Naphthalene, identified by CAS number 91-20-3, is a polycyclic aromatic hydrocarbon that has been a staple in the chemical industry for decades. It is most commonly recognized as a white crystalline solid, often appearing as flakes or a powder, possessing a characteristic strong aromatic odor. Its physical properties, such as a melting point of around 80-82°C and a boiling point near 218°C, are well-documented and critical for its handling and processing.

The significance of naphthalene stems from its versatility as a chemical intermediate. One of its primary roles is in the production of phthalic anhydride. This reaction is a cornerstone of the petrochemical industry, feeding into the manufacturing of plasticizers, resins, and coatings. The demand for these end products directly drives the need for a consistent and high-quality supply of naphthalene.

In the dye industry, naphthalene derivatives are indispensable. Through various chemical reactions, naphthalene is transformed into precursors for a vast array of dyes, including azo dyes and other complex colorants used in textiles, printing inks, and paints. The purity of the naphthalene used in these synthesis routes directly impacts the brilliance, fastness, and consistency of the final dye products.

The pharmaceutical sector also relies heavily on naphthalene as a building block for synthesizing various drug molecules. Its aromatic structure can be modified and functionalized to create active pharmaceutical ingredients (APIs) with specific therapeutic properties. For pharmaceutical applications, stringent purity standards are non-negotiable, ensuring the safety and efficacy of the final medicinal products.

Beyond these major applications, naphthalene finds its way into agrochemicals, acting as an intermediate for certain pesticides and insecticides. It also serves as a precursor for surfactants, which are vital in detergents, emulsifiers, and various industrial cleaning agents. Historically, it was widely known for its use in mothballs, though its industrial chemical applications are far more extensive and economically significant.

For manufacturers and researchers, understanding the purity specifications of refined naphthalene is crucial. Typically, industrial grades offer high purity, often exceeding 99%. This high purity is essential to minimize side reactions and ensure predictable outcomes in complex synthesis processes. Suppliers like NINGBO INNO PHARMCHEM CO.,LTD prioritize quality control to deliver naphthalene that consistently meets these exacting standards. Proper handling, including storage in cool, dry, well-ventilated areas and awareness of its flammability, is also a key aspect of its safe use.

In essence, refined naphthalene (CAS 91-20-3) is a fundamental chemical that underpins many critical industries. Its journey from coal tar to essential intermediate highlights its enduring value in chemical synthesis. NINGBO INNO PHARMCHEM CO.,LTD is proud to be a reliable provider of this vital compound, supporting the ongoing innovation and production across diverse industrial sectors.