Blade body and manufacturing method thereof

Abstract

A blade body (1) has a base material (100) formed of a material containing Fe and a hard coating layer (120) formed on the base material (100). The hard coating layer (120) includes DLC layers (121) and metal layers (122) alternately arranged in a 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 semi-metal. The hard coating layer (120) includes two or more DLC layers (121).

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] Previously, there was a technique for applying an amorphous diamond coating to the blade of a razor, as described in Patent Document 1. In this blade, a structure is employed in which an amorphous diamond film is applied to a substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. 9-512447 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Among the 17 Sustainable Development Goals (SDGs) adopted at the UN summit, Goal 12, "Responsible Production and Consumption," proposes ensuring sustainable production and consumption patterns and calls for a significant reduction in waste generation. For example, Goal 12-5 sets the goal of significantly reducing waste generation by 2030 through the prevention, reduction, recycling, and reuse of waste. Against this backdrop, the reduction of waste generation is also required in the field of blades, including those used in razors.

[0008] The inventors have been working to improve blades for use in razors and similar devices, with the goal of preventing waste generation as proposed in SDGs 12-5. This invention constructs a blade with a structure different from that described in Patent Document 1, one of its objectives being to achieve a structure with excellent durability for long-term use.

[0009] Solution for solving the problem

[0010] One aspect of the present invention is a blade, wherein the blade comprises:

[0011] A substrate formed of a material containing Fe; and

[0012] A hard coating formed on the substrate,

[0013] The hard coating comprises DLC layers and metal layers alternately arranged in the stacking direction.

[0014] The DLC layer is formed of a material containing DLC.

[0015] The metal layer is formed of a material comprising metals or semi-metals.

[0016] The hard coating comprises two or more of the DLC layers.

[0017] According to the inventors' research, while the blade with an amorphous diamond coating described in Patent Document 1 has relatively high hardness, the high hardness of the film generates high internal stress, sometimes leading to damage due to increased film thickness. If the amorphous diamond coating on the surface of the blade is damaged, the PTFE film formed on the surface of the amorphous diamond coating will also peel off, thus worsening the shaving experience. Furthermore, if body hair such as beards is cut at the damaged area, the damage will further extend, resulting in an even worse shaving experience. Moreover, the film-forming method for achieving a dense, droplet-free amorphous diamond film with high hardness suffers from slow film-forming speed and low productivity.

[0018] The blade body of the present invention employs a structure comprising alternating DLC ​​(Diamond-Like Carbon) layers and metal layers in the hard coating. Compared to a structure where the entire hard coating is formed of DLC, the thickness of each DLC layer can be reduced, and a structure less prone to breakage can be constructed by reducing the internal stress of the DLC layer in the hard coating. Furthermore, since the metal layer forms a film faster than the DLC layer, the film formation time required to achieve the desired hard coating thickness can be shortened, thereby improving the productivity of the blade body.

[0019] In other words, from the customer's perspective, we can provide razors that are highly durable and can be used for a long time. Furthermore, by increasing productivity, we can provide razors at lower prices.

[0020] Furthermore, from the perspective of the SDGs, by providing long-lasting, durable razors and the like, we can curb waste generation and contribute to creating a sustainable and better world.

[0021] In the aforementioned blade body, preferably, at least one of the two or more DLC layers has an SP3 structure of 40% or more.

[0022] Based on the aforementioned blade body, it is possible to construct a structure with a DLC layer having sufficient hardness to be used as a blade body.

[0023] In the aforementioned blade body, it is preferable to set the hard coating to 5nm or more and 1000nm or less, more preferably 10nm or more and 500nm or less, and even more preferably 15nm or more and 400nm or less.

[0024] Based on the aforementioned blade body, a structure comprising alternating DLC ​​layers and metal layers in the stacking direction can be adopted, resulting in a well-balanced structure that provides a satisfying shaving experience while maintaining excellent durability and productivity.

[0025] In the aforementioned blade body, it is preferable that the DLC layer and the metal layer are respectively set to 1nm or more and 150nm or less, more preferably 3nm or more and 100nm or less, and even more preferably 5nm or more and 80nm or less.

[0026] In the aforementioned blade body, it is preferable that the hard coating layer also includes a fluoropolymer layer formed of fluoropolymer, and the DLC layer is configured to contact the fluoropolymer layer.

[0027] Based on the aforementioned blade body, a structure is formed in which the DLC layer and the fluoropolymer layer are adjacent, which can be configured into a structure with high cutting performance and durability.

[0028] In the aforementioned blade body, it is preferable that an adhesive layer formed of a material containing metal or semi-metal is further provided between the substrate and the hard coating layer, the hard coating layer being formed by stacking in the order of a first DLC layer, a first metal layer, a second DLC layer, a second metal layer and a third DLC layer, the first metal layer and the second metal layer being formed of a material containing Cr, CrN or CrC.

[0029] One aspect of the present invention is a method for manufacturing a blade body, wherein the method comprises the following steps: forming a first DLC layer made of a material containing DLC ​​on a substrate formed of a material containing Fe; forming a metal layer made of a material containing metal or semi-metal on the first DLC layer; and forming a second DLC layer made of a material containing DLC ​​on the metal layer. Attached Figure Description

[0030] Figure 1 This is a cross-sectional view of the blade body in the embodiment.

[0031] Figure 2 This is a flowchart illustrating the manufacturing method of the blade body according to the implementation method.

[0032] Figure 3 This is a table showing the results of a comparative experiment on cutting performance.

[0033] Figure 4 This is a table showing the results of a comparative experiment on cutting performance.

[0034] Figure 5 This is a diagram showing the layered structure at the blade edge of the blade in the embodiment. Detailed Implementation

[0035] The blade of the present invention is primarily used in razors, but can also be used as a blade for other purposes. Hereinafter, the blade of the present invention will be specifically described with reference to the accompanying drawings. However, the embodiments described below are merely examples of the present invention and are not intended to limit the scope of the invention. Furthermore, in the accompanying drawings, the same reference numerals are used to denote the same constituent elements, and their descriptions are sometimes omitted. In this specification, when describing the layered structure of the blade, for ease of explanation, the direction in which the layers are stacked relative to the substrate is described as upward. Additionally, in this specification, each layer of the constituent elements is sometimes referred to as a "film," and the process of forming the layers is sometimes referred to as "film formation."

[0036] <Structure of the blade>

[0037] Figure 1 This is a diagram illustrating an example of the structure of the blade body 1 in this embodiment. (See diagram for details.) Figure 1 As shown, the blade body 1 is configured to include a substrate 100, an adhesive layer 110, a hard coating layer 120, and a fluoropolymer layer 130. Figure 1 In the diagram, as a specific example representing the layered structure of the blade 1, the cross-section of the blade 1 is shown in a plate-like layered manner. However, the layered structure at the blade edge, for example, is shown as follows: Figure 5 As shown.

[0038] <Substrate 100>

[0039] The substrate 100 is a metal that forms the material of the blade 1 before the coating is applied, and is formed of a material containing Fe. The substrate 100 is formed, for example, of stainless steel containing Fe (iron), C (carbon), and Cr (chromium). For example, the substrate 100 has Fe as the main component and contains more than 10.5% Cr and less than 1.2% C.

[0040] <Sealing Layer 110>

[0041] An adhesive layer 110 is formed by laminating it onto a substrate 100. The adhesive layer 110 is disposed between the substrate 100 and the bottommost DLC layer 121 of the hard coating 120.

[0042] The sealing layer 110 is formed of a material comprising a metal or a semi-metal. The metal or semi-metal forming the sealing layer 110 comprises 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).

[0043] The material used to form the adhesive layer 110 is preferably any one of Cr, Ti, W, Si, Nb, B, Zr, Pt, Al, Ni, Cu, Au, Ag, Co, and Zn. More preferably, it is any one of Cr, Ti, W, Si, Nb, B, Zr, and Pt.

[0044] Specifically, the material forming the adhesive layer 110 can be a nitride, carbide, or oxide of these metals or half-metals. The adhesive layer 110 is, for example, Cr, Ti, TiN (titanium nitride), TiC (titanium carbide), CrN (chromium nitride), or CrC (chromium carbide).

[0045] The materials forming the sealing layer 110 and the metal layer 122 can be the same or different, but are preferably the same, and more preferably Cr or Ti.

[0046] The adhesive layer 110 is formed, for example, by sputtering.

[0047] The thickness of the sealing layer 110 is set to be 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.

[0048] <Hard Coating 120>

[0049] like Figure 1 As shown, the hard coating 120 is formed by alternating layers in the stacking direction in the order of DLC layer 121, metal layer 122, DLC layer 121, metal layer 122, and DLC layer 121. Figure 1 As shown, the bottom and top layers of the hard coating 120 are preferably DLC layers 121.

[0050] <DLC Layer 121>

[0051] DLC layer 121 is formed of DLC (Diamond-Like Carbon). DLC layer 121 can also be formed by stacking multiple DLC layers.

[0052] In at least one of the multiple 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 the layer may be less than 40%, but it is preferably 40% or more, more preferably 60% or more.

[0053] DLC layer 121 is formed, for example, by a filtered cathodic arc method. By this filtered cathodic arc method, a DLC layer with an SP3 structure of approximately 40% or more can be formed.

[0054] The thickness of the DLC layer 121 is set to be 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.

[0055] <Metal Layer 122>

[0056] The metal layer 122 is formed of a material comprising a metal or a semi-metal. The metal or semi-metal forming the metal layer 122 comprises 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).

[0057] The preferred material for forming the metal layer 122 is any one of Cr, Ti, W, Si, Nb, B, Zr, Pt, Al, Ni, Cu, Au, Ag, Co, and Zn. More preferably, it is any one of Cr, Ti, W, Si, Nb, B, Zr, and Pt.

[0058] Specifically, the material forming the metal layer 122 can be a nitride, carbide, or oxide of these metals or half-metals. For example, the metal layer 122 can be Cr, Ti, TiN (titanium nitride), TiC (titanium carbide), CrN (chromium nitride), or CrC (chromium carbide). Furthermore, the metal layer 122 can also be formed by stacking multiple metal layers formed of different materials.

[0059] The metal layer 122 is formed, for example, by magnetron sputtering. The deposition rate of the metal layer 122 is faster than that of the DLC layer 121.

[0060] The thickness of the metal layer 122 is set to be 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.

[0061] The total film thickness of the hard coating 120 is set to be 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.

[0062] <Fluoropolymer Layer 130>

[0063] The fluoropolymer layer 130 is a layer formed of a fluorine-containing material and coated onto the surface of the blade body 1. The fluoropolymer layer 130 is, for example, formed of PTFE (polytetrafluoroethylene). This fluoropolymer layer 130 can be constructed using existing technology.

[0064] <Manufacturing Method of Blade Body 1>

[0065] Below, refer to Figure 2 A specific example of the manufacturing method of the blade body 1 is explained. Figure 2 This is a flowchart illustrating the manufacturing method of the blade body 1 in this embodiment.

[0066] like Figure 2 As shown, the prepared substrate 100 is first cleaned by an Ar (argon) ion beam (S1).

[0067] Next, a Cr or Ti film of the bonding layer 110 is formed on the substrate 100 by magnetron sputtering (S2).

[0068] Next, a DLC film of the DLC layer 121 is formed on the sealing layer 110 by means of a cathode arc (S3).

[0069] Next, a Cr or Ti film of the metal layer 122 is formed on the DLC layer 121 by magnetron sputtering (S4).

[0070] Next, the DLC layer 121 is formed on the metal layer 122 by means of a cathode arc (S5).

[0071] Through the above processes, a hard coating 120 having a DLC layer 121, a metal layer 122, and a DLC layer 121 is formed. When it is necessary to further form a film on the DLC layer 121 and the metal layer 122 constituting the hard coating 120 (no in S6), the above-described processes S4 and S5 are repeated. When the film formation of the hard coating 120 is completed (yes in S6), a fluoropolymer layer 130 is formed on the uppermost DLC layer 121 of the hard coating 120 for coating (S7).

[0072] The blade body 1 of this embodiment can be manufactured using the methods described above. Furthermore, the methods described herein are merely examples, and other methods may also be used. The cathode arc used in each film-forming process as a filtered cathode arc method and the magnetron sputtering used as a sputtering method are merely examples, and other methods may also be used.

[0073] <Comparison of cutting performance of blade 1>

[0074] As explained below, the blade 1 of this embodiment has higher cutting performance compared to the structure listed as a comparative example.

[0075] <Experiment 1>

[0076] Figure 3 This is a table showing the results of the first comparative cutting performance experiment. In this experiment, as the hard coating structure, experiments were conducted on (1) a structure using only Cr (comparative example), (2) a structure using only DLC (comparative example), and (3) a structure using the stacked DLC of the embodiment. That is, in the (1) structure using only Cr and (2) the structure using only DLC, the structure of the hard coating 120 is different from the structure of the embodiment.

[0077] In (1) the structure using only Cr, Cr is used as the sealing layer and the hard coating layer, and the film thickness of the coating including the sealing layer and the hard coating layer is set to 50 nm.

[0078] In the structure using only DLC in (2), Cr is used as a 20nm bonding layer and DLC is used as a 105nm hard coating layer, and the film thickness of the coating including the bonding layer and the hard coating layer is set to 125nm. In addition, in this DLC layer, the portion with high hardness of SP3 of 40% or more is about 90nm from the film surface.

[0079] (3) In the stacked DLC structure of the implementation method, Cr is used as a 20 nm bonding layer and as a hard coating layer. The structure is formed by further forming a 15 nm DLC after forming a stacked structure of 3 layers of 15 nm DLC and 15 nm Cr. The film thickness of the coating including the bonding layer and the hard coating layer is set to 125 nm.

[0080] In the experiment, wool felt was cut using a blade with a structure containing these hard coatings. The effect of the surface coating on the cutting performance was measured, including the load required to achieve stable cutting performance on the 10th cut (Cut Test 1) and the load required to cut the wool felt again after a specified durability test (Cut Test 2). That is, the experiment confirmed whether repeated cutting of wool felt would lead to an increase in the load required for cutting and a decrease in cutting performance.

[0081] Experimental results are as follows Figure 3 As shown, in the load required to cut the wool felt again after the durability test (cutting test 2), the structure using the laminated DLC of the embodiment was 4.32 N, which is lower than the 5.14 N of the structure using only Cr and the 5.70 N of the structure using only DLC. In addition, in this experiment, in the structure using only DLC as shown in (2), peeling was sometimes observed on a part of the hard coating after the durability test. This confirms that the structure using the laminated DLC of the embodiment as the hard coating has higher durability than the structure using only Cr or only DLC as the hard coating.

[0082] <Experiment 2>

[0083] Figure 4 This table shows the results of the second cutting performance comparison experiment. In this experiment, although the blade body 1 with the structure of the stacked DLC described in the embodiment was used in all cases, the structure of the hard coating 120 differed. Specifically, the hard coating 120 employed the following two structures:

[0084] (1) A first structure consisting of three layers: a 15nm DLC layer, a 15nm Cr layer (metal layer), and a 15nm DLC layer; and

[0085] (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 any structure, the sealing layer is set to 20 nm Cr, and the film thickness of the coating including the sealing layer and the hard coating layer is set to 65 nm.

[0086] The experiment was conducted using the same method as Experiment 1 described above. The experimental results are as follows: Figure 4 As shown, in the load required to cut the wool felt again after the durability test (cutting test 2), the first structure was 6.10 N and the second structure was 7.55 N. That is, it can be confirmed that the first structure with the outermost surface (top layer) of the hard coating 120 as DLC has higher durability than the second structure with the outermost surface (top layer) of the hard coating 120 as Cr. In other words, it is known that the structure with the outermost surface (top layer) of the hard coating 120 as a DLC layer can achieve higher durability.

[0087] Furthermore, comparing cutting tests 1 and 2 in Experiments 1 and 2, the overall cutting load value of Experiment 1 is lower. This is because the shape of the blade used in Experiment 1 is different from that used in Experiment 2. In other words, comparing cutting performance between Experiment 1 and Experiment 2 is inappropriate.

[0088] <Variation Example>

[0089] The blade body 1 of the above embodiment can be modified as follows. Furthermore, the modifications described below are not intended to limit the invention, but are provided as specific examples.

[0090] The number of DLC layers 121 and metal layers 122 in the hard coating 120 constituting the blade body 1 can be arbitrarily changed. However, for example, if it is set to a structure with 3 DLC layers 121 and 2 metal layers 122 or a structure with 4 DLC layers 121 and 3 metal layers 122, the film structure will not be too complicated, and therefore is preferred.

[0091] The blade body 1 can be used not only as the blade body of a T-shaped razor, but also as the blade body of an L-shaped razor, nail clippers, scissors, kitchen knife, utility knife, slicer, medical scalpel, or special industrial knife. Blade body 1 is particularly suitable for use as the blade body of razors that are replaced periodically. Blade body 1 is suitable for having a thin blade with a thickness of 1.0 mm or less, preferably 0.5 mm or less.

[0092] <Features of the Implementation Method>

[0093] The blade body of one embodiment, described above with examples of embodiments and variations, has the following characteristics.

[0094] The blade body 1 of this embodiment includes: a substrate 100 formed of a material containing Fe; and a hard coating 120 disposed on the substrate 100. The hard coating 120 includes DLC layers 121 and metal layers 122 alternately arranged in the lamination 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 semi-metal. The hard coating 120 includes two or more DLC layers 121. Compared with a structure in which the entire hard coating is formed of DLC, the blade body 1 with this structure can be configured to have thinner individual DLC layers 121. With this structure, while keeping the hard coating 120 to a uniform thickness, the thickness of each DLC layer 121 can be reduced, and a structure less prone to breakage can be constructed by suppressing the stress generated within the DLC layers 121. In addition, the proportion of DLC layers that take longer to form a film can be reduced within the desired film thickness, thereby increasing the speed at which the hard coating 120 is completed, i.e., the film formation speed, and thus improving productivity.

[0095] Furthermore, in the blade body 1, since at least 40% or more of one of the two or more DLC layers 121 is of SP3 structure, it is possible to construct a DLC layer structure with sufficient hardness to be used as a blade body.

[0096] Furthermore, in the blade body 1, the hard coating 120 is set to 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. Based on such a blade body 1, a structure including DLC ​​layers 121 and metal layers 122 alternately arranged in the stacking direction can be adopted, resulting in a well-balanced structure that provides a good shaving feel while maintaining excellent durability and productivity.

[0097] In addition, in the blade body 1, the DLC layer 121 and the metal layer 122 are respectively set to 1nm or more and 150nm or less, preferably 3nm or more and 100nm or less, and more preferably 5nm or more and 80nm or less.

[0098] Furthermore, in the blade body 1, a fluoropolymer layer 130 formed of fluoropolymer is provided on the hard coating 120, and a DLC layer 121 is configured to contact the fluoropolymer layer 130. With such a blade body 1, the structure in which the DLC layer 121 and the fluoropolymer layer 130 are adjacent can be configured to have high cutting performance and durability.

[0099] Furthermore, the blade body 1 is configured such that a sealing layer 110 formed of a material comprising metal or semi-metal is provided between the substrate 100 and the hard coating 120. The hard coating 120 is formed by stacking 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 that order. The first metal layer 122 and the second metal layer 122 are formed of a material comprising Cr, CrN, or CrC.

[0100] On the other hand, the manufacturing method of the blade body 1 in the embodiment includes the following steps:

[0101] (1) Step (S3) on a substrate 100 formed of a material containing Fe to form a first DLC layer 121 formed of a material containing DLC.

[0102] (2) Step (S4) of forming a metal layer 122 on the first DLC layer 121, which is formed of a material comprising a metal or a semi-metal; and

[0103] (3) Step (S5) on metal layer 122, forming a second DLC layer 121 made of DLC-containing material.

[0104] Explanation of reference numerals in the attached figures

[0105] 1. Blade Body

[0106] 100 substrate

[0107] 110 Sealing Layer

[0108] 120 Hard Coating

[0109] 121 DLC layers

[0110] 122 Metal Layer

[0111] 130 Fluoropolymer layer.

Claims

1. A blade, wherein, The blade body has: A substrate formed of a material containing Fe; and A hard coating formed on the substrate, The hard coating comprises DLC layers and metal layers alternately arranged in the stacking direction. The DLC layer is formed of a material containing DLC. The metal layer is formed of a material comprising metals or semi-metals. The hard coating comprises two or more of the DLC layers.

2. The blade body according to claim 1, wherein, In at least one of the two or more DLC layers, more than 40% is an SP3 structure.

3. The blade body according to claim 1, wherein, The hard coating is 5nm or larger and 1000nm or smaller.

4. The blade body according to claim 1, wherein, The hard coating is 10nm or larger and 500nm or smaller.

5. The blade body according to claim 1, wherein, The DLC layer and the metal layer are respectively above 1nm and below 150nm.

6. The blade body according to claim 1, wherein, The DLC layer and the metal layer are respectively 3nm or larger and 100nm or smaller.

7. The blade body according to claim 1, wherein, The hard coating also includes a fluoropolymer layer formed of fluoropolymer. The DLC layer is configured to contact the fluoropolymer layer.

8. The blade body according to claim 7, wherein, An adhesive layer made of a material comprising metal or semi-metal is further provided between the substrate and the hard coating. The hard coating layer is formed by stacking the first DLC layer, the first metal layer, the second DLC layer, the second metal layer, and the third DLC layer in that order. The first metal layer and the second metal layer are formed of a material containing Cr, CrN or CrC.

9. A method for manufacturing a blade, wherein, The method for manufacturing the blade body includes the following steps: The step of forming a first DLC layer of a material containing DLC ​​on a substrate formed of a material containing Fe; The step of forming a metal layer on the first DLC layer, which is formed of a material comprising a metal or a semi-metal; as well as The step of forming a second DLC layer on the metal layer, which is made of a material containing DLC.

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