JPS638585A - Rust protection for magnetic resistant dial for iron based timepiece - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a method for preventing rust of a magnetic dial plate for an iron-based watch. [Prior Art] The base material of a watch dial plate is generally made of a corrosion-resistant material. Previously, highly durable copper alloys (brass, nickel silver, phosphor bronze) were used, but in order to improve the protection of the watch movement against disturbance magnetic fields, conventional technology has introduced the use of iron-based materials in the construction of anti-magnetic dials. As shown in Figure 3 (a), decorative patterns are applied to the base material of electromagnetic soft iron and iron-based alloys (permalloy, etc.), and as anti-corrosion plating, surface treatment such as electroless nickel is applied. This was followed by regular decorative plating, and only the surface was treated with protective clear lacquer and colored paint.

Also, according to the utility model announcement, 1972-2108'3, as shown in Figure 5(b), a general watch dial (
Mainly copper alloy) back side K, iron and silicon, aluminum,
A evaporated layer of a highly magnetic material such as chromium, nickel, etc. (iJ') was formed, and the alloy was recrystallized by heat treatment to form a magnetically resistant dial plate.

Furthermore, as shown in Figure 6(c), as shown in the structure of the Utility Model Publication 1986-194086, three layers of clad material were used for the dial base material, electromagnetic soft iron was used for the middle layer, and the upper and lower layers were There have been examples of using copper alloys such as brass and nickel silver to improve the rust prevention effect.O [Problem to be solved by the invention] However, in the prior art described above, Fig. 3 (α), the following There were problems like.

(1) Iron-based alloys such as permalloy are hard and do not have the fine surface patterns of copper alloys, which has been a constraint.

(2) Because it is an iron-based material, it rusts easily during the process and is difficult to manage.

(3) The surface may be inactivated and the adhesion of the plating may be poor. (4) As anti-rust plating, use electrolytic nickel or electrolytic steel plating + electrolytic nickel plating equivalent to J Engineering 5-H3617 (plating symbol MFNiI~■). Even if 5 to 10 microns are formed or electroless nickel plating is applied to 3 microns or more, pinholes remain and rust is observed, especially from the back side where there is no finishing paint layer, as shown in Figure 2 (α). Does not satisfy weather resistance test for exterior parts.

The weather resistance test method is based on General Rules for Weather Resistance Tests for Automotive Parts J.
Using the accelerated test material (ultraviolet carbon fade meter) described in Tech. It varies depending on the standard, but 1
It is assumed that there is no change after irradiation for 00 to 200 hours.

The reason for keeping the inside of the case in a humidified state is to assume that in the worst case, water or sweat gets into the case.0 (5) By performing the treatment in (4) above, it will take a long time to form the plating. This method requires time, increases costs, and has problems with appearance and functionality due to the thick plating layer.

In addition, the prior art shown in FIG. 5(b) had the following problems: (1) The thickness of the vapor deposited layer (iron-based layer) was limited to several microns considering adhesion, etc. The magnetic shielding effect of a practical ring memory magnetic field of 60 Gauss cannot be ensured at all.

(2) In the structure of the invention, there was a problem that the above-mentioned light resistance test could not be satisfied because there was no anti-corrosion treatment layer of the iron-based vapor deposited layer.

Furthermore, the conventional technique shown in FIG. 3(c) has the following problems.

(1) It is necessary to cut the outside diameter of the dial and make holes to fix letters, marks, etc. to the dial, and this sheared part exposes the electromagnetic soft iron layer, so J rust plating is applied as described above. Even if applied, weather resistance cannot be ensured.

(2) The composition of the cladding material is a combination of iron and copper alloy, as shown in Figure 2 (6). In a humidified and electrolyte atmosphere, the iron-based layer with a high ionization tendency becomes the anode and the non-iron-based metal layer Since copper, which is a metal, acts as a cathode, electrochemical corrosion is accelerated and iron becomes susceptible to rust.

(3) In order to avoid the electrochemical corrosion mentioned above, it is desired to apply zinc plating, which has a higher ionization tendency than iron, to the dial metal surface to prevent rust, but various decorative platings on zinc plating are technically impossible and cannot be used. There is a problem.

SUMMARY OF THE INVENTION The present invention is intended to solve these problems, and its purpose is to provide a highly reliable rust prevention method for magnetic dials for iron-based watches.

[Means for solving problems]

The method for preventing rust of an iron-based magnetic dial for a watch according to the present invention comprises:
Patterns such as radiation and streaks, various decorative plating, finishing coating, etc.
After normal surface treatment, galvanizing or a composite layer of galvanizing and chromate is formed only on the back surface.

According to the present invention, the pattern side is coated with a finishing paint that has excellent weather resistance and chemical resistance from among various paints (e.g., polyurethane, acrylic, epoxy, polyester, etc.).
After selecting one type of protective coating from among them, galvanize only the back side by selecting one type of galvanizing coating such as pyrophosphoric acid bath type, sulfuric acid bath type, cyanide bath type, etc., or apply dichromic acid bath after the zinc plating. Alternatively, a chromate layer is formed by chromate treatment with a dichromate-based solution.

As a result, the patterned side of the dial is protected with a finish paint that has excellent weather and chemical resistance, so the appearance of the patterned side is not impaired in any way, and the paint will not peel off due to plating or chromate treatment. Predetermined processing can be performed. Also,
It has been found that, in addition to the paint itself, poor control conditions in the plating process have a large effect on quality KM. The rust prevention method of the present invention can be established by suitable conditions for galvanizing to a thickness that does not cause the paint to peel off due to the generation of hydrogen gas by electrolysis of H and O in the plating solution, and plating that does not cause pinholes. be.

The present invention will be specifically described below based on Examples.

[Example-1] As shown in the configuration diagram in Figure 1(a), the first iron-based layer, electromagnetic soft iron or iron-nickel alloy (permalloy) with a thickness of 05 mm, is coated with an outer diameter wave corresponding to the design and 50 characters. After machining such as punching holes, attaching supports in 6, and polishing the surface, necessary patterns such as radial moyo, streaks, satin finish, etc. are applied, and the electroless nickel plating that forms the decorative plating layer in 3 is 1 micron thick. Then, apply 0.1 micron electroless gold plating for decoration.

Next, a second finishing paint layer (polyurethane type, etc.) with excellent weather resistance and chemical resistance is spray coated with a thickness of 5 to 10 microns.
Bake dry at 40°C for 30 minutes.Additionally, composite treatment of 5 micron zinc plating and colored chromate according to the composition conditions shown in Tables-1 and -2 (J-K5-H3610, symbol MF Z n - After printing and typesetting (equivalent to TIC), it was completed.

Table-1 Composition and conditions of galvanizing -2 Composition and conditions of colored chromate [Example-2] As shown in Figure 1(b), one iron layer was coated with an electromagnetic soft iron plate having a thickness of 01
Copper and copper alloys constituting the non-ferrous metal layer in words 5 and 7 (
The same processing as in Example 1 was carried out using a three-layer clad material with a total thickness of 0.3 mm (brass, nickel silver, etc.) or nickel.

However, depending on the required quality, the chromate treatment may be omitted.

Table 5 shows the results of the weather resistance test and porosity test for Example 1.2. It is highly reliable and has a significantly improved quality level compared to conventional technology.

In particular, in the prior art, as shown in FIG. 2, a large amount of brownish red rust was generated from the back side where there was no finishing paint layer, and appeared on the surface of the dial, detracting from its appearance.

*(1) Using Suga Test Co., Ltd. (Standard Ultraviolet Long Life Fade Meter FAL-5) (2) Watch test case (wet atmosphere) ○ No abnormalities △ Slight rust × Significant rust [Effects of the invention] As stated above According to the present invention, after the base material of the iron-based antimagnetic dial is subjected to normal surface treatments such as patterning such as radiation and streaks, various decorative plating, and finishing coating, only the back side is galvanized or galvanized. The following effects were obtained by forming a composite film with chromate film.

(1) In conventional techniques, metals such as copper, nickel, electroless nickel, etc., which are more susceptible to ionization than iron, are used as anti-rust plating due to surface finish, and as a result, electrochemical corrosion is unavoidable.

The present invention solves these problems and provides a magnetically resistant dial plate with good weather resistance and high reliability.

(2) Since the dial can achieve high anti-magnetic performance, special parts such as anti-magnetic plates and frames are no longer required, making it possible to make watches thinner and reduce costs.

As described above, the practical effects of the present invention are extremely large.

[Brief explanation of drawings]

FIG. 1 (α) is a sectional view of the dial structure of Example 1 of the present invention. FIG. 1(b) is a cross-sectional view of the dial plate configuration of Embodiment 2 of the present invention. 1... Iron-based layer 2... Finishing paint layer 3... Decorative plating layer 4... Galvanized layer or zinc plating + chromate layer 5... . . . Character hole punching portion 6 . . . Supporting foot 7 . . . Metal layer other than iron-based. . 8...Corrosion occurrence part FIG. 3(a)+(M)+(c) is a sectional view of the dial structure of the prior art. Ell Seiko Epson Corporation Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] The base material of the iron-based anti-magnetic dial, which is made of iron or an alloy of iron and other metals, is subjected to normal surface treatments such as patterning such as radiation and streaks, various decorative plating, and finishing coating, and then only the back side is galvanized or A rust-preventing method for magnetic dials for iron-based watches, characterized by forming a composite layer of zinc plating and chromate layers.