▎ 摘　　要

NOVELTY - Flame-retardant polyurethane rigid foam comprises 15-25 pts. wt. polyether polyol, 10-20 pts. wt. polyethylene glycol, 100-125 pts. wt. isocyanate, 1-5 pts. wt. water, 0.1-0.8 pts. wt. catalyst, 1-3 pts. wt. foam stabilizer, 2-5 pts. wt. graphite material, 2-10 pts. wt. solid phase phosphorus flame retardant, 3-10 pts. wt. gas phase phosphorus flame retardant, and 1-3 pts. wt. gas-solid two-phase phosphorus flame retardant. USE - The flame-retardant polyurethane rigid foam is useful in the field of thermal insulation materials (claimed). ADVANTAGE - The flame-retardant polyurethane rigid foam has an oxygen index of 31.1%, a flame-retardant grade of V0, and excellent flame-retardant properties. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the flame-retardant polyurethane rigid foam comprising mixing polyether polyol, polyethylene glycol, water, catalyst, foam stabilizer, graphite material, solid phase phosphorus flame retardant, gas phase phosphorus flame retardant, gas-solid two-phase phosphorus flame retardant and isocyanate, casting, foaming and curing are carried out in sequence.