JPS6058806A - Edge for razor - 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 The present invention relates to razor blades, and more particularly to razor blades made of ceramic material.

A razor blade usually has a tip radius r of 0.2μ to α5μ.
sharpness is required.

When constructing razor blades from ceramic materials, the particle size of the powder used as raw material is approximately 1μ, so the value of r, which represents sharpness, is smaller than the average particle size of the powder. It becomes. The relationship between the powder diameter and the cutting edge is schematically shown in Figure 1 (A) and (B), and (A
) corresponds to a case where the cutting edge has a small radius and good sharpness), and (B) corresponds to a case where the cutting edge has a large radius and is dull.

As mentioned above, the r of the cutting edge must be α2 to 0.5μ, and the powder used must be α2 to 0.5μ. This value is one order of magnitude lower than the diameter. Therefore, the powder particles themselves are ground by the grinding with the blade. This pattern is shown in figure (A). Therefore, it is necessary to improve the adhesion of a portion of the binder compared to the case where r is large as shown in Figure (B). Therefore, 1 to 3
tnn/cm Ilzn The powder particles are compacted and tightened under such high pressure that they are on the verge of breaking. In this case, in the case of figure (B), the particles are somehow maintained without being lost, but in figure (A), since the adhesion area is small, the strength of the bond part is still insufficient, and particles are likely to be lost. Ru.

Currently, in order to increase sharpness and reduce chipping of the cutting edge, there is no way to achieve this other than by increasing the adhesive strength of the binder under the relative relationship shown in Figure (A).

Two methods are generally possible to increase the adhesive strength of the binder. That is, the first method is to increase the adhesion force by co-dissolution by mixing different types of oxide fine powder, and the second method is to increase the adhesion force by co-dissolution by mixing different types of oxide fine powder. By mixing fine powder, the aim is to form bonds through non-co-solution (through direct sintering). The former is called liquefied bond, and the latter is called direct sintered bond. If it is made into a liquefied bond, the adhesive strength can be increased, but latent strain occurs due to the thermal shrinkage difference f, and brittleness becomes noticeable. On the other hand, it has been found that embrittlement due to latent strain can be avoided if the material is directly sintered into a bond.

Therefore, for current razor blades, this direct sinter bonding method is the only option. In this case, it has already been verified in the field of ceramics that the higher the fineness of the fine powder added for direct sintering, the greater the effect.

However, as the fineness of the powder increases, it becomes difficult to mold it, and it has been difficult to put it into practical use due to the lack of suitable molding means that can be economically mass-produced.

The present invention solves the above-mentioned problems and provides a ceramic razor blade that has strong direct sintered bonding, good sharpness, and is resistant to chipping of the cutting edge and is highly durable.

In the present invention, the use of a sol is applied as the ultimate in pulverization. That is, by adding a zirconia sol to the base zirconia powder, a state where direct sintering is most likely to occur is created.

As a result, it is possible to reduce the thickness of the part of the binder shown in Figure 1 (A) and increase the radius of the tip of the cutting edge, making it possible to give maximum strength to this thin bonded part. It is.

As a molding method for this material (zirconia powder/zirconia sol-based raw material), one of the inventors invented and applied for a patent for the fluid compression molding method in Japanese Patent Application No. 136845/1984, and the injection filtration compression molding method related to a subsequent application. By applying the invention disclosed in 1996, this difficulty was overcome and success was achieved.

That is, as shown in FIG. 2, the calculated amount of zirconia powder/zirconia sol type molding interaction is put into the mold 2,
The compression column 3 is lowered from the top at a compression speed set in advance in terms of fluid flow so that the molding material 1 can exhibit liquid properties once it is in a fluid state, and is shaped into a thin plate. During molding, excess molding material is inserted through the gap between the mold and the punch and discharged out of the mold. After the modeling is completed, the gap between the mold and the pestle is closed, and it is placed under conditions that allow it to exhibit its solid properties.
The shaped body is consolidated at the descending speed of the compression column set rheologically, and shape retention is performed. The descending speed of the punch during compaction is 1/10 or less of the speed during molding.

Note that if a small amount of liquid comes out during consolidation, there is no problem because it oozes out from the closed lid, but depending on the composition of the molding material, the convex body may contain a large amount of moisture, and in this case, the third As shown in the figure, a male filter plate that is in contact with the molded body and allows only water to pass through is attached to the bottom of the mold, and water generated during consolidation is discharged out of the mold through the filter plate. As the filter plate 4, a porous sintered ceramic plate or the like is used.

The above has described the zirconia powder/zirconia sol type molding material, but it has also been verified that an alumina powder/aluminum sol type molding material can also be formed into a thin plate as a razor material by the above method.

Since the molded body has sufficient shape retention, it can be removed from the mold, and the silica thus obtained is fired to make a razor barley. Sharpen the blade using an H-nim to create a single-sided or double-sided polished blade.

Next, a coating is applied to the cutting edge or the vicinity of the cutting edge, or both of the blades, to form a product.

The coating is, for example, a fluororesin coating.

For this coating, a wet mixture of oil-in-water emulsions of polytetrafluoroethylene and hydrogen methylpolysiloxane disclosed in JP-A-58-37094 entitled "Composition for coating cutlery" is preferably used.

According to the present invention, high-quality ceramic razor blades with good sharpness and excellent durability can be mass-produced.
This is extremely beneficial for consumers.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example Zirconia powder (ZrO2 purity 99.0%, average particle size 1
μ) Add zirconia acrylate hydrosyl to 100 parts by weight in an appropriate amount within the range of 15 to 45 parts by weight CMC, P
Appropriate amounts of VA and oil/oil emulsion (trade name: Maxelon) were added, the soil was prepared, and the starting material was fluidized and compacted under vacuum to prevent degassing and outside air from entering, using the equipment shown in Figure 2. .

The silica base obtained by demolding was fired at 1600° C. for 2 hours to obtain a razor blade base having a thickness of α5 mm.

This 0.5 mm thin plate was subjected to a sharpening process in the following order.

1. Diamond grindstone #180 2. Same abrasive grain #500 3. Same abrasive grain + 3000 pieces Diamond paste 05μ The sharpness of the razor blade obtained in this polishing process was measured. As shown in Fig. 4, the measuring device consists of a nylon thread 6 stretched between pulleys 5 and 5 provided at a spacing of 20 cm, a weight 7 of 100 gr attached to each end of the thread, and a razor blade 8 attached to the thread. It is lowered at a constant speed by a motor, and the position where the thread is cut is displayed as the distance amIn from the thread level line. This distance is read on measure 9. For comparison,
A commercially available stainless steel razor blade was also measured. The measurements were carried out on 10 sheets each, and the average value of the 7C0 results are shown in Table 1 below.

Table 1 The results demonstrate that the razor blades formed with the sol dispersion have the same sharpness as commercially available stainless steel razor blades.

We also conducted a durability test on the blade. The test was conducted using a device similar to that shown in FIG. 4, and the number of cuts until the nylon material could no longer be cut was determined. As a nylon type, 01m
A diameter of m was used. The results are shown in Table 2 below.

As can be seen from Table 2, the blade is formed by a sol dispersion system, and approximately 2
It has been shown to be more than twice as durable.

Table 2

[Brief explanation of the drawing]

Figure 1 is a diagram schematically showing the relationship between the cutting edge of a razor blade and powder particles, Figures 2 and 3 are longitudinal cross-sectional views of a fluid compaction device, and Figure 4 is a measurement of the sharpness of the blade. FIG. 2 is a schematic structural diagram of the device. 1... Molding raw material, 2... Molding mold. 8... Compressibility, 4r... Bow filter plate. 5... Pulley, 6... Nylon type. 7... Weight, 8... Razor blade. Figure 1 (A) (B) Figure 2 Figure 3 Procedural amendment October 19, 1980 Director of the Japan Patent Office Kazuo Wakasugi 1, Indication of the case 1982 Patent Application No. 166950 2 Title of the invention Razor's Blade 3 Relationship with the case of the person making the amendment Patent applicant address 1-30-13 Ume, Kiyamahonmachi, Sendai City, Miyagi Prefecture
Name: 6 Address: 7-5-5, Ginza, Chuo-ku, Tokyo Name (i195): Shisei Doyama Co., Ltd. Representative: Kichibei Yamamoto Principal Agent: 156 Telephone: Tokyo (+03) 322-4850 Address: 3-27-27 Matsubara, Setagaya-ku, Tokyo The number of inventions will not increase due to the amendment7. Explanation j column & contents of amendment (1) As per appended claims (2) Detailed explanation of the invention 1, Specification letter page 2 The second line from the bottom, “Adherence of part of binder” should be changed as follows: Correct to. ``Since the adhesive area occupied by a part of the binder is reduced,
Adhesive strength (adhesiveness) j 2, same page 2, bottom line to page 3, line 5, “As a result, damage may occur.” is corrected as follows. . ``Therefore, the powder particles (fine particles) of 1 to 3 ton/cm'' are compacted and tightened under such high pressure that they are on the verge of breaking. In this case, if we look at the ceramic body after firing (
In the case of figure B), the particles of the fleas are somehow kept intact and the ceramic strength is maintained because there is a large bonding area in a part of the binder, but in figure (A), the bonding area in a part of the binder is small. , (B) In order to generate the same strength as in the case of the figure, it is necessary to increase the strength of the bond portion. ” & Page 3 of the specification, line 13, “co-solution” is amended to “co-solution”. Honma, page 3, line 15, correct "fine powder" to "ultrafine powder". S Same, page 3, line 16, amend "co-solution" to "co-solution." 6 Same page, page 3, line 16, amend "bond formation" to "bond formation." 7, same page 3. In the bottom line, "latent strain" is corrected to "potential mechanical strain."& Same car 4th line 5th line "Fine powder" is corrected to "Ultrafine powder". α Same page 5, line 10, ``difficulty'' is corrected to ``difficulties that occur during molding.'' 1α Specification, page 6, lines 6 to 7, “Depending on the composition of the molding material, the shaped object may contain moisture” is corrected as follows. ``Depending on the composition of the molding material, the molded object may contain (-T) moisture.'' 11, page 7, second line from the bottom, ``Zirconia acrylate J is corrected to ``zirconia acetate''. 12, page 8, page 14. Correct the line "Sharpness of razor blade" to "Sharpness of razor blade". 13, same page 9, Table 1, five examples Correct the column "49" for the cutting value of the blade to r 490 J. Attachment 2, Claim 1, Shape retention is performed by reconsolidating the zirconia powder/zirconia sol molding material or the alumina powder/alumina sol molding material, followed by demolding, firing, and cutting. 2. A razor blade according to claim 1, in which the cutting blade is a single-sided polished blade or a double-sided polished blade. & A patent claim that has a coating on and/or near the cutting blade. The razor blade described in the range M2.

Claims (1)

[Scope of Claims] 1. Using a zirconia powder/zirconia sol molding material or an alumina powder/alumina sol molding material, the material is once placed in a fluidized state to exhibit liquid properties. , a filter plate that is shaped into a razor blade shape, then placed under a condition where it can exhibit solid properties by confining the shaped body under a condition where it cannot flow, and in advance drains liquid into the mold outside the mold. A razor blade that is formed by retaining its shape by compacting it again with or without the provision of a mold, followed by demolding, firing, and a cutting edge. 2. The razor blade according to claim 1, wherein the cutting edge is a single-sided polished blade or a double-sided polished blade. & “Jl” of the razor described in claim 2, which has a coating on and/or near the cutting blade.