| abstract |
A method for preparing an unsaturated polyurethane coating comprises the following steps: firstly dehydrating polyol in advance, adding diisocyanate under the condition of adding catalyst and diluent, then heating to 60-80 DEG C and keeping the temperature until the NCO content is 0.1-0.3% to obtain Polyurethane prepolymer, then add polymerization inhibitor in turn, add hydroxy acrylate end cap after mixing uniformly, stir and mix until the NCO content is 0, then add photoinitiator, antioxidant, UV absorber, leveling agent, The defoamer is then suspended and coated on the base material, and the unsaturated polyurethane coating is obtained after photo-curing to form a film. In the present invention, the unsaturated double bond of acrylate is introduced into the polyurethane system, and the molecular weight of the resin in the coating component is increased to 5000-20000 by means of prepolymerization, and the coating is well adhered to the surface of the transparent substrate through light curing. . The curing time of the coating is shortened, thereby improving the yield of finished products and reducing the production cost. |