Zinc and zinc alloy electroplating bath and process

Claim 1

An aqueous bath suitable for electrodepositing zinc and zinc alloys on a conductive substrate comprising zinc ions present in an amount sufficient to electrodeposit zinc, and in the case of a zinc alloy, additional metal ions selected from the group consisting of nickel, cobalt and iron present in an amount to electrodeposit an alloy of zinc and nickel, zinc and cobalt, zinc, nickel and cobalt; zinc and iron, zinc, iron and nickel; zinc, iron and cobalt; and a brightening amount of a bath soluble AB polyamide brightener of the structural formula: ##STR19## Z is --H, or ##STR20## Q is --O--R 4 , --NR 5 R 6 , or, --OM; R 1 and R 2 are the same or different and are --H, --OH, an alkyl group of 1-4 carbons, an aryl group, ##STR21## R 3 is ##STR22## R 4 , R 5 and R 6 are the same or different and are --H, or an alkyl, alkenyl, alkynyl, alkanol, alkenol, alkynol, keto alkyl, keto alkenyl, keto alkynyl, alkamine, alkoxy, polyalkoxyl, sulfoalkyl, carboxy-alkyl, mercapto alkyl, or nitriloalkyl group having from 1 to about 12 carbon atoms, phenyl, or substituted phenyl, or, ##STR23## where f+i=3; R 7 is --H, --OH, or a hydroxyalkyl group having from 1-4 carbons; R 8 is --H, or an alkyl, alkanol, or alkamine group, having from 1-4 carbons, or ##STR24## R 9 , R 10 and R 11 are the same or different and are --H, or an alkyl group of 1-4 carbons; R 12 is --H, or an alkanol, alkamine, sulfoalkyl, carboxyalkyl, hydroxyaryl, sulfoaryl, carboxyaryl, or aminoaryl having from 1 to about 10 carbons; or, ##STR25## R 13 is --H, alkyl, alkenyl, or, alkynyl of 1-4 carbons or, --CH 2 --O--R 14 ; R 14 is --H, alkyl, alkenyl, or alkynyl of 1-4 carbons; M is H, Li, Na, K, Be, Mg, or Ca; X is ##STR26## U and U' are the same or different and are H, Cl, Br, F, --NO 2 , --SO 3 M, or, --O--R 4 ; Y is --O--R 12 , --N(R 12 ) 2 , --SO 3 M, --CO 2 M, --SR 12 , --CN, or, Y', except in the special case where: b=c=0, and d=2, then Y is limited to being selected from the group defined for Y'; Y' is --H, ##STR27## a is 0 or 1; b is an integer from 0 to 11; c is 0 or 1; d is an integer from 0 to 2; e is an integer from 0 to 6; f is an integer from 1 to 3; g is an integer from 1 to 30; h is an integer from 2 to 5; and i is an integer from 0 to 2; as well as mixtures thereof, wherein said constituents and the number thereof are selected so that the compound contains at least two amide groups.