CA2111343C - Improvements in or relating to razor blades - Google Patents
Improvements in or relating to razor bladesInfo
- Publication number
- CA2111343C CA2111343C CA002111343A CA2111343A CA2111343C CA 2111343 C CA2111343 C CA 2111343C CA 002111343 A CA002111343 A CA 002111343A CA 2111343 A CA2111343 A CA 2111343A CA 2111343 C CA2111343 C CA 2111343C
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- CA
- Canada
- Prior art keywords
- diamond
- substrate
- layer
- less
- edge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26B—HAND-HELD CUTTING TOOLS NOT OTHERWISE PROVIDED FOR
- B26B21/00—Razors of the open or knife type; Safety razors or other shaving implements of the planing type; Hair-trimming devices involving a razor-blade; Equipment therefor
- B26B21/54—Razor-blades
- B26B21/58—Razor-blades characterised by the material
- B26B21/60—Razor-blades characterised by the material by the coating material
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- Forests & Forestry (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physical Vapour Deposition (AREA)
- Dry Shavers And Clippers (AREA)
- Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
- Light Guides In General And Applications Therefor (AREA)
- Polishing Bodies And Polishing Tools (AREA)
- Cutting Tools, Boring Holders, And Turrets (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Knives (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Cosmetics (AREA)
Abstract
A razor blade includes a substrate (50) with a wedge-shaped edge at a distance of forty micrometers from the sharpened tip (52), and a layer of diamond or diamond-like material (60) defined by facets (66, 68) that have an included angle of less than seventeen degrees that has a thickness of at least twelve hundred angstroms from the sharpened tip (52) of said substrate (50) to a distance of forty micrometer from the sharpened tip (52), and an ultimate tip defined by facets (62, 64) that have lengths of at least about 0.1 micrometer and define an included angle of at least sixty degrees, and that defines a tip radius of less than about 400 angstroms, an aspect ratio in the range of 1:1-3:1, a hardness of at least thirteen gigapascals and an L5 wet wool felt cutter force of less than 0.8 kilogram.
Description
~093/00204 2 ~ PCT/US92/04932 IMPROVEMENTS IN OR REL~TING TO RAZOR BLA~S
This invention relates to improved raxurs and razor blades and to procrsrer for producing razor :~
blades or similar cutting tools with sharp and durable cutting edge~. A razor blade typically is formed of a suitable substrate material such as metal or ceramic and an edge is formed with wedge-shape configurat~on with an ulti~ate edge or tip that has a radius of le88 than about 1,000 angstroms. ~uring u e, a razor blade ic h~ld in,the razor at an angle o~ approximately 25 , and wi~h the wedge-shaped edge in contact with the skin, it i~ ~oved o~er the ~ace ~o that wh~ the ~dge ~nco~nter~ a beard hair, it enters and severs it by p~u~essi~e penetration, aided by a wedging action. It i~ believed th~t the cut portion of the hair ~which on average is about 100 micromet~r~ in dia~eter) re~i n~ pre~ed in contact wit~ the blade facets re~ote fro~ the facial ~kin sur~ace for a penetration up to only about h~lf 2 0 the hair dia~e~er. Beyond thi~, th~ hair can band and contract away fro~ th~ bl~d~ to reliQ~e th~
; wQdgin~ forc~ he rQ~istanG~ to pQn~tration through reaction b~tw~n hair and blade fac~t~
therQfore occur~ only ov~r about thQ first sixt~
~icrometar~ o~ the ~lad~ tip back ~rom th~ ~dge and th8 g~ometry of th~ blade tip in thi~ reqion i8 regarded a~ b~ing the most impoxtant from the cutting point o~ ~i8W~
It i~ b~liQved ~hat a raduction in the 1 3 -1 ~
W O 93/00204 PC~r/US92/04932 included angle of the facets would correspondingly reduce the resistance to continued penetration of the blade tip into the hair. However, when the included angle is reduced too much, the strength of the blade 5 tip is inadequate to withstand the resultant bending :
forces on the edge during the cutting process and the tip deforms plastically (or fractures in a brittle ~:
fashion, dependent on the mech~ical properties of :-the material from which it is made) and so sustains permanent damage, which impairQ its ~h-~uent cutting performance, i.e. the edge bscome6 "bluntH or ~dull". As shaving action is severe and blade edge damage fr~ently results, and:to e~hAnce shavability, the use of one or more layers of :~
supplemental coating material has been proposed for shave facilitation, and/or to increase the harAn~c, strength and/or corrosion resi~tance of the shaving edge. A number of such coating materials have been A~ such a~ polymeric ~aterials, metals and alloy~, a~ well a~ other materials including diamond and diamond-like carbon (DLC) ~aterial. ~iamond and diamond-like carbon (DLC) ~aterials may be characterizQd a~ ha~ing ~ubstantial ~p3 carbon h~n~ g; a ~al~8 den ity gr~ater than 1.5 grams/cm3;
and a Raman peak at about 1331 cm-l (dia~ond) or about 1550 cm 1 (DLC). Each ~uch layer or layers of ~upplQ~ental ~aterial desirably provides chAract~ristic~ ~uch as i~proYod ~havsbility, i~prov~d hardnes~,~edge str~ngth and/or corro~ion re~istance while not adver ely a~f~cting the geometry and cutting effectivenes~ of the ~having odge.
In ac~o~dance with one a~pect of the invention, ther i-~provid-d a razor blade compri~ing a~ub~trat~ w1th a:: dge- b~p d ~dg- with a ~harp~ned tip~and;an i w lud d fac-t angl- in th~ rangQ of 10--~- 17- in th- region froa forty to one h~d~ed ~icro~eter~ fron th~ ~ub~trate tip, and a lay~r of w093t002~ ~ 3 PCT/US92/04932 strengthening material on the wedge-shaped edge that is preferably at least twice as hard as the underlying substrate, and has a thickness of at leas~
about twelve hundred angstroms from the tip of the substrate to a distance of forty micrometers from the substrate tip, defines a tip of radiuc of less than about 400 angstroms and that is defined by tip facets with an included angle of at least 60-, and has an asp~ct ratio in the range of 1:1-3:1. The blade ~Yhihits excellent shaving properties and long shaving life.
In particular embodiments, the razor blade sub~trat~ i8 steel; the wedge-shap~d adge is formed by a ~ once of ~e~h~nical abrading steps; a layer of diamond-like carbon material i~ formed by sputtering material from a target of high purity graphite ~n~ ently with the application of an RF
bias to the steel substrate, the DLC layer has a har~n~cs of at least thirteen gi~p~c~ls; and the blade edge ha~ excellent edge strength a~ evidPn~e~
by an L5 wet wool felt cutter force of 1~ ~ than 0.8 kilogram, and n~gligibl~ dry wool felt cutter edge damage (la88 ~han ~ifty small da~age regions (each such s~all daEage region being o~ la~ than tw~nty ~icro~eter di~ension and le88 than ten microm~t~r depth) and no da~age regions of larger dimen6ion or d~pth) ~ ~icroscop~cally A~
In 2ccor~-~c~ wi~h anoth~r asp~ct of the invention, ~h~re i~ pr~vided a ~a~a~ for for~ing a razor blad~ that inolude~ the steps of providing a sub~trat~, for~ing on an adg~ o~ th~ sub~trat~ ~
wed~3 -~p~d sharpenQd ~dge that ha~ an included angle of le~- than thirty da~aa~ and a tip radiu~
(i~e~ th~ ~stioat~d radius of th~ larg-r c~rcl~ that ~ay be po8itioned within the ult~ate tip of the edge when ~u¢h ulti~ate tip is vi~w~d under a ~c~nning electron ~i¢roscope at magnification~ of at leas~
W O 93/00204 PC~r/US92/04932 ;
25,000) of less than twelve hundred angstroms; and ~
depositing a layer of strengthening material on the .
wedge-shaped edge of the substrate while an RF bias is applied to the substrate to provide an aspect 5 ratio in the range of 1:1 - 3:1, and a radius at the ~
ultimate tip of the strengthening material of less ~;
than about five hul.dled al.~aL~oms.
In a particular process, the substrate is ;
mech~nically abraded in a sequence of honing steps to form the sharpened edge: layer~ of an interlayer material and diamond or diamond-like material are successiv-ly ~pQcited by sputtering; the layer of interlayer material having a thic~nq~ of 1e85 than -~
about five h-lnAred ang~troms, and the diamond or DLC
coating having a thickness of at least about twelve h~ e~ a..~.oms with an ultimate tip that i5 defined by tip facets with an included angle of at l~ast 60-; the layer of diamond having a Raman peak at about 1331 c~-l and the layer of diamond-like carbon (DLC) material having a Raman peak at about -~ lS50 cm~l; 8 ~ ~tantial sp3 carbon honAi~; and à
ma~s density grQater than 1.5 grams/cm3; and an adherent polymer coating is applied on the dia~ond or DLC coated cutting edge.
In accor~n~e with another aspect of the in~ention~ there is provided a shaving unit that comprise~ blade 8upport structure that ha~ ~xternal ~urface~ for onq~ging u~r ~kin ah~ 3 and rearwardly of the blad~ ~dge or edg~ and at l~a~t one blade 3Q meD~er securQd to the 8upport structur~ . The ra~or blad~ structure secured to th~ ort stru~L~
include~ ~ substrate with a w~e-~~aped cutting edge dsrined by ~-c t~ th~t~have ~n ~ncluded angle of less th~n ~-v-nt--n~d gr--s at a di-tance of forty : 35 ~icro~ ter- fro~ th~ ~harpened tip, ~nd a l~yer of ~trength-ning -at-rial on the wQdge-~haped cutting edgQ that has a thickness of ~t le~st twelve 1.UndL ed W093/00204 2 ~5 13~1u PCT/uS92/04s32 angstroms from the sharpened tip of the substrate to a distance of forty micrometers from the sharpened tip, and an ultimate tip defined by facets that have lengths of at least about 0.1 micrometer and define an included angle of at least sixty degrees, a radius at the ultimate tip of the strengthening material of les~ than 400 angstroms and an aspect ratio in the range of 1:1-3:1.
In a particular shaving unit, the razor blade ~tructure includes two steel sub~trate~, the wed~a ~ped edges are Ai ~p~-6~ parallel to one another between the skin-engaging ~urfaces; a layer of interlayer material is between the steel substrate and the edge ~-L~ he~in~ layer and is of diamond or 15 DLC material; each layer of interlayer material has a -~
thicknes- of le~s than about five hundred a..~aoms;
each di~ond or DLC coating has a thicknes~ of at lea~t about twelve hundred angstrom~: ~ub~tantial sp3 carbon ~on~n~; a ma~fi density greater than 1.5 gra~/cm3; and a Raman peak at about 1331 ~-1 ' tdiamond) or about 1550 cm~l (D ~); and an adherent polyuer coating i8 on each layer of dia~ond or diamond-like carbon ~aterial.
The ~having unit ~ay be oP the dispo~able 25 c~rtridge typ~ adapted for coupling to and ~ncu~rling -~
fro~ a razor h~nAle or ~ay be integral with a ~Ale 80 th~t the co~plete razor i~ ~scArded as a unit wh~n tha blade or blades b~co~e dull. The front and re~r ~ki.l L..~ging surface~ cooparat~ with the blade 30j edge (or edge~) to define the sha~iny g~ometry.
P~r~c~ rly preferred ~having unita are Or the types ahown in U.S. Patent 3,876,563 and in U.S. Patent 4,586,2~S.
0th r fe~tur ~ and advantagea of ths 3S inv ntion wlIl b- - n aa th~ following d acription 0~ pa~ r Q~bodi~ent~ ~c~lasse~, in con~unction with tho drawing-, in which: -w 1 ~
W093/0~2~ PCT/US92/04932 Fig. 1 is a perspective view of a shaving unit in accordance with the invention;
Fig. 2 is a perspective view of another shaving unit in accordance with the invention;
Fig. 3 is a diagrammatic view illustrating one example of razor blade edge geometry in accordance with the invention;
Fig. 4 is a di~grammatic view of apparatus for th~ practice of the invention; and Figs. 5 and 6 are Raman ~pectra o~ DLC
material ~er~itad with the apparatus of Fig. 4.
DescriDtion of Particular ~hodi~ts ~ With reference to Fig. 1, shaving unit 10 includes structure for attachment to a razor hAnAle, and a platfor~ member 12 molded of high-impact poly~y,ene that includes structure defining forward, trangversely-ex~n~in~ ~kin engaging ~urface 14.
Mounted on platfsr~ m~mber 12 ar~ le~tng blade 16 h~ving sharp~.ne~ ~dge 18 and following blade 20 having sharpened ed~ 22. Cap ~e~ber 24 of molded high-i~pact poly~y~ene ha~ structure defining ~kin-engaging surf~ce 76 that is di~ rearwardly of blade edge 22, and affixed to cap ~e~ber 24 is shaving aid co~po~ite 28.
2 5 The shaving unit 30 ~hown in Fig. 2 is of ~he typ~ ~ho~n in J~h~n U. S. Patent 4,586,255 and includQ~ molded body 32 with f ront portion 34 and r~ar portion 36. R~ ntly ~Qcur~d in body 32 ~r~
guard ~ember 38, l~Ain~ blada unit 40 ~nd trailing blade unit 42. Each blad~ unit 40, 42 înclud~ a blade me~bQr 44 that has a sharp~n~ ~dg~ 46. A
shaving ~id compo8it~ 48 i~ frictionally ~ecurad in a r~.er- in ro~r port;ion 36.
A diagra~atic vi~w of the adge region o~
the blade6 16, 20 and 44 is showrs in Pig. 3. Tha blade includQ~ stainlea~ steel body por~ion 50 with a w~dge-shaped ~harFon~A edge for~ed in a seq~nce of W O 93/00204 ~ ~ t~ 3 PC~r/US92104932 edge forming honing operations that forms a tip portion 52 that has a radius typically less than 500 -angstroms with facets 54 and 56 that diverge at an angle of about 13-. Deposited on tip 52 and facets 54, 56 is interlayer 58 of molybdenum that has a thickness of about 300 angstroms. Deposited on molyhAen~m interlayer 58 is outer layer 60 of diamond-like carbon (DLC) that has a thic~se of about 2,000 a~gstroms, with facets 62, 64 that have lengths of about one-quarter micrometer each and d~fine an includ~d angle of about 80-, facets 62, 64 merging with main facet surfaces 66, 68 that are i spo~~A at an included angle of about 13- and an aspect ratio (the ratio of the distance (a) from DLC
tip 70 to stainless steel tip 52 and the width tb) of the DLC coating 60 at tip 52) of about 1.7.
Depo~ited on layer 60 i~ an adhQrent telomer lay~r 72 that has a ~ubstantial a~ depo6ited thickn~s but is reduced to monolayer thickne-s during initia}
shaving.
Arr~ratus for p~ ing blades o~ the type shown in Fig. 3 i~ diagra~matically illu~trated in Fig. 4. That apparatue includes a DC planar ~agnetron sputtering syste~ manufactured by Vac Tec Sy~t~m~ o~ Boulder, Coloxado that has stainless steel chamb~r 74 with wall ~tructure 80, door 82 and base ~tructure 84 in which i~ for~Qd port 86 couplsd to a 8uit:abl~ vacuu~ ~y~te~ (not ~hown). Mount~d in cha~b~r 74 is carousel support 88 with upg~n~
~ ~rt ~emb~r 90 on which i~ ~~,F-?~ a ~tack o~
razor blade- 92 witb th~ir sharpQn~d ~dgQs 94 in align~nt and faclng outwardly fro~ ~upport 90. Also d~po~od in ch~ber 7~ ar- ~upport ~tructur~ 76 for targ t ~ -b r 96 of ~olybd-nu~ (99.99% purQ) and ~upport ~tructure 78 for ~arg~t a~b~r 98 of graphite (99.999~ pur-). Target~ 96 and 98 are vertically di~pos~d plat~, each about twelve c~nti~Qter~ wide t3 and about thirty-seven centimeters long. Support structures 76, 78 and 88 are electrically isolated from chamber 74 and electrical connections are provided to connect blade stack 92 to RF power supply 100 through switch 102 and to DC power supply 104 through switch 106; and targets 96 and 98 are connected through switches 108, 110, respectively, to DC magnetron power supply 112. Shutter structures 114 and 116 are disposed adjacent targets 96, 98, respectively, for movement between an open position and a position oh~~lring its adjacent target.
Carousel 88 supports the blade stack 92 with the blade edges 94 spaced about seven centimeters from the opposed target plate 96, 98 and is rotatable about a vertical axis between a first position in which blade stack 92 iS in opposed alignment with molybdenum target 96 (Fig. 4) and a ~con~ position in which blade stack 92 i5 in opror~
alignment with graphite target 98.
In a particular processing sequence, a stack of blades 92 (thirty centimeterC high) is ~ecured on ~prQrt 90 (togethQr with three polished stainl~ss steel blade bodiQs di~ parallel to the target); chamber 74 is evacuated; the targets 96, 98 25 are cleaned by DC sputtering for five minutes; switch 102 i8 then closed and the blades 92 are RF cleaned in an argon environment for three minutes at a pr~ssure of ten millitorr, an argon flow of 200 sccm and a power of 1.5 kilowatts; the argon flow i~ then r~ e~ to 150 sccm at a pressure of 4.5 millitorr in chamber 74; switch 106 is clo~ed to apply a DC bia~
of -50 volts on blade~ 92; switch 108 i~ clo~ed to sputter target 96 at one kilowatt power; and shutter 114 in front of molybdenum target 96 is opened; for 35 twenty-eight seconds to deposit a molybdenum layer 58 of about 300 angstroms thicknQss on the blade edges 94. Shutter 114 is then closed, switches 106 and 108 W O 93~00204 21 L1~ 3 Pc~r/us92/o4932 are opened, and carousel 8~ is rotated so to ~:
juxtapose blade stack 92 with graphite target 98.
Pressure in chamber 74 is reduced to two mil~itorr with an argon flow of 150 sccm; switch llo is closed ;~
to sputter graphite target 98 at 500 watts; switch 102 is closed to apply a 13.56 MH~ RF bias of one thousand watts (-440 volts DC self bias voltage) on blades 92, and concurrently shutter 116 is opened for twenty minuteC to deposit a DLC layer 60 of about two ~o~ angstroms thickness on molyhA~n~lm layer 58.
The DLC coating 60 had a radiu~ at tip 70 of about 250 Angstrom~ that is defined by facets 62, 64 that . have an included angle of about 80-, an aspect ratio of about 1.7:1, and a hardnes~ (as measured on the planar surface of an adjacent stainless steel blade body with a Nanoindenter X instrument to a depth of five hl~Ared angstroms) of about se~enteen ~.
gi~ra~CAls (the stainless steel blade body having a har~esc of about eight gi~ ls). A~ illustrated in Fig. 5, Ra~an spectroscopy of the coatin~ mat~rial 60 A~p~Cit~d in thi~ pr~c~r- show~ a broad Raman peak 120 at about 1400-1500 c~-l wave nu~ber, a ~pectrum typical of DLC ~tructure.
A coating 72 of polytetrafluoroethylene telo~er is then applied to the ~LC-coated edges of ~h~ blad~. The process inYolve~ heating th~ blades in a neutral at~osphere of argon and pro~iding on the cutting c~9~ o~ th~ blade~ an adher~nt and friction r~ducing poly~r coating of ~olid PTF~. Coating~ 58 and 60 w~r~ firmly adhersnt ~o thQ blade body 50 and provided low wet wool felt cutter force (the lowest of the fir~t fiv~ cuts with wet wool felt (L5) baing about 0.45 kilogram), and with~tood repaated applicationfi of wet wool felt cutter forces (the low-~t cutter forc~ of the 496-500 cuts b~ng about 0.65 kilograa), indicating that the DLC coating 60 is sub~tantially unaffected by exposure to the sev~re W093/00204 ~ 1 1 ~ 3 ~ ~ pcT/uss2/o4932 -- 10 -- ,, conditions of this felt cutter test and remains firmly adhered to the blade body 50. Edge damage and delamination after ten cuts with dry wool felt as determined by microscopic assessment was 5 substantially less than commercial chrome-platinum -~
coated blades, there being less than four small edge damage regions (each such small damage region being of less than twenty micrometer dimension and less than ten micrometer depth) and no damage regions of larger dimencion or depth. Resulting blade elements 44 were as~emblQd in cartridge units 30 of the type shown in Fig. 2 and shaved with excellent shaving reQultQ.
In another particular proce~ing sequence, a stack of blade~ 92 (thirty centi~eters~high) is secured on ~upport 90 (together with three polished stainle~ st-el blade bodies ~; ~ro~ parallel to the target); cha~b~r 74 is evacuat~d; the targets 96, 98 are cleaned by DC ~LLering-for five ~inute~; switch 102 is th~n clo~Qd and the blade~ 92 are RF cleaned in an argon e m ironment for two and a quarter ~inutes at a pres~ure of t~n ~illltorr, an argon flow of 200 sccm and a power of 1.5 kilowatts, the argon flow i5 then re~c~ to 150 8CC~ at a pre~sure of six millit~rr in cha~ber 74; switch 106 i~ closed to apply a DC bia~ of -S0 volt~ on blad~ 92; shutter 114 in ~ront of ~olybd2nu~ target 96 i8 opened; and ~witch 108 i~ clo~Qd to ~putt-r target 96 at on~
kilowatt povQr for thirty-two ~snA~ to ~po~it a molyhA~n~ layer 58 of about 300 angstro~ thickn~s on the blade odgQ~ 94, Shutter 114 i~ then clo~d, ~witch-~ 106 and 108 are op-n-d, and carou~ol 88 i~ ~
rotatod 90- to ~uxtapo-~ blad ~t~ck 92 with graphite ; t~rg t 98:. ~P~r ~ur in:ch b r 7~ i- roduced to two ~lllltorr w1th un ~rgon flow of 150 ~cc~$ ~witch 110 i~ clo~ed to~putt r graphit~ target 98 at 500 watts;
~ ~w1tch ~02 i- clo~Qd to ~pp~ly a 13.S6 MHz RF bia~ of ,:
~ ' 13.4~",2 W O 93/00204 PC~r/U$92/04932 320 watts (-220 volts DC self bias voltage) on blades 92, and concurrently shutter 116 is opened for seven minutes to deposit a DLC layer 60 of about 900 angstroms thickness on molybdenum layer 58. The DLC
coating 60 had a tip radius of about 300 Angstroms, an aspect ratio of 1.6:1, and a hardness (as measured on the planar surface of an sdjacent stainless steel blade body as measured with a Nanoindenter X
instrument) of about thirteen gi~p~c~ls.
A coating 72 of polyt~trafluoroethyle.ne telomer is then applied to the D~C-coat~d edge~ of the blades in accordance with the teaching of U.S.
Patent No. 3,518,110. The process involved heating the blades in a neutral ~t~osphere of argon and 1~ providing on the cutting edges of th~ blades an adherent and friction-reducing polymer coating o~
solid PTFE. Coating~ 58 and 60 w~re firmly adherent to ~he blade body 50, provided low wet wool felt cutter force (the lowest of the ~irst five cut~ with wet ~ool felt (L5) being about 0.6 kilogram), and with~tood repeated applications of w~t wool folt cutter forc~ (the l~we~t cutter force of the 496-500 cuts being about 0.76 kilogr~, indicating that the DLC coating 6~ is substantlally unaf~Qct~d by ~ re ts:~ the savere condition o~ thlB f~lt cutter test and r~ain~ firmly adher~d to th~ ~lade body 50.
Edge da~age and dela~ination after t~n cuts with dry wool felt ~s d~t~r~ined by ~icro~copic A-~ersment was substaintially ~ 8 than com~ercial chrome-plat~nu~
coat~d bl~ , there h~~n~ lfi~ ~han four ~mall edge . damag~ region~ ch ~uch ~all da~aqe region being of le8~ than tw~nty ~icro~ter di~en~ion and 1~
than ton ~icro~ster d~pth~ and no da~ag~ region~ of larg~r dimen~on or d~pth. ~o~tting 1~ 9 el~ments 44 wer~ a~QEbl~d in cartridg~ ~nit8 30 of tbe ~ype shown in Fig. 2 and ~ha~ed with ~xcellent ~having result~.
W093/002~ 2 ~ 1 1 3 1 ~ PCT/US92/04~32 In another processing sequence, chamber 74 is evacuated; the targets 96, 98 are cleaned by DC
sputtering for five minutes; switch 102 is then closed and the blades 92 are RF cleaned in an argon environment for two and a quarter minutes at a pressure of ten millitorr, an argon flow of 200 sccm and a power of 1.5 kilowatts; the argon flow is then r~ d to 150 sccm at a pres~ure of six millitorr in chamber 74; switch 106 is closed to apply a DC bias of -50 volts on blades 92; shutter 114 in front of moly M enum target 96 is opened; and switch 108 is closed to sputter target 96 at one kilowatt power for thirty-two ~eco~A~ to deposit a DolyhA~nl~m Iayer 58 of abou~ 300 ang troms thir~ne-- on the blade edges 94. Shutter 114 is then closed, switches 106 and 108 are opened, a~nd:carousel 88 is rotated 90- to juxtArore blade stack 92 with graphite target 98.
Pre~ ~e in chamber 74 is re~ to two millitorr :~
wi:th an argon rlOw of 150 scGm; switch 110 is closed to sputter graphite target 98 at 500 watts: switch 102 is closod to apply a 13.~56 ~Hz RF bias of 320 watt~ ~-220 volts DC self bi~s voltage) on blades 92, : and ron~rrently shutter 116 i~ opened for five minute~ to ~e~o~it a D~C layer 60 of abou~ 600 a..~ oms thic~ç~ on ~olyhAen~l~ layer 58. The DLC
coating 60 had a tip radiufi of about 400 Angstro~s, an ~pect ratio of 1.7:1, and a hardnes~ (as ~easured on tb- plan~r ~urfac~ of ~n adjac~nt ~tainl~ te~l blade body as ~oasured with ~ Nanoln~nter X
in~trumont) of about thirteon gig~pa~cals. A8 -illu~trated in Fig. 6, Ra~an ~pectroscopy of the coating ~aterial 60 A~po~ited in thi~ PL~r- ~hows a broad Raman peak 122 at about 1543 c i l wave number, a ~p~ctru~ ~typical of DLC ~tructuro.
A~telo~er coating 72 w~ applied to the ~ blad~-dg~ with a nitrogen at~oaphere. The : : r-~ulting co~ting6 58 and 60 wore fir~ly adherent to :
2~313 ~VO 93/00204 PC~r/US92/04932 - 13 - -:
the blade body 50, provided low wet wool felt cutter force (the lowest of the first five cuts with wet wool felt ~L5) being about 0.6 kilogram), and ~' withstood repeated applications of wet wool felt cutter forces (the lowest cutter force of the 496-500 cuts being about 0.76 kilogram), indicating that the DLC coating 60 is substantially unaffected by eYror~re to the severe conditions of this felt cutter test and remains firmly adhered to the blade body S0.
Edge damage and delamination after ten cuts with dry wool felt a~ determined by mi~ copic A~ ment was ~ub~tantially l~ss than commercial chrome-platinum coated blades, there being less than five small edge damage regions (each such small damage region being ~-of less than twenty micrometer dimension and less than ten micrometer depth) and no damage regions of larger dimension or depth. Resulting blade elements 44 were assembled in cartridge units 30 of the type shown in Fig. 2 and shav~d with excellent shaving results.
While particular embodiments of the invention has been shown and described, various modification~ will be apparent to tho~e skilled in the art, and therefore, it i& not inten~e~ that the 2S invention be limitQd to th~ di~closed embodi~ent~, or to d~ailfi thQrQof, and departur~s may b~ made thor~fro~ within ~he spirit and ~~F~ Of the invention.
This invention relates to improved raxurs and razor blades and to procrsrer for producing razor :~
blades or similar cutting tools with sharp and durable cutting edge~. A razor blade typically is formed of a suitable substrate material such as metal or ceramic and an edge is formed with wedge-shape configurat~on with an ulti~ate edge or tip that has a radius of le88 than about 1,000 angstroms. ~uring u e, a razor blade ic h~ld in,the razor at an angle o~ approximately 25 , and wi~h the wedge-shaped edge in contact with the skin, it i~ ~oved o~er the ~ace ~o that wh~ the ~dge ~nco~nter~ a beard hair, it enters and severs it by p~u~essi~e penetration, aided by a wedging action. It i~ believed th~t the cut portion of the hair ~which on average is about 100 micromet~r~ in dia~eter) re~i n~ pre~ed in contact wit~ the blade facets re~ote fro~ the facial ~kin sur~ace for a penetration up to only about h~lf 2 0 the hair dia~e~er. Beyond thi~, th~ hair can band and contract away fro~ th~ bl~d~ to reliQ~e th~
; wQdgin~ forc~ he rQ~istanG~ to pQn~tration through reaction b~tw~n hair and blade fac~t~
therQfore occur~ only ov~r about thQ first sixt~
~icrometar~ o~ the ~lad~ tip back ~rom th~ ~dge and th8 g~ometry of th~ blade tip in thi~ reqion i8 regarded a~ b~ing the most impoxtant from the cutting point o~ ~i8W~
It i~ b~liQved ~hat a raduction in the 1 3 -1 ~
W O 93/00204 PC~r/US92/04932 included angle of the facets would correspondingly reduce the resistance to continued penetration of the blade tip into the hair. However, when the included angle is reduced too much, the strength of the blade 5 tip is inadequate to withstand the resultant bending :
forces on the edge during the cutting process and the tip deforms plastically (or fractures in a brittle ~:
fashion, dependent on the mech~ical properties of :-the material from which it is made) and so sustains permanent damage, which impairQ its ~h-~uent cutting performance, i.e. the edge bscome6 "bluntH or ~dull". As shaving action is severe and blade edge damage fr~ently results, and:to e~hAnce shavability, the use of one or more layers of :~
supplemental coating material has been proposed for shave facilitation, and/or to increase the harAn~c, strength and/or corrosion resi~tance of the shaving edge. A number of such coating materials have been A~ such a~ polymeric ~aterials, metals and alloy~, a~ well a~ other materials including diamond and diamond-like carbon (DLC) ~aterial. ~iamond and diamond-like carbon (DLC) ~aterials may be characterizQd a~ ha~ing ~ubstantial ~p3 carbon h~n~ g; a ~al~8 den ity gr~ater than 1.5 grams/cm3;
and a Raman peak at about 1331 cm-l (dia~ond) or about 1550 cm 1 (DLC). Each ~uch layer or layers of ~upplQ~ental ~aterial desirably provides chAract~ristic~ ~uch as i~proYod ~havsbility, i~prov~d hardnes~,~edge str~ngth and/or corro~ion re~istance while not adver ely a~f~cting the geometry and cutting effectivenes~ of the ~having odge.
In ac~o~dance with one a~pect of the invention, ther i-~provid-d a razor blade compri~ing a~ub~trat~ w1th a:: dge- b~p d ~dg- with a ~harp~ned tip~and;an i w lud d fac-t angl- in th~ rangQ of 10--~- 17- in th- region froa forty to one h~d~ed ~icro~eter~ fron th~ ~ub~trate tip, and a lay~r of w093t002~ ~ 3 PCT/US92/04932 strengthening material on the wedge-shaped edge that is preferably at least twice as hard as the underlying substrate, and has a thickness of at leas~
about twelve hundred angstroms from the tip of the substrate to a distance of forty micrometers from the substrate tip, defines a tip of radiuc of less than about 400 angstroms and that is defined by tip facets with an included angle of at least 60-, and has an asp~ct ratio in the range of 1:1-3:1. The blade ~Yhihits excellent shaving properties and long shaving life.
In particular embodiments, the razor blade sub~trat~ i8 steel; the wedge-shap~d adge is formed by a ~ once of ~e~h~nical abrading steps; a layer of diamond-like carbon material i~ formed by sputtering material from a target of high purity graphite ~n~ ently with the application of an RF
bias to the steel substrate, the DLC layer has a har~n~cs of at least thirteen gi~p~c~ls; and the blade edge ha~ excellent edge strength a~ evidPn~e~
by an L5 wet wool felt cutter force of 1~ ~ than 0.8 kilogram, and n~gligibl~ dry wool felt cutter edge damage (la88 ~han ~ifty small da~age regions (each such s~all daEage region being o~ la~ than tw~nty ~icro~eter di~ension and le88 than ten microm~t~r depth) and no da~age regions of larger dimen6ion or d~pth) ~ ~icroscop~cally A~
In 2ccor~-~c~ wi~h anoth~r asp~ct of the invention, ~h~re i~ pr~vided a ~a~a~ for for~ing a razor blad~ that inolude~ the steps of providing a sub~trat~, for~ing on an adg~ o~ th~ sub~trat~ ~
wed~3 -~p~d sharpenQd ~dge that ha~ an included angle of le~- than thirty da~aa~ and a tip radiu~
(i~e~ th~ ~stioat~d radius of th~ larg-r c~rcl~ that ~ay be po8itioned within the ult~ate tip of the edge when ~u¢h ulti~ate tip is vi~w~d under a ~c~nning electron ~i¢roscope at magnification~ of at leas~
W O 93/00204 PC~r/US92/04932 ;
25,000) of less than twelve hundred angstroms; and ~
depositing a layer of strengthening material on the .
wedge-shaped edge of the substrate while an RF bias is applied to the substrate to provide an aspect 5 ratio in the range of 1:1 - 3:1, and a radius at the ~
ultimate tip of the strengthening material of less ~;
than about five hul.dled al.~aL~oms.
In a particular process, the substrate is ;
mech~nically abraded in a sequence of honing steps to form the sharpened edge: layer~ of an interlayer material and diamond or diamond-like material are successiv-ly ~pQcited by sputtering; the layer of interlayer material having a thic~nq~ of 1e85 than -~
about five h-lnAred ang~troms, and the diamond or DLC
coating having a thickness of at least about twelve h~ e~ a..~.oms with an ultimate tip that i5 defined by tip facets with an included angle of at l~ast 60-; the layer of diamond having a Raman peak at about 1331 c~-l and the layer of diamond-like carbon (DLC) material having a Raman peak at about -~ lS50 cm~l; 8 ~ ~tantial sp3 carbon honAi~; and à
ma~s density grQater than 1.5 grams/cm3; and an adherent polymer coating is applied on the dia~ond or DLC coated cutting edge.
In accor~n~e with another aspect of the in~ention~ there is provided a shaving unit that comprise~ blade 8upport structure that ha~ ~xternal ~urface~ for onq~ging u~r ~kin ah~ 3 and rearwardly of the blad~ ~dge or edg~ and at l~a~t one blade 3Q meD~er securQd to the 8upport structur~ . The ra~or blad~ structure secured to th~ ort stru~L~
include~ ~ substrate with a w~e-~~aped cutting edge dsrined by ~-c t~ th~t~have ~n ~ncluded angle of less th~n ~-v-nt--n~d gr--s at a di-tance of forty : 35 ~icro~ ter- fro~ th~ ~harpened tip, ~nd a l~yer of ~trength-ning -at-rial on the wQdge-~haped cutting edgQ that has a thickness of ~t le~st twelve 1.UndL ed W093/00204 2 ~5 13~1u PCT/uS92/04s32 angstroms from the sharpened tip of the substrate to a distance of forty micrometers from the sharpened tip, and an ultimate tip defined by facets that have lengths of at least about 0.1 micrometer and define an included angle of at least sixty degrees, a radius at the ultimate tip of the strengthening material of les~ than 400 angstroms and an aspect ratio in the range of 1:1-3:1.
In a particular shaving unit, the razor blade ~tructure includes two steel sub~trate~, the wed~a ~ped edges are Ai ~p~-6~ parallel to one another between the skin-engaging ~urfaces; a layer of interlayer material is between the steel substrate and the edge ~-L~ he~in~ layer and is of diamond or 15 DLC material; each layer of interlayer material has a -~
thicknes- of le~s than about five hundred a..~aoms;
each di~ond or DLC coating has a thicknes~ of at lea~t about twelve hundred angstrom~: ~ub~tantial sp3 carbon ~on~n~; a ma~fi density greater than 1.5 gra~/cm3; and a Raman peak at about 1331 ~-1 ' tdiamond) or about 1550 cm~l (D ~); and an adherent polyuer coating i8 on each layer of dia~ond or diamond-like carbon ~aterial.
The ~having unit ~ay be oP the dispo~able 25 c~rtridge typ~ adapted for coupling to and ~ncu~rling -~
fro~ a razor h~nAle or ~ay be integral with a ~Ale 80 th~t the co~plete razor i~ ~scArded as a unit wh~n tha blade or blades b~co~e dull. The front and re~r ~ki.l L..~ging surface~ cooparat~ with the blade 30j edge (or edge~) to define the sha~iny g~ometry.
P~r~c~ rly preferred ~having unita are Or the types ahown in U.S. Patent 3,876,563 and in U.S. Patent 4,586,2~S.
0th r fe~tur ~ and advantagea of ths 3S inv ntion wlIl b- - n aa th~ following d acription 0~ pa~ r Q~bodi~ent~ ~c~lasse~, in con~unction with tho drawing-, in which: -w 1 ~
W093/0~2~ PCT/US92/04932 Fig. 1 is a perspective view of a shaving unit in accordance with the invention;
Fig. 2 is a perspective view of another shaving unit in accordance with the invention;
Fig. 3 is a diagrammatic view illustrating one example of razor blade edge geometry in accordance with the invention;
Fig. 4 is a di~grammatic view of apparatus for th~ practice of the invention; and Figs. 5 and 6 are Raman ~pectra o~ DLC
material ~er~itad with the apparatus of Fig. 4.
DescriDtion of Particular ~hodi~ts ~ With reference to Fig. 1, shaving unit 10 includes structure for attachment to a razor hAnAle, and a platfor~ member 12 molded of high-impact poly~y,ene that includes structure defining forward, trangversely-ex~n~in~ ~kin engaging ~urface 14.
Mounted on platfsr~ m~mber 12 ar~ le~tng blade 16 h~ving sharp~.ne~ ~dge 18 and following blade 20 having sharpened ed~ 22. Cap ~e~ber 24 of molded high-i~pact poly~y~ene ha~ structure defining ~kin-engaging surf~ce 76 that is di~ rearwardly of blade edge 22, and affixed to cap ~e~ber 24 is shaving aid co~po~ite 28.
2 5 The shaving unit 30 ~hown in Fig. 2 is of ~he typ~ ~ho~n in J~h~n U. S. Patent 4,586,255 and includQ~ molded body 32 with f ront portion 34 and r~ar portion 36. R~ ntly ~Qcur~d in body 32 ~r~
guard ~ember 38, l~Ain~ blada unit 40 ~nd trailing blade unit 42. Each blad~ unit 40, 42 înclud~ a blade me~bQr 44 that has a sharp~n~ ~dg~ 46. A
shaving ~id compo8it~ 48 i~ frictionally ~ecurad in a r~.er- in ro~r port;ion 36.
A diagra~atic vi~w of the adge region o~
the blade6 16, 20 and 44 is showrs in Pig. 3. Tha blade includQ~ stainlea~ steel body por~ion 50 with a w~dge-shaped ~harFon~A edge for~ed in a seq~nce of W O 93/00204 ~ ~ t~ 3 PC~r/US92104932 edge forming honing operations that forms a tip portion 52 that has a radius typically less than 500 -angstroms with facets 54 and 56 that diverge at an angle of about 13-. Deposited on tip 52 and facets 54, 56 is interlayer 58 of molybdenum that has a thickness of about 300 angstroms. Deposited on molyhAen~m interlayer 58 is outer layer 60 of diamond-like carbon (DLC) that has a thic~se of about 2,000 a~gstroms, with facets 62, 64 that have lengths of about one-quarter micrometer each and d~fine an includ~d angle of about 80-, facets 62, 64 merging with main facet surfaces 66, 68 that are i spo~~A at an included angle of about 13- and an aspect ratio (the ratio of the distance (a) from DLC
tip 70 to stainless steel tip 52 and the width tb) of the DLC coating 60 at tip 52) of about 1.7.
Depo~ited on layer 60 i~ an adhQrent telomer lay~r 72 that has a ~ubstantial a~ depo6ited thickn~s but is reduced to monolayer thickne-s during initia}
shaving.
Arr~ratus for p~ ing blades o~ the type shown in Fig. 3 i~ diagra~matically illu~trated in Fig. 4. That apparatue includes a DC planar ~agnetron sputtering syste~ manufactured by Vac Tec Sy~t~m~ o~ Boulder, Coloxado that has stainless steel chamb~r 74 with wall ~tructure 80, door 82 and base ~tructure 84 in which i~ for~Qd port 86 couplsd to a 8uit:abl~ vacuu~ ~y~te~ (not ~hown). Mount~d in cha~b~r 74 is carousel support 88 with upg~n~
~ ~rt ~emb~r 90 on which i~ ~~,F-?~ a ~tack o~
razor blade- 92 witb th~ir sharpQn~d ~dgQs 94 in align~nt and faclng outwardly fro~ ~upport 90. Also d~po~od in ch~ber 7~ ar- ~upport ~tructur~ 76 for targ t ~ -b r 96 of ~olybd-nu~ (99.99% purQ) and ~upport ~tructure 78 for ~arg~t a~b~r 98 of graphite (99.999~ pur-). Target~ 96 and 98 are vertically di~pos~d plat~, each about twelve c~nti~Qter~ wide t3 and about thirty-seven centimeters long. Support structures 76, 78 and 88 are electrically isolated from chamber 74 and electrical connections are provided to connect blade stack 92 to RF power supply 100 through switch 102 and to DC power supply 104 through switch 106; and targets 96 and 98 are connected through switches 108, 110, respectively, to DC magnetron power supply 112. Shutter structures 114 and 116 are disposed adjacent targets 96, 98, respectively, for movement between an open position and a position oh~~lring its adjacent target.
Carousel 88 supports the blade stack 92 with the blade edges 94 spaced about seven centimeters from the opposed target plate 96, 98 and is rotatable about a vertical axis between a first position in which blade stack 92 iS in opposed alignment with molybdenum target 96 (Fig. 4) and a ~con~ position in which blade stack 92 i5 in opror~
alignment with graphite target 98.
In a particular processing sequence, a stack of blades 92 (thirty centimeterC high) is ~ecured on ~prQrt 90 (togethQr with three polished stainl~ss steel blade bodiQs di~ parallel to the target); chamber 74 is evacuated; the targets 96, 98 25 are cleaned by DC sputtering for five minutes; switch 102 i8 then closed and the blades 92 are RF cleaned in an argon environment for three minutes at a pr~ssure of ten millitorr, an argon flow of 200 sccm and a power of 1.5 kilowatts; the argon flow i~ then r~ e~ to 150 sccm at a pressure of 4.5 millitorr in chamber 74; switch 106 is clo~ed to apply a DC bia~
of -50 volts on blade~ 92; switch 108 i~ clo~ed to sputter target 96 at one kilowatt power; and shutter 114 in front of molybdenum target 96 is opened; for 35 twenty-eight seconds to deposit a molybdenum layer 58 of about 300 angstroms thicknQss on the blade edges 94. Shutter 114 is then closed, switches 106 and 108 W O 93~00204 21 L1~ 3 Pc~r/us92/o4932 are opened, and carousel 8~ is rotated so to ~:
juxtapose blade stack 92 with graphite target 98.
Pressure in chamber 74 is reduced to two mil~itorr with an argon flow of 150 sccm; switch llo is closed ;~
to sputter graphite target 98 at 500 watts; switch 102 is closed to apply a 13.56 MH~ RF bias of one thousand watts (-440 volts DC self bias voltage) on blades 92, and concurrently shutter 116 is opened for twenty minuteC to deposit a DLC layer 60 of about two ~o~ angstroms thickness on molyhA~n~lm layer 58.
The DLC coating 60 had a radiu~ at tip 70 of about 250 Angstrom~ that is defined by facets 62, 64 that . have an included angle of about 80-, an aspect ratio of about 1.7:1, and a hardnes~ (as measured on the planar surface of an adjacent stainless steel blade body with a Nanoindenter X instrument to a depth of five hl~Ared angstroms) of about se~enteen ~.
gi~ra~CAls (the stainless steel blade body having a har~esc of about eight gi~ ls). A~ illustrated in Fig. 5, Ra~an spectroscopy of the coatin~ mat~rial 60 A~p~Cit~d in thi~ pr~c~r- show~ a broad Raman peak 120 at about 1400-1500 c~-l wave nu~ber, a ~pectrum typical of DLC ~tructure.
A coating 72 of polytetrafluoroethylene telo~er is then applied to the ~LC-coated edges of ~h~ blad~. The process inYolve~ heating th~ blades in a neutral at~osphere of argon and pro~iding on the cutting c~9~ o~ th~ blade~ an adher~nt and friction r~ducing poly~r coating of ~olid PTF~. Coating~ 58 and 60 w~r~ firmly adhersnt ~o thQ blade body 50 and provided low wet wool felt cutter force (the lowest of the fir~t fiv~ cuts with wet wool felt (L5) baing about 0.45 kilogram), and with~tood repaated applicationfi of wet wool felt cutter forces (the low-~t cutter forc~ of the 496-500 cuts b~ng about 0.65 kilograa), indicating that the DLC coating 60 is sub~tantially unaffected by exposure to the sev~re W093/00204 ~ 1 1 ~ 3 ~ ~ pcT/uss2/o4932 -- 10 -- ,, conditions of this felt cutter test and remains firmly adhered to the blade body 50. Edge damage and delamination after ten cuts with dry wool felt as determined by microscopic assessment was 5 substantially less than commercial chrome-platinum -~
coated blades, there being less than four small edge damage regions (each such small damage region being of less than twenty micrometer dimension and less than ten micrometer depth) and no damage regions of larger dimencion or depth. Resulting blade elements 44 were as~emblQd in cartridge units 30 of the type shown in Fig. 2 and shaved with excellent shaving reQultQ.
In another particular proce~ing sequence, a stack of blade~ 92 (thirty centi~eters~high) is secured on ~upport 90 (together with three polished stainle~ st-el blade bodies ~; ~ro~ parallel to the target); cha~b~r 74 is evacuat~d; the targets 96, 98 are cleaned by DC ~LLering-for five ~inute~; switch 102 is th~n clo~Qd and the blade~ 92 are RF cleaned in an argon e m ironment for two and a quarter ~inutes at a pres~ure of t~n ~illltorr, an argon flow of 200 sccm and a power of 1.5 kilowatts, the argon flow i5 then re~c~ to 150 8CC~ at a pre~sure of six millit~rr in cha~ber 74; switch 106 i~ closed to apply a DC bia~ of -S0 volt~ on blad~ 92; shutter 114 in ~ront of ~olybd2nu~ target 96 i8 opened; and ~witch 108 i~ clo~Qd to ~putt-r target 96 at on~
kilowatt povQr for thirty-two ~snA~ to ~po~it a molyhA~n~ layer 58 of about 300 angstro~ thickn~s on the blade odgQ~ 94, Shutter 114 i~ then clo~d, ~witch-~ 106 and 108 are op-n-d, and carou~ol 88 i~ ~
rotatod 90- to ~uxtapo-~ blad ~t~ck 92 with graphite ; t~rg t 98:. ~P~r ~ur in:ch b r 7~ i- roduced to two ~lllltorr w1th un ~rgon flow of 150 ~cc~$ ~witch 110 i~ clo~ed to~putt r graphit~ target 98 at 500 watts;
~ ~w1tch ~02 i- clo~Qd to ~pp~ly a 13.S6 MHz RF bia~ of ,:
~ ' 13.4~",2 W O 93/00204 PC~r/U$92/04932 320 watts (-220 volts DC self bias voltage) on blades 92, and concurrently shutter 116 is opened for seven minutes to deposit a DLC layer 60 of about 900 angstroms thickness on molybdenum layer 58. The DLC
coating 60 had a tip radius of about 300 Angstroms, an aspect ratio of 1.6:1, and a hardness (as measured on the planar surface of an sdjacent stainless steel blade body as measured with a Nanoindenter X
instrument) of about thirteen gi~p~c~ls.
A coating 72 of polyt~trafluoroethyle.ne telomer is then applied to the D~C-coat~d edge~ of the blades in accordance with the teaching of U.S.
Patent No. 3,518,110. The process involved heating the blades in a neutral ~t~osphere of argon and 1~ providing on the cutting edges of th~ blades an adherent and friction-reducing polymer coating o~
solid PTFE. Coating~ 58 and 60 w~re firmly adherent to ~he blade body 50, provided low wet wool felt cutter force (the lowest of the ~irst five cut~ with wet ~ool felt (L5) being about 0.6 kilogram), and with~tood repeated applications of w~t wool folt cutter forc~ (the l~we~t cutter force of the 496-500 cuts being about 0.76 kilogr~, indicating that the DLC coating 6~ is substantlally unaf~Qct~d by ~ re ts:~ the savere condition o~ thlB f~lt cutter test and r~ain~ firmly adher~d to th~ ~lade body 50.
Edge da~age and dela~ination after t~n cuts with dry wool felt ~s d~t~r~ined by ~icro~copic A-~ersment was substaintially ~ 8 than com~ercial chrome-plat~nu~
coat~d bl~ , there h~~n~ lfi~ ~han four ~mall edge . damag~ region~ ch ~uch ~all da~aqe region being of le8~ than tw~nty ~icro~ter di~en~ion and 1~
than ton ~icro~ster d~pth~ and no da~ag~ region~ of larg~r dimen~on or d~pth. ~o~tting 1~ 9 el~ments 44 wer~ a~QEbl~d in cartridg~ ~nit8 30 of tbe ~ype shown in Fig. 2 and ~ha~ed with ~xcellent ~having result~.
W093/002~ 2 ~ 1 1 3 1 ~ PCT/US92/04~32 In another processing sequence, chamber 74 is evacuated; the targets 96, 98 are cleaned by DC
sputtering for five minutes; switch 102 is then closed and the blades 92 are RF cleaned in an argon environment for two and a quarter minutes at a pressure of ten millitorr, an argon flow of 200 sccm and a power of 1.5 kilowatts; the argon flow is then r~ d to 150 sccm at a pres~ure of six millitorr in chamber 74; switch 106 is closed to apply a DC bias of -50 volts on blades 92; shutter 114 in front of moly M enum target 96 is opened; and switch 108 is closed to sputter target 96 at one kilowatt power for thirty-two ~eco~A~ to deposit a DolyhA~nl~m Iayer 58 of abou~ 300 ang troms thir~ne-- on the blade edges 94. Shutter 114 is then closed, switches 106 and 108 are opened, a~nd:carousel 88 is rotated 90- to juxtArore blade stack 92 with graphite target 98.
Pre~ ~e in chamber 74 is re~ to two millitorr :~
wi:th an argon rlOw of 150 scGm; switch 110 is closed to sputter graphite target 98 at 500 watts: switch 102 is closod to apply a 13.~56 ~Hz RF bias of 320 watt~ ~-220 volts DC self bi~s voltage) on blades 92, : and ron~rrently shutter 116 i~ opened for five minute~ to ~e~o~it a D~C layer 60 of abou~ 600 a..~ oms thic~ç~ on ~olyhAen~l~ layer 58. The DLC
coating 60 had a tip radiufi of about 400 Angstro~s, an ~pect ratio of 1.7:1, and a hardnes~ (as ~easured on tb- plan~r ~urfac~ of ~n adjac~nt ~tainl~ te~l blade body as ~oasured with ~ Nanoln~nter X
in~trumont) of about thirteon gig~pa~cals. A8 -illu~trated in Fig. 6, Ra~an ~pectroscopy of the coating ~aterial 60 A~po~ited in thi~ PL~r- ~hows a broad Raman peak 122 at about 1543 c i l wave number, a ~p~ctru~ ~typical of DLC ~tructuro.
A~telo~er coating 72 w~ applied to the ~ blad~-dg~ with a nitrogen at~oaphere. The : : r-~ulting co~ting6 58 and 60 wore fir~ly adherent to :
2~313 ~VO 93/00204 PC~r/US92/04932 - 13 - -:
the blade body 50, provided low wet wool felt cutter force (the lowest of the first five cuts with wet wool felt ~L5) being about 0.6 kilogram), and ~' withstood repeated applications of wet wool felt cutter forces (the lowest cutter force of the 496-500 cuts being about 0.76 kilogram), indicating that the DLC coating 60 is substantially unaffected by eYror~re to the severe conditions of this felt cutter test and remains firmly adhered to the blade body S0.
Edge damage and delamination after ten cuts with dry wool felt a~ determined by mi~ copic A~ ment was ~ub~tantially l~ss than commercial chrome-platinum coated blades, there being less than five small edge damage regions (each such small damage region being ~-of less than twenty micrometer dimension and less than ten micrometer depth) and no damage regions of larger dimension or depth. Resulting blade elements 44 were assembled in cartridge units 30 of the type shown in Fig. 2 and shav~d with excellent shaving results.
While particular embodiments of the invention has been shown and described, various modification~ will be apparent to tho~e skilled in the art, and therefore, it i& not inten~e~ that the 2S invention be limitQd to th~ di~closed embodi~ent~, or to d~ailfi thQrQof, and departur~s may b~ made thor~fro~ within ~he spirit and ~~F~ Of the invention.
Claims (16)
1. A process for forming a razor blade comprising the steps of providing a substrate, forming a wedge-shaped sharpened edge on said substrate that has an included angle of less than thirty degrees and a tip radius of less than twelve hundred angstroms;
disposing said substrate and a solid target member in a chamber; and sputtering said solid target member to generate carbon atoms for forming a layer of diamond or diamond-like carbon material on said sharpened edge of said substrate from said carbon atoms from said solid target member while an RF bias is applied to said substrate; said layer of diamond or diamond-like carbon material having a radius at the ultimate tip of said diamond or diamond-like carbon material of less than 500 angstroms and an aspect ratio in the range of 1:1-3:1.
disposing said substrate and a solid target member in a chamber; and sputtering said solid target member to generate carbon atoms for forming a layer of diamond or diamond-like carbon material on said sharpened edge of said substrate from said carbon atoms from said solid target member while an RF bias is applied to said substrate; said layer of diamond or diamond-like carbon material having a radius at the ultimate tip of said diamond or diamond-like carbon material of less than 500 angstroms and an aspect ratio in the range of 1:1-3:1.
2. The process of claim 1 wherein said substrate is mechanically abraded in a sequence of grinding, rough-honing and finish-honing steps to form said sharpened edge.
3. The process of claim 2 wherein said finish-honing step forms facets that have an included angle of less than thirty degrees.
4. The process of claim 1 and further including the step of applying an adherent polymer coating on said diamond or diamond-like carbon coated sharpened edge.
5. The process of claim 1 and further including the step of depositing a layer of molybdenum on said sharpened edge; and said layer of diamond or diamond-like carbon material is deposited on said molybdenum layer.
6. The process of claim 5 wherein said molybdenum layer on said cutting edge is deposited to a thickness of less than about five hundred angstrom, and said diamond or diamond-like carbon coating on said molybdenum coated sharpened edge is deposited to a thickness of less than about two thousand angstroms.
7. The process of claim 1 wherein said solid target member is of high purity graphite; said layer of diamond or diamond-like carbon material is deposited in an argon atmosphere in an evacuated chamber in which said high purity graphite target and a shutter are located; said graphite target is energized; said RF bias is applied to said substrate; and said shutter is opened to deposit said layer of diamond or diamond-like carbon material on said sharpened edge while said RF bias is applied to said substrate.
8. The process of claim 7 and further including a molybdenum target in said chamber, and further including the step of depositing a molybdenum layer on said blade edge.
9. A process for forming a razor blade comprising the steps of providing a substrate, forming on said substrate a wedge-shaped edge that has an included angle of less than 30° and a tip radius less than 1,000 angstroms; disposing said substrate and a solid target member in a chamber; and sputtering said solid target member to generate carbon atoms for forming a layer of diamond or diamond-like carbon material on said wedge-shaped edge while an RF bias is applied to said substrate to provide a radius at the ultimate tip of said diamond or diamond-like carbon material of less than 500 angstroms and an aspect ratio in the range of 1:1-3:1.
10. The process of claim 9 wherein said solid target member is of high purity graphite; said layer of diamond or diamond-like material is deposited in an argon atmosphere in an evacuated chamber in which said high purity graphite target and a shutter are located; said graphite target is energized; said RF bias is applied to said substrate; and said shutter is opened to deposit said layer of diamond or diamond-like material on said edge while said RF bias is applied to said substrate.
11. The process of claim 9 wherein said diamond or diamond-like carbon coating on said wedge-shaped wedge is deposited to a thickness of less than about two thousand angstroms.
12. The process of claim 11 and further including the step of applying an adherent polymer coating on said diamond or diamond-like carbon coated wedge-shaped edge.
13. A razor blade comprising a substrate with a wedge-shaped edge defined by a sharpened tip and facets that have an included angle of less than seventeen degrees at a distance of forty micrometers from the sharpened tip, and a layer of strengthening material on said wedge-shaped edge, said layer of strengthening material being at least twice as hard as said substrate and having a thickness of at least twelve hundred angstroms from the sharpened tip of said substrate to a distance of forty micrometers from the sharpened tip, and an ultimate tip defined by facets that have lengths of at least about 0.1 micrometer and define an included angle of at least sixty degrees, an L5 wet wool felt cutter force of less than 0.8 kilogram, dry wool felt (ten cuts) edge damage of less than fifty small edge damage regions and no damage regions of larger dimension or depth, a radius at the ultimate tip of said diamond or diamond-like material of less than 400 angstroms and an aspect ratio in the range of 1:1-3:1.
14. The razor blade of claim 13, wherein said layer of strengthening material is diamond or diamond-like carbon (DLC) material that has a hardness of at least thirteen gigapascal; substantial sp3 carbon bonding; a mass density greater than 1.5 grams/cm3; and a Raman peak at about 1331 cm-1 (DLC) or about 1550 cm-1 (DLC); and further including an adherent polymer coating on said layer of diamond or diamond-like carbon material.
15. The razor blade of claim 13 or 14, and further including a layer of interlayer material on said wedge-shaped edge; said layer of interlayer material having a thickness of less than about five hundred angstroms.
16. The razor blade of claim 15, wherein said substrate is steel; said wedge-shaped edge is formed by a sequence of mechanical abrading steps; and said layers of interlayer material and diamond or diamond-like carbon material are formed by sputtering.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US719,793 | 1991-06-24 | ||
| US07/719,793 US5232568A (en) | 1991-06-24 | 1991-06-24 | Razor technology |
| US79242791A | 1991-11-15 | 1991-11-15 | |
| US792,427 | 1991-11-15 | ||
| PCT/US1992/004932 WO1993000204A1 (en) | 1991-06-24 | 1992-06-11 | Improvements in or relating to razor blades |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2111343A1 CA2111343A1 (en) | 1993-01-07 |
| CA2111343C true CA2111343C (en) | 1998-07-28 |
Family
ID=27110143
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002111343A Expired - Fee Related CA2111343C (en) | 1991-06-24 | 1992-06-11 | Improvements in or relating to razor blades |
Country Status (19)
| Country | Link |
|---|---|
| EP (1) | EP0591339B1 (en) |
| JP (1) | JP3722829B2 (en) |
| KR (1) | KR100245979B1 (en) |
| CN (1) | CN1039793C (en) |
| AT (1) | ATE169547T1 (en) |
| AU (1) | AU667816B2 (en) |
| CA (1) | CA2111343C (en) |
| CZ (1) | CZ286598B6 (en) |
| DE (1) | DE69226640T2 (en) |
| DK (1) | DK0591339T3 (en) |
| EG (1) | EG19616A (en) |
| ES (1) | ES2118821T3 (en) |
| MA (1) | MA22561A1 (en) |
| MX (1) | MX9203147A (en) |
| MY (1) | MY110072A (en) |
| PL (1) | PL170815B1 (en) |
| TR (1) | TR27155A (en) |
| TW (1) | TW215423B (en) |
| WO (1) | WO1993000204A1 (en) |
Families Citing this family (29)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ZA928617B (en) * | 1991-11-15 | 1993-05-11 | Gillette Co | Shaving system. |
| AU2392295A (en) * | 1994-04-25 | 1995-11-16 | Gillette Company, The | Amorphous diamond coating of blades |
| US5490329A (en) * | 1994-05-17 | 1996-02-13 | The Gillette Company | Shaving system |
| US5693094A (en) | 1995-05-09 | 1997-12-02 | Allergan | IOL for reducing secondary opacification |
| US6162249A (en) * | 1998-05-29 | 2000-12-19 | Allergan | IOI for inhibiting cell growth and reducing glare |
| US6468306B1 (en) | 1998-05-29 | 2002-10-22 | Advanced Medical Optics, Inc | IOL for inhibiting cell growth and reducing glare |
| US6884262B2 (en) | 1998-05-29 | 2005-04-26 | Advanced Medical Optics, Inc. | Enhanced intraocular lens for reducing glare |
| EA002735B1 (en) * | 1998-12-24 | 2002-08-29 | Конинклейке Филипс Электроникс Н.В. | Method of manufacturing a cutter member having an auxiliary layer |
| US6684513B1 (en) | 2000-02-29 | 2004-02-03 | The Gillette Company | Razor blade technology |
| US20050028389A1 (en) * | 2001-06-12 | 2005-02-10 | Wort Christopher John Howard | Cvd diamond cutting insert |
| JP4246060B2 (en) * | 2001-07-11 | 2009-04-02 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | Cutting member with dual profile tip |
| US6648741B2 (en) | 2002-03-14 | 2003-11-18 | Advanced Medical Optics, Inc. | Apparatus for protecting the edge geometry of an intraocular lens during glass bead polishing process |
| GB0212530D0 (en) * | 2002-05-30 | 2002-07-10 | Diamanx Products Ltd | Diamond cutting insert |
| WO2004018166A1 (en) * | 2002-08-21 | 2004-03-04 | Koninklijke Philips Electronics N.V. | A cutting member having a superlattice coating |
| US7615073B2 (en) | 2003-12-09 | 2009-11-10 | Advanced Medical Optics, Inc. | Foldable intraocular lens and method of making |
| JP4842835B2 (en) | 2003-12-09 | 2011-12-21 | アボット・メディカル・オプティクス・インコーポレイテッド | Foldable intraocular lens and manufacturing method thereof |
| US20070186424A1 (en) * | 2006-02-10 | 2007-08-16 | Eveready Battery Company, Inc. | Multi-layer coating for razor blades |
| US7882640B2 (en) * | 2006-03-29 | 2011-02-08 | The Gillette Company | Razor blades and razors |
| US8011104B2 (en) | 2006-04-10 | 2011-09-06 | The Gillette Company | Cutting members for shaving razors |
| US20130014395A1 (en) | 2011-07-14 | 2013-01-17 | Ashok Bakul Patel | Razor blades having a large tip radius |
| US20130014396A1 (en) * | 2011-07-14 | 2013-01-17 | Kenneth James Skrobis | Razor blades having a wide facet angle |
| CN106584525A (en) * | 2015-10-20 | 2017-04-26 | 余荣恺 | Hair clipper head and manufacturing method thereof |
| EP3372362A1 (en) * | 2017-03-08 | 2018-09-12 | BIC-Violex S.A. | Razor blade |
| BR112022020870A2 (en) | 2020-04-16 | 2022-11-29 | Gillette Co Llc | COATINGS FOR A SHAVING OR SHAVING BLADE |
| EP4135952A2 (en) | 2020-04-16 | 2023-02-22 | The Gillette Company LLC | Coatings for a razor blade |
| WO2021211812A1 (en) | 2020-04-16 | 2021-10-21 | The Gillette Company Llc | Multi-layer coatings for a razor blade |
| US20230373121A1 (en) | 2022-05-20 | 2023-11-23 | The Gillette Company Llc | Non-fluorinated organic coating material for a razor blade |
| US20230373120A1 (en) | 2022-05-20 | 2023-11-23 | The Gillette Company Llc | Method of coating a razor blade |
| DE102022213666A1 (en) * | 2022-12-14 | 2024-06-20 | Wmf Gmbh | Cutting blade and method for its manufacture |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3480483A (en) * | 1965-05-06 | 1969-11-25 | Wilkinson Sword Ltd | Razor blades and methods of manufacture thereof |
| US3349488A (en) * | 1966-08-09 | 1967-10-31 | Burnie J Craig | Razor blades |
| US3829969A (en) * | 1969-07-28 | 1974-08-20 | Gillette Co | Cutting tool with alloy coated sharpened edge |
| US3802078A (en) * | 1971-06-07 | 1974-04-09 | P Denes | Cutting device and method for making same |
| US3761372A (en) * | 1971-07-09 | 1973-09-25 | Gillette Co | Method for producing an improved cutting tool |
| US4291463A (en) * | 1979-12-31 | 1981-09-29 | Warner-Lambert Company | Water-soluble shaving aid for razor blades |
| DE3047888A1 (en) * | 1980-12-19 | 1982-07-15 | Philips Patentverwaltung Gmbh, 2000 Hamburg | Cutting tools, esp. razor blades - where CVD activated by plasma is used to coat tool with carbon possessing structure similar to diamond |
| BR8307616A (en) * | 1982-11-19 | 1984-10-02 | Gillette Co | SHAVING BLADES |
| US4586255A (en) * | 1984-10-15 | 1986-05-06 | The Gillette Company | Razor blade assembly |
| US4933058A (en) * | 1986-01-23 | 1990-06-12 | The Gillette Company | Formation of hard coatings on cutting edges |
| ES2143473T3 (en) * | 1991-04-26 | 2000-05-16 | Gillette Co | IMPROVEMENTS IN OR RELATED TO SHAVING BLADES. |
-
1992
- 1992-06-11 JP JP50151393A patent/JP3722829B2/en not_active Expired - Lifetime
- 1992-06-11 DK DK92913506T patent/DK0591339T3/en active
- 1992-06-11 EP EP92913506A patent/EP0591339B1/en not_active Expired - Lifetime
- 1992-06-11 AU AU21927/92A patent/AU667816B2/en not_active Ceased
- 1992-06-11 WO PCT/US1992/004932 patent/WO1993000204A1/en active IP Right Grant
- 1992-06-11 CZ CZ19932890A patent/CZ286598B6/en not_active IP Right Cessation
- 1992-06-11 PL PL92301887A patent/PL170815B1/en unknown
- 1992-06-11 AT AT92913506T patent/ATE169547T1/en not_active IP Right Cessation
- 1992-06-11 KR KR1019930704033A patent/KR100245979B1/en not_active IP Right Cessation
- 1992-06-11 ES ES92913506T patent/ES2118821T3/en not_active Expired - Lifetime
- 1992-06-11 CA CA002111343A patent/CA2111343C/en not_active Expired - Fee Related
- 1992-06-11 DE DE69226640T patent/DE69226640T2/en not_active Expired - Lifetime
- 1992-06-16 MY MYPI92001025A patent/MY110072A/en unknown
- 1992-06-22 MA MA22851A patent/MA22561A1/en unknown
- 1992-06-23 MX MX9203147A patent/MX9203147A/en unknown
- 1992-06-23 EG EG33092A patent/EG19616A/en active
- 1992-06-23 TR TR00581/92A patent/TR27155A/en unknown
- 1992-06-24 CN CN92105085.2A patent/CN1039793C/en not_active Expired - Lifetime
- 1992-06-24 TW TW081104972A patent/TW215423B/zh active
Also Published As
| Publication number | Publication date |
|---|---|
| KR100245979B1 (en) | 2000-05-01 |
| MY110072A (en) | 1997-12-31 |
| DK0591339T3 (en) | 1999-02-15 |
| AU667816B2 (en) | 1996-04-18 |
| ES2118821T3 (en) | 1998-10-01 |
| TW215423B (en) | 1993-11-01 |
| CZ286598B6 (en) | 2000-05-17 |
| CZ289093A3 (en) | 1995-04-12 |
| EP0591339A1 (en) | 1994-04-13 |
| AU2192792A (en) | 1993-01-25 |
| PL170815B1 (en) | 1997-01-31 |
| EP0591339A4 (en) | 1994-08-31 |
| JP3722829B2 (en) | 2005-11-30 |
| EP0591339B1 (en) | 1998-08-12 |
| CA2111343A1 (en) | 1993-01-07 |
| MX9203147A (en) | 1993-02-01 |
| CN1039793C (en) | 1998-09-16 |
| CN1068990A (en) | 1993-02-17 |
| WO1993000204A1 (en) | 1993-01-07 |
| JPH07503377A (en) | 1995-04-13 |
| MA22561A1 (en) | 1992-12-31 |
| DE69226640D1 (en) | 1998-09-17 |
| EG19616A (en) | 1995-07-27 |
| DE69226640T2 (en) | 1999-03-18 |
| ATE169547T1 (en) | 1998-08-15 |
| TR27155A (en) | 1994-11-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |