JPH02310376A - Formation of metallic coating film on electrically nonconductive body - Google Patents

Abstract

PURPOSE:To form a metallic coating film adhering tightly to the surface of an electrically nonconductive body by using a palladium soln. contg. palladous amine chloride, pyridinesulfonic acid and a water soluble lanthanide salt and a reducing agent when the nonconductive body is chemically plated. CONSTITUTION:The surface of an electrically nonconductive body such as ceramics is pretreated by etching with a phosphoric acid soln. and nucleus formation treatment with a palladium soln., chemical electrodeposition is carried out while carrying out chemical plating and then electroplating is further carried out to form a metallic coating film. When the chemical plating is carried out, a palladium soln. contg. 1.50 g/l (expressed in terms of Pd) palladous amine chloride, 0.5-30g/l pyridinesulfonic acid or salt thereof and 0.1-100ppm (expressed in terms of lanthanide) water soluble lanthanide salt such as cerium sulfate and sodium borohydride as a reducing agent are used. The metallic coating film is formed with tight adhesion to the surface of the nonconductive body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of forming a metallic coating on a non-conductive material.

[Conventional technology]

The method of applying electroless plating to a non-conductive material to generate a metal film has been used for a long time, but there are not many methods to strengthen the adhesion between the film and the non-conductive material. had not been developed. Usually, when plating a metal film on a non-conductive object, electroless plating is performed to impart conductivity to the surface of the non-conductive object, and then electrolytic plating is applied to obtain the required mechanical strength.

[Problem to be solved by the invention]

However, if the metal film formed by electroless plating is weak, no matter how strong the formed film obtained by electrolytic plating on its surface is, the metal formed film as a whole will be weak. Conversely, no matter how strong the film produced by electroless plating is, if the film obtained by electrolytic plating is fragile, the entire metal produced film system will also be weak.

When trying to generate a strong metal film on a non-conductive object, each metal film forming system must maintain an appropriate combination for the overall mechanical strength and mutually reinforce each other to achieve the purpose. cannot be reached.

[Means to solve the problem]

Therefore, we took up the case where a metal film B is formed on the surface A of a non-conductive object, and examined the conditions for A to adhere firmly to B and B to A, and found that the following conditions This was revealed through experiments.

In other words, the conditions are: ■ Form a surface that allows B to adhere firmly to A; ■
Treat A so that B can easily attach to it, ■ Make sure that B reaches every corner of A, ■ Make B even stronger when it lacks the mechanical strength of A, and so on. can be expressed using the following general technical process name.

■ Pre-etching A.

■ Perform nucleation pretreatment of B on A.

■ Perform chemical plating and chemical electrodeposition of B on A.

■ Perform strain-free metal electrodeposition (electrolytic plating) of B on A.

We have come to propose this invention based on the knowledge that by performing these four treatments, the adhesion of the metallic film formed on the surface of a non-conductive object can be reliably and stably improved. This is what happened.

Specifically, in this invention, when forming a metallic film on a non-conductive object, the surface of the non-conductive object is subjected to etching treatment and nucleation treatment as pretreatment, and then chemical plating is performed. A method of forming a metallic film on a non-conductive object by chemical electrodeposition and electrolytic plating. or its salt as 0.5-30 g/l, and the soluble salt of lanthanide metal as the amount of lanthanide metal. 1-100p, p, m.
(Claim 1) A palladium solution containing a reducing agent and a reducing agent are used.

[Effect]

First, in the present invention, as a "non-conductive substance", we start with dentin, which is a mixture of inorganic and organic substances, whose adhesion is least likely to improve even when electroless plating is applied, and inorganic ceramics, glass, and mixtures thereof. The present invention can be applied to certain glass ceramics, organic plastics, laminates thereof, etc. (Claims 6 and 7).

Pretreatment is performed on the surface of such a non-conductive material. The "pretreatment" is intended to include etching treatment and nucleation treatment (claim 1). Etching treatment is a process in which corrosion holes are created using a chemically corrosive material on the surface of a non-conductive material to increase the surface area, with the hope of adsorption and mating effects.For dentin, it is preferable to use a phosphoric acid solution. (Claim 2) Preferably, HF-based materials are used for ceramics, and NaOH-based materials are preferred for glass. In any case, the adhesion of the metallic film is greatly influenced by the selection of the etching material and the setting of the etching time, so it should be selected appropriately in accordance with the type of non-conductive material.

The nucleation treatment is to make the subsequent chemical electrodeposition more effective, and it improves the adsorption, reduction, wettability, and activation of metal ions, preferably palladium ions (claim 3), by making them non-conductive. carried out over the entire intended surface of the object,
The final step is to generate palladium nuclei.

"Chemical plating and chemical electrodeposition" involves supplying a palladium solution containing concentrated metal ions, preferably palladium ions, to the surface of a non-conductive material prepared by pre-treatment, and building a conductive film through chemical plating. When the current necessary for electrodeposition can be applied, electrolytic electrodeposition is performed using the solution, and the resulting metal film is strengthened by transitioning from chemical reduction to electrolytic reduction (Claim 1) . For these chemical plating and chemical electrodeposition, a specially prepared palladium solution and reducing agent are used (Claim 1). The specially prepared palladium solution contains palladium chloride in an amount of 1-50 g/l and pyridine sulfonic acid or its salt in an amount of 0.0 g/l. 5-30 g/It,
The lanthanide metal content of the soluble salt of the lanthanide metal is 0.1-100 p, p, m. , including.

As the reducing agent, sodium borohydride, lithium aluminum hydride, hydrogen iodide, sodium thiosulfate, sodium hypophosphite, etc. can be used.

Furthermore, when performing chemical plating and chemical electrodeposition using such a special palladium solution and reducing agent, the surface of the non-conductive object coated with the palladium solution and reducing agent is forcibly coated with a metal or non-metallic material. It is preferable to use friction (claim 4). When rubbed, it is expected that the energy given by the friction will form a collection of chemically precipitated atoms into a metallic state, making the chemically deposited film stronger.

For electrolytic plating, which is performed as a final treatment, the metal is selected according to the purpose of metallizing non-conductive materials. For example, if a palladium metal coating is required, palladium is used, or for aesthetics. If necessary, gold, silver, or platinum may be used, or base metals may be used for adhesive properties.

The above-mentioned special palladium solution is a low-stress solution, has a high palladium concentration, can perform high-speed plating processing, and is suitable for forming a thick palladium film. Particularly preferred is a palladium-nickel plating solution. Further, as the soluble salt of the lanthanide metal, it is preferable to use at least one selected from cerium sulfates, nitrates, acetates, oxalates, bromides, and chlorides (Claim 5).

Furthermore, if diamond is selected as a non-conductive material and a palladium film is formed as a metal film on the back side,
Optical properties such as light transmittance and/or reflection can be controlled by the palladium coating formed on the surface (
Claim 8).

In addition, when CMP glass ceramic is selected as the non-conductive material, optical properties such as light transmittance and/or reflection can be similarly controlled by a metallic coating formed on its surface (Claim 9). ).

Further, electrolytic tin plating can be applied to the surface of the metal coating of white metal (Claim IO), and when electrolytic tin plating is performed by rubbing the surface of the metal coating of white metal, This can be expected to improve adhesion (Claim 11).

〔Example〕

Big Dust Crab In this example, we selected a dentin material that is said to have the poorest adhesion as a non-conductive material, and investigated how well the metal coating formed on it could achieve adhesion. This indicates whether or not the metallic coating was formed in good condition.

Adhesion when bonded to dentin material using existing adhesives is generally around 50 kg/c IIr, but by applying the above treatment to dentin, it can be increased to 100 kg/c IIr.
It is known that a degree of adhesion can be obtained.

However, there are no examples of electroless plating. Therefore, when the above-mentioned (■) of this invention was applied directly to dentin material, 15
It was possible to improve the adhesion to about 0 kg/cnr. Also, if you do ■10■...170 kg/
crl, ■+■+■ 190 kg/car
l Then, if you do ■＋■＋■＋■, 200 kg/
It was possible to obtain adhesion strength of cr1 or higher.

Here, the technical contents of (1), (2), (2), and (3) are either new or have been further improved from the conventional technology, and their characteristics will be explained below. Conventional electroless plating technology generally consisted of chemical plating and electrodeposition similar to (2), but in this example, a corrosion-resistant precious metal was used for the metal coating in consideration of water resistance. Palladium was selected because of its large catalytic ability. Conventionally, a conductive film was created by chemical plating, and then strong noble metal electrodeposition was performed on the film, but in this example, chemical plating of palladium was followed by palladium electrodeposition. A new technique called chemical electrodeposition was employed. This resulted in much improved adhesion compared to conventional electroless plating.

Furthermore, in this example, three other types of treatments were added, so that the adhesion was significantly enhanced.

Next, we improved the adhesion of chemical electrodeposition that produced palladium nuclei. In this treatment method, palladium nuclei are generated in dentin as a pretreatment prior to chemical electrodeposition in order to efficiently perform chemical plating of palladium. If palladium nuclei are generated and activated in the dentin in advance, the palladium ions in the catalyst react with the palladium nuclei and become fixed, increasing adhesion.

Next, if such a reaction occurs uniformly over a given area of dentin, increasing the area of dentin by etching in advance can be considered a treatment method sufficient to achieve the objective.

This is the etching process (■). This etching treatment is meaningless if it merely increases the area but does not provide mechanical strength. This is done by considering the physical properties of dentin, and in addition to increasing the area due to the unevenness, each of the unevenness is strong.
It is also desirable that the etching has a shape that can be expected to have an anchoring effect. Since dentin is apatite mainly composed of calcium phosphate, the purpose cannot be achieved with just an acidic solution, and the treatment is performed using an etching agent mainly composed of phosphoric acid and adjusting its action time.

In this way, the base was made considerably strong by the treatments (1), (2), and (2), but when viewed from the dentin as a whole, the metal strength at the outermost periphery may be insufficient. In such cases, mechanical strength is generally obtained by electrodepositing base metals, but such methods result in poor water resistance, corrosion, and cannot withstand many years of use. Therefore, in this embodiment, since noble metals were used from the inside, electrodeposition using noble metals should be selected for the outermost periphery as well. I would like to use gold or palladium for that purpose, but gold is a little soft. I would like to choose palladium, but this poses a problem.

It has come this far by stacking metal palladium,
It has been found that metallic palladium absorbs hydrogen and causes hydrogen embrittlement, making thick metal electrodeposition impossible. This time, we were able to solve the problem by using a strain-free electrodepositing solution of palladium, which is extremely slightly strained by hydrogen during electrodeposition.

Before explaining the test results, we will explain how to measure adhesion. The sample to be measured for adhesion was embedded in resin to make it easier to fix, and then a composite resin adhesive was applied to the object to be measured and a tensile shear test was conducted to examine adhesion. The adhesive strength between metals of composite resin is 300-400k
g/crl is available, so I used it.

The details of the sample are shown with reference to the drawings. 1 is an extracted human or bovine tooth with dentin, and the enamel has been removed and the surface has been exposed. 2 is a shearer made of stainless steel #304,
The size is 5φ×3, and the adhesive surface is sandblasted. 3 uses composite type Banavia EX (registered trademark, Kuraray product) as adhesive. Reference numeral 4 denotes an electrodeposited metal, which is palladium metal and has dimensions of 6φ and a thickness of about 5 to 10 μm. Reference numeral 5 denotes an embedding resin, which is made of polyester resin and has dimensions of 22φ x 15 to 30 mm.

Etching agents are Panavia (Kuraray product) with phosphoric acid (37wt%) and ferric chloride (3wt%) + citric acid (10wt%).
wt%) were used.

The test result resistance value (Ω) is the DC resistance value of the final electrodeposited palladium surface (in this case, strainless electrodeposition).
By measuring this value, the variation in the final metal film thickness can be estimated. Currently, the resistance is set at 1Ω or less at a distance of 3 mm, and the final electrodeposition must be performed until the value is below this value.

Kansei Shi 2 In this example, the adhesion between glass and ceramics was determined. Glass/ceramics have a composition of CaO:43
mo1%, PtOs: 54m01%+ A I! O
s: X mo 1%, and was fired at around 700°C. It is a highly aesthetic material that harmonizes with the color of human skin.The results of adhesion tests using eight types of glass ceramics as samples were as follows.

This example examines the adhesion of other materials.If the material is unsuitable for testing due to the shape and size of the material, or if no force is applied to the electrodeposited metal, I decided to just investigate whether electrodeposition is possible. The materials used and the quality of electrodeposition are shown below.

- Name of two companies 1 Etching agent l Ceramics for good or bad bases 5% HF Porcelain for good electrical use // // Naturally produced polished marble
NaOH good frosted glass 1/ //Left camera lens〃〃Bakelite plate Sandblasting〃Phenol plate
In this example, a CMP glass ceramic was selected as a non-conductive material, a palladium film was formed on its surface, and the adhesion strength between the ceramic and metal palladium was investigated by a tensile shear test. It is.

〔sample〕

Five samples Nα1-5 were prepared under the following conditions.

A cylindrical CMP glass ceramic with a diameter of 9 mm and a length of approximately 5 mm was selected, and for convenience in testing, a diameter of 22 mm was selected.
, embedded in polyester resin with a length of about 27 mm, and further N
A masking tape with a hole of 6 mm in diameter, which was made flat with O.600 abrasive paper, was applied to the center of the 9 mm ceramic, and all treatments were performed within this area.

[Etching treatment]

15 minutes with NaOH [Nucleation treatment] Using a palladium solution, treatment was performed twice in succession under the following conditions.

Immersion 1 minute Neogant B (Nippon Schering Co., Ltd. product) Activation 5 minutes Neogant 823 (Nippon Schering Co., Ltd. product) Reduction 2 minutes 5BH (sodium boron hydroxide) 1/10 [Chemical plating] As a special palladium solution, A solution having the following composition was used and stirred for 2 minutes.

Paradosammine chloride 40g (as metal palladium) Ammonia water 40ml1 Ammonium chloride 50gPyridine sulfonic acid 5g Water
900ml pH 7.0 As a reducing agent, the SBH powder was directly applied to the palladium solution and stirred for 1 minute.

[Chemical electrodeposition]

The same special palladium solution as above was used and stirred for 1 minute. 3V10-15mA reducing agent 5BH0,
Stirring treatment was performed for 5 minutes.

[Electrolytic plating]

Electrolytic plating was performed using the same special palladium solution as above, followed by stirring for 1 minute. Further, tin electroplating was carried out using the following tin plating solution at 3V and 10mA, followed by stirring for 2 minutes. 3V, 4-8mA tin plating solution stannous sulfate (as metal tin) 50g potassium citrate 200g water
850ml pH4
, 5 [Shearing element] 5 US-304 stainless steel 5 mm, single-sided sandblasting results are as shown in the following table.

The grade of finish was good, as all samples showed adhesion strength of 150 kg/cm or more based on the standard table for the quality of the electrodeposited surface.

Note that CMP glass ceramic has light transmittance and reflectivity, and the metal palladium thin film formed on its surface also has light transmittance and reflectivity, so these properties can be controlled and
It turned out that it can be used. Even when a metal film other than palladium is formed, the optical properties can be controlled within a certain range.

In this example, a denture was selected as a non-conductive material, a palladium coating was formed on its surface, and its cross section was examined using a microscopic photograph.

〔sample〕

Dentures [Etching treatment] NaOH for 15 minutes [Nucleation treatment] A palladium solution was used twice in succession under the following conditions.

Immersion 1 minute Neogant B (Nippon Schering Co., Ltd. product) Activation 5 minutes Neogant 823 (Nippon Schering Co., Ltd. product) Reduction 2 minutes SBH1/10 [Chemical plating] Using the same special palladium solution as in Example 4 above, 2
The mixture was stirred for several minutes.

Stirring treatment was performed for 5 BHI of reducing agent.

[Chemical electrodeposition]

Using the same special palladium urea complex solution as above,
The mixture was stirred for 1 minute. 3V, 10-5mA reducing agent SBHO, 5 minutes, stirring treatment was performed.

[Electrolytic plating]

The same special palladium solution as above was used and stirred for 1 minute. Stirring treatment was performed at 3V, 10mA, and tin for 2 minutes. The state of formation of the metal palladium coating formed on the surface of the denture under the above conditions of 3 V and 4-8 mA is shown in the micrograph (X 1000 times) in FIG. 4. It can be seen that a metal palladium coating is formed with a thickness of about 20 microns.

〔Effect of the invention〕

Since the present invention is as described above, it is possible to form a metallic film that firmly adheres to the surface of a non-conductive object, and has many advantages.

[Brief explanation of drawings]

Figure 1 is a plan view of the sample body, Figure 2 is a side view of the sample body shown in Figure 1, and Figure 3 is a side view of the sample body shown in Figure 1.
FIG. 4 is an enlarged side view of the close contact portion of the sample body shown in the figure, and FIG. 4 is a micrograph (x1000 magnification) showing a cross section of the non-conductive material on which a palladium coating was formed. ■ -・・Dentin 2−・−・Shearer 3−・・Adhesive 4−・Electrodeposited metal 5−・Embedding resin Figure 1 Figure 2 Figure 3 Procedure correction writing method) % formula % ■, Description of the case 1999 Patent Application No. 131617 2, Title of the invention Method for forming a metallic film on a non-conductive material 3, Person making the amendment Relationship with the case Patent applicant address: 105

Claims (1)

[Scope of Claims] (1) Non-conductive material in which the surface of a non-conductive material is subjected to etching treatment and nucleation treatment as pre-treatment, then chemical electrodeposition is performed while chemical plating is performed, and then electrolytic plating is applied. A method for forming a metallic film on an object, wherein the chemical plating is performed using palladium chloride in an amount of 1-5 palladium.
0g/l, pyridine sulfonic acid or its salt 0.5-3
0 g/l, 0.1-100 p. of lanthanide metal based on soluble salt of lanthanide metal. p. m. A method for forming a metallic film on a non-conductive object, characterized by using a palladium solution containing , and a reducing agent. (2) The method for forming a metallic film on a non-conductive object according to claim 1, wherein the etching treatment according to claim 1 uses a phosphoric acid solution. (3) The method for forming a metallic film on a non-conductive material according to claim 1 or 2, wherein the nucleation treatment according to claim 1 uses a palladium solution. (4) The above chemical plating uses palladium chloride in an amount of 1-50 g/l, pyridine sulfonic acid or its salt in an amount of 0.5-30 g/l, and a soluble salt of a lanthanide metal in an amount of lanthanide metal. as 0.1-
100p. p. m. The metallicity of a non-conductive object according to any one of claims 1 to 3 is carried out by forcibly rubbing the part coated with a palladium solution containing a reducing agent with a metal or a non-metallic object. How to form a film. (5) Claims 1 to 4, wherein the soluble salt of the lanthanide metal of Claim 1 is at least one selected from cerium sulfates, nitrates, acetates, oxalates, bromides, and chlorides. A method for forming a metallic film on a non-conductive object according to any one of the above. (6) Applying a metallic coating to the non-conductive material according to any one of claims 1 to 5, wherein the non-conductive material of claim 1 is an inorganic ceramic, a glass, or a glass ceramic that is a mixture thereof. Formation method. (7) The method for forming a metallic coating on a non-conductive material according to any one of claims 1 to 5, wherein the non-conductive material according to claim 1 is dentin which is a mixture of an inorganic substance and an organic substance. (8) The non-conductive substance according to claim 1 is diamond,
Forming a palladium coating as a metal coating on the back side,
A method for forming a metallic coating on a non-conductive object according to any one of claims 1 to 5. (9) Claim 1, wherein the non-conductive material of Claim 1 is a CMP glass ceramic, and optical properties such as light transmittance and/or reflection are controlled by a metallic coating formed on the surface thereof. 6. The method for forming a metallic film on a non-conductive material according to any one of 5 to 5. (10) A method for forming a metallic coating on a non-conductive object, which further comprises electrolytically plating the surface of the platinum metallic coating obtained by the method of claim 1. (11) When applying the electrolytic tin plating according to claim 10, the electrolytic tin plating is performed by rubbing the surface of the metal coating of white metal.
The method for forming a metallic coating on a non-conductive object according to claim 10.