JPH11193493A - Nickel-less plated product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cover the defects such as flaws of the ground and to prevent the cracking of a finish plating and the corrosion of a substrate plating by forming an Ag plating layer of specified thickness as the substrate plating of the ground. SOLUTION: The thickness of the Ag plating layer is controlled to 0.1-30 μm, and an intermediate plating layer consisting of a platinum-group metal selected from Ru, Rh, Pd, Os, Ir and Pt and a finish plating layer are formed thereon to prevent the corrosion and discoloration of the Ag plating layer due to sulfidization, etc. A plating having 0-5 μm thickness and consisting of Au, Au alloy, Cr or Cr alloy is applied as the finish plating layer, however the thickness is increased to >=5 μm in the case of a high-grade article. When the intermediate layer of a platinum-group metal having 1 to 2 μm thickness is formed, a highly corrosion-resistant white plating is used, and the finish plating layer can be omitted. Since the substrate-layer plating is free of nickel, allergy to nickel is not caused by the trinkets, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating layer structure in a nickel-less plated product, and more particularly, to prevent defects such as scratches and clouding of the fabric, and furthermore, there is no crack or discoloration in the finished plating layer and corrosion is generated. Nickel-less plated product having no underlying plating layer.

[0002]

2. Description of the Related Art Conventionally, in various accessories such as wristwatches, earrings, glasses, necklaces, pendants, rings, etc., it is possible to eliminate defects such as scratches on the fabric and to improve plating coverage. For this reason, an undercoating layer containing nickel is usually applied after Cu plating, but an undercoating layer instead of nickel has been used in recent years from the viewpoint of preventing nickel allergy. For example, Cu-Sn or Cu- Sn-Zn alloy plating is used. However, Cu-Sn or Cu-Sn-Z
The n-plating is a plating having a high internal stress, and when these are base-plated, cracks often occur in the finish plating.

[0003] The present invention solves the above problems,
The purpose is to provide a base plating that covers defects such as scratches on the fabric in nickel-less plated products and that does not cause cracks in the finish plating,
An object of the present invention is to prevent the corrosion of the undercoat.

[0004]

The object of the present invention is to provide a ring, a necklace, an earring, a pendant, a broach,
An Ag plating layer according to claim 1 for a plating cloth of various accessories such as a wrist watch, a band, and glasses.
This is achieved by applying m as a base plating.

[0005] Ag plating is provided as a base plating layer that covers defects such as scratches on the cloth (material).
If the thickness is less than μm, the object cannot be achieved, and when a platinum group plating or the like is formed on the underlying plating layer, adhesion to the plating layer is poor. On the other hand, the thickness of the Ag plating layer is sufficient up to about 30 μm. Even if the thickness is further increased, the effect is not improved so much and the cost increases.

The Ag plating layer is liable to be denatured or discolored by corrosion due to sulfurization or the like, but in order to prevent this, in the present invention according to claim 2, Ru, Rh, Pd, and Os are further added to the invention according to claim 1. , Ir and Pt are provided with an intermediate plating layer and a final plating layer of 0.01 to 5 μm of a platinum group metal of 0.01 to 5 μm of a platinum group metal selected from the group consisting of Ir and Pt.

As described above, the intermediate plating of the platinum group metal is provided for the purpose of preventing corrosion and discoloration of the Ag plating portion. However, if the thickness is less than 0.1 μm, the intended effect cannot be sufficiently obtained. On the other hand, when the thickness is 5 μm or more, the plating is easily broken due to the internal stress of the platinum group plating, and the cost increases.

[0008] Further, in the present invention according to claim 3,
In the invention according to the second aspect, a plating layer made of Au, an Au alloy, Cr or a Cr alloy having a thickness of 0 to 5 μm is applied as a finish plating layer.

The finish plating is applied for the purpose of improving corrosion resistance and appearance, and usually a sufficient effect can be obtained at 5 μm or less. However, in the case of a high-grade product, the thickness may be 5 μm or more. In addition, the intermediate plating layer of platinum group metal is
By plating with a thickness of at least μm, it is possible to finish with white plating having good corrosion resistance. In this case, the finish plating layer can be omitted.

The present invention can be applied to electronic parts such as lead frames in addition to the various accessories described above, and can be applied to fabrics of arbitrary materials. In the case where the cloth has pinholes or nests or in the case of plastic plating, it is preferable that the cloth be plated in advance with copper. In this case, copper is plated at 3 μm to 50 μm depending on the degree of the material. A more beautiful appearance can be obtained by silver plating after tens of μm of copper plating and buffing.

[0011]

EXAMPLE 1 A plastic watch case made of ABS resin was plated with copper by a conventional method to a thickness of 15 μm. On this copper plating layer, silver plating having the following composition was plated at a thickness of 5 μm, and further, palladium plating was plated at a thickness of 0.5 μm, and chromium plating was plated at a thickness of 0.25 μm.

Silver plating composition Silver bluing 40 g / l Sodium bluing 120 “Sodium carbonate 15” Commercial brightener 4 cc / l Commercial curing agent 10 cc / l Temperature 25 ° C. Current density 1 A / dm ²

In this case, a 24-hour artificial sweat test, a 24-hour ammonia aeration test, and 80 ° C.
No discoloration, cracks, and other defects were found in a 30 minute immersion in water and a 10 minute quenching test with 20 ° C. water.

Artificial sweat composition Salt 9.9 g / l Sodium sulfide 0.8 g / l Urea 1.7 g / l Ammonia water 0.18 cc / l Sucrose 0.2 g / l Lactic acid 1.1 cc / l Distilled water Total volume 1 liter Ammonia test The test sample was put into a commercially available desiccator containing a 2: 1 mixture of ammonia water and water and aerated.

[0015]

Example 2 A watch case made of Zn die-cast was plated with copper by a conventional method to a thickness of 20 μm. Silver plating having the composition shown in Example 1 was applied to a thickness of 10 μm, and palladium was further applied to a thickness of 3 μm. When the watch case was subjected to a 24-hour artificial sweat test and an ammonia aeration test, no abnormalities such as discoloration and cracks were found.

[0016]

[Comparative test] A watch case similar to that in Example 2 was coated with Cu-Sn plating at a thickness of 5 µm instead of silver plating, and a similar test was performed. As a result, cracks were generated. Had occurred.

[0017]

EXAMPLE 3 A neck chain made of brass was plated with copper to a thickness of 3 μm, silver plating having the same composition as in Example 1 was applied to a thickness of 3 μm, platinum was plated to a thickness of 0.5 μm, and gold was plated to a thickness of 3 μm. Then, they were sequentially formed. No abnormalities were found in either the artificial sweat test or the ammonia aeration test.

[0018]

Example 4 After pretreatment of a lead frame made of phosphor bronze, silver plating was applied to a thickness of 3 μm using the same composition as used in Example 1 but without a hardener, followed by pure palladium plating. Was plated with a thickness of 0.02 μm.

Pure palladium plating composition Ammonium chloride 50 g / l Dipotassium phosphate 50 g / l Palladium chloride 3 g / l Aqueous ammonia pH 8.0 The lead frame was heated at 500 ° C. for 10 minutes. Did not. The solderability was also good.

Claims (3)

[Claims] 1. A nickel-less plated product having an Ag plating layer of 0.1 to 30 μm as a base plating for a fabric. 2. An underlying plating layer comprising an Ag plating layer having a thickness of 0.1 to 30 μm, and 0.01 to 5 of a platinum group metal selected from the group consisting of Ru, Rh, Pd, Os, Ir and Pt.
Nickel-less plated product consisting of a μm intermediate plating layer and a finish plating layer. 3. A method according to claim 1, wherein the finish plating layer has a thickness of 0 to 5 μm.
3. The plating layer structure according to claim 2, comprising a u alloy, Cr or a Cr alloy.