Among these, Allura Red AC, identified by CAS 25956-17-6, is a prominent synthetic red azo dye widely used across industries like food, pharmaceuticals, and cosmetics. Understanding its fundamental chemical properties is crucial for B2B professionals involved in procurement, formulation, and manufacturing.

The Chemistry of Allura Red AC
Allura Red AC is a monoazo dye, characterized by the presence of one azo group (-N=N-) linking two aromatic systems. Its chemical name is disodium 6-hydroxy-5-[(2-methoxy-5-methyl-4-sulfonato-phenylazo)-2-naphthalene-sulfonate]. The structure features sulfonate groups, which render it water-soluble, and methoxy and methyl substituents that influence its color and stability. The molecule's complex structure, with its conjugated system of double bonds, is responsible for its intense absorption of visible light, resulting in its characteristic deep red color.

Synthesis and Manufacturing Processes
The synthesis of Allura Red AC typically involves a diazotization reaction followed by an azo coupling reaction. A common method starts with the diazotization of cresidinesulfonic acid, which is then coupled with 2-naphthol-6-sulfonic acid. This chemical pathway is well-established, allowing for large-scale industrial production. For businesses looking to buy Allura Red AC dye, understanding that it is a synthetically produced compound from chemical precursors is important. The efficiency and control of these synthesis steps by a manufacturer directly impact the final product's purity and consistency. Exploring options from a reliable Allura Red AC manufacturer in China often provides access to optimized production facilities and economies of scale.

Key Chemical Properties and Specifications
Key specifications for Allura Red AC include its appearance (typically a dark red powder or granules), molecular formula (C18H14N2Na2O8S2), and molecular weight (approximately 496.42 g/mol). A critical parameter for industrial users is its assay, which indicates the concentration of the active dye compound, usually specified as ≥85.0%. Other important properties include solubility, melting point (often decomposing rather than melting at high temperatures, typically >300 °C), and stability under various conditions (pH, light, heat). These properties dictate its suitability for different applications. For instance, its water solubility makes it ideal for aqueous systems, but its stability in acidic or alkaline environments needs to be considered during formulation. Knowing these specifications helps procurement specialists to confidently source FD&C Red No. 40 that will perform optimally.

Industrial Significance and Sourcing Considerations
The widespread use of Allura Red AC stems from its good color strength, stability, and relatively low cost compared to some natural alternatives. For B2B buyers, understanding the technical data sheet (TDS) and the supplier's quality control protocols is paramount. When inquiring about Allura Red AC price, it's important to compare specifications and supplier reliability. A consistent supply chain and adherence to quality standards are key considerations when choosing a supplier of Allura Red AC, ensuring that your production processes are not disrupted by ingredient variability or availability issues.