Griet Uytterhoeven

High-solids automotive coatings

Manufacturers of automotive repair finishes are tending to reduce more and more the level of volatile organic compounds in their paints in order to comply with increasingly strict environmental legislation After a review of the main parameters allowing a viscosity reduction in acrylic resins in general, this paper describes the use of a reactive intermediate called CARDURA E10 (a trade mark of the Royal Dutch group of companies) which is able to reduce the solution viscosity of different resins and, hence, allows to increase the solids content of automotive paints while improving the final coating properties

Ambient cure high solids acrylic resins for automotive refinish clear coat applications

There is nowadays an increasing demand for low VOC systems in automotive refinish industry. These systems should also cure sufficiently fast at ambient temperature in order to reduce the investment in drying equipment and the time of repair. However, matching the stringent chemical and mechanical requirements associated with medium solid systems, and reaching a VOC level <420 g/l (from UK and Dutch legislation) is a challenge, especially if the coatings are cured at room temperature. Extensive research has been carried out on high solids resins making use of CARDURA(1) E 10 (the glycidyl ester of VERSATIC acid) in conjunction with acrylic and methacrylic monomers. The efficient use of these building blocks allowed the cost-effective production of resins matching all coating requirements at a VOC level below 420 g/l after cure at ambient as well as elevated temperatures. These ambient cure clear coat systems exhibit a very good overall performance and should therefore form a good starting point for very high solids acrylic-urethane coatings for automotive refinish applications

Acid and scratch resistant coatings for melamine based OEM applications

Increasing the mar resistance of OEM clear coats has been one of the main R&D priorities of paint manufacturers over the last years. Reaching a good mar resistance level without compromising other coating properties such as acid resistance proves to be a major challenge. We investigated the use of branched glycidyl esters in melamine based OEM acrylic formulations. Our results show that systems based on this type of esters lead to good overall coating properties as well as a good balance between acid and scratch resistance.