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Publication numberUS3480483 A
Publication typeGrant
Publication dateNov 25, 1969
Filing dateMay 4, 1966
Priority dateMay 6, 1965
Also published asDE1553843A1, DE1553843B2
Publication numberUS 3480483 A, US 3480483A, US-A-3480483, US3480483 A, US3480483A
InventorsWilkinson Anthony E F
Original AssigneeWilkinson Sword Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Razor blades and methods of manufacture thereof
US 3480483 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

United States Patent US. Cl. 148-63 11 Claims ABSTRACT OF THE DISCLOSURE Coatings are formed on the cutting edge of steel razor blades by the steps of cleaning the cutting edge, applying to the cutting edge a thin layer of chromium of less than 400 Angstroms in thickness, preferably of less than 100 Angstroms, after which the blade is heat treated in a controlled oxidising atmosphere. The heat treating may be at a temperature of approximately 400 C. and at a pressure of approximately 10* torricelli.

The chromium content of the blades may be increased in the surface region of the cutting edge by a chromating process. Conversion of a substantial portion of the chromium on the cutting edge to chromium oxide may be effected by anodising, for example by means of a glow discharge or in a liquid electrolyte.

This invention relates to razor blades.

According to the present invention at least the surface region of at least the cutting edge or cutting edges of a razor blade comprise chromium oxide.

The provision of such a surface comprising chromium oxide is designed to impart improved properties to the razor blade by giving enhanced durability to the cutting edge or edges.

One method of providing the chromium oxide surface is first to coat with chromium which is thereafter oxidised. An alternative method is to coat the surface with chromium oxide thereby eliminating the oxidising step. Yet another method is to enrich the chromium content of at least the surface region of a stainless steel razor blade by a chromating process with subsequent oxidisation.

In greater detail, one method of manufacture is to clean the cutting edge or edges, thereafter applying a thin layer of chromium, for example, less than 400 Angstroms in thickness. A thickness of less than 100 Angtroms is preferred. The blade is next annealed to improve the bond with the coating and is then heat-treated in a controlled oxidising atmosphere. The chromium coating and subsequent heat treatment can be effected without impairing the cutting edge and in some circumstances may be efiected as a single operation.

Thereafter the blades may be provided with coatings or particles of materials to facilitate shaving, such as the already known or novel coatings referred to in the specification of Belgian Patent No. 504,784 of Apr. 5, 1963 in the name of Wilkinson Sword Limited. The heat treatment required to cure the polytetrafluoroethylene will in some cases be adequate to ensure adhesion between the vapour deposited chromium and the blade edge.

The method chosen for cleaning the blade should take account of the properties of the blade material, typical methods being by immersion in an organic solvent, for example, trichloroethylene, if necessary under ultrasonic vibration, with subsequent drying, by vapor degreasing in trichloroethylene, by glow discharge or by a brief anodic etching. If the latter method is used with an 3,480,483 Patented Nov. 25, 1969 aqueous solution of chromium trioxide, this can constitute the chromating process referred to above.

The selected method of coating the blade can likewise be chosen to 'be the most suitable for the material in question and examples of possible methods are by vapour deposition, by sputtering, possible with the sputtering direction in an ion beam, by electro-plating or by gas reaction.

Finally, it is necessary to effect controlled oxidation of the metal surface. This may be achieved by heat treatment in a controlled atmosphere in which the amount of oxygen present is strictly limited; for example the blade may be heated to 400 C. in air at a pressure of 10 torricelli. Another method is to anodise in a gaseous or liquid electrolyte; for example anodising may be by means of an air glow discharge at a low pressure, say a pressure of microns. A feature of the invention is that the amount of oxygen present during the oxidation process is strictly controlled.

Thus, considering the application of the process to stainless steels which can be used for razor blades, the process may typically involve vapour degreasing in trichloroethylene or chloroform, coating with chromium by vapour deposition, annealing in vacuum to bond the deposit to the edge, oxidising in a controlled atmosphere at temperatures up to 450 C. and applying a coating of polytetrafluoroethylene.

I claim:

1. The method of forming a chromium oxide coating on a cutting edge of a stainless steel razor blade comprising the steps of enriching the chromium content in the surface region of said cutting edge by a chromating process, and heat treating the cutting edge in a controlled oxidising atmosphere.

2. The method of forming a chromium oxide coating on a cutting edge of a steel razor blade comprising the steps of cleaning the cutting edge,

applying to the cutting edge a thin layer of chromium of less than 400 Angstroms in thickness, and

heat treating the blade in a controlled oxidising atmosphere to convert a substantial proportion of the chromium to chromium oxide.

3. The method according to claim 2, wherein said heat treating comprises heating to a temperature of approximately 400 C. in air at very low pressure.

4. The method according to claim 2, wherein said chromium is applied by vapour deposition.

5. The method according to claim 2, wherein said chromium is applied by sputtering.

6. The method according to claim 2, wherein said controlled oxidising atmosphere is at a pressure of approxi mately 1O torricelli.

7. The method according to claim 2, wherein said coating of chromium is of less than 100 Angstroms.

8. The method according to claim 2, comprising the further step of applying to the chromium oxide coating a coating of polytetrafluoroethylene.

9. The method of forming a chromium oxide coating on a cutting edge of a steel razor blade comprising the steps of cleaning the cutting edge,

applying to the cutting edge a thin layer of chromium of less than 400 Angstroms in thickness, and anodising the chromium coating to convert a substantial proportion of the chromium to chromium oxide.

10. The method according to claim 9, wherein the anodising is effected by means of a glow discharge in the presence of a restricted amount of oxygen.

11. The method according to claim 9, wherein the anodising is eflected in a liquid electrolyte.

References Cited UNITED STATES PATENTS 4 FOREIGN PATENTS 6/1949 Canada. 4/ 1967 Great Britain.

5 RALPH S. KENDALL, Primary Examiner US. Cl. X.R.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3071856 *Dec 31, 1959Jan 8, 1963Irwin W FischbeinRazor blade and method of making same
US3283117 *Apr 22, 1965Nov 1, 1966Philip Morris IncMethod for coating cutting edges of sharpened instruments
US3345202 *Jun 10, 1963Oct 3, 1967Eversharp IncMethod of making razor blades
CA457378A *Jun 14, 1949Gillette Safety Razor CoFine edged cutting implements and the manufacture thereof
GB1065723A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3634147 *Nov 20, 1969Jan 11, 1972United States Steel CorpCorrosion resistant tin-free steel and method for producing same
US3635811 *Nov 6, 1967Jan 18, 1972Warner Lambert CoMethod of applying a coating
US3652443 *Aug 25, 1970Mar 28, 1972Gillette CoDeposition apparatus
US3754329 *Sep 29, 1971Aug 28, 1973Warner Lambert CoRazor blade with rf sputtered coating
US3773544 *Jun 1, 1971Nov 20, 1973Steel CorpFluorocarbon polymer coated substrate
US3805387 *May 22, 1972Apr 23, 1974American Optical CorpFiber razor blade
US3811189 *Mar 19, 1973May 21, 1974Gillette CoProcess for producing an improved cutting tool
US3829969 *Nov 5, 1970Aug 20, 1974Gillette CoCutting tool with alloy coated sharpened edge
US3835537 *Mar 19, 1973Sep 17, 1974Gillette CoImproved cutting tool
US3871836 *Dec 20, 1972Mar 18, 1975Allied ChemCutting blades made of or coated with an amorphous metal
US3890109 *Apr 6, 1973Jun 17, 1975Wilkinson Sword LtdRazor blades having high purity Al{hd 2{b O{HD 3 {B coating
US3900636 *Jul 18, 1974Aug 19, 1975Gillette CoMethod of treating cutting edges
US3904506 *Sep 25, 1973Sep 9, 1975Shatterproof Glass CorpApparatus for continuous production of sputter-coated glass products
US3911579 *Apr 18, 1973Oct 14, 1975Warner Lambert CoCutting instruments and methods of making same
US3916523 *Dec 26, 1973Nov 4, 1975Warner Lambert CoCoated razor blade
US3939293 *Apr 30, 1974Feb 17, 1976International Business Machines, CorporationMethod for passivating chromium
US3968018 *Jul 25, 1974Jul 6, 1976Warner-Lambert CompanySputter coating method
US4262875 *Aug 17, 1979Apr 21, 1981Rca CorporationInformation record stampers
US4726368 *Oct 1, 1986Feb 23, 1988Bioquantum Technologies, Inc.Non-reflective surgical instruments
US5295305 *Jan 25, 1993Mar 22, 1994The Gillette CompanyRazor blade technology
US5301431 *Dec 1, 1992Apr 12, 1994Etm CorporationHand-held cutting tool
US6684513 *Feb 29, 2000Feb 3, 2004The Gillette CompanyRazor blade technology
US6866894Jul 10, 2002Mar 15, 2005The Gillette CompanyRazor blade technology
US7673541 *Jun 3, 2004Mar 9, 2010The Gillette CompanyColored razor blades
US7935385 *May 3, 2011Tadahiro OhmiMetal material having formed thereon chromium oxide passive film and method for producing the same, and parts contacting with fluid and system for supplying fluid and exhausting gas
US8505414Jun 17, 2009Aug 13, 2013Stanley Black & Decker, Inc.Method of manufacturing a blade
US8769833Sep 10, 2010Jul 8, 2014Stanley Black & Decker, Inc.Utility knife blade
US9032628 *Jan 13, 2012May 19, 2015Eveready Battery Company, Inc.Razor blade technology
US9149944 *Dec 12, 2014Oct 6, 2015Eveready Battery Company, Inc.Razor blade technology
US9180599Sep 8, 2004Nov 10, 2015Bic-Violex S.A.Method of deposition of a layer on a razor blade edge and razor blade
US20030121158 *Feb 10, 2003Jul 3, 2003The Gillette Company, A Delaware CorporationRazor blade technology
US20040172832 *Mar 4, 2003Sep 9, 2004Colin ClipstoneRazor blade
US20050268470 *Jun 3, 2004Dec 8, 2005Skrobis Kenneth JColored razor blades
US20060174977 *Aug 21, 2003Aug 10, 2006Tadahiro OhmiMetal material having formed thereon chromium oxide passive film and method for producing the same, and parts contacting with fluid and system for supplying fluid and exhausting gas
US20060265885 *Mar 14, 2006Nov 30, 2006The Gillette Company, A Delaware CorporationRazor blade
US20080190758 *Sep 8, 2004Aug 14, 2008Vassilis PapachristosMethod of Deposition of a Layer on a Razor Blade Edge and Razor Blade
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US20130180117 *Jan 13, 2012Jul 18, 2013Eveready Battery Company Inc.Razor Blade Technology
US20150096164 *Dec 12, 2014Apr 9, 2015Eveready Battery Company Inc.Razor Blade Technology
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DE19800758A1 *Jan 12, 1998Jul 15, 1999Fraunhofer Ges ForschungVerfahren zum Beschichten von Folie aus Nickel oder einer Nickellegierung und beschichtete Folie aus Nickel oder einer Nickellegierung
DE19800758C2 *Jan 12, 1998Aug 31, 2000Fraunhofer Ges ForschungVerfahren zum Beschichten von Folie aus Nickel oder einer Nickellegierung und beschichtete Folie aus Nickel oder einer Nickellegierung
EP0591339A1 *Jun 11, 1992Apr 13, 1994The Gillette CompanyImprovements in or relating to razor blades
WO1992019425A2 *Apr 22, 1992Nov 12, 1992The Gillette CompanyImprovements in or relating to razor blades
WO1992019425A3 *Apr 22, 1992Jan 21, 1993Gillette CoImprovements in or relating to razor blades
Classifications
U.S. Classification148/276, 30/346.53, 428/469, 205/188, 204/192.16, 148/286
International ClassificationC23C10/60, C23C8/02, C23C14/58, C23C10/00, C23C14/16
Cooperative ClassificationC23C14/16, C23C14/5853, C23C10/60, C23C14/58, C23C8/02
European ClassificationC23C14/16, C23C8/02, C23C14/58, C23C10/60, C23C14/58H2