Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/58—After-treatment
  • C23C14/5806—Thermal treatment
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
  • B05D7/14—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to metal, e.g. car bodies
• • 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
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D127/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Coating compositions based on derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/58—After-treatment
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/58—After-treatment
  • C23C14/5846—Reactive treatment
  • C23C14/5853—Oxidation

Definitions

• the present invention is concerned with steel razor blades having a fluorocarbon polymeric coating thereon and more particularly with processes for producing improved blades of that nature. Generally, the improvements are brought about by providing a thin, cubic iron oxide layer beneath the polymeric coating.
• One object of the present invention is to provide razor blades and particularly carbon steel blades having fluorocarbon coatings thereon which blades have extended use life.
• Another object of the present invention is to provide processes for producing such blades.
• the resulting blades surprisingly have a longer useful life during which the benefits derived from such coatings are enjoyed.
• the extended life is particularly noticeable with carbon steel blades wherein the benefits derived from such fluorocarbon coatings are appreciated for up to about 40 to 100 percent more shaves.
• the blades upon which the processes of the present invention will be carried out will have wedged-shaped cutting edges, the included angle of which will usually lie between about to 35.
• the faces of such wedged-shaped cutting edges may extend back from the ultimate edge as much as 0.25 cm. or more and may comprise a single, uninterrupted, continuous facet or a plurality of facets formed by successive grinding and honing operations.
• the ultimate edge will usually have a thickness of less than 0.6 microns and preferably less than 0.25 microns.
• the solid fluorocarbon polymeric coatings which are applied to the cutting edge may extend over the entire wedge faces or at a minimum will usually cover at least a major portion of the zones immediately adjacent the ultimate edge.
• such zones will begin at the ultimate edge or within a micron or less from it and extend back from it for a distance of about 50 microns or more.
• the fluorocarbon coatings will usually be in the neighborhood of from about 0.1 to 0.3 microns in thickness.
• Blades having a cubic iron oxide surface layer on their cutting edges may be produced by stopping the above described oxidation in any of the cubic stages before the a- TABLE I Period during which cubic Oxide outer layers will be i 0, Pressure Temperature Forming l. 0.01 torr to 220 C. (428 F.) Up to at least 10 torr I50 minutes (a torr equals about I mm. of Hg) 2. I00 torr 220 C. (428 F.) Up to at least 20 minutes 3. 0.0] ton to 270 C. (5l8 F.) Up to at least 10 torr 30 minutes 4. 0.0] torr 350 C.
• Cubic oxides of iron when viewed under an electron microscope, are characterized by having a smooth, finegrained structure and are readily distinguishable from the a- Fe 0 which is rhombohedral and has a coarse-grained herringbone-like structure. Accordingly, one will have little trouble in finding the conditions best suited to his particular needs informing the cubic oxide on the cutting edges.
• the oxide immediately underlying substantially the entire fluorocarbon coating on the cutting edge is essentially of the cubic nature.
• the improvements provided by the present invention begin to become particularly noticeable when the cubic oxide layer is at least about 50 A. in thickness.
• the optimum thickness range generally lies between about 50 A. to 800 A. and more preferably between about 50 to 400 A. Thicker layers may be employed but it should be kept in mind that the quality of at least the first shave may begin to be adversely affected as the thickness increases.
• cubic iron oxides When the cubic oxides are formed on stainless steel blades, a portion of the iron atoms in the cubic structure will be replaced by chromium atoms.
• the term cubic iron oxides as used herein is intended to include such structures.
• the cubic oxides may be formed on the cutting edges as they come from the sharpening process without requiring any further treatment such as hydrogen-stripping or electropolishing. Moreover, the oxides may be formed prior to, subsequent to or currently with the sintering of the fluorocarbon coating on the edges. In a preferred embodiment the cubic oxides are formed currently with the sintering step by carrying out such step in a limitedly oxidizing atmosphere.
• the sintering should preferably be carried out in a vacuum or in an inert atmosphere so as not to alter or remove the previously formed cubic oxide layer.
• the amount of oxygen present in such mixed atmospheres will generally be less than 100 p.p.m. and more particularly less cubic oxide layer may be of adequate thickness and be formed in a reasonable amount of time, it is preferable that the mixture contain at least about 0.5 p.p.m. of oxygen.
• the preferred range of oxygen in the mixture will lie between about 0.5 to about 50 p.p.m. and more particularly between about I to 25 p.p.m.
• the resulting blades may have a light brown to gold discoloration. Although such discoloration does of the blades, it may, in ceutzsirable from a purely 250 microns and more particularly less than about 125 microns.
• the preferredreduced pressure range when air is used will generally be between about 0.2 microns to 125 pressures will usually be about one-fifth of those for air.
• the reaction conditions are further dependent blade edges at temperatures between about 600 to 750 F. and more particularly between about 625 to 700 F. in periods of about 2 to minutes. Within theseconditions of time and temperature, it is usually advisable in carrying out the sintering and oxide-forming steps concurrently to use the lower oxygen pressures set forth above at the higher sintering temperatures and/or longer sintering times.
• the cubic oxide layer may be formed subsequent to the sintering steps by employing conditions such as those set forth above for carrying out the sintering and oxide-forming steps concurrently.
• the blades should usually be cooled to room temoxidizing or inert atmosphere before gases are nitrogen, argon, carbon dioxide and steam.
• gases are nitrogen, argon, carbon dioxide and steam.
• gases are not generally inert with respect to steel at all temperatures, but at the relatively low temperatures which are used to form the blade edges such gases act as if they were essentially inert and may be employed.
• the Illustrative useful reducing gases are hydrogen and cracked ammonia.
• the protective gas it would be expected because of the much larger amounts of it expectation, the cubic oxide layer can be suitably formed.
• oxidation can be made to overcome the reducing effect of reducing atmospheres such as hydrogen if sufiicient oxygen is present in the mixture. This amount of oxygen will vary with temperature. At about 650 F., the amount of oxygen will usually be, for example, at least about 15 p.p.m.
• the fluorocarbon polymers which are used in the present invention are solid, addition polymers comprising a plurality of CF,CF segments such as disclosed in the above mentioned US. Pat. No. 3,071,856.
• the preferred fluorocarbon polymers are those which comprise a preponderance of -CF CF segments such as polytetrafluoroethylene and copolymers tetrafluoroethylene with minor amounts e.g., 5 percent by weight of other monomers such as hexafluoropropylene.
• the molecular weight of the polymers may vary ranging, for example, from about 2,000 or even lower to above 2,000,000. Especially useful results were obtained polytetrafluoroethylene telomers such as disclosed in Irwin W.
• EXAMPLE I One hundred and twenty carbon steel blades were mechanically sharpened, cleaned in trichloroethylene and coated with Vydax 1000, a polytetrafluoroethylene Telomer sold by du- Pont. When the volatile vehicle of the coating composition had been evaporated, were placed in an all glass cassette within a glass chamber about 15 cu. in. in volume. The chamber was evacuated at room temperature to less than 50 millirnicrons H, pressure and a controlled air leak for producing 34 microns pressure in the chamber was set up and then isolated from the chamber by closing a valve. The chamber was again evacuated to a high vacuum, i.e., the millimicron range and the blades were brought to and maintained at a sintering temperature of about 640 F.
• Vydax 1000 a polytetrafluoroethylene Telomer sold by du- Pont.
• the cubic oxides which are formed on the blade edges in the processes of the present invention may be removed for study and identification, e.g., under the electron microscope, by methods such as disclosed in The Isolation and Examination of Films from Metal Surfaces; an Improved Technique by T. F. Norse and F. Wormwell, Journal of Applied Chemistry, Vol. 2, pp. 550-554 (1952).
• the fluorocarbon films may be removed prior to the cubic oxides by soaking the blades in a dispersion of sodium in naphthalene for about 30 minutes.
• a process as defined in claim 1 wherein said cubic iron oxide layer is in the range of about 50 to 800 Angstroms in thickness.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Metallurgy (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Wood Science & Technology (AREA)
• Thermal Sciences (AREA)
• Physics & Mathematics (AREA)
• Forests & Forestry (AREA)
• Physical Vapour Deposition (AREA)
• Other Surface Treatments For Metallic Materials (AREA)
• Dry Shavers And Clippers (AREA)
• Laminated Bodies (AREA)

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Publications (1)

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Family Applications (1)

Country Status (8)

Cited By (15)

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Citations (2)

• 1967
  • 1967-06-07 US US644052A patent/US3652342A/en not_active Expired - Lifetime
  • 1967-08-04 GB GB35836/67A patent/GB1165980A/en not_active Expired
  • 1967-08-18 BR BR192239/67A patent/BR6792239D0/pt unknown
  • 1967-08-22 DE DE19671553701 patent/DE1553701A1/de active Pending
  • 1967-08-24 NL NL6711633A patent/NL6711633A/xx unknown
  • 1967-08-30 BE BE703253D patent/BE703253A/xx unknown
  • 1967-08-31 ES ES344667A patent/ES344667A1/es not_active Expired
  • 1967-09-01 SE SE12170/67A patent/SE325801B/xx unknown

Patent Citations (2)

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