Razor blade technology

• US 5,669,144 A
• Filed: 11/07/1995
• Issued: 09/23/1997
• Est. Priority Date: 11/15/1991
• Status: Expired due to Term

• Current Assignee: Gillette Company (The Procter & Gamble Company)
• Original Assignee: Gillette Company (The Procter & Gamble Company)
• Inventors: Madeira, John, Hahn, Steve Syng-Hi, Chou, Chong-ping Peter, Brooks, Lamar Eugene
• Primary Examiner(s): PAYER, HWEI SIU CHOU
• Application Number:
  US08/554,798
• Time in Patent Office: 686 Days
• Field of Search: 30/50, 30/346.53, 30/346.54, 30/346.55, 30/350, 204/192.3, 76/104.1, 76/116, 76/DIG. 8
• US Class Current: 30/346.54
• CPC Class Codes: B26B 21/60 by the coating material

Abstract

A razor blade includes a substrate with a wedge-shaped edge at a distance of forty micrometers from the sharpened tip, and a layer of diamond or diamond-like material defined by facets that have an included angle of less than seventeen degrees that has 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, 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.

Claims

1. 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,

a layer of interlayer material on the tip and flanks of said wedge-shaped edge, the thickness of said interlayer material being in the range of about 50-500 angstroms, and a layer of diamond or diamond-like carbon material on said interlayer material, said layer of diamond or diamond-like carbon material having a thickness in the range of twelve hundred to eighteen 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, 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, a hardness of at least thirteen gigapascals and an L5 wet wool felt cutter force of less than 0.8 kilogram, and dry wool felt (ten cuts) edge damage of less than fifty small edge damage regions and no damage regions of larger dimension or depth.

2. The razor blade of claim 1 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.

3. 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, a layer of niobium on the tip and flanks of said wedge-shaped edge, the thickness of said niobium layer being in the range of about 50-500 angstroms, and a layer of diamond or diamond-like carbon material on said niobium layer, said layer of diamond or diamond-like carbon material having a thickness in the range of twelve hundred to eighteen 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, 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, a hardness of at least thirteen gigapascals and an L5 wet wool felt cutter force of less than 0.8 kilogram, and dry wool felt (ten cuts) edge damage of less than fifty small edge damage regions and no damage regions of larger dimension or depth.

4. The razor blade of claim 3 wherein said substrate is steel;

said wedge-shaped edge is formed by a sequence of mechanical abrading steps; and

said layers of niobium and diamond or diamond-like carbon material are formed by sputtering.

5. The razor blade of claim 4 wherein said layer of diamond or diamond-like carbon (DLC) material has 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.

6. A shaving unit comprising support structure that defines spaced skin-engaging surfaces, and razor blade structure secured to said support structure, said razor blade structure including 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 diamond or diamond-like carbon material on said wedge-shaped edge, said layer of diamond or diamond-like material having a thickness in the range of twelve hundred to eighteen 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, a hardness of at least thirteen gigapascals, an L5 wet wool felt cutter force of less than 0.8 kilogram, and dry wool felt (ten cuts) edge damage of less than fifty small edge damage regions and no damage regions of larger dimension or depth, said diamond or diamond-like carbon coated wedge-shaped edge being disposed between said skin-engaging surfaces.

7. The shaving unit of claim 6 wherein said razor blade structure includes two substrates, and said coated wedge-shaped edges are disposed parallel to one another between said skin-engaging surfaces.

8. The shaving unit of claim 7 wherein each said layer of diamond or diamond-like carbon material has substantial sp3 carbon bonding;

a mass density greater than 1.5 grams/cm³ ; and

a Raman peak at about 1331 cm^-1 (diamond) or 1550 cm^-1 (DLC); and

further including an adherent polymer coating on each said layer of diamond or diamond-like carbon material.

9. 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, a hardness of at least thirteen gigapascals, an L5 wet wool felt cutter force of less than 0.8 kilogram, dry wool felt (ten cuts) edge damage of less than ten 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.

10. The razor blade of claim 9 wherein said layer of strengthening material is diamond or diamond-like carbon (DLC) material and has a Raman peak at about 1331 cm^-1 (diamond) or about 1550 cm^-1 (DLC).

11. The razor blade of claim 10 wherein said layer of diamond or diamond-like carbon (DLC) has substantial sp3 carbon bonding;

and a mass density greater than 1.5 grams/cm³.

12. The razor blade of claim 10 and further including a layer of niobium on said wedge-shaped edge;

said niobium layer having a thickness of less than about five hundred angstroms; and

said diamond or DLC coating on said cutting edge has a thickness in the range of twelve hundred to eighteen hundred angstroms.

13. The razor blade of claim 9 and further including an adherent polymer coating on said layer of strengthening material.

14. The razor blade of claim 9 and further including a layer of molybdenum on said wedge-shaped edge;

said molybdenum layer having a thickness of less than about five hundred angstroms.

15. 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 a sharpened tip and an included angle of less than seventeen degrees at a distance of forty micrometers from the tip of said sharpened tip and a edge radius of less than four hundred angstroms;

and

sputter depositing a layer of diamond or diamond-like carbon material on said sharpened edge;

said layer of diamond or diamond-like carbon material 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, 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.

16. The process of claim 15 wherein said substrate is mechanically abraded in a sequence of honing steps to form said sharpened edge.

17. The process of claim 15 and further including the step of applying an adherent polymer coating on said diamond or diamond-like carbon coated sharpened edge.

18. The process of claim 15 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.

19. The process of claim 18 wherein said molybdenum layer on said sharpened edge has a thickness of less than about five hundred angstroms.

20. The process of claim 15 and further including the step of

depositing a layer of niobium on said sharpened edge;

and

said layer of diamond or diamond-like carbon material is deposited on said niobium layer.

21. The process of claim 20 wherein said niobium layer on said cutting edge has a thickness of less than about five hundred angstroms.

22. The process of claim 15 wherein said substrate is of metal and said diamond or diamond-like carbon layer is at least twice as hard as said metal substrate.

23. The process of claim 15 wherein said layer of diamond or diamond-like material is deposited in an argon atmosphere in an evacuated chamber in which a graphite target and a shutter are located;

said graphite target is energized; and

said shutter is opened to deposit said layer of diamond or diamond-like material on said sharpened edge while an RF bias is applied to said substrate.

24. The process of claim 23 and further including a molybdenum target in said chamber, and further including the step of depositing a molybdenum layer on said sharpened edge.

25. The process of claim 23 and further including a niobium target in said chamber, and further including the step of depositing a niobium layer on said sharpened edge.

26. A process for forming a razor blade comprising the steps of

providing a substrate,

forming on said substrate a wedge-shaped edge that has a sharpened tip and an included angle of less than seventeen degrees at a distance of forty micrometers from the sharpened tip and a tip radius less than 400 angstroms;

and

disposing said substrate and a solid target member in a chamber; and

sputtering said solid target member to generate carbon atoms for forming a diamond or diamond-like carbon layer on said wedge-shaped edge to provide 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, 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.

27. The process of claim 26 wherein said layer of diamond or diamond-like material is deposited in an argon atmosphere in an evacuated chamber in which a graphite target and a shutter are located;

said graphite target is energized; and

said shutter is opened to deposit said layer of diamond or diamond-like material on said sharpened edge.

28. The process of claim 26 wherein said diamond or diamond-like carbon layer on said cutting edge has a thickness in the range of twelve hundred to eighteen hundred angstroms.

29. The process of claim 28 and further including the step of applying an adherent polymer coating on said diamond or diamond-like carbon coated cutting edge.