Patent US5056221A successfully refreshed from Google Patents.
US5056221A
Expired / Lapsed
US
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Razor and process for manufacturing a surface of low frictional resistance on a razor
Assignee: Edgewell Personal Care Brands LLC
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Filing: 1990-12-14
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Granted: 1991-10-15
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Expires: 2010-12-14
Abstract
Abstract A razor blade unit comprising a support for at least one razor blade and a surface for slidably engaging the skin of a user, and a xerogel on the surface. A process for making a sliding surface on a razor blade unit comprising applying a solution of polyurethane, a water-soluble plastic and a solvent to a surface of the razor blade unit which engages the skin of a user during shaving, and evaporating the solvent to form the sliding surface.
Inventors
- 👤 Jochen Thoene
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:54
CPC Classifications
B; B26; B26B; B26B21/00; B26B21/54; B26B21/58; B26B21/60; A; A61; A61K; A61K8/00; A61K8/18; A61K8/72; A61K8/81; A61K8/817; A61K8/8176; A61K8/84; A61K8/87; A61Q; A61Q9/00; A61Q9/02; B26B21/40; B26B21/44; B26B21/443
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
60 words
A razor blade unit comprising a support for at least one razor blade, a surface for slidably engaging the skin of a user, and a xerogel on the surface, wherein the xerogel comprises a homogeneous mixture of homopolymers and copolymers of polyvinyl pyrrolidone with polyurethane in which the ratio of the amount of polyvinyl pyrrolidone to polyurethane is about (3-5):1.
Claim 2
Dependent Claim
60 words
A razor blade unit comprising a support for at least one razor blade, a surface for slidably engaging the skin of a user, and a xerogel on the surface, wherein the xerogel comprises a homogeneous mixture of homopolymers and copolymers of polyvinyl pyrrolidone with polyurethane in which the ratio of the amount of polyvinyl pyrrolidone to polyurethane is about (3-5):1.
Claim 3
Dependent Claim
24 words
The razor blade unit of claim 1, wherein the xerogel has a coefficient of friction less than 0.25 when contacted with a dispersion medium.
Claim 4
Dependent Claim
25 words
The razor blade unit of claim 1, wherein the xerogel has a coefficient of friction less than 0.25 when contacted with a hydrous dispersion medium.
Claim 5
Dependent Claim
14 words
The razor blade unit of claim 1, wherein the polyurethane is an aromatic polyurethane.
Claim 6
Dependent Claim
18 words
The razor blade unit of claim 1, wherein the ratio of polyvinyl pyrrolidone to polyurethane is about (3.6-4):1.
Claim 7
Dependent Claim
49 words
The razor blade unit of claim 1, wherein the polyurethane is a dispersion with water and N-methylpyrrolidone as a solvent, the polyurethane dispersion has a solids content between 30 and 33% by weight, the N-methyl pyrrolidone is from about 10 to 12% by weight and the balance is water.
Claim 8
Dependent Claim
26 words
The razor blade unit of claim 6, wherein the solids content of the polyurethane is 31% by weight and the N-methyl pyrrolidone is 11% by weight.
Claim 9
Dependent Claim
19 words
The razor blade unit of claim 1, including a cap and wherein the xerogel is disposed on the cap.
Claim 10
Dependent Claim
19 words
The razor blade unit of claim 8, wherein the xerogel is on a carrier film bonded to the cap.
Claim 11
Dependent Claim
19 words
The razor blade unit of claim 9, wherein the surface includes a recess where the carrier film is bonded.
Claim 12
Dependent Claim
38 words
The razor of claim 10, wherein the recess is a flat surface, and the front-end of the recess forms a rounded protective lip being about equivalent in height to the thickness of the carrier film and the xerogel.
Claim 13
Dependent Claim
25 words
The razor as in claim 10, wherein the xerogel and carrier film is angled forward from the plane of shaving to give increased skin contact.
Claim 14
Dependent Claim
19 words
The razor blade unit of claim 1, including a guardbar, and wherein the xerogel is disposed on the guardbar.
Claim 15
Dependent Claim
25 words
The razor blade unit of claim 1, including a cap and a guardbar, and wherein the xerogel is disposed on both the guardbar and cap.
Claim 16
Dependent Claim
23 words
The razor blade unit of claim 1, wherein the thickness of the xerogel is in the range of about 5 to 160 μm.
Claim 17
Dependent Claim
18 words
The razor blade unit of claim 1, wherein the thickness of the xerogel is less than 30 μm.
Claim 18
Dependent Claim
19 words
The razor blade unit of claim 1, wherein the xerogel is on a carrier film bonded to the surface.
Claim 19
Dependent Claim
19 words
The razor blade unit of claim 17, wherein the surface includes a recess where the carrier film is bonded.
Claim 20
Dependent Claim
14 words
The razor blade unit of claim 17, wherein the carrier film is polyvinyl chloride.
Claim 21
Dependent Claim
13 words
The razor blade unit of claim 17, wherein the carrier film is polyester.
Claim 22
Dependent Claim
14 words
The razor blade unit of claim 17, wherein the carrier film is polyethylene phthalate.
Claim 23
Dependent Claim
20 words
The razor blade unit of claim 17, wherein the carrier film is arranged on a flat portion of the cap.
Claim 24
Dependent Claim
27 words
The razor blade unit of claim 17, wherein the carrier film is arranged on a curved portion of the cap having a radius greater than 20 μm.
Claim 25
Dependent Claim
68 words
A process for making a sliding surface on a razor blade unit comprising forming a solution of polyurethane, polyvinyl pyrrolidone and a solvent, wherein the weight of polyvinyl pyrrolidone to polyurethane is in the range of about 3:1 to 5:1, evaporating the solvent to form a xerogel, and bonding the xerogel to a surface of the razor blade unit which engages the skin of a user during shaving.
Claim 26
Dependent Claim
68 words
A process for making a sliding surface on a razor blade unit comprising forming a solution of polyurethane, polyvinyl pyrrolidone and a solvent, wherein the weight of polyvinyl pyrrolidone to polyurethane is in the range of about 3:1 to 5:1, evaporating the solvent to form a xerogel, and bonding the xerogel to a surface of the razor blade unit which engages the skin of a user during shaving.
Claim 27
Dependent Claim
12 words
The process of claim 24, wherein the polyurethane is linear unlinked polyurethane.
Claim 28
Dependent Claim
17 words
The process of claim 24, wherein the forming step includes applying the solution to a carrier film.
Claim 29
Dependent Claim
12 words
The process of claim 26, wherein the carrier film is polyvinyl chloride.
Claim 30
Dependent Claim
11 words
The process of claim 26, wherein the carrier film is polyester.
Claim 31
Dependent Claim
12 words
The process of claim 26, wherein the carrier film is polyethylene phthalate.
Claim 32
Dependent Claim
19 words
The process of claim 26, including pretreating the carrier film with a bonding aid prior to the bonding step.
Claim 33
Dependent Claim
11 words
The process of claim 30, wherein the bonding aid is caustic.
Claim 34
Dependent Claim
12 words
The process of claim 31, wherein the bonding aid is a polymer.
Claim 35
Dependent Claim
20 words
The process of claim 24, including pretreating the surface of the razor blade unit in a solution of chromatisulphuric acid.
Claim 36
Dependent Claim
17 words
The process of claim 33, wherein the pretreating occurs for about 15 minutes at a raised temperature.
Claim 37
Dependent Claim
13 words
The process of claim 34, wherein the raised temperature is about 40° C.
Claim 38
Dependent Claim
17 words
The process of claim 24, wherein the solution is a homogeneous mixture of polyurethane and polyvinyl pyrrolidone.
Claim 39
Dependent Claim
16 words
The process of claim 36, including the step of constantly stirring the solution to ensure homogeneity.
Claim 40
Dependent Claim
28 words
The process of claim 24, wherein the evaporating step is carried out at a temperature of greater than 70° C. for a time of less than 15 minutes.
Claim 41
Dependent Claim
67 words
A process for making a sliding surface on a razor blade unit comprising applying a solution of polyurethane and polyvinyl pyrrolidone and a solvent to a surface of the razor blade unit which engages the skin of a user during shaving, wherein the weight of a polyvinyl pyrrolidone to polyurethane is in the range of about 3:1 to 5:1, and evaporating the solvent to form a xerogel.
Claim 42
Dependent Claim
67 words
A process for making a sliding surface on a razor blade unit comprising applying a solution of polyurethane and polyvinyl pyrrolidone and a solvent to a surface of the razor blade unit which engages the skin of a user during shaving, wherein the weight of a polyvinyl pyrrolidone to polyurethane is in the range of about 3:1 to 5:1, and evaporating the solvent to form a xerogel.
Claim 43
Dependent Claim
12 words
The process of claim 39, wherein the polyurethane is linear unlinked polyurethane.
Claim 44
Dependent Claim
22 words
The process of claim 39, including pretreating the surface of the razor blade unit with a primer prior to the applying step.
Claim 45
Dependent Claim
17 words
The process of claim 39, wherein the solution is a homogeneous mixture of polyurethane and polyvinyl pyrrolidone.
Claim 46
Dependent Claim
16 words
The process of claim 42, including the step of constantly stirring the solution to ensure homogeneity.
Claim 47
Dependent Claim
28 words
The process of claim 39, wherein the evaporating step is carried out at a temperature of greater than 70° C. for a time of less than 15 minutes.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-10-14 | 1995-04-15 | 1995-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-14 | 1999-04-15 | 1999-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-14 | 2003-04-15 | 2003-10-15 | $7700.00 | Window Closed / Lapsed |