US 12,378,433 B2
Aqueous coating composition comprising an epoxy resin-based paint base component
Anna Kondrat, Münster (DE); Beate Rohkamp, Münster (DE); Egbert Nienhaus, Münster (DE); Karin Wever, Münster (DE); Joerg Ressel, Münster (DE); Silke Przybilla, Münster (DE); Tim Voegeling, Münster (DE); Sibylle Schoeps, Münster (DE); Monika Tiggemann, Drensteinfurt (DE); and Sven Gosheger, Drensteinfurt (DE)
Assigned to BASF COATINGS GMBH, Muenster (DE)
Appl. No. 17/634,137
Filed by BASF Coatings GmbH, Münster (DE)
PCT Filed Aug. 7, 2020, PCT No. PCT/EP2020/072236
§ 371(c)(1), (2) Date Feb. 9, 2022,
PCT Pub. No. WO2021/032505, PCT Pub. Date Feb. 25, 2021.
Claims priority of application No. 19192480 (EP), filed on Aug. 20, 2019.
Prior Publication US 2022/0315792 A1, Oct. 6, 2022
Int. Cl. C09D 163/00 (2006.01); B05D 5/00 (2006.01); B05D 7/00 (2006.01); C09D 5/08 (2006.01)
CPC C09D 163/00 (2013.01) [B05D 5/005 (2013.01); B05D 7/572 (2013.01); B05D 7/576 (2013.01); C09D 5/08 (2013.01)] 4 Claims
 
1. A process for repairing a multicoat paint system having defects, comprising applying a coating composition in the region of the defects, curing the coating composition to produce a cured coating layer and then sanding the cured coating layer, wherein the coating composition is an aqueous two-component coating composition comprising
(1) an epoxy resin-based paint base component, and
(2) a polyamine-based curing component,
wherein the paint base component (1) comprises at least one aqueous dispersion of at least one pigment (P) and/or filler (F) in at least one epoxy resin (E),
and wherein the at least one epoxy resin (E) has
(i) a maximum sedimentation rate of not more than 17,500 micrometers per hour (measured in an optical cuvette centrifuge at an acceleration of 2050 g, solids diluted to 30% with water) and a glass transition temperature of less than 0° C. (measured by means of dynamic differential calorimetry, heating rate 10 K/min, 2nd measurement run), or
(ii) a maximum sedimentation rate of at least 12,500 micrometers per hour and a glass transition temperature of at least 0° C.