Patent Application
20080060201
The replaceable shaving system 10 shown in
While the shaving aid composite may have any desired shape, one preferred shape is shown in
The shaving aid composite 22 contains a water-soluble shaving aid and a water insoluble polymer and a shaving aid. The water-soluble shaving aid may be present only in the surface layer 30, or may be present in the entire upper portion 28, or the entire shaving aid composite. Different concentrations of the water-soluble shaving aid may be used in different portions of the shaving aid composite, e.g., a higher level may be used in surface layer 30 and a relatively lower level may be used in the rest of the shaving aid composite.
A water-soluble shaving aid is a substance that enhances shaving performance. It may, for example, improve shaving comfort (e.g., by lubricating the skin, improve shaving efficiency, condition the beard or other body hair, or condition the skin. Examples of shaving aids include lubricous water-soluble polymers such as polyethylene oxide, polyvinyl pyrrolidone, polyacrylamide, hydroxypropyl cellulose, polyvinyl imidazoline, and polyhydroxyethylmethacrylate.
At least a portion of the water-soluble shaving aid is coated, prior to incorporation into the shaving aid composite, with mineral oil. In some implementations, all of the water-soluble shaving aid is coated with mineral oil. In certain embodiments, the mineral oil is spray coated and such may be accomplished using conventional spray-coating process. In other embodiments, e.g., smaller scale production schemes, the mineral oil may be applied via a eye dropper while the water-soluble shaving aid is tumbled or agitated. The mineral oil may be included, for example, at a concentration of from about 0.5%, 1%, 1.5%, 2%, 3%, 3.5%, or 4% to about 4.5%, 6%, 7% 8%, 8.5%, 9%, or 10%, based on the total weight of the water-soluble shaving aid.
Suitable water-insoluble polymers which can be used include polyethylene, polypropylene, polystyrene, butadiene-styrene copolymer (e.g. medium and high impact polystyrene), polyacetal, acrylonitrile-butadiene-styrene copolymer, ethylene vinyl acetate copolymer and blends such as polypropylene/polystyrene blend.
The preferred lubricous water-soluble polymer is polyethylene oxide. The more preferred polyethylene oxides generally are known as POLYOX (available from Union Carbide Corporation) orALKOX (available from Meisei Chemical Works, Kyoto, Japan). These polyethylene oxides will preferably have molecular weights of about 100,000 to 6 million, most preferably about 300,000 to 5 million. The most preferred polyethylene oxide comprises a blend of about 40% to 80% of polyethylene oxide having an average molecular weight of about 5 million (e.g. POLYOX COAGULANT) and about 60% to 20% of polyethylene oxide having an average molecular weight of about 300,000 (e.g. POLYOX WSR-N-750). The polyethylene oxide blend may also advantageously contain up to about 10% by weight of a low molecular weight (i.e., MW<10,000) polyethylene glycol such as PEG-100. The polyethylene oxide may be provided, for example, in powder or pellet form.
Preferably, each portion includes about 5%, 15%, or 20% to about 35%, 40%, or 50% by weight of the water-insoluble polymer. The more preferred water-insoluble polymer is polystyrene, preferably a general purpose polystyrene such as BASF 2824 or a high impact polystyrene (i.e. polystyrene-butadiene), such as Mobil 4324. The portion should contain a sufficient quantity of water-insoluble polymer to provide adequate mechanical strength, both during production and use.
Enough shaving aid should be included to provide the desired benefit. A portion may contain, for example, about 20%, 30%, or 40% to about 75% or 80% by weight of a lubricous water soluble polymer. A portion also may include, for example, about 0.01% or 0.05% to about 1%, 1.5%, 2.5%, 5.0% vitamin E (or common forms of vitamin E) by weight.
The shaving aid may also contain other conventional shaving and composite ingredients, such as low molecular weight water-soluble release enhancing agents such as polyethylene glycol (e.g., 1-10% by weight), colorants, antioxidants and preservatives. Water-soluble release enhancing agents are described in U.S. Pat. No. 5,113,585, which is incorporated herein by reference. Portions that contain a colorant can be designed to release the colorant, and change color, during shaving, preferably in response to wear of the portion. A portion may contain, for example, between about 0.1%, 0.25%, or 0.5% and about 2%, 3%, or 5% colorant by weight.
The shaving aid composite 22 may be, for example, between about 30 mm, 31 mm, or 31.5 mm and about 32 mm, 32.5 mm, 33.5 mm, or 35 mm in length, and between about 1.5 mm or 1.75 mm and about 2 mm, 2.25 mm, 2.5 mm, or 3.0 mm in width at its widest portion (i.e., the widest portion of upper portion 28). The shaving aid composite may have an overall height, for example, of about 2 mm, 2.25, mm, 2.3 mm to about 2.3 mm, 2.35 mm, 2.45 mm, or 2.5 mm, measured along the longest distance between the bottom surface and top surface of the composite. When the shaving aid composite includes a surface layer 30, as shown in
The shaving aid composite may be fabricated by any appropriate method, including injection molding and extrusion, the latter being preferred. Any or all of the portions of the shaving aid composite may include the mineral oil coated water soluble shaving aid.
In some implementations, compositions for use in forming the shaving aid composite include (a) from about 5%, 15%, or 20% to about 35%, 40%, or 50% by weight of the water-insoluble polymer, (b) from about 20%, 30%, or 40% to about 75% or 80%, by weight of a lubricous water soluble polymer, and (c) about 0.5%, 2%, or 3.5% to about 4.5%, 6%, or 10% mineral oil, wherein the concentration of mineral oil is based on the total weight of the water-soluble shaving aid and the concentrations of the two polymers being based on the total weight of the composition. In some cases, the concentration of mineral oil based on the total weight of the composition (wt/wt basis) is in the range of about 0.1% to about 1.5%, e.g., about 0.12% to about 1.2%.
The shaving aid composites can be prepared by conventional coextrusion or molding methods known to those skilled in the art, as discussed in U.S. Pat. No. 5,956,848, the full disclosure of which is incorporated by reference herein. Once cooled, the composite can be cut to the appropriate length and attached to a razor cartridge or shaving system.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention.
For example, the shaving aid composite may be attached to the housing in any desired manner. For instance, the shaving aid composite may be mounted on the housing using an adhesive, rather than locking the shaving aid composite into an opening in the housing, as discussed above.
Moreover, the shaving aid composite may have any desired geometry and/or location. For example, the shaving aid composite may extend across the full width of a shaving system or razor cartridge, or only part of its width. Moreover, the composite need not be in the form of a straight strip that extends lengthwise. The shaving aid composite may have an arcuate shape, e.g., it may be in the form of a molded ring that surrounds the blades of an oval-shaped razor cartridge. Alternatively, the composite may be manufactured as an elongated strip and then positioned to surround the blades and clamped in place in an oval shape, e.g., as disclosed in U.S. Pat. No. 5,604,983, the full disclosure of which is incorporated herein by reference. The composite may be in other locations on the cartridge as desired.
The composite may also have any desired cross-sectional shape, for instance wedge-shaped, square or rectangular in cross-section. If the housing and composite do not include corresponding features for locking engagement, the composite may be glued to the housing or attached in any other desired manner, e.g., by insert molding.
As noted above, the shaving aid composite may be used on a wet shaving system that is a disposable shaving cartridge, or on a shaving head that is integral with a razor handle, e.g., on a disposable razor.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”.
All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. To the extent that any meaning or definition of a term in this written document conflicts with any meaning or definition of the term in a document incorporated by reference, the meaning or definition assigned to the term in this written document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
