Razor blades and razors

Abstract

Razors are described herein. In some instances the razors include a safety razor blade unit comprising a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap. A first blade defines a blade edge nearer the guard and a second blade defines a blade edge nearer the cap. The first blade has a cutter force greater than the cutter force of the second blade. In some instances the razors provide a comfortable shave having improved closeness.

Description

DESCRIPTION OF DRAWINGS

FIGS. 1 a-c represent a schematic diagram depicting the cutting of a hair extended from a hair follicle.

FIGS. 2, 3a-b, 4, and 5a-c depict razors having multiple blades where one or more blades have relatively higher cutter forces than another blade positioned in the razor.

FIG. 6 depicts a schematic of a plasma formation process.

FIGS. 7 a and 7b depict modification of a portion of a blade using plasma.

FIG. 8 depicts an atomic force microscope (AFM) image of a blade tip etched with plasma.

Claims

1. A razor comprising: a safety razor blade unit comprising a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap, a first blade defining a blade edge nearer the guard and a second blade defining a blade edge nearer the cap, wherein the first blade has a cutter force greater than the cutter force of the second blade.

2. The razor of claim 1 wherein the first blade has a cutter force at least about 0.1 lbs. greater than the cutter force of the second blade.

3. The razor of claim 1 wherein the first blade has a cutter force at least about 0.2 lbs. greater than the cutter force of the second blade.

4. The razor of claim 2 wherein the first blade has a cutter force from about 0.1 lbs. to about 1.0 lbs. greater than the cutter force of the second blade

5. The razor of claim 4 wherein the first blade has a cutter force from about 0.1 lbs. to about 0.5 lbs. greater than the cutter force of the second blade.

6. The razor of claim 5 wherein the first blade has a cutter force from about 0.2 lbs. to about 0.3 lbs. greater than the cutter force of the second blade.

7. The razor of claim 1, wherein the cutter force of the first blade is between about 1.2 lbs and 1.5 lbs.

8. The razor of claim 1 wherein the blades are coated with a polymer composition.

9. The razor of claim 8 wherein the polymer composition is polyfluorocarbon.

10. The razor of claim 9 wherein the polyfluorocarbon is polytetrafluoroethylene.

11. The razor of claim 8 wherein the second blade is coated with a greater amount of polymer composition than the first blade.

12. The razor of claim 8 wherein the first blade and the second blade are coated with different polymer compositions.

13. The razor of claim 12 wherein the polymer composition coating the first blade is less lubricious than the polymer composition coating the second blade.

14. The razor of claim 1 wherein the first blade is substantially free of polymer coating.

15. The razor of claim 1 comprising three blades with parallel sharpened edges.

16. The razor of claim 15 wherein the first blade is the blade nearest to the guard.

17. The razor of claim 15 wherein the first blade is not the blade nearest to the guard.

18. The razor of claim 15 comprising four blades with parallel sharpened edges.

19. The razor of claim 18 wherein the first blade is the blade nearest to the guard.

20. The razor of claim 18 wherein the first blade is not the blade nearest to the guard.

21. The razor of claim 18 comprising five blades with parallel sharpened edges.

22. The razor of claim 21 wherein the first blade is the blade nearest to the guard.

23. The razor of claim 21 wherein the first blade is not the blade nearest to the guard.

24. A razor comprising: a safety razor blade unit comprising a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap, a first blade defining a blade edge nearer the guard and a second blade defining a blade edge nearer the cap, wherein the second blade is coated with a greater amount of a polymer composition than the first blade.

25. The razor of claim 24 wherein the first blade is substantially free of polymer composition.

26. The razor of claim 24 wherein the polymer composition is polyfluorocarbon.

27. The razor of claim 26 wherein the polyfluorocarbon is polytetrafluoroethylene.

28. The method of claim 24 wherein both the first and second blades are coated with a polymer.

29. The razor of claim 28 wherein the first and second blades are coated with different polymer compositions.

30. The razor of claim 29 wherein the polymer composition on the first blade is less lubricious than the polymer composition on the second blade.

31. The razor of claim 24 comprising three blades with parallel sharpened edges.

32. The razor of claim 31 comprising four blades with parallel sharpened edges.

33. The razor of claim 32 comprising five blades with parallel sharpened edges.

34. The razor of claim 31, 32 or 33 wherein the first blade is not the blade nearest to the guard.

35. A razor comprising: a safety razor blade unit comprising a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap, a first blade defining a blade edge nearer the guard and a second blade defining a blade edge nearer the cap, wherein the first and second blades comprise a polymer coating and the polymer coating on the first blade is less lubricious than the polymer coating on the second blade.

36. The razor of claim 35 comprising three blades with parallel sharpened edges.

37. The razor of claim 36 comprising four blades with parallel sharpened edges.

38. The razor of claim 37 comprising five blades with parallel sharpened edges.

39. The razor of claim 36, 37 or 38 wherein the first blade is not the blade nearest to the guard.

40. A method of treating a razor blade comprising; disposing a polymer coating on a razor blade; andexposing the coated razor blade to plasma, laser, or electric current, thereby modifying at least a portion of the polymer coating.

41. The method of claim 40 comprising exposing the blade to plasma.

42. The method of claim 41 wherein the plasma is radiofrequency plasma.

43. The method of claim 41 wherein the plasma is direct current plasma.

44. The method of claim 41 wherein the plasma comprises at least one of oxygen, argon, nitrogen, fluorine, or a fluorocarbon.

45. The method of claim 41 wherein the plasma comprises argon.

46. The method of claim 45 wherein the plasma comprises a mixture of argon and oxygen.

47. The method of claim 46 wherein the plasma comprises a mixture of about 90% argon and about 10% oxygen.

48. The method of claim 40 wherein the coated blade is exposed to plasma for between about 5 seconds and about 10 minutes.

49. The method of claim 40 wherein the plasma is delivered at a power between about 3 watts and about 100 watts.

50. The method of claim 41 comprising exposing the blade to plasma under vacuum.

51. The method of claim 50 wherein the vacuum pressure is between about 1 mtorr and about 100 mtorr.

52. The method of claim 51 wherein the vacuum pressure is between about 10 mtorr and about 50 mtorr.

53. The method of claim 52 wherein the vacuum pressure is between about 20 mtorr and about 40 mtorr.

54. The method of claim 40 wherein a portion of the polymer coating is physically modified.

55. The method of claim 30 further comprising treating the coated razor blade with a solvent.

56. The method of claim 55 wherein the coated razor blade is treated with the solvent before exposing the coated razor blade to plasma, laser, or electric current.

57. The method of claim 55 wherein the coated blade is treated with the solvent after exposing the coated razor blade to plasma, laser, or electric current.

58. The method of claim 40 wherein the polymer coating is disposed on the razor blade by spraying the polymer on the blade and sintering the razor blade.

59. The method of claim 40 wherein the polymer coating is disposed on the razor blade by chemical vapor deposition, or laser or sputtering deposition.

60. A method of making a razor comprising a safety razor blade unit comprising a guard, a cap, and at least two blades having parallel sharpened edges located between the guard and cap, a first blade defining a blade edge nearer the guard and a second blade defining a blade edge nearer the cap, the method comprising; treating the first or second blade to provide the second blade with a lower cutter force than the first blade.

61. The method of claim 60 wherein the second blade is treated with a polymer coating and the first blade is not.

62. The method of claim 60 comprising coating the first and second blades with a polymer coating and masking at least a portion the first blade.

63. The method of claim 60 comprising coating the first and second blades with polymer coating and subsequently removing at least a portion of the polymer coating from the first blade.

64. The method of claim 63 wherein at least a portion of the polymer coating is removed from the first blade with plasma etching.

65. The method of claim 60 comprising coating the first and second blades with polymer coating wherein the polymer coating of the first blade is less lubricious than the polymer coating of the second blade.

66. A method of shaving comprising: providing a safety razor blade unit comprising a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap, a first blade defining a blade edge nearer the guard and a second blade defining a blade edge nearer the cap, wherein the first blade has a cutter force greater than the cutter force of the second blade; andcontacting a skin surface with the safety razor blade unit.

67. A method of shaving comprising: a safety razor blade unit comprising a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap, a first blade defining a blade edge nearer the guard and a second blade defining a blade edge nearer the cap, wherein the second blade is coated with a greater amount of a polymer composition than the first blade; andcontacting a skin surface with the safety razor blade unit.