JP3151533B2 - Composite plating solution, composite plating method and composite plating film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composite plating solution, a composite plating method, and a composite plating film.

[0002]

2. Description of the Related Art Fluorinated graphite and polytetrafluoroethylene (PTFE) have characteristics such as self-lubrication, low friction, water repellency, oil repellency, and non-adhesiveness. Dispersed in an aqueous salt solution, electroplated fluorinated graphite, etc. with metal on the substrate by plating to combine the unique properties of non-metallic fluorinated graphite etc. with the properties of the matrix metal Methods for forming composite coatings are known.

In such a plating method, in order to disperse and deposit graphite fluoride in an aqueous solution of a metal salt, it is necessary to positively charge graphite fluoride particles and to create a completely wet state. . However, fluorinated graphite has extremely strong water repellency, and it is necessary to add a large amount of a surfactant in order to obtain a stable dispersion state. Also,
The fluorinated graphite in the fluorinated graphite eutectoid plating film thus obtained has a very poor water repellency immediately after plating because its surface is covered by a surfactant. It is necessary to dry the plating surface.

[0004]

Means for Solving the Problems In view of the above problems, the present inventor has conducted intensive studies. As a result, when pitch fluoride is used instead of graphite fluoride as a substance to be dispersed,
With a very small amount of surfactant used, it can be stably dispersed in the plating solution, and the resulting composite plating film has excellent water repellency compared to a plating film made of eutectoid graphite or PTFE. Further, it has been found that even after plating, high water repellency is exhibited without heating and drying.

That is, the present invention provides the following composite plating solution, composite plating method and composite plating film. i) A composite plating solution characterized by dispersing pitch fluoride in an electroplating solution using a cationic surfactant in the plating solution. ii) A composite in which pitch fluoride is eutectoidally deposited on a base material by an electroplating method using a plating solution in which pitch fluoride is dispersed in an electroplating solution using a surfactant showing cationicity in the plating solution. A composite plating method characterized by forming a plating film. iii) A composite plating film obtained by eutecting pitch fluoride into a metal plating film.

The pitch fluoride used in the present invention has a composition formula C
A compound having a composition represented by Fx (0.5 <x <1.8), in which one to three fluorine atoms are firmly bonded to each carbon atom by a covalent bond. The color is brown to yellowish white to white, is a compound which is very stable in air and has excellent water resistance and chemical resistance, and has a layered structure. Industrially, it is obtained by directly reacting the pitch with fluorine gas at around normal temperature.

In the present invention, the particle size of the pitch fluoride to be added is not particularly limited. It is desirable to use pitch,
Usually, it is preferably about 10 μm or less, more preferably 1 μm or less. The amount of the fluorinated pitch added to the plating solution is not particularly limited.
It may be determined according to the desired amount of eutectoid, etc., usually 500 g /
It may be about 1 or less, preferably about 1 to 50 g / 1.

In the present invention, the type of plating solution to which pitch fluoride is to be added is not particularly limited, and may be any ordinary electroplating solution capable of depositing a metal on a cathode by electroplating. For example, copper, nickel, chromium, zinc, cadmium, tin, iron, lead and their alloy plating solutions can be mentioned. These plating solutions are known in various compositions, and any of these known plating solutions can be used in the present invention.

In the plating solution of the present invention, a surfactant is used to uniformly disperse the pitch fluoride in the plating solution. As the surfactant, it is necessary to use a surfactant molecule exhibiting cationicity at the pH of the plating solution. For example, a water-soluble cationic type, a nonionic type, or a surfactant exhibiting cationicity at the pH of the plating solution is required. Any amphoteric surfactant can be used. In this case, as the cationic surfactant, a quaternary ammonium salt, a secondary or tertiary amine,
Imidazolines and the like; non-ionic surfactants include polyoxyethylene-based, polyethyleneimine-based and ester-based surfactants; and amphoteric surfactants include carboxylic acid-based and sulfone-based surfactants. Can be In particular, it is preferable to use a fluorinated surfactant having a CF bond in the molecule. A nonionic surfactant having a CF bond in a molecule shows cationicity only in the case of an acidic plating solution.

The amount of the surfactant added to the plating solution is preferably about 1 mg to 100 mg per 1 g of pitch fluoride, more preferably about 1 mg to 30 mg per 1 g of pitch fluoride. In the present invention, by using pitch fluoride as the substance to be dispersed, it is possible to uniformly disperse the surfactant in the plating solution even when the amount of the surfactant used is extremely small. As a result, the amount of the surfactant attached to the fluorinated pitch decreases, and high water repellency can be exhibited even immediately after plating.

In the plating solution of the present invention, it is preferable to perform plating while stirring the plating solution in order to uniformly disperse the fluoride pitch. The stirring method is not particularly limited, and ordinary mechanical stirring means, for example, a method of screw stirring, a method of stirring with a magnetic stirrer, and the like can be adopted.

The plating conditions may be appropriately determined according to the type of plating solution to be used, and generally, the same solution temperature, pH, and current density as those in normal plating may be used.

In the plating film formed by the plating solution of the present invention, the amount of pitch fluoride contained in the plating film may be appropriately determined according to the purpose of use. The amount of eutectoid pitch fluoride can be appropriately changed by adjustment, adjustment of plating conditions, and the like. Generally, the greater the amount of pitch fluoride contained in the plating film, the lower the adhesion between the plating metal and the base material. Therefore, the amount of pitch fluoride in the plating film is 80% by volume.
It is appropriate that the amount is not more than the extent, and especially when the mechanical strength of the plating film is required, it is necessary to avoid co-depositing a large amount of pitch fluoride, and the volume of It is preferable that the rate be about 5% or less.
Further, the lower limit of the amount of eutectoid pitch fluoride is not particularly limited,
The volume fraction may be appropriately set according to the purpose of use, but is usually preferably about 1% or more in volume fraction in order to produce the effect of eutectoid pitch fluoride.

[0014]

According to the composite plating solution of the present invention, it is possible to form a plating film having higher water repellency than a conventional plating film obtained by co-depositing fluorinated graphite, PTFE or the like. Further, since the dispersibility of the fluorinated pitch in the plating solution is very good, the amount of the surfactant added can be significantly reduced, and good water repellency is exhibited immediately after plating.

[0015]

The present invention will be described in more detail with reference to the following examples.

[0016]

Example 1 Softening point: 100 ° C., quinoline insoluble content: 0.2 w
A double amount of hydrogenated anthracene oil was added to a coal tar pitch containing 30% by weight of benzene insoluble matter and 30% by weight of benzene.
The mixture was heated for 0 minutes, and the reduced pitch was obtained by removing the hydrogenated anthracene oil at 300 ° C. under reduced pressure.

Next, a low-molecular-weight component is removed from the reduced pitch by introducing nitrogen gas, and thermally polymerized at 400 ° C. for 5 hours to obtain a softening point of 300 ° C., a quinoline insoluble content of 60 wt%,
Benzene insoluble content 98 wt%, mesophase content 90%
The above mesophase pitch was obtained.

After 50 g of the obtained pitch was charged into a nickel reaction vessel, the system was evacuated and filled with argon gas. Then, at 70 ° C., a fluorine gas (mixed gas of 20 vol% fluorine and 80 vol% argon) was supplied at an average flow rate of 6%.
After flowing at a flow rate of 50 cc / min and reacting for 20 hours, 144 g of pitch fluoride was obtained. As a result of an elemental analysis, the composition formula was CF _1.39 .

1% by weight of the pitch fluoride thus obtained was added to a nickel electrolytic bath having the following composition. At that time, a tertiary perfluoroammonium salt (C ₈ F ₁₇ SO ₂ NH (CH ₂ ) ₃ N ⁺ (C
_3. H ₃ ) ₃ .Cl ⁻ ) per 1 g of pitch fluoride;
5 mg was added.

[0020] Using a nickel plate and a copper plate as a positive electrode and a negative electrode, respectively, a liquid temperature of 45 ° C. ± 5 ° C., a pH of 4.2, and a current density of 1-5 A / dm ²
Under the conditions described above, plating was performed with an electric quantity of 1000 coulombs while stirring with a screw. The contact angle of water was measured on the obtained plating film immediately after plating and after vacuum drying, and the water repellency was examined. The results are shown in Table 1.

[0021]

Comparative Example 1 Nickel plating was performed in the same manner as in Example 1 except that pitch fluoride was not added. The results of measuring the contact angle of water on the obtained nickel plating film are shown in Table 1 below.

[0022]

Comparative Example 2 1% by weight of fluorinated graphite was added to a nickel electrolytic bath having the following composition. At this time, a tertiary perfluoroammonium salt (C ₈ F ₁₇ SO
₂ NH (CH ₂ ) ₃ N ⁺ (CH ₃ ) ₃ .Cl ⁻ ) was added to 40 mg per 1 g of fluorinated graphite.

[0023] Using the plating bath obtained, plating was performed under the same conditions as in Example 1, and the water repellency of the plating film was measured. The results are shown in Table 1 below.

[0024]

Comparative Example 3 Plating was performed in the same manner as in Comparative Example 2 except that PTFE was used instead of fluorinated graphite, and the amount of surfactant added was 4.5 mg per 1 g of PTFE.
The water repellency of the plating film was measured. The results are shown in Table 1 below.

[0025]

[Table 1] From the above results, it is understood that the composite plating solution of the present invention can form a plating film having excellent water repellency immediately after plating.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Mikio Sasabe 1150 Hazawacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Asahi Glass Co., Ltd. Central Research Laboratory (56) References JP-A-62-275190 (JP, A) JP-A-48 JP-A-49827 (JP, A) JP-A-5-33153 (JP, A) JP-A-7-26397 (JP, A) JP-T-62-502552 (JP, A) (58) Fields investigated (Int. . ^7, DB name) C25D 15/00 - 15/02 C23C 18/16 - 18/52

Claims (4)

(57) [Claims] 1. A composite plating solution comprising a cationic surfactant and a pitch fluoride in a plating solution. 2. A composite plating film in which pitch fluoride is eutectoidally formed on a substrate by an electroplating method using a plating solution containing a cationic surfactant and a pitch fluoride in the plating solution. A composite plating method. 3. The composite plating method according to claim 2, wherein heating and drying are not performed after plating. 4. A composite plating film obtained by eutecting pitch fluoride into a metal plating film.