EP1992251B9 - Small cosmetic brush with many bristles for applying make-up - Google Patents

Abstract

The brush (1) has a bristle portion (2) with a central base body (5) and a set of bristles (6) that stick out from the base body and serve for an application of a cosmetic product. The bristles are provided with a high bristle density of 6 bristles per square millimeter and consist of a plastic material that has a shore hardness of more than 40. The bristles are provided next to each other on a circumferential area (7) of the base body with a base distance of 0.63 millimeter (mm) with respect to each other.

Description

The invention relates to a cosmetic brush, in particular a mascara brush or a brush for hair dyeing, comprising a bristle portion with a base body and a plurality of bristles which protrude from the base body and by means of which a cosmetic can be applied.

Such a cosmetic brush and an associated Spritzgussherstellungsverfahren are for example in the DE 25 59 273 A1 described. The hollow base body and the bristles are formed integrally there is a thermoplastic, elastically deformable plastic, such as an elastically compliant polyethylene used. As a result, the bristles are soft and elastic, making the application of the cosmetic feels very pleasant. Plastics with a Shore A hardness determined in accordance with DIN EN ISO 868 in the range between 60 and 95 are currently usually used in such injection molding production processes. Furthermore, the density determined according to DIN EN ISO 1183 of relatively soft polyolefins commonly used in this field of application is typically in the range between 0.91 g / cm ³ and 0.94 g / cm ³ . However, the use of such soft elastic plastics also brings some limitations in terms of economically feasible embodiments of the cosmetic brush with it. In addition, these relatively soft and elastic materials, such as polyethylene and polypropylene, often are not sufficiently chemically compatible with the cosmetic to be applied.

In addition to the conventional mascara brushes, in which a plurality of bristles between a hairpin-shaped bent wire section are determined by twisting thereof, brushes of the type described above are increasingly being realized by means of injection molding and placed on the market. In these brushes, the bristles are also injection-molded elements, i. H. they are not bristles in the original sense. For the sake of simplicity, however, this terminology will be retained below.

In the EP 0 761 125 A1 is a mascara applicator described in the form of a flat brush with tufts of hair, which are inserted into a flat handle, glued, pinned or pressed. The hairs have a maximum distance of 2 to 3 mm, their diameter is between 0.04 and 0.7 mm and their length is greater than 5 mm. Their hardness is between 10 Shore A and 60 Shore D. They consist for example of synthetic material, such as vulcanized elastomer or a thermoplastic.

The object of the invention is to provide a cosmetic brush of the type described, which can be economically finished, has good transfer properties for the applied cosmetic and lashes or hair well separates and combs during the application and combing.

To solve this problem, a cosmetic brush according to the features of claim 1 is given. In the case of the cosmetic brush according to the invention, the bristles have a high bristle density of at least 6 bristles per square millimeter and consist of a plastic material which has a Shore hardness D of more than 40. The cosmetic brush is a one-piece plastic injection molded part.

The cosmetic brush according to the invention advantageously has a very high bristle density. In contrast to the hitherto commercially available injection-molded mascara brushes, which have a maximum of about 500 to 600 bristles, a cosmetic brush according to the invention, in contrast, a significantly higher bristle number of, for example, at least 800 bristles and preferably even at least 1000 have. Even higher bristle numbers of 1500 and more are possible.

A high bristle density is particularly advantageous when an application to very fine hair or eyelashes should be made. But otherwise causes the high bristle density of the cosmetic brush according to the invention very good combing and separation properties for the hair or eyelashes. This is especially true for relatively short and / or downwardly projecting eyelashes. Such unusual and unsatisfactory to handle with conventional cosmetic brushes conditions occur especially in Asian and older women. With the cosmetic brush according to the invention, however, very good results are achieved even under such difficult conditions. In addition, a very uniform distribution of the cosmetic to be applied can be achieved with a high bristle density. As the number of bristles increases, more support elements are available for the transfer of the cosmetic from a reservoir to the point of application. Finally, the bristles, which are very close to one another when the bristle density is high, also promote the so-called curl effect, in which the eyelashes are bent upward by rotating the cosmetic brush. This advantage is appreciated above all by Asian consumers, with the cosmetic brushes used in this region in particular having relatively small diameters due to the widespread Schlaffflider there.

It was further recognized that the advantageous high bristle densities can be made very difficult with the previously used soft plastic materials. In order to achieve the described application target, especially for the stated target groups of older ladies and Asian women, cosmetic brushes with a high bristle density are required. This high bristle density can be achieved with relatively small bristles in particular only with very small bristle dimensions, the but can not be realized with the plastics used so far. For this purpose, the plastics used in the prior art are too soft.

In contrast, the invention makes use of a considerably harder plastic material than in the prior art. The Shore D hardness of the plastic material used in the cosmetic brush according to the invention, which is determined in particular according to DIN EN ISO 868, is well above the Shore hardness values of the plastics hitherto used for the injection molding of cosmetic brushes. The harder plastic provided according to the invention makes it possible in the first place to economically produce high bristle densities. In particular, it also provides the rigidity and flexibility needed for the relatively small bristles. The plastic materials used preferably contain no plasticizer.

At the same time it has been shown that the use of the harder plastic material - contrary to the actual expectations - practically does not affect the application comfort of the brush according to the invention. The application is designed to be just as comfortable as a conventional brush, whose bristles are made of a softer plastic. This is also due to the small bristle cross-sectional geometry, which is associated in particular with the high bristle density and causes a pleasantly soft impression despite the hard plastic material.

Advantageous embodiments of the cosmetic brush according to the invention emerge from the features of the claims dependent on claim 1.

Favorable is a variant in which the plastic material has a Shore hardness D of at least 45 and in particular of at most 60. Thus, particularly high bristle densities can be realized. Brushes with a number of bristles of, for example, more than 2,000 can then be produced without difficulty - in particular also by injection molding.

Furthermore, the bristle density can be at most 50 bristles per square millimeter. With bristle densities up to this preferred upper limit, on the one hand, all applications are recorded, even those in which the cosmetic is applied to very fine structures. On the other hand, these bristle densities can still be produced very well.

According to another favorable variant, the bristle portion has a stocking length of 18 mm to 30 mm extending in the direction of a central axis, within which bristles are arranged. This covers all typically occurring longitudinal extensions of the application area.

Preferably, adjacent bristles on a surface of the base body also have a base distance of at most 0.63 mm to each other. This close spacing favors the combing and separation properties as well as the curl effect.

With a further advantageous embodiment, in which the bristles on a surface of the base body have a base diameter of at most 0.3 mm, in particular of 0.18 mm, a particularly high packing density of the bristles can be achieved.

Also favorable is a variant in which the bristles protrude with a bristle length of at most 2.5 mm from a surface of the base body.

Another preferred embodiment is one in which the main body has a diameter of up to 5 mm. This and a maximum bristle length of up to 2.5 mm results in a maximum outside diameter of up to 10 mm. In particular, outer diameters of 4.5 mm corresponding to the current standard value for mascara brushes and outer diameters of, for example, 6 to 7 mm are possible. With a larger body there is more space for bristles. Thus, cosmetic brushes with a particularly high number of bristles can be realized more easily. The bristle length and the diameter of the main body are particularly matched to provide a well-proportioned and appealing visual impression and to fulfill the desired function satisfactorily.

The main body of the brush may have different cross-sectional geometries, preferably a round. But also a not round cross section is possible.

According to a further advantageous embodiment, the base body runs conically in the direction of a center axis. The cross-sectional area therefore decreases in particular as the distance from a front tip of the cosmetic brush decreases. As a result, a preferably continuously increasing bristle density results towards the tip, but a high bristle density is already present in the abovementioned region at the end of the bristle section facing the stem approaching, ie, at the opposite end.

Another preferred variant is characterized in that the main body has a varying in the direction of a central axis cross-sectional profile. Along the center axis, the cross-section of the basic body can thus be e.g. enlarge or reduce in sections. This results in subregions with smaller or larger high bristle density. In particular, therefore, the bristle density in the longitudinal direction can vary or fluctuate in a certain way.

Furthermore, it is advantageously provided that the bristles each have an outwardly tapered conical shape with a cone angle of 1 ° to 5 °, in particular of about 4 °. In these conical bristles, the particular round bristle cross-sectional area decreases with increasing distance from a surface of the main body. A certain conicity of the bristles facilitates the ejection of the finished cast brush from the mold used for injection molding. On the other hand, the taper should not be too large to allow a high bristle density. The conical bristle shape is especially well suited for the small bristle geometries due to the high bristle densities. The favorable conical shape means that the bristles despite their small cross-sectional areas and the hard plastic materials used have a very high breaking strength and a very high erecting capacity.

According to another favorable embodiment, the bristles have at their respective outer end a rounded bristle tip having a tip radius of curvature of at most 0.05 mm. This rounding prevents hooking the bristles on eyelashes or hair and allows at the same time an exact separation of eyelashes or hair, even if they are arranged one above the other and not next to each other.

In addition, the bristle surface may in particular be smooth or have a structure.

Likewise, it is preferably possible that the bristles are arranged like a wreath around a longitudinal axis of the cosmetic brush, wherein per wreath up to about 50 bristles may be provided.

Fig. 1

ein Ausführungsbeispiel eines Kosmetikbürstchens mit einer hohen Borstendichte in einem Längsschnitt,

Fig. 2

das Kosmetikbürstchen gemäß Fig. 1 in einer Darstellung des Schnitts längs der Linie II-II in Fig.1,

Fig. 3

eine Borste des Kosmetikbürstchens gemäß Fig. 1, und

Fig. 4 und 5

jeweils einen Ausschnitt einer abgewickelten Umfangsfläche eines Ausführungsbeispiels eines Kosmetikbürstchens mit jeweils unterschiedlicher, hoher Borstendichte.

Further features, advantages and details of the invention will become apparent from the following description of exemplary embodiments with reference to the drawing. It shows:

Fig. 1

an embodiment of a cosmetic brush with a high bristle density in a longitudinal section,

Fig. 2

the cosmetic brush according to Fig. 1 in a representation of the section along the line II-II in Fig.1 .

Fig. 3

a bristle of the cosmetic brush according to Fig. 1 , and

4 and 5

in each case a section of a developed peripheral surface of an embodiment of a cosmetic brush, each having a different, high bristle density.

Corresponding parts are in the Fig. 1 to 5 provided with the same reference numerals.

In Fig. 1 and 2 an embodiment of a cosmetic brush 1 in the form of a mascara brush is shown. It is designed as a one-piece plastic injection molded part with a round cross-sectional geometry. The sprayed cosmetic brush 1 has as a main component a bristle portion 2 and an axially formed thereon stem extension 3, both of which extend in the direction of a central axis 4. The bristle section 2 comprises a central main body 5, which serves as a carrier for a plurality of bristles 6 projecting radially outward from the main body 5. The bristles 6 are each integrally formed on a peripheral surface 7 of the main body 5. Basically, the base body in alternative embodiments, not shown, also have a non-circular cross section and / or a conical or otherwise varying longitudinal direction in the direction of the center axis 4.

All subcomponents of the cosmetic brush 1, that is to say the stem attachment 3, the base body 5 and the bristles 6, consist of a uniform comparatively hard plastic material and are produced by means of a single-stage injection molding process. As a plastic material in the illustrated embodiment, a plasticizer-free polyamide having a Shore D hardness of about 54 and a specific example according to DIN EN ISO 1183 specific density of about 1.02 g / cm ^{3 is} provided. In principle, however, other preferably likewise plasticizer-free plastics having a high Shore hardness D of in particular more than 40 and preferably more than 45 are suitable. As an alternative material, for example, a correspondingly hard polyester or polyacrylic would be suitable. In this regard, particularly suitable plastic materials have a density according to DIN EN ISO 1183 in the range between 0.95 g / cm ³ and 1.30 g / cm ³ , preferably between 0.98 g / cm ³ and 1.04 g / cm ³ , These preferred plastic materials Moreover, they are chemically completely compatible with the cosmetic to be applied by means of the cosmetic brush 1.

Due to the hard plastic material used, the cosmetic brush 1 can be produced with a very high bristle density and accordingly also with a very high number of bristles.

How out Fig. 2 it can be seen, the bristles 6 are arranged in the embodiment in bristle rings to 16 circumferentially uniformly distributed bristles 6. Adjacent bristles 6 of a bristle ring are each offset by a bristle offset angle α of 22.5 ° in the circumferential direction against each other. The bristle portion 2 has a standard stocking length L _BS of about 25 mm, within which a total of 78 bristle rings are arranged in the embodiment. This results in the in Fig. 1 and 2 Cosmetic brush 1 shown a bristle number of 1248 and an average bristle density of about 8.1 bristles / mm ² , wherein as a reference surface, the peripheral surface 7 of the base body 5 is used.

In the exemplary embodiment, the following further geometry parameters are provided:

The base body 5 has a base diameter D _GR of 2 mm and the bristle portion has a determined by the base body 5 and the molded bristles 6 outer diameter D _AU of 4.5 mm. Accordingly, the bristles 6 have a bristle length L _BO of 1.25 mm.

As from the in Fig. 3 shown enlarged representation of a single of the bristles 6, the bristles 6 have a conical shape, the after outside with a cone angle β of 4 ° tapers. Accordingly, the round cross-sectional area at the base, ie at the juncture to the main body 5 is greater than at the outer earth region of the bristle 6. The bristles 6 have a base diameter D _BA of 0.166 mm and open at its outer free end into a rounded tip, the has a tip radius of curvature R of 0.038 mm. In the direction of the center axis 4 adjacent bristles 6 are spaced at their respective base by a base distance A _BA of 0.63 mm from each other.

From the in 4 and 5 shown sections of unwound outer peripheral surfaces of cosmetic brushes, each with different bristle density shows that the bristles 6 are arranged in parallel longitudinal rows, within the longitudinal rows adjacent bristles 6 each have a uniform, determined by a Reihenrastermaß distance to each other and adjacent longitudinal rows each by half row raster are offset from each other in the longitudinal direction of the longitudinal rows. This is especially true both for viewing in the direction of the center axis 4 and for viewing in the direction perpendicular to the center axis direction circumferential direction. By this staggered arrangement of the bristles 6, a high bristle density can be achieved.

In Fig. 4 For example, a 1 mm x 1 mm section of a developed peripheral surface 7 of a cosmetic brush 8 having a bristle density of 7 bristles / mm ^{2 is} shown. If one sets the same dimensions of the main body 5 as in the cosmetic brush 1 according to Fig. 1, and 2 This results in a bristle number of slightly more than 1000, namely 1078.

In Fig. 5 a 1 mm x mm section of a developed peripheral surface 7 of a cosmetic brush 9 with a bristle density of 42 bristles / mm ^{2 is} shown. In the case of the bristle diameter selected in this embodiment, this is the highest achievable bristle density. Higher values can be achieved by reducing the bristle diameter.

Claims (14)

1. Cosmetics brush, in particular a mascara brush or a brush for dyeing hair, comprising a bristle portion (2) with a basic body (5) and a plurality of bristles (6) that protrude from the basic body (5) and by means of which a cosmetic can be applied, wherein the bristles (6) have a high bristle density of at least 6 bristles (6) per square millimetre and consist of a plastic material having a Shore hardness D of more than 40, and the cosmetics brush (1) is a single-piece plastic injection-moulded part.
2. Cosmetics brush according to claim 1, characterised in that the plastic material has a Shore hardness D of at least 45, and in particular of at most 60.
3. Cosmetics brush according to claim 1, characterised in that the bristle density is at most 50 bristles (6) per square millimetre.
4. Cosmetics brush according to claim 1, characterised in that the bristle portion (2) has a covered length (L_BS) of 18 mm to 30 mm extending in the direction of a central axis (4), within which the bristles (6) are disposed.
5. Cosmetics brush according to claim 1, characterised in that the neighbouring bristles (6) on a surface (7) of the basic body (5) have a base distance (A_BA) of at most 0.63 mm.
6. Cosmetics brush according to claim 1, characterised in that the bristles (6) on a surface (7) of the basic body (5) have a base diameter (D_BA) of at most 0.3 mm, in particular of 0.166 mm.
7. Cosmetics brush according to claim 1, characterised in that the bristles (6) protrude from a surface (7) of the basic body (5) with a bristle length (L_BO) of at most 2.5 mm.
8. Cosmetics brush according to claim 1, characterised in that the basic body (5) has a diameter (D_GR) of up to 5 mm.
9. Cosmetics brush according to claim 1, characterised in that the bristles (6) each have an outwardly tapering conical shape with a cone angle (β) of 1° to 5°, in particular of about 4°.
10. Cosmetics brush according to claim 1, characterised in that the bristles (6) have at their respective outer end a rounded bristle tip with a curvature radius (R) of the tip of at most 0.05 mm.
11. Cosmetics brush according to claim 1, characterised in that the basic body (5) has a non-circular cross section.
12. Cosmetics brush according to claim 1, characterised in that the basic body (5) extends in a conical manner in the direction of a central axis (4).
13. Cosmetics brush according to claim 1, characterised in that the basic body (5) has a cross-sectional profile varying in the direction of a central axis (4).
14. Cosmetics brush according to claim 1, characterised in that the plastic material has a density in the range of between 0.95 g/cm³ and 1.30 g/cm³, preferably between 0.98 g/cm³ and 1.04 g/cm³.

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