Razor blades containing parylene C and parylene N

Abstract

This disclosure relates to a razor blade having a lubricating layer containing parylene C and parylene N. This disclosure also relates to a razor cartridge having at least one razor blade having a lubricating layer containing parylene C and parylene N. This disclosure further relates to a method for coating a razor blade with a lubricating layer containing parylene C and parylene N.

Description

Technical Field

[0001] (Cross - reference to Related Applications) This application claims priority to European Patent Application Publication No. 23174333.7, filed on May 19, 2023, the entire content of which is incorporated herein by reference.

[0002] (Field of the Invention) The present invention relates to the field of razor blades. More specifically, the present invention relates to a razor blade including a lubricating layer.

Background Art

[0003] A razor head (also known as a safety razor head, razor cartridge, or safety razor cartridge) is typically part of a shaving razor assembly that includes a razor handle. The razor head generally includes one or more cutting members, each cutting member including a razor blade, and is disposed between the longitudinal front surface and the longitudinal rear surface of the razor head. In use, the user holds the razor handle in the shaving direction and brings the razor head into contact with a portion of the skin. By moving the razor head in the shaving direction, unwanted hair is removed.

[0004] Razor blades for razor cartridges typically contain a lubricating layer. This lubricating layer is usually applied by a coating and is sometimes called a lubricating coating. The lubricating layer is designed to reduce the cutting force required during the shaving process. By reducing the required cutting force, the razor glides more smoothly during the shaving motion, making it easier to use. In addition, reducing the required cutting force can reduce hair pulling and the resulting pulling of hair follicles, which can cause discomfort to the user. Furthermore, the lubricating layer can also reduce friction between the razor blade and the user's skin, which also improves the razor's glide. Moreover, the reduced cutting force and improved glide can result in a better shaving result, for example, with less stubble, cuts, and nicks.

[0005] Generally, the lubricating coating on razor blades is made from perfluoroalkyl substances such as polytetrafluoroethylene (PTFE) or polyfluoroalkyl substances (PFAS). PTFE-coated razor blades are effective at cutting hair, causing little friction to the skin and low pulling on the hair.

[0006] However, PTFE coatings also have drawbacks. First, PTFE coatings are generally applied by spraying PTFE particles onto the razor blade and then sintering the sprayed particles at a temperature exceeding the melting point of PTFE. The resulting coating may lack uniformity, which can lead to a decrease in the shaving performance of the razor blade. Furthermore, the temperature rise during the sintering process can reduce the hardness and corrosion resistance of the razor blade. In addition, because PTFE is a material that is very difficult to decompose, it is a subject of environmental concern.

[0007] This disclosure aims to address one or more of the aforementioned problems regarding the optimization of lubrication layers. [Overview of the project]

[0008] In a first aspect, the disclosure relates to a razor blade provided with a lubricating layer, wherein the lubricating layer comprises parylene C and parylene N.

[0009] In some embodiments, the razor blade may include a tip edge, and the lubricating layer may be provided on the tip edge.

[0010] In some embodiments, the razor blade may be configured to be located within a razor cartridge.

[0011] In some embodiments, the lubricating layer may include a first layer and a second layer, the first layer may contain parylene C, and the second layer may contain parylene N.

[0012] In some embodiments, a hard coating may be additionally provided on the razor blade.

[0013] In some embodiments, the hard coating may include ceramic, metallic, and / or non-metallic coatings.

[0014] In some embodiments, the ceramic may include borides and / or carbides, and in particular titanium diboride.

[0015] In some embodiments, the ceramic may include titanium, boron, and carbon.

[0016] In some embodiments, the non-metallic coating may include diamond-like carbon.

[0017] In some embodiments, the hard-coated metal may contain chromium.

[0018] In some embodiments, a capping layer may be additionally provided on the razor blade.

[0019] In some embodiments, the capping layer may contain a metal, and more specifically, chromium or titanium, and in particular, the capping layer may contain titanium.

[0020] In some embodiments, the capping layer may be placed between the hard coating and the lubricating layer.

[0021] In some embodiments, the capping layer may be placed directly on the razor blade, and the lubricating layer may be placed on top of the capping layer.

[0022] In some embodiments, the capping layer may be placed directly on the razor blade, the first layer may be placed on the capping layer, and the second layer may be placed on the first layer.

[0023] In some embodiments, the first layer may be placed on a capping layer, and the second layer may be placed on the first layer.

[0024] In some embodiments, the capping layer may have a thickness of about 5 nm to about 70 nm, more specifically, about 10 nm to about 60 nm, and in particular about 20 nm to about 50 nm.

[0025] In some embodiments, the lubricating layer may have a thickness of about 0.005 μm to about 5 μm, more specifically, about 0.02 μm to about 2 μm, and in particular about 0.1 μm to about 1 μm.

[0026] In some embodiments, the lubricating layer does not have to contain pores, and in particular does not have to contain pores having a diameter of about 5 nm to about 200 nm.

[0027] In some embodiments, the lubricating layer may contain less than 1% by weight, more specifically less than 0.1% by weight, of polytetrafluoroethylene, and in particular may not contain or may substantially not contain polytetrafluoroethylene.

[0028] In some embodiments, the razor blade may include an intermediate layer between the hard coating and the razor blade, and the intermediate layer may contain a metal, more specifically niobium and / or titanium, even more specifically titanium, and in particular metallic titanium.

[0029] In some embodiments, the intermediate layer may be provided directly on the razor blade. Alternatively, in some embodiments, the hard coating may be provided directly on the razor blade.

[0030] In some embodiments, the razor blade contains a metal, particularly stainless steel, consists essentially of a metal, particularly stainless steel, or consists of a metal, particularly stainless steel.

[0031] In some embodiments, the cross-section of the tip edge may have a substantially symmetric tapered shape terminating at the cutting edge, the cross-section may have a central longitudinal axis starting from the cutting edge, and the tip edge may have a thickness of 1.5 μm to 2.4 μm measured at a distance of 5 μm along the central longitudinal axis from the cutting edge.

[0032] In a second aspect, the present disclosure relates to a razor cartridge comprising at least one razor blade according to the first aspect.

[0033] In a third aspect, the present disclosure relates to a method for coating a razor blade, the method comprising coating the razor blade with parylene C, more specifically by chemical vapor deposition, and coating the razor blade with parylene N, more specifically by chemical vapor deposition.

[0034] In some embodiments, coating the razor blade with parylene C may be performed before coating the razor blade with parylene N.

[0035] In some embodiments, the method may include coating the razor blade with titanium before coating the razor blade with parylene C and / or parylene N.

[0036] In some embodiments, coating a razor blade with parylene C by chemical vapor deposition may include sublimating a dimer of parylene C precursor, thermally decomposing the sublimated dimer of parylene C precursor to obtain a parylene C precursor monomer, and depositing the parylene C precursor monomer onto the razor blade.

[0037] In some embodiments, the sublimation of the parylene C precursor dimer may be carried out at a temperature of about 130°C to about 190°C, more specifically about 150°C to about 180°C, and / or at a pressure of about 0.5 Torr to about 2 Torr, more specifically about 0.8 Torr to about 1.2 Torr.

[0038] In some embodiments, the thermal decomposition of the sublimated parylene C precursor dimer may be carried out at a temperature of about 400°C to about 800°C, more specifically about 500°C to about 700°C, and / or at a pressure of about 0.2 Torr to about 1 Torr, more specifically about 0.4 Torr to about 0.6 Torr.

[0039] In some embodiments, the deposition of parylene C precursor monomers may be carried out at a temperature of about 10°C to about 50°C, more specifically about 17°C to about 28°C, and / or at a pressure of about 0.01 Torr to about 0.5 Torr, more specifically about 0.05 Torr to about 0.2 Torr.

[0040] In some embodiments, coating a razor blade with parylene N by chemical vapor deposition may include sublimating a dimer of parylene N precursor, thermally decomposing the sublimated dimer of parylene N precursor to obtain a parylene N precursor monomer, and depositing the parylene N precursor monomer onto the razor blade.

[0041] In some embodiments, the sublimation of the parylene N precursor dimer may be carried out at a temperature of about 130°C to about 190°C, more specifically about 150°C to about 180°C, and / or at a pressure of about 0.5 Torr to about 2 Torr, more specifically about 0.8 Torr to about 1.2 Torr.

[0042] In some embodiments, the thermal decomposition of the sublimated parylene N precursor dimer may be carried out at a temperature of about 400°C to about 800°C, more specifically about 500°C to about 700°C, and / or at a pressure of about 0.2 Torr to about 1 Torr, more specifically about 0.4 Torr to about 0.6 Torr.

[0043] In some embodiments, the deposition of parylene N precursor monomers may be carried out at a temperature of about 10°C to about 50°C, more specifically about 17°C to about 28°C, and / or at a pressure of about 0.01 Torr to about 0.5 Torr, more specifically about 0.05 Torr to about 0.2 Torr.

[0044] In some embodiments, the method for coating the razor blade may further include an annealing step, in particular the razor blade may be annealed in an inert gas atmosphere at a temperature of about 300°C to about 400°C, more specifically at a temperature of about 330°C to about 370°C, especially after the deposition of parylene C and / or parylene N.

[0045] In some embodiments, the razor blade may be annealed for a duration of about 10 seconds to about 20 minutes, more specifically for a duration of about 1 minute to about 5 minutes. [Brief explanation of the drawing]

[0046] [Figure 1] This is a schematic cross-sectional view of the edge of a razor blade, where a lubricating coating containing parylene N and parylene C is provided on the edge. [Figure 2]This is a schematic cross-sectional view of the edge of a razor blade, where a lubricating coating containing parylene N and parylene C is provided on the edge of the blade above the intermediate layer, hard coating, and capping layer. [Figure 3] This is a schematic cross-sectional view of the edge of a razor blade, where a lubricating coating containing parylene N and parylene C is provided on the edge of the blade above the capping layer. [Figure 4] This graph shows a comparison of the cutting force of the first sample lot with the cutting forces of the first, second, and third comparison sample lots. [Figure 5] This graph shows a comparison between the cutting force of the first sample lot and the cutting force of the second sample lot. [Figure 6] This graph shows a comparison between the cutting force of the first sample lot and the cutting force of the third sample lot. [Figure 7] This graph shows a comparison between the cutting force of the third sample lot and the cutting force of the fourth comparison sample lot. [Figure 8] This graph shows a comparison between the cutting force of the second sample lot and the cutting force of the fifth comparison sample lot. [Modes for carrying out the invention]

[0047] The present disclosure is described in detail below. Terms or words used in the description and embodiments of this disclosure should not be construed to be limited to their general language or dictionary meanings, but should be construed to have their ordinary technical meanings as established in the art, unless otherwise defined in the following description. “Modes for Carrying Out the Invention” refers to specific embodiments to better illustrate this disclosure, but it should be understood that the presented disclosure is not limited to these specific embodiments.

[0048] As mentioned above, the lubricating coating on razor blades is generally made of perfluoroalkyl substances such as polytetrafluoroethylene (PTFE) or polyfluoroalkyl substances (PFAS) because PTFE-coated razor blades are effective at cutting hair, cause little friction to the skin, and have a low degree of pulling on the hair.

[0049] However, PTFE coatings can lack uniformity as a result of deposition due to particle spraying, which can lead to a decrease in the shaving performance of razor blades. Furthermore, the (prolonged) temperature rise during the sintering process can reduce the hardness and corrosion resistance of the razor blades. In addition, PTFE is a material that is very difficult to decompose, making it a subject of environmental concern.

[0050] A currently known alternative to PTFE coatings (or any other PFAS coating) is a coating containing a polymer selected from the parylene group, which also exhibits a low coefficient of friction.

[0051] Surprisingly, it was found that coating razor blades with a combination of parylene C and parylene N could result in lower cutting force, particularly compared to any lubricating layer containing parylene C, parylene N, or parylene F alone.

[0052] Accordingly, in the first aspect, the present disclosure relates to a razor blade provided with a lubricating layer, wherein the lubricating layer comprises parylene C and parylene N.

[0053] The term "parylene" refers to a polymer whose skeleton consists of a para-benzenediyl ring-C6H4 linked by 1,2-ethanediyl crosslinks-CH2-CH2-. Substitution of the para-benzenediyl ring results in different types of parylene.

[0054] Parylene N (or parylene N) is an unsubstituted parylene. Parylene N can be obtained by polymerization of paraxylylene. Parylene N consists of the following repeating units.

[0055] [ka]

[0056] Parylene C (or parylene C) is chlorinated parylene. Parylene C can be obtained by polymerization of 2,8-dichlorotricyclo[8.2.2.24,7]hexadeca-1(12),4,6,10,13,15-hexaene. Parylene C consists of the following repeating units.

[0057] [ka]

[0058] In some embodiments, the razor blade includes, or is essentially made of, a metal, particularly stainless steel. Stainless steel razor blades can exhibit high strength, hardness, and corrosion resistance. Furthermore, stainless steel razor blades can be processed more easily than, for example, ceramic razor blades. The razor blade may be polished to form a rim. More specifically, the razor blade may be shaped to terminate at a tip rim having substrate sides converging toward the substrate edge. Thus, in some embodiments, the razor blade may include a tip rim, and a lubricating layer may be provided on the tip rim.

[0059] When referring to a tip edge with a lubricating layer, it should be understood that such a reference refers not merely to the exact geometric edge of the razor blade, but rather to the edge considering the cutting action performed by the razor blade. Therefore, the term tip edge also means that the portion of the razor blade side directly adjacent to the exact geometric edge of the tip edge is also included. In exemplary embodiments, the region forming the tip edge extends along the central longitudinal axis of the tip edge, away from the exact geometric edge of the tip edge, over distances of approximately 5 μm or less, approximately 10 μm or less, approximately 15 μm or less, approximately 25 μm or less, approximately 50 μm or less, approximately 75 μm or less, approximately 100 μm or less, approximately 125 μm or less, approximately 150 μm or less, approximately 175 μm or less, or approximately 200 μm or less. The lubricating layer may generally follow the surface and contour of the tip edge that lies beneath it. In particular, the lubricating layer may form the outermost layer positioned on the razor blade. Therefore, the lubricating layer may form the edge of the blade.

[0060] In some embodiments, the razor blade may be configured to be placed within a razor cartridge. The use of a lubricating layer may be particularly beneficial for razor blades used in a razor cartridge.

[0061] In some embodiments, the lubricating layer may consist of parylene C and parylene N, or essentially parylene C and parylene N. In some embodiments, the lubricating layer may include a first layer and a second layer, the first layer may contain parylene C, and the second layer may contain parylene N. In some embodiments, the first layer may consist of parylene C, or essentially parylene C. In some embodiments, the second layer may consist of parylene N, or essentially parylene N. In some embodiments, the first layer may contain parylene N, and the second layer may contain parylene C.

[0062] In some embodiments, a hard coating may be additionally provided on the razor blade. The hard coating can improve the hardness of the razor blade, thereby improving the durability of the blade, in particular extending its service life. In some embodiments, the hard coating may include ceramic, metallic, and / or nonmetallic coatings. In some embodiments, the ceramic may include borides and / or carbides, and in particular titanium diboride. In some embodiments, the ceramic may include titanium, boron, and carbon. In some embodiments, the metallic hard coating may include chromium. In some embodiments, the nonmetallic coating may include diamond-like carbon.

[0063] When referring to hard coatings, it should be understood that the coating itself may be harder than the coated tip edge, and / or the coated tip edge may be hardened as a whole compared to the uncoated substrate. The hardness of a hard coating or coated tip edge can be measured using a nanoindenter. During the nanoindentation process, a hard tip with known properties (mechanical properties, shape, tip radius, etc.) penetrates a sample of the hard coating to be analyzed. For example, a Berkovich indenter can be used for indentation testing. The load applied to the tip of the indenter was increased as the tip penetrated further into the specimen until a penetration depth of 50-100 nm was reached. At this point, the load was held for a certain period of time, and then the indenter was removed. The area of ​​the residual indentation in the sample was measured. Hardness H is defined as the maximum load P. max It is defined as the result of dividing by the residual indentation area A.

[0064]

number

[0065] In some embodiments, the hard coating or tip edge may exhibit a hardness of about 5 GPa to about 30 GPa, more specifically about 10 GPa to about 20 GPa.

[0066] Parylene N and Parylene C may exhibit low adhesion to razor blades or hard coatings. Therefore, adhesion can be improved by providing a capping layer. Surprisingly, Parylene N and Parylene C have been found to exhibit good adhesion to titanium. It should be noted that perfluoroalkyl substances such as polytetrafluoroethylene (PTFE) or polyfluoroalkyl substances (PFAS) do not exhibit suitable adhesion to titanium. Furthermore, surprisingly, titanium as a capping layer has been found to reduce the required cutting force compared to chromium. Therefore, in some embodiments, a capping layer may be provided on the razor blade. In some embodiments, the capping layer may be placed between the hard coating and the lubricating layer. In some embodiments, the capping layer may contain a metal, and more specifically, the capping layer may contain chromium or titanium, and more specifically, the capping layer may contain titanium, in particular metallic titanium. If the capping layer contains chromium, the chromium may also be in the form of metallic chromium. In some embodiments, the capping layer may be made of titanium (as detailed above) or may be essentially made of titanium. The term “metallic titanium” is well known and, in particular, belongs to its general meaning in the art. Additionally or alternatively, the term “metallic titanium” may refer to the reduced state of titanium, where the oxidation number of titanium is 0. Additionally or alternatively, the term “metallic titanium” may refer to titanium atoms contained in the capping layer that form metallic bonds with each other.

[0067] In some embodiments, the lubricating layer may form the outermost layer on the razor blade, and in particular, a second layer containing parylene N may form the outermost layer on the razor blade. Therefore, the first layer may be located closer to the razor blade than the second layer, and the hard coating may be located closer to the razor blade than the first layer. In some embodiments, the first layer may be located on the capping layer, and the second layer may be located on the first layer.

[0068] In some embodiments, the capping layer may be placed directly on the razor blade, and the lubricating layer may be placed on top of the capping layer. In some embodiments, the capping layer may be placed directly on the razor blade, the first layer may be placed on top of the capping layer, and the second layer may be placed on top of the first layer. In this case, the razor blade may not include a hard coating.

[0069] In some embodiments, the capping layer may have a thickness of about 5 nm to about 70 nm, more specifically, about 10 nm to about 60 nm, and in particular about 20 nm to about 50 nm.

[0070] In some embodiments, the lubricating layer may have a thickness of about 0.005 μm to about 5 μm, more specifically, about 0.02 μm to about 2 μm, and in particular about 0.1 μm to about 1 μm.

[0071] In some embodiments, the lubricating layer may contain, specifically not contain, or substantially not contain, less than 1% by weight, more specifically less than 0.1% by weight, of polytetrafluoroethylene (PTFE) or any other perfluoroalkyl or polyfluoroalkyl substance (PFAS). As described above, a lubricating layer containing parylene N and parylene C can be used to replace a lubricating coating containing PTFE (or any other PFAS). Furthermore, as described above, the lubricating layer can be applied by thin-film deposition techniques, in contrast to PTFE coatings which require a spraying process. Thin-film deposition techniques can enable the deposition of a more uniform layer compared to spraying. Furthermore, thin-film deposition techniques can enable the deposition of a layer with fewer defects compared to spraying. Therefore, in some embodiments, the lubricating layer may not contain pores, and in particular may not contain pores having a diameter of about 5 nm to about 200 nm.

[0072] Some hard coatings, particularly ceramic hard coatings, can exhibit better adhesion to the razor blade when the intermediate layer bonds the hard coating to the razor blade. Therefore, in some embodiments, the razor blade may include an intermediate layer between the hard coating and the razor blade. In some embodiments, the intermediate layer may include a metal, more specifically niobium and / or titanium, even more specifically titanium, and particularly metallic titanium. If the intermediate layer includes niobium, the niobium may be in the form of metallic niobium. In some embodiments, the intermediate layer may consist of titanium or niobium, particularly titanium (as detailed above), or may essentially consist of titanium or niobium, particularly titanium.

[0073] In some embodiments, the intermediate layer may be provided directly on the razor blade. Alternatively, in some embodiments, the hard coating may be provided directly on the razor blade.

[0074] Figure 1 shows the tip edge 100 of a first exemplary razor blade 10 according to a first embodiment. A first layer 102 containing parylene C is provided on the tip edge 100. A second layer 104 containing parylene N is provided on the first layer 102, specifically as the outermost layer provided on the razor blade 10.

[0075] Figure 2 shows the tip edge 200 of a second exemplary razor blade 20 according to the first embodiment. An intermediate layer 206 is provided on the tip edge 200, and a hard coating 208 is provided on top of it. The hard coating 208 of the exemplary razor blade 20 may be ceramic in particular. A capping layer 210 containing titanium is provided on the hard coating 208. Next, a first layer 202 containing parylene C is provided on the capping layer 210. A second layer 204 containing parylene N is then provided on the first layer 202, particularly as the outermost layer.

[0076] Figure 3 shows the tip edge 300 of a third exemplary razor blade 30 according to the first embodiment. A capping layer 310 is directly provided on the tip edge 300. Some hard coatings, such as chromium or titanium, may not require an intermediate layer. A first layer 302 containing parylene C is provided on the capping layer 310. A second layer 304 containing parylene N is provided on the first layer 302.

[0077] As will be described in more detail below, the lubricating layer, particularly parylene N and parylene C, can be applied by thin-film formation techniques. In particular, the lubricating layer may be deposited by chemical vapor deposition. As a result, the lubricating layer can be applied to a relatively small tip edge. In particular, the lubricating layer can be applied to a smaller tip edge compared to conventional PTFE coatings prepared by spraying. By reducing the tip edge, the cutting force required during the shaving operation can be reduced. Therefore, in some embodiments, the cross section of the tip edge may have a substantially symmetrical tapered shape terminating at the cutting edge, the cross section may have a central longitudinal axis starting from the cutting edge, and the tip edge may have a thickness of 1.5 μm to 2.4 μm measured at a distance of 5 μm from the cutting edge along the central longitudinal axis. In some embodiments, the edge of the blade has a thickness of about 4.6 μm to about 6.8 μm, particularly about 4.62 to about 6.74 μm, measured at a distance of about 20 μm from the cutting edge along the central longitudinal axis. In some embodiments, the edge of the blade has a thickness of approximately 10.3 μm to 14.4 μm, particularly about 10.32 to 14.35 μm, measured at a distance of approximately 50 μm from the cutting edge along the central longitudinal axis. In some embodiments, the edge of the blade has a thickness of approximately 19.8 μm to 27.6 μm, particularly about 19.82 to 27.52 μm, measured at a distance of approximately 100 μm from the cutting edge along the central longitudinal axis.

[0078] The razor blade described above can be manufactured by any preferred means. More specifically, the preparation and polishing of the blade base material can be carried out by any preferred means, for example, as disclosed in U.S. Patent Application Publication 2017 / 136641(A1), which is incorporated by reference in whole.

[0079] In a second aspect, the disclosure relates to a razor cartridge comprising at least one razor blade according to the first aspect. As described above, a lubricating layer may be particularly beneficial for a razor blade for a razor cartridge.

[0080] In a third aspect, the disclosure relates to a method for coating a razor blade, the method comprising coating the razor blade with parylene C, more specifically by chemical vapor deposition, and coating the razor blade with parylene N, more specifically by chemical vapor deposition.

[0081] Examples of CVD techniques include low-pressure CVD (LPCVD), atmospheric-pressure CVD (APCVD), atomic layer deposition (ALD), and metal-organic CVD (MOCVD) using precursors.

[0082] In some embodiments, coating the razor blade with parylene C may be performed before coating the razor blade with parylene N.

[0083] In some embodiments, the method may include coating the razor blade with titanium before coating the razor blade with parylene C and / or parylene N. In some embodiments, coating the razor blade with titanium may be done by sputtering. In some embodiments, coating the razor blade with a capping layer containing titanium may be done by DC sputtering, high-frequency sputtering, Closed Field Unbalanced Magnetron Sputtering (CFUMS), ion beam sputtering, cathode arc deposition, and High-Power Impulse Magnetron Sputtering (HiPIMS), in particular, using a sintered titanium target in an Ar atmosphere.

[0084] In some embodiments, coating a razor blade with parylene C by chemical vapor deposition may include the steps of sublimating a dimer of parylene C precursor, thermally decomposing the sublimated dimer of parylene C precursor to obtain a parylene C precursor monomer, and depositing the parylene C precursor monomer onto the razor blade so that the parylene C precursor monomer polymerizes. The parylene C precursor monomer may polymerize on the razor blade during or after deposition. Polymerization of the parylene C precursor monomer can result in the formation of a parylene C layer.

[0085] In some embodiments, the sublimation of the parylene C precursor dimer may be carried out at a temperature of about 130°C to about 190°C, more specifically about 150°C to about 180°C, and / or at a pressure of about 0.5 Torr to about 2 Torr, more specifically about 0.8 Torr to about 1.2 Torr.

[0086] In some embodiments, the thermal decomposition of the sublimated parylene C precursor dimer may be carried out at a temperature of about 400°C to about 800°C, more specifically about 500°C to about 700°C, and / or at a pressure of about 0.2 Torr to about 1 Torr, more specifically about 0.4 Torr to about 0.6 Torr.

[0087] In some embodiments, the deposition of parylene C precursor monomers may be carried out at a temperature of about 10°C to about 50°C, more specifically about 17°C to about 28°C, and / or at a pressure of about 0.01 Torr to about 0.5 Torr, more specifically about 0.05 Torr to about 0.2 Torr.

[0088] In some embodiments, the method may include a film growth step after the deposition of parylene C precursor monomers, the film growth step being carried out at a temperature of about 50°C to about 100°C, more specifically, about 60°C to about 80°C, and / or at a pressure of about 0.0001 Torr to about 0.05 Torr, more specifically, at a pressure of about 0.0005 Torr to about 0.002 Torr. The film growth step can better polymerize the parylene C precursor monomers deposited on the razor blade.

[0089] In some embodiments, coating a razor blade with parylene N by chemical vapor deposition may include the steps of sublimating a dimer of parylene N precursor, thermally decomposing the sublimated dimer of parylene N precursor to obtain a parylene N precursor monomer, and depositing the parylene N precursor monomer onto the razor blade so that the parylene N precursor monomer polymerizes. The parylene N precursor monomer may polymerize on the razor blade during or after deposition. Polymerization of the parylene N precursor monomer can result in the formation of a parylene N layer.

[0090] In some embodiments, the sublimation of the parylene N precursor dimer may be carried out at a temperature of about 130°C to about 190°C, more specifically about 150°C to about 180°C, and / or at a pressure of about 0.5 Torr to about 2 Torr, more specifically about 0.8 Torr to about 1.2 Torr.

[0091] In some embodiments, the thermal decomposition of the sublimated parylene N precursor dimer may be carried out at a temperature of about 400°C to about 800°C, more specifically about 500°C to about 700°C, and / or at a pressure of about 0.2 Torr to about 1 Torr, more specifically about 0.4 Torr to about 0.6 Torr.

[0092] In some embodiments, the deposition of parylene N precursor monomers may be carried out at a temperature of about 10°C to about 50°C, more specifically about 17°C to about 28°C, and / or at a pressure of about 0.01 Torr to about 0.5 Torr, more specifically about 0.05 Torr to about 0.2 Torr.

[0093] In some embodiments, the method may include a film growth step after the deposition of parylene N precursor monomers, the film growth step being carried out at a temperature of about 50°C to about 100°C, more specifically, about 60°C to about 80°C, and / or at a pressure of about 0.0001 Torr to about 0.05 Torr, more specifically, at a pressure of about 0.0005 Torr to about 0.002 Torr. The film growth step can better polymerize the parylene N precursor monomers deposited on the razor blade.

[0094] In some embodiments, the method for coating the razor blade may further include an annealing step, in particular the razor blade may be annealed in an inert gas atmosphere at a temperature of about 300°C to about 400°C, more specifically about 330°C to about 370°C, especially after the deposition of parylene C and / or parylene N, or after the film growth step if one is performed.

[0095] In some embodiments, the razor blade may be annealed for a duration of about 10 seconds to about 20 minutes, more specifically about 1 minute to about 5 minutes. Annealing for more than 20 minutes may reduce the hardness and / or corrosion resistance of the razor blade. In some embodiments, the razor blade may be annealed in an inert atmosphere, more specifically a nitrogen atmosphere or an argon atmosphere. The annealing process can make it possible to reduce the cutting force required during the shaving operation. Although not bound by theory, it is thought that annealing can increase the crystallinity of parylene C and / or parylene N, which can result in an increase in the strength of parylene, thereby reducing the required cutting force. Furthermore, the softening of parylene C and / or parylene N during the annealing process can also further improve the uniformity of the lubricating layer. The annealing process can reduce surface defects in the lubricating layer, such as its porosity.

[0096] As described above, a hard coating may be provided on the razor blade. Therefore, the razor blade may be coated with a hard coating, particularly before being coated with the first layer. The razor blade may be coated with a hard coating using, for example, a chemical vapor deposition process or a physical vapor deposition process. Exemplary hard coating deposition processes are described in U.S. Patent Application Publication 2018 / 215056(A1) and U.S. Patent No. 10,442,098(B2), both of which are incorporated herein by reference in their entirety.

[0097] As described above, an intermediate layer and / or a capping layer may be provided on the razor blade. Therefore, the razor blade may be coated with an intermediate layer, in particular before being coated with a hard coating. Additionally or alternatively, the razor blade may be coated with a capping layer, in particular after being coated with a hard coating. Therefore, in some embodiments, coating the razor blade with an intermediate layer and / or a capping layer, in particular an intermediate layer and / or capping layer containing titanium, may be carried out by sputtering. In some embodiments, coating the razor blade with an intermediate layer and / or capping layer can be carried out by DC sputtering, high-frequency sputtering, closed-field unequilibrium magnetron sputtering (CFUMS), ion beam sputtering, cathode arc deposition, and high-power impulse magnetron sputtering (HiPIMS), in particular using a sintered metal target, in particular a sintered titanium target, in an Ar atmosphere.

[0098] Experiment section Sample preparation Three sample lots (the first, second, and third sample lots) were prepared according to the first embodiment. Furthermore, three comparative sample lots (the first, second, and third comparative sample lots) unrelated to the first embodiment were also prepared.

[0099] 1. First comparative sample lot (Parylene C) A first comparative sample lot was prepared, containing a capping layer with titanium and a second layer with parylene-C. The first comparative sample lot was prepared by the following procedure.

[0100] Ten stainless steel razor blades were stacked on a blade carrier in a rotating jig of the deposition chamber. The deposition chamber was equipped with a titanium target and a TiB2 target. If, for example, a chromium layer was deposited as a capping layer, the deposition chamber was also equipped with a chromium target.

[0101] Prior to the deposition of the intermediate layer, a series of preparatory steps were performed, including sputter etching. The deposition chamber was evacuated to a base pressure of 10⁻⁵ Torr using a vacuum. Next, Ar gas was introduced into the chamber from an Ar gas source, and the pressure was increased to 8 mTorr (8.10⁻³ Torr). The loaded bayonet was rotated at a constant speed of 6 rpm in a rotating fixture using a motor, and all targets, especially the Ti target and TiB2 target, were operated under a DC current control of 0.2 amperes. A DC voltage of 200-600 V was applied to the stainless steel blade for 4 minutes. The sputter etching process helps to remove impurities from the blade substrate and target by impacting them with argon ions.

[0102] After that, the coating process itself was carried out.

[0103] In the first series of steps for forming the intermediate layer, the chamber pressure was adjusted to 3 mTorr. The Ti target and TiB2 target(s) were operated under DC current control of 3 amperes and 0.2 amperes, respectively, while a DC voltage of 0 to 50 V was applied to the rotating blade. The deposition time was adjusted to deposit a 20 to 40 nm Ti layer on the edge of the blade sample.

[0104] In the second series of steps, a TiB2 hard coating was deposited after the deposition of the Ti interlayer. The hard coating was also deposited at a pressure of 3 mTorr. The Ti target, Cr target (if present), and TiB2 target were operated simultaneously, with the current to the Cr and Ti targets set to 0.2 amps and the current to the TiB2 target set to 3 amps. The current to the Ti and Cr targets was used to prevent elemental deposition on the targets. A DC bias voltage of 150-350 V was applied to the rotating blade. The deposition time was adjusted to deposit a 150-300 nm TiB2 layer on the Ti layer.

[0105] In the third series of steps, a capping layer was deposited on the hard coating. The capping layer was also deposited at a pressure of 3 mTorr. Next, the capping layer containing titanium was deposited with the chamber pressure adjusted to 3 mTorr. The titanium target was operated under a DC current control of 3 to 10 amperes while a DC voltage of 0 to 50 V was applied to the rotating blade. By adjusting the deposition time, a titanium layer with a thickness of 20 to 40 nm was deposited on the razor blade.

[0106] In a fourth series of steps for forming a lubricating layer, the rotating fixture was moved to a second deposition chamber equipped with a vaporizer, a pyrolysis chamber, a deposition chamber, a cold trap, and a mechanical vacuum pump. The second chamber was then evacuated to a base pressure of 1 Torr. The parylene C precursor dimer was evaporated at a temperature of 175°C. The pressure in the chamber was then reduced to 0.5 Torr, and the parylene C precursor dimer was pyrolyzed at a temperature of 680°C to form parylene C precursor monomers. The formed parylene C precursor monomers were then deposited at a temperature of 25°C and a pressure of 0.1 Torr. The temperature was then raised to 70°C at a pressure of 0.001 Torr.

[0107] In a fifth step in the annealing process for the razor blades, the second chamber was filled with argon at atmospheric pressure and heated to 350°C for 10 minutes to anneal the razor blades. After cooling to room temperature, the finished razor blades (the first comparative sample lot) were removed from the second chamber.

[0108] 2. Second comparative sample lot (Parylene-N) The second comparative sample lot was prepared in the same manner as the first comparative sample lot, except that in the fourth series of steps, a parylene-N precursor dimer was used instead of a parylene-C precursor dimer.

[0109] 3. Third comparative sample lot (Parylene-F) The third comparative sample lot was prepared in the same manner as the first comparative sample lot, except that in the fourth series of steps, a parylene-F precursor dimer was used instead of a parylene-C precursor dimer.

[0110] 4. Fourth comparative sample lot (chromium + parylene-N) A fourth comparative sample lot was prepared in the same way as the second comparative sample lot, but instead of using titanium in the third series of steps, the razor blade was coated with chromium.

[0111] 5. Fifth comparative sample lot (titanium + parylene-N, no annealing) The fifth comparative sample lot was prepared in the same manner as the second comparative sample lot, but the fifth series of steps was omitted. Therefore, the fifth comparative sample lot was not annealed.

[0112] 6. First sample lot (Titanium + Parylene-C + Parylene-N) A first sample lot according to the first embodiment was prepared in the same manner as the first comparative sample lot, except that after the deposition of parylene-C, the fourth series of steps was repeated using a parylene-N precursor dimer to deposit a first layer containing parylene-C and a second layer containing parylene-N.

[0113] 7. Second sample lot (Titanium + Parylene-C + Parylene-N, no annealing) A second sample lot according to the first embodiment was prepared by coating the razor blades in the same manner as the first sample lot according to the first embodiment, but the fifth series of steps was not performed. Therefore, the second sample lot was not annealed.

[0114] 8. Third sample lot (chromium + parylene-C + parylene-N) A third sample lot according to the first embodiment was prepared in the same manner as the first sample lot according to the first embodiment, except that the razor blade was coated with chromium instead of titanium in the third series of steps.

[0115] Cutting force experiment The cutting forces of the first, second, and third sample lots according to the first embodiment, as well as the cutting forces of the first, second, and third comparative sample lots, were determined.

[0116] Ten blades per sample lot were each used to make 10 consecutive cuts on a moving wool felt. These blades were individually placed in holders connected to load cells. The load cells were used to measure the load on the blades during the cutting operation.

[0117] In the following, Figures 4 to 6 show the test results as indicated below. The "Y" axis indicates the required cutting force in "kg", and the "X" axis indicates the number of cuts. The first comparative sample lot is indicated by the letter "A", the second comparative sample lot by the letter "B", and the third comparative sample lot by the letter "C". The first sample lot according to the first embodiment is indicated by the letter "D", the second sample lot according to the first embodiment is indicated by the letter "E", and the third sample lot according to the first embodiment is indicated by the letter "F". The fourth comparative sample lot is indicated by the letter "G". The fifth comparative sample lot is indicated by the letter "H".

[0118] Figure 4 shows a comparison of the cutting force of the first sample lot according to the first embodiment with the cutting forces of the first, second, and third comparative sample lots. As shown in Figure 4, the razor blade containing a lubricating layer with parylene-N (second comparative sample lot) has a small cutting force on the first cut, but the cutting force required to exceed the cutting force of the parylene-C coated blade (first comparative sample lot) increases with the number of cuts. On the other hand, the parylene-C coated blade (first comparative sample lot) requires a greater cutting force on the first use. The razor blade containing a lubricating layer with parylene-F (third comparative sample lot) consistently requires a greater cutting force compared to other parylenes.

[0119] The razor blade of the first sample lot (parylene C + parylene N) according to the first embodiment performed better than the first, second, and third comparative sample lots in all 10 cuts.

[0120] Figure 5 shows a comparison of the cutting force of a first sample lot according to the first embodiment and the cutting force of a second sample lot according to the first embodiment. As shown in Figure 5, the annealed razor blade has significantly less cutting force compared to the unannealed razor blade.

[0121] Figure 6 shows a comparison of the cutting force of the first sample lot according to the first embodiment and the cutting force of the third sample lot according to the first embodiment. As shown in Figure 6, the razor blade containing a capping layer containing titanium has significantly less cutting force compared to the razor blade containing a capping layer containing chromium.

[0122] Figure 7 shows a comparison of the cutting force of the third sample lot with that of the fourth comparison sample lot. As shown in Figure 7, razor blades containing a lubricating layer with parylene C + parylene N perform better than razor blades containing parylene-N as a lubricating coating.

[0123] Figure 8 shows a comparison of the cutting force of the second sample lot with that of the fifth comparison sample lot. As shown in Figure 8, razor blades containing a lubricating layer with parylene C + parylene N perform better than razor blades containing parylene-N as a lubricating coating.

[0124] manner Embodiment 1. A razor blade provided with a lubricating layer, wherein the lubricating layer contains parylene C and parylene N. Embodiment 2. The razor blade according to Embodiment 1, wherein the razor blade includes a tip edge, and the lubricating layer is provided on the tip edge. Embodiment 3. The razor blade according to Embodiment 1 or 2, wherein the razor blade is configured to be placed inside a razor cartridge. Embodiment 4. A razor blade according to any one of Embodiments 1 to 3, wherein the lubricating layer comprises a first layer and a second layer, the first layer comprising parylene C, and the second layer comprising parylene N. Embodiment 5. A razor blade according to any one of Embodiments 1 to 4, wherein an additional hard coating is provided on the razor blade, more specifically, the hard coating includes a ceramic, metal, and / or non-metallic coating. Embodiment 6. The razor blade according to Embodiment 5, wherein the ceramic comprises a boride and / or carbide, particularly titanium diboride or titanium, boron and carbon. Embodiment 7. The razor blade according to Embodiment 5 or 6, wherein the hard-coated metal contains chromium. Embodiment 8. A razor blade according to any one of Embodiments 5 to 7, wherein the non-metallic coating comprises diamond-like carbon. Embodiment 9. A razor blade according to any one of Embodiments 1 to 8, wherein a capping layer is further provided on the razor blade, and in particular the capping layer is positioned between the hard coating and the lubricating layer, and more specifically the capping layer contains a metal, and more specifically the capping layer contains chromium or titanium, and in particular the capping layer contains titanium. Embodiment 10. The razor blade according to Embodiment 9, wherein the lubricating layer is arranged on the capping layer, and in particular, the first layer is arranged on the capping layer and the second layer is arranged on the first layer. Embodiment 11. The razor blade according to Embodiment 9 or 10, wherein the capping layer has a thickness of about 5 nm to about 70 nm, more specifically about 10 nm to about 60 nm, and particularly about 20 nm to about 50 nm. Embodiment 12. A razor blade according to any one of Embodiments 1 to 11, wherein the lubricating layer has a thickness of about 0.005 μm to about 5 μm, more specifically about 0.02 μm to about 2 μm, and particularly about 0.1 μm to about 1 μm. Embodiment 13. A razor blade according to any one of Embodiments 1 to 12, wherein the lubricating layer does not contain pores, and in particular does not contain pores having a diameter of about 5 nm to about 200 nm. Embodiment 14. A razor blade according to any one of Embodiments 1 to 13, wherein the lubricating layer contains less than 1% by weight, more specifically less than 0.1% by weight of polytetrafluoroethylene, and is particularly free of or substantially free of polytetrafluoroethylene. Embodiment 15. The razor blade according to any one of Embodiments 5 to 14, wherein the razor blade includes an intermediate layer between the hard coating and the razor blade, the intermediate layer comprising a metal, more specifically niobium and / or titanium, and more specifically titanium, in particular metallic titanium. Embodiment 16. The intermediate layer is provided directly on the razor blade, Alternatively, the hard coating is provided directly on the razor blade according to any one of embodiments 5 to 15. Embodiment 17. A razor blade according to any one of Embodiments 1 to 16, wherein the razor blade contains a metal, particularly stainless steel, or is essentially made of a metal, particularly stainless steel, or is made of a metal, particularly stainless steel. Embodiment 18. A razor blade according to any one of Embodiments 2 to 17, wherein the cross-section of the tip edge has a substantially symmetrical tapered shape terminating at the cutting edge, the cross-section has a central longitudinal axis starting from the cutting edge, and the tip edge has a thickness of 1.5 μm to 2.4 μm measured at a distance of 5 μm from the cutting edge along the central longitudinal axis. Embodiment 19. A razor cartridge comprising at least one razor blade as described in any of Embodiments 1 to 18. Embodiment 20. A method for coating a razor blade, wherein the method is: - The razor blade is coated with parylene C, more specifically by chemical vapor deposition. A method comprising coating a razor blade with parylene N, more specifically by chemical vapor deposition. Embodiment 21. The method according to Embodiment 20, wherein the razor blade is coated with parylene C before the razor blade is coated with parylene N. Appearance 22. The method is, - The method according to embodiment 20 or 21, comprising coating the razor blade with titanium before coating the razor blade with parylene C and / or parylene N. Embodiment 23. Coating a razor blade with parylene C by chemical vapor deposition is - Sublimation of the parylene C precursor dimer, -In order to obtain the parylene C precursor monomer, the dimer of the sublimated parylene C precursor is thermally decomposed, - The method according to any one of embodiments 20 to 22, comprising depositing a parylene C precursor monomer onto a razor blade. Embodiment 24. The sublimation of the parylene C precursor dimer is carried out at a temperature of about 130°C to about 190°C, more specifically at a temperature of about 150°C to about 180°C, and / or The method according to embodiment 23, performed at a pressure of approximately 0.5 Torr to approximately 2 Torr, more specifically at a pressure of approximately 0.8 Torr to approximately 1.2 Torr. Apparatus 25. The thermal decomposition of the sublimated dimer of the parylene C precursor is carried out at a temperature of about 400°C to about 800°C, more specifically at a temperature of about 500°C to about 700°C, and / or The method according to embodiment 23 or 24, performed at a pressure of approximately 0.2 Torr to approximately 1 Torr, more specifically at a pressure of approximately 0.4 Torr to approximately 0.6 Torr. Embodiment 26. The method according to any one of Embodiments 23 to 25, wherein the deposition of the parylene C precursor monomer is carried out at a temperature of about 10°C to about 50°C, more specifically at a temperature of about 17°C to about 28°C, and / or at a pressure of about 0.01 Torr to about 0.5 Torr, more specifically at a pressure of about 0.05 Torr to about 0.2 Torr. Embodiment 27. Coating a razor blade with parylene N by chemical vapor deposition is - Sublimation of the parylene N precursor dimer, -In order to obtain the parylene N precursor monomer, the dimer of the sublimated parylene N precursor is thermally decomposed, - The method according to any one of embodiments 20 to 26, comprising depositing a parylene N precursor monomer onto a razor blade. Apparatus 28. Sublimation of the parylene N precursor dimer is performed at a temperature of approximately 130°C to approximately 190°C, more specifically at a temperature of approximately 150°C to approximately 180°C, and / or The method according to embodiment 27, performed at a pressure of approximately 0.5 Torr to approximately 2 Torr, more specifically at a pressure of approximately 0.8 Torr to approximately 1.2 Torr. Apparatus 29. The sublimated dimer of the parylene N precursor is thermally decomposed at a temperature of about 400°C to about 800°C, more specifically at a temperature of about 500°C to about 700°C, and / or The method according to embodiment 27 or 28, performed at a pressure of approximately 0.2 Torr to approximately 1 Torr, more specifically at a pressure of approximately 0.4 Torr to approximately 0.6 Torr. Embodiment 30. Deposition of parylene N precursor monomers is performed at a temperature of approximately 10°C to approximately 50°C, more specifically at a temperature of approximately 17°C to approximately 28°C, and / or The method according to any one of embodiments 27 to 29, performed at a pressure of approximately 0.01 Torr to approximately 0.5 Torr, more specifically at a pressure of approximately 0.05 Torr to approximately 0.2 Torr. Embodiment 31. The method according to any one of Embodiments 20 to 30, further comprising an annealing step, wherein the razor blade is annealed in an inert gas atmosphere at a temperature of about 300°C to about 400°C, more specifically at a temperature of about 330°C to about 370°C, particularly after the deposition of parylene C and / or parylene N. Embodiment 32. The method according to Embodiment 31, wherein the razor blade is annealed for a duration of approximately 10 seconds to approximately 20 minutes, more specifically for a duration of approximately 1 minute to approximately 5 minutes.

Claims

1. A razor blade having a lubricating layer, wherein the lubricating layer contains parylene C and parylene N.

2. The razor blade according to claim 1, wherein the razor blade includes a tip edge, and the lubricating layer is provided on the tip edge.

3. The razor blade according to claim 1 or 2, wherein the razor blade is configured to be placed inside a razor cartridge.

4. The razor blade according to any one of claims 1 to 3, wherein the lubricating layer comprises a first layer and a second layer, the first layer comprising parylene C, and the second layer comprising parylene N.

5. The razor blade according to any one of claims 1 to 4, further comprising a hard coating, more specifically, the hard coating comprising a ceramic, metallic, and / or non-metallic coating.

6. A razor blade according to any one of claims 1 to 5, wherein a capping layer is further provided on the razor blade, and in particular the capping layer is positioned between the hard coating and the lubricating layer, and more specifically the capping layer comprises a metal, and more specifically the capping layer comprises chromium or titanium, and in particular the capping layer comprises titanium.

7. The razor blade according to claim 6, wherein the capping layer has a thickness of about 5 nm to about 70 nm, more specifically about 10 nm to about 60 nm, and particularly about 20 nm to about 50 nm.

8. The razor blade according to any one of claims 1 to 7, wherein the lubricating layer has a thickness of about 0.005 μm to about 5 μm, more specifically about 0.02 μm to about 2 μm, and particularly about 0.01 μm to about 1 μm.

9. The razor blade according to any one of claims 1 to 8, wherein the lubricating layer does not contain pores, and in particular does not contain pores having a diameter of about 5 nm to about 200 nm.

10. The razor blade according to any one of claims 1 to 9, wherein the lubricating layer contains less than 1% by weight, more specifically less than 0.1% by weight of polytetrafluoroethylene, and in particular does not contain or substantially contains polytetrafluoroethylene.

11. The razor blade according to any one of claims 5 to 10, wherein the razor blade includes an intermediate layer between the hard coating and the razor blade, the intermediate layer comprising a metal, more specifically niobium and / or titanium, and even more specifically titanium, particularly metallic titanium.

12. The razor blade according to any one of claims 1 to 11, wherein the razor blade includes a metal, particularly stainless steel, or is essentially made of a metal, particularly stainless steel, or is made of a metal, particularly stainless steel.

13. The razor blade according to any one of claims 2 to 12, wherein the cross-section of the tip edge has a substantially symmetrical tapered shape terminating at the cutting edge, the cross-section has a central longitudinal axis starting from the cutting edge, and the tip edge has a thickness of 1.5 μm to 2.4 μm measured at a distance of 5 μm from the cutting edge along the central longitudinal axis.

14. A razor cartridge comprising at least one razor blade as described in any one of claims 1 to 13.

15. A method for coating a razor blade, wherein the method is - Coating the razor blade with parylene C, more specifically by chemical vapor deposition, A method comprising coating the razor blade with parylene N, more specifically by chemical vapor deposition.

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