PREPARATION METHOD OF POLYURETHANE FOAM FOR NON-FLAMMABLE PANEL

摘要

PURPOSE: A method for preparing a polyurethane foam for a non-flammable(KSF 2271) panel is provided, to improve adhesive strength to metal and productivity. CONSTITUTION: The method comprises the steps of reacting a resin premix comprising 55-78 wt% of a mixed polyol which comprises 25-75 wt% of a polyester polyol and 25-75 wt% of a polyether polyol having a OH value of 200-300 mg KOH/g and has a OH value of 250-350 mg KOH/g; 0.5-3.0 wt% of a urethane reactive catalyst; 5-10 wt% of a flame retardant; 0.5-2.0 wt% of a silicone surfactant; 1.0-3.0 wt% of a trimerization catalyst; 15-25 wt% of a foaming agent; and 0-2 wt% of water, with polyisocyanate within an isocyanate index of 2.5-3.5. Preferably the polyisocyanate is polymethylene diphenyl diisocyanate or an isocyanate obtained by modifying polymethylene diphenyl diisocyanate with an aliphatic or aromatic polyalkylene oxide, and the content of isocyanate groups is 30-32 wt%.