JPS6252035B2 - - Google Patents

Abstract

Plating defects may occur during the electrodeposition of nickel using compositions containing primary and secondary brighteners. According to the invention such defects are avoided by including 0.01 to 1 g/l of a sulfonated acetylenic compound or a salt of such a compound in an aqueous acidic nickel plating bath containing 0.2 to 10 g/l of saccharin, and 20 to 500 parts per million of Zn ions. The acetylenic bond and the sulfonate radical of the sulfonated acetylenic compound are connected by a carbon chain of at least one carbon atom and not more than 6 carbon atoms. The invention relates to the composition of such a bath, to the method of bright nickel plating using such a bath and to compositions for forming the bath.

Description

[Detailed description of the invention]

This invention relates to improved methods and compositions for the electrodeposition of nickel and its alloys. It has been found that the presence of zinc impurities tends to cause plating defects during electrodeposition of nickel electroplated objects using compositions containing primary and secondary brighteners. The above secondary brightener is saccharin (O-
The problem during plating is particularly serious when using benzoyl sulfimide). In this case, insufficient base metal coverage occurs in the low current density regions, resulting in an unsightly streaked (ridged) plating layer, as well as a dark, thin, non-metallic appearance plating layer, which is Not only does it impair the final appearance of the plated product, but also the acceptability of subsequent plating layers such as chrome plating.
Damage to appearance, gloss, etc. Sulfinic acids or hydroxysulfonates have been used to overcome the harmful effects of zinc in the presence of saccharin. Although such compounds reduce the above problems, their use also reduces the overall gloss and leveling of the plating layer. This necessitates the use of thicker nickel plating layers or higher levels of primary additives to obtain commercially acceptable plating layers. Another attempt was to replace saccharin with another class of additives, namely sodium benzenesulfonamide, sodium toluenesulfonate. Such class additives are not as sensitive to zinc impurities as satucalin, but are superior to satucalin in terms of stress reduction, brightening (in conjunction with class additives), and sulfur contribution (particularly important for double plating layers). Also inferior. It is an object of the present invention to provide a method and composition for plating nickel electrodeposits in the presence of saccharin and zinc impurities. It is also an object of the present invention to perform the above plating without affecting the gloss or leveling of the plating layer. In accordance with certain of its aspects, the invention comprises passing an electrical current from an anode to a cathode through an aqueous acidic electroplating solution containing (1) at least one nickel compound, (2) saccharin, and (3) zinc ions. In an improved method and composition for producing nickel or nickel alloy electrodeposit, a sulfonated acetylenic compound or a salt thereof, provided that the acetylene bond and the sulfonate group have at least one carbon atom and not more than 6 carbon atoms. linked by carbon chains). The concentrations of the above compounds are as follows: (1) Satucalin: 0.2 to 10 g/ (2) Zinc ion: 20 to 500 ppm (3) Sulfonated acetylene compound or its salt
...0.01-1.0g/The preferred range is as follows. (1) Satucalin...0.5-4.0g/ (2) Zinc ion...20-150ppm (3) Sulfonated acetylene compound or its salt
...0.2g/ Examples of the sulfonated acetylene compounds of the present invention include 2-butyne-1,4-disulfonic acid, 2-butynesulfonic acid, propynesulfonic acid, 1-butynesulfonic acid, and 1-pentynesulfonic acid. acids, but are not limited to these. The baths of the invention also contain an effective amount of at least one member selected from the group consisting of: (a) other brighteners added to saccharin; (b) brighteners; and (c) anti-pitting agents or wetting agents. sell. The term “brightener” is used by Modern
As described in Electroplating Volume 3, edited by F. Lowenheim, it includes aromatic sulfonates, sulfonamides, sulfonimides, etc., as well as aliphatic or aromatic-aliphatic olefinic unsaturated sulfonates, sulfonamides, sulfonimides, etc. It means to do. Specific examples of the above metallurgical additives are: (1) Disodium 1,5-naphthalene trisulfonate (2) Trisodium 1,3,6-naphthalene trisulfonate (3) Sodium benzene monosulfonate (4) Dibenzene sulfonimide (5) Sodium 3-chloro-2-butene-1-sulfonate (6) Sodium β-styrene sulfonate (7) Sodium allyl sulfonate (8) Monoallylsulfamide (9) Diallylsulfamide (10) Allylsulfonate Amide The above plating additive compounds may be used alone or in any suitable combination, but preferably about 0.5 to 10
g/g/g to provide the advantages described in the above-mentioned documents, which are known to those skilled in the art of nickel electroplating. The term “like brightener” is used by Moderm
As described in Electroplating, Part 3, edited by F. Lowenheim, reaction products of α-hydroxyacetylenic alcohols such as diethoxylated 2-butyne-1,4-diol and epoxy compounds, N-heterocyclic compounds, dyes, acetylene-based It is meant to include plating additive compounds such as amines and the like. Specific examples of the above plating additives are (1) 1,4-di-(β-hydroxyethoxy)-2
-Butyne(2) 1,4-di-(β-hydroxy-γ-chloropropoxy)-2-butyne(3) 1,4-di-(β-,γ-epoxypropoxy)-2-butyne(4) 1,4-di-(β-hydroxy-γ-butenoxy)-2-butyne(5) 1,4-di-(2′-hydroxy-4′-oxa-6′-heptenoxy)-2-butyne(6 ) N-(2,3-dichloro-2-propenyl)-
Pyridinium chloride (7) 2,4,6-trimethyl N-propargylpyridinium bromide (8) N-allylquinaldinium bromide (9) 2-butyne-1,4-diol (10) Propargyl alcohol (11) 2-methyl -3-Butyn-2-ol (12) Quinaldyl-N-propanesulfonic acid betaine (13) Butynoxyethanesulfonic acids (14) Propyneoxyethanesulfonic acids (15) Quinaldine dimethyl sulfate (16) N- Allylpyridinium bromide (17) Isoquinaldyl-N-propanesulfonic acid betaine (18) Isoquinaldine dimethyl sulfate (19) N-allylisoquinaldine bromide (20) 1,4-di-(β-sulfoethoxy)- 2-
Butyne (21) 3-(β-hydroxyethoxy)-propyne (22) 3-(β-hydroxypropoxy)-propyne (23) 3-(β-sulfoethoxy)-propyne (24) Phenosafranin (25) Fuchsin (26) Propargylamine (27) 1-diethylamino-2-propyne (28) 5-dimethylamino-2-methyl-3-pentyn-2-ol (29) 1-dimethylamino-2-pentyne (30) 1- Dimethylamino-2-butyne. Such brighteners, when used alone or in combination, desirably in amounts ranging from about 5 to 1000 mg/ml, may produce no visible effect on the electrodeposit or may produce a semi-gloss, fine-grained plating layer. However, best results are obtained when the brightener is used in conjunction with one or more brighteners to provide optimal plating layer gloss, degree of gloss, leveling, bright plating current density range, low current density coverage, etc. give. The term "anti-pitting agent or wetting agent" is meant to include substances that act to prevent or minimize gas pitting. Anti-pitting agents, when used alone or in combination, desirably in an amount in the range of about 0.05 to 1 g/g/g/g/kg, can act to emulsify, disperse, or dissolve contaminants such as oils, greases, etc. in baths. It can act more compatibly and thus facilitate obtaining a more solid plating layer. Preferred anti-pitting agents may include sodium lauryl sulfate, sodium lauryl ether-sulfate and sodium dialkyl sulfosuccinates. Nickel compounds used in nickel electrodeposition are typically added as sulfate, chloride, sulfamate, or fluoborate salts. Nickel sulfate, chloride, sulfamate and fluoborate salts are approximately 10 to 150
It is used in concentrations sufficient to provide nickel in the electroplating baths of the present invention at concentrations in the range of g/g/. The nickel electroplating bath of the present invention regulates the pH (e.g., about 3.0 to 5.0, preferably 0.4) and prevents burning at high current densities, such as about 30 to 60 g/
Preferably it may contain about 45 g/b of boric acid or other buffering agent. Solution agitation may be used to prevent "burning" of high current density regions and provide further temperature control of the solution. Air agitation, mechanical agitation, pump operation, cathode rods and other means of stirring the solution are all satisfactory. Furthermore, the solution can be operated without stirring. The operating temperature of the electroplating bath of the present invention is from about 40°C to about
It may be in the range of 70°C, preferably about 50°C to 62°C. Average cathode current density is about 0.5-12A per square dm
, with 3 to 6 A per square dm giving an optimum range. A typical aqueous nickel-containing electroplating solution (which may be used in combination with an effective amount of synergistic additives) contains the following: However, all concentrations are expressed in g/ unless otherwise specified.

[Table] During bath operation, the pH usually tends to increase, but it can be adjusted with acids such as hydrochloric acid, sulfuric acid, etc. The anode used in the bath may be an electrolyte or sulfur-containing nickel rod, strip or small chunk in a titanium basket. All anodes are usually covered with a coating or plastic bag of the desired porosity, thus containing a bath of metal particles, anode mud, etc., which can migrate mechanically or electrophoretically to the cathode and impart roughness to the cathode plating layer. Minimize introduction into the interior. The substrate to which the nickel electroplating layer of the present invention is applied may be a metal or metal alloy commonly electrodeposited and used in the electroplating field, such as nickel, cobalt, nickel-cobalt, copper, tin, brass, etc. . Other typical base metals from which the plated articles are made are ferrous metals such as iron, steel, steel alloys, copper, alloys of tin and its alloys, such as alloys with lead,
Alloys of copper, such as brass, bronze, etc., may include zinc, particularly zinc in the form of zinc-based die castings. All of these may be plated with other metals, such as copper. The base metal substrate may have a variety of surface finishes depending on the desired final appearance, which in turn depends on the gloss, brightness, leveling, thickness, etc. of the nickel electroplating applied to such substrate. do. It is in the electroplating of zinc-based die castings that the application of the present invention is particularly useful, since die castings enter the electroplating solution and produce high levels of zinc impurities. The above impurities in the presence of saccharin result in unsightly electrodeposits as mentioned above, which lead to high operating costs. Acetylene bond and sulfonate group have 1 or more carbon atoms
The addition or inclusion of a specific amount of a sulfonated acetylenic compound linked by six carbon chains or a salt thereof to an aqueous acidic nickel electroplating solution containing saccharin and zinc impurities can produce a high gloss without the above-mentioned drawbacks. yields a well-smoothed plating layer. The invention will be explained in more detail by the following examples.

【table】

Table Conditions for plating panels from the aqueous nickel electroplating composition described above were as follows: Zinc-coated steel test panels were stripped in 50% hydrochloric acid, rinsed, and then coated with 4/0 grit emerald.
It was sanded with a single horizontal pass of sanding paper, and similarly sanded with #2 grit emery sanding paper. The cleaned panel was injected into a full 267ml volume using the above composition at a cell current of 2 amps for 10 minutes using cathode bar agitation.
It was plated in a Hull Cell. Observation Panel 1 - Shows a glossy, well-smoothed plating layer but low current density skip plate, severe darkness and streaks. Panel 2 - Shows a shiny, well-smoothed plating layer over the entire current density range, with no defects. Panel 3 - Shows a shiny, well smoothed plating layer, but with very little low current density darkness.

Claims (1)

[Claims] 1. At least one nickel compound, 0.2g/
~10g/saccharin, and 20ppm~500ppm
A method for producing a shiny nickel-containing electrodeposit comprising passing an electric current from an anode to a cathode in an aqueous acidic plating solution containing zinc ions of 0.01 g/~1.0 g/ The above-mentioned production method comprises the presence of a sulfonated acetylene compound or a salt thereof, and the acetylene bond and the sulfonate group are connected by at least one carbon chain having 6 or less carbon atoms. 2. The manufacturing method according to claim 1, wherein the sulfonated acetylene compound is 2-butyne-1,4-disulfonic acid. 3. The manufacturing method according to claim 1, wherein the sulfonated acetylene compound is 2-butinsulfonic acid. 4. The manufacturing method according to claim 1, wherein the sulfonated acetylene compound is propynesulfonic acid. 5. The manufacturing method according to claim 1, wherein the sulfonated acetylene compound is 1-butinsulfonic acid. 6. The manufacturing method according to claim 1, wherein the sulfonated acetylene compound is 1-pentinesulfonic acid. 7 At least one compound providing nickel ions for electrodepositing nickel, 0.2 g/~10
g/g of saccharin, in an aqueous acidic electroplating solution containing 20 to 500 ppm of zinc ions, the presence of at least one sulfonated acetylene compound or its salt in an amount of 0.01 g/ to 1.0 g/ The electroplating liquid described above, characterized in that the acetylene bond and the sulfonate group are connected by a carbon chain having at least one and not more than 6 carbon atoms. 8. The electroplating solution according to claim 7, wherein the sulfonated acetylene compound is 2-butyne-1,4-disulfonic acid. 9. The electroplating liquid according to claim 7, wherein the sulfonated acetylene compound is 2-butinsulfonic acid. 10. The electroplating solution according to claim 7, wherein the sulfonated acetylene compound is propynesulfonic acid. 11. The electroplating liquid according to claim 7, wherein the sulfonated acetylene compound is 1-butinsulfonic acid. 12. The electroplating liquid according to claim 7, wherein the sulfonated acetylene compound is 1-pentinesulfonic acid.