JPH0244917B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for treating spoons or forks with black electrodeposition coating, which allows the spoons or forks to be coated with black electrodeposition coating having a good appearance.

Prior Art and Problems to be Solved by the Invention Conventionally, electrodeposition coating has been applied to the surface of a workpiece for the purpose of imparting a beautiful appearance or improving corrosion resistance. When forming a coating using this electrodeposition coating, the object to be treated is supported with a conductive jig, and the electrodeposition coating is applied while applying electricity to the object from this jig. No coating film is formed on the parts (contact points) that the jig contacts. For this reason, when supporting the workpiece with a jig, we try to use the jig to support areas such as the back side of the workpiece where it is not noticeable even if a coating film is not formed. In some cases, such measures may be difficult. In fact, the inventors tried electrocoating the entire spoon or fork, but no matter which part was supported with a jig, no coating film was formed on the supported part, especially in the case of black paint. Since the uncoated portions were conspicuous, it was not possible to form an electrodeposition coating film with a good appearance. For example, Figures 1 and 2 show a state in which the neck 2 of a spoon 1 is supported by a jig 3, and the coating film 4 is neatly formed on the entire spoon 1 except for the neck 2, which is supported by the jig 3. As shown in FIG. 3, no coating film is formed on the neck portion 2, resulting in a non-coating portion 5, which significantly impairs the appearance.

The present invention was made in view of the above circumstances, and in the neck part that supports a spoon or fork with a jig,
An object of the present invention is to provide a method for black electrodeposition treatment of a spoon or fork, which can easily and reliably form a black electrodeposition coating film with a good appearance on the spoon or fork without making the uncoated part stand out. .

Means and operation for solving the problems That is, in order to achieve the above object, the present invention applies black electrodeposition coating to a stainless steel spoon or fork to form a black electrodeposition coating film on the surface of the spoon or fork. When coating a spoon or fork with black electrodeposition, a black conductive film is formed on the neck of the spoon or fork supported by a jig using a black chrome plating method, a black nickel plating method, or a black oxidation method. , black electrodeposition coating is applied.

According to the present invention, when electrocoating a stainless steel spoon or fork black, first, the neck supported by a jig is coated with black by black chrome plating, black nickel plating, or black oxidation. After a conductive film is formed, the neck on which the black conductive film is formed is supported with a jig and black electrodeposition is applied.Since the film has good conductivity, it is suitable for use on spoons and forks. Electricity is applied in the same way as when black electrodeposition is applied without forming a film, and a good black electrodeposition is applied, and the supporting parts of spoons and forks are Since the neck is located in the middle of the neck, it has good electrical conductivity and the coating film has good throwing power. Moreover, since the black conductive coating on the neck is supported by a jig, no black electrodeposition coating is formed, but since this area is black, there is no difference in color between it and the black electrodeposition coating. It is not noticeable,
There is no problem of poor appearance due to jig marks.

The present invention will be explained in more detail below.

In the black electrodeposition coating method for stainless steel spoons or forks according to the present invention, first, before electrocoating, the neck, which is supported by a jig, is coated with black chrome plating, black nickel plating, etc. A black conductive film is formed by a black oxidation method or a stainless steel black oxidation method.

In this case, the conductive coating may be formed only on the neck, or may be formed on a desired portion including the neck, or on the entire surface. Further, the black chrome plating method, the black nickel plating method, and the black oxidation method for stainless steel can be carried out by employing known methods. Note that the thickness of the conductive film is preferably 0.1 to 20 μm.

In the present invention, after forming a black conductive coating on at least the neck of the spoon or fork,
Black electrodeposition coating is applied to the neck while supporting it with a jig.
In this case, the electrodeposition coating may be anionic electrodeposition coating or cationic electrodeposition coating, but cationic electrodeposition coating is preferable from the viewpoint of paintability. In the present invention, the bath and coating conditions used for black electrodeposition coating are as follows:
Commonly used black electrodeposition coating baths and conditions can be used. The thickness of this coating film is also not limited, but it is usually preferably 10 to 20 μm.

In the present invention, when performing black electrodeposition coating, the neck portion on which the black conductive film is formed is supported by a jig. There is no problem when painting, and there is no black electrocoating film formed on the parts that are supported by this jig and hit by the jig, but as mentioned above, the black electrocoating film is the same color as the black electrocoating. Since a protective film is formed, the appearance will not be impaired.

After the electrodeposition coating, an appropriate post-treatment can be carried out if necessary, and a clear coating film can be further formed on the black electrodeposition coating film.

Effects of the Invention According to the present invention, the neck portion of a stainless steel spoon or fork that is supported by a jig when electroplated with black color is coated using a black chrome plating method in advance.
Since a black conductive film was formed by the black nickel plating method or the black oxidation method, a good black electrodeposition coating was obtained, which was equivalent to when supporting a spoon or fork by the neck without forming such a film. A quality black electrodeposited coating is formed. In addition, although no paint film is formed on the neck supported by the jig, the neck is the same black as the paint film, so it is not noticeable, and there is no deterioration in appearance due to jig marks, resulting in a good appearance. have

EXAMPLES Hereinafter, examples will be shown to specifically illustrate the present invention, but the present invention is not limited to the following examples.

Example 1 After pre-treating a stainless steel spoon using a conventional method, the entire surface was coated with nickel strike plating, and then a 5 μm thick nickel plating was applied, followed by black plating using a black chrome plating solution with the following composition. Chrome plated.

Black chrome plating composition, plating conditions composition Chromic acid 300g/glacial acetic acid 3g/urea 3g/Plating conditions Temperature 25℃ Cathode current density 50A/dm ² Plating time 3 to 5 minutes Next, the first, As shown in Figure 2, the neck of the spoon was supported with a jig and painted with black cationic electrodeposition.

Cationic electrodeposition coating bath, coating conditions electrodeposition coating bath Epoxy resin solid content (cationic type black)
18% organic acid 10ml/Cellosolve solvent 10ml/Electrodeposition coating conditions Bath temperature 28±1℃ Bath voltage 120V Current density 1A/dm ^{2 or} less Current time 1 minute Baking drying conditions Temperature 180℃ Time 20 minutes Black color by the above method When we observed the spoon on which the electrodeposited coating had been formed, we found that the neck of the spoon, which was supported by a jig, was not completely coated with the electrocoated coating; As a result, the absence of an electrodeposition coating film is not noticeable, and the overall black appearance is good, especially when a clear coating film is formed on top of it. It was difficult to tell the difference.

Example 2 Plating and cationic electrodeposition were carried out on a stainless steel spoon in the same manner as in Example 1, except that instead of black plating in Example 1, a 2 μm black nickel plating was applied with the following composition and conditions. Ta.

Black nickel plating composition, plating conditions composition Nickel sulfate 70g/nickel ammonium sulfate 40g/zinc sulfate 25g/sodium thiocyanate 20g/PH 5.0 Plating conditions Temperature 55℃ Cathode current density 1.0A/dm ² Plating time 10 Example 3 A stainless steel spoon was pretreated by a conventional method, and then its entire surface was colored black using an acidic black oxidation method. The bath composition and treatment conditions used in the acidic black oxidation method are shown below.

Acidic black oxidation method composition and treatment conditions Bath composition Sulfuric acid 180 parts Sodium dichromate 50 parts Water 200 parts Treatment conditions Temperature 95°C Immersion time 30 minutes Next, black cationic electrodeposition coating was applied in the same manner as in Example 1. provided.

In both of the spoons obtained in Examples 2 and 3, the absence of electrodeposition coating was not noticeable, and the spoons had a good overall black appearance.

In Example 3, similar results were obtained when the alkaline black oxidation method was used instead of the acidic black oxidation method.

Example 4 A stainless steel spoon was pretreated in a conventional manner, and then nickel strike plating was applied to its entire surface.

Next, taking advantage of the excellent alkali resistance and chemical resistance of the cationic electrodeposition coating bath of Example 1, a fourth coating bath was prepared.
As shown in the figure, alkali-soluble resist ink is printed on the parts of the spoon 1 that are not desired to be electrodeposited using a screen printing method to form resist coatings 5 and 5.
was formed. The tip of the spoon 1, including the neck 2, was immersed in the black chrome plating bath of Example 1 and plated to form a black plating film 6 only on the tip of the spoon 1. Next, black cationic electrodeposition coating was performed in the same manner as in Example 1. the result,
As shown in FIG. 5, the electrodeposition coating film 4 was not formed in the areas where the resist films 5, 5 were formed.

Subsequently, after immersing this spoon in a caustic soda solution to dissolve and remove the resist coatings 5, 5,
This part was coated with glossy nickel plating using a brush plating process, and then gold plating was applied.

As shown in FIG. 6, the obtained spoon had gold plating films 7, 7 formed on some parts, and was black on other parts, and was highly decorative. In addition, since the black chrome plating film 8 was formed on the jig support part during electrodeposition coating, it was not noticeable, and no appearance defects were caused in the black part.

[Brief explanation of the drawing]

Figure 1 is a front view of the neck of the spoon supported by a jig, Figure 2 is an enlarged cross-sectional view taken along the line shown in Figure 1, and Figure 3 is the conventional method shown in Figures 1 and 2. 4 to 6 are front views showing the state of the spoon after the neck of the spoon is supported by a jig to form an electrodeposition coating film, and FIGS. 4 to 6 respectively show cases in which an embodiment of the method of the present invention was applied to the spoon. FIG. 3 is a front view sequentially illustrating changes in the appearance of the spoon in different cases. 1...Spoon, 2...Neck. 3...Jig,
4... Paint film.

Claims (1)

[Claims] 1. When applying black electrocoating to a stainless steel spoon or fork and forming a black electrocoating film on the surface of the spoon or fork, support the spoon or fork with a jig when applying black electrocoat to the spoon or fork. After forming a black conductive film on the neck by black chrome plating method, black nickel plating method, or black oxidation method,
A method for treating a spoon or fork with black electrodeposition coating, the method comprising applying black electrodeposition coating.