JP2001059180A - Electroless plating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of forming an electroless plating film free from defects such as pits and flowing plating unevenness (an aggregate of micro-projections), good in appearance and moerover excellent in adhesion on a glass product by using a stable treating soln. usable over a long period. SOLUTION: A glass product as the object to be plated is brought into contact with an aq. soln. contg. at least one kind of surface conditioner component selected from a cationic surfactant, an amphoteric surfactant and a silane coupling agent having amino groups on the terminals, is thereafter brought into contact with an aq. soln. contg. anionic complex ions of catalytic metal, is then brought into contact with an aq. soln. contg. a reducing agent and is subsequently subjected to electroless plating treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for electroless plating glass products.

[0002]

2. Description of the Related Art In recent years, fixed magnetic disk devices have been widely used as external recording devices such as computers. Conventionally, a non-magnetic aluminum substrate has been widely used as a substrate of a magnetic disk mounted on the fixed magnetic disk, and electroless Ni-P plating is often used as a base non-magnetic plating of the aluminum substrate. Has been

However, in recent years, it has been desired to increase the recording density, reduce the thickness, and reduce the size of the magnetic disk, and accordingly, as the material of the magnetic disk, glass that can be easily reduced in size and thickness and has high smoothness is obtained. Substrates have been used.

When forming an electroless Ni-P plating film as a nonmagnetic plating film on such a glass substrate, it is technically necessary to form a plating film having sufficient adhesion and smoothness. It is difficult, and various pretreatment methods for improving adhesion, pretreatment methods for improving smoothness, and the like have been proposed.

For example, two-stage etching of a chromic acid-sulfuric acid mixed solution and a nitric acid solution is performed, followed by etching with an alkaline solution, sensitization treatment with a stannous chloride / hydrochloric acid aqueous solution, and furthermore, silver salt and palladium salt. There has been proposed a method of performing electroless Ni plating after performing an activation treatment with a solution (Japanese Patent Application Laid-Open No. 53-19932), but the processing step is complicated, and a sensitizing solution or an activation treatment is performed. There is a problem that the bath life of the liquid is short.

Further, after cleaning with a mixed solution of sulfuric acid and potassium bichromate, sensitizing treatment with an aqueous solution of stannous chloride / hydrochloric acid, activation treatment with a solution of palladium chloride / hydrochloric acid, and electroless Ni— Method of performing P plating (Japanese Patent Laid-Open No. 48-8 / 48)
No. 5614), alkali degreasing treatment, etching treatment with an aqueous solution containing hydrofluoric acid and potassium fluoride, surface foreign matter removal treatment with a hydrochloric acid aqueous solution, surface adjustment with an aqueous solution containing sodium methoxide, and a stannous chloride / hydrochloric acid aqueous solution There is a method of sequentially performing a sensitization treatment and an activation treatment with a palladium chloride / hydrochloric acid solution, followed by electroless Ni-P plating (Japanese Patent Application Laid-Open No. 7-334841). This is a method in which sensitization is performed using a solution containing stannous tin, and stannous chloride contained in the processing solution is easily oxidized to tetravalent tin, resulting in turbidity of the bath and short bath life. There is. Also,
Since the flow-like appearance unevenness (aggregate of fine projections) is likely to occur at the beginning of plating due to the influence of tin salt, the electroless Ni-
Thicken the P plating or dry once after the activation process,
Thereafter, it is attempted to prevent the occurrence of unevenness by performing electroless Ni-P plating. However, the process is complicated, and in the method of drying after the activation process, pits or non-plating There is a problem that plating defects such as portions and plating unevenness are likely to occur.

[0007]

SUMMARY OF THE INVENTION The main object of the present invention is to:
Pit and flow-like plating unevenness (aggregate microprojections) on glassware using a stable and long-term treatment liquid
It is an object of the present invention to provide a method capable of forming an electroless plating film having no defects, good appearance, and excellent adhesion.

[0008]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventor has found that a surface of a glass product is treated with a cationic surfactant, an amphoteric surfactant and an amino group at a terminal. After being treated with an aqueous solution containing at least one surface conditioner component selected from silane coupling agents having, the glass product treated with the surface conditioner is brought into contact with an aqueous solution containing an anionic complex ion of a catalytic metal. By applying a catalyst for electroless plating to the surface of a glass product by attaching a catalytic substance to the surface and then reducing and metallizing the catalytic substance, an electroless plating film having good appearance and adhesion is obtained. It is possible to form
In addition, they found that the processing solution used had good stability and could be used for a long period of time, and thus completed the present invention.

That is, the present invention provides the following electroless plating method and a glass product having an electroless plating film formed thereon. 1. The glass product to be plated was brought into contact with an aqueous solution containing at least one type of surface conditioner component selected from a cationic surfactant, an amphoteric surfactant, and a silane coupling agent having a terminal amino group. A method for electrolessly plating a glass product, comprising: contacting an aqueous solution containing an anionic complex ion of a catalytic metal, and then contacting with an aqueous solution containing a reducing agent, and then performing an electroless plating treatment. 2. Item 2. The method according to item 1, wherein the surface conditioner component is at least one selected from an alkyl quaternary ammonium salt type surfactant and 3-aminopropyltriethoxysilane. 3. Item 3. The method according to Item 1 or 2, wherein the aqueous solution containing the anionic complex ion of the catalytic metal is an aqueous solution containing palladium chloride and hydrochloric acid and having a pH of 2 to 6. 4. Item 4. The method according to Item 3, wherein the aqueous solution containing an anionic complex ion of the catalyst metal further contains an alkali halide. 5. Items 1-4 wherein the reducing agent is an alkylamine borane
The method according to any of the above. 6. The glass product is a glass substrate for a magnetic disk, and the formed electroless plating film has a P content of 10 to 14% by weight.
6. The method according to any one of the above items 1 to 5, which is a Ni-P film. 7. A glass product having an electroless plating film formed by the method according to any one of the above items 1 to 6.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the electroless plating method of the present invention,
Various glass products can be used as the object to be plated, and the material and shape thereof are not particularly limited. For example, various shapes of glass products made of crystallized glass, soda lime glass, or the like can be used as the object to be plated. In particular,
The method of the present invention is a method that can easily form an electroless plating film having good adhesion and smoothness on a glass product, and is required to form a good nonmagnetic film having excellent smoothness. This method is suitable as an electroless plating method for a glass substrate for a disk.

The glass product to be plated is usually subjected to a degreasing treatment before being subjected to the following treatment steps of the present invention. The degreasing treatment may be performed by a known method according to the material of the glass product, and usually, the degreasing treatment may be performed using a commercially available degreasing agent, but when using a degreaser containing silicate, It is preferable to use a phosphate-containing weak alkaline degreasing agent, since a silicate film may be formed on the surface of the glass product to inhibit the formation of a good plating film.

After performing the degreasing treatment, the surface of the glass product is subjected to an etching treatment, if necessary, before being subjected to the treatment step of the present invention. There is also no particular limitation on the method of the etching treatment, and the treatment may be performed according to a conventional method according to the material of the glass product to be used. For example, as an example of an etching method when crystallized glass used as a glass substrate for a magnetic disk is to be plated, 5 to 40 ml / l of 50% by weight hydrofluoric acid and 10% of ammonium fluoride are used.
An etching solution consisting of an aqueous solution containing ４５45 g / l may be used, and the object to be plated may be immersed in the etching solution at a solution temperature of about 15 to 30 ° C. for about 2 to 10 minutes.

According to such an etching treatment, the surface of the glass product can be completely degreased.
The adhesion between the glass product and the plating film can be improved.

Hereinafter, each processing step of the present invention will be described. Each process may be performed in the following order.
A water washing process is performed between each step. (1) Treatment with an aqueous solution of a surface conditioner: In the electroless plating method of the present invention, after performing a pretreatment such as a degreasing treatment and an etching treatment, a cationic surfactant, an amphoteric surfactant, and an amino group at a terminal are added. A glass product as an object to be plated is brought into contact with an aqueous solution containing at least one surface conditioner component selected from silane coupling agents. This treatment allows the surface conditioner component to adhere to the surface of the glass product.

As the cationic surfactant and the amphoteric surfactant, an alkyl quaternary ammonium salt type surfactant is particularly preferred. Specific examples thereof include coconut oil alkyldimethylbenzylammonium chloride and coconut oil alkyltrimethylammonium. Chloride, coconut oil alkyltrimethylammonium bromide, tallow alkyltrimethylammonium chloride, cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, alkylaminopropyldiammonium, tetradecyldimethylbenzylammonium chloride, hexadecyltrimethylammonium chloride, octadecyldimethylbenzylammonium chloride, Octadecyltrimethylammonium chloride, docosenyltrimethyl Ammonium chloride, stearyl trimethyl ammonium chloride, coconut oil alkyl dimethyl betaines, alkyl dimethyl betaines,
Alkyl sulfobetaine and the like can be mentioned, in particular,
Palm oil alkyldimethylbenzylammonium chloride, coconut oil alkyltrimethylammonium chloride, coconut oil alkyltrimethylammonium bromide and the like are preferred.

Examples of the silane coupling agent having an amino group at the terminal include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-
(2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N, N-bis [3- (trimethoxysilyl) propyl] ethylenediamine, p −
[N- (2-aminoethyl) aminomethyl] phenethyltrimethoxysilane and the like can be exemplified. In particular, 3-aminopropyltriethoxysilane is preferable because hydrolysis hardly occurs.

A cationic surfactant, an amphoteric surfactant,
The surface conditioner component comprising a silane coupling agent having an amino group at the terminal can be used alone or in combination of two or more.

The preferred content of the surface conditioner component varies depending on the type of the surface conditioner component. When a surfactant is used as the surface conditioner component, the content is preferably about 0.1 to 3 g / l. More preferably, it is about 0.5 to 1.5 g / l. When two or more surfactants are used in combination, the total amount may be within the above range. When a silane coupling agent having an amino group at a terminal is used as a surface conditioner component, the silane coupling agent has a content of 0.1 to 10 g /
The content is preferably about 1 and more preferably about 1 to 8 g / l.

When a surfactant and a silane coupling agent are used in combination as the surface conditioner components, the amount of each component can be within the above range, and the upper limit of the total amount of both components is as follows: A range of about 13 g / l, which is the sum of the upper limits of the respective compounding amounts, can be used. Regarding the lower limit, since each component can exert the same effect,
The total amount may be about 0.1 g / l or more. When a surfactant and a silane coupling agent are used in combination, the amount of the silane coupling agent used can be reduced as compared with the case where the silane coupling agent is used alone, and the silane coupling agent is hydrolyzed. This is advantageous in that the amount of the product can be suppressed.

When the concentration of the surface conditioner component is insufficient, when the catalyst is treated with an aqueous solution containing a catalytic metal as described below, the adsorption of the catalytic metal becomes non-uniform, which may cause uneven plating and non-precipitation of the plating. On the other hand, if the concentration of the surface conditioner component is too high, the catalytic metal is excessively adsorbed and plating defects such as pits and nodules are likely to occur, and the adhesion of the plating may be reduced, which is not preferable.

As a method of bringing a glass product to be plated into contact with an aqueous solution containing a surface conditioner component, the glass product is usually immersed in an aqueous solution containing a surface conditioner component. The liquid temperature during the treatment is preferably about 15 to 60 ° C, more preferably about 25 to 50 ° C. The processing time cannot be determined unequivocally because it varies depending on the concentration and temperature of the processing solution.
The range may be about 20 minutes, preferably about 3 to 10 minutes. If the temperature of the treatment liquid is too low or the treatment time is too short, when treating with an aqueous solution containing a catalyst metal, the adsorption of the catalyst metal tends to be uneven, which may cause plating unevenness and non-precipitation of plating. . On the other hand, if the solution temperature during treatment is too high, the surface conditioner component is decomposed and roughness or pits are easily generated in the plating film, and if the treatment time is too long, when treating with an aqueous solution containing a catalyst metal, Excessive adsorption of the catalytic metal may easily cause plating defects such as pits and nodules, and may further deteriorate the adhesion of the plating. (2) Treatment with an aqueous solution containing a catalyst substance : In the above step (1), after the surface conditioner component is attached to the surface of the glass product, it is brought into contact with an aqueous solution containing the catalyst substance to give a glass product to be plated. Apply catalytic material.

In this treatment step, an aqueous solution containing an anionic complex ion of a catalytic metal is used as an aqueous solution containing a catalytic substance. When the catalyst metal is present as an anionic complex ion, when a surfactant is used in the above-mentioned step (1), a portion of the cationic group of the surfactant adhering to the surface of the object to be plated is applied. The catalyst metal can be efficiently attached, and when a silane coupling agent is used, the -OR group forms an oxane bond (GO-Si) with the glass surface, while the terminal amino group is Ammonium cations are formed in the acidic catalyst aqueous solution, and the catalyst metal can be efficiently attached to this portion.

As the catalytic metal, various noble metals known to have catalytic activity for electroless plating can be used. As such a noble metal, P
d, Au, Pt, Rh and the like can be exemplified. Of these,
In particular, Pd is preferable from the viewpoints of stability and cost of the catalyst metal-containing aqueous solution. An aqueous solution containing an anionic complex ion of these catalyst metals is an aqueous solution of a catalyst metal in which a halogen anion, a CN anion, or the like is coordinated to form an anion complex. In the present invention, particularly, a halogeno anion is used. An aqueous solution containing the complex is preferred. For example, an example of the anionic complex ion of palladium includes [PdCl ₄ ] ²⁻ which is a chloro complex.

As an example of an aqueous solution containing Pd as a catalytic metal, 0.1 to 0.6 g / l of palladium chloride is used.
Degree, preferably about 0.15 to 0.3 g / l, 35
% Hydrochloric acid in an amount of about 0.3 to 3 g / l and a pH of about 2 to 6, preferably about 3 to 5. In this aqueous solution, if the concentration of palladium chloride is too low, the electroless plating film is likely to be non-precipitated due to insufficient adsorption of the catalyst, while if the concentration of palladium chloride is too high, the adsorption amount of the catalyst becomes excessive, This is not preferred because nodules may be generated or the adhesion may decrease. Further, if the pH is too low, the amount of the catalyst adsorbed is insufficient, so that non-precipitation of the electroless plating film and uneven appearance are likely to occur, and if the pH is too high, the bath becomes unstable and may be decomposed. It is not preferable.

If necessary, an alkali halide may be added to the aqueous solution containing palladium chloride as a stabilizer, whereby the bath life can be extended. As the alkali halide, sodium bromide, potassium bromide, sodium iodide, potassium iodide, sodium chloride, potassium chloride and the like can be used. The compounding amount of the alkali halide is 0.3
４4 g / l, preferably 0.5 to 2 g / l
More preferably, it is about l. When the compounding amount of the alkali halide is in this range, the bath stability can be further improved. However, when the compounding amount is too large, the amount of adsorbed catalyst decreases, which is not preferable. In addition, this aqueous solution contains
A pH buffer can be added if necessary. As the pH buffering agent, borax, sodium phosphate, potassium phosphate, sodium carbonate, potassium carbonate and the like can be used, and borax is particularly preferable. The amount of the pH buffer is
It is preferably about 0.2 to 3 g / l, more preferably about 0.5 to 2 g / l.

As a method for bringing the aqueous solution containing palladium chloride into contact with the object to be plated, the object to be plated may be usually immersed in this aqueous solution. The temperature of the processing solution at this time is preferably about 15 to 50 ° C.
More preferably, the temperature is set to about 40 ° C. Processing time is
Since it differs depending on the palladium chloride concentration and the liquid temperature, it cannot be unconditionally determined, but is usually preferably about 2 to 15 minutes, more preferably about 3 to 8 minutes.

If the temperature of the processing solution is too low or the processing time is too short, the amount of the catalyst substance adsorbed may be insufficient, resulting in non-precipitation of the plating. If the time is too long, the catalytic substance may be excessively adsorbed to cause plating defects such as nodules or the adhesion may be easily reduced, and further, the stability of the liquid containing the catalytic substance may be reduced to cause bath decomposition. Is not preferred. (3) Reduction treatment: In this step, the object to be plated on which the catalyst substance has been attached in the above step (2) is brought into contact with an aqueous solution containing a reducing agent to reduce the attached catalyst substance and reduce the metal content. Become

Examples of the reducing agent include alkali metal borohydride compounds such as sodium borohydride and potassium borohydride, and dimethylamine borane (DMA).
B), alkylamine borane such as diethylamine borane, trimethylamine borane, triethylamine borane, hydrazine and the like can be used, and alkylamine borane is particularly preferable. These reducing agents can be used alone or in combination of two or more.

When an aqueous solution containing these reducing agents is used, the stannous chloride contained in the processing solution tends to be tetravalent, which is liable to occur in the conventional method of sensitizing with a solution containing stannous chloride. Can be prevented from becoming turbid or shortening the life of the liquid. Further, it is advantageous in that there is no occurrence of a flow-like appearance unevenness (aggregate of fine projections) which occurs at an early stage of plating due to a tin salt, which is a fatal drawback for glass products used for electronic materials.

The concentration of the reducing agent is preferably about 0.1 to 3 g / l, more preferably about 0.2 to 1 g / l. If the concentration of the reducing agent is too low, the catalytic substance becomes insufficiently reduced, and plating unevenness or non-precipitation of the plating may occur.On the other hand, even if the concentration exceeds the above range, the effect does not change so much and economically. It is useless.

As a treatment method using an aqueous solution containing a reducing agent, the object to be plated treated in the above step (2) may be usually immersed in this aqueous solution. The liquid temperature at that time is preferably about 15 to 60 ° C, and 30 to 50 ° C.
It is more preferable to set the degree. Although the treatment time varies depending on the concentration of the reducing agent and the treatment temperature, it is usually preferably about 1 to 10 minutes, more preferably about 3 to 8 minutes.

If the temperature of the treatment liquid is too low or the treatment time is too short, the catalyst metal may be insufficiently reduced, resulting in uneven plating or non-precipitation of the plating. On the other hand, if the liquid temperature during the treatment is too high or the treatment time is too long, the effect does not change, but in particular, if the treatment temperature is high, self-decomposition of the reducing agent is promoted, which is uneconomical. . (4) Electroless plating treatment : In this step, after the catalyst substance is metallized in the above step (3), the object to be plated is subjected to electroless plating treatment.

The electroless plating solution is not particularly limited.
Any known self-catalytic electroless plating solution can be used. As such an electroless plating solution,
For example, electroless Ni-P plating solution, electroless Ni-B plating solution, electroless Ni-P-B plating solution, electroless Ni-P-
Co plating solution, electroless Ni-PW plating solution, electroless N
i-B-W plating solution, electroless Ni-P-Fe plating solution,
An electroless Ni-Cu-P plating solution, an electroless copper plating solution and the like can be exemplified.

The conditions for the electroless plating are not particularly limited, and the plating may be performed according to a conventional method according to the type of the electroless plating solution to be used.

For example, when a nonmagnetic plating film is formed on a glass substrate for a magnetic disk by the plating method of the present invention, electroless Ni having a phosphorus content of about 10 to 14% by weight is used.
It is preferable to form a -P plating film. In order to form such an electroless Ni—P plating film, a known electroless N film capable of forming a plating film having a phosphorus content in this range is used.
Plating may be performed using an i-P plating solution according to known conditions. As an example of such a plating method, an electroless plating treatment may be performed at a pH of about 4 to 5 and a solution temperature of about 70 to 93 ° C. using an electroless Ni—P plating solution having the following composition.

Nickel sulfate 4-7 g / l (as nickel metal) Sodium hypophosphite 20-40 g / l Malic acid 10-30 g / l Succinic acid 5-15 g / l Lead 0.1-1 mg / l Plating may be performed until a plating film having an appropriate thickness according to the intended use is formed. For example, when a non-magnetic electroless Ni-P plating film is formed on a glass substrate for a magnetic disk, 3 It is appropriate to form a plating film of about 15 μm.

[0037]

According to the electroless plating method of the present invention, a glass product is used as an object to be plated, has good adhesion, and has no defects such as pits and flow-like plating unevenness (aggregates of minute projections). An electroless plating film having a good appearance can be formed.
In addition, each processing solution used has good stability and can be used for a long time.

The method of the present invention is a method by which a good nonmagnetic film having excellent smoothness can be easily formed, and is particularly useful as an electroless plating method for a glass substrate for a magnetic disk.

[0039]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. Example 1 The following treatment was performed using a crystallized glass substrate having a diameter of 3.5 inches as an object to be plated.

Phosphate-type weak alkaline degreasing agent (trade name: Descreen 20 (trade name) manufactured by Okuno Pharmaceutical Co., Ltd.)
(0 ml / l aqueous solution), the object to be plated was immersed at a liquid temperature of 50 ° C for 5 minutes to perform a degreasing treatment. After that, it was washed with water and placed in an aqueous solution containing 20 ml / l of 50% hydrofluoric acid and 30 g / l of ammonium fluoride at 25 ° C.
Dipping the object to be plated for 5 minutes to perform an etching process,
Washed with water. Thereafter, immersion treatment was performed under the conditions shown in Table 1 below using the respective aqueous solutions containing the surface conditioner components shown in Table 1 below.

Then, after washing with water, 0.15 palladium chloride was added.
g / l, 35% hydrochloric acid 0.55 g / l, and sodium chloride 1 g / l, and the object to be plated was immersed in an aqueous solution adjusted to pH 4 with sodium hydroxide to provide a catalyst.
It was washed with water, immersed in an aqueous solution containing 0.3 g / l of dimethylamine borane at 40 ° C. for 5 minutes to perform a reduction treatment, and washed with water.

Then, using an electroless Ni-P plating solution (Top Nicolon NAC, manufactured by Okuno Pharmaceutical Co., Ltd.)
H4.2, at a bath temperature of 80 ° C, immersion of the object to be plated to a thickness of 8
A μm electroless Ni-P plating film was formed.

The number of pits, the presence or absence of flow unevenness, and the adhesiveness of the formed plating film were evaluated by the following methods. The results are shown in Table 1 below. * The number of pits: Using an optical microscope, observe 10 places on each side of the substrate at a magnification of 100 times, a total of 20 places,
The number of pits was measured. * The presence or absence of flow-like unevenness: The presence or absence of flow-like unevenness was visually determined. * Adhesion: Heat treatment is performed in an electric oven at 250 ° C for 1 hour. Based on the tape test method of JIS H-85015.1, 5 scratches reaching the substrate at 2mm intervals are attached vertically and horizontally, 25 in total. After the cell was made and the adhesive tape was stuck, the cell was rapidly peeled off, and the number of cells not peeled was measured.

[0044]

[Table 1]

As is evident from the above results, Test No. 1 using coconut oil alkyldimethylbenzylammonium chloride as a surface conditioner component. Test Nos. 1 to 7 using coconut oil alkyltrimethylammonium bromide. Test No. 8-14 using 3-aminopropyltriethoxysilane. 15 to 18, and tests 19 to 22 using a combination of 3-aminopropyltriethoxysilane and coconut oil alkyldimethylbenzylammonium chloride
In each case, an electroless Ni-P plating film having good adhesion and no pits or uneven flow was formed. Example 2 The same object to be plated as in Example 1 was subjected to degreasing and etching in the same manner as in Example 1. After treating with an aqueous solution containing a surface conditioner in the same manner as in 1, the pH was adjusted using sodium hydroxide.
It was immersed in a catalyst substance-containing aqueous solution having the following composition adjusted to a range of 2 to 6 at room temperature for 5 minutes. * Aqueous solution containing catalyst substance palladium chloride 0.15 g / l 35% hydrochloric acid 0.55 g / l sodium chloride 1.0 g / l borax 1.0 g / l pH 2-6 (adjusted with sodium hydroxide) Reduction treatment and electroless Ni were performed in the same manner as in Example 1.
-P plating was performed to form an electroless Ni-P plating film having a thickness of 8 µm.

Example 1 of the formed plating film
In the same manner as in the above, the number of pits, the presence or absence of flow-like unevenness, and the adhesion were evaluated. Further, palladium on the glass substrate which had been subjected to the reduction treatment was dissolved in aqua regia, and the amount of palladium adsorbed was measured by an ICP plasma emission spectrometer.

The results are shown in Table 2 below.

[0048]

[Table 2]

As is evident from the results in Table 2, the use of each of the above-mentioned aqueous solutions containing the catalyst substance enables the formation of an electroless Ni-P plating film having good adhesion and no pits or uneven flow. PH of the aqueous solution containing the catalyst substance is 2 to 6
In the range, the adsorption amount of palladium increased as the pH increased. In addition, each of the above-mentioned aqueous solutions containing a catalyst substance had good bath stability even after standing for one week. Example 3 Test No. 1 of Example 1 18 in the same manner as in Example 2, except that the treatment was carried out with an aqueous solution containing a silane coupling agent as a surface conditioner component.
A P plating film was formed.

In the same manner as in Example 2, the number of pits, the presence or absence of flow unevenness, the adhesion, and the amount of palladium adsorbed were measured. The results are shown in Table 3 below.

[0051]

[Table 3]

As is evident from the results in Table 3, when the silane coupling agent was used as the surface conditioner component,
By using an aqueous solution containing a catalyst substance having a pH of 3 or 5, an electroless Ni-P plating film having good adhesion and having no pits or uneven flow could be formed. Further, when the pH of the aqueous solution containing the catalyst substance was high, the amount of adsorbed palladium was increased, and at the same pH, the amount of adsorbed palladium was larger than in Example 2. Example 4 A catalyst substance-containing aqueous solution having the same composition as the catalyst substance-containing aqueous solution used in Example 2 was used except that sodium bromide was used instead of sodium chloride, and the other conditions were the same as in Example 2. To form an electroless Ni-P plating film.

In the same manner as in Example 2, the number of pits, the presence or absence of flow unevenness, the adhesion, and the amount of palladium adsorbed were measured. The results are shown in Table 4 below.

[0054]

[Table 4]

As is clear from the above results, even when the aqueous solutions containing the respective catalyst substances shown in Table 4 were used, the adsorption amount of palladium was almost the same as in Example 2, and the plating films formed were all The adhesiveness was good, and there were no pits or flow-like unevenness. In addition, each of the above-mentioned aqueous solutions containing a catalyst substance had good bath stability even after standing for one week. Example 5 Test No. 1 of Example 1 18 in the same manner as in Example 4, except that the treatment was performed with an aqueous solution containing a silane coupling agent as a surface conditioner component.
A P plating film was formed.

In the same manner as in Example 4, the number of pits, the presence or absence of flow-like unevenness, the adhesion, and the amount of palladium adsorbed were measured. The results are shown in Table 5 below.

[0057]

[Table 5]

As is clear from the above results, when a silane coupling agent was used as a surface conditioner component,
By using the catalyst substance-containing aqueous solution shown in Table 5, the electroless Ni- is excellent in adhesion and free from pits and uneven flow.
A P plating film could be formed. Example 6 The same object to be plated as in Example 1 was subjected to degreasing and etching in the same manner as in Example 1. After treatment with an aqueous solution containing a surface treating agent in the same manner as in Example 1, treatment with an aqueous solution containing a catalyst substance was carried out in the same manner as in Example 1.

Thereafter, reduction treatment was carried out by changing the dimethylamine borane concentration and the treatment conditions in the aqueous solution containing dimethylamine borane as a reducing agent as shown in Table 6 below. P plating was performed to form an electroless Ni—P plating film having a thickness of 8 μm.

Example 1 of the formed plating film
In the same manner as in the above, the number of pits, the presence or absence of flow-like unevenness, and the adhesion were evaluated. The results are shown in Table 6 below.

[0061]

[Table 6]

As can be seen from the above results, in any case, the electroless N has good adhesion and no pits or uneven flow.
An i-P plating film was formed. Comparative Example 1 The same plating object as in Example 1 was subjected to degreasing and etching in the same manner as in Example 1, and then an aqueous solution containing stannous chloride 7 g / l and 35% hydrochloric acid 11 g / l. After sensitization by immersion in water at 25 ° C for 3 minutes, washing with water, 0.15 g / l of palladium chloride and 0.5 g of 35% hydrochloric acid were performed.
A catalyst for electroless plating was provided by immersing in an aqueous solution containing 1 / l at 25 ° C. for 3 minutes for activation. Thereafter, an electroless Ni-P plating film was formed in the same manner as in Example 1, and the obtained plating film was evaluated.

As a result, the adhesion of the formed plating film was good and no pits were generated, but flow-like unevenness of appearance occurred on both surfaces of the substrate. Observation of this external appearance unevenness with an optical microscope at a magnification of 100 times revealed an aggregate of minute projections.

When the sensitizing solution containing stannous chloride and hydrochloric acid was left indoors for one week, the divalent tin
It was oxidized to a valence to produce white turbidity, and the bath stability was poor. Comparative Example 2 After performing activation treatment with an aqueous solution containing palladium chloride and hydrochloric acid in the same manner as in Comparative Example 1, it was dried in an electric oven at 80 ° C. for 20 minutes in air. Thereafter, an electroless Ni-P plating film was formed in the same manner as in Example 1, and the obtained plating film was evaluated.

As a result, the adhesion of the formed plating film was good, and there was no flow-like unevenness in the appearance. Plating parts occurred.

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Claims (7)

[Claims] 1. A glass product to be plated contains at least one surface conditioner component selected from a cationic surfactant, an amphoteric surfactant, and a silane coupling agent having an amino group at a terminal. After contact with aqueous solution,
An electroless plating method for a glass product, comprising: contacting an aqueous solution containing an anionic complex ion of a catalytic metal, then contacting with an aqueous solution containing a reducing agent, and then performing an electroless plating treatment. 2. The surface conditioner component is at least one selected from alkyl quaternary ammonium salt type surfactants and 3-aminopropyltriethoxysilane.
The method described in. 3. An aqueous solution containing an anionic complex ion of a catalytic metal, wherein the aqueous solution contains palladium chloride and hydrochloric acid at pH 2 to 3.
The method according to claim 1 or 2, wherein the aqueous solution of (6) is used. 4. The method according to claim 3, wherein the aqueous solution containing an anionic complex ion of the catalyst metal further contains an alkali halide. 5. The method according to claim 1, wherein the reducing agent is an alkylamine borane. 6. The glass product is a glass substrate for a magnetic disk, and the formed electroless plating film has a P content of 10-1.
The method according to any one of claims 1 to 5, wherein the coating is a 4 wt% Ni-P coating. 7. A glass product having an electroless plating film formed by the method according to claim 1.