The invention concerns an applicator for dipping into a cosmetic preparation and for application thereof to the skin, semi-mucous membrane, mucous membrane, little hairs or hairs; hereinafter also referred to as a dip or wand applicator.
Basically all kinds of liquid, pasty, gel-like or powder substances can be considered as the cosmetic preparation. The applicator which is designed for that purpose is intended to be suitable for achieving uniform application and distribution of the preparation as far as possible at the same time over a relatively large region and to various parts of the skin or hair.
Dip or wand applicators are known in the cosmetic industry for example in the form of mascara brushes, large brushes, fine brushes, foam sponges or foam rubber applicators, for example for applying eyelash or hair mascara, liquid lipstick of high viscosity or the like.
The applicators which are in the form of small or large brushes are generally formed by glueing or mechanically fixing the bristles or hairs to a stick-like holding portion. Flock-coated dip or wand applicators are also known, for example for applying powder eyeshadow or the like. The flock coating is achieved by flocks which are applied to the surface of the applicator electrostatically being glued thereto.
In that production process however microbial pollution and a production duration which is relatively long in dependence on the drying time of the adhesive are found to be problems. It has further been found that application and distribution of the cosmetic preparation does not always occur uniformly, because of the statistical distribution of the flocks on the surface. That problem is even worsened with an increasing duration of use because the flocks have a tendency to stick together, in dependence on the nature of the cosmetic preparation. A similar consideration applies in regard to brush-like applicators.
U.S. Pat. No. 6,616,366 discloses another applicator brush for applying mascara, which can be produced by means of a two-component injection molding process (2-C process). That procedure involves injection molding on a holding portion which is in the form of a stiff plastic core, radially projecting bristles which comprise a softer plastic material (applicator portion). The working procedure involved in the injection molding operation is implemented at elevated temperatures, generally in the region of 200° C. or above. Such a temperature is fatal for micro-organisms and the applicator produced therefore leaves the injection molding machine in a germ-free condition. If the applicator is produced completely in one machine in that way in a plurality of successive injection molding operations, the problem of microbial pollution will be overcome. The stiffness of the bristles can also be adjusted by suitable selection of the plastic material so that they can be prevented from sticking together.
In some of the embodiments of the mascara brushes of U.S. Pat. No. 6,616,366 the holding portion has over its entire length an axial passage in which cosmetic preparation is deposited and guided. The bristles in turn have inner capillaries which are connected to that passage and through which the cosmetic preparation can issue at the surface of the bristles. In that way, when applying cosmetic preparation, the brush can be supplied with cosmetic preparation. That permits more uniform delivery over a prolonged period of time, until the preparation which is deposited in the cavity is used up. It could turn out however that this arrangement suffers from the disadvantage that the capillaries within the bristles easily clog up so that the feed duct is not equally suitable for every kind of preparation. In addition, the production of such brushes is complicated and correspondingly costly, in particular by virtue of the provision of capillaries in each of the bristles.
The object of the invention is to provide an applicator which is suitable for the application of a large number of different cosmetic substances to the skin, semi-mucous membrane, mucous membrane or to tiny hairs and which is favorable in terms of production.
That object is attained by an applicator of the kind set forth in the opening part of this specification comprising a holding portion and an applicator portion which is injection molded on to the holding portion, wherein both the holding portion and also the applicator portion at least partially comprise plastic material and the plastic material of the holding portion is harder than the plastic material of the applicator portion and wherein on its outside surface the applicator portion has at least one passage which extends substantially over the entire length of the applicator portion and which is adapted to distribute the cosmetic substance in the direction of lengthwise extent of the applicator portion.
The dip or wand applicators according to the invention can be offered as a product together with a bottle in which the cosmetic preparation is stored and into which the applicator is dipped, in which respect the applicator can have a haptic which at the same time forms the (screw) closure of the bottle. In a somewhat different configuration the applicators according to the invention can also be stored in a case or other container and/or provided with a protective cap or enclosed with the cosmetic product.
The formation of the passage on the outside surface of the applicator portion is simple from the production engineering point of view by virtue of using a suitable injection molding mold for the applicator portion. Dimensioning of the passage is advantageously effected having regard to the physical properties of the cosmetic preparation and the interaction with the plastic material of the applicator portion, in particular surface tension and wetting. In that case the applicator and the preparation form a system in respect of which it is successfully possible to distribute the cosmetic preparation through the capillary nature of the passage effectively in the direction of the lengthwise extent of the applicator portion, in a structurally simple fashion.
In addition the holding portion of the applicator according to the invention affords an adjusting option in terms of its inherent stability insofar as it extends at least partially into the applicator portion in the direction of lengthwise extent of the applicator. Finally, the choice of a suitable softer plastic material for the applicator portion means that it is possible to set the desired touch, entrainment and distribution properties, having regard to wetting which is also dependent on the preparation, for the respective situation of use.
In an advantageous development the passage is of a width which varies over its length. In that way the capillarity thereof can be varied in given regions. Regions of increased capillarity then serve predominantly for the transport action while those of lower capillarity serve at the same time as a depository means for the cosmetic preparation to be applied.
Good conveyance of the preparation is preferably achieved if the width of the passage is approximately equal to the depth thereof with respect to the outside surface of the applicator portion. The passage is also preferably narrowed with increasing depth.
To provide a short transport path for the cosmetic preparation it is advantageous if the passage extends substantially in the direction of lengthwise extent of the applicator portion.
In a further preferred embodiment the passage describes at least one spiral winding around the applicator portion. In that way the preparation is conveyed not only axially with respect to the direction of lengthwise extent of the applicator portion but also angularly, that is to say distributed radially over the periphery thereof.
It is advantageous if the cross-section of the passage decreases or tapers towards the end of the applicator portion, which is remote from the holding portion, in particular insofar as the depth and the width of the passage decrease approximately equally towards the end of the applicator portion, which is remote from the holding portion. That provides that the capillarity in that region is increased and the tip of the applicator portion which is preferably used for applying the preparation is supplied with sufficient cosmetic substance.
Instead of or in addition to the varying width of the passage the passage is advantageously interrupted by at least one depository means. The depository means is preferably formed by a channel or groove extending around the applicator portion substantially transversely with respect to the direction of lengthwise extent thereof. In that respect the depository means and the passage are preferably of the same depth with respect to the outside surface of the applicator portion. With an adequate dimension (width) such a depository means can accommodate more cosmetic preparation than the passage in order to supply same, in which respect the uniform depth provides that no depression is formed, in which the preparation is left behind.
In accordance with a further preferred embodiment the touch properties and the distribution properties can be improved if the applicator portion has a surface structure with a plurality of structure elements. Depending on the respective ergonomy of the entire applicator and depending on the respective application use as well as the cosmetic preparation to be applied the surface structure in that case can have a preferred direction. It is possible in that way to provide for various effects such as for example a velour effect and different entrainment properties for the cosmetic preparation. That provides for improved distribution and/or blending of the cosmetic preparation with at the same time a more pleasant sensation during contact with the skin.
Depending on the respective use involved various geometrical arrangements and dimensions of knobs, lines, grooves, bars, waves, honeycombs, bowls, crowns or other erosion, knurling or milling structures are to be preferred as the surface structures of the applicator portion. They can be of a regular or irregular configuration. Thus, ranging from those with a closed surface to those with an open-pore surface such as for example on a foam applicator, it is possible to simulate a large number of applicators.
The geometrical configuration of the applicator portion in itself can also be designed in many different ways, for example wedge-shaped, spherically curved, cylindrical, with or without (flat) application surfaces (flattenings), with ball segments, in the shape of a projectile or tapered in the form of a cone towards the tip, or of other designer shapes, depending on respective ergonomy and design aspects.
The process for the production of such an applicator provides that, in the two-component injection molding process, the applicator portion is injection molded in the direction of the lengthwise extent of the applicator to the holding portion by means of an injection molding machine, or is entirely or partially injected therearound, so that the holding portion forms a hard core of individually adapted extent. By virtue thereof, and due to the choice of the plastic material for the applicator portion, the degree of flexibility of the applicator portion can be freely adjusted without making the production process fundamentally more difficult. In addition the disadvantages of complicated and expensive production and microbial contamination do not occur as, as mentioned above, the operation of injecting the plastic material for the applicator portion takes place under conditions which are fatal to micro-organisms.
In that respect it is not crucial that the holding portion is produced completely from the holding portion plastic material in the preceding injection molding operation, or consists entirely of plastic material. Equally, prior to injection of the holding portion, at least one insert portion for example of metal, wood or thermosetting material in the form of a ferrule or as a latching element for later connection to the cosmetic pencil or the like can be inserted into the injection molding machine so that a composite molding is produced during the injection molding procedure, that is to say while the plastic material of the holding portion is being injected therearound. In that case freedom from germs is thus also guaranteed as under some circumstances micro-organisms or bacteria which are introduced into the injection molding machine with the insert portion are already killed off during the operation of injecting the plastic material of the holding portion therearound. Particularly preferably therefore the holding portion is produced at least partly from plastic material in the same injection molding machine in an injection molding operation which precedes the operation of injecting the applicator portion thereto, so that contact with germs is already avoided as far as possible during the production procedure.
It is advantageous if the operation of injecting the applicator portion in place is effected in such a way that a connecting layer is produced between the applicator portion and the holding portion, the connecting layer having a mixture layer comprising the applicator portion plastic material and the holding portion plastic material. That produces a secure connection, by locking intermingling of the materials involved, as between the holding portion and the applicator portion, and at the same time avoiding recesses between the holding portion and the applicator, in which micro-organisms preferably accumulate, as the materials blend fluidly and progressively into each other. The mixing effect also provides that the applicator portion can no longer be detached from the holding portion without destroying it. The mixing effect occurs in a transitional region from the holding portion to the applicator portion where the surface of the holding portion starts to melt by virtue of the hot applicator material being injected thereonto. The mixture layer is produced by mixing of the applicator portion plastic material and the holding portion plastic material with each other when the applicator portion is injected into the holding portion.
That effect is enhanced in dependence on the material involved by the operation of injecting the applicator portion on to the holding portion being effected after the injection operation for production of the holding portion, prior to the complete cooling thereof down to ambient or room temperature. A favorable processing temperature for the material of the holding portion is between 30° C. and 80° C. and preferably between 60° C. and 80° C. That corresponds to a preferred cooling time after injection of the holding portion in dependence on the material thickness of the holding portion and the ambient temperature of between 10 and 25 seconds. When using other materials however the operation of injecting the applicator portion on to the holding portion can also take place at a lower processing temperature (5° C. or less). At any event the choice of the processing temperature which is suitable in dependence on the material involved provides that the holding portion can be melted selectively to a greater or lesser degree in the operation of injecting the applicator portion thereonto, and thus the thickness of the mixture layer can be adjusted. An advantageous thickness for the mixture layer is between 1/100 mm to some 1/10 mm. Optionally the holding portion can also be preheated prior to the operation of injecting the applicator portion thereonto. In that way the operation of forming a mixture layer can also be controlled independently of the production of the holding portion and basically can also be applied to insert portions of thermoplastic material or the like.
Alternatively or in addition to the mixture layer which involves intermingling of the materials involved, the connecting layer has a positively locking connection between the applicator portion and the holding portion.
In the process for the production of an applicator according to the invention preferably an injection molding mold with a laser-sintered negative of the surface profile of the applicator portion is used in the operation of injecting the plastic material of the applicator portion on to the holding portion. That makes it possible in a simple reproducible fashion to produce the desired regularity for the surface structure with the desired profile depth of the structure elements, as is not the case with the known processes. Thus, depending on the elasticity of the applicator portion or the hardness of the plastic material of the applicator portion, it is possible to achieve on the one hand any sensation (for example velvety, rough, smooth, rubber-like and so forth) and on the other hand, depending on the respective properties of the cosmetic preparation (viscosity, surface tension, wetting or surface adhesion, etc), a desired depository and/or entrainment effect, a required capillary effect and/or a (pressure-dependent) delivery characteristic.
In an advantageous embodiment the plastic material of the applicator portion is a thermoplastic elastomer (TPE). That on the one hand can involve a block copolymer which comprises blocks of different monomers. By virtue of the possible variations in terms of chemical composition and ‘architecture’ of the molecular chains, it is possible in that way to produce plastic materials enjoying different properties. By virtue of the insolubility of the individual sequences of the chains, agglomerates or physical networks of the individual constituents are formed in the plastic material. That category includes for example styrene block copolymers, thermoplastic polyester elastomers, thermoplastic polyurethanes, soft polyolefin thermoplastic materials or thermoplastic polyamide. On the other hand it is also possible to use a TPE blend comprising a thermoplastic matrix and elastic particles. By melting the matrix it is possible to process the material like a thermoplastic material, the elastic particles imparting to the plastic material its elastic suitability for use. What is important in that respect is good thorough mixing and adhesion of the matrix to the particles. That kind of material includes PP-EPDM, PP-NR, PP-IIR blends or polyolefin thermoplastic materials in the form of a PP-EPM blend.
Using a suitable TPE material makes it possible to achieve a wide band width in terms of mechanical, touch, optical, dynamic or wetting properties, such as for example a wide range in respect of hardness, resistance to temperature, resistance to deformation, oil resistance, hydrolysis resistance, weathering resistance, workability, adhesion to the plastic materials of the holding portion, colorability, damping or cushioning, strength, abrasion wear and the like.
Particularly in regard to touch properties, it is found to be advantageous to use a thermoplastic elastomer of a hardness of between 2 and 45 Shore A. In the range of between 10 and 40 Shore A and in particular up to 15 Shore A, a thermoplastic silicone elastomer has proven to be a preferred plastic material for the applicator portion. The use of thermoplastic elastomer as a blend with silicone rubber component makes it possible to achieve an excellent separation effect between the plastic material of the applicator portion and the cosmetic preparation and thus to adjust the parameter of the (required) wetting.
Further objects, features and advantages of the invention are described in greater detail hereinafter by means of an embodiment by way of example with reference to the drawings in which:
a-1c show an embodiment of a dip applicator according to the invention,
a and 2b show a diagrammatic 3D view and a view on an enlarged scale of a part of the applicator portion of a first embodiment of the dip applicator according to the invention with a blade-like surface structure and four longitudinal passages,
a and 3b show a diagrammatic 3D view and a view on an enlarged scale of a part of the applicator portion of a second embodiment of the dip applicator according to the invention with a knob-like surface structure and six longitudinal passages,
a and 4b show a diagrammatic 3D view and a view on an enlarged scale of a part of the applicator portion of a third embodiment of the dip applicator according to the invention with a blade-like surface structure and three longitudinal passages,
The view in
b and 1c show sectional views of an applicator portion 120 which is arranged on a holding part 118 of the holding portion 116 in axial prolongation therewith and which is of a cylindrical configuration with a bevel 114. The holding part projects in the form of an attachment 122 into the applicator portion 120. That structural shape is achieved by means of a 2C injection molding process by injecting around the holding part 118 and the projection 122 of the holding portion 116 which was injection molded in a first mold, in a second injection molding mold. If the holding portion 116 is preferably produced from thermoplastic material such as polyethylene, polypropylene, polyvinyl chloride, polyacetate, polyacetal, polystyrene or mixed polymers thereof, or polyamide, and if the applicator portion 120 of thermoplastic elastomer, silicone rubber, NBR, soft PVC or the like is injected on to the holding portion 116 immediately after injection thereof, a mixture layer is formed, in which the various kinds of plastic materials of the holding portion 116 and the applicator portion 120 mix with each other (for example by diffusion). If such an applicator is cut open, that mixture layer can be recognised with the naked eye or under a microscope and analysed. The mixture layer will turn out to be of greater or lesser thickness depending on the respective temperature of the holding portion in the operation of injecting the applicator portion.
The applicator portion can be for example solid as shown in
In addition to the connection between the holding portion 116 and the applicator portion 120 by the mixture layer, the applicator 100, in the region of the holding part 118, that is to say at the transition from the holding portion 116 to the applicator portion 120, also has elements 126 of a positively locking connection, more specifically a peripherally extending annular groove in the outer periphery of the holding portion 116 and a corresponding, peripherally extending annular projection at the inner periphery of the applicator portion 120. As shown, those elements 126 can be provided in addition to the connection afforded by the mixing effect of the mixture layer in order to increase the strength of the connection between the holding portion 116 and the applicator portion 120 without worsening the hygiene properties, but they are not absolutely necessary.
Assembly of the dip applicator 100 and the container takes place in a final assembly process after the container has been filled with cosmetic preparation. In that situation the holding portion 116 together with the applicator portion 120 is dipped into the container, the filling height of which generally reaches into the region of the dipped applicator portion 120. The dip applicator is then screwed to the container and thus tightly closed.
a shows the applicator portion 200 of the applicator according to the invention in accordance with a first embodiment, the surface of which has a plurality of structure elements in the form of blades 210. The applicator portion is basically rotationally symmetrical about its longitudinal axis which is horizontal in the illustrated view and which coincides with the direction of lengthwise extent of the applicator (not shown). The applicator portion narrows only slightly in the direction of its lengthwise extent with increasing distance from the holding portion and is closed off by a dome 212 in the form of a segment of a sphere. The blades 210 extend in an annular configuration in mutually parallel relationship and around the applicator portion perpendicularly to the direction of the lengthwise extent thereof and are disposed in perpendicular relationship to the base surface thereof. As is shown on an enlarged scale in
In the illustrated manner the applicator portion is injected with its flat (right-hand) end 214 on to the holding portion (not shown) in the fashion shown in
a and 3b also show an elongate applicator portion 300 which is basically rotationally symmetrical and which is of the same basic contour as that shown in
The embodiment of the applicator portion 400, which is shown in
Finally the sectional view in
The embodiment shown by way of example in
The embodiment shown in
In the embodiment shown in
The applicator portions 1300 in
In the example of
What is common to all the illustrated embodiments of applicator portions is that, in comparison with for example flock-coated applicators, they involve only a slight increase in surface area, that is to say a structure surface which is smaller in relation to the base surface of the applicator portion, whereby the risk of microbial pollution is reduced even after the first use. In addition the configuration according to the invention of one or more passages on the outside surface of the applicator portion provides for an adequate supply of cosmetic preparation in particular to the applicator tip which is mostly preferably used for application of the preparation, if the passage or passages extend substantially over the entire length of the applicator portion and the passage is adapted to the properties of the preparation by virtue of a suitable choice of the plastic material of the applicator portion and the dimensions involved.
The entrainment capability (the holding volume and the holding force) can also be adjusted in a very much more specifically targeted fashion by virtue of the choice of suitable structure elements and thus individually matched to each situation of use, that is to say to the part of the skin which is intended for the preparation to be applied thereto, and the properties of the cosmetic preparation (viscosity, surface adhesion, coverage). That is facilitated by the injection molding process according to the invention which is characterised by use of an injection molding mold with a laser-sintered negative of the surface profile of the applicator portion.
The entrainment capability can also be adjusted to the respective situation of use by virtue of a suitable choice in respect of the frictional resistance, for example by making a suitable choice of the plastic material for the applicator portion and the hardness thereof.
Neither the enumeration of the examples of use of the applicator according to the invention nor the structures thereof are to be interpreted as definitive.
For some situations of use, besides the structures described in detail hereinbefore, advantages are to be found for example in crown-shaped structures which each include peripherally arranged prongs. The crowns can be hexagonal with a respective prong of the same or different heights, at each respective corner. The prongs of the crowns can be for example of a height of between about 0.2 mm and 0.4 mm above the base surface of the applicator portion while the surface of each of the crowns is recessed at the center thereof in a cup-shaped configuration.
Basically each surface structure can have one or more preferred directions which do not necessarily have to be perpendicular to the surface of the applicator portion. The preferred direction of the structure elements can also be set in dependence on the ergonomic handling of the applicator depending on the respectively intended use.
The structures and passages set forth by way of example can also be used in combination on the same applicator portion. For example different structures for different uses (blending, distribution and so forth) can be provided on opposite surfaces of the same applicator portion. It is also possible for the structure elements to be mixed on an application surface or over the entire applicator portion.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP05/10964 | 10/12/2005 | WO | 00 | 12/13/2006 |