▎ 摘　　要

NOVELTY - Rare earth flame-retardant complex derivative of (I) is new. USE - Rare earth flame-retardant complex derivative of formula (I) used as polymer material (claimed), and in fields of engineering plastics, macromolecule film, coating, rubber. ADVANTAGE - The rare earth flame-retardant complex derivative of formula (I) has excellent flame-retardant synergistic performance and is matched with phosphorus-nitrogen series; improves flame retardant efficiency or property of product; and reduces addition amount of phosphorus-nitrogen flame retardant. DETAILED DESCRIPTION - Rare earth flame-retardant complex derivative of formula (I) is new. Ln is yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb) and dysprosium (Dy). INDEPENDENT CLAIMS are included for: (1) a method for preparing rare earth flame-retardant complex derivative of formula (I); (2) a flame-retardant polymer material, which comprises rare earth flame-retardant complex derivative of formula (I), high polymer material, halogen-free flame retardant, anti-dripping agent and processing auxiliary agent.