DE1008543B - Bath for galvanic nickel plating - Google Patents

Description

GERMAN

The invention relates to improvements in the electrodeposition of nickel from aqueous acidic Baths and refers in particular to the use of mixtures of certain types of substances to adjust the grain size to reduce and increase the gloss of the nickel plating or deposit, and the invention is mainly concerned with the production of galvanic deposits of shiny, pliable nickel coatings of high gloss.

According to the invention, a bath for the electrodeposition of shiny nickel has an aqueous acidic one A solution of a nickel salt containing 0.003 to 0.08 g / l of a soluble compound of the following formula:

(R ₂ ) ,, - Ar - CHZ- NX - (R ₁ ),

Herein, NX denotes the radical of a quinoline or isoquinoline nucleus or a corresponding nucleus which contains a methyl or ethyl substitution group on a core carbon atom, A an anion of a water-soluble acid, R ₁ a halogen atom, R ₂ a halogen atom or a nitro, methyl or Fluoromethyl group, Ar a benzene or naphthalene radical, Z hydrogen, methyl or ethyl, χ and y equal to zero, 1 or 2.

The compound further contains up to 1.5% of ^an organic sulfonamide, sulfonimide or a sulfonic acid.

The invention is based on the experience that particularly favorable results are achieved in that together in the nickel plating bath one or more substances defined in the above formula and in the the following Table I (which are added as such or put in place only in the bath itself are formed) in connection with one or more sulfonamides explained in the following Table II, Sulfonimides or sulfonic acids can be used.

In the above general formula, R ₁ can be chlorine, bromine or iodine, but is preferably chlorine or bromine, and Z is preferably a hydrogen atom.

The anion represented by A can e.g. B. Cl ', Br', Γ, SO ₄ ", CH ₃ SO / or the anion contained in the acetates, citrates or tartrates. Particularly valuable compounds are those where A is a bromine or chlorine ion.

As indicated, R _{1 is} halogen and R ₂ can be halogen, and since χ and y can be zero, 1 or 2 the compounds can e.g. B. 1 or 2 halogen nucleus atoms both in the heterocyclic nucleus and in the benzene or naphthalene nucleus, or where both χ and y are zero, the nuclei mentioned are unsubstituted. Excellent results are achieved with compounds in which χ and y are equal to zero or in which R _{1 is} chlorine or bromine, R _{2 is} chlorine, bromine or nitrogen and χ is zero and y is 1 or in the case of a bath for galvanic nickel plating

Applicant:

The Udylite Corporation,
Detroit, me. (V. St. A.)

Representative: Dr.-Irug H. Negendank, patent attorney,
Hamburg 36, Neuer Wall 41

Henry Brown, Huntington Woods, Mich.,

and Leroy Bertolet High, Detroit, Mich. (V. St. A.),

have been named as inventors

where χ is 1 and y is zero or where both χ and y are 1 and especially where Ar is a benzene radical.

Quinoline and isoquinoline compounds used in accordance with the invention are represented by the following formulas:

Quinoline compounds

Isoquinoline compounds

In these structural formulas, the letters A, R ₁ , R ₂ , Z and χ and y have the meanings given above.

Under all circumstances, the connecting lines _{emanating from the radicals R 1} and R ₂ indicate that these radicals can be substituted at any point on the ring of the quinoline or isoquinoline radical.

Of particular value are N-Benzyl-2-methylquinoline chloride, N-benzyl-3-meiriylisoquinoline chloride, N-benzyl-1-methylisoquinoline chloride, the corresponding naphthalyl compounds and the mono-nitro derivatives, that is, where the nitro group is in the benzene nucleus of the benzyl radical is e.g. B. N-4-nitrobenzylquinoline chloride or bromide.

709 509/353

Table I.

link

No.

Optimal

concentration

in g / l

1.
2.
3.

4th

5.
6th
7th

9.
10.
11.
12th

13th

N-Benzylquinoline Chloride ...
N-benzylisoquinoline chloride.

N-benzylquinoline sulfate

N-benzyl-2-methylquinoline-

chloride

N-benzyl-2: 6-dimethyl-

quinoline bromide

N-benzyl-2-chloroquinoline

chloride

N-benzyl-2-bromoquinoline-

bromide

N-benzyl-6-chloroquinoline-

bromide

N-benzyl-2: 4-dimethyl-

quinoline chloride

N-benzyl-2: 4-dichloro-

quinoline chloride,

N-benzyl-2: 8-dimethyl-

quinoline chloride

N-benzyl-5: 8-dimethyl-

quinoline chloride

N-benzyl-1: 3-dimethyliso-

quinoline chloride

N-benzyl-8-methylquinoline-

chloride

N-Benzyl-S-chloro ^ -methyl-

quinoline chloride

N-benzyl-3-brorno-2-methyl-

quinoline bromide

N-benzyl-3-methyliso-

quinoline chloride

N-4-nitrobenzylquinoline-

bromide

N-2: 4-dinitrobenzyliso-

quinoline bromide

N-4-chlorobenzylquinoline-

chloride

N-a-methylnaphthalene-

quinoline chloride

N-a-methylnaphthalene iso-

quinoline chloride

m-trifluoromethylbenzyl

quinoline bromide

m-Trifluoromethylbenzylisoquinoline chloride

0.01 to 0.04 0.01 to 0.04 0.01 to 0.04

0.005 to 0.04 0.005 to 0.04 0.01 to 0.04 0.01 to 0.04 0.01 to 0.04 0.005 to 0.04 0.01 to 0.04 0.01 to 0.04 0.01 to 0.04 0.005 to 0.04 0.01 to 0.04 0.01 to 0.04 occur when both types of substances are present in the bath, and in particular when they are in theirs optimal concentrations can be used. In general, it is desirable to use mixtures of two or more to use more of these sulphurous shine generators, e.g. B. o-Benzoylsulfimid and p-Toluenesulfonamid and Allyl sulfonic acid and benzenesulfonamide.

Table II

0.01 to 0.04 0.005 to 0.04 0.003 to 0.03 0.003 to 0.03 0.002 to 0.02 0.003 to 0.02 0.003 to 0.02 0.003 to 0.02 0.003 to 0.02

The substances in Table II explain the class of compounds that interact with the substances of Table I can be used in practicing the invention.

Some of them are used as brighteners in nickel plating baths has been described, e.g. In the United States, Applicants' patents 2,191,813 and 2,466,677. In the practice of the present invention, there results an interaction of which its precise nature is unknown in the cathode film on which the compounds shown in Table I and the organic sulfur-containing ones Glossers are involved and that produces the unusual and extremely valuable results,

1.
2.
3.
4th
5.
6th
7th

9.
10.

11.

12th
13th
14th

15th
16.

17th

18th
19th

20th
21.

22nd
23
24
25th
26th
27

Sulfur-containing shiners

Optimal concentration in g / l

Benzenesulfonamide

Toluenesulfonamide (o- and p-)

o-benzoyl sulfimide

N-benzoylbenzenesulfonimide

p-toluenesulfonchloramide

p-bromobenzenesulfonamide .... 6-chloro-o-benzoylsulfimide ... m-aldehyde benzenesulfonamide

SO ₂ NH ₂

CHO

Sulfomethylbenzenesulfonamide benzenesulfonamide-m-carboxylamide

7-aldehyde-o-benzoyl sulfimide

NH

SO ₂

COO

N-acetylbenzenesulfonimide ... Methoxybenzenesulfonamide .. hydroxymethylbenzenesulfone

amide

Vinyl sulfonamide

Allylsulfonamide

Benzenesulfonic acids (mono-, di-

and tri-)

p-bromobenzenesulfonic acid

Benzaldehyde sulfonic acids

(c, m, p)

Diphenylsulfonic acid ... naphthalenesulfonic acids

(mono-, di- and tri-) .... benzenesulfohydroxic acid ...

p-chlorobenzenesulfonic acid

Diphenyl sulfonic acid

m-Diphenylbenzenesulfonic acid 2-chloro-5-sulfobenzaldehyde

m-benzene disulfonamide

Allyl sulfonic acid

0.1 to 3 0.1 to 2 0.1 to 2 0.1 to 1 0.1 to 1 0.1 to 1 0.1 to 1 0.1 to 1

0.1 to 6

0.1 to 3 0.1 to 3

0.1 to 2 0.1 to 1

0.1 to 2 4 to 12 4 to 12

1 to 15

3 to 6

2 to 6 Ibis 8

1 to 8 1 to 5 1 to 15 1 to 5 1 to 4 1 to 5 0.5 to 1

4 to 12

These sulfur-containing gloss agents can be in their acid form or in the form of salts, e.g. B. the nickel, Sodium, potassium or other salts can be used.

obtained in accordance with the present invention. 65 are particularly favorable to use for execution In this context, it should be noted that the invention includes compounds No. 1, 2, 3; 18, 1.9, 21 Use only the substances or compounds in and 28 of Table II, the latter in particular in the form Table I or the use of their nickel salts alone. Where the term sulfonic acid in. The organic sulfur-containing gloss agent is not used in any way description and claims are indicate the vastly improved results, including their salts.

The compounds of Table II, when used alone, produce quite satisfactory results shiny deposits on metal, polished with leather, e.g. B. brass surfaces. However, they do not achieve - at least not in the usual way - · the same results on sanded with 180 grit sandpaper Steel or on matted (but not fired) copper plates from 0.0075 to 0.0125 mm Starch, but in these cases results in coatings of a somewhat dull and gray appearance. The connections of Table I give a precipitate of one in the usual manner when used alone species other than that produced by the compounds of Table II. The one with the connections Precipitation generated in Table I is fine-grained and cloudy and at low concentrations are quite dark, brittle, slightly discolored and have poor adhesive properties at higher concentrations. However, when the two different types of compounds given in Tables I and II are put together are used in the bathrooms, as stated above, shiny, mirror-like, well-adhering and ductile deposits even on matt surfaces.

Only relatively small amounts of the compounds of Table I or mixtures of them are necessary in order to to achieve the above results. Generally, amounts are on the order of about 0.003 to about 0.04 g / l of any of the compounds or mixtures of them extremely effective. Even in the case of the less For effective compounds it is seldom necessary to go beyond about 0.06 to 0.08 g / L. As a general Typically, the optimal concentration of the compounds is on the order of about 0.003 to about 0.04 g / l.

The compounds of Table II are also used in small amounts in conjunction with the compounds of Table I, in that amounts on the order of about 0.1 or 2 or 3 g / l usually have the desired effect. However, larger amounts up to saturation can be used. In general, it is not necessary to over 0.5 ° / ₀ go out.

The optimal concentration of the compounds of Tables I and II can be quickly determined for each Application by simple sample taking into account the particular nickel bath used, its Temperature, its pn concentration and other properties to be determined.

The aqueous nickel plating baths can be of various types be, but they always have a sour character. The preferred baths are matte nickel baths that are capable are to produce thick, well adhered ductile deposits, those of the Watts type or a variation of which are particularly desirable. The nickel salts can be nickel chloride, nickel sulfate, nickel fluoroborate, Nickel sulfamate and other nickel salts or mixtures of two or more of these nickel salts, and preferably in conjunction with buffer substances, e.g. B. boric acid. The use of botic acid in the Bath is preferred because it is generally the best cathode film buffer. Other buffers of sour However, characters can be used, e.g. B. formic acid, citric acid, fluoroboric acid (borofluoric acid), and these buffering agents can be used either in place of or in conjunction with boric acid. For best results, the concentration of boric acid or its equivalent should be above 30 g / l especially in baths that are used at a slightly elevated temperature. The bathrooms can also be different complementary substances, e.g. B. Od scar prevention substances. Like. Contain.

The baths can be operated at temperatures ranging from about room temperature to near boiling temperature; in general, however, the preferred temperature is on the order of about 40 to 65 ° C. In general, the baths can be operated at pn values ranging from about 2 to about 5.5; Usually, however, the pn values range from 2.5 to 4.8. The ranges for cathodic current density are quite variable; a range from about 0.5 to a few tens, namely 21.5 Amp / dm ^2, is applicable, the optimum being dependent on the bath agitation (the agitator), the temperature and the concentration and type of nickel salts used in the bath depends. A good work area is from about 2 to about 8.5 amps / dm ² .

Preferred embodiments of the bath compositions are listed in Table III.

Table III

bath NiSO ₄ -OH ₂ O NiCl ₂ • 6H ₂ O Ni (BF ₄ ), H ₈ BO ₈ No. g / i g / l g / l eat 1. 300 40 2. 100 to 300 0 to saturation 3. 100 to 200 200 to 100 40 4th 300 60 40 5. 225 50 to 75 40

Table III (continued) Bathroom no. temperature 1 to 5.2 Current density Additives ⁰ C Amp./dm ² g / l 1. 24 to 71 1 to 11 N-Benzyl 1-4 methylquinoline chloride 0.3 4 to 5 Benzenesulfonamide 2 o-benzoyl sulfimide 2 2. 24 to 71 3 to 4.5 1 to 22 N-Benzyl-S-methylisoquinoline chloride .. 0.02 Naphthalene sulfonic acids 3 to 6 3. 38 to 60 4.3 to 6.5 N-Benzyl - ^ - chloropyridine chloride 0.02 to 0.06 2.5 to 4.8 o-Benzoyl sulfimide 1 p-toluenesulfonamide 1 4th 21 to 71 4.3 to 6.5 N-4-nitrobenzyl pyridine chloride 0.01 to 0.02 2.5 to 4.8 p-Toluenesulfonamide 1 to 2 o-Benzoyl sulfimide 1 to 3 5. 21 to 71 IT 4.3 to 6.5 N-Benzyl-1-methylquinoline chloride 0.01 to 0.03 Benzenesulfonamide 2 o-benzoyl sulfimide 2

It should be noted that from time to time it is necessary to refill the bath to avoid losses as a result of Processes at the cathode as a result of "pulling out" and as a result of other causes to replace the concentrations of the added connections in operational conditions.

Claims (7)

Patent claims 1. Bath for the electroplating of shiny nickel, characterized in that it consists of an aqueous acidic solution of a nickel salt containing 0.003 to 0.08 g / l of a soluble compound of the general formula contains (R ₂ ), - Ar - CHZ - NX - (R ₁ ) _Λ a quinoline or iso corresponding nucleus where NX is the remainder
quinoline nucleus or which contains a methyl or ethyl substitution group on a core carbon atom, while A is an anion of a water-soluble acid, R _{1 is} a halogen atom, R _{2 is} a halogen atom or a nitrogen, methyl or fluoromethyl group, Ar is a benzene or naphthalene radical, Z is hydrogen, methyl or ethyl, and χ and y is zero, 1 or 2, and that the solution also contains up to 1.5 ° / ₀ of an organic sulfonamide, sulfonimide, or a sulfonic acid. 2. Bath according to claim 1, in which in the compound of the general formula indicated R _{1 is} chlorine or bromine, R _{2 is} chlorine, bromine or a nitrogen group, χ and y zero or 1, Ar is a benzene radical, A is chlorine or bromine and Z is a Are hydrogen atom. 3. Bath according to claim 1, characterized in that in the characterized general formula A is chlorine or bromine, R _{2 is} a nitrogen group, χ is zero and y is 1. 4. Bath according to claim 1, characterized in that the compound of the specified general Formula has the following structural formula CH ₉ -N wherein R ₁ , A and χ have the meanings given to them in claim 1. 5. Bath according to claim 1, characterized in that the compound of the characterized general Formula has the following structural formula -CH ₉ wherein R ₁ , A and χ have the meanings given to them in claim 1. 6. Bath according to claim 1 to 5, characterized in that the sulfonamide, sulfonimide or sulfonic acid are present in a proportion of not more than 0.5 ° / ₀ . 7. Bath according to claim 1 to 6, characterized in that the nickel salt is nickel chloride, nickel sulfate or nickel fluoroborate or a mixture of some of these salts. - Considered publications:
German patent application U 623 VI / 48 a;
Zeitschrift für Elektrochemie, Vol. 46, 1940, pp. 71 to 82. 1 709 50W53 5.57