Blade and method for manufacturing blade

Abstract

To provide a blade with high durability that can be used for a long time.SOLUTION: A blade 1 includes a substrate 100 formed of a material containing Fe, and a hard-coat layer 120 formed on the substrate 100. The hard-coat layer 120 includes DLC layers 121 and metal layers 122 alternately arranged in the stacking direction. The DLC layer 121 is formed of a material containing DLC, and the metal layer 122 is formed of a material containing a metal or semimetal. The hard-coat layer 120 includes two or more DLC layers 121.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One aspect of the present invention relates to a blade body and a method for manufacturing the blade body. [Background technology]

[0002] Conventionally, there has been a technology for coating razor blades with amorphous diamond, as described in Patent Document 1. This blade has a structure in which an amorphous diamond film is applied to a substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 9-512447 Summary of the Invention [Problem to be solved by the invention]

[0004] Of the 17 Sustainable Development Goals (SDGs) adopted at the United Nations Summit, Goal 12, "Responsible Consumption and Production," calls for ensuring sustainable production and consumption patterns, and calls for a significant reduction in waste generation. For example, Goal 12-5 calls for a significant reduction in waste generation by 2030 through prevention, reduction, recycling, and reuse. Under these circumstances, there is also a call for a reduction in waste generation in the area of ​​blades used in cutting tools, including razors.

[0005] The inventors have been working on improving blades used in razors, etc., with the goal of achieving the prevention of waste generation, etc., as set forth in Goal 12-5 of the SGDs. One of the goals of the present invention is to provide a blade with a configuration different from that described in Patent Document 1, which has excellent durability and can be used for a long period of time. [Means for solving the problem]

[0006] One aspect of the present invention is a substrate formed of a material containing Fe; a hard coat layer formed on the substrate, the hard coat layer includes DLC layers and metal layers alternately arranged in a stacking direction, the DLC layer is formed of a material containing DLC, the metal layer is formed of a material containing a metal or a semi-metal; The hard coat layer includes two or more DLC layers. It is a blade.

[0007] According to the inventors' research, the blade body with the amorphous diamond coating described in Patent Document 1 has a relatively high hardness, but high hardness films generate high internal stress, and increasing the film thickness can lead to breakage. When the amorphous diamond coating on the surface of the blade body is broken, the PTFE film formed on the surface of the amorphous diamond coating also peels off, resulting in a poor shaving experience. Furthermore, when body hair such as whiskers is cut at a location where the film is broken, the breakage in that location progresses, further worsening the shaving experience. Furthermore, the film formation method for achieving a dense amorphous diamond film that is high in hardness and free of droplets has the problem of slow film formation speed and low productivity.

[0008] The blade of the present invention has a hard coat layer including diamond-like carbon (DLC) layers and metal layers alternately arranged in the stacking direction. This allows for a thinner DLC layer than a hard coat layer made entirely of DLC, reducing the internal stress of the DLC layer within the hard coat layer and making it less susceptible to breakage. Furthermore, because the metal layer is deposited faster than the DLC layer, the deposition time required to achieve the desired hard coat thickness can be shortened, thereby increasing blade productivity.

[0009] From the customer's perspective, this means that razors and the like that are highly durable and can be used for a long period of time can be provided. Furthermore, improved productivity means that razors and the like can be provided at lower prices.

[0010] Furthermore, from the perspective of the SDGs, providing durable razors and other products that can be used for a long time will reduce waste generation and contribute to creating a sustainable and better world.

[0011] In the above blade body, preferably, At least one of the two or more DLC layers has an SP3 structure of 40% or more.

[0012] The blade body can be configured to have a DLC layer with sufficient hardness for use as a blade body.

[0013] In the above blade, the hard coat layer preferably has a thickness of 5 nm to 1000 nm, more preferably 10 nm to 500 nm, and even more preferably 15 nm to 400 nm.

[0014] The blade body described above employs a structure including DLC ​​layers and metal layers arranged alternately in the stacking direction, thereby achieving a well-balanced structure that provides a satisfactory shaving feel while also being excellent in durability and productivity.

[0015] In the above blade body, preferably, The DLC layer and the metal layer each have a thickness of 1 nm to 150 nm, more preferably 3 nm to 100 nm, and even more preferably 5 nm to 80 nm.

[0016] In the above blade body, preferably, Further provided is a fluororesin layer formed of a fluororesin on the hard coat layer, The DLC layer is disposed so as to be in contact with the fluororesin layer.

[0017] According to the above blade, the DLC layer and the fluororesin layer are adjacent to each other, and the blade has high cutting performance and durability.

[0018] In the above blade body, preferably, an adhesion layer formed of a material containing a metal or a metalloid between the substrate and the hard coat layer; the hard coat layer is formed by laminating a first DLC layer, a first metal layer, a second DLC layer, a second metal layer, and a third DLC layer in this order; The first metal layer and the second metal layer are formed of a material containing Cr, CrN, or CrC.

[0019] One aspect of the present invention is forming a first DLC layer made of a material containing DLC ​​on a substrate made of a material containing Fe; forming a metal layer made of a material containing a metal or a semi-metal on the first DLC layer; forming a second DLC layer made of a material containing DLC ​​on the metal layer; This is a method for manufacturing a blade body. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a cross-sectional view of a blade body according to an embodiment. [Figure 2] FIG. 2 is a flowchart showing a method for manufacturing a blade body according to an embodiment. [Figure 3] FIG. 3 is a table showing the results of the cutting performance comparison experiment. [Figure 4] FIG. 4 is a table showing the results of the cutting performance comparison experiment. [Figure 5] FIG. 5 is a diagram showing a laminated structure at the cutting edge of the blade body according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] The blade of the present invention is primarily used in razors, but can also be applied to blades other than razors. The blade of the present invention will be specifically described below with reference to the drawings. However, the embodiment described below is merely an example of the present invention and is not intended to limit the technical scope of the present invention. In each drawing, identical components are denoted by the same reference numerals, and their description may be omitted. In this specification, when describing the layered structure of the blade, for convenience, the direction in which layers are stacked relative to the substrate will be described as the upper side. Furthermore, in this specification, each layer of the components will be referred to as a "film," and the formation of a layer will be referred to as "film formation."

[0022] <Blade configuration> Fig. 1 is a diagram showing an example of the configuration of a blade body 1 according to this embodiment. As shown in Fig. 1, the blade body 1 is composed of a substrate 100, an adhesion layer 110, a hard coat layer 120, and a fluororesin layer 130. Fig. 1 shows a cross section of the blade body 1 in a plate-like laminated state as a specific example of the laminated structure of the blade body 1, but the laminated structure at the cutting edge may be as shown in Fig. 5, for example.

[0023] <Base material 100> The substrate 100 is a metal that will be the material of the blade 1 before coating is applied, and is made of a material containing Fe. The substrate 100 is made of, for example, stainless steel containing Fe (iron), C (carbon), and Cr (chromium). For example, the substrate 100 contains Fe as the main component, 10.5% or more of Cr, and 1.2% or less of C.

[0024] <Adhesion layer 110> The adhesion layer 110 is formed by laminating it on the substrate 100. The adhesion layer 110 is disposed between the substrate 100 and the DLC layer 121, which is the bottom layer of the hard coat layer 120.

[0025] The adhesion layer 110 is formed of a material containing a metal or a semi-metal. The metal or semi-metal forming the adhesion layer 110 includes at least one of Cr (chromium), Ti (titanium), W (tungsten), Si (silicon), Nb (niobium), B (boron), Zr (zirconium), Pt (platinum), Al (aluminum), Ni (nickel), Cu (copper), Au (gold), Ag (silver), Co (cobalt), Zn (zinc), Sn (tin), Hf (hafnium), Ga (gallium), Ge (germanium), In (indium), Pd (palladium), Ru (ruthenium), Ir (iridium), and Rh (rhodium).

[0026] The material for forming the adhesion layer 110 is preferably any one of Cr, Ti, W, Si, Nb, B, Zr, Pt, Al, Ni, Cu, Au, Ag, Co, and Zn, and more preferably any one of Cr, Ti, W, Si, Nb, B, Zr, and Pt.

[0027] Specifically, nitrides, carbides, or oxides of these metals or semimetals can be used as the material for forming the adhesion layer 110. The adhesion layer 110 may be made of, for example, Cr, Ti, TiN (titanium nitride), TiC (titanium carbide), CrN (chromium nitride), or CrC (chromium carbide).

[0028] The materials forming the adhesion layer 110 and the metal layer 122 may be the same or different, but are preferably the same material, more preferably Cr or Ti.

[0029] The adhesion layer 110 is formed by, for example, sputtering.

[0030] The thickness of the adhesive layer 110 is 5 nm or more and 200 nm or less, preferably 10 nm or more and 100 nm or less, and more preferably 20 nm or more and 50 nm or less.

[0031] <Hard coat layer 120> As shown in FIG. 1, the hard coat layer 120 is formed by alternately laminating DLC layers 121, metal layers 122, DLC layers 121, metal layers 122, and DLC layers 121 in the stacking direction. As shown in FIG. 1, it is preferable that the lowermost layer and the uppermost layer of the hard coat layer 120 are DLC layers 121.

[0032] <DLC layer 121> The DLC layer 121 is formed of DLC (Diamond-Like Carbon). The DLC layer 121 may be composed of a stack of a plurality of DLC layers.

[0033] In at least one of the plurality of DLC layers 121, the proportion of the SP3 structure in the DLC constituting the DLC layer 121 is preferably 40% or more, more preferably 60% or more. In the other layers of the DLC layer 121, the proportion of the SP3 structure in the DLC constituting them may be less than 40%, but is preferably 40% or more, more preferably 60% or more.

[0034] The DLC layer 121 is formed, for example, by a filtered cathode arc method. According to this filtered cathode arc method, a DLC layer with an SP3 structure of generally 40% or more can be formed.

[0035] The film thickness of the DLC layer 121 is 1 nm or more and 150 nm or less, preferably 3 nm or more and 100 nm or less, more preferably 5 nm or more and 80 nm or less.

[0036] <Metal layer 122> The metal layer 122 is formed of a material containing a metal or a semi-metal, and the metal or semi-metal forming the metal layer 122 includes at least one of Cr (chromium), Ti (titanium), W (tungsten), Si (silicon), Nb (niobium), B (boron), Zr (zirconium), Pt (platinum), Al (aluminum), Ni (nickel), Cu (copper), Au (gold), Ag (silver), Co (cobalt), Zn (zinc), Sn (tin), Hf (hafnium), Ga (gallium), Ge (germanium), In (indium), Pd (palladium), Ru (ruthenium), Ir (iridium), and Rh (rhodium).

[0037] The material for forming the metal layer 122 is preferably any one of Cr, Ti, W, Si, Nb, B, Zr, Pt, Al, Ni, Cu, Au, Ag, Co, and Zn, and more preferably any one of Cr, Ti, W, Si, Nb, B, Zr, and Pt.

[0038] Specifically, nitrides, carbides, or oxides of these metals or semimetals can be used as materials for forming the metal layer 122. The metal layer 122 may be made of, for example, Cr, Ti, TiN (titanium nitride), TiC (titanium carbide), CrN (chromium nitride), or CrC (chromium carbide). Note that the metal layer 122 may be formed by stacking multiple metal layers made of different materials.

[0039] The metal layer 122 is formed by, for example, magnetron sputtering. The deposition rate of the metal layer 122 is faster than the deposition rate of the DLC layer 121.

[0040] The thickness of the metal layer 122 is set to 1 nm or more and 150 nm or less, preferably 3 nm or more and 100 nm or less, and more preferably 5 nm or more and 80 nm or less.

[0041] The total film thickness of the hard coat layer 120 is 5 nm or more and 1000 nm or less, preferably 10 nm or more and 500 nm or less, and more preferably 15 nm or more and 400 nm or less.

[0042] <Fluororesin layer 130> The fluororesin layer 130 is a layer made of a material containing fluorine and coating the surface of the blade body 1. The fluororesin layer 130 is made of, for example, PTFE (polytetrafluoroethylene). Existing technology may be used to form the fluororesin layer 130.

[0043] <Method of manufacturing blade 1> Next, a specific example of a method for manufacturing the blade body 1 will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the method for manufacturing the blade body 1 of this embodiment.

[0044] As shown in FIG. 2, first, the prepared substrate 100 is cleaned with an Ar (argon) ion beam (S1).

[0045] Next, a Cr or Ti film of the adhesion layer 110 is formed on the substrate 100 by magnetron sputtering (S2).

[0046] Next, the DLC of the DLC layer 121 is formed on the adhesion layer 110 by cathodic arc (S3).

[0047] Next, a metal layer 122 of Cr or Ti is formed on the DLC layer 121 by magnetron sputtering (S4).

[0048] Next, the DLC of the DLC layer 121 is formed on the metal layer 122 by cathodic arc (S5).

[0049] Through the above steps, the DLC layer 121, the metal layer 122, and the hard coat layer 120 having the DLC layer 121 are formed. If it is necessary to further form the DLC layer 121 and the metal layer 122 that form the hard coat layer 120 (N in S6), the above steps S4 and S5 are repeated. When the formation of the hard coat layer 120 is completed (Y in S6), the fluororesin layer 130 is formed and coated on the DLC layer 121, which is the top layer of the hard coat layer 120 (S7).

[0050] The blade body 1 of this embodiment can be manufactured by the above-described method. Note that the method described here is merely an example, and other methods may be employed. The cathodic arc as a filtered cathodic arc method and magnetron sputtering as a sputtering method used in each film formation process are merely examples, and other methods may be employed.

[0051] <Cutting performance comparison of blade 1> As will be described below, the blade body 1 of this embodiment has higher cutting performance than the configurations given as comparative examples.

[0052] <Experiment 1> 3 is a table showing the results of the first cutting performance comparison experiment. In this experiment, the hard coat layer was configured as follows: (1) a configuration using only Cr (comparative example), (2) a configuration using only DLC (comparative example), and (3) a configuration using the laminated DLC of the embodiment. That is, in the configuration using only Cr (1) and the configuration using only DLC (2), the configuration of the hard coat layer 120 in the configuration of the embodiment is different from the configuration of the embodiment.

[0053] (1) In the configuration using only Cr, Cr was used for the adhesion layer and the hard coat layer, and the thickness of the coating layer including the adhesion layer and the hard coat layer was set to 50 nm.

[0054] (2) In the DLC-only structure, Cr was used as a 20 nm adhesion layer and DLC was used as a 105 nm hard coat layer, and the coating layer including the adhesion layer and hard coat layer was 125 nm thick. Note that the hardest part of this DLC layer, with an SP3 of 40% or more, was located approximately 90 nm from the surface.

[0055] (3) In the embodiment using the laminated DLC, Cr was used as the adhesion layer of 20 nm, and a 15 nm DLC was further formed on top of the 15 nm Cr laminated layer as the hard coat layer. The thickness of the coating layer including the adhesion layer and the hard coat layer was 125 nm.

[0056] In the experiment, the blades having the hard coating layer were used to cut wool felt, and the load required for the 10th cut (Cutting Test 1), at which the effect of the surface coating on cutting performance stabilized, and the load required to cut the wool felt again after a predetermined durability test (Cutting Test 2) were measured. In other words, the experiment confirmed whether the load required for cutting increases and cutting performance deteriorates when wool felt is repeatedly cut.

[0057] The experimental results are shown in Figure 3. The load required to cut the wool felt again after the durability test (cutting test 2) was 4.32 N for the configuration using the laminated DLC of the embodiment, which was lower than 5.14 N for the configuration using only Cr and 5.70 N for the configuration using only DLC. Furthermore, in this experiment, in the configuration using only DLC as in (2), peeling was sometimes observed in part of the hard coat layer after the durability test. Thus, it was confirmed that the configuration using the laminated DLC of the embodiment as the hard coat layer has higher durability than the configuration using only Cr or only DLC as the hard coat layer.

[0058] <Experiment 2> Fig. 4 is a table showing the results of the second cutting performance comparison experiment. In this experiment, the blade body 1 was used, which was constructed using the laminated DLC of the embodiment, but the construction of the hard coat layer 120 was different. That is, the construction of the hard coat layer 120 was as follows: (1) A first structure consisting of three layers: a 15 nm DLC layer, a 15 nm Cr layer (metal layer), and a 15 nm DLC layer; and (2) A second structure consisting of four layers: a 15 nm DLC layer, a 7.5 nm Cr layer (metal layer), a 15 nm DLC layer, and a 7.5 nm Cr layer (metal layer); In both configurations, the adhesion layer was made of 20 nm Cr, and the thickness of the coating layer including the adhesion layer and hard coat layer was 65 nm.

[0059] The experiment was conducted in the same manner as in Experiment 1 above. The experimental results are shown in FIG. 4, and the load required to cut the wool felt again after the durability test (cutting test 2) was 6.10 N for the first configuration and 7.55 N for the second configuration. That is, it was confirmed that the first configuration in which the outermost surface (top layer) of the hard coat layer 120 was made of DLC had higher durability than the second configuration in which the outermost surface (top layer) of the hard coat layer 120 was made of Cr. That is, it was found that a configuration in which the outermost surface (top layer) of the hard coat layer 120 was made of a DLC layer provided higher durability.

[0060] Comparing Cutting Test 1 and Cutting Test 2 in Experiment 1 and Experiment 2, the cutting load in Experiment 1 was generally lower. This was due to the difference in the shape of the blade used in Experiment 1 and the shape of the blade used in Experiment 2. In other words, it is not appropriate to compare the cutting performance between Experiment 1 and Experiment 2.

[0061] <Modification> The blade body 1 of the above embodiment can employ the following modified examples. Note that the modified examples described below should not be interpreted as limiting the present invention, but are described as specific examples.

[0062] The number of DLC layers 121 and metal layers 122 in the hard coat layer 120 constituting the blade body 1 may be changed as desired. However, for example, a configuration having three DLC layers 121 and two metal layers 122, or a configuration having four DLC layers 121 and three metal layers 122, is preferable because the film formation configuration does not become too complicated.

[0063] Blade body 1 can be used as a blade for T-type razors, as well as for L-type razors, nail clippers, scissors, kitchen knives, cutters, microtomes, medical scalpel blades, or specialized industrial blades. Blade body 1 is particularly suitable for use as a blade for razors that are replaced periodically. Blade body 1 is suitable for thin blades with a thickness of 1.0 mm or less, preferably 0.5 mm or less.

[0064] <Features of the embodiment> The blade body of one embodiment described above by exemplifying the embodiment and the modified examples has the following features.

[0065] The blade body 1 of this embodiment includes a substrate 100 made of a material containing Fe and a hard coat layer 120 formed on the substrate 100. The hard coat layer 120 includes DLC layers 121 and metal layers 122 alternately arranged in the stacking direction. The DLC layers 121 are formed of a material containing DLC, and the metal layers 122 are formed of a material containing metal or semimetal. The hard coat layer 120 includes two or more DLC layers 121. A blade body 1 with this configuration can have thinner DLC layers 121 than a hard coat layer formed entirely of DLC. This configuration allows for a thinner DLC layer 121 for each hard coat layer 120, reducing the stress generated within the DLC layer 121 and making it less susceptible to breakage. Furthermore, the proportion of the DLC layer, which requires a long film formation time, can be reduced within the desired film thickness, thereby increasing the speed at which the hard coat layer 120 is completed, i.e., the film formation rate, and thus improving productivity.

[0066] Furthermore, at least one of the two or more DLC layers 121 of the blade 1 has an SP3 structure of 40% or more, so that the blade 1 can be configured to have a DLC layer with sufficient hardness for use as a blade.

[0067] The blade 1 has a hard coat layer 120 having a thickness of 5 nm to 1000 nm, preferably 10 nm to 500 nm, and more preferably 15 nm to 400 nm. This blade 1 employs a configuration including DLC ​​layers 121 and metal layers 122 alternately arranged in the stacking direction, providing a well-balanced configuration that offers excellent durability and productivity while still providing a satisfactory shaving feel.

[0068] In the blade body 1, the DLC layer 121 and the metal layer 122 each have a thickness of 1 nm to 150 nm, preferably 3 nm to 100 nm, and more preferably 5 nm to 80 nm.

[0069] The blade body 1 further includes a fluororesin layer 130 formed of a fluororesin on the hard coat layer 120, and the DLC layer 121 is disposed so as to be in contact with the fluororesin layer 130. With this type of blade body 1, the DLC layer 121 and the fluororesin layer 130 are adjacent to each other, which provides high cutting performance and durability.

[0070] The blade 1 further includes an adhesion layer 110 formed of a material containing a metal or a semi-metal between the substrate 100 and the hard coat layer 120. The hard coat layer 120 is formed by laminating a first DLC layer 121, a first metal layer 122, a second DLC layer 121, a second metal layer 122, and a third DLC layer 121 in this order. The first metal layer 122 and the second metal layer 122 are formed of a material containing Cr, CrN, or CrC.

[0071] On the other hand, the manufacturing method of the blade body 1 in the embodiment is as follows: (1) Step (S3) of forming a first DLC layer 121 made of a material containing DLC ​​on a substrate 100 made of a material containing Fe; (2) Step (S4) of forming a metal layer 122 made of a material containing a metal or a semi-metal on the first DLC layer 121; (3) A step (S5) of forming a second DLC layer 121 made of a material containing DLC ​​on the metal layer 122. [Explanation of symbols]

[0072] 1...Blade body 100...Base material 110...adhesion layer 120...Hard coat layer 121…DLC layer 122...Metal layer 130...Fluororesin layer

Claims

1. a substrate formed of a material containing Fe; a hard coat layer formed on the substrate, the hard coat layer includes DLC layers and metal layers alternately arranged in a stacking direction, the DLC layer is formed of a material containing DLC, the metal layer is formed of a material containing a metal or a semi-metal; The hard coat layer includes two or more DLC layers. Blade body.

2. At least one of the two or more DLC layers has an SP3 structure of 40% or more. The blade according to claim 1 .

3. The hard coat layer has a thickness of 5 nm or more and 1000 nm or less. The blade according to claim 1 .

4. The hard coat layer has a thickness of 10 nm or more and 500 nm or less. The blade according to claim 1 .

5. Each of the DLC layer and the metal layer is 1 nm or more and 150 nm or less. The blade according to claim 1 .

6. The DLC layer and the metal layer each have a thickness of 3 nm or more and 100 nm or less. The blade according to claim 1 .

7. Further provided is a fluororesin layer formed of a fluororesin on the hard coat layer, The DLC layer is disposed so as to be in contact with the fluororesin layer. The blade according to claim 1 .

8. an adhesion layer formed of a material containing a metal or a metalloid between the substrate and the hard coat layer; the hard coat layer is formed by laminating a first DLC layer, a first metal layer, a second DLC layer, a second metal layer, and a third DLC layer in this order; the first metal layer and the second metal layer are formed of a material containing Cr, CrN, or CrC; The blade according to claim 7.

9. forming a first DLC layer made of a material containing DLC ​​on a substrate made of a material containing Fe; forming a metal layer made of a material containing a metal or a metalloid on the first DLC layer; forming a second DLC layer formed of a material including DLC ​​on the metal layer; Manufacturing method of blade body.

Images