A water-borne basecoat system for vehicle refinishes is presented. The system consists of pigment concentrates called mixing bases and a mixing clear. The basecoat paints show a VOC level of less than 420 g/l. The paints can be applied by high volume low pressure spray guns, an equipment that guarantees very low overspray. The rheological behaviour of these basecoats is controlled by the use of thixotropic silicate. The chemical base of the mixing clear and the mixing bases is a special set of polyurethane resins, which enable an excellent orientation of the metallic pigments and favourable grinding properties for high hiding power. The synthesis of the polyurethane resin of the mixing bases is described in an eater process as an alternative to the well-known ketone process. This basecoat system is commercialized under the trade name of Glasurit(R) as 90 Line. (C) 1998 Elsevier Science S.A. All rights reserved.
