Method for the production and repair of multicoat special-effect coatings

US5820986A · kind A · utility

Assignee

• Basf Lacke & Farben Aktiengesellschaft · DE

Inventors

• Heinz Topfel · Würzburg, DE
• Ewald Bischoff · Uettingen, DE
• Harry Libutzki · Himmelstadt, DE
• Jorge Wellmann · Munster, DE
• Dieter Herbst · Würzburg, DE
• Hans-Joachim Streitberger · Munster, DE

Key dates

• Filing date: Feb 18, 1997
• Grant date: Oct 13, 1998
• Expiry date: Feb 18, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31504
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The invention relates to a method for the production and repair of multicoat special-effect coatings, in which the basecoat is produced exclusively by elecrostatic spraying, a coating material with a specific rheological behavior is employed as the basecoat and the repair is carried out with the aid of a spray application process in which a spray jet is produced which is distinguished in that PA1 at most 40% of the coating droplets passing a measurement point which lies at the center of the spray jet and 300 mm away from the nozzle have a diameter which is less than 20 .mu.m and at least 5% of the coating droplets have a diameter which is greater than 60 .mu.m, PA1 at least 20% of the coating droplets passing the measurement point have a speed which is less than 6 m/s and at most 30% of the coating droplets have a speed of more than 10 m/s, and PA1 the coating droplets have a momentum which is equal to at least 4.times.10.sup.-5 g cm s.sup.-1, the diameter and the speed having been determined with the aid of the Doppler phase anemometry method.