DE2352970A1 - CORROSION-RESISTANT METAL COATINGS CONTAINING ELECTRICALLY DEPOSITED NICKEL AND MICROPOROUS CHROME - Google Patents

Description

Patent attorneys

CM*. Ing.H. Negendank

Pee. Ing.H. Hauck DIpI. Phys. W. Sch mite

Dipl. Ing. E. Gre.aivs

Dipl. Ing, vy. Wehnelt

2 Hamburg 36

Nauer Wall 41

Corrosion-resistant metal coatings that contain electrodeposited nickel and microporous chromium

The invention relates to an aqueous solution for a nickel electroplating bath, the nickel ions, which are soluble in the bath Contains amine in a concentration of about 0.1 g / l to about 10 g / l and a metal salt soluble in the bath, which, when dissolved, trivalent or tetravalent metal cations in an amount of at least about 0.001 g / L to yields about 0.5 g / l, and which precipitates at pH which is lower than that at which the nickel is precipitated in the solution. -.

409818/1107

In the literature it has already been suggested, fine, in the bathroom insoluble, essentially non-conductive particles such as aluminum oxide, titanium oxide, silicon dioxide, barium sulfate, etc. to be dispersed in nickel plating baths for semi-gloss and gloss coatings. When plating, these particles are in high density and then a thin decorative chrome coating is deposited on such a mixed nickel coating deposited in microporous form. This obvious microporosity. Of the chrome coating results in the underlying, Electroplated nickel metal provides improved corrosion protection, which can be attributed to that the anodic corrosion currents in the pores of the microporous chrome coating have a significantly lower current density compared with the case where there are only the usual pores.

It is also known to produce a mixed metal coating by depositing a nickel coating on a nickel substrate to have a particle thickness of 0.076 to 1.27 / u (0.003 to 0.05 mils) and wherein the coating is 1,000 to 1,000,000 particles / 6.45 cm ² (square inch) when using various metal salts such as aluminum trichloride, magnesium chloride and others. No solids are introduced when the microporous structure is deposited. Also in the literature is a method of electrodeposition from a thin topcoat with a thickness of

409-818 / 1107

0.000012 cm (0.0000050 inch) on a substantially nickel base material which is described in the Electrolytically deposited nickel base material contains solids.

It has now been found that an electrolytic gloss

Nickel coating can be obtained from an aqueous acidic nickel solution if the bath solution in the bath contains soluble metal salts, the trivalent or tetravalent metal containing cation in an amount of at least about 0.001 to about 0.5 g / l and their precipitation occurs at a pH value which is relatively lower than that of the nickel in the Solution. The bath solution also contains a bath soluble amine in a concentration of about 0.1 to about 10 g / l. A bath of this type is electrolyzed to put nickel in a thickness to be deposited which is generally greater than about 3.81 / u (0.15 mil), and then the coating becomes used as a substrate in order to electrolytically deposit a thin decorative chrome coating thereon, the at least one Thickness of about 0.25 / U (0.01 mil) is obtained significantly improved protection against corrosion.

The present invention is therefore based on the object to give improved corrosion protection to a metal substrate by applying a bright nickel coating to the substrate galvanically deposited and then a relative

409018/11 07 ■ ". *.

electroplated thin chrome coating. If in the present Registration of "galvanic deposition" is spoken of, this expression is used in the same sense as electrolytic Deposition used.

Nickel is electrodeposited onto the metal substrate as well as copper, zinc, steel, iron and similar substrates. The metal substrate that can be used can be on a plastic such as on polyvinyl chloride, polyvinylidene chloride, Polypropylene, polyethylene, acrylonitrile-butadiene-styrene and similar plastics can be applied. The metal will applied to the plastic substrate after the substrate was sensitized with an acidic tin-palladium compound.

The nickel bath that can be used in the method according to the invention is a normal, aqueous, acidic nickel electroplating bath, which contains nickel brightening additives, usually organic nickel brightening additives. The nickel plating bath usually has a pH of about 1 to 5, and more preferably about 2 to 5. The nickel is used in the Nickel bath usually as a salt soluble in the bath, such as sulfate, chloride, sulfonate, fluoroborate or bromide or the like Salt introduced. Nickel chloride and nickel sulfate are preferably used. The amount of nickel chloride that is used can be in the range from approximately 30 to 300 g / l, preferably it is approximately 60 g / l. The nickel sulfate

4Ö9818 / 1107

on the other hand, is used in an amount ranging from about 100 to 400 g / l, preferably in an amount of about 225 g / l, is used.

In the inventive method, the temperature of the bath, which can be used in the range of about 23.9 ms 76.7 ⁰ C (75-170 ⁰ F), preferably in the range from 43.3 to 65.6 ° C ( 110 to 150 ⁰ F).

The nickel bath can contain considerable amounts of cobalt. For example, the cobalt can be in as high amounts as at least 5096 and it is then in the nickel-containing, electrodeposited layers present. Part of the nickel coating can also be made of an iron-nickel alloy exist, but it is preferred that this be electrolytic Nickel-containing coating is as pure nickel as possible.

The plating baths that can be used according to the invention can also contain other ingredients such as wetting agents, to prevent pitting or pitting, and also buffers such as boric acid, formic acid and the like Connections included.

The current density of the plating baths can range from about 0.5 to 22 A / cm- (5 to 200 ams per sq.ft.), while-

AÖ9S18 / 1107

2357970

rend the anode current density in the range of about 1.1 to 3.3 A / cm (10 to 30 amps per sq.ft.).

The metal containing cations introduced into the bath create porosity in the bright nickel electrolytic coating are those whose precipitation occurs at a pH lower than that of the nickel in the Nickel electroplating bath. The failure of any Metal-containing cations depends not only on the concentration of hydroxyl ions, but also on the concentration of the nickel. In other words, the lower the nickel concentration, the higher the precipitation point be for nickel. In general, these are the bath soluble metal salts that go into the nickel electroplating bath are introduced, those in groups III, V and VI of the periodic table. The cations that used are metal-containing cations in which the metal is aluminum, chromium, thallium, thorium, vanadium, uranium, Can be lanthanum or various oxygenated metal cations (i.e. oxygen-containing metal cations) such as uranyl- ,. Vanadyl and similar cations. Of the cations listed above, preferred metal-containing cations are those which contain aluminum or chromium ions.

The compound containing nitrogen and used in the present Invention can be used, is preferably an im

409818/1107

2357970

Bath soluble amino compound. A preferred amino compound is a compound that is a group of formula I.

-N (-RA) _g (R ') _h (D

contains in which the groups

R independently of one another are alkylene, arylene, hydroxy-substituted Alkylene, hydroxy-substituted arylene, polyoxyalkylene, hydroxy-substituted polyoxyalkylene groups or their chlorine or bromine derivatives mean

the groups A independently of one another denote -N (R ') o> -COOHj -SO ₃ H or -P (O) (OH) ₂ and

. the groups R 'independently of one another are hydrogen atoms, alkyl, aryl, hydroxy-substituted alkyl, hydroxy-substituted aryl, polyoxyalkylene, hydroxy-substituted polyoxyalkylene groups, or the chlorine or bromine derivatives thereof, ^v -

g 0 to 2 and

h are 0 to 2, the sum of g + h = 2.

A preferred amino compound is a compound of the formula II

R " _s -N (RA) _t (II)

R and A have the meanings given above,

R "hydrogen, -, -.. _;

4 0 9 8 18/110 7

-RN ι

RA

RA

RN ■ R ¹

R «

means,

s O to 3 »

t mean 0 to 3 and the sum of s + t = 3 ,

m 1 to 10, preferably 1 to 4,

ν 1 to 20, preferably 1 to 10, * provided that s has a meaning other than 3 when R "denotes hydrogen.

The valences of nitrogen are saturated by the various substituents mentioned above.

In the present invention, preference is given to using a polyamine or a polycarboxylic acid as the amino compound.

Suitable amines to be used in the present invention are the following:

(CH ₃ ) ₂ NH
(HIGH ₂ CH ₂ ) ₂ NH
(HO - C ₄ Hg)

- CH ₂ - CH ₂ NH ₂

(HOCH ₂ ) ₂ N-CH ₂ -CH ₂ -N (CH ₂ OH) ₂

8 18/110 7

HgN - CH ₂ ^ CHg-NH-CHg-CHg-NHg C ₆ H _{5 -NH 2} HgN-CHg-CH ₂ -O ^ CHg-CHg-O] _1-20 H (HO-CHg-CHg) ₂ -N - CHg-CH ₂ -O (-CH-chgo) _1-20 H

CHg-OH

H (O-CH-CH _{2) 1} _20 ° ^"CH 2" ^CH 2 ^{"N" CH} 2 ^"CH 2" ^{N "CH} 2 ^'CH 2

CHgOH 'CHgOH

HN (CH ₂ -COOH) ₂

N (CH ₂ COOH) ₃ '

(HOOC CHg) ₂ N-CHg-CHg- N (CHgCOOH) ₂ (HOOC-CHg) ₂ -N - CHg-CHg-N - CHg-CHg-N- (CHgCOOH) g

CHg-COOH HOOC - CHgNHg HOOC-CHgNHCH ₃ HOOC- (CHg) ₄ -NH ₂ HOOC-CH ₂ -N (C ₃ H ₇ ) ₂ HOOCH ₂ CH ₂ NHg HOOC - CH (NHg) CHgC (O) NHg (HO ) ₂ N-CHg-CHg - N (CHgCOOH) ₂ (HO) (HOOCHg) N-CHg-CHg-N (CHgCOOH) g N

HOOC-CH (NH ₂ ) -CH ₂ ■ = | J- ^ ₁

H ₂ N CH ₂ CH ₂ SO ₃ H CH ₃ HN CH ₂ CHgSO ₃ H (C ₄ H ₉ ) gN CH ₂ CHgSO ₃ H

NHg-C ₆ H ₅ -P-SO ₃ H "." · ■ -

NH ₂ CH ₂ -CH ₂ -CH ₂ - SO ₃ H _; '-ρ'-

(C ₄ H ₉ ) ₂ N -CH ₂ -CH ₂ SO ₃ H

4 O 9 8 -1 8/11 0 1 '' - '

? 3 5? 9 7 G

N [CH ₂ -P (0) (0H) _{2] 3}
HN [CH ₂ P (0)

Also useful are polyalkylenimine derivatives that can be obtained by Polymerization, a compound of the formula

X-CH-CH-Y

Z
receives what

X and Y are hydrogen, lower-alkyl or through Hydroxy substituted lower alkyl and

Z is hydrogen, lower alkyl, lower alkyl substituted by hydroxy or lower alkyl substituted by cyano, wherein the alkyl group is preferably 1 to 3 carbon atoms contains, mean.

The most preferred compound is polyethyleneimine. Other Polyalkyleneimines are disclosed in U.S. Patent 3,393,135 described.

The acids which can be used in the bath can, as stated above, be used as such, i.e. as acids or they can be used as bath-soluble salts such as the ammonium or alkali metal salts thereof, e.g. the sodium or Potassium salts, can be used.

409818 / 11.0 7

In the above compounds are alkyl or alkylene groups is present, it is preferred that they contain 1 to 6 carbon atoms. The term "aryl" as used above is preferably phenyl or naphthyl groups. The term "alkylene" as in polyoxyalkylene and by hydroxy substituted polyoxyalkylene generally means lower alkylene, preferably with 2 to 4 carbon atoms. The term "alkylene" means a saturated alkylene group.

If the nickel plating bath composition according to the invention is used and the "Dubpernell copper plating test" is carried out to reduce the porosity of the decorative chrome plating, as described above, on which bright nickel was deposited, a porosity count is obtained for a thickness of 3.81 / U (0.15 mil) nickel which is as high as 10,000 pores / 6.45 cm (square inch), while a much higher value is obtained for a thicker nickel coating. Using a nickel plating of 7.6 to 12.7 / U (0.3 to 0.5 mils) in thickness, the porosity count is for

the decoration chrome coating often higher than 300,000 pores / 6.45 cm. In general, the microporosity in the decoration chrome coating with the additives according to the invention can have values

of approximately 60,000 pores / 6.45 cm without the Bright nickel plating from 3.81 to about 50.8 / u (0.15 to 2 mils) thick becomes noticeably dull or dull. at Surfaces that have round contours can be counted with pores

409818/1107

? 3 5? 9 7 O

reach values of about 100,000 / 6.45 cm in chromium without that severe dullness occurs with thicknesses of the nickel from 3.8 up to about 50.8 / u (0.15 to 2 mils).

In the present invention, it is particularly advantageous that it is not necessary to use a separate bright nickel bath, the added, dispersed, fine, insoluble in the bath, contains non-conductive particles to a thin (around a To avoid becoming dull) Bright nickel coating, which simultaneously contains many separated, fine particles, on the thicker, common nickel plating to a thickness of about 3.8 to about 50.8 / u (0.15 to 2 mils). This latter Process in which particles are used results in the final chrome decorative coating - a high microporosity, it can, however, be used in some automatic plating devices designed for an additional nickel bath, which is the added, contains dispersed fine particles, does not contain any facilities or space, cannot be used.

Become water soluble aluminum or chromium salts like the chlorides, sulfates, fluoborates or sulfamates without the previously mentioned, in the bath soluble amino compounds such as EDTA (ethylenediamine-tetraacetic acid and its sodium, potassium, Lithium, magnesium, iron, nickel or cobalt salts), asparagine, etc., then you will not get good results.

409818/1107

nits. Indeed, harmful "burning" (a degraded, limited cathode current density) occur when the concentration of aluminum or chromium ions in the nickel bath Values of approximately 0.5 g / L or higher are achieved. Without the regulating ones Effects that occur in the presence of amino compounds, especially in the case of amino compounds, the acid groups contain, occur, the formation of excessively large, colloidal, hydrophilic particles of aluminum and chromium oxides or their basic salts cause visible unsightly staining in the bright nickel coatings. Mainly for this reason one considers the presence of the foreign materials, namely the aluminum and chromium salts, in acidic nickel baths as impurities, and therefore become this is filtered off from the bath at pH values of approximately 3.5 to 5 »5. Aluminum can get into the nickel baths when aluminum objects are coated with nickel and some Parts of the plating racks fall into the nickel baths. Chromium can get into the nickel bath from defective plating racks, which are periodically passed through the nickel and chrome plating baths. Definitely be by the usual filtration that is used in bright nickel baths used, these ions are removed from the bath as hydroxides when the pH of the nickel bath is around 3 to 5 * 5.

In the present invention, however, water-soluble ones become Salts from aluminum and chromium and other metal cations such as

4098

? 3 5? 9 7 Q

described above deliberately added and their concentration is made by controlled, continuous addition or by adding at certain intervals during plating held at the effective or appropriate value. Since it appears that a colloidal salt which is insoluble in the bath is slowly formed, these metal cations are continuously removed from the nickel solution by filtration.

Virtually all gloss solutions are filtered and this is usually done continuously. This is especially true for nickel baths, which are agitated by air or mechanically. These stirring methods are also the best methods dispersed around the colloidal hydroxides or the basic salts of these metal cations as colloids in the nickel baths to keep. In filtration, it is necessary to remove the impurities that come from the air, anode particles Among other things, to remove the colloidal particles, which are called hydroxides or basic metal salts of the cations as present on aluminum, chromium and other compounds described above. The multivalent cation can be in a as low as 2 mg / l may be present during the concentration of amine can be as low as 50 mg / l while still maintaining a considerable increase in microporosity in the Chrome decorative coating is obtained when the underlying glossy nickel coating, which is made from baths, has the low level Contains concentrations of additives in the upper thickness range is about 12.7 / U (0.5 mils).

409818/1107

The average concentration of metal cations used, present in the nickel plating bath is usually in the range of about 1 to 50 mg / l and that Amino compound is used in a concentration of about 0.5 to 10 g / l when the thickness of the nickel plating Is 3.81 to 12.7 / U (0.15 to 0.5 mil) and it is something lower when the thickness of the bright nickel coating is about 25.4 to 50.8 / U (1 to 2 mils), for example then use concentrations of approx. 0.1 g / l. The suitable range of the amino compound is about 0.1 to about 10 g / l. In the chrome decoration coating a maximum microporosity is reached, the higher the concentrations of the salts of the metal cations, and if one is at the Nickel bath uses an upper pH range (4 to about 5.8).

The organic amino compound that co-operates with the cations and that is most suitable is one Compound which can be used within a wide range of concentrations without affecting the usual effects Brightener interferes with. Or adversely affects the properties or qualities of the electrolytic coating, i.e. causes that no coating is deposited in the areas of low current density or that brittle coatings are formed. In this regard, the amino acids such as diethylenetriaminepentaacetic acid, the pentasodium salt (DTPA), N-MethyItaurine, ethylenediamine-tetraacetic acid and similar compounds especially

'409818/1107

more effective and suitable »

Although some ^S8 secondary ³³ Glangmittel (lickelglanzmittel the type of! Class® H) ₉ containing amino groups such as tetraethylene = -pentamin or quaternary Pjridinpropansultonp sometimes-in are effective with the metal-containing cations of the formation of microporosity _together's true the optimal concentration © _{s in} order to avoid microporosity _s not with the concentration above @ r © in _P that is required to produce electrolytic ₉ galva-

Therefore, the preferred organic amino compounds are not brighteners and are effective within a wide range of concentrations <>. Their effect on the gloss _v the egalisiemang land the physical and mechanical properties of the coatings is practically neutral ο

As mentioned above, ₉ preferred are cations ₉ used in conjunction with the amino compounds ₉ cations of the Periodic Table of Groups UIr, ¥ and ¥ 1 = »However, besides this, _{9 it has been} found 9 that a large number of other metal cations in addition to those mentioned above Compounds of groups III, V and VI can be used as those of groups I and II of the periodic _{table s} weaa la the bath particles that are insoluble in it should be filled »

It was also found ₉ that the microporosity _s induced in the decoration chrome coating or ο formed where very finely divided, amorphous silicon dioxide powder in such low concentrations x * / ie about 10 mg / 1 to at most usage = about 10 g / l in the Glanznickelplattierungsbädernp which he = · findungsgemäSen additives "dispersed is _s is equal to the obtained ₉ - when 20 to 60 g / l of the same amorphous fine _p ^¥ Siliciumdioxydteilchen ₉ dispersed in conventional Glanznickelplattierungsbädern ,, the like under the same conditions _{Bath agitation 9} pH _p temperature and coating thickness are operated _B used »With the greatly increased Co = deposition of the very fine ₉ amorphous silicon dioxide particles, the bright nickel coatings can be a little too dull ^ if coating thicknesses are used that are greater than about 3 _S 81 / U (O ₉ 15 mil) ₉ especially _Ό if the concentration,

tion to the fine Siliciumdioxydpulver ₉ dispersed oil bath in the gloss nickel, is greater than about 0 _s 3 g / l "

This is in contrast to the results obtained when there are essentially no particles (about 10 parts per million) in the bath and only the metal containing cation and nitrogen containing compound are present in the bath in the latter case ₉ high gloss nickel coatings are obtained even if the nickel coating is approximately 25.4 to 50.8 / U (1 to 2 mils) 'thick *

4098 18/1107

The finely divided SiIieiumdioxydpuluerj, di © are generally as microfine j precipitated Siiieiuiiaiosiyde or micronized synthetic Siliciiamdioxyde referred to and used in concentrations nerden _s which are as low as 10 are up to 300 mg / lp during the common deposition of the Glanzaickel ax substantially more effective ,? to whom one adds a low concentration®®, of salts of the above beseliriebenea Matallkatioasia »This effect is increased by an addition © by Jaia © säMr © a Ia low ILowzen irations such as EDSA ₉ DfPA etc., the Versrsia & ung of about 0 ₉ 3 ^ is 2-g / l. fine amorphous ₉ Siliciusadioxyd-_ particles together with the novel additives in gloss nickel plating baths results in a very 'microporosity density in the chromium decoration coating _s which is equal to _s as they are at the same Mickeldicke at least 20 g / l of the same powder in Wick bath receives "The _{9 means} that the co-deposition of the silica particles is so strong that a gloss plating of only 1 to 2 minutes at 50 smps / sq.ft. is required to deposit a microporous coating, ie a chromium earth _{Oration coating r} which has a strong microporosity j whereas in a conventional glossy coating at least 20 g / l of the same silicon dioxide powder would have to be dispersed. With these short plating times of 30 seconds even up to. 5 minutes at a cathode current density Ei of approximately 4.4 to 5 »5 A / cm (40 to 50 amps / sq.ft.), It is not necessary to filter and it is easier, under these conditions, to determine the concentrations of metal-containing cations in the Regulate bathroom.

409818/1107

■ - ¹⁹ - - 2352370

Obviously, the multivalent cations absorb Siliciumdioxydteilelien and iferden positively charged ₉ and therefore the fine Siliciumdioxydteilchen be more easily deposited along with the nickel "Without the metal cations the Siliciumdioxydteilchen almost have a neutral charge" The amino acids in the nickel solution also help _s to facilitate the CG capture mnd particular ₂ when polyvalent cations are present "the aluminum and chromium salts such as other metal salts and amino acid can werdenρ used instead of adding the metal salts and amino acids separately.

The silicon dioxide powder can also be added to solutions of these polyvalent cations with or even without amino acids and when evaporating to dryness the silicon dioxide powder is partially or completely coated with salts or hydroxides of the polyvalent metal cations and has the same increased effectiveness for co-deposition with the nickel -.. "ness in fact support together with finely divided Siliciumdioxydteilchenp dispersed in the nickel plating baths j polyhydric metallizations such as those of cerium (XIX) - and cerium (IV) = salts ₉ salts of the rare earth elements such as salts of lanthanum _s neodymium and praseodymium and the mixtures of salts of the earths side ₉ known as didymes salts, "the Cto-deposition of the fine silica particles strongly" apparently by adsorption on the silica, although these salts themselves do not readily form hydroxides in nickel baths

1107

Central concentrations of magnesium ions above 1 g / l promote this effect. The Yerdampfungsver'fahren _s mentioned above ^ j arise when they are used in iron salts together with the SiIiciumdioxydpulver, iron (Il) - ions and iron (XIL) which are more effective than when they are added separately.

The method described ₉ to improve the co-Äbscheidung the fine Siliciufudloxydteilelien, also the co-deposition promoting fine "in the bath of insoluble particles of silicates and metal oxides ₉ although let cers in nickel baths without a special additive as the present invention, a positive Accept charge. The additives according to the invention are most effective in the case of fine, amorphous silicon dioxide particles.

The amount of fine particles that are insoluble in the bath that can be used is in the range of 0.1 to 10 g / l, with the size of the particles in the range of about 0.015 to about 10 / u. because of the remarkable activity of the insoluble carrier particles in the bath with the Metallkat- must "ion only very small amounts are used in the bath of insoluble particles" the higher the concentration of metal-containing cations present invention is _p uiso stronger the demand ;, dia concentration of amine to increase ₉ so that the best possible results are obtained =

4 0 9 018/110

In addition to the aforementioned _p Bad.unlöslichen in part previously = surfaces are other insoluble particles in the bath ,, which can be used, polyvinyl chloride polyvinylidene chloride ₀ polyethylene, polypropylene ₉ talc _p Galciumcarbonat and other ^ in U.S. Patents 3,152,971 ₉ 3 152,972 and 3,152,973 '.

The following examples explain the invention without restricting it. “Unless otherwise stated”, all temperatures are in ⁰ C and all percentages are expressed by weight,

example 1

1 ο A semi-technical experiment was made with the following Solutions implemented

Nickel Sulphate 325.06 g / L (43.4 oz / gal)

Nickel chloride 68 ₉ 90 g / l (9 * 2 ")

Boric acid 53 * 92 g / l (7.2 »)

As brighteners were available

Bis-benzenesulfonamide 1.3 g / l

Sodium allyl sulfonate 2.1 g / l - = 0 - C ₂ H ₄ SO ₃ Na

₂ J _{4 2} H ₄ SO ₃
C-CH ₂ = 0 -C ₂ H ₄ -OC ₂ H SO ₃ Na 60 to 90 mg / l (hereinafter referred to as BDOES)

409818/1107

2357970

To eggs bath solution warden 1 ₉ 8 g / l microfine silicon dioxide, 15 mg / 1 Al '(as aluminum sulphate) and 1 g / l Diätixfientriamin pentaacetic acid sis Matriumsalz added = Di © Lösmig itfurde maintained at a pH value of 3 ^ 8-4 and a temperature of 60 to 63 ⁰ C (14OTaLs 145 ⁰ F) was used. It was stirred with air.

Thin nickel coatings _s about 1 _C 27-2 _P 54yu '(0 ^ 05 0 _s i mil) thick warsn ^ mrden? Overplated on the CSlanzEiickel and then x ^ urde chromium "in a thickness of about O ₈ 25 / U (. Og01 mil) auxplated ο

It became a standard = Dubpernell = test for microporosity of the chromium and established that the porosity -40,000 pores / cm (256,600 pores / sqoin.) Was =

Example 2

However, it was the same experimental setup as described in Example 1 _s used contained the bath solution as an additional Glanzstoff 1 _S 4 g / lo = Benzoyisulfimid and there have been conducted further Porositätsversuciie. These tests were carried out on _separations which had essentially the same thickness as in Example 1.

The porosity after the Dubperaell test was 58 885 _c 7 / cm (250 800 pores / sq.in »).

4 0 9 8 18/1107

In this experiment the concentration of microfine was Silica was 1.9 g / l and the Al concentration was 13 mg / l. The amino acid concentration was 1 g / l.

Example 5

A Watts type wrapping solution with the following composition was used!

KTickelsulfat 291.1 g / L- (39.0 oz / gal)

Kickel chloride 62 "9 g / l (8 ₉ 4 ^8ä )

Boric acid 41 ₉ 9 g / l (5.6 ⁸⁹ )

It contained the following glossy ingredients

(1) 1 ₉ 5 wt. 96 mixture of saccharin (! Atrium salt)

and a small amount (approximately O ₉ I g / L) of bis-benzenesulfonimide

(2) O ₉ ? Weight? 6 mixture of sodium allyl sulfonate

(2 _S 1 g / l) and BBOES.

An air agitated solution at a temperature of 60 to 63 ° C (140 to 145 ° F) was used to run experiments with a volume of 227 l (60 gallons) _{or similar}

(a) This solution was turned into a bright nickel coating approximately 101 ₉ 6 / u thick. (Q _s 4 mil) and then chromium was plated to a thickness of about 0.25 / U (O ₉ Oi mil) »The porosity according to the Dubpernell test was less than 15» 5 pores / cm (100 pores / sq .in.).

(b) Then 0 _p 2 g / l diethylenetriamine pemtaacetic acid (Ma-Salz) and 12 _S 5 mg / l Al were added to the solution

4 0 9 8 18/1107

and the solution was stirred and electrolyzed overnight. ■ The pH of the solution was adjusted to 4.0.

A bright nickel coating approximately 10 thick _; 1 / u (0.4 mil) was plated from the solution and then chromium was plated therefrom to a thickness of 0.25 / u (OyOI mil). The porosity according to the standard Dubpernell test was 5620 pores / cm (36 250 pores / sq.in.)

(c) The pH of the solution from experiment (b) was adjusted to 3.0 and bright nickel-chrome became in the same manner plated. The microporosity of the chromium deposit was 3480 pores / cm (22,500 pores / sq.in.).

(d) A further 5 mg / 1 Cr, added as sulfate, were added to the solution described above under (c).

A shiny coating of nickel and chrome, which are on the same

Way as in examples (a), (b) and (c) was plated,

showed a microporosity of 10 271 pores / cm (66 250 pores / sq.in.)

Example 4

Laboratory tests were performed on the Watts type nickel solution of Example 3 with air agitation at a solution pH of 3 * 8 to 4.2 and a temperature of 63 ° C (145 ° F). Air was stirred. The gloss agent concentration was 2% No. 1 and $ 0.755 No. 2 *

409818/1107

To this solution were added 25 mg / l ^"+ Al (as aluminum sulphate), O _S 5 g / L diethylenetriamine pentaacetic acid (Ma = salt) and 10 mg / l microfine Siliciumdioxydo

A bright nickel coating was plated on and over from this solution to a thickness of approximately 10.1 6 / U (0.4 mil)

became a chrome plating with a thickness of 0 ₅ 25 / U (0 _P 01 mil) ■. «-

.plated o

The porosity, determined according to the Dubpernell test, was 7751 j.9 pores / cm ² (50,000 pores' / sq.in.).

Example 5

Further laboratory tests were carried out ₉ using air-stirred solutions of the following compositions

Nickel sulfate 200 to 300 g / l.

Nickel chloride 40 to 120 g / l

Boric acid 40 g / l

The solution was stirred at temperatures of 60 to 65 _S 6 ° C (140 to 150 ⁰ F) and a Löswngs-pH of 3 to 4 _D 7 verifendet "

Individual experiments were carried out ₀ whereby the following additives © were added to the winding solution and the microporosity of the deposited chromium was also determined in the individual experiments »

409818/1107 '

Al ⁺ " ¹ " ¹ "41 mg / 1

th

G/

Biäthjrlentriamis-TDemtaessigsäisire (25 () 0.5 g / l * 3876 rock 6356 _B 6 forums / cm (4 /

35 _B / 41 000 por- es / sq ^ in «

Al ⁺⁺⁺ 82 mg / 1

N = methyl taurine (ITa = salt) 1 g / l TIpSO /, 100 mg / 1

(DTPA) 1 g / l

46 201.5 Ms 74
(298000 = 478000 pores / sq .in <

3876 or more pores / cm (25 OCO or more por-es / sq »iac

Sulfanilic acid 1

I Bsg / l

Th- \ - 4 ' (as Sioriuaf luoborat ^ 10 to 20 iig / 1 (DTEi) 40 to 80 sag / 1

U5 to

microfine silicon dioxide

(4 / u) 0.5 Ms 1.0 g / 1 283 ~ b ± & 8527 poresi / can ~

(1825 to 55000 pores / sq.in.)

N [CH ₉ P (OH) ₅ ]

2 ^J 3

2 ₉ 0

ei _ s p_ ie 1 6

A Mickel solution made by Watts lrt ϊπιΜθ and to that

one added.

Saccharin 1 _S 5 g / l

Sodium _{aXlylsulforAat 2 9} 8 g / l BBOES '60 to 90 m.

The pH of the solution was 4 μmu. the temperature

63 ⁰ C (145 ⁰ P). One stirred with iaaft ",

To the Löstiag add © Eaix O ₉ S g / l Diethj ääurs (Ia = SaIz) together with 25 ag / l Al HoO Io

[as

403818/1107

Bright nickel with thicknesses of 10 _s 2 to 12 _S 7 / U (0 _s 4 to 0.5 mils) was deposited and then only chromium was plated to a thickness of about 0 ₀ 25 / U (0 _p 01 mils).

A standard Dubpernell-test was conducted to _see the porosity of the chromium determined to "moderate and microporosity was found

10 mg / l ferric ions (as ferric chloride) were then added was added to the solution and the plating test described above was repeated. The microporosity was found to be of the chrome, compared to the previous experiment, was improved.

The thickness of the electrodeposited chromium coatings can range from about O ₉ 101 to about 2 ₅ 02 / u (0.04 to 0.08 mils) »

409818/1107

Claims (1)

Claims 1. Aqueous »acidic nickel bath solution for electroplating, containing nickel ions, an amine soluble in the bath in a concentration of approximately 0 _? 1 g / l to about 10 g / l and a bath-soluble metal salt which in the solution gives trivalent or tetravalent metal-containing cations in an amount of at least about 0.001 g / l to about 0.5 g / l, precipitate them takes place at a pH lower than that of the nickel in the solution. 2. Bath solution according to claim 1, characterized in that the metal-containing cation is a metal of the groups III, V or VI of the Periodic Table of the Elements are used. 3. bath solution according to claim Z _9, characterized in that the metal-containing cation is present in the bath in an amount in the range from 0.1 to 50 mg / l. 4. bath solution according to claim Z _9, characterized in that the nitrogen-containing compound is present in an amount in the range from about 0 _s 1 to about 10 g / l. 5. bath solution according to claim Z _9, characterized in that a polyamine is used as the nitrogen-containing compound. 409818/110? 235-970 6. bath solution of claim ₉ wherein Z _s that the amine also contains an acidic group, " 7 «Bath solution according to claim Z _9, characterized in that the nitrogen-containing compound has an acidic group such as a carboxylic acid group ₉ sulfonic acid group © der / iaad. Phos = phonic acid group contains ₉ which is irorfeamdea in d @ m molecule » 8 _v ο bath solution of claim 2 characterized in that _S is a nitrogen-containing compound is used a compound -1. (-RJk) a group of the -formula - (R ⁹⁾ wherein ih ^ R is an _{alkylene- "?} Arylene- _S alkylene-j substituted by hydroxy, arylene-j substituted by hydroxy = _P polyoxy = · alkylene = ₂ hydroxy-substituted polyoxyalkylene = group and / or the chlorine or bromine derivatives thereof, A denotes -N (R ⁵ ) * - COOH ₉ -SO ₃ H or / and -P (O) (OH) ₂ , and R ⁸ hydrogen ₉ denotes an alkyl = _{ΰ substituted} by hydroxy == alkyl- _p polyoxyalkylene- _s , hydroxy-substituted polyoxyalkylene = group or the chlorine = or broad derivatives thereof ₉ g means 0 to 2, h is 0 to 2 and the sum of g -f h - is 2. 9 c bath according to claim S ^ thereby gekemiseielaEiet ^ that one as nitrogen-containing FerMnctaiK an AmIb. the formula R "-M (RA). Used ,, wherein O hf and A have the above given B® £ in ± t, ions- , ⁸ hydrogen _g ] Γ 1 RH = 11 = RiL cdez * = 4 = E = E Ri, s O "to 5 means ^ ΐ 0 means Ms 5 and the Seme γοη s -i- t = 3 be = wears j m is 1 to 10 and γ 1 to 20 means ρ provided _s that s "has a different meaning than 3 ₉ i-jezin R ⁰³ means hydrogen« Qo Bad nacb. Änspr-ucii 9 _S dadurcli gekenazelenaet that -M (R) ρ means = 1 ο Bad after insprueh 9 »thereby gelcsiaazelcmiet _s daa? · = COOH means» 12o bath according to / in claim 9 ₉ thereby gekenazeieüaiet ₂ that Δ = SO ^ H means Bath according to claim 9 _ΰ characterized by g @ k, Qmrt.z® ± oluiet _v that means _o 4 u y © ι ο / ι j ο // 14.-. Bath according to claim 9 "characterized in that R means alkylene 15 «bath according to claim 9 _S characterized in that means" . RA m 16. Bath according to claim 9 characterized in that _{P s} that R 'hydroxyalkylene means " 17 · Bath according to claim 9 _9, characterized in that R "-E- RN -J- R" means.
R «ν 18. Bath according to claim 9 _S, characterized in that the amine compound used is diethylenetriamine-pentaacetic acid. 19. Bath according to claim 9 _S, characterized in that the amine compound used is ethylenediamine-tetraacetic acid, 20. Bath according to claim 9 _S, characterized in that the amine compound used is N-methyltaurine, 21. Bath according to Claim 9 5 ₉ characterized in that there is used as an amine compound M- [CH ₂ -P (O) (OH) ρ] ^ " 22 ο bath according to claim 9 _S characterized ₉ that it also contains fine, insoluble in the bath particles ₉ in 409818/1107. in an amount in the range from about 0.1 to about 10 g / l available. 23. Process for the production of an anti-corrosion coating on a metal substrate, characterized in that one a current from an anode through an aqueous, acidic nickel electroplating bath solution, which contains nickel ions and an amine soluble in the bath, to a cathodic workpiece during a time sufficient for a nickel coating to form, with at least about 1 mg / l of a metal in the bath containing cation is present, the precipitation of which occurs at a pH lower than that of the Nickel in the solution, and then a chromium coating is electrodeposited on the nickel-plated substrate, whereby a microporous chrome coating is formed. 24. The method according to claim 23, characterized in that the metal-containing cation is a metal of the groups III, V or VI of the Periodic Table of the Elements are used. 25. The method according to claim 23, characterized in that the metal-containing cation in an amount in the range from about 1 to about 50 mg / L. 26. The method according to claim 23, characterized in that the nitrogen-containing compound in an amount in the range from about 0.1 to about 10 g / L. 409818/1107 27. The method according to claim 23, characterized in that the nitrogen-containing compound is a polyamine
used. 28. The method according to claim 27, characterized in that that the amine also contains an acidic group. 29. The method according to claim 24, characterized in that the nitrogen-containing compound contains a group of the formula -N (-RA) (RO ₁₁ , in which R is an alkylene, arylene, hydroxy-substituted alkylene, hydroxy-substituted arylene, polyoxyalkylene, polyoxyalkylene group substituted by hydroxy and / or the chlorine or bromine derivatives thereof, A is a group of the formula -N (R ¹ ) ₂ * -COOH, -SO ₃ H or -P (O) (OH) ₂ , R ^{1 is} an alkyl, hydroxy-substituted alkyl, polyoxyalkylene, hydroxy-substituted polyoxyalkylene group and / or the chlorine or bromine derivatives thereof or
Hydrogen means g means O to 2, h means 0 to 2 and the sum of g + h = 2. 30. The method according to claim 29, characterized in that that the nitrogen-containing compound is an amine 409818/1107 Formula R "-N (RA) ₊ used, wherein R and A have the definitions given above, R "is hydrogen, a group of the formula RN RA HA or R-N R * R ¹ means, s 0 to 3 means ₉ t means 0 to 3 and the sum of s + t = 3, m 1 to 10 and ν mean 1 to 20, provided that · s is another Has meaning as 3 when R "is hydrogen. 31. The method according to claim 23, characterized in that the electrodeposited chromium coatings are thick ranging from about 0.102 to about 2.03 / u (0.004 to 0.08 mils). 409818 / 11G7