Bismuth containing electrocoating material with improved catalytic activity

An aqueous electrocoating material (ECM) comprising

• (a) at least one binder B1 containing cationic or anionic groups and reactive functional groups which are able to undergo crosslinking reactions
• with complementary reactive functional groups present in a crosslinking agent (b), wherein the reactive functional groups are hydroxy groups
• (b) at least one crosslinking agent CA comprising the complementary reactive functional groups,
• (c) at least one bismuth compound and
• (d) at least one binder B2, said binder B2 being different from the at least one binder B1 and being obtained by reacting:
• (d-1) at least one compound C1 containing at least one epoxy group with
• (d-2) at least one hydroxy group containing compound C2 and
• (d-3) at least one compound C3 of general formula (I)
• R1R2N—(CH2)a—O—[CH2—CH(R3)]b—OH (I)
• wherein
• R1, R2 independently from each other, are hydrogen or a C1-C4 alkyl residue;
• R3 is hydrogen or a C1-C4 alkyl residue;
• a is an integral number of 1 to 8;
• and
• b is an integral number of 1 to 4;
• and
• (d-4) optionally at least one compound C4 comprising at least one primary and at least one tertiary amino group,
• characterized in that
• the molar ratio of compound C3 of general formula (I) to the at least one compound C1 containing at least one epoxy group is 1:1 to 1:2.5.