Process for making a hydrophilic coating on a formed part and safety razor made using this process
AssigneeWilkinson Sword Limited
InventorHelmut Ritter
Life of this patent
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Abstract
Process for forming and applying a hydrophilic coating, which is highly slideable when wet, to a plastic or metal part either directly, or indirectly via plastic film, to a safety razor or razor blade unit, in which a solution containing a water-soluble polymer is applied to the plastic or metal part and is cured. The invention also relates to a razor blade unit comprising a blade platform for at least one razor blade, a surface for slidably engaging the skin of a user and a coating on the surface for increasing the slideability of the surface. The coating comprises a water-soluble polymer or copolymer of poly-N-vinylpyrrolidone, at least one radically polymerizable vinyl monomer and a photoinitiator.
Claims15
The razor blade unit of claim 15, wherein the coating on the surface is cured.
The razor blade unit of claim 15, wherein the poly-N-vinylpyrrolidone is present an amount ranging from about 0.1 to 90% by weight.
The razor blade unit of claim 15, wherein the mean molecular weight of the poly-N-vinylpyrrolidone is from about 200,000 to 500,000 g/mol.
The razor blade unit of claim 15, wherein the vinyl monomer is an acrylic acid, a methylacrylic acid or a derivative thereof.
The razor blade unit of claim 15, wherein the vinyl monomer is a mixture of acrylic acid derivatives with N-vinylpyrrolidone or a mixture of polyester resins containing styrene and maleic or fumaric acid.
The razor blade unit of claim 15, wherein the vinyl monomer is a urethane modified acrylic or methacrylic ester.
The razor blade unit of claim 15, wherein the photoinitiator is present in an amount ranging from about 0.01 to 5% by weight.
The razor blade unit of claim 15, wherein the photoinitiator is present in an amount ranging from about 0.3 to 5% by weight.
The razor blade unit of claim 15, wherein the coating further comprises a multi-functional vinyl compound which is present in an amount up to 50% by weight.
The razor blade unit of claim 15, wherein the coating further comprises a photoactivator present in an amount ranging from about 0.3 to 5% by weight.
The razor blade unit of claim 15, wherein the photoactivator is a mercaptoacetic acid, an organic amine, or a mixture thereof.
A razor blade unit comprising a blade platform for at least one razor blade, a surface for slidably engaging the skin of a user, and a coating on the surface for increasing the slidability of the surface, wherein said coating comprises a water-soluble polymer or copolymer of poly-N-vinylpyrrolidone, at least one radically polymerizable vinyl monomer and a photoinitiator.
Dependencies are inferred from the claim text.