JPS629675B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an outer cutter for an electric shaver made of a nickel-manganese alloy electrodeposit or a nickel-manganese-cobalt alloy electrodeposit.

Generally, outer blades for electric razors are made by electrodeposition from an electrolytic solution containing nickel ions, and organic brighteners containing sulfur atoms, such as saccharin and sodium naphthalene trisulfonate, are added to the electrolytic solution. This gives surface gloss to the formed outer blade made of nickel electrodeposit and reduces internal stress to prevent peeling and deformation during electrodeposition formation.

It is well known that the use of such organic brighteners generally increases the hardness of the outer blade and prevents wear caused by sliding of the opposing blade (inner blade), but on the other hand, the heat generated by sliding during use The drawback was that when the metallographic structure was gradually heated to high temperatures, the metallographic structure changed and the toughness was severely impaired. For example, if a material with an initial Vickers hardness of about 550 is heat-treated at 230°C for 30 minutes, its toughness deteriorates to the point where the Vickers hardness cannot be measured, making it susceptible to cracking.

In this way, with conventional outer blades, the effect of sliding heat during use tends to become noticeable at around 230℃, and this is true for the outer blades after heat treatment as described above.
This can be inferred from the fact that the cross-sectional structure is very similar to that of the one that actually cracked during use.

The purpose of this invention is to provide an outer blade for electric razors which is free from such drawbacks and has excellent thermal stability. In forming the outer cutter, an inorganic brightener is used as the brightener, and manganese ions are included in the electrolyte to form the outer cutter into a nickel-manganese alloy electrodeposited material.

Figure 1 shows the thermal change in hardness of the nickel-manganese alloy electrodeposited material of this invention with a manganese atomic content of 0.6% by weight. There is almost no decrease in hardness, and there is no major change in the microstructure accompanied by deterioration of toughness, unlike the conventional outer cutter, which cracked during hardness measurement.

Such good thermal stability is also observed when the manganese atom content is usually 0.2% by weight or more. On the other hand, in an outer cutter made of this type of alloy electrodeposit, the initial hardness generally tends to be low because the inorganic brightener used has almost no function of increasing hardness. Increasing the manganese atom content improves the initial hardness. However, if this amount is too large, the internal stress of the outer cutter becomes large and there is a risk that cracks may occur during electrodeposition formation.

The inventors have found that the initial hardness can be greatly improved by including cobalt ions together with manganese ions in the electrolytic solution to form a nickel-manganese-cobalt alloy electrodeposit.

Figure 2 shows a comparison of the hardness and thermal changes of the outer cutter made of such a ternary alloy electrodeposit and the outer cutter made of the binary alloy electrodeposited material. For a ternary alloy electrodeposit with an atomic content of 10% by weight, curve - is for a ternary alloy electrodeposit with the same content of 36% by weight, curve - is for a binary alloy electrodeposit, and the manganese atomic content is Both are 0.3% by weight.

From this figure, it is clear that the initial hardness can be increased by including cobalt atoms, and this increase phenomenon is observed when the cobalt atom content is 10% by weight or more, and becomes more pronounced as the content increases. .

Furthermore, as is clear from the figure, even when a ternary alloy electrodeposited material is used, the good thermal stability observed in the binary alloy electrodeposited material is still maintained. However, if the cobalt atom content is too high, the toughness will decrease and the internal stress will increase, which may cause flaking during electrodeposition.
It is desirable to keep it within the range of 50% by weight. Within this range, the thermal stability of at least the conventional outer cutter made of nickel electrodeposited material can be sufficiently improved.

Figure 3 shows the relationship between the internal stress and manganese atomic content of the outer cutter made of such a ternary alloy electrodeposit, and as is clear from this figure, the manganese atomic content is usually 0.6% by weight. If the internal stress is within this range, there is no risk of problems such as flaking or cracking occurring during electrodeposition.

In this way, when forming the outer cutter made of the nickel-manganese-cobalt alloy electrodeposited material in this invention, the manganese atomic content is usually 0.2 to 0.6% by weight.
and the cobalt atomic content is usually 10-50% by weight.
It is desirable to do so. This outer cutter has low internal stress and high hardness of at least 450 on the Vickers hardness scale, and has excellent thermal stability.

The electrolytic solution applicable to this invention includes various types of conventionally known electrolytes, and representative ones include Watt's bath and sulfamic acid bath.

Typical inorganic brighteners added to the electrolytic solution include nickel formate, magnesium sulfate, nickel acetate, and magnesium sulfamate. Among these, nickel formate and magnesium sulfate are most preferred.

As mentioned above, such inorganic brighteners have almost no function of lowering the hardness of the outer blade like conventional organic brighteners, but they do have the function of imparting surface gloss and the function of reducing internal stress. are doing. The amount used varies depending on the type of brightener; for example, for nickel formate, it is usually sufficient to include 10 g/or more, and for magnesium sulfate, it is usually 30 g/or more.

Further, an appropriate manganese salt or a cobalt salt and a manganese salt depending on the type of the electrolytic solution are added and dissolved to contain manganese ions or cobalt ions in the electrolytic solution.

The content of manganese atoms or cobalt atoms in the alloy electrodeposit increases approximately in proportion to the ratio of manganese ions or cobalt ions to nickel ions in the electrolyte. Therefore, the manganese salt or cobalt salt added to the electrolyte should be selected by taking into account the nickel ions dissolved in the electrolyte and electrodeposition conditions such as current density and stirring conditions.
The amount used may be determined so that the content of manganese atoms or cobalt atoms in the alloy electrodeposit becomes desired.

When a known electrodeposition method is applied to the electrolytic solution containing nickel ions, manganese ions, or cobalt ions and an inorganic brightener added thereto, it is possible to obtain an electrolyte with the excellent performance described above. An outer blade for a razor is obtained.

The method for manufacturing the outer blade for electric razors of the present invention will be specifically explained below based on Examples.

Example 1 Nickel sulfamate 120g / Manganese sulfamate 160g / Nickel formate 40g / Nickel bromide 5g / Boric acid 40g / Formalin 3c.c. / Magnesium sulfate 50g / PH 3.8 Bath temperature 50℃ Current density 6A/dm ² Surface activity Agent (Pitutress S) 3 ml/A nickel-manganese alloy electrodeposited with a thickness of 120μ and a manganese atomic content of 0.6% by weight was electrodeposited in a net shape using the above electrolytic solution and electrolytic conditions for about 1.8 hours according to a conventional method. An outer blade for an electric razor was obtained.

The results of examining the thermal change in hardness of this outer cutter were as shown in FIG.

Comparative Examples Nickel sulfamate 450g / Nickel bromide 5g / Boric acid 35g / Sodium naphthalene trisulfonate 15g / 2-butyne-1,4-diol 0.1g / PH 4 Bath temperature 50-55℃ Current density 6A/dm ² Above An outer blade for an electric shaver made of only nickel electrodeposited was obtained using the same electrolytic solution and electrodeposition conditions as in Example 1. The Bitkers hardness of this outer blade is
523, but after heat treatment at 230°C for 30 minutes, cracks occurred during hardness measurement.

Example 2 Nickel sulfamate 405-440g / Cobalt sulfamate 10-45g / Manganese sulfamate 80-240g / Nickel formate 40g / Nickel bromide 5g / Boric acid 40g / Formalin 3c.c. / Magnesium sulfate 50g / Surfactant (Pitutress S) 3ml/PH 3.8 Bath temperature 50℃ Current density 6A/dm ² Nickel-manganese-cobalt alloy was electrodeposited to a thickness of 120μ using the same procedure as in Example 1 using the above electrolyte and electrodeposition conditions. No.1 and No.2 made of electrodeposited material
Two types of outer blades for electric razors were obtained.

The cobalt atom content of No. 1 outer cutter was 10% by weight and the manganese atom content was 0.3% by weight, and the cobalt atom content of No. 2 outer cutter was 36% by weight and the manganese atomic content was 0.3% by weight. . The hardness of these outer cutters and their thermal changes were investigated and the results were as shown in Figure 2. In the figure, the curve - is No. 1, the curve - is
This is the case No. 2.

In FIG. 2, the curve "-" is shown for reference with respect to an outer blade made of a nickel-manganese alloy electrodeposited material having a manganese atom content of 0.3% by weight, obtained according to the method of Example 1.

In addition, using the electrolytic solution and electrodeposition conditions described above, outer blades were formed from several types of nickel-manganese-cobalt alloy electrodeposit with a cobalt atom content of 20% by weight and various manganese atom contents. The results of investigating the relationship between the internal stress and the manganese atomic content are shown in Figure 3.

[Brief explanation of the drawing]

FIG. 1 is a characteristic diagram showing the thermal change in hardness of an electric razor outer blade made of a nickel-manganese alloy electrodeposited material manufactured by the method of the present invention, and FIG. 2 is a characteristic diagram of the present invention in which the manganese atomic content is 0.3% by weight. No. 3
This is a characteristic diagram showing thermal changes in hardness of outer blades for electric razors, in which the curve - and the curve - are for a nickel-manganese-cobalt alloy electrodeposit, and the curve - is for a nickel-manganese alloy electrodeposit. Also the third
The figure shows nickel manufactured by the method of this invention.
FIG. 2 is a characteristic diagram showing the relationship between the manganese atomic content and internal stress of an outer blade made of a manganese-cobalt alloy electrodeposit.

Claims (1)

[Scope of Claims] 1. When forming an outer blade for an electric razor by an electrodeposition method from an electrolytic solution containing nickel ions and adding a brightening agent thereto, an inorganic brightening agent is used as the brightening agent and the electrolytic solution A method for producing an outer cutter for an electric razor, characterized in that the outer cutter is made of a nickel-manganese alloy electrodeposited material by impregnating manganese ions therein. 2. The method for manufacturing an outer blade for an electric razor according to claim 1, wherein the inorganic brightener is selected from nickel formate, magnesium sulfate, and magnesium sulfamate. 3. A method for manufacturing an outer blade for an electric shaver according to claim 1 or 2, wherein cobalt ions are included together with manganese ions in an electrolytic solution to produce a nickel-manganese-cobalt alloy electrodeposit. 4 Manganese atom content in alloy electrodeposit is 0.2 to 0.6
The method for manufacturing an outer cutter for an electric razor according to claim 3, wherein the cobalt atom content is 10 to 50% by weight.