US4388160A — Zinc-nickel alloy electroplating process

Claim 1

Independent Claim 361 words

A process for applying to a workpiece a bright zinc-nickel alloy electroplated deposit having superior corrosion resistance, said process comprising: (1) preparing an aqueous bath comprising, on a per liter basis: (a) a soluble zinc compound providing 30 to 100 grams of zinc as metal and selected from the group consisting of zinc chloride and zinc oxide; (b) a soluble nickel salt providing up to 10 grams of nickel as a metal, said soluble nickel salt being nickel chloride; (c) an ammoniated electrolyte providing up to 5 grams of ammonium ions, said ammoniated electrolyte being ammonium chloride; (d) a non-ammoniated electrolyte selected from the group consisting of potassium chloride and sodium chloride, said non-ammoniated electrolytes providing 25 to 300 grams of chloride ions; (e) 5-50 grams of polyoxyalkylated surfactant selected from the group consisting of: block copolymers of ethylene oxide and linear alcohols having the following structure formula; ##STR3## wherein x is an integer from 9 to 15 and n is an integer from 10 to 50; block copolymers of ethylene oxide and phenol alcohols having the following structural formula; ##STR4## wherein x is an integer from 6 to 15 and n is an integer from 10 to 50; block copolymers of ethylene oxide and monothanol amine coconut fatty acid condensate; alkoxylated alkyl phenols, alkoxylated alkyl naphthols, alkoxylated aliphatic monohydric alcohols, alkoxylated polyoxypropylene glycols, alkoxylated 2,4,7,9,-tetramethyl-5-decyne-4,7-diol, alkoxylated ethylene diamine, alkoxylated fatty acids, alkoxylated amides, alkoxylated esters; and (f) 0.05-4 grams of an aromatic carbonyl brightener; (g) 10-40 grams of boric acid; and (h) 1.5-15 grams of an aromatic carboxylic acid; (2) maintaining acid conditions in the bath with a pH of at least 3; (3) maintaining said bath at a temperature of from about 10° to about 30° C.; (4) causing codeposition of the nickel and zinc to form a zinc-nickel alloy electrodeposit on the workpiece; and (5) controlling the amount of nickel ions during operation of the bath to limit the deposition of nickel and to cause deposition of a zinc-nickel alloy electroplate containing at least 96 percent by weight of zinc and an amount of nickel from 0.1 to 4 percent by weight effective to provide superior corrosion resistance.

Claim 2

Dependent Claim 361 words

A process for applying to a workpiece a bright zinc-nickel alloy electroplated deposit having superior corrosion resistance, said process comprising: (1) preparing an aqueous bath comprising, on a per liter basis: (a) a soluble zinc compound providing 30 to 100 grams of zinc as metal and selected from the group consisting of zinc chloride and zinc oxide; (b) a soluble nickel salt providing up to 10 grams of nickel as a metal, said soluble nickel salt being nickel chloride; (c) an ammoniated electrolyte providing up to 5 grams of ammonium ions, said ammoniated electrolyte being ammonium chloride; (d) a non-ammoniated electrolyte selected from the group consisting of potassium chloride and sodium chloride, said non-ammoniated electrolytes providing 25 to 300 grams of chloride ions; (e) 5-50 grams of polyoxyalkylated surfactant selected from the group consisting of: block copolymers of ethylene oxide and linear alcohols having the following structure formula; ##STR3## wherein x is an integer from 9 to 15 and n is an integer from 10 to 50; block copolymers of ethylene oxide and phenol alcohols having the following structural formula; ##STR4## wherein x is an integer from 6 to 15 and n is an integer from 10 to 50; block copolymers of ethylene oxide and monothanol amine coconut fatty acid condensate; alkoxylated alkyl phenols, alkoxylated alkyl naphthols, alkoxylated aliphatic monohydric alcohols, alkoxylated polyoxypropylene glycols, alkoxylated 2,4,7,9,-tetramethyl-5-decyne-4,7-diol, alkoxylated ethylene diamine, alkoxylated fatty acids, alkoxylated amides, alkoxylated esters; and (f) 0.05-4 grams of an aromatic carbonyl brightener; (g) 10-40 grams of boric acid; and (h) 1.5-15 grams of an aromatic carboxylic acid; (2) maintaining acid conditions in the bath with a pH of at least 3; (3) maintaining said bath at a temperature of from about 10° to about 30° C.; (4) causing codeposition of the nickel and zinc to form a zinc-nickel alloy electrodeposit on the workpiece; and (5) controlling the amount of nickel ions during operation of the bath to limit the deposition of nickel and to cause deposition of a zinc-nickel alloy electroplate containing at least 96 percent by weight of zinc and an amount of nickel from 0.1 to 4 percent by weight effective to provide superior corrosion resistance.

Claim 3

Dependent Claim 47 words

A process according to claim 1, wherein said bath is substantially free of ammonium ions and has a pH from about 3.0 to about 4.5 and contains at least 0.5 grams per liter of an aromatic aldehyde and at least 3 grams per liter of nickel chloride.

Claim 4

Dependent Claim 341 words

A process for applying to a workpiece a bright zinc-nickel alloy electroplated deposit having superior corrosion resistance, said process comprising: (1) preparing an aqueous bath comprising, on a per liter basis: (a) a soluble zinc compound providing 30 to 100 grams of zinc as metal and selected from the group consisting of zinc chloride and zinc oxide; (b) a soluble nickel salt providing up to 10 grams of nickel as a metal, said soluble nickel salt being nickel chloride; (c) an ammoniated electrolyte providing 1-10 grams of ammonium ions, said ammoniated electrolyte being ammonium chloride; (d) a buffer; (e) a non-ammoniated electrolyte selected from the group consisting of potassium chloride and sodium chloride, said non-ammoniated electrolytes providing 25 to 300 grams of chloride ions; (f) 5-50 grams of a polyoxyalkylated surfactant selected from the group consisting of: block copolymers of ethylene oxide and linear alcohols having the following structural formula; ##STR5## wherein x is an integer from 9 to 15 and n is an integer from 10 to 50; block copolymers of ethylene oxide and phenol alcohols having the following structural formula; ##STR6## wherein x is an integer from 6 to 15 and n is an integer from 10 to 50; block copolymers of ethylene oxide and monoethanol amine coconut fatty acid condensate; alkoxylated alkyl phenols, alkoxylated alkyl naphthols, alkoxylated aliphatic monohydric alcohols, alkoxylated polyoxproypylene glycols, alkoxylated 2,4,7,9-tetramethyl-5-decyne-4,7-diol, alkoxylated ethylene diamine, alkoxylated fatty acids, alkoxylated amides, alkoxylated esters; and (g) 0.05-4 grams of an aromatic carbonyl compound; (2) maintaining acid conditions in the bath with a pH of at least about 4; (3) maintaining said bath at a temperature of at least 10° C.; (4) causing codeposition of the nickel and zinc to form a zinc-nickel alloy electroplated deposit on the workpiece; and (5) controlling the amount of nickel ions and ammonium ions in the bath to limit the deposition of nickel and to cause deposition of a zinc-nickel alloy electroplate containing at least 96 percent by weight of zinc and an amount of nickel effective to provide superior corrosion resistance.

Claim 5

Dependent Claim 341 words

A process for applying to a workpiece a bright zinc-nickel alloy electroplated deposit having superior corrosion resistance, said process comprising: (1) preparing an aqueous bath comprising, on a per liter basis: (a) a soluble zinc compound providing 30 to 100 grams of zinc as metal and selected from the group consisting of zinc chloride and zinc oxide; (b) a soluble nickel salt providing up to 10 grams of nickel as a metal, said soluble nickel salt being nickel chloride; (c) an ammoniated electrolyte providing 1-10 grams of ammonium ions, said ammoniated electrolyte being ammonium chloride; (d) a buffer; (e) a non-ammoniated electrolyte selected from the group consisting of potassium chloride and sodium chloride, said non-ammoniated electrolytes providing 25 to 300 grams of chloride ions; (f) 5-50 grams of a polyoxyalkylated surfactant selected from the group consisting of: block copolymers of ethylene oxide and linear alcohols having the following structural formula; ##STR5## wherein x is an integer from 9 to 15 and n is an integer from 10 to 50; block copolymers of ethylene oxide and phenol alcohols having the following structural formula; ##STR6## wherein x is an integer from 6 to 15 and n is an integer from 10 to 50; block copolymers of ethylene oxide and monoethanol amine coconut fatty acid condensate; alkoxylated alkyl phenols, alkoxylated alkyl naphthols, alkoxylated aliphatic monohydric alcohols, alkoxylated polyoxproypylene glycols, alkoxylated 2,4,7,9-tetramethyl-5-decyne-4,7-diol, alkoxylated ethylene diamine, alkoxylated fatty acids, alkoxylated amides, alkoxylated esters; and (g) 0.05-4 grams of an aromatic carbonyl compound; (2) maintaining acid conditions in the bath with a pH of at least about 4; (3) maintaining said bath at a temperature of at least 10° C.; (4) causing codeposition of the nickel and zinc to form a zinc-nickel alloy electroplated deposit on the workpiece; and (5) controlling the amount of nickel ions and ammonium ions in the bath to limit the deposition of nickel and to cause deposition of a zinc-nickel alloy electroplate containing at least 96 percent by weight of zinc and an amount of nickel effective to provide superior corrosion resistance.

Claim 6

Dependent Claim 22 words

A process according to claim 3, wherein the amount by weight of ammonium ions is greater than the amount of nickel ions.

Claim 7

Dependent Claim 225 words

An electroplating process comprising preparing an aqueous acid plating bath containing, on a per liter basis, a soluble zinc compound providing 30 to 100 grams of zinc as metal and selected from the group consisting of zinc chloride and zinc oxide; an effective amount of a soluble nickel salt providing up to 10 grams of nickel as a metal, said nickel salt being nickel chloride; a non-ammoniated electrolyte providing 25 to 300 grams of chloride ions, said electrolyte being selected from the group consisting of potassium chloride and sodium chloride; a minor amount of an ammoniated electrolyte providing at least 5 grams of ammonium ions, said ammoniated electrolyte being ammonium chloride; from 5 to 50 grams of a polyoxyethylene surfactant; and from 0.05 to 4 grams of an aromatic carbonyl brightener; maintaining the bath under acid conditions with a pH of at least 3; controlling the amounts of nickel and ammonium ions to limit the rate of deposition of nickel; and simultaneously limiting the difference in the deposition potentials of the nickel and zinc to cause codeposition of nickel and zinc and formation on the surface of the workpiece of a bright zinc-nickel alloy electroplate containing at least 96 percent by weight of zinc and an amount of nickel from 0.1 to 4 percent by weight such that the electrodeposit has vastly improved corrosion resistance.

Claim 8

Dependent Claim 225 words

An electroplating process comprising preparing an aqueous acid plating bath containing, on a per liter basis, a soluble zinc compound providing 30 to 100 grams of zinc as metal and selected from the group consisting of zinc chloride and zinc oxide; an effective amount of a soluble nickel salt providing up to 10 grams of nickel as a metal, said nickel salt being nickel chloride; a non-ammoniated electrolyte providing 25 to 300 grams of chloride ions, said electrolyte being selected from the group consisting of potassium chloride and sodium chloride; a minor amount of an ammoniated electrolyte providing at least 5 grams of ammonium ions, said ammoniated electrolyte being ammonium chloride; from 5 to 50 grams of a polyoxyethylene surfactant; and from 0.05 to 4 grams of an aromatic carbonyl brightener; maintaining the bath under acid conditions with a pH of at least 3; controlling the amounts of nickel and ammonium ions to limit the rate of deposition of nickel; and simultaneously limiting the difference in the deposition potentials of the nickel and zinc to cause codeposition of nickel and zinc and formation on the surface of the workpiece of a bright zinc-nickel alloy electroplate containing at least 96 percent by weight of zinc and an amount of nickel from 0.1 to 4 percent by weight such that the electrodeposit has vastly improved corrosion resistance.

Claim 9

Dependent Claim 22 words

A process according to claim 3 or claim 5 wherein the amount of said ammoniated electrolyte is from 5 to 10 grams.

Claim 10

Dependent Claim 22 words

A process according to claim 3 or claim 5, wherein the amount of said nickel salt is from 1 to 10 grams.

Claim 11

Dependent Claim 29 words

A process according to claim 7 wherein the electrolyte is predominantly potassium chloride and is present in the bath in an amount of at least 180 grams per liter.

Claim 12

Dependent Claim 50 words

A process according to claim 8 wherein the pH of the bath during plating is at least 4 and the bath is controlled to limit the amount of nickel consumed and to provide a zinc-nickel alloy electroplate with an alloy nickel content of from about 0.1 to about 4 percent.

Claim 13

Dependent Claim 34 words

A process according to claim 8 wherein the amount of the nickel salt is at least 3 grams per liter, and the amount of the zinc compound is at least 50 grams per liter.

Claim 14

Dependent Claim 47 words

A process according to claim 7 wherein the pH of the bath is from about 3 to about 4.5 and the amounts of the nickel and ammonium ions are controlled to provide bright alloy electrodeposits containing from about 1 to about 3 percent by weight of nickel.

Claim 15

Dependent Claim 24 words

A process according to claim 7 wherein said surfactant is a nonionic polyoxyalkylated compound containing at least 15 alkylene oxide groups in the molecule.

Claim 16

Dependent Claim 37 words

A process according to claim 7 wherein the bright zinc-nickel alloy electrodeposit on the workpiece has an alloy nickel content of at least about 1 percent by weight and is provided with a subsequent chromate conversion coating.

Claim 17

Dependent Claim 21 words

A process according to claim 3 or claim 5, wherein said surfactant comprises an interpolymer of ethylene oxide and propylene oxide.

Claim 18

Dependent Claim 28 words

A process according to claim 3 or claim 5, wherein the chloride ion concentration is maintained at at least 200 grams per liter during operation of the bath.

Claim 19

Dependent Claim 25 words

A process according to claim 3 or claim 5, wherein the zinc compound provides from about 50 to about 80 grams per liter of zinc.

Claim 20

Dependent Claim 60 words

A process according to claim 3 or claim 5, wherein the amount by weight of nickel in the bath is at least 3 grams per liter and the bath is controlled to form a bright zinc nickel alloy electrodeposit containing no more than a few percent of nickel which, when subjected to chromate post treatment, has vastly improved corrosion resistance.

Claim 21

Dependent Claim 37 words

A process according to claim 3 or claim 5, wherein said bath contains at least 10 grams per liter of boric acid and from about 1.5 to about 15 grams per liter of an aromatic carboxylic acid.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1986-06-13	1986-12-13	1987-06-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1990-06-13	1990-12-13	1991-06-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1994-06-13	1994-12-13	1995-06-14	$7700.00	Window Closed / Lapsed

Zinc-nickel alloy electroplating process

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