DE2224783A1 - MEANS FOR IMPROVING COATING STRIPS AND THEIR APPLICATION - Google Patents

Description

Means for improving plating baths and their

use

The invention relates to the electrodeposition of highly polished nickel transmitters from acidic electrodeposition baths and in particular compounds and mixtures thereof which are added to such baths for the deposition of a to influence shiny and even nickel plating.

It is known that it is advantageous to galvanic nickel-plating baths To add small amounts of certain organic compounds, which the gloss and the evenness improve the coating. A glossy coating is one that gives a good SLR while a uniform coating means that the irregularities in the surface of workpieces that arise from the Production by casting, pressing, cutting and grinding results or also fine cracks and grooves that result from the treatment left behind with abrasives, filled in and in this way at least for the most part on the hitherto rough surface can be eliminated. The fact whether a new chemical is a smoothing out ven surfaces the electroplating effects and / or to a high-gloss finish Coating cannot be predicted with certainty from its chemical structure.

309808/1374

BATH ORIGINAL

Known chemicals that are suitable for said Zv / eck are unsaturated 'compounds, in particular compounds of acetylene. Since these acetylene compounds are in aqueous Plating baths need to be dissolved, water solubility is one of the desirable properties of these substances.

For this reason, these compounds generally have one or more groups which favor solubility in water, such as, for. B. hydroxyl, alkoxy, carboxy or sulphoxy groups. Although these groups are essentially intended to promote water solubility, their type and position on the molecule can also influence the properties of the resulting nickel plating solutions »

Acetylene alcohols were the first acetylene compounds to use one has proposed for the said Zv / eck.

It has now been found that the mixture obtained by reacting acetylenediol with less than the equimolar amount of an ethylene oxide or a corresponding oxirane compound is a beneficial new agent which is extremely useful as an additive to acidic nickel plating baths is advantageous.

The Fac-binann will very much welcome the fact that such an element consists essentially of unreacted Ausgarjftfjijj.'ri.Grials, namely monoalkoxy-substituted and bialko; - 'y-sub: ituated derivatives of an acotylenediolr "i, and that, there are ; Urnprungsdiol is used in excess, dU>. B.i'1 rtunf- po.'l yraorisJortor Al] '. Ο: κν- verb indungen as

30 9808/137 A

_ 3 -

can be considered minimal, so that one in water is proportionate Easily soluble agent, preferably in the form of a thin liquid solution, is to be expected.

The preferred molar ratio between acetylenediol and Alkylenoxj ^ d or a corresponding compound should are between 1: 0.5 and 1: 0.95, the preferred range being between 1: 0.75 and 1: 0.85, i.e. approximately 1: 0.8. This ratio applies in particular to the reaction of 2-butyne-1,4-diol and propylene oxide.

The reasons for the particular effectiveness of such mixtures will be explained later. However, it is already now notes that the individual reaction products of the mixture, insofar as they are new, are also the subject of the present Invention are. Monoethoxy, diethoxy, monopropoxy, dipropoxy, ionobutoxy, dibutoxy and with higher mono- and dialkoxy-substituted butyne, pentyne and Hexindiols, as a result, the alcohol groups on either side of the acetylene bond, are all more or less suitable to even out coatings and to contribute to the creation of a high gloss thereof.

The invention will first be explained in more detail with reference to the accompanying drawing, wherein

309808/1374

JTigur 1 is a graphical representation in Gewients -.- percent the amounts of 2-butyne-1,4-diol (BD), mono-prop oxy-butindiol (1 "IPB) and dipropoxy-butynediol (DPB) indicates that in the reaction mixture Reaction of various molar amounts of propylene oxide with 1 mole of 2-butyne-1,4-diol were obtained.

FIG. 2 shows a graphic representation of the uniformity of surfaces achieved - measured in % - by BD, MPB and DPB - always in the presence of a 1.5 g / l containing sodium acid solution.

5 -

3 Ö 9 8 0 87 1 3 7 4 bad original

The NMR spectrum for DPB gave the following peaks:

8.89 (doublet, J = 6.8H ₂ , 3H, -CH) 6.58 (doublet, J = '5.8H ₂ , 2H, -GH ₂ .ö) approx. 6.4 (broad singlet, IH, disappears in CF-. ₂

Addition, OH)

6.11 (multiplet, matches a quartet of Triplets, 1H, -CH. (OH).)

5.74 (singlet, 2H, .0.CH ₂ .C = C)
and corresponds to the following structure: Me.CH (OH) .CH ₂ .0.CH ₂ .C ^ C.CHg-O.CH ₂ .CH (OH) .Me. For MPB the NM spectrum showed the following peaks: 8.89 (doublet, J = 6.8H ₂ , 3H, -CH ₃ ) 6.58 (doublet, J = 5.8H ₂ , 2H, -CHg.0)

6.10 (multiplet, matches a quartet of triplets, 1H, CH (OH))

approx. 6.1. (very broad, 2H, disappears at CF-.COgH

Addition 2x0H)

5.75 (singlet, 411, .Cg _2. G = C. CH ₂ )
and corresponds to the following structure: Me.CH (OH). CH ₂ .0. CH ₂ . C ^ C. CII

- 6

309808/1374

Figure 2 shows that at reaction τοη 1 mol of propylene oxide with 1 mole of BD - after the propylene oxide has reacted, the resulting mixture contains 15% by weight of unreacted BD, 48% by weight and 37% IIPB DPB .. wt.... When 3/4 mole of a propylene oxide has reacted with 1 mole of BD, the corresponding mixture contains 26 % by weight of unreacted BD, 50% by weight of MPB and 24 % of DPB. If 1/2 mole of propylene oxide is reacted with 1 mole of BD, the result is a mixture of A3 % unreacted BD, 46 % MPB and 11 % DPB.

FIG. 1 also shows that when less than 1 mol of propylene oxide is used, significantly less DPB is formed while the influence on the amount of MPB formed is very small. Corresponding results are v / grounded when implemented obtained from other acetylenediols with other oxyrans.

The two compounds MPB and DPB were fractionated by Distillation of the reaction mixture from 2-butyne- ■ 1,4-diol and propylene oxide isolated and subjected to proton magnetic resonance analysis.

The plating experiments were carried out on typical nickel plating solutions to which NMR pure MPB and pure DPB were added, which had been separated from the reaction mixture by multiple fractional distillation. These materials came either for themselves _; alone or - in mixtures of different compositions for use.

309808/1374

In Figure 2, the results of the equalization of the "

Surfaces that are created with the help of these individual

bonds were achieved against their concentrations in the Nickel plating solution applied. In all cases, saccharin was present at a concentration of 1.5 g / l. As As can be seen from FIG. 2, the two compounds MPB and DPB are always used as surface-comparing agents effective, whereby DPB is an erheblädae passivation in one causes a certain range of relatively low concentrations of 0.04 g / l. Similar adverse effects, those caused by spots of black nickel plating or by the complete absence of nickel plating in areas of low current density are displayed, the MPB does not show before this is not in a concentration of 0.4 g / l is present. It follows that small changes in the concentration of DPB (namely, 0.01 g / L) are serious the quality of the electroplating layers over cracks, notches and other parts of the objects that are only exposed to relatively low current densities, while with MPB in the concentration range Concentration fluctuations of 0.1-0.4 g / l only have a minor effect on the quality of the nickel coatings. .

Figure 2 further shows that BD / has a max. Limit of homogenization effect slightly below 60 ° o. This roughly corresponds to the best result that has been achieved so far for surface-leveling joints. In contrast, z. B. with ίί? Β in the mixture according to the invention a smoothing effect of so-

- 8 -309808/1374

even reached over 70 % . In addition, as will be explained in detail later, the said maximum of 60% is achieved with a concentration of only 0.05 g / l, while passivation does not occur before a BD concentration of 0.5 g / l.

In addition to the results obtained according to FIGS. 1 and 2, tests were also carried out to determine the effect different mixtures of MPB and DPB to be determined. These experiments were carried out in a Hull cell, those with the usual nickel plating solution with 1.5 .. g / l sodium sacharinate and o-mercaptobenzoic acid (MBA) as Depolarizer was filled. The results are shown in the table below.

The Hull cell used was one made of Perspex acrylic resin manufactured standard cell. The distance between the two parallel sides was 6.3 cm, their height was 3.4 cm and their length 12.5 cm. The length of the brass cathode to be plated was 10 cm. She had an inclination towards it the anode of 38.7 °. The depth of the plating solution in the cell was 5 cm · immediately below the cathode was an upwardly perforated tube installed through which air was passed so that the solution was stirred by the air, particularly in the vicinity of the cathode.

3098 08/137 4

A description of a technical nickel plating system and information about the composition of the baths as well a description of the working conditions for this process, which also apply to the application of the invention Mixtures are suitable are published in Chapter 5 of the journal "Nickel Plating" by R. Brugger 197O by Robert Draper Ltd. Teddington, contain.

Determination of the equalization effect on surfaces by measuring the surface profiles.

The surface roughness is measured before and after plating by measuring the surface with a surface analyzer, this is a so-called "Talysurf" instrument, carried out, which gathers by measuring the vertical movements of a pen which is over a standard length across the surface to be led. The surface quality is determined by the number of deviations of the pen from a straight line Center line determined. The deviations are indicated below with CL.A. (Center Line Average). Of the Initial value for C.L.A. a ground steel test plate was l / i <m, a protective layer was placed on the steel plate of 25 / ^ m and the final value for C.L.A. then determined. The percentage of equalization the surface »was determined using the following formula:

Percentage equalization = initial C.L.A. - End C.L.A.

Anfan ^ n-C.L.A. - 10 -

309808/1374

- ίο - ·

Tabel

Effect of MPB, DPB and MBA on gloss and glazing

the surface

DPB DPB / MBA MPB MPB / MBA DPB / MPB DPB / MPB / MBA C. 0.025 0.025 / 0.01 O.O25 ö.025 / 0.01 O.O5 / O.O5 O.O5 / O.O5 / O.OI L. 36 32 25th 23 58 53 P. 0 0 0 35 MO C. 0.05 0.05 / 0.01 O.O5 O.O5 / O.OI O.O5 / O.O75 O.O5 / O. O75 / 0.02) L. 55 50 40 37 65 60 P. 35 10 0 0 35 0 C. 0.10 0.1 / 0.03 0.10 0.10 / 0.01 0.05 / 0.10 0.05 / 0.10 / 0.03 L. 75 60 60 58 73 68 P. 60 10 0 0 35 0 C. 0.15 0.15 / 0.03 0.15 0.20 / 0.01 0.03 / 0.10 0.03 / 0.10 / 0.03 L. distinct Bumps 65 65 63. . ■ 59- Bumps - P. 85 75 0 0 15th 0 C. 0.25 0.25 / 0.05 0.25 0.25 / 0.02 0.03 / 0.12 0.03 / 0.12 / 0.03 L. clear distinct 75 72 67 62 Bumps Bumps P. 85 85 10 0 15th 0

C = concentration in g / l.

L = degree of equalization in %

P = Degree of passivity as a percentage of the length of the test panel measured from the end of the electrical Field that has the lower current density (current strength = 1 χ A)

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309808/1374

It can be clearly seen from the table above that MPB is not noticeable even at high concentrations leads to passivation. Although, on the other hand, the DPB is evident up to the 0.04 g / l limit is a more effective comparator than the MPB in terms of weight, this cannot necessarily be seen as an advantage as it is difficult under normal working conditions to obtain low concentrations of the agents necessary for shine and ensure uniform surface to maintain.

Some of the following examples reveal the advantages of adding depolarizing agents such as they are shown, for example, in British Patent Specification 920,922. As a typical remedy for depolirization o-mercapto topzoic acid (MBA) was chosen. A reduction in passivation by the DPB in the area " higher concentrations were found. Mixtures containing MPB / DPB with high proportions of DPB can also be used Compare with those tests carried out in the absence of MBA.

It can be seen from FIG. 1 that the relative weight ratios of MPB to DPB within the limits of the preferred molar ratios of 0.5: 1 to 0.95: 1 of the alkylene oxide to acetylenediol are approximately 4: 1 to 1.5: 1 , hence a weight ratio MPB: DPB of approximately 2: 1 corresponding to the preferred molar ratio for the reaction of 0.8: ■ 1.

The table gives 5 examples of pure comparison products formed mixtures MPB / DPB with a weight ratio » from 1: 1, 1.5: 1.2: 1, j *, j5: 1 and 4: 1.

309808/137 4 ₁₉ .

The results, with or without the addition of MBA as a depolarizer have been obtained, show the advantageous effect of mixtures that were prepared according to the invention « A sufficiently high proportion of MPB was obtained without an excess of DPB, which would cause passivation could, brought to application »In addition, it was found that the effects of MPB and DPB with regard to Their equalization of the plated surfaces and the gloss effect of the same add up what for the practical application of the invention has the consequence that either the addition of a depolarizer ^ zur Kompensierung'der Passivation is unnecessary or the addition of larger amounts of additive for a given amount of depolarizing agent enabled, so that the susceptibility of the electroplating process is reduced.

Figure 1 also shows that the reaction of about 0.8 mol Propylene oxide with a 1 mole BD leads to a mixture that has a maximum yield of MPB at the same time relatively small amounts of DPB and unreacted BD. For the plating solution, in fact, it is better that in the mixture by reacting higher amounts of propylene « oxyd with BD, contain somewhat larger amounts of harmful BD are instead of larger amounts of the more concentration-critical DPB.

The following examples are based on propylene oxide and BD as the starting material, especially because of their light weight Availability and mutual responsiveness

309808/1374

are the preferred reactants. Other acetylenediols (following Table 1) and oxiranes (following Table 2) behave in a corresponding manner and .can therefore be used equally for the invention »

309808/1374

Table 1 - Acetylenediols

2-butyne-1,4-diol 2-pentyne-1,4-diol 3-hexyne-2,5-diol 2,5-dimethyl-3-hexane-2,5diol 2,4-hexadiyne-1,6-diol 4,7-dimethyl-5-decyne-4,7-diol

Table 2 - Oxiranes

Epoxy ethane (ethylene oxide) of 1,2-epoxy-propane (propylene oxide) 1,2-Epoxj ^r ~ butane (butylene oxide) 2, 3 - epoxy-butane 1-chloro-2,3-epoxypropane (epichlorohydrin), 1-butoxy 2,3-eporypropane 1-allyloxy-2, jj-c-'-poxypropane

3098 08/13 7

The reaction between the acetylenediol and the oxirane is favored by an inorganic or organic base, z. B. by sodium or potassium hydroxide, or sodium Potassium carbonate or amines such as. B. Trimethylamine, The selection of the catalyst is understandably dependent of its effect on the reaction components, and of the desired reaction rate and solubility of the catalyst in the reaction components and in the final solution, if worked in a solvent will.

In some cases e.g. B., if the acetylenediol is a liquid, the reaction can be carried out without adding a solvent be performed. In general, however, a solvent is required that is as inert as possible should be how this z. B. in the case of aliphatic ethers, e.g. the di-isopropyl ether or heterocyclic compounds such as B. the dioxane or tetrahydrofuran or an aromatic solvent such as taluene is the case. The latter type of solvent is theoretically the best, since such solvents with the oxiranes do not react. Also water or alcohols z. B. methanol can serve as a solvent, especially since side reactions of the compounds with the oxirane are only minor run and the connections formed thereby do not adversely affect the nickel electroplating process impact.

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309808/1374

From the foregoing it is clear that the invention is very different from inventions according to the British patents 864 287 and 970 269.

British Patent 864,287 relates to acetylene alcohols including diols and an epoxy using an epoxy-alcohol ratio of 1: 1 to 20: 1 available reaction products «It is obvious that these products are more or less are polymers. Otherwise, details are only given on reactions of at least 2 moles of epoxy to acetylene alcohols described. However, no mono-substituted compounds of the type according to the reaction products are grounded of the invention disclosed, quite apart from the fact that the special mixture according to the invention does not at all can be generated in any of the ways described in said patent.

British Patent 97O 269 discloses mono- and diallocylated Connections and in particular z. B. the connection:

HOCHgCRj CH ₂ OCH ₂ CPI. (CH,) DH.

However, the individual compounds in this regard are always used together with allyl sulfonic acid, an embodiment which is out of the question for the present invention.

Incidentally, the type of reaction mixture now disclosed and its possible compositions is also included in this Patent not mentioned hinted at.

309808/137 A bad original

The present invention has been described above as a new one Mixture of compounds and as a new one-of-a-kind. bindimgeri. It is, however, for practice meaningful from various points of view, namely:

a) As a method of electroplating nickel deposition, wherein the mixtures or the individual compounds which are added to the electroplating bath are preferred a concentration of 0.001-2.0 g / l, in particular Have 0.01-0.4 g / l,

b) as a bath of the appropriate composition,

c) with regard to the concentrations of the ingredients of a such a bath,

d) with regard to the objects plated by the process and

e) with regard to the additives to nickel plating baths either to deginn the plating or at a later date, the additives of one or more Mixtures or individual compounds according to the invention can exist. You can also use other high gloss and coating uniformity means i / t'f. with the addition of a deposition agent for Application. In addition, the erfindungsgeinsame Agent as such or dissolved or suspended in a harmless medium to the respective nickel electroplating [_sbad added evapor-n.

309808/1374

The compounds according to the invention can be regarded as an additional gloss agent and are then used together with well-known first-class shine agents applied where it is essentially sulfonic acid derivatives, such as B. Aryl and., Unsaturated alkyl sulfonamides, SuIf imide and sulfonates.

Constituents of the plating bath that are contemplated for the preferred practice of the invention are:

1) water.

2) Nickel sulfate, nickel chloride, nickel sulfamate or a Mixture of 2 or 3 of these nickel salts.

3) The organic additive according to the invention.

4) A sulfonate, a sulfonamide, a sulfimide or a or more sulfonates, sulfonamides, sulfimides or Mixtures of the same.

5) If necessary, a thiocarboxylic acid or one or more of their water-soluble salts of ^r IYP and in the concentration according to the British Patent Specification 920,922.

G) a wetting agent if necessary.

Another and often indispensable additive is a Buffer, like «. B. boric acid, formic acid, acetic acid or the like.

3098Ü8 / 13 7 A

BAD ORiGINAL

The examples below are some of the in question coming containing various cooperating additions Plating solutions of improved effectiveness in terms of the luster and flexibility of the nickel silver plating with listed. However, it depends on that in the plating baths more than 100 g / l of nickel sulfate, nickel chloride or nickel sulfamate or a mixture from 2 or 3 of these salts are introduced, provided that their solubility limit is not exceeded.

Some plating solutions, with the help of which particularly shiny and flexible nickel coatings are obtained, whereby the interacting additives are in dissolved form, are the following:

3098 0 U / 13 7

example 1

Nickel sulfate (Hi SO ₄ .6H ₂ O) 300 g / L

Nickel dichloride (Ni Cl ₂ .6H ₂ O) ■ 40 g / l

Boric acid (H ₇ BO. ,,) l \ 0 g / l

Natriuni-o-beiizoyisulfiinicl (sodium sacharunate) 2.0 g / l

o-mercaptobenzoic acid · 0.02 g / l

Reaction mixture from a Hol 2-Butlri- · i, 4-diol

and 0 * ti5 Hol propylene oxide 0.1 ^ g / l

Example 2

Kiekelsulfat. (Ni SO ^ .6H ₂ Q). 300 g / l

Nickel chloride (Ni Cl ₂ .6H ₂ O) 40. g / l

Boric acid (H _V BO.,) 40 g / λ

Sodium o-benzoylfiulfimide (sodium sacharinab) 1.5 g / l

Sodium sulphonate 0.20 g / l

Dithiodiyaleic acid O.Ol · g / l Reaction mixture from T I-Iol 2-butyne-1, A-d. Oil

and 0.7 ^ mol PropyLenoxicL _n 0.20 g / l

309ÜÜ0 / 137 4

BATH ORIGINAL

- ο ι -

3 0 S> 8 l> 0 / 11.74

Deinpiol 3

NickeliJuLfat (Ni So ^ 6H ₂ O) '300

III cke L ch L oriel (IIL Cl ₂ -CH ₂ O) IiQ e / l

Boric acid (H _r B0 ~> Ao ß / .L

HiibrLum-o-benaoylaiilfLiiüd (NatfLumyacharLnab) 1 .0 g / .L

riabriurnallylijiilfonab. 1.0 ^; /].

o-MercciptobenzoofJÜure 0.Ol r / l

RealcbloriiifieiaLscli on j 1 HoL 2 ~ Bub.Lri-1, 4-dioL

UDd 0.8 I-Iol butylene oxide 0. \ [} ι / l

iJois]) iol h

IHckelisulint (Ui S0 _/ .filL.O)

Iiatriiuachiorid i: 0 g

Boric acid (ϊΙ, ΒΟ ,,) ! K) g

Ilabriura-o-benzoyl-riuLfimid (iial.fiuiiiiMcharliiixl;) 1, ¹ J g /

Rep "·: .tioii.s ^ üii'Lsoh from 1 Hol 2 ~ \\\\ l in- i, 4-üJol

iiiul 0.6 Hol Yi> I Lorhj / drin 0. M) ι

Example 5

Ni disgust sulfate (Ui SO ^. 6H ₂ O) 100 g / l

Nickel chloride (Ni Cl ₂ .6H ₂ O) 200 g / l

Boric Acid - (H ₇ Bp ₇ ) 40 g / l

Sodium o-benzoylsulfiraid (sodium sacharinate) 3.0 g / l

o-llercaptobenzoic acid q q2

Reaction mixtures of 1 mol of 3-hexyne-2 _f A-di

and 0.8 mol propylene oxide 0.15 g / l

Example 6

Nickel disgust sulfate (Ni SO _4. 6H ₂ O) 1.00 g / l

Nickel chloride (Ni Cig.6H ₂ O) 200 g / l

Boric acid (H ₅ BO ₇ ) AO g / l

Sodium o-benzoyl sulfimide (sodium sacharinate) 2.5 g / l

o-mercaptobenzoic acid 0.02 g / l

Sodium allyl sulfonate 0.20 g / l Keaktiorjn / = (imsc] j from 1 mol 2-33utin-1, Λ-diol

and 0. · {'. J3o.'i. Ztl) ylene oxide, 0.20 g / l

3 (J ¹ JH fJ i). I Ί Ί h

BATH ORIGINAL

Example 7 100 g / l (Ni SO ₄ .6H ₂ O) 200 g / l (Hi Cl ₂ .6H ₂ O) 40 g / i (H ₃ BO ₃ ) 2.0 g / l d (Sodium ice acliarinate) 1.0 g / l 0.01 g / l

Niekel sulfate

Nickel chloride

Boric acid

Sodium o ~ "benzoylsulfj

Sodium allyl sulfonate

Thiodipropxonic acid

Reaction mixture of 1 mol of 2-butyne-1,4-diol

and 0.75 mole propylene oxide 0.15 g / l

Example 8

Nickel sulfamate (Ni (SO ₃ NHg) ₂ .4HgO) ■ 400 g / l

Nickel chloride (Ni Cl ₂ .6H ₃ O) 5 g / l

Boric acid (H ₃ BO ₃ ) 50 g / l

Naphthalene-1, 3, 6-trisulfonic acid (sodium salt) 12 g / l

Sodium 2-ethylhexyl sulfate 0.5 g / l Reaction mixture of 1 Hol 2 ~ butyne-1,4diol

and 0.09 Hol butyl fatty acidyl ether 0.05 g / l

309808/1374

The components according to points 3) to 6) of the Examples given list can be used for Production of a liquid additive solution; are mixed, whereby an immediately usable solution for the preparation, and maintaining an effective nickel plating bath is formed according to the invention. An additive of the correct composition, consisting of the individual chemicals and not only applicable for the beginning of the plating, is thus created immediately available is composed, but also such May have composition that is capable of reducing the losses of the galvanizing bath by chemical or electrochemical "Consumption or through physical losses, namely compensate for by dragging out plating solution.

Such mixtures can be composed as follows;

Reaction mixture according to the invention 10-800 g / l

Sodium benzoyisulfimide (sodium cacharinate) 20 - 450 g / l Sodium allyl sulfonate 0-100 g / l

o-mercaptobenzoic acid 0-10 g / l

Sodium 2-ethylhexyl sulfate 0 ~ - 5 g / l

A liquid additive for a nickel plating bath, which already contains the inorganic compounds, can be used for conversion into a bath according to the present invention, e.g. B. be composed as follows;

- 25 309808/1374

Liquid additive for starting a galvanizing bath:

Reaction mixture from 1 mol of 2-butyne-t, 4-diol

and 0 * 8 moles of propylene oxide -18 g

Sodium o-benzoyl sulfimide (sodium sacharinate) 200 g

a ~ mercaptobenzoic acid 2g

Sodium 2-ethylhexyl sulfate 25 g

Water to make up to 1 1

To the. To optimally maintain the effectiveness of this bath and To replace the organic compounds to the extent that they have been used up, the following additive- solution to be created:

Additive solution to maintain the effectiveness of the electroplating bath t

Reaction mixture of 1 mole of 2-butyne-1,4-diol

and 0.8 moles of propylene oxide 150 g

Sodium o-benzoyl sulfimide (sodium sacharinate) 50 g

o-mercaptobenzoic acid 2 g

Sodium 2-ethylhexyl sulfate 2 g

Water to top up on 11

309808/1374 -26-

Claims (1)

- 26 patent claims 1) Means to improve plating baths by reacting acetylenediols with less than 1 equimolar of alkylene oxides or similar oxirane compounds consisting of a mixture of unreacted acetylenediols and non-substituted and di-substituted reaction products. 2) mixture according to claim 1, characterized in that the molar ratio between the diol and the oxirane is 1: 0.5 to 1: 0/95 and preferably 1: 0.75 to 1: 0.85. 3) mixture according to claim 1 - 2, characterized in that that the diol consists of 2-butyne-1,4-diol; 2-pentyne-1,4-diol; 2-hexyne-2,5diol; 2,5-dircethyl-3-hexyne-2,5-diol ;. 2,4 ~ hexadine-1,6-diol and / or 4,7-dimethyl-5-dexyne-4,7-diol. 4) mixture according to claim 1-3, characterized in that that the oxirane the .Ethylenoxid; Propylene oxide; 1,2-epoxy but one; 2,3-epoxbutane; l-chloro-2,3-epoxypropane; l ~ butoxy-2,3-epoxy- propane; 1-phenyl-1,2-epoxyethane and / or 1-allylo2y-2,3 ~ r op an IfJt ₁ - 5) mixture according to claim 1-4, characterized in that that the reaction is by an anorgxinic or organic Base is catalyzed. • ta G) Gcii.iinch according to claims 1-5, characterized in that the Dj oil clan 2-Dutin-1,4-dio. 1 and the Oxiran das IVopylono> '.. i c'J i ;; i. 3 098 ^{08/137 U.} "2Ί" BATH ORIGINAL 7) Additive for nickel plating baths, characterized in that that this from a mixture according to claim 1 'to 6 and a harmless solvent for the bath consists. 8) Additive according to claim 7 »characterized in that it is saccharine and / or a depolarizing agent which is soluble in the additive contains. 9) additive according to claim 8, characterized in that it is 10-800 g / l mixture according to claim in aqueous solution 1-6, 20-450 g / l sodium sacharinate, 0-100 g / l sodium allyl sulfonate, 0-10 g / l o-mercaptobenzoic acid and contains 0-5 g / l sodium 2-ethylhexyl sulfate. 10) Aqueous nickel plating bath, characterized in that it contains the mixture according to claim in addition to nickel ions 1-6 and / or the additis according to claims 7-9 contains. 11) Aqueous nickel plating bath according to claim 10, characterized in that sulfenic acid derivatives therein as preferred brightener is included. 12) Aqueous nickel plating bath according to claim 10 and 11, characterized in that it contains a thiocarboxylic acid or one or more of their water-soluble salts is contained. 3 0 9 8 0 8/1 3 7 A 13) method for galvanic nickel plating, thereby characterized in that in the bath according to claim 10 Ms 12 Nickel deposited on a cathode immersed in the bath will. 14) Objects, characterized by a nickel plating according to the method according to claim 13. UV !! 309808/1374