METAL PRETREATMENT MODIFICATION FOR IMPROVED THROWPOWER Russian patent published in 2018 - IPC C23C22/34 C23C22/80 C23C22/83 C25D13/20 

FIELD: chemistry.

SUBSTANCE: invention relates to the treatment of a metallic substrate before painting. In the method, the composition for treating a metal substrate comprises: (a) a group IV(b) metal ion,

(b) a copper ion, (c) a fluoride ion, (d) an organophosphonic acid and (e) a carrier – an aqueous medium. Wherein (a) is provided from a compound of zirconium, titanium or hafnium or from mixtures thereof, (b) is present in an amount of from 5 to 40 ppm based on elemental copper and the total weight of the composition, and the organic group of organophosphonic acid has six or less carbon atoms. This composition has a pH of from 3 to 7. Such method for coating a metal substrate includes (a) pretreating the metal substrate with a composition with a group IV(b) metal ion, followed by (b) treating the substrate from step (a) with said composition for treating a metal substrate, followed by (c) electrodeposition on the substrate from step (b) of the cationic electrodepositable composition.

EFFECT: invention provides an increase in the coating power of the applied cationic electrodepositable coating composition.

17 cl, 2 dwg, 3 tbl