The invention relates to the technical field of coatings, in particular to a bicomponent oily
polyurethane primer with low VOC (Volatile Organic Compounds) and a preparation method thereof. The primer comprises a component A, a component B and a diluting agent, wherein the ratio in parts by weight of the component A to the component B is 2:1, wherein the component A comprises polyhydric
alcohol resin with high
solid content, an ester
solvent, a dispersing agent, a matting
powder, a defoaming agent and an anti-
sediment agent; according to the preparation method, different molecular weights of the polyhydric
alcohol resin in the component A and the polyisocyanates in the component B are respectively screened, the optimal molecular weight is intercepted so as to ensure the dissolubility of the polyhydric
alcohol resin and the polyisocyanates in a
ketone solvent, meanwhile, other auxiliaries are used for carrying out stem
grafting improvement on a molecular structure to enhance the
miscibility of the two components; and therefore, the bicomponent oily
polyurethane primer not only has the characteristics of good application property, good water resisting property, high
hardness and thelike owned by the traditional
polyurethane paint, but also ensures that the content of the volatile organic compounds is greatly reduced and even is lower than 450g / L.