For professionals in the chemical and materials industries, a deep understanding of a compound's properties is fundamental to its effective application. 2-Hydroxy-4-methoxybenzophenone, identified by CAS number 131-57-7 and often referred to as BP-3 or Oxybenzone, is a cornerstone UV absorber valued for its specific chemical and physical characteristics. As a leading manufacturer and supplier in China, we provide detailed insights into this versatile chemical.

Chemically, BP-3 has the molecular formula C14H12O3 and a molecular weight of 228.24 g/mol. Its structure, featuring a benzophenone backbone with hydroxyl and methoxy groups, is key to its UV absorption capabilities. These functional groups allow it to efficiently absorb radiation in the ultraviolet spectrum, particularly between 280 and 360 nm, by undergoing excited-state intramolecular proton transfer (ESIPT), a process that dissipates the absorbed energy as heat, thereby protecting the host material.

Physically, BP-3 typically presents as a pale yellow crystalline powder. Its melting point range is generally between 62-64°C, making it easy to handle and incorporate into various matrices. Its solubility profile is also a significant advantage: it is highly soluble in many common organic solvents such as ethanol, acetone, ethyl acetate, toluene, and methanol, but virtually insoluble in water. This characteristic is crucial for applications where water resistance is not required and compatibility with organic polymer systems or cosmetic oils is essential.

The high purity typically offered by reputable suppliers, often exceeding 99.0%, ensures consistent performance. Impurities are usually kept to a minimum, with individual impurities often below 0.1%. Its specific extinction coefficients at 285nm and 325nm are critical performance indicators for UV absorption efficiency, typically measuring above 630 and 400, respectively.

Understanding these chemical properties is vital for procurement managers and R&D scientists when selecting UV absorbers for applications ranging from polymer stabilization and protective coatings to personal care products. For those looking to buy CAS 131-57-7, sourcing from a reliable China manufacturer like us guarantees access to this scientifically robust and versatile UV absorber, ensuring optimal performance and product longevity.