JP2607681B2 - Composite plating method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a composite plating method for producing a Co-coated base material in which alumina and other inorganic particles are uniformly dispersed.

[Conventional technology]

The composite plating method has attracted attention because it can add new functions such as abrasion resistance, self-lubricating property and corrosion resistance by uniformly dispersing inorganic particles in a conventional metal plating coating. The method of simultaneously combining a plurality of dispersed inorganic particles is considered to be indispensable for the production of a material under a special environment in the future.

[Problems to be solved by the invention]

Conventionally, an example of dispersing and compounding a single inorganic powder particle in a metal matrix is disclosed in Japanese Patent Publication No. 50-21297, Japanese Patent Publication No. 58-24516,
Although many are found in each publication such as JP-A-53-142330, there is almost no example in which a plurality of inorganic powder particles are simultaneously compounded. This is because the surface electrical properties in the plating bath vary depending on the type of the inorganic particles, and the particles are selectively composited with the metal matrix.

The present invention has been made in view of the above-mentioned state of the art, and aims to provide a method capable of obtaining a composite plating in which a plurality of inorganic particles in a matrix metal are uniformly dispersed.

[Means for solving the problem]

The present invention, in a Co electroplating bath, dispersed silane-coupled alumina, and at least one or more inorganic particles powder, a cationic or a cationic surfactant in the plating bath 0.01 to 5.0 wt% % Is a composite plating method characterized in that plating is performed by adding%.

In the embodiment of the present invention, in a preferred embodiment, boron nitride is used as the other inorganic particles in the above configuration.

That is, in dispersing alumina and at least one or more inorganic particles in a cobalt electroplating bath according to the present invention, first, alumina is subjected to a silane coupling treatment.
Examples of the silane coupling agent include alkoxyalkylsilanes such as a methoxy group and an ethoxy group, but other silane coupling agents may be used. Next, silane-coupled alumina and at least one or more other inorganic particles are dispersed in a cobalt electroplating bath, and the following surfactant is added in an amount of 0.01 to 5.0% by weight, preferably 0.1 to 1.0% by weight.
Weight percent, and after sufficient dispersion, electroplating,
In this method, alumina and inorganic particles are uniformly dispersed in the cobalt plating coating.

As the type of the surfactant, (i) an aliphatic amine salt and a quaternary ammonium salt thereof, for example, a primary amine having 6 to 20 carbon atoms, a secondary amine,
Examples include tertiary amines, diamines, triamines, polyamines and their acetates, oleates, hydrochlorides, and the like. In addition, (ii) aromatic quaternary ammonium salts such as pyridinium salts, and (iii) heterocyclic quaternary ammonium salts such as imidazolinium salts are also effective.

On the other hand, surfactants which are cationic in the plating bath, ie, exhibit a positive charge, include (iv) alkyl betaines such as carboxybetaine and sulfobetaine, and (v) amine oxides (vi) amphoteric surfactants such as imidazoline derivatives. No. Furthermore, it was found that (vii) polyalkylene oxide adducts containing aliphatic amines (viii) alkylene oxide adducts of polyvalent amines having a plurality of active hydrogens such as ethylenediamine, tetraethylenediamine, and polyethyleneimine are also effective. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

It has been found that the above surfactants are effective even if they are used in combination of a plurality thereof.

As the plural kinds of inorganic particles, boron nitride and alumina,
Molybdenum disulfide and alumina, graphite and alumina, etc. may be mentioned, but there is no problem even if two or more kinds are used.

[Action]

As a mechanism of incorporating inorganic particles into the metal matrix in the composite plating method, transport of the particles to the plating surface by mechanical stirring of the plating bath, adsorption of the particles to the plating surface, and entrapment of the particles by the precipitated metal can be considered. In reality, there is no doubt that will have a big impact,
Undoubtedly affects the composite of the particles into the metal matrix. In the present invention, since the surface of the inorganic particles is positively charged by adsorbing the surfactant to the surface of the inorganic particles, it is possible to migrate the cobalt ions to the cathode and to transfer and complex the particles to the metal matrix. At that time, it is important to select a surfactant that makes a plurality of types of inorganic particles have the same surface potential.

However, if the surface potentials of the particles are significantly different, it may be difficult to select a surfactant, and a method of changing the surface potential of one of the particles may be considered. In the present invention, the surface potential of alumina having a high surface potential is reduced by subjecting the surface of the alumina to a silane coupling treatment, and then the surface potential of a plurality of particles is made substantially the same by adding a surfactant.

Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

〔Example〕

The present invention was carried out under the following conditions. That is, the plating solution was prepared to a standard composition of 500 g / l of cobalt sulfate, 17 g / l of sodium chloride, and 60 g / l of boric acid, and particles and a surfactant were charged into a stirable plating bath. 40
° C., was electroplated under the conditions of a current density of 3A / dm ^2. Table 1 shows the properties of the inorganic particles used.

The surface of the alumina particles used in the present invention was subjected to silane coupling treatment by heat treatment with trimethylmethoxysilane before being added to the plating bath. The amount of eutectoid on the metal matrix after electroplating was determined using gravimetric analysis and an electron microscope.

Examples-1 to 19 A surfactant was used for alumina and boron nitride.
5 wt% was added. Table 2 shows the results.

Examples 21 to 25 In Example 1, the amount of the surfactant added was 0.01 to 5.0 wt.
%. Table 3 shows the results.

In addition, Example-20 is blank data when no surfactant was added, and it can be seen that both particles had poor composite.

As is clear from the examples, it was found that alumina and boron nitride were sufficiently eutectoid in the cobalt metal matrix, although the amount of the surfactant used in the present invention was small.

[Effects of the Invention] In the present invention, the silane-coupled alumina and other one or more inorganic particles are eutectoidized and complexed in the cobalt metal coating, so that abrasion resistance and self-lubricating property which were not obtained conventionally can be obtained. It became possible to add functions at the same time.

Claims (2)

(57) [Claims] In a Co electroplating bath, silane-coupled alumina and at least one or more other inorganic particle powders are dispersed, and a cationic surfactant or a surfactant exhibiting cationicity in the plating bath is used in an amount of 0.01 to 10%. A composite plating method characterized by plating by adding 5.0% by weight. 2. The composite plating method according to claim 1, wherein the other inorganic particle powder is boron nitride.