The invention relates to a preparation method for an unsaturated
polyurethane coating.
Polyol is first dehydrated in advance, added with diisocyanate under the condition of adding catalyst and
diluent and then heated to 60 DEG C to 80 DEG C which is kept until the NCO content is 0.1 to 0.3 percent, so that a
polyurethane prepolymer is obtained, the
polyurethane prepolymer is then added with
polymerization inhibitor, uniformly mixed and then added with hydroxyl acrylic ester for end capping, mixing is carried out until the NCO content is zero,
photoinitiator,
antioxidant,
ultraviolet absorber, leveling agent and defoaming agent are then added, composition is then spin-sprayed on a substrate material, and after
light curing for film formation, the unsaturated
polyurethane coating is obtained. The preparation method introduces the unsaturated
double bond of acrylic ester into the polyurethane
system, moreover, a prepolymerization method is adopted to increase the molecular weight of the resin among the
coating components to 5000 to 20000, the
coating is attached well to the surface of the transparent substrate by
light curing, the time of coating curing is shortened, consequently, the acceptability of the finished product is increased, and the production cost is reduced.