BDK (CAS 24650-42-8)

Equivalent grades. The same substance is sold by other manufacturers as Omnirad BDK, Irgacure 651, Genocure BDK. It is the same CAS number (24650-42-8) and the same chemistry, so a formulation written around one of those grades transfers directly.

Introduction

BDK is specified for one reason more than any other: it survives heat. As a UV initiator it is competent but unremarkable, absorbing at 250 and 340 nm. What sets it apart is thermal stability, which matters in processes where the coating sees elevated temperature before, during or after the UV step.

Vacuum electroplating base coats are the classic case. The film has to survive a thermal cycle that would degrade a less stable initiator, and BDK holds its activity through it. If your process is entirely ambient, other grades will do the same job for less.

Physical & Chemical Properties

White crystalline powder. Molecular formula C16H16O3, molecular weight 256.30, purity ≥99.00% by HPLC, melting range 64–67 °C, loss on drying ≤0.50%. Absorption maxima at 250 nm and 340 nm.

Applications

Recommended at 3–5%. Well suited to UV-curing systems that must withstand elevated temperatures, notably vacuum electroplating base coatings and heat-resistant processes. Good solubility in common acrylate monomers and resin systems.

Regulatory status

BDK has no harmonised classification under CLP, so the hazard information on its SDS is the supplier's own self-classification. It is not on the REACH Candidate List, not restricted under Annex XVII, and not listed in Swiss Annex 10. It is known in the market under the older trade code 651.

Handling & Storage

Store sealed in a cool, dry, dark, ventilated area. Consult the SDS.

Packaging

20 kg cartons. COA per batch, SDS in English, samples available.