Copper salts for laser marking of thermoplastic compositions

摘要

A laser markable thermoplastic composition which contains a copper phosphate salt such as copper phosphate, copper sulfate, cupric hydroxide phosphate and copper thiocyanate. The copper phosphate salt is preferably added in an amount ranging from about 0.1 to 5 parts by weight and the copper phosphate salt preferably has a particle size less than 10 mu m. The laser markable thermoplastic composition can be laser marked to provide a visibly distinct and separately identifiable region which preferably differs in overall color from the base material by a Delta E value of at least 10-20.