DE1621116B2 - Bright nickel bath - Google Patents

Description

C = CH

K)

where a is an integer from 0 to 3, R * is an alkyl radical having 1 to 4 carbon atoms, r> and

20th

stands for pyridine or quinoline, characterized in that the bath as first primary brightener 0.002 g / l to 0.5 g / l butynediol or a hydroxyethoxylated butynediol and as the second primary brightener, 0.002 g / L to 0.1 g / L of a compound having a cation

R *

contains where

- CH ₇ -A

represents pyridine, quinoline or isoquinoline, a represents 0 to 5, A represents a radical of the formula

X X

-C = C-H

-C = C-H

stands, where X is an active halogen, and R * is alkyl, hydroxyalkyl, halogen, alkoxy, carboxyl, Carbalkoxy, acetyl, benzyl, sulfo, carboxamido or cyano

2. Bath according to claim 1, characterized in that the first primary brightener consists of 1,4-di- (betahydroxyethoxy) -2-butyne consists.

3. Bath according to claim 1, characterized in that the first primary brightener consists of l- (beta-hydroxyethoxy) -4-hydroxy-2-butyne consists.

4. Bath according to claims 1-3, characterized in that the second primary brightening agent a cation of the formula

⁺ -CH ₂ -C = CH

where R * is alkyl or hydroxyalkyl and a is 0 to 5.
5. Bath according to claims 1-3, characterized in that the second primary brightener is a cation of the formula

CH,

CH,

N-CH,

-CH, -C = CH

having.

6. Bath according to claims 1 to 3, characterized in that the second primary brightening agent a cation of the formula

CH ₂ -CX = CHX

wherein a is 0-3.

7. Bath according to claim 6, characterized in that the second primary brightening agent is a cation of the formula

O-

CH _? - CX = CHX

having.

From an older proposal (DE-PS 14 70 061) is a Bright nickel bath known, which in addition to a usual 3> secondary brightening agent as a primary brightening agent Contains pyridinium or quinolinium compound in which the nitrogen atom is replaced by a 23-dichloropropene radical is quaternized.

It has now been found that baths with higher, faster gloss development are obtained when in addition to the primary brightener mentioned, they also contain a further primary brightener.

The invention therefore relates to a bright nickel bath which, as the primary brightening agent, is a pyridinium or a quinolinium compound with a cation of the formula

Cl Cl

-CH ₂ -C = CH

wherein a is an integer from 0 to 3, R * is an alkyl radical having 1 to 4 carbon atoms and

stands for pyridine or quinoline, which is characterized in that the bath is the first primary brightener 0.002 g / l to 0.5 g / l butynediol or a hydroxyethoxylated butynediol and the second primary brightener 0.002 g / l to 0.1 g / l of a compound having a cation

-CH ₇ -A

contains where

represents pyridine, quinoline or isoquinoline, a represents 0 to 5 A is a radical of the formula

X X

-C = C-H

Table III

Sulphamate-type baths

Nickel sulfamate

Nickel chloride

Boric acid

temperature

PH value

or -C = C-H, where X is an active halogen, and R * for alkyl, hydroxyalkyl, halogen, alkoxy, carboxyl, carbalkoxy, acetyl, benzyl, sulfo, carboxamido or cyano stands.

Further refinements of the bath according to the invention are described in the subclaims.

From US-PS 30 06 822 similar baths as from DE-PS 14 70 061 are known, the primary Brighteners contain a similar pyridinium compound, but which is sulfonated in the pyridinium nucleus. These In addition, unlike the baths according to the invention, baths contain only one primary brightener. You own therefore not the advantages of the baths according to the invention.

From US-PS 30 54 733 baths are known, in addition to pyridinium compounds in which the nitrogen atom is quaternized by an acetylenic radical, as well as other sulfonated alkynyl compounds may contain. In contrast, the alkynyl compounds used according to the invention are not sulfonated and more simply structured.

Metals that can be nickel-plated by the baths according to the invention are, for example, copper alloys, Ferrous metals, zinc and zinc alloys. The metal to be nickel-plated is preferably used first a coating of copper or semi-bright nickel is applied before a bath according to the invention is applied will.

The first and second primary brighteners can be used in a wide variety of nickel baths, For which some examples are given below:

330 to 600 g / l
15 to 60 g / l
35 to 55 g / l
30 to 55 ⁰ C
3.5 to 5.0

(electrometric

measured)

Other baths are those containing nickel fluorate plus nickel chloride and nickel sulfamate plus nickel chloride. In the baths given in the tables above, the nickel chloride is used as the hexahydrate of the formula NiCb · 6 H ₂ O and the nickel sulfate is used as the hexahydrate of the formula NiSO ₄ · 7 H ₂ O.

For example, temperatures of 30 to 65 ^° C., electrometrically measured pH values of 3.5 to 5, preferably 3.8 to 4.5, and cathode current densities of 1 to 10 A / dm ² can be used as electroplating conditions for the baths according to the invention. Typical preferred current densities of the baths in Table I are 4 to 6 A / dm ² . Agitation is preferred during electroplating.

It is a particularly advantageous feature of the baths of the invention that they are excellent Results are obtained when the bath is composed as a Watts-type bath.

In the following Table IV examples of butyne compounds according to the invention are given can be used as the first primary brightener.

Table IV

2-butyne-1,4-diol

1,4-di- (j3-hydroxyethoxy) -2-butyne

1- (j3-Hydroxyethoxy) -2-butyn-4-ol

3-butyne-1,2-diol

1,2-di- (j3-hydroxyethoxy) -3-butyne

Table I.

Baths of the Watts type

Nickel sulfate

Nickel chloride

Boric acid

temperature

PH value

200 to 400 g / l
30 to 75 g / l
30 to 50 g / l
30 to 65 ° C
3.5 to 5.0

(electrometric

measured)

Table II

Baths with a lot of chloride

Nickel chloride

Nickel sulfate

Boric acid

temperature

PH value

150 to 300 g / l
40 to 225 g / l
30 to 50 g / l
30 to 65 ° C
3.5 to 5.0

(electrometric

measured)

The first primary brightener is in those of the present invention Baths in an amount from 0.002 to 0.5 g / l, preferably from 0.005 to 0.10 g / l, in particular from 0.01 to 0.05 g / l, present.

The second primary brightener can be represented by the following formula

where X- stands for an anion that is soluble in the bath and compatible with the bath, for example bromine, chloride, Iodide, fluoride, acetate, sulfate, methyl sulfate, ethyl sulfate, citrate, chloroacetate, perchlorate, stands. Preferably means X- halides including fluoride, chloride,

Bromide and iodide. These compounds can be easily implemented through the implementation

+ A-C-Χ

getting produced. If A

X X

Ii Il

-C = C-H

and X stands for bromine, then the above compound can also by bromine addition to a corresponding acetylenic compound can be produced.

Examples of typical acetylenic heterocyclic compounds are given in Table V below compiled.

Table V

2,6-dimethyl-N-propargylpyridinium bromide 3,5-dimethyl-N-propargylpyridinium bromide 2,4-dimethyl-N-propargylpyridinium bromide 3,4-dimethyl-N-propargylpyridinium bromide 2,5-dimethyl-N-propargylpyridinium bromide

S-ethyl ^ -methyl-N-propargylpyridinium bromide 2,4,6-trimethyl-N-propargylpyridinium bromide 2-j9-hydroxyethyl-N-propargylpyridinium bromide 2-γ-hydroxypropyl-N-propargylpyridinium bromide

3-hydroxymethyl-N-propargylpyridinium bromide 2-methyl-6-y-hydroxypropyl-N-propargylpyridinium bromide

2-ethyl-4,6-di- (| 9-hydroxyethyl) -N-propargylpyridinium bromide

2,4,6-tri- (hydroxymethyl) -N-propargylpyridinium bromide

The preferred compounds are 2,4,6-trimethyl-N-propargylpyridinium bromide and 2,4-dimethyl-N-propargylpyridinium bromide.

Examples of typical dihalogenated ethylenic heterocyclic compounds are as follows Table VI compiled:

Table VI

N- (2,3-dibromopropenyl) -2,4,6-trimethylpyridinium bromide

N- (2,3-dibromopropenyl) -3,5-dimethylpyridinium bromide

N- (2,3-dibromopropenyl) -4-isopropylpyridinium bromide

N- (2,3-dibromopropenyl) -2,6-dimethylpyridinium bromide

N- (2,3-dibromopropenyl) -2-aminopyridinium bromide

N- (2,3-dibromopropenyl) -3-methylpyridinium bromide

N- (2,3-dibromopropenyl) -3-cyanopyridinium bromide

N- (2,3-dibromopropenyl) -4-ethylpyridinium bromide

N- (2,3-dibromopropenyl) -4-methylpyridinium bromide
N- (2,3-Dibromopropenyl) -2,4-dimethylpyridinium bromide N- (2,3-Dibromopropenyl) -2-chloropyridinium bromide

N- (2,3-dibromopropenyl) -2-ethylpyridinium bromide

N- (2,3-dibromopropenyl) -2-j9-hydroxyethylpyridinium bromide N- (2,3-Dibromopropenyl) -2-y-hydroxypropylpyridinium bromide N- (2,3-Dibromopropenyl) -2-methylquinolinium bromide

N- (2,3-Dibromopropenyl) -2-p-methoxybenzyl-aminopyridinium bromide

N- (2,3-Dibromopropenyl) -isoquinolinium bromide jo N- (2,3-Dibromopropenyl) -3-sulfopyridinium-

bromide (Na-Salz) N- (2,3-dibromopropenyl) -3-hydroxymethylpyridinium bromide N- (2,3-dibromopropenyl) -2-methylpyridinium bromide

N- (2,3-dibromopropenyl) -3,4-dimethylpyridinium bromide N- (2,3-Dibromopropenyl) -2,5-dimethylpyridinium bromide N- (2,3-Dibromopropenyl) -3-ethyl-4-methylpyridinium bromide N- (2,3-dibromopropenyl) -4-methylquinolinium bromide

N- (2,3-dibromopropenyl) -2-aldoximpyridinium bromide

N- (2,3-Dibromopropenyl) -2,6-diaminopyridinium bromide, N- (2,3-Dichloropropenyl) pyridinium chloride N- (2,3-dichloropropenyl) pyridinium iodide, N- (2,3-dichloropropenyl) -3,4-dimethylpyridinium iodide N- (2,3-dichloropropenyl) -4-methylpyridinium iodide

N- (2,3-dichloropropenyl) -2-methylpyridinium iodide

N- (2,3-dichloropropenyl) -3,5-dimethylpyridinium iodide

The second primary brightener is in the bath in an amount of 0.002 to 0.01 g / l, preferably 0.002 to 0.05 g / l, and especially 0.01 g / l, is present.

Preferably the total amount of the primary brighteners is, i. H. so the sum of the amount of first and second primary brighteners, 0.004 to 0.6 g / l, especially 0.007 to 0.15 g / l, for example 0.02 g / l.

The preferred baths according to the invention contain in typical amounts from 1 to 75 g / l, preferably from

1 to 20 g / l, secondary gloss agents, such as. B. sulfur / oxygen compounds, for which saccharin and that Sodium salt of benzene monosulfonic acid are typical. The latter secondary brightener can be due to its higher zinc tolerance, d. H. its ability to allow higher concentrations of zinc in the bath, be preferred. In baths with a high chloride content, it may be preferable to use saccharin or the sodium salt of to use sulfonated dibenzothiophene dioxide. Naphthalene sulfonates were found to be of low resp. no effectiveness in the method according to the invention.

Secondary auxiliary gloss agents, typically in an amount of 2 to 30 g / l, preferably 2 to 10 g / l, for example 4 g / l, include unsaturated hydrocarbon sulfates, such as the sodium salt of 3-chloro-2-butenesulfonic acid, the sodium salt of 2-propene-l-sulfonic acid, the sodium salt of l-phenylethene-2-sulfonic acid, the sodium salt of 3-methyl-1-buten-3-ol-1-sulfonic acid, the sodium salt of 3-hydroxy-1-propene-1-sulfonic acid.

The plating with nickel by the bath according to the invention allows the achievement of a shiny or brilliant, smooth and highly leveled bright nickel deposit in a wide range of current densities. In special cases, for example when using saccharin as a secondary brightener, the coverage in the area of low current density is significantly increased. Generally there is an improvement with regard to the rate of gloss formation or the degree of gloss formation and the elimination of formation from semi-gloss to matt deposits in areas of low current density.

The invention is illustrated by the following examples, all parts being parts by weight, unless otherwise stated.

In these examples, the Watts bath included:

NiSO ₄ · 7 H ₂ O
NiCl ₂ · _{6H 2} O
Boric acid

300 g / l
60 g / l
45 g / l

the high chloride bath

NiSO ₄ · 7 H ₂ O
NiCl ₂ · _{6H 2} O
Boric acid

the sulfamate bath

Nickel sulfamate
NiCl ₂ · _{6H 2} O
Boric acid

225 g / l
225 g / l
45 g / l and

375 g / l
45 g / l
45 g / l

D '

E '

N- (2-propynyl) -2,4,6-trimethyl-

pyridinium bromide

N, N '- [bis- (2-propynyl)] -

4,4'-dipyridinium bromide

N, N '- [bis- (2,3-dichloropropenyl)] -

4,4'-dipyridinium dichloride

IO

15 The secondary brighteners used were as follows:

Table IX

A "saccharine (sodium salt)

B "sodium salt of benzene monosulphonic acid C" disodium salt of m-benzene disulphone

acid

D "sodium salt of p-toluenesulfonic acid E "Sulphonated dibenzothiophene dioxide

(Na-SaIz)

20th

25th

30 The secondary auxiliary gloss agents used were as follows:

Table X

A '"sodium salt of 3-chloro-2-butene

sulfonic acid

B '"sodium salt of 2-propene-1-sulfonic acid C "sodium salt of 1-phenylethene

2-sulfonic acid

The anti-pore surfactants used were as follows:

Table XI

A "" Sodium Lauryl Sulphate
B "" Sodium salt of di (n-hexyl) sulfosuccinate

The acetylenic primary brighteners used were as follows:

Table VII

A 2-butyne-1,4-diol

B 1,4-di- (j3-hydroxyethoxy) -2-butyne

The N-heterocyclic primary brighteners used were as follows:

Table VIII

A 'N- (2,3-dichloropropenyl) pyridinium

chloride
B 'N- (2,3-dibromopropenyl) -

2,4,6-trimethylpyridinium bromide

The baths used were Watts baths in Examples 1 to 8, baths with a high chloride content in Examples 9 to 11 and sulfamate baths in Examples 12 and 13. The additives were added in the specified amount. All experiments were performed using highly polished brass cathode with a cathode current density from an average of 5 A / dm ² at a temperature of 60 ⁰ C in the Watts bath and Sulfamatbädern and a cathode current density from an average of 6 A / dm ² at a temperature of 65 ° C carried out in the baths with a high concentration of chloride. The baths were stirred. The baths of Examples 1-8 and 12 and 13 contained 0.2 g / l of additive B "". In Examples 9-12 the baths contained 0.5 g / l of additive A "". The nickel-plating time was 30 minutes To determine the degree of leveling or smoothing, the brass cathodes were scratched with a single line of sandpaper prior to nickel-plating.

Examples

additions

Quantities in g / l

A. 0.10 909 510/12 A ' 0.010 A " 4.0 A '" 4.0

continuation

Examples

additions

Quantities in g / l

B. 0.05 A ' 0.01 A " 4.0 A '" 4.0 B. 0.05 A ' 0.01 A " 4.0 B '" 3.0 B. 0.05 B ' 0.01 A " 4.0 A '" 4.0 B. 0.05 C. 0.01 A " 4.0 A '" 4.0 B. 0.05 D ' 0.002 A " 4.0 A '" 4.0 B. 0.05 E ' 0.005 A " 4.0 A "' 4.0 B. 0.05 A ' 0.01 E " 4.0 A '" 3.2

Examples

additions

Quantities in g / l

B. 0.05 A ' 0.01 A " 4.0 A '" 4.0 B. 0.05 A ' 0.01 A " 4.0 B '" 3.0 B. 0.05 A ' 0.01 E " 4.0 A "' 4.0 B. 0.05 A ' 0.01 A '' 4.0 A '" 4.0 B. 0.05 A ' 0.01 A " 4.0 B '" 3.0

In all cases it has been observed that the nickel coating is characterized by a high degree of leveling, Flexibility or suppleness and speed of gloss formation were excellent. In the case of example 2, In the preferred embodiment, the combination of primary brighteners gave an extremely high one Leveling or smoothing, pliability or suppleness and gloss formation speed as well as a substantial improvement of the coverage in the areas of low current density. The better cover in areas of low current density is particularly excellent when saccharin is used as a secondary brightener is used.

Claims (1)

Patent claims: 1. Bright nickel bath, which is a pyridinium or quinolinium compound as the primary brightening agent "> with a cation of the formula R _u * -CH ₂ Cl Cl