Classifications

• • 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
  • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
  • B05D3/04—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases
• • 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
  • C09D123/00—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers
  • C09D123/26—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers modified by chemical after-treatment
  • C09D123/28—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers modified by chemical after-treatment by reaction with halogens or compounds containing halogen
• • 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
  • 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
  • C09D127/02—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 not modified by chemical after-treatment
  • C09D127/12—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 not modified by chemical after-treatment containing fluorine atoms
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S128/00—Surgery
  • Y10S128/14—Polytetrafluoroethylene, i.e. PTFE

Definitions

• razor blades of steel i.e., either carbon steel or stainless steel, to which there has been applied, at least in the vicinity of the cutting edge thereof, a thin adhering coating or film of a lubricant or abhesive material whereby the shaving properties of the blade are improved by reducing friction between the cutting instrument and the face and beard of the shaver.
• the solid fluorocarbon polymer is applied to the blade as a suspension or dispersion in a volatile liquid medium, e.g., water or an organic solvent, as by dipping the edges of the blade into the suspension or by brushing or spraying the suspension onto the blades; the coating thus deposited then being dried by evaporating the liquid medium and the blades baked at an elevated temperature to fuse the solid fluorocarbon particles and form an adhering thin film.
• a volatile liquid medium e.g., water or an organic solvent
• the baking operation is carried on at temperatures ranging from about 200 F to about 750 F. in an oxidizing or neutral atmosphere.
• Such proposals have been disclosed, for instance, in French Patents 1,299,519 and 1,293,388.
• Teflon is an excellent abhesive material. In other words, it has a strongly developed tendency to adhere to nothing and to prevent other things from adhering to it, a property commonly known as release or abhesiveness. Consequently, much attention has been given to ways and means of causing such fluorocarbons to bond with a metal surface to form a strongly-adhering thin film thereon. Though baking, as decribed above, has been resorted to for accomplishing this purpose, numerous difliculties have been encountered in its practical application for the production of uniformly superior razor blades at commercial production rates.
• the present invention is predicated on our discovery that the objections and difliculties heretofore encountered in treating razor blades in accordance with the disclosures of the previously noted French patents may be overcome and a high yield of fluorocarbon-coated razor blades of improved and highly uniform quality obtained by carrying out the baking, bonding or sintering phase in a re- 3,203,829 Patented Aug. 31, 1965 ducing atmosphere, such as an atmosphere which is predominantly hydrogen, and that especially advantageous results may be obtained where the reducing atmosphere is composed primarily of hydrogen and nitrogen, advantageously a reducing atmosphere such as results from the thermal dissociation of ammonia consisting primarily of hydrogen and nitrogen and containing a minor proportion of undecomposed ammonia.
• the invention in its broader aspect, is applicable to the bonding of thin films of various fluorocarbons to razor blades of either carbon steel or stainless steel, for instance, fluorocarbons such as polytetrafluoror ethylene, i.e., Teflon, or polytrifluorochloroethylene, fluoronated ethylenepropylene or the like.
• fluorocarbons such as polytetrafluoror ethylene, i.e., Teflon, or polytrifluorochloroethylene, fluoronated ethylenepropylene or the like.
• Teflon polytetrafluoror ethylene
• polytrifluorochloroethylene fluoronated ethylenepropylene or the like.
• it has been used, with particlar advantage, in applying to razor blades thin adhering coatings of Teflon.
• It is applicable to various baking conditions of time and temperature, as noted, for instance, in the aforesaid French patents, optimum time and temperature conditions being interdependent.
• the baking temperature may range from 300 F., or somewhat lower, to about 750 F., due consideration being given to danger of deleteriously affecting razor blade steel by extended periods of high temperature, as well understood in the art.
• the fluorocarbon is applied to the razor blade, as by dipping, coating or spraying, as a suspension or dispersion thereof in a volatile liquid medium and the applied coating should be Well dried by evaporation of the liquid medium prior to subjecting the blade to the baking step, so as to avoid contaminating the reducing atmosphere.
• the liquid medium one may use water or an organic solvent, as has been previously proposed.
• the razor blades will have been carefully sharpened and cleaned prior to the application of the coating thereto and We have found that one of the primary problems involved is the retention of the sharpness of the edges during the treatment.
• the sharpened razor blades may be deleteriously affected by even a minute amount of oxidation during the baking operation. Damage to the razor blades due to such oxidation is entirely avoided where the baking step is carried on in a reducing atmosphere, in accordance with this invention.
• a stronger, more uniform and more lasting adhesion of the coatings to the blade is obtained and the blades so produced have been found to have more uniformly superior shaving quality than those heretofore available.
• the reducing atmosphere maintained during the baking operation tends to reduce and remove any oxide film present on the facets or bevels forming the cutting edge which, in turn, promotes tighter and more uniform bonding of the fluorocarbon to those surfaces, as well as entirely inhibiting any corrosion, etching or oxidizing of those surfaces. Further, the reducing atmosphere tends to remove the effects of any oils or other organic matter retained on those surfaces, thus further assuring a tighter bonding of the film to the steel Without any contaminating influences of such oils or other organic materials. Thus, a more durable film of the lubricating material on the blade edges is obtained.
• the ground and sharpened safety razor blades are first assembled in quantities of approximately 1000 to 2000 in a bayonet-type fixture or holder and the blades cleaned,
• the concentration of the dispersion may be about 1 part, by weight, of the polymer to 9 parts of water.
• the blades with the coating thereon are then heated to a temperature of about 635660 F. in an atmosphere of dissociated ammonia, the atmosphere being supplied to the treating chamber at a rate equivalent to about 5 cubic feet of hydrogen (S.T.P.) per hour per 1000 blades.
• This heating cycle is continued for 20 to 30 minutes and thereafter the blades are held at a temperature in excess of 630 F., for instance 650 F., for from 5 to 8 minutes.
• the blades are then cooled to about 500 F. while still under reducing atmosphere and are then cooled to about F.
• an inert atmosphere e.g., nitrogen, may be used.
• further cooling may be effected by compressed air.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Forests & Forestry (AREA)
• Mechanical Engineering (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Knives (AREA)

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22847848

Family Applications (1)

Country Status (3)

Cited By (20)

Citations (3)

• 1962
  • 1962-09-25 US US226169A patent/US3203829A/en not_active Expired - Lifetime
• 1963
  • 1963-06-21 GB GB24837/63A patent/GB964956A/en not_active Expired
  • 1963-08-02 DK DK371463AA patent/DK107012C/da active

Patent Citations (3)

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