JPH0553159B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a cutlery, more specifically a cutlery whose blade is coated with amorphous ceramics with a thickness of 1 μm or less, which is sharp and does not require sharpening, and furthermore, amorphous hydroxyapatite. This relates to cutlery whose blades are coated with a thickness of 1 μm or less.

BACKGROUND TECHNIQUES Carbon steel has traditionally been widely used as a cutting tool. Carbon steel has the advantage of being a rich material, cutting well, and being easy to produce, but if left unused after use, it will quickly rust, and if you cook with rusty knives, iron will be mixed in and the taste will deteriorate. Also, since the cutting edge has minute irregularities due to the material itself, it will not be sharp if used as a knife as is. Therefore, constant sharpening is required to adjust the rust and minute irregularities on the cutting edge and make it flat. However, sharpening requires experience, and constantly sharpening is complicated, and it is often the case that the sharpness of a knife that has been sharpened with the intention of improving its sharpness actually deteriorates. Because sharpening is a complicated operation and requires experience, knives made of stainless steel are used instead of steel because they last a long time without rusting, no matter how many times they are used. Stainless steel knives do not rust, but because they are harder than steel, it is difficult to sharpen the minute irregularities on the cutting edge to make it flat, and the cutting edge is slow. In this way, because of the minute irregularities on the cutting edge of the material itself, the force is not applied uniformly to the edge of the blade, resulting in a loss of sharpness. It is necessary to keep it sharp. Recently, in order to further add corrosion prevention, durability, hardness, sharpness, smooth texture, etc., the toxicity of nickel has also started to be a problem, so ceramics,
Blades coated with polymers, ceramic blades, or nickel-free blades are beginning to be used. Coating increases the hardness of the base material and lengthens the time from one polishing to the next, but if used forcibly, the coating material may peel off or the ceramic may spill due to the thick coating layer. For this reason, products with multilayer coating are also used. On the other hand, these knives are difficult to sharpen because they are hard, and it is difficult to adjust the minute irregularities on the cutting edge to a flat surface, and because the blades cannot be made as thin as metal knives, they tend to lack sharpness. As mentioned before,
BACKGROUND ART In order to improve the poor sharpness caused by minute irregularities in the material of the cutting edge of a knife, it is necessary to sharpen any knife, and various sharpeners have been devised. Therefore, if it is possible to flatten the minute irregularities of the material of the cutting edge without sharpening it, it is expected that a knife with good sharpness that does not require a sharpener can be obtained.

Problems to be Solved by the Invention In the present invention, the cutting edge is processed to be flat and thin, so force is applied uniformly to all of the cutting edges, resulting in good sharpness.In addition, the cutting edge is hard and does not wear out and does not rust, so it is not as sharp as conventional knives. This provides a sharp knife that does not require sharpening.

Means for Solving the Problems As mentioned above, there are blades in which stainless steel or steel base materials are coated with metals such as rhodium, cobalt, chromium, ceramics such as silicon carbide or zirconia, or polymers. However, there were disadvantages in terms of abrasion resistance, ceramics in texture, and polymers in durability and sharpness, and no single material could satisfy all requirements. Furthermore, due to the properties of the coating material, these knives also had minute irregularities on the edge of the cutting edge, and if the coating material was hard, it was extremely difficult to sharpen it flat, and the sharpness was at a very low level. . We have a flat cutting edge;
As a result of research into cutting tools with good sharpness, we learned that by coating the base cutting edge with amorphous ceramics to a certain thickness, minute irregularities on the cutting edge can be eliminated and a flat, sharp cutting tool can be obtained. In addition, since the coating ceramic is amorphous, it has a strong bond with the cutting edge of the base material and is hard, so it does not wear or peel off, so there is no need to sharpen it during use. That is, the amorphous ceramic is coated on the cutting edge of the base material as thinly as possible, to a thickness of 1 μm or less, preferably 0.5 μm or less. The amorphous ceramic coats the cutting edge of the base material preferentially over the concave portions of the cutting edge of the base material, thereby flattening the irregularities occurring on the cutting edge of the base material. When the coating layer of amorphous ceramics is made thicker, the coating layer of amorphous ceramics is further crystallized on the cutting edge of the base material, which has been coated from the recessed portion and is once flattened. This is undesirable because minute irregularities on the cutting edge due to the amorphous ceramics occur regardless of the irregularities on the base material cutting edge. Crystallization of amorphous ceramics is less likely to cause unevenness than crystallization of conventionally used crystalline coating materials. Therefore, if the thickness of the amorphous ceramic coating layer is 1 μm or less, there is no need for practical grinding to flatten the minute irregularities on the cutting edge.

The ceramics used as raw materials include zirconium, titanium oxide, titanium carbide, aluminum oxide, other substances commonly used as ceramics in vapor deposition, and hydroxyapatite, and even if these ceramics are crystalline, they are amorphous. It doesn't matter if it is. Particularly, the use of hydroxyapatite is preferable because it has good biocompatibility as a biomaterial, and unlike general ceramics, it is possible to obtain a sharp knife that is smooth against the skin.

As a method for coating the base cutting edge with amorphous ceramics, it is convenient to use commonly used film forming methods such as vacuum evaporation, sputtering, and ion plating. If the coating layer is very thin, such as 0.05 μm, the cutting quality may be good, but the corrosion resistance may not be very good. is good. Substrate cutlery coated with amorphous ceramics can be used not only with materials conventionally used for cutlery such as stainless steel, but also with base materials such as plastic and ceramics. The substrate cutter is loaded as a substrate and the ceramic plate is loaded as a target in each of the above-mentioned devices, and each device is operated in a conventional manner. By adjusting the operating conditions appropriately, for example, the substrate temperature can be kept below 400℃ and the film thickness can be reduced to 1μm.
By making the following adjustments, it is possible to obtain a blade having an amorphous ceramic coating layer of arbitrary density and thickness and a hard, flat cutting edge, which does not need to be sharpened since it will not wear off and peel off. The thickness of the coating layer of the resulting coated cutter can be adjusted by using a conventional film thickness measurement method, and the amorphization of the coating layer can be easily confirmed by infrared spectroscopy and X-ray diffraction, Flatness is confirmed by light reflection.

Function: When amorphous ceramics are coated on a base blade by vacuum deposition, sputtering, ion plating, etc., the amorphous ceramic coats preferentially over the concave portions of the minute irregularities of the base blade material itself. , Coating is applied to flatten the unevenness of the cutting edge. Furthermore, even when excessively coated on a flattened cutting edge, amorphous ceramics are less likely to produce minute irregularities during coating than crystalline coatings conventionally applied to cutlery. For this reason, the cutting edge coated with a thin layer of amorphous ceramics is flat, and since the coating layer is amorphous, it is strongly bonded to the base cutting edge and will not peel off, and is hard, so it can be sharpened like a conventional knife. It's not necessary and the sharpness is good.

The coating material may be ceramic, which is harder or softer than the substrate of the blade, in order to flatten the unevenness of the blade edge. Further, the coating ceramic may be a composite material.

EXAMPLES The present invention will be specifically described below with reference to Examples.

The steel or stainless steel cutlery used as the base material is shaken in a soda bath, washed with tap water, ultrasonically cleaned in distilled water, washed with acetone, dried in isopropanol vapor, and then heated and dried in air. It was used as a substrate.

The target is crystalline zirconium,
Silicon carbide and hydroxyapatite were used.

Hydroxyapatite was prepared by washing a synthetic powder with water and acetone, drying, pressing, immersing the molded product in acetone, and sintering the immersed molded product at 1000 to 1200°C for 3 hours, and used it as a target.

Example 1 Formation of film by sputtering Sputtering device RF-planar magnetron target 100mm diameter sintered hydroxyapatite sputtering gas 4×10 ^-3 Torr (Ar) Substrate Steel blade forming temperature 100℃ Sputtering voltage 400V Operate for 30 minutes under the following conditions. We were able to coat cutlery with a 0.05μm amorphous hydroxyapatite coating. As a result of X-ray diffraction, the coating hydroxyapatite was found to be amorphous with almost no decomposition products of hydroxyapatite observed.

Example 2 A coating film of 0.5 μm of amorphous hydroxyapatite was formed by repeating the same procedure as in Example 1, except that a stainless steel knife was used instead of a steel knife as the substrate and the operation time was changed from 30 minutes to 3 hours. I got a knife that I have. The results of X-ray diffraction of the coating hydroxyapatite revealed the presence of a slight amount of CaO due to decomposition products.

Example 3 Formation of coating by sputtering Sputtering device RF-diode target SiC Sputtering gas 2×10 ^-2 Torr (Ar) Substrate Zirconia blade forming temperature 400℃ Sputtering voltage 1000V 1 hour operation, amorphous SiC, 1 μm coating film Example 4 Sputtering device for film formation by sputtering RF-planar magnetron target Zr Sputtering gas 3×10 ^-4 Torr (Ar+O ₂ ) Substrate Steel blade forming temperature 200℃ Sputtering voltage 500V 1 hour operation, amorphous ZrO ₂ , 0.1μm coating film example 5 Formation of film by sputtering Sputtering device High frequency sputtering target Hydroxyapatite sputtering gas 2×10 ^-4 Torr (Ar) Substrate Stainless steel razor blade forming temperature 300℃ Sputtering voltage 600V 10 minutes operation, amorphous hydroxyapatite,
500 Å Coating Film Example 6 The same operation as in Example 1 was repeated except that the operating time was changed from 10 minutes to 30 seconds to obtain a razor blade having a 10 Å coating film of amorphous hydroxyapatite.

Effects of the Invention When ceramics are deposited on a base cutter by vacuum deposition, sputtering, ion plating, etc., by selecting the base material temperature, an amorphous ceramic film can be easily deposited to a desired film thickness. Since it is amorphous, the unevenness caused by the material of the cutting edge itself is flattened by the vapor-deposited ceramics, and in addition, the bonding force between the coating and the cutting edge is strong, and the coating is hard, so the coating will not peel off.
For this reason, there is no need to sharpen the edge of the blade to make it flat, and it is possible to obtain a sharp knife without sharpening. In addition, the base material for cutlery does not need to be limited to conventionally used cutlery; by adjusting the base material temperature, materials that are not conventionally used for cutlery, such as plastic, can be coated with amorphous ceramics using this method. By doing so, a substance that can be used as a knife was obtained. In particular, razors that use hydroxyapatite as a ceramic and are coated with a thickness of less than 1 μm are corrosion resistant, durable,
Not only does it have improved hardness and sharpness, but hydroxyapatite has good biocompatibility, so it has a smooth texture and does not cause irritation due to razor burn.

Claims (1)

[Scope of Claims] 1. A cutlery using crystalline or amorphous ceramics as a target and forming an amorphous ceramic layer with a thickness of 1 μm or less. 2. The cutlery according to claim 1, wherein the ceramic layer is hydroxyapatite.