JPH01119660A - Partial dry plating method - Google Patents

Abstract

PURPOSE:To obtain a part of the high ornamental value having the dry plating to prescribed selective parts or the two colors of the surface color of a substrate and the dry plating color by using a black chrome plating layer or black ruthenium layer for a partial mask to be used at the time of dry plating. CONSTITUTION:An org. resist 3 is previously coated to the prescribed part and after the resist is cured by baking, the wet plating films 4, 9 of the black chrome plating or black ruthenium plating are coated thereon. The org. resist 3 is then dissolved away by an org. solvent to form the substrate surface having the substrate color and the wet plating color; thereafter, the dry plating layer is formed on the surface and the wet plating film is stripped away. The overetching under the resist film and the exfoliation of the resist film or the generation of the interference color of the dry plating layer by the heat generated at the time of the dry plating and the decoloration of the substrate surface by the thermal diffusion of the substrate surface and the plating film for masking are, therefore, prevented and the parts of the high ornamental value having the dry plating to the prescribed selective parts or the two colors of the surface color of the substrate and the dry plating color are thus inexpensively obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of forming a dry plating layer on a selective predetermined portion of the surface of a metal/alloy or a metal/alloy coated with various wet platings.

[Summary of the invention]

The present invention is a method of selectively dry plating a predetermined portion of the surface of a substrate made of a metal/alloy or a metal/alloy coated with various wet plating, in which an organic resist is applied to the predetermined portion in advance. A chromium plating layer or a black ruthenium plating layer is coated after baking and hardening, and then the organic resist is dissolved and removed using an organic solvent to form a substrate surface in two colors, the substrate color and the wet plating color, and then dry plating is performed after the surface is coated. By forming a layer and then peeling off the wet plating film, it is possible to selectively dry plate a predetermined area or to provide an area with high decorative value having two colors, the substrate color and the dry plating color. .

[Conventional technology]

The conventional dry plating method for selectively predetermined areas is: (1) After forming a dry plating layer on the entire surface of the board, the unnecessary areas of the dry plating are mechanically removed.

■After forming a dry plating layer on the entire surface of the board, apply an organic resist to the areas that require a dry plating layer, and after curing by baking, chemically dissolve and remove the dry plating layer in unnecessary areas.
How to dissolve and remove resist.

■A method in which an inorganic heat-resistant paint is applied in advance to the important parts of the board surface for dry plating, baked and hardened, a dry plating layer is formed, and then the inorganic heat-resistant paint is dissolved and removed using a solvent.

■As shown in Japanese Patent Publication No. 61-117269, after forming a plating layer of nickel plating, copper plating, or an alloy thereof on the entire surface of the board, applying an organic resist to the important parts of the dry plating method and dissolving and removing the plating layer after baking and hardening. There is a known method in which the organic resist is then dissolved and removed, a dry plating layer is formed, and then the plating layer is dissolved and removed.

[Problem that the invention seeks to solve]

However, these methods have the following drawbacks.

With method (2), it is extremely difficult to remove unnecessary parts without damaging the dry plating layer that should be left in place in terms of mass production, and this becomes even more difficult as the surface shape of the substrate becomes more complex. Furthermore, if this is carried out after various wet plating layers have been formed on the surface of the substrate, there is a problem that the thickness of the wet plating layer decreases due to machining, making it impossible to guarantee the plating thickness.

In method (2), the smaller the area of the dry plating layer that is to be left, the more advantageous it is, but the smaller the area, the more difficult it is to apply the resist, and the adhesiveness between the substrate surface and the resist deteriorates. Furthermore, hydrofluoric acid-based chemicals are often used to remove the dry plating layer, which often causes overetching under the resist film and peeling of the resist film when removing the dry plating layer.

In method (2), the larger the area of the dry plating layer, the more advantageous it is, but due to the heat generated during dry plating, interference colors and color unevenness occur in the dry plating layer due to the gas inherent in the resist and the decomposition gas of the resist. . Additionally, the resist film may chip or peel, impairing the intended appearance.

In method (2), over-etching occurs under the resist film when a plating layer such as a nickel plating layer is peeled off after resist application. In addition, due to the heat generated during dry plating, nickel,
Copper or its alloy thermally diffuses onto the substrate surface, causing discoloration of the substrate surface. In addition, it takes a long time to peel off and remove a plating layer such as a nickel plating layer after dry plating, resulting in poor work efficiency. There were other problems. The present invention solves these problems by selectively performing dry plating on predetermined areas or by providing areas with high decorative value that have two colors: the substrate surface color and the dry plating color.

[Means for solving problems]

The present invention is a partial dry plating method for solving the problems mentioned above, in which a dry plating layer is formed on selective predetermined portions of the surface of a substrate made of metals/alloys or metals/alloys coated with various wet platings. In the dry method, an organic resist is applied to a predetermined area in advance, and after hardening by baking, a wet plating film of black chrome plating or black ruthenium plating is applied, and then the organic resist is dissolved and removed using an organic solvent. This method is characterized by forming a substrate surface of a substrate color and a wet plating color, then forming a dry plating layer on the surface, and then peeling off the wet plating film. Since the resist can be made of commercially available offset ink, silk printing and tacho printing are possible, and complex-shaped parts can be easily coated.

[Effect]

According to the above method of the present invention, by using a black chrome plating layer or a black ruthenium plating layer as a partial mask during dry plating, (1) a commercially available acid-resistant resist can be used as the resist for the partial mask during plating.

■There is no generation of gas due to the heat generated during dry plating, and there is no interference color in the dry plating color.

■The black chrome plating layer and the black ruthenium plating layer are chemically stable, so the heat generated during dry plating does not cause heat diffusion to the substrate surface, and no discoloration of the substrate surface occurs.

■ Peeling and removal of the black chrome plating layer or black ruthenium plating layer after dry plating is easy because there is no heat diffusion layer.

The present invention will be explained below based on examples.

[Example 1] Fig. 1 is a cross-sectional view of the surface treatment showing a watch case layout with a two-color finish of gold and gray-black by the partial dry plating method of the present invention, and each step of (a) to (f) is shown. This will be explained based on the diagram.

(a) In the watch case made of SUS304,
Coated with u-Ni alloy plating.

(b) An organic resist was applied using silk printing to a portion where a Ti-based gray-black ion blating layer was to be formed, and baked and hardened.

(C) A general plating pretreatment was performed in the order of alkaline degreasing → water washing → alkaline cleaning → water washing → acid washing → water washing → pure water washing, and then a 1μ black chrome plating was applied.

(d) The resist film was peeled off by immersion in a resist stripping solution to obtain a substrate surface having two colors, black and gold.

(e) After cleaning with an organic solvent, ion blating was performed to form a Ti-based gray-black ion blating layer.

(f) An anodic electric field was applied at a voltage of 5 V in an industrial concentrated phosphoric acid solution to completely peel off and remove the black chromium plating layer and the gray-black ion blating layer laminated thereon. At this time, discoloration occurred in the golden portion, so the discoloration was removed by immersing it in (1+1) hydrochloric acid solution.・The watch case with a two-color finish consisting of gold and gray-black treated using this method has been tested in artificial sweat corrosion resistance test (40°C x 90% humidity x 24H') and artificial seawater corrosion resistance test (40°C x 90% humidity x 24H') I '), bending test (90° bending), thermal shock test (200°C
x10m1n heating → water cooling), abrasion resistance test (set so that the border between the two colors is in contact with the cowhide, apply a load of 500g, and rub 30,000 times with a 5cm stroke), appearance (
The above test results all satisfied the quality as a watch case. In the above method, the conditions for ion blating are that prior to ion blating, ion bombardment is performed with argon gas at 10 Pa and a voltage applied to the substrate of 0.5 Kv, the substrate surface is cleaned, and then the argon gas is exhausted. After returning the inside of the vacuum chamber to 3XIO-'Pa, nitrogen gas and acetylene gas were again introduced as reactive gases at a ratio of 1:3 to 2x10-'Pa, and the substrate voltage was reduced to 0.
3 Kv and 5 mA were applied to generate plasma, and metal titanium was heated and evaporated using a board heating method, and a gray-black hard coating made of a compound of titanium, nitrogen, and carbon was laminated.

[Example 2] Figure 2 is a cross-sectional view of the surface treatment showing a two-color finish of white and blue using the partial dry plating method of the present invention. I will explain based on this.

(a) A watch case made of brass material was electroplated with 3 μm of nickel plating, and then plated with a palladium-nickel alloy of 3 μm.

(b) An organic resist was applied using tacho printing to a portion where a Ti-based blue ion blating layer was to be formed, and baked and hardened.

(C) A general plating pretreatment was performed in the order of alkaline resin → water washing → alkaline washing → water washing → acid washing → water washing → pure water washing, and then a black ruthenium plating of 0.5μ was coated.

(d) The resist film was peeled off by immersion in a resist stripping solution to obtain a substrate surface having two colors, black and white.

(e) After cleaning with an organic solvent, ion blating was performed to form a Ti-based blue ion blating layer.

(f) Anodic electrolysis was carried out at a voltage of 6 cm in a 1% caustic soda solution to completely peel off and remove the black ruthenium plating layer and the blue ion blating layer laminated thereon. At this time, since discoloration occurred in the white part, the discoloration was removed by immersing it in (1+1) hydrochloric acid solution. The watch case has a two-color finish of white and blue treated using this method.
The same artificial sweat corrosion resistance test, artificial seawater corrosion resistance test, bending test, heat shock test, abrasion resistance test, and appearance as in [Example 1] were conducted, and the results showed that the quality as a watch case was satisfied. In the above method, the conditions for ion blasting are as follows: After performing ion bombardment in the same manner as in [Example 1], oxygen gas is added as a reactive gas at 2×10 −
'Pa, a substrate voltage of 0.3 Kv was applied, plasma was generated, metallic titanium was heated and evaporated by a board heating method, and a blue hard coating made of a compound of titanium and oxygen was laminated.

〔Effect of the invention〕

As described above, according to the present invention, in the dry plating method on selective predetermined portions of the surface of a substrate made of a metal/alloy or a metal or alloy coated with various wet plating, organic After applying the resist and curing it by baking, cover with black chrome plating or black ruthenium plating, and then dissolve and remove the organic resist with an organic solvent to form a substrate surface of the substrate color and wet plating color. By forming a dry plating layer on the surface and then peeling off the wet plating film, it is possible to prevent overetching under the conventional resist film, peeling of the resist film, or interference color of the dry plating layer due to the heat generated during dry plating. It overcomes disadvantages such as discoloration of the substrate surface due to heat diffusion between the substrate surface and the masking plating film, and enables selective dry plating on predetermined areas or decorative value having two colors, the substrate surface color and the dry plating color. This has the effect of making it possible to provide expensive parts at low cost.

It can be applied not only to watch cases, but also to decorative parts such as eyeglass frames, lighters, buckles for decorative bands, and tie clips.

[Brief explanation of the drawing]

FIGS. 1(a) to (f) and FIGS. 2(a) to 2(f) are surface treatment cross-sectional views showing an embodiment of the partial dry plating method according to the present invention. 1... Stainless steel (SUS304) material 2... Au
-Ni alloy plating layer 3...Organic resist 4...Black chromium plating layer 5...Ti-based gray-black ion blating layer 6...
Brass material 7...Nickel plating layer + palladium-nickel alloy plating layer 8...Ti-based blue ion brating calendar 9...
・Applicant for black ruthenium plating layer and above Seiko Epson Co., Ltd. Representative Patent Attorney Kiri Mogami - 1 other person - 9.2znoy, :j

Claims (1)

[Claims] (1) In the partial dry plating method in which a dry plating layer is selectively formed on a predetermined portion of the surface of a substrate made of a metal or alloy coated with a metal or alloy or various types of wet plating, an organic resist is applied to a predetermined portion in advance. After baking and curing, black chrome plating or black ruthenium plating is applied, and the organic resist is then dissolved and removed using an organic solvent to form a substrate surface with two colors: the substrate color and the wet plating color. A partial dry plating method characterized by forming a dry plating layer on the surface and then peeling and removing the wet plating film.