Coating articles with pigmented primer then top-coat and drying

摘要

In a process wherein a primer contg. a colouring and.or metal-contg. pigment is applied to a substrate followed by a topcoat contg. an OH-contg. resin and polyisocyanate and the coats are hardened at from room temp. to 140 deg. C the primer contains as vehicle A) a resin contg. an OH gp. and a COOH gp., or B) a resin contg. an OH gp. and a catalyst (I) for reaction between OH gp. of the resin and NCO gps. of the polyisocyanate in the topcoat, or C) a resin contg. an OH gp. and a COOH gp. and a (I). Pref. primer is organic solvent-based or is aq. Primer comprises resin with an OH gp., or an OH and a COOH gp., and a (I). Resin contg. both an OH and a COOH gp. is acrylic (modified by chlorinated polyolefin) or polyester resin. Resin contg. OH and opt. a COOH gp. has OH no. 5-200, esp. 15-100. Esp. primer is organic solvent based and resin has OH and COOH gp. with acid no. 2-30, or is water-based and resin has OH and COOH gp. with acid no. 1-200.