DE1063003B - Process for the electrolytic production of high-gloss nickel coatings - Google Patents

Description

GERMAN

kl. 48 a

(TERNAT. KL. C 23 b

PATENT OFFICE

£ 25

ANH ELOETAC:

NOTICE DEBANHELDUNC OND ISSUE OF ADSLEC WRITING:

H 19752 VI / 48 a

MARCH 24, 1954 AUGUST 6, 1 «> 59

The additional patent 931 623 relates to a process for the electrolytic production of high-gloss nickel coatings, after an aqueous, acidic nickel electrolyte, a low content of polyunsaturated alcohols, in particular triunsaturated alcohols is added together with m-benzenedisulfonic acid alkali.

It has been shown that to achieve a high-gloss, dense nickel deposit, other Sulfur-oxygen compounds can be used advantageously. to

According to the invention, nickel is obtained by electrolysis from an acidic aqueous solution with the addition of three times unsaturated alcohols together with about 0.25 to 80 g / l of a water-soluble sulfoxide of that group put down, those from unsaturated aliphatic sulfonic acids, dinuclear aromatic sulfonic acids, heterocyclic Sulphonic acids, mononuclear aromatic sulphinic acids, alkali, ammonium, magnesium and nickel salts of these acids and of mononuclear aromatic sulfonamides and imides. ao

Although in principle any sulfoxides belonging to the groups mentioned can be used in accordance with the invention, Table I summarizes the sulfoxides which have a particularly favorable influence on the nature of the nickel content. The concentrations given in Table I gave a good effect when the compound in question was added together with 0.1 g / l butynediol to a bath containing 330 g / l nickel sulfate, 45 g / l nickel chloride and 37.5 g / l boric acid contained a pn value of 3.5 at 50 ° and at 4.3 A / dm ¹ mean current density and was kept in motion with compressed air.

Process for the electrolytic production of high-gloss nickel coatings

Addition to additional patent 931 623

Applicant:

Dr. W. Kampschulte & Cie. _f Solingen, Schützenstr. 66-70

Claimed priority: V. St. v. America March 24, 1953

Otto Kardos, Matawan, N. J. (V. St. A.) has been named as the inventor

Panel I.

Benzylsulfonamide C ₄ H ₄ CH ₁ SO ₁ NH ₁ 2 g / l

Anilinesulfonic acid C _{4 HjSO 1} NHOH .. 2 g / l

Ν, Ν-dimethylparatoluenesulfonamide

CH ₃ C ₄ H ₄ SO ₁ N (CH) ₁

N.N-dicarboxylethylbenzenesulfonamide

O, H ₄ SO ₁ N (C ₁ H ₄ COOH) ₁

(4) Dinuclear aromatic sulfonic acids and alkali,

(1) Unsaturated aliphatic sulfonic acids and alkali, ammonium, magnesium and nickel salts of these acids:

Ammonium, magnesium and nickel salts of these acids: _ “. ,

2-N aphthahn monosulfonic acid sodium vinyl sulfonate

H ₁ C = CHSO ₃ Na 2 to 4 g / l

Sodium allyl sulfonate

H ₁ C = CHCH ₁ SO ₃ Na 2 to 4 g / l

(2) Mononuclear aromatic sulfinic acids and alkali, ammonium, magnesium and nickel salts of these acids:

Sodium benzene sulphate C ₄ H ₄ SO ₁ Na ..

C ₁₀ H ₇ SO ₃ H
1,5- or 2,7-naphthalenedisulfonic acid

C ₁₀ H ₄ (SO ₃ H) ₁ 1.5 to 3

1,5- or 2,7-naphthalenedisulfonic acid

Nickel salt C ₁₀ Hg (SO ₃ ) Ni 1.5 to 3

Sodium paratoluenesulfinate
CH ₁ C ₁ H ₄ SO ₁ Na

0.4 g / l 0.4 g / l

45

(3) Mononuclear aromatic sulfonamides and imides: Benzenesulfonamide 0, H ₄ SO ₁ NH ₁ .... 2 g / l

Paratoluenesulfonamide
CH ₁ C ₄ H ₄ SO ₁ NH ₁ ...

Orthobenzoic acid sulfide
0, H ₄ CON HSO ₁

2 g of naphthalene trisulfonic acid

C ₁₀ H ₄ (SO ₃ H) ₃

Diphenyl-pp'-disulfonic acid

HSOjC ₄ H ₄ -C ₄ H ₄ SO ₃ H up to

Saturation (less than 2 gl)
2-Napthol-3,6-disulfonic acid

HOC ₁₀ H ₄ (SO ₃ H) ₁

2-naphthol-3,6-disulfonic acid sodium

salt HOC ₁₀ H ₄ (SO ₃ Na) ₁

1-naphthylamine-3,6,8-trisulfuric acid

H ₁ NC ₁₀ H ₁ (SO ₁ H) ₁

1 to 40

g / l gß

1.5 g / l

3 gß gß gß

4 g / l 4 g

4 g / l «n sw 354

(5) Heterocyclic sulfonic acids and alkali, ammonium, magnesium and nickel salts of these acids:

Thiophenesulfonic acid C ₄ H, S · SO, H .. sodium thiophenesulfonate

C ₄ H ₁ S SO ₃ Na

2- (4-pyridyl) ethylsulfonic acid
C ₁ H ₄ N-CH ₁ CHjSO ₃ H

g / l gß

g / l

The concentrations given in Table I result in high-gloss nickel deposits, but they do not represent in any case represents the optimal concentration. The free sulfonic acids as well as the alkali, ammonium, magnesium and nickel salts of these acids are fully included in all examples of the process of the invention equivalent to each other.

Table II shows the results obtained with a bent cathode in a normal electrolytic bath, which contains sulfates, chlorides and boric acid, has a pH value of 3.5 and is stirred with compressed air will.

TafeTlI

kept to a milky precipitate to avoid low current density, especially if the concentration of butynediol is very low, i. H. is only about 0.1 g / l. The concentration range is at 0.2 g of 1-butynediol naphthalenetrisulphonic acid, on the other hand, goes very far.

If a connection of Table I alone, i.e. H. without the addition of an acetylene compound, is used only matt or semi-matt, whitish nickel coatings ίο achieve. Only together with a polyunsaturated one Alcohol, the sulfoxides of Table I give a high-gloss nickel coating; the smoothing effect on the metal surface only occurs if it is present an unsaturated alcohol. Table III shows the Abbott surface roughness values (RMS) before and after treatment in a normal electrolytic nickel salt bath under the above conditions with a thickness of the nickel coating of 0.025 mm.

current Butyne 1,3,6-naphthalenetrisulfonic acid Sodium salt in g / l density diol milky Tem A / cm « eA evenly Precipitation,
particularly temperature 1.4 0.1 matter high gloss at lower
Current density • c 4.3 0.1 shine 2 4th 30th 1.4 0.1 2 to 6 30th 1.4 0.2 1 to 2 4 to 8 50 4.3 0.1 1 to 80 - 50 4.3 0.2 1 to 40 - 50 6.5 0.1 1 to 80 50 6.5 0.1 2 to 4 50 6.5 0.1 1 1 to 2 4th 60 - 1 2 70 -

»5 blackboard Butynediol III quality values
after 28 Naphthalene-
trisulfonate 4.0 g / I RMS rough
before electroplating 27 g / l 6 to 7 28 6th 30 2.0 28 10 2.0 0.6 25th 8th 4.0 1.2 22nd 6 to 7 0.1 28 0.2 28 0.2 26th

If the current density is low and / or the bath temperature is high, the concentration of naphthalenetrisulfonic acid must or the sulfoxide used is quite low As already mentioned, the permissible concentration range is the additives mentioned in Table I are quite large; but there is one of the concentration of the unsaturated Alcohol-dependent lowest concentration of the sulfur-oxygen compound, below which a high gloss cannot be achieved. Table IV gives examples of the composition an electrolytic bath according to the invention, which has a pn value of 3.5, at a current density of 4.3 A / dm * and operated with air circulation.

Plate IV

Composition of the electrolytic bath in g / l

1 ² I. 3 Bathroom no. 5 ⁶ I. 7th 24ObU 330 330 I.
330 4th 240 Nickel sulfate NiSO ₄ 7 H ₁ O .. 30 to 45 330 0 to 37.5 0 to 37.5 30th Nickel chloride NiCl ₁ 6 H ₁ O .. __ Nickel formate - - - --- ■ - 45 Ni (OOCH) ₁ ^ H ₁ O _ - - 210 - Nicke Muoborate Ni (BF ₄ ), - - - 225 - - Nickel sulfamate Ni (O ₁ SNH ₁ ), 29.5 - - Sodium chloride NaCl - - Sodium bromide NaBr 30 to 37.5 37.5 0 to 37.5 51.5 30th 30th 37.5 Boric acid H ₁ BO ₃ 0.1 to 0.2 0.2 0.1 0 to 37.5 0.2 0.2 0.8 2-butyne-1 _f 4-diol, 2.0 to 8.0 4.0 4.0 0.1 2.0 2.0 2.0 1,3,6-naphthalene trisulfonate .. 25 to 60 50 50 4.0 50 50 80 Temperature, ⁰ C 50

The solution used for electrolysis according to the invention should be acidic; for example, is the cheapest PH value of a bath containing 0.1 g / l butynediol and 1,3,6-naphthalene trisulfonate and is operated at 50 "C with a current density of 4.3 A / dm *, between 3.0 and 5.0. With a pn value of 2.5, the concentration must be 65 tion of the butynediol can be increased to about 0.2 to 0.3 g / l in order to achieve a precipitate with the highest gloss.

In order to obtain completely pore-free nickel coatings,

it is advisable to keep well-filtered solutions in the bathroom in strong motion by means of compressed air, or other-

70 on the other hand, with less stirring, the bath

dignified wetting agent, such as ζ. B. sodium lauryl sulfate, to be added in an amount up to 0.25 g / l.

Claims (2)

Patent claims. 1. A process for the electrolytic production of high-gloss nickel coatings according to additional patent 931623, characterized in that about 0.25 to 80 g / l of another sulfur-oxygen compound is added to the nickel bath in addition to triunsaturated alcohols instead of m-benzenedisulfonic acid alkali . 2. The method according to claim 1, characterized in that a sulfur-oxygen compound unsaturated aliphatic sulfonic acid, a dinuclear aromatic sulfonic acid, a heterocyclic sulfonic acid, a mononuclear aromatic sulfinic acid or an alkali, ammonium, magnesium or nickel salt of the acids mentioned or a mononuclear aromatic sulfonamide or sulfonimide is added. Considered publications:
German patent specifications No. 845 587,848 890,863 159, 100. Journal of Electrochemistry, 46 (1940). P. 79.