Scratch resistant PU (Poly Urethane) floor varnish and preparation method thereof

The invention relates to a scratch resistant PU (Poly Urethane) floor varnish and a preparation method thereof. The scratch resistant PU floor varnish is prepared from a first ingredient and a second ingredient at weight ratio of (0.8-1.2):(0.8-1.2), wherein the first ingredient is prepared from the following raw materials in parts by weight: 30-50 parts of hydroxy acrylic resin, 20-40 parts of high-hydroxyl number alkyd resin, 0.1-0.5 part of leveling agent, 0.1-0.5 part of antifoaming agent, 1-10 parts of epoxy resin, and 20-40 parts of composite environment-friendly solvent, and the second ingredient is prepared from the following raw materials in parts by weight: 10-40 parts of TDI-TMP, 10-30 parts of HDI (Hexamethylene Diisocyanate) tripolymer, 10-20 parts of moisture curing agent, and 30-50 parts of butyl acetate. By adopting the scratch resistant PU floor varnish disclosed by the invention, the scratch resistance of the varnish surface on the floor is obviously improved, while the other performances of transparency, storage stability and the like are rarely influenced; simultaneously the varnish film is uniform, smooth, and good in adhesion force; the number of the varnish coating layers can be reduced, therefore the cost is reduced; in addition, fracture is unlikely to form to influence the beautiful appearance of the floor.