JPS627278B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Various aqueous electroplating baths and methods for electrodepositing nickel-iron alloys onto conductive fabrics are known and widely in use. Such nickel-iron alloy coatings have excellent corrosion resistance and are particularly useful when plating on corrosive fabrics followed by chrome plating to provide a decorative finish. It is extremely important that such nickel-iron decorative coatings are characterized by high smoothness, good gloss and good ductility, and that these properties are uniform over the entire plated surface. be.

Representative examples of known nickel-iron plating baths and methods are U.S. Pat.
No. 3806429; No. 3812566; No. 3878067; No. 3974044; No. 3994694; No. 4002543;
It is described in the same No. 4089754; the same No. 4101387; the same No. 4134802 and the same No. 4179343. Although the nickel-iron plating bath compositions and methods described in the above-referenced U.S. patents provide satisfactory lick coatings for decorative uses, these conventional nickel-iron plating baths are free from contaminants and long-term use of the baths. It has the disadvantage that it is susceptible to the effects of organic deterioration products generated during the process, and this impairs the properties of the plating film. This problem is particularly acute in plating baths that operate at a pH of about 3.4 or higher to produce high iron content plating coatings containing about 35% or more iron. As contamination by organic deterioration products from grease, oil, and organic bath additives used progresses, the physical properties of the plating film are significantly impaired, and bath operations require relatively strict control in order to maintain a high-performance plating film. Significantly restricts parameter tolerances. Progress of bath deterioration can be confirmed by the formation of white spots or black areas on the film in the medium current and low current density regions.
Furthermore, this deterioration in the physical properties of the plated film can be discerned from significant electrodeposition stresses, poor ductility and, in some cases, inadequate adhesion.

According to this invention, during operation of the bath, it suppresses the harmful effects of bath contaminants, allows operation at higher levels of PH, provides excellent gloss and smoothness, and provides tolerance of parameters for bath control. and consistently produce the desired high quality nickel-iron alloy coating. The present invention also contemplates the use of special replenishers for previously known nickel-iron solutions, which, when used in certain amounts, are effective in achieving the aforementioned benefits. In addition, the present invention also maintains the original performance of conventional nickel-iron plating baths in which contaminant build-up has made it difficult to produce superior coatings with the addition of a certain amount of retreading agent. It is intended as a rehabilitation method to rehabilitate the bath.

The advantages and inventive step of the compositions according to the invention include the addition of an iron solubilizing agent, a buffering agent, preferably one or two of the known A first class brightener in combination with a second class brightener in an amount sufficient to produce a bright, smooth nickel-iron film, and the pH of the bath is within the range of about 2.6 to about 4.5. hydrogen ions and present in at least about 2 mg/amount to give the following structural formula: i.e. [Here, R is H or an alkyl group having 1 to 4 carbon atoms, n is an integer of 0 to 4, m is an integer of 0 to 1, and X is H, NH ₄ , or bath-soluble an aqueous metal containing a type of bath-soluble additive or a mixture thereof, suitable for electrodepositing glossy and smooth nickel-iron alloy coatings on conductive fabrics; This can be achieved using an acidic plating bath.

Particularly preferred additives corresponding to the above structural formula are propargyl sulfonic acid and its alkali metal and ammonium salts and mixtures thereof. Generally, additives are used at about 300 mg/or less, preferably about 5 to 80 mg/.

According to the present invention, a fabric is immersed in a plating bath of the type described above to be used as a cathode and to form a nickel-iron alloy plating of about 105 to about 180 mm until a desired plating thickness is obtained. 41℃ to 82℃)
By plating for a sufficient period of time, a shiny, decorative, and extremely smooth nickel-iron plating film can be produced on the conductive fabric. The electrodeposition of this nickel-iron alloy is about 5 to about
It is achievable over a wide current density range such as 100 ASF. Additionally, the present invention provides a method for replenishing a nickel-iron bath by intermittent or continuous addition of additives to maintain optimum bath efficiency, and at the same time adding a rejuvenating agent to a contaminated and inefficient bath. It is intended as a method for rehabilitation to optimal operating conditions.

Other inventive steps and advantages of the invention will become apparent from the description of the preferred embodiments given together with the examples.

The invention is particularly useful for the electrodeposition of decorative nickel-iron alloy coatings onto conductive fabrics that can be used as a base for subsequent chromium electrodeposition to impart desired decorative and/or corrosion resistance properties. . Although the present invention is useful for electrodepositing nickel-iron alloys onto metal fabrics, it may also be useful to deposit a nickel or copper layer thereon to make the plastic fabric amenable to the nickel-iron alloy electroplating operation. It is also applicable to plastic fabrics which have been suitably pretreated according to known methods for applying such conductive coatings. Typical of such plastic materials are ABS, polyolefins, polyvinyl chloride and phenol-formaldehyde resins.

According to the composition according to the invention, the aqueous plating bath has as its essential ingredients nickel ions, iron ions, and maintained at a desired concentration in the solution in order to produce a nickel-iron alloy film with high gloss and excellent smoothness. Amounts of iron solubilizers, buffers, preferably one type 1 brightener in combination with one or two type 2 brighteners, to reduce the pH of the bath to about
2.6 to about 4.5, preferably about 3.2 to about 3.8, and hydrogen ions present in an amount of at least about 2 mg/h and having the following structural formula: [Here, R is H or an alkyl group having 1 to 4 carbon atoms, n is an integer of 0 to 4, m is an integer of 0 to 1, and X is H, NH ₄ , or bath-soluble metal and contains one type of bath-soluble acetylenic additive or a mixture thereof.

The additive corresponding to the above structural formula is 1-butyne-
3-sulfonic acid, 1-pentyne-5-sulfonic acid, propargyl sulfonic acid, and alkali metal and ammonium salts thereof. Among these, propargyl sulfonic acid and its bath-soluble salts are preferred additives. The additive or mixture thereof is usually used in an amount of about 2 to about 300 mg/, preferably about 5 to about 80 mg/. When propargyl sulfonic acid is used, it is usually used in an amount of about 2 to about 200 mg/, preferably about 5 to 40 mg/.

The addition of organic additives according to the present invention allows relatively iron-rich nickel to be coated with a relatively high iron content of about 35% and above using the upper bath operating pH that allows improved gloss and film smoothness to be achieved. Enabling electrodeposition of iron alloys. Additionally, the additive reduces the bath's sensitivity to organic contaminants such as oils and greases and to organic deterioration products of organic additives contained in the bath, allowing continuous operation without tight control of bath operating parameters. It becomes possible to avoid the formation of vitiligo or uneven skin. Additionally, the present invention provides that by adding specific amounts of additives, contaminated baths that have lost their ability to produce superior nickel-iron alloy coatings can be refilled and rehabilitated to restore proper bath operation. It is intended.

According to the composition according to the invention, nickel and iron ions are added to the bath as bath-soluble and compatible nickel and iron ions. Preferably, inorganic nickel salts such as nickel sulfate, nickel chloride and the like as well as other nickel materials such as nickel sulfamate and the like are used. When nickel sulfate or sulfamate salts are used, amounts typically range from 40 to about 300 g/(calculated as nickel sulfate hexahydrate). Nickel chloride is also used and can be used. Usually about 40
It is used in an amount of from about 250g/ to about 250g/. The introduced chloride or halide ions impart favorable electrical conductivity to the bath and at the same time increase the corrosion resistance of the soluble anode.

Iron compounds consist of inorganic ferrous salts such as ferrous sulfate and ferrous chloride. Such ferrous salts are usually used in amounts of about 2 to about 60 g/g. Additionally, other bath-soluble and compatible iron ions such as soluble ferrous borofluorides, sulfamates, and the like may also be used.

The concentration of nickel and iron ions in the bath is controlled such that the weight ratio of nickel to iron ranges from about 5:1 to about 50:1. The nickel ion concentration is at least about 10 g/l and the iron ion concentration is at least about 0.2 g/l, although specific amounts can be controlled to achieve the appropriate weight ratios mentioned above.

To maintain the ferrous and ferric iron in solution, an iron solubilizer is used in an amount that maintains a preferred concentration in the bath in a form that allows electrodeposition onto fabrics. The solubilizer maintains iron ions in solution through its complexing function and/or by reducing ferric iron to ferrous iron and preventing precipitation of ferric hydroxide. The iron solubilizer can be any conventionally used in the industry, typically ascorbic acid, isoascorbic acid, oxalic acid, malic acid, glutaric acid, gluconic acid, muconic acid, glucoheptonic acid, glycolic acid, 2 to 11 carbon atoms, 1 to 6 hydroxyl groups and 1 to 3 carboxylic acid groups, such as tartaric acid and its analogues and their nickel and iron salts and their water-soluble and bath-compatible salts such as ammonium and alkali metals; It consists of a hydroxyl-substituted lower aliphatic carboxylic acid having .

Usually the iron solubilizer is used in an amount of about 5 to about 100 g/, preferably about 10 to about 30 g/. Generally, concentrations of iron solubilizers greater than about 50 g/m are not necessary and in some cases are undesirable since they may generate organic deterioration products during long-term operation of the bath. Such a high concentration is also undesirable from an economic standpoint.
The iron solubilizer to iron concentration ratio in the bath is approximately 1:1 to
Preferably, the ratio is within the range of 20:1. 1:1
At ratios below, the iron component precipitates, and at ratios above about 20:1, an excess of solubilizer is present, resulting in the disadvantages and shortcomings mentioned above.

Further essential components constituting this bath are buffering agents such as boric acid, acetic acid and others as well as alkali metals thereof, ammonium nickel and its iron salts and other bath-soluble and bath-compatible salts and mixtures thereof. . This buffer is usually about 20 to about 60
g/, preferably from about 40 to about 50 g/. Particularly good results are obtained with boric acid and its bath-soluble salts.

This bath furthermore uses as its essential component a certain amount of a first class brightener or a so-called carrier brightener, preferably together with a second class brightener, to produce a coating which has particularly high gloss and excellent smoothness with respect to nickel-iron coatings. It is something that can be used. This first class brightener usually has approx.
It is used in an amount of 0.5 to about 20 g/, preferably about 2 to about 8 g/. When a second class brightener is used, it is usually about 0.25 mg/ to about 1 g/,
Preferably, it is used in an amount of about 10 to about 100 mg/. If an acid is included, the first and second class brighteners may be added to the bath in the form of the acid itself or as a salt with bath-soluble cations such as alkali metal ions, including ammonium.

Preferred first class brighteners are those described in US Pat. No. 3,974,044, which are incorporated herein by reference. The first class of brighteners as described in the above-mentioned patents consist of sulfo-oxygen compounds of sulfur-containing compounds as described in "Modern Electroplating" published by John Wiley and Sons, 2nd edition, page 272. Such first class brighteners include saccharin, sulfobenzaldehyde, benzenesulfamide, sodium allylsulfonate and the like, and mixtures thereof. Other bath-soluble sulfo-oxygen compounds are unsaturated aliphatic sulfonic acids, monocyclic and bicyclic aromatic sulfonic acids, monocyclic aromatic sulfone-amides and sulfonimides, and the like. Among the above, sacculin by itself or in combination with allylsulfonate and/or vinylsulfonate is a preferred first class brightener.

Preferred second class brighteners include acetylenic nickel brighteners such as acetylenic sulfo-oxygen compounds and acetylenic nickel brighteners such as propargyl alcohol, butyne diol and the like as described in U.S. Pat. No. 3,366,667. Includes acetylenic nickel brighteners such as polyethers derived from the condensation reaction of alcohols and diols with lower alkylene oxides such as epichlorohydrin, ethylene oxide, propylene oxide and the like.

Suitable and preferred additional type 2 brighteners include nitrogen-containing heterocyclic quaternary or betaine based nickel brighteners, typically used in amounts of about 1 to about 150 mg/ml. A preferred compound of this type is described in U.S. Pat. No. 2,647,866, and this nitrogen-containing heterocyclic sulfonate is described in U.S. Pat. No. 3,023,151.
It is listed in the issue. Preferred compounds described herein are quaternary compounds of pyridine or betaines or sulfobetaines of pyridine. Preferred quaternary compounds to be used are quinaldine propane sultone, quinaldine dimethyl sulfate, quinaldine allyl bromide, pyridine allyl bromide, isoquinaldine propane sultone, isoquinaldine dimethyl sulfate, isoquinaldine allyl Bromide and its analogues.

In addition, second class brighteners also include the reaction product of a polyamine type brightener having a molecular weight of 300 to about 24,000 and an alkylating agent of the type described in U.S. Pat. No. 4,002,543. Alkylating agents include dimethyl sulfate, acetic chloride, allyl bromide, propane sultone, benzyl chloride or propargyl bromide. The polyamine brighteners can be sulfonated using sulfamic acids, chlorinated sulfonic acids, and the like. The ratio of polyamine to alkylating or sulfonating agent may be varied such that not all amino groups necessarily need to be alkylated or sulfonated.

In addition to the required Type 1 and optional Type 2 brighteners and other bath components, further optional additives may consist of special carrier agents of the type described in U.S. Pat. No. 3,806,429. I quote this substance here. Such optional special additives are not necessarily necessary for the method according to the invention to achieve particularly good gloss and high degree of smoothness, but they may be included in the bath. When exposed to extremely low current densities, a shiny nickel-iron film typically forms over the entire surface of the fabric. Such special additives consist of organic sulfides and are commonly used in the range of about 0.5 to about 40 mg/g/, and have the following general formula: [Here, R ₁ is hydrogen, carbon, or organic radical,
R ₂ is nitrogen or a carbon atom of an organic radical,
R ₃ is a carbon atom of an organic radical]. R ₁ and R ₂ or R ₃ may be bonded together through a single organic radical.

Typically the bath soluble organic sulfides are 2-aminothiazole and isothiourea. 2-aminothiazole and 2-aminobenzothiazole are ethanesulfonate bromide, propane sultone,
It may be reacted with benzyl chloride, dimethyl sulfate, diethyl sulfate, methyl bromide, propargyl bromide, ethylene dibromide, allyl bromide, methyl chloroacetate, sulfophenoxyethylene bromide to form compounds suitable for use. 2-amino-5-chlorothiazole,
Substituted 2-aminothiazoles and 2-aminobenzothiazoles such as 2-amino-4-methylthiazole can also be used. Thiourea can be reacted with propiolactone, butyllactone, chloroacetic acid, chlorpropionic acid, propanesultone, dimethyl sulfate, and the like. Also phenylthiourea, methylthiourea, allylthiourea,
and other similar substituted thioureas can also be used to form preferred reactive compounds.

The bath further contains as an essential component hydrogen ions to provide a pH of about 2.6 to about 4.5, preferably about 3.2 to about 3.8. As the hydrogen ion, any acid commonly used in nickel-iron plating baths may be used, but sulfuric acid and hydrochloric acid are preferred.

The bath may further optionally contain an amount of reducing saccharide. According to the present invention, monosaccharides or disaccharides are preferably used as the reducible saccharides or mixtures of saccharides. Monosaccharides are polyhydroxy aldehydes or polyhydroxy ketones having at least 3 aliphatic carbon atoms. The simplest monosaccharides are glyceraldehyde (common name aldose) and dihydroxyacetone (ketose). Other preferred monosaccharides include dextrose, sorbose, fructose, xylose, erythrose and arabinose. Disatucaride is a glucoside derivative of monosaccharide, in which one sugar forms a glucoside with the hydroxyl group of another sugar. Disactucharides useful in the practice of the invention include lactose, maltose, and turanose. Other disaccharides are also available where the second monosaccharide has an at least temporarily free carbonyl group. When reducing saccharides are used, amounts in the range of about 1 to about 50 g/, preferably about 2 to about 5 g/ are used. Reducing saccharides function as weak reducing agents for ferric iron in the bath, but when used with tartrate-type complexing agents and Type 1 and Type 2 brighteners, they exhibit a synergistic effect to improve the performance of nickel-iron electroplating. It significantly increases gloss and smoothness, but this effect has not been fully understood to date.

Additionally, bath-soluble and compatible salts thereof, such as ascorbic acid and/or isoascorbic acid and alkali metal salts, are added to stabilize the iron ions in the ferrous state. When ascorbic acid and/or isoascorbic acid is used as the sole iron solubilizer, it is used in an amount of about 100g/or less.
Preferably, when this stabilizer is used in conjunction with other iron solubilizers such as those described above, from 0.5 to about 3
g/, preferably from about 1 to about 2 g/.

The use of reducing saccharides and/or stabilizers inhibits the oxidation of ferrous salts used initially in bath preparation to form ferric ions during bath operation. The rate of production of ferric ions is related to the area of the anode where oxidation occurs, and also to the oxidation when air agitation is used. Generally, it is preferable to control the ferric ion concentration to about 40% or less of the total iron content.

According to the method of this invention, the fabric to be plated is immersed in a plating bath and used as a cathode for about 5 to 50 minutes.
Average current density of 100 ASF (0.5 to 10.8 A/Dm ² ), preferably about 30 to about 60 ASF (3.0 to
6.0 A/Dm ² ) over a period of time that provides the desired plating thickness. Typically for decorative purposes it will range from about 0.1 mil to about 2 mil, preferably from about 0.2 mil to about 0.5 mil. Usually the bath temperature is maintained between 105°C (41°C) and about 180°C (82°C), preferably between about 130°C (55°C) and about 140°C (60°C). The plating time is usually preferably about 5 minutes to 30 minutes, taking into account the current density used and the desired plating thickness. Although agitation of the bath during plating is not necessary, conventional agitation means such as mechanical agitation, air agitation and others are preferably employed.

EXAMPLES Examples will now be given to further illustrate the plating bath and method according to the present invention. It will be appreciated that these examples are for illustrative purposes only and are in no way intended to limit the scope of the invention as described herein and as claimed.

Example 1 A nickel _- iron electroplating bath was prepared with the following composition: Component concentration NiSO4.6H2O _150g / _{NiCl2.6H2O 75g / H3BO3 50g} / _FeSO4.7H2 O 40g/ Sodium gluconate 20g/ First class brightener 7g/ Second class brightener 20mg/ This sodium gluconate is an iron solubilizer. This first class brightener consisted of a mixture of sulfo-oxygen type carrier brighteners consisting of 2.5 g/g of saccharin and 4.5 g/g of sodium allyl sulfonate. The second type brightener consists of propinoxyethylene oxide, which is the reaction product of polyethyleneimine (molecular weight 1200), sulfamic acid, and 2-aminothiazole. Increase the bath temperature to 140〓(60
°C) and the pH of the bath was adjusted to 3.5. A clean rolled steel plate was plated at 30 ASF (3.0 A/Dm ² ) for 10 minutes, but the resulting film was glossy, but had dark pits and white spots throughout the medium current density region. . The concentrations of the bath components were deliberately selected to yield undesirable coatings such as high iron containing alloys, such as those containing approximately 42.5% iron.

Example 2 The nickel-iron electroplating bath of Example 1 was refilled to have the same bath composition and an additional 5 mg of propargyl sulfonate were added. When a clean rolled steel plate test piece was plated under exactly the same conditions as in Example 1, the entire surface, including the recessed areas, was shiny and the white spots had disappeared.

Example 3 A nickel-iron plating solution that has been in commercial operation for about one year was analyzed and found to have the following composition.

Ni ⁺² 73.75g / NiSO ₄・6H ₂ O 187.50g / NiCl ₂・6H ₂ O 138.85g / H ₃ BO ₃ 44.24g / Stabilizer* 17.40g / Fe ⁺² 2.67g / Fe ⁺³ 1.61g / 1st class brightener 3.8% 2nd class brightener 2.3% PH 3.1 *Calculated as tartaric acid, consisting of a mixture containing 65% tartaric acid, 15% lactose and 20% by weight of isoascorbic acid, which were initially added to the bath.

A 3″ x 5″ clean polished brass test plate was placed in the plating solution described above using a standard Hull Cell apparatus.
Plating was carried out for 10 minutes at 2AMPS and 140°C (60°C). The resulting film was glossy over the entire surface, and no clouding was observed over the entire surface of the test piece.

EXAMPLE 4 The Hull cell test was repeated with a fresh sample of the nickel-iron plating solution of Example 3 with a pH of 3.5 and an increased iron content of 5.0 g/l. The resulting film had a glossy appearance in the high current density area, a white smoky haze in the medium current density area, and a dark, blotchy gray color in the low current density area.

Example 5 The pH of a fresh sample of the nickel-iron plating solution of Example 3 was increased again to 3.5 and the iron content was reduced to 5.0 g/
and then 5 mg/ml of propargyl sulfonate was added. When the Hull cell test was repeated, the resulting film was generally glossy and there was no clouding over all the test pieces.

Example 6 The pH of the solution of Example 5 was further increased to 3.8, brightener and iron were supplemented, and the Hull Cell test was repeated.
After plating at 2AMPS for 10 minutes, the resulting film was similar to the test piece described in Example 4, but the degree of haze and darkness was not so significant, especially in the middle current density area.

Example 7 5 g of propargyl sulfonate was further added to the nickel-iron solution described in Example 6, the brightener and iron were supplemented, and the Hull Cell test was repeated as in the previous example. The resulting film was glossy over the entire surface and had no cloudiness.

Example 8 The commercial nickel-iron plating bath described in Example 3 was charged into a standard Hull cell equipped with an agitator. Increase bath pH to 3.8 and total iron content to 5.0g/
increased to Hull cell test piece 2AMPS, 145〓
(63°C) for 10 minutes. The produced film was glossy in the high current density region, had a gray appearance with a markedly smoky appearance in the medium current density region, and was dark in color in the low current density region.

Example 9 15 mg of sodium 1-butyne-3-sulfonate was added to the bath described in Example 8 to replenish the brightener and iron and the Hull Cell test was repeated. There was a slight reduction in haze in the medium current density region and some improvement in the properties of the resulting film.

Example 10 The Hull Cell test was repeated with the concentration of sodium 1-butyne-3-sulfonate described in Example 9 increased to 60 mg/2, supplemented with brightener and iron.
The resulting film was generally glossy and smooth over the entire surface, but very slight clouding was observed along the meniscus.

Example 11 The commercial plating baths specified in Examples 3 and 8 were again used to test the effect of 1-pentyne-5-sulfonic acid. The initial test specimen without the addition of the test substance was identical to that described in Example 8.
Sodium 1-pentyne-5-sulfonate 50mg/
A Hull cell test was conducted by adding brighteners and supplementing iron. The resulting film was generally glossy and smooth over the entire surface of the test piece, including the meniscus.

Example 12 The commercial plating bath specifically described in Examples 3 and 8 was again used to test the effectiveness of sodium 3-heptyne-7-sulfonate. The structure of this compound is outside the range of useful compounds encompassed in the generic structural formula above and is as follows: _CH3 - _CH2 -C≡C- _CH2 - _CH2 - _CH2 - _SO3. Na The initial test specimen without the addition of this test substance was exactly the same as described in Example 8.
After adding 50 mg of the above-mentioned heptine derivative and supplementing the brightener and iron, a Hull cell test was conducted, but no improvement in the formed film was observed.

Example 3 The Hull Cell test was repeated after increasing the concentration of the sodium 3-heptyne-7-sulfonate to 100 mg/1 and supplementing with brightener and iron. No improvement was observed in the formed film, and the cloudiness in the medium current density region worsened, and the dark color in the depressed areas became even deeper.

Although the preferred embodiments disclosed by this invention are sufficient to accomplish the objects set forth above, changes, changes, and modifications may be made without departing from the spirit and scope of this invention as set forth in the claims. It is possible.

Claims (1)

[Scope of Claims] 1. Nickel ions, iron ions, an iron solubilizer in an amount to maintain the iron ions at a preferred concentration in solution, a buffering agent, and an amount of iron ion in an amount sufficient to produce a bright nickel-iron film. A kind of brightener, the pH of the bath is 2.6 or more
4.5 hydrogen ions present in at least 2 mg/amount and having the following structural formula: i.e. [Here, R is H or an alkyl group having 1 to 4 carbon atoms, n is an integer of 0 to 4, m is an integer of 0 to 1, and X is H, NH ₄ , or bath-soluble An aqueous plating bath comprising a bath-soluble additive or a mixture thereof, which is a metal and is suitable for electrodepositing a nickel-iron alloy film having gloss and excellent smoothness. . 2. The plating bath according to claim 1, wherein X is H, NH ₄ and an alkali metal. 3. A plating bath according to claim 1, characterized in that the additive is contained in an amount of 2 to 300 mg/. 4. A plating bath according to claim 1, characterized in that the additive is contained in an amount of 5 to 80 mg/. 5 The nickel ion is contained in an amount of at least 10 g/, and the iron ion is contained in an amount of at least 0.2
2. A plating bath according to claim 1, characterized in that the plating bath is contained in an amount of 1.5 g/g/g and the weight ratio of nickel ions to iron ions is in the range of 5:1 to 50:1. 6. The plating bath according to claim 1, wherein the hydrogen ions are contained to give a pH of 3.2 to 3.8. 7. A plating bath according to claim 1, characterized in that the buffering agent is selected from the group consisting of boric acid, acetic acid and bath-compatible and soluble salts thereof and mixtures thereof. 8. A plating bath according to claim 1, characterized in that the iron solubilizer is contained in an amount of 5 to 100 g/l. 9. The plating bath according to claim 1, characterized in that the iron solubilizer is contained in an amount of 10 to 30 g/l. 10 nickel ion, iron ion, iron solubilizer in an amount that maintains iron ion at a preferred concentration in solution;
a buffering agent, a first class brightener sufficient to produce a bright nickel-iron film, hydrogen ions capable of bringing the pH of the bath from 2.6 to 4.5, and at least 2 mg
present in the following structural formula: i.e. [Here, R is H or an alkyl group having 1 to 4 carbon atoms, n is an integer of 0 to 4, m is an integer of 0 to 1, and X is H, NH ₄ , or bath-soluble an aqueous plating bath consisting of a bath-soluble additive or a mixture thereof, which is a metal;
A bright nickel-iron alloy electroplating bath characterized in that it is contained in an amount of . 11 The iron solubilizer consists of a hydroxyl-substituted lower aliphatic carboxylic acid having 2 to 11 carbon atoms, 1 to 6 hydroxyl groups, and 1 to 3 carboxyl groups, bath-soluble and compatible salts thereof, and mixtures thereof. Claim 10 is characterized in that
Plating bath described in section. 12. Claim 10, characterized in that the iron solubilizer consists of an acid selected from the class consisting of ascorbic acid and isoascorbic acid and bath-soluble and compatible salts thereof. The described plating bath. 13. The plating bath according to claim 10, wherein the iron solubilizer contains a reducing saccharide. 14 The iron solubilizer is tartaric acid, ascorbic acid,
Consists of at least one acid selected from the group consisting of isoascorbic acid, gluconic acid, citric acid, glucoheptonic acid, malic acid, glutaric acid, muconic acid, glycolic acid, and bath-soluble salts thereof and mixtures thereof. The plating bath according to claim 10, characterized in that: 15. A plating bath according to claim 10, characterized in that the bath-soluble additive comprises 1-butene-3-sulfonic acid and bath-compatible and soluble salts thereof. 16. A plating bath according to claim 10, characterized in that the bath-soluble additive comprises 1-pentene-5-sulfonic acid and bath-soluble and compatible salts thereof. 17. A plating bath according to claim 10, characterized in that the bath-soluble additive comprises propargyl sulfonic acid and bath-soluble and compatible salts thereof. 18. The plating bath according to claim 17, wherein the compatible salts of propargyl sulfonic acid consist of alkali metal and ammonium salts. 19 Claim 1, characterized in that the additive is contained in an amount of 2 to 200 mg/
The plating bath described in item 7. 20 Claim 17, characterized in that the additive is included in an amount of 5 to 40 mg/
Plating bath described in section. 21 A method of electrodepositing a nickel-iron alloy film having gloss and excellent smoothness on a conductive fabric, the fabric containing nickel ions, iron ions, and iron ions in an amount that maintains the desired concentration in solution. an iron solubilizer, a buffering agent, a first class brightener in an amount sufficient to produce a bright nickel-iron film, and a pH of the bath.
2.6 to 4.5 hydrogen ions and at least 2
mg/amount and has the following structural formula: i.e. [Here, R is H or an alkyl group having 1 to 4 carbon atoms, n is an integer of 0 to 4, m is an integer of 0 to 1, and X is H, NH ₄ , or bath-soluble A process of immersing the fabric in an aqueous plating bath consisting of a bath-soluble additive or a mixture thereof shown in [Is a metal], a process of effectively forming a nickel-iron film thereon using the fabric as a cathode, and a process of adjusting the bath temperature. 105 to 180〓(41
and continuing the electrodeposition of the nickel-iron plating until the desired thickness is obtained.