JPH0265891A - razor for shaving - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to razors.

As used herein, a "razor" is defined as having at least one blade, a blade support, a protective surface attached to the blade support and extending outwardly from the support below the blade; A self-contained shaving device is defined as a self-contained shaving device having a cap that covers and protects the shaving device. The support and cap cooperate to maintain the blade in the desired shaving position. The razor may include a disposable handle and be a disposable razor in itself;
It may also take the form of a disposable cartridge for use with a permanent handle. On both sides, the disposable cartridge and the razor head of the disposable razor are substantially identical.

The blades used in modern shaving razors incorporate multiple features that work together to provide an effective and comfortable shaving action. Shaving razor blades are much sharper than ordinary industrial razor blades or knives. Sharpness is determined by [ultimate tip radius]
adius ) J and can be measured. Shaving razor blades typically have a local cutting edge radius of about 600 Å or less, whereas industrial razor blades, cutting knives, etc. typically have local cutting edge radii of several thousand degrees. Additionally, modern shaving razor blades have lubricant coatings on their cutting edges, such as carbon-fluoropolymer coatings.

The lubricant reduces the abrasive forces created by the engagement of the blade with the barb, thus greatly reducing the drag or "pull" experienced by the user during shaving.

To be considered satisfactory by modern standards, a shaving razor should remain usable for multiple shaves. The blade should maintain a sharp cutting edge, even when exposed to the effects of physical contact with beards and skin.
It should also retain the lubricant during these repeated shaves despite exposure to the chemical effects of water, soap, etc. encountered in the shaving environment. Razor blades for shaving must be suitable for efficient and economical mass production. It must withstand shipping, storage, and handling under normal conditions without special consideration. All of these factors together pose a formidable challenge.

A typical modern shaving razor consists of a stainless steel substrate, such as a martensitic stainless steel containing iron and hyflom, along with chromium or nitride superimposed on the stainless steel substrate at least along the cutting edge of the blade. Incorporates a hard chrome coating. A fluoropolymer lubricant, such as polytetrafluoroethylene, is applied and adhered to the hard coating. The hard coating can have a thickness on the order of several hundred amps.

Hard coatings are applied by a process known as sputtering. As discussed below, sputtering is typically performed under a controlled atmosphere, typically a rare gas at very low pressure. After the sputtering process, the semi-finished hard-coated blade is removed from the controlled atmosphere. applying a carbon-fluorine polymer dispersed in an evaporable liquid solvent, vaporizing the solvent, and then heating above the melting point of the polymer to weld any remaining lubricant;
Apply lubricant to the blade. Typically, the welding process is carried out in an inert atmosphere, but during the application of the dispersion lubricant,
and during any storage period between hard coating application and dispersion lubricant application, the blade is exposed to normal room air.

Razors incorporating blades of this overall configuration have heretofore been regarded as superior because they offer a clever combination of shaving performance, durability, and low cost. Still, there were demands for further improvements.

One avenue of research in the razor industry has been directed toward the development of hard coatings that can be used as a replacement for chrome in blades. The cutting edge of ordinary cutting tools gradually wears out, causing them to become dull (
and becomes unusable. This type of wear and tear is typically directly related to hardness. There are many materials that are harder than chrome. Ideally, all such hard materials could be tested. However, the cutting edge of a shaving razor typically does not become dull due to this type of wear and tear. The thin cutting edge on the very gun side of a razor blade usually becomes sluggish due to microscopic breakage of the cutting edge.Thus, in razor blades, hardness alone is not necessarily sufficient to determine the durability of the cutting edge. The wear resistance results achieved in other applications may not guarantee high durability of the cutting edge of razor blades.Moreover, the hard coatings used on razor blades may not be suitable for lubricant coatings. In particular, the lubricant must adhere well to the hard coating so as to provide a long-lasting lubricating effect during use. The adhesion of coating materials to lubricants is unpredictable. Many otherwise suitable hard coating materials are incompatible with lubricants in the sense that they do not adhere well to lubricants. For this reason, the search for better hard coatings for use in shaving razors has not been successful to date.

One aspect of the invention provides an improved shaving razor. The improved razor according to this aspect of the invention includes an improved blade. The blade includes a substrate and a layer of hard coating composition covering the substrate at least at the cutting edge of the blade and defining a local cutting edge of the cutting edge. Most desirably, the polymeric lubricant coating directly covers and adheres to the hard coating.

In the razor according to this aspect of the invention, the hard coating compound includes boron and carbon as boron carbide.

Desirably, at least a major portion of the hard coating compound is boron carbide. Pure boron carbide contains 80 atoms of boron and 20 atoms of carbon. Thus, the hard coating compound preferably contains at least about 40 atoms of boron and at least about 10 atoms of carbon, preferably at least about 60 atoms of boron and about 15 atoms of carbon;
More preferably, it contains at least about 72 atoms of boron and about 18 atoms of carbon.

The atomic ratio of boron and carbon in the hard coating is approximately 3:1 and 4.5:1.
Desirably, the ratio is between about 3:1 and about 4:1, and most preferably about 4:1.

The composition of the hard coating can include one or more additional metal or metalloid elements besides boron.

Preferably, such an additional element-containing coating consists essentially of boron carbide and the additional element.

Preferably, the additional element is selected from the group consisting of Si, Zr5Hf and combinations thereof, with Si being most preferred. The additional metal or metalloid element is desirably present in a minor proportion, such that the atomic ratio of boron to the additional metal or metalloid is at least about 5:1, and at least about 7:1.
and most preferably at least about 9:1. Preferably, the hard coating is substantially amorphous, ie, substantially devoid of crystalline structure discernible by X-ray crystallography.

It is desirable that the lubricant contains a fluorine-containing polyolefin. Particular preference is given to lubricants consisting essentially of polytetrafluoroethylene (PTFE). Preferably, the substrate comprises a ferrous alloy, such as stainless steel, containing iron and chromium. It is desirable that the hard coating be bonded directly onto the iron alloy.

Preferred razors according to this aspect of the invention provide excellent shaving performance. This excellent performance lasts for long periods of use. Although the present invention is not limited by any theory of operation, this combination of performance characteristics suggests that the superior durability of a cutting edge containing a hard coating is at least partially due to the bond between the hard coating and the overlying polymeric lubricant. This is the result of a combination of good interactions. This aspect of the invention therefore incorporates the discovery that boron carbide provides a long desired combination of physical properties and lubricant affinity. Another aspect of the invention provides a process for making a shaving razor and blade. The process according to this aspect of the invention desirably includes the steps of depositing a layer of a boron carbide coating compound on the cutting edge of the substrate by sputtering and depositing a polymeric lubricant, such as a fluorinated polyolefin, over the hard coating layer. a step of causing
and heat treating the substrate to which the hard coating layer and the lubricant are attached at a temperature approximately equal to or higher than the melting point of the lubricant.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

A blade according to an embodiment of the present invention includes a flat, strip-shaped substrate 10 . The substrate can include virtually any material commonly used in conventional razor blades. Among the materials,
Ferrous metals such as stainless steel are preferred. Among them, “4
Particularly preferred are martensitic stainless steels of the type referred to by the industry common name 00 series. These steels contain at least about 80% iron and at least about 10% iron.
Contains % chromium. substantially about 13-15% Cr;
Particularly preferred is 440A stainless steel with about 0.7% C and the balance Fe.

In the conventional manner, one cutting edge 15 cuts the substrate 10.
is provided on one side with a ground facet 11, a coarsely honed posterior facet 12, and a finely honed anterior facet 14. Opposite sides of the same cutting edge 15 of the substrate are provided with a finely honed anterior facet 16, a coarsely honed posterior facet 18 and a ground facet 19.

The front facets 14,16 intersect each other at the leading edge 20 of the cutting edge. The facets are formed by conventional processes such as grinding, honing, etc. The geometry of the facets is also the same as before,
It can be the same as that used for conventional chrome-coated stainless steel razor blade facets. Typically, the intersecting front facets of the substrate define a corner radius of about 300"A or less. In a double-edged blade, a second incisor 21 opposite said cutting edge 15 (FIG. ) are provided with facets of the same arrangement.

After the facets are formed, the blade is cleaned by a conventional wet-sanding process, which involves cleaning the blade in a suitable solvent solution to remove any debris or grease left as residue from the grinding or honing process. This may include washing.

After this pre-sizing step, the substrate 10 is subjected to a sputter-sealing step. Preferably, the substrates 10 are arranged in a stack 22
The faceted edges, or cutting edges 15.21, of the substrates in the stack are aligned with the long sides of the stack and extend parallel to each other.

The stack is placed in the chamber 24 of the sputtering apparatus.

Low atmospheric pressure, typically 10-10-6 mrxH'!
, a conventional vacuum pump system 26 is activated to depressurize the chamber, and the chamber is then filled with a noble gas such as argon to maintain the pressure within the chamber at approximately 10"-2 mm Kg. The conventional gas supply system 28 is then activated.The sputtering power supply 30 is then activated to apply an alternating current radio frequency (RF) voltage between the stack of substrates 10 and the chamber ground. The applied power density is
Based on the projected area of the long side of the stack, i.e. the area of the stack projected onto the plane defined by the cutting edge, approximately 0.1
~1, OW/7. AC voltage is room 2
An electric discharge is created in the low pressure gas in 4, converting the gas into a plasma, a mixture of positively charged ions and electrons. The well-known plasma "diode effect" places the stack of substrates 10 at a negative potential with respect to the plasma. Under the influence of this potential, positively charged ions from the plasma impinge on the exposed cutting edge 15.21 of the substrate. Alternatively, power supply 30 can be configured to provide a negative DC voltage to the substrate, with or without an alternating RF voltage. A direct current voltage similarly produces a discharge, which likewise causes bombardment of the substrate by ions from the plasma.

D C mat, - is used to remove material from the surfaces of facets 11-14, 16-19 by impinging ions by either RF sputter cleaning.

The removed substances, in the form of neutral atoms with high energy, either leave the chamber in the gas phase or are deposited on the walls of the chamber. This sputtering action removes trace contaminants from the surface of the substrate, particularly the facets. It is important to continue this sputter cleaning until the facet surface is free of contaminants. In particular, it is desirable to remove all traces of oxygen remaining on these surfaces in a sputtering process. Although stainless steel is typically considered an oxidation-resistant material, the surface of a stainless steel substrate--the first few layers of atoms that form an environment with the substrate--may be exposed to normal indoor ambient conditions. If so, it may contain significant proportions of absorbed oxygen, iron oxides, chromium oxides, or mixtures thereof. This sputtering step removes these first few layers of atoms, thus
Removes absorbed oxygen, oxides and other contaminants. The time required to achieve an acceptable degree of surface cleanliness varies depending on gas pressure, applied power, and physical configuration of the sputtering equipment. Typically, at least about 5 to about 50
For more than a minute, more typically from about 10 to about 30 minutes, the surface of the substrate facets is substantially free of free oxygen or oxygen in oxide form, and is also substantially free of other contaminants.

After the sputter coating step, the substrate 10 is subjected to a sputter coating step. During transitions in both of these steps, the substrate is maintained in a non-oxidizing atmosphere, such as a noble gas, reducing gas, or high vacuum. Typically, the sputter coating step is performed on the same equipment used for the sputter coating step;
The sputter coating step is performed immediately after the sputter coating step.

The sputter coating step is also performed using an atmosphere of a noble gas such as argon. Preferably, the sputter coating process is performed at an argon pressure of about 10-10 trmH'l;
Even more preferably, about 4 X 10-"vtrt H
'i argon pressure. During the sputter coating stage, the target 32 faces the cutting edge 15.21 of the stacked substrates. Each target 32 contains a material to be deposited as a hard coating on a substrate. To provide the required boron carbide-containing coating, each target 32 preferably has a ratio of about 3:1 to about 4.5:1, more preferably about 3:1 to about 4:1; and most preferably about 4:1. It is mainly composed of boron and carbon in an atomic ratio of 1. Boron and carbon are preferably present in the target as an alloy of boron and carbon, such as boron carbide. The target may also include additional Si, Zr, H
Non-boron metals or metalloids such as f i or combinations thereof may also be included.

Additional metals or metalloids can be present in the target as carbides. Additional materials in the target can be alloyed with boron and carbon or otherwise present as a separate part of the target.

Each target is held on a conventional target holder of the type commonly used in sputtering equipment. During sputter coating operations, the power supply 30 is activated to maintain the stack 22 of blades 10 at ground potential and to apply the RF mains voltage between the target 32 and the chamber wall. Again, the applied RF mains voltage generates an electrical discharge within the gas so as to convert the gas in the chamber into a plasma. Under the influence of the diode effect, the targets 32 assume a negative potential with respect to the plasma, so that positively charged ions from the plasma impinge on each target, dislodging material from the targets. A DC voltage can also be applied instead of or in conjunction with the RF mains voltage. Furthermore, the sputtering apparatus and techniques can use known sputtering means. For example, a magnetic field can be applied near the target to enhance sputtering through the known magnetron effect. Also, the stack of substrates and/or targets can be moved relative to each other to increase the homogeneity of the sputtering conditions along the length of each cutting edge.

The material splattering from the target 32 deposits on the substrate 10, and in particular on the exposed cutting edges 15.21, forming a coating that forms and adheres directly onto the ferrous material of the substrate. Material from the target is deposited as a substantially homogeneous amorphous coating. During the sputter coating step, the substrates 10 are stacked 2 as shown.
2, the sputtered atoms travel approximately from front to rear (from top to bottom in FIG. 1) with respect to each cutting edge of the substrate, and then collide with the substrate. The coating adheres approximately in the form shown in FIG. The opposite layer 38.40 is thus deposited on the opposite surface of each substrate 10 at the cutting edge 15.21. Layer 38 overlies facet 12.14 and layer 40 overlies facet 16.18. Each layer 38,40 projects forward beyond the leading edge of the blade 20 so that the two layers fuse together. The fused layers define the local cutting edge, or leading edge, of the cutting edge.

The hard coating on the second cutting edge 21 each time is substantially the same.

As used herein in reference to a hard coating overlying a substrate surface, the term "thickness" refers to the dimension perpendicular to the plane of the underlying surface. As shown, the thickness t of each hard coating layer 38,40 progressively decreases rearwardly away from the local cutting edge 42 of the cutting blade.

The average thickness of each hard coating layer 38.40 on the front facet 14.16 closest to the front facet 20 of the substrate is about 100 to about 4
0OA, more preferably about 150 to about 30OA, most preferably about 200 to about 25OA. The dimension between the tips, that is, the front-to-back dimension d between the frontmost localization 20 of the substrate and the frontmost localization 42 of the hard coating is preferably about 200~200.
Approximately 90OA.

More preferably about 300 to about 70 OA, most preferably about 500 to about 6 ooA. The average coating thickness t and tip-to-tip distance d both increase as the sputter coating process progresses.

The time required to deposit the hard coating material to the required coating thickness and tip-to-tip distance varies depending on the sputtering equipment geometry, gas pressure, and power applied from the power source. The factors that govern the deposition rates of various materials in typical sputtering processes are known to sputtering engineers, and the same factors apply to the sputter coating step of the present invention. Merely by way of example, higher sputtering input power tends to result in higher deposition rates; however, under typical circumstances, from about 1 to about 30 W/cI, based on the sputtered area of target 32.
! t, preferably about 5 to about 50 minutes, typically about 20 to about 50 minutes using an RF sputtering input power of about 6 W/i.
The coating process can be completed in about 40 minutes, most preferably about 30 minutes.

A sputtering process that deposits a coating of the desired thickness in a desired time generally does not cause overheating or other adverse effects on the substrate or coating.

If the facet surface is thoroughly cleaned during the sputtering step, the hard coating clings to the facet surface. Typically, no special sputtering techniques or steps need to be used to enhance this adhesion other than a thorough sputter cleaning step. As is known in sputtering technology, coating-to-substrate adhesion is enhanced by techniques such as ion implantation, in which a voltage is applied to the target during conventional sputtering techniques. is applied, a negative voltage is applied to the substrate, and some of the sputtered target material is ionized and accelerated towards the substrate. However, these additional techniques are generally unnecessary.

After the sputter coating step, the semi-finished blade containing the hard coated substrate is removed from the sputtering chamber. A polymeric lubricant is then deposited onto the blade, such as by dipping the blade in a dispersion of the polymer in an evaporable liquid carrier.

For example, conventional spraying can also spray the dispersion from a nozzle onto the exposed cutting edge 15.21 of the blade. Dipping and other conventional liquid application techniques may also be used as an alternative to spraying. If the polymer is in powder form, conventional powder application techniques can be used. The polymer deposition step and the storage and handling during hard coating and polymer deposition can be performed in a normal air atmosphere. After the polymer deposition step, the blade is heat treated in a conventional industrial furnace 48 equipped with a gas supply 50. Gas supply system 50 is operated to maintain a non-oxidizing atmosphere, such as a reducing or inert atmosphere, within the furnace during heat treatment. at a temperature at or above the melting point of the polymer, preferably at about the melting point temperature of the polymer, for a period of time sufficient to melt the lubricant and form a cohesive lubricating coating 52 over the hard coating 36. Perform heat treatment. The thickness of lubricant coating 52 varies depending on the amount of lubricant applied. Preferably, the amount of lubricant applied is the minimum amount required to form a cohesive coating on the portion of hard coating 36 covering the forward-most facet 14.16. Other areas of the blade may also be provided with a corresponding amount of lubricant, but this is not critical.

Preferably, the lubricant is a fluorine-free polyolefin, or a copolymer or blend containing a fluorine-free polyolefin. Thus, desirably, the lubricant comprises a polymer having a backbone consisting primarily of 10F2- repeating units. The lubricant preferably comprises polytetrafluoroethylene (PTFE), and most desirably consists essentially of PTFE. Desirably, the PTFE has a molecular weight of about 10,000 to about 30,000,000.

Relatively low molecular weight PTFE polymers, often referred to as telomers, are preferred. Approximately 10,00
0 to about 50,000. Particularly preferred is PTFE having a molecular weight of about 30,000. A suitable dispersion of 30,000 molecular weight PTFE in an evaporable fluorine-carbon solution was obtained from DuPont, Wilmington, P.A.
nt Company, Wilmington.

Registered trademark V from Delaware+ U, S, A-)
It is commercially available as YDAX1000. British ICI
Chemical Industries, Inc. (ICI Chemi)
calIndustries, Great Br1t
Other PTFE diffusion fluids are available under the trademark Fluon® from Ain. A relatively high molecular weight PTFE suitable for use in this process is commercially available from DuPont under the trademark Teflon®.

The melting point of PTFE is about 327°C, and when using PTFE, temperatures of about 327°C to about 335°C are desired for the heat treatment step.

As mentioned above, the deposited hard coating material defines the local cutting edge of the cutting blade. The sharpness of the cutting edge at this localized cutting edge is the radius of curvature of the hard coating surface at the cutting edge. It can be expressed by the local cutting edge radius R. Normally, local cutting edge radius R
is measured using a scanning electron microscope. Lubricant is not considered when measuring the radius of a local cutting edge. When used herein in reference to a lubricant-coated blade, the term "local cutting edge radius" should be understood to refer to the radius excluding the lubricant.

To form the completed razor, the blade 10 is assembled with the blade support 54 and cap 56 so that the blade 10 is between the blade support and the camp.

Blade support 54 defines a protective surface 58 extending outwardly from the support on the underside of cutting edge 15 of blade 10 and another protective surface 60 associated with cutting edge 21 . With traditional techniques, as in a typical disposable razor cartridge,
The cap and support can also be permanently attached to the blade. Alternatively, the blade may cooperate with a reusable cap and support, as in conventional "safety razors." Typically, the razor is provided with a handle 62, which can be integral with the blade support or removably coupled to the support.

The finished blade provides particularly desirable performance characteristics.

When the blade is new, the forces generated during sink cutting are generally less than comparable blades with other hard coating systems. Although the cutting force gradually increases with repeated use of the blade, this increase is less than that of a comparable blade with a conventional hard chrome coating.
The blade according to the invention tends to have less. These factors demonstrate that the blade according to the invention retains the sharpness of the cutting edge and also retains a strong bond between the lubricant and the hard coating.

The following non-limiting examples are intended to illustrate aspects of the invention.

Example I A strip of 440-A stainless steel is ground and honed to produce a patch of uncoated semi-finished blade or substrate. The grinding and honing process remains substantially uniform throughout the patch. Take two samples from the batch. Both samples undergo the same pre-washing or washing steps. Both samples are processed in the same sputtering equipment.

One sample, named the control sample, is approximately 10-3 mrs.
Sputter cleaning for 9 minutes under an argon pressure of Hg and an RF power density of about 0.1 W/cd. Following this sputter cleaning operation, the control sample was approximately 10-
Chromium is sputter coated for 30 minutes under an argon pressure of 3 Hg and a power density of about 3.0 W/ffl. The other sample, referred to as the test sample, is subjected to an 18 minute sputter sowing cycle using a PF power density of about 0.3 W/cn under an argon pressure of about 10 −3 mmHF. Following the sputter cleaning cycle, the test sample was approximately 1
Under an argon pressure of 0-3 mtxH'), approximately 6. O
Sputter coating is performed using a target made of boron carbide using a power density of W/crl.

After the sputter coating operation, sub-samples are taken from the control and test samples. These sub-samples, designated control no-lube and test no-lube, are set aside for later testing. X-ray diffraction and electron microscopy examination of test samples demonstrate that the coating is substantially amorphous and free of grain boundaries. The coating consists of boron and carbon in a 4:1 molar ratio. Vydax in the control sample and the rest of the test sample, respectively.
A dispersion of the LOOO fluoropolymer is sprayed under identical spray conditions followed by heat treatment at about 327° C. for about 10 minutes in a dry nitrogen atmosphere. The treated blades are named controlled lubrication and test lubrication.

Individual blades from each of the four populations are subjected to felt cutting force testing. This test measures the force required to advance the cutting edge of a blade at a given rate through a piece of felt with known physical properties.

This test is repeated using the same blade and a new piece of felt for each iteration. The results are shown in Table 1. In each case, the values represent the signal from the device's force transducer m
It is expressed in V (millivolts). This signal is proportional to the cutting force.

Table I Management without lubrication 43 49 65 87 Test without lubrication 41 40 42.5 42.
5 Controlled Lubrication fW 28.5 21.5 27.3 Untested Controlled Lubrication 22.6 18.4 21.0 The results for the untested Controlled Lubrication sample show evidence of cutting edge degradation typical of unlubricated blades. Cutting force averages approximately 1 per cut
Gradually increase at a rate of mV. By comparison, the increase in cutting force for the test unlubricated blade was only about 0.04 mV per cut. This increase is almost negligible and remains largely unaffected by the repeated exposure of the test blade's hard coating and the localized cutting edge defined by the hard coating to the harsh conditions of the felt cutting test. It is shown that.

The results for the two groups of lubricated blades show that the cutting force typically decreases during the first few cuts. After this decrease,
The control sample results show a significant gradual increase between the 5th and 200th cuts, with an average slope of approximately 0.39 mV/1 cut. The test sample also shows an increase, but the average increase is smaller, only increasing by about 0.17 mV per cut from the 5th to the 200th cut. This indicates that the adhesion between the hard coating and lubricating coating of the test sample was less than or equal to that of the control sample.

Example 1 The procedure of Example 1 is repeated under the same conditions, except that the sputtering target of the test group contains approximately 5 atoms of silicon, 76 atoms of boron, and 19 atoms of carbon. The results are approximately equal to the values shown in the first example.

Many modifications and combinations of the features described above may be used without departing from the invention.

Merely by way of example, the invention can also be applied in connection with a single-edged blade rather than the double-edged blade described above.

Accordingly, the above description of the preferred embodiments is to be construed as illustrative rather than as limiting of the invention as defined in the claims.

[Brief explanation of the drawing]

1 is an illustrative idealized partial cross-section of a blade according to an embodiment of the invention; FIG. 2 is an explanatory diagram showing the steps of a process according to an embodiment of the invention; FIG. 10... Substrate, 15... Cutting blade, 38.40.
・・・Hard film layer, 52...4 people outside the lubricant layer

Claims (1)

[Scope of Claims] 1. A shaving razor including a blade support, a cap, and a blade having a cutting edge, the blade including a substrate and at least the cutting edge covering the substrate. , at least one layer of a hard coating compound containing boron and carbon as boron carbide;
a polymeric lubricant that directly covers and adheres to the hard coating compound. 2. The razor of claim 1, wherein the hard coating compound comprises at least about 40 atomic percent boron and at least about 10 atomic percent carbon. 3. The hard coating compound comprises at least about 60 atomic percent boron and at least about 15 atomic percent carbon.
Razor mentioned. 4. The hard coating compound comprises at least about 72 atomic percent boron and at least about 18 atomic percent carbon.
Razor mentioned. 5. The razor of claim 2, wherein said hard coating compound is substantially boron carbide. 6. The razor of claim 1, wherein the hard coating compound further includes at least one non-boron metal or metalloid element. 7. The razor of claim 6, wherein said hard coating compound consists essentially of boron carbide and said at least one non-boron metal or metalloid element. 8. The razor of claim 7, wherein the at least one non-boron metal or metalloid element is selected from the group consisting of Si, Zr, Hf and combinations thereof. 9. The razor according to claim 8, wherein the at least one metalloid element is Si. 10. The razor of claim 8, wherein the atomic ratio of boron to the at least one non-boron metal or metalloid element is at least about 9:1. 11. The razor of claim 1, wherein the hard coating compound within the layer is substantially amorphous. 12. The razor of claim 1, wherein the substrate includes a ferrous alloy, and the hard coating directly covers and adheres to the ferrous alloy. 13. The razor of claim 12, wherein the iron-based alloy includes at least about 10% chromium and at least about 80% iron. 14. The lubricant includes a fluorine-containing polyolefin.
A razor according to claim 1. 15. The razor according to claim 14, wherein the fluorine-containing polyolefin is polytetrafluoroethylene. 16. The razor of claim 15, wherein said lubricant consists essentially of polytetrafluoroethylene. 17. The razor of claim 1, wherein the interface between the layer of hard coating compound and the substrate is substantially oxygen-free. 18. said cutting edge includes a pair of back-to-back facing forward facets on said substrate, said facets intersecting each other to define a forward-most edge of said substrate;
The layers include one layer on each of the front facets, and the layers of the hard coating compound on the front facets fuse together and project forwardly from the forward-most edge of the substrate, so that:
the hard coating compound forms a localized cutting edge of the incisor;
A razor according to claim 1. 19. The razor of claim 1, wherein the cutting edge has a local cutting edge radius of about 500 Å or less. 20, each of the layers on the anterior facet has a thickness of about 200
20. The razor of claim 19, wherein the razor is about 900 Å. 21. a. providing a substrate with a cutting edge; b. depositing at least one layer of a hard coating compound containing boron and carbon as boron carbide onto the cutting edge of the substrate; c. A polymeric lubricant is deposited over the layer of hard coating compound, and the substrate with the hard coating and lubricant deposited is coated with at least substantially the same layer of the lubricant, such that the lubricant is deposited onto the hard coating compound. A method of making a shaving razor, comprising: heat treating at a high temperature equal to the melting point temperature. 22. The hard coating compound comprises at least about 40 atomic percent boron and at least about 10 atomic percent carbon.
The method described in 1. 23. The lubricant includes a fluorine-containing polyolefin.
23. The method according to claim 22. 24. The method of claim 22, wherein said step of depositing said polymer is performed in an atmosphere of air.