EP0310471A1 - Method for compacting a powder-based cosmetic preparation - Google Patents

Abstract

A quantity of the pulverulent preparation (2), advantageously containing a binder, is placed in an enclosure (1) which is open at its upper part and whose lower part is delimited by a cup (4) intended to contain, at the end of 'operation, the resulting compact. The preparation (2) is hot pressed, the compacting piston (13) being equipped with a heating device (14). Heating provides better cohesion of the compact and, if a binder is present, its fluidity is increased. The invention offers the possibility of using microencapsulated binders as well as hydrophobic binders. Usable for compact make-up powders.

Description

The present invention relates to the field of cosmetic preparations constituted by compressed dry powders or by mixtures of compressed dry powders, or also by powder-anhydrous binder mixtures, these cosmetic preparations, which advantageously contain colored or dyed pigments, used in particular for face makeup, and often being designated by the term "compact".

Generally, it is known that this type of powder consists of a powder base chosen in particular from talc, rice starch, kaolin, silk powder or polymer powder to which pigments are added to obtain coloring, for example titanium, zinc or iron oxides. When a pearlescent effect is desired, a mica powder or a mica powder coated with metal oxides, in particular titanium and bismuth, or aluminum powders is added. To obtain sufficient adhesion to the skin, a small amount of binder is generally added, for example vegetable, animal, mineral or synthetic oils, zinc stearate, sorbitol or lanolin. These powders can also contain preservatives such as methylparaben or propylparaben, surfactants, preferably nonionic and perfumes.

To obtain a make-up compact, the basic fluid powder is placed in the bottom of an enclosure, in which a piston or a punch is slid which compresses said powder to ensure the cohesion of its grains. In general, it is arranged so that the enclosure is, at its base, delimited by a cup which receives the resulting compact product.

By this compacting operation, it is sought to obtain the strongest possible cohesion of the grains of the base powder, in order to avoid crumbling of the compact; this result, which depends on the texture of the powder subjected to compaction, is not always easy to obtain. Furthermore, binders can be used, in combination with the powder, to modify the texture of the compact or improve this cohesion; in this case, the binders must be distributed regularly and homogeneously within the product during compaction, which, in practice, is not always carried out.

The present invention provides a solution to the above problems.

According to the invention, the compaction is carried out, no longer at room temperature, but hot. Under these conditions, the grains of the base powder adhere more strongly to each other, to give the desired effect. The binders, if they are present, then see their fluidity increase, from which it results that they disperse more easily and faster within the product during compaction. It is therefore possible, by operating hot, to introduce less binder than working at room temperature, for the same cohesion of the final compact; the texture of said compact will then be more "powdery", thus facilitating the distribution of the product. Furthermore, if a quantity of binder equal to that which would be used when working at room temperature is introduced into a hot operation, a more "creamy" texture of the compact is obtained. The invention therefore makes it possible to choose a texture of compact within a wider range, by adjusting the quantity of binder used.

The invention also offers other additional advantages: it allows, in fact, the use of microencapsulated binders, providing ease of handling of the compositions to be compacted, the pressure applied during compacting causing these microcapsules to burst; it also allows the use of hydrophobic binders, such as waxes, which could not be used if there was no heat input, the compacts more hydrophobic obtained leading to better water-resistant makeup.

It has also been found that a compact, obtained in its cup in the conventional manner indicated above, is not homogeneous over its height, in particular that it is more brittle in the region near the bottom of the cup, and harder in the opposite region, on the surface of which the compacting piston was applied. The reason is that the pressure applied to the fluid powder is not transmitted perfectly through the powder layer, due to the elasticity of the latter. However, in use, it is easier to take the powder from a more brittle part.

The present invention proposes, in order to be able to benefit from this advantage, a technique which makes it possible to directly obtain a compact product packaging, in which the user has access to the product through this more brittle part. To this end, provision is made for the cup placed in the bottom of the enclosure to have at least one opening, said enclosure being delimited, at this (or these) opening (s), by a base counterplate. Under these conditions, after the compacting operation, in the final packaging consisting for example of a box, the resulting cup is presented turned over on itself so that the product can be withdrawn through its opening (s) ), on the side which has not been directly affected by the compacting piston and which is therefore less hard.

Furthermore, it has been found, in the implementation of compacting in a conventional manner, that the edges of the compacts often have defects, the compacting being always more homogeneous in the central part of the compact. With the technique which has just been indicated, it suffices to have the opening (s) at the bottom of the cup, mainly in the central region thereof. In this way, the edges of the compact are hidden in the final packaging, which then offers a more aesthetic appearance.

According to variants of this technique, it is possible to ensure that the counterplate is slightly concave in line with the opening of the cup so that the compact protrudes from the bottom of the cup, through said opening, in a slightly domed part. also giving a more aesthetic appearance to the whole.

Another advantage of this technique is that the aforementioned openings can have any cutout, therefore, advantageously, original or aesthetic cutouts, but that, in all cases, the same compacting piston can be used for a shaped cup given overall. It suffices simply to replace, each time, in the compaction system, the cup with another comprising another type of opening.

It is possible, in the compacting system, to interpose between the base counterplate and the cup a flexible protective film, heat resistant which may be applied and advantageously constituting a film of inviolability of the powder. The protective film can thus be replaced by a rigid cover mounted in place of the flexible film, this cover can be obtained by injection and can be secured to the bottom of the cup by snap-fastening. It is also possible to install separating bars on the bottom of the cup, in the compacting enclosure, so as to compact, in the same operation, powders of different natures, for example containing pigments of different colors or shades, in particular to present, in the same packaging, complementary makeup products.

The present invention therefore firstly relates to a process for the compacting of a cosmetic preparation based on powder, according to which a quantity of said pulverulent preparation is placed in an enclosure which is open at its upper part and whose lower part is delimited by a cup intended to contain, at the end of the operation, the resulting compact cosmetic preparation, and compression of the preparation is carried out using a compaction gun moving in said enclosure substantially perpendicular to the mean plane of the layer of said pulverulent preparation, characterized in that the hot compaction is carried out.

Preferably, a compacting piston equipped with a heating device is used. Furthermore, the temperature of the compacting piston is adjusted to a temperature of, for example, between 40 and 300 ° C. One can also preheat to 1ØØ ° C, on the one hand, the cups, and on the other hand, the powder in a heating hopper before hot compaction.

Advantageously, a powdery cosmetic preparation is used which contains at least one binder, in particular at a rate of 2 to 15% by weight relative to the totality of the powdery cosmetic preparation. Among the binders which can be used, mention may in particular be made of petrolatum oil and castor oil. The binders can advantageously be packaged in microcapsules. In this case, during compaction, the compression applied to the pulverulent composition ensures the bursting of the microcapsules, which are perfectly mixed with the base powder and whose content constituted by the binder itself spreads uniformly and rapidly within the base powder, to ensure good cohesion of its grains.

According to the invention, for a given cosmetic preparation, it is possible to choose a binder content lower or equal to that which would be chosen for compacting without adding heat, in order to obtain a respectively more powdery or more creamy texture of the cosmetic preparation. compact.

Also, according to the invention, it is possible to use binders of hydrophobic nature, such as waxes; one can thus obtain a make-up whose hydrophobic character is reinforced, that is to say having better water resistance.

According to an advantageous characteristic of the present invention, in which the cup is intended to constitute, with the compact cosmetic preparation, a packaging element for the latter, a cup is used whose bottom has at least one opening, said enclosure being delimited , in the region of said (or said) opening (s) by a base counterplate on which said cup rests, the surface of the compact cosmetic preparation, which is accessible by said (or said) opening (s), constituting , in the final packaging of the compact cosmetic preparation, the surface area for sampling, by the user, of said preparation.

In particular, it is possible to use a cup whose opening (s) is (or are) made in the central part of the base, the border region of the compact cosmetic preparation being protected from the outside, in the final packaging, by the peripheral zone of the bottom of said cup.

According to a variant, a base counter plate can be used, the surface of which facing the (or each) opening of the bottom of the cup is slightly concave, to give the compact in this area a slightly convex projecting surface relative to the plane of the outer wall of the bottom of the cup.

Furthermore, one can have, between the bottom of the perforated cup and the base plate, a flexible protective film capable of remaining integral with said cup and its contents after compaction. This film, apart from the fact that it must, in hot compaction, have good heat resistance, must be made of an extremely flexible material in the case where the previous variant is used.

In particular, a film can be used welded to the outer edge of the bottom of the cup or a completely adhesive film on its surface facing said bottom, said film in this case achieving the inviolability of the compact cosmetic preparation in its associated cup. In the case where the film is completely adhesive, one obtains, when the latter is removed, a surface of the compact product which comprises a slight screening, which can be sought from an aesthetic point of view.

Also, one can have, in the internal space of the enclosure, at least one separating bar of powdered cosmetic preparations of different natures, so as to make it rest on the counterplate by crossing the opening (or at least one of the openings) at the bottom of the cup, and simultaneously compact these preparations.

Finally, a layer of liquid glue, for example hot-melt, can be deposited on the bottom of a case capable of receiving by interlocking the cup containing the associated compact preparation, the bottom of said cup being turned outwards, and allowing it to harden. the adhesive to secure the cup to the bottom of the housing and to the lower internal edge of the side wall of said housing, to constitute the final packaging of the compact preparation.

The present invention also relates to compact cosmetic preparations obtained by the process defined above.

To better understand the object of the present invention, there will be described below, by way of purely indicative and nonlimiting examples, several embodiments shown in the accompanying drawing.

• - la figure 1 représente une vue schématique en coupe verticale d'un dispositif de compactage adapté pour la mise en oeuvre du procédé conforme à la présente invention ;
• - la figure 2 est une vue en perspective de la coupelle renfermant la préparation cosmétique compacte, telle qu'elle est obtenue en fin de compactage par le dispo­sitif de la figure 1, cette coupelle étant présentée en position retournée afin de montrer le côté de prélèvement du produit compact :
• - la figure 3 représente, en coupe longitudinale, la coupelle de la figure 1 après mise en place dans un boîtier de présentation ;
• - la figure 4 est une vue analogue à la figure 1 d'un dispositif de compactage réalisé selon une variante ;
• - la figure 5 est une vue analogue à la figure 1, illustrant la possibilité de réaliser des coupelles à plusieurs compartiments : et
• - la figure 6 répresente la vue de dessus de la coupelle de la figure 5, après compactage, montrant les sur­faces de prélèvement des produits compactés dans ces compar­timents.

On this drawing :

• - Figure 1 shows a schematic view in vertical section of a compacting device suitable for implementing the method according to the present invention;
• - Figure 2 is a perspective view of the cup containing the compact cosmetic preparation, as obtained at the end of compaction by the device of Figure 1, this cup being presented in the inverted position in order to show the sampling side of the compact product:
• - Figure 3 shows, in longitudinal section, the cup of Figure 1 after installation in a presentation box;
• - Figure 4 is a view similar to Figure 1 of a compacting device produced according to a variant;
• FIG. 5 is a view similar to FIG. 1, illustrating the possibility of making cups with several compartments: and
• - Figure 6 shows the top view of the cup of Figure 5, after compacting, showing the sampling surfaces of the compacted products in these compartments.

Referring to FIG. 1, it can be seen that an enclosure has been designated by 1 in which an amount of powder 2 has been placed intended to be compacted. This powder has the following weight composition:
- Talc 40%
- Pigments 10%
- Pearlizing agent (mica) 4Ø%
- Binder (petroleum jelly, jojoba oil) possibly microencapsulated 10%

The amount of binder is less than the normal amount that would be used in conventional compaction without the addition of heat.

The enclosure 1 is delimited by a horizontal support 3, serving as a counter-plate in the powder compacting operation 2, by a cup 4 resting on said counter-plate 3, and by a tubular sleeve 5.

The cup 4, made of plastic by example, is constituted by a rectangular bottom 6, to which is connected a side wall 7 of low height. The quantity of fluid powder 2 introduced and the dimensions of the cup 4 are calculated so that the compaction leads to a flat parallelepiped block 8 (FIG. 3), the upper surface of which is flush with the free edge of the side wall 7 of the cup 4. The bottom 6 of the latter has an opening 9 of ellipsoidal shape, centered on the center of the bottom 6 and occupying a large surface of said bottom.

The sleeve 5, of rectangular cross section corresponding to the internal cross section of the cup 4, has a recess 10 from its internal wall, at a distance from one of its edges which is equal to the height of the cup 4.

For compaction, the cup 4 rests on the counter plate 3 with the interposition of a film 11, the sleeve 5 coming to fit axially on the cup 4, so that the free upper edge of the latter abuts against the recess 10, the internal surfaces of the wall 7 and of the sleeve 5 being placed in the extension of one another.

The film 11 is a very flexible plastic film such as polycarbonate or polyester; its shape and dimensions correspond to those of the bottom of the cup 4; moreover, it is extended laterally by a tongue 12, as is clearly visible in FIG. 2. The film 11 is bonded by its border to the periphery of the outer wall of the bottom 6, or else it is completely adhesive on its surface. opposite the bottom 6 of the cup 4.

In the enclosure 1, a piston 13 is slidably mounted, which is equipped with a heating device 14, for example an electrical resistance, adapted to heat the wall of the piston 13 intended to compress the powder as uniformly as possible. 2.

For compaction, the piston 13 is applied, the device 14 being in service, on the powder 2, the level of which exceeds that of the upper edge of the cup 4, until the compact is obtained 8. The compaction pressure is between 4Ø and 4ØØ bars and it is maintained for 1 to 15 seconds. The temperature of the piston 13, when it comes to compress the powder 2, is of the order of 1ØØ to 3ØØ ° C. Under these conditions, the binder distributes better and faster within the particles constituting the base of the powder. One obtains a cohesion of the resulting compact 8 at least equivalent to that which would have been obtained with the use of a normal amount of binder, for a conventional compaction without heat input. In addition, the texture of the resulting compact is a more powdery texture, allowing easier distribution of the powder.

After removing the piston and removing the sleeve 5, the assembly shown in FIG. 2 is obtained, consisting of the cup 4, the compact 8 and the film 11.

This assembly is then placed, in the inverted position, as shown in FIG. 3, in a housing 15 whose solid bottom 16 is connected to a side wall 17, the internal cross section of this housing 15 being equal to or slightly greater than the cross section of the cup 4.

Before the introduction of the assembly of FIG. 2, on the bottom 16 of the housing 15, a layer of hot-melt adhesive 18 has been placed in the liquid state. Taking this adhesive allows the compact 8 to be fixed to the bottom 16 of the housing 15; moreover, the hot-melt adhesive 18, while it is still liquid, rises laterally against the wall 17, in order to ensure total attachment of the cup 4 and of the housing 15.

In use, the film 11 is removed in one piece by grasping the tongue 12 and there is then access to the compact 8 through the opening 9 of the cup. Access to the compact product is here by the less hard part of the compact 8, due to the mode of formation of the latter, which further contributes to the ease of removal of the product by the user. Furthermore, any defects in the edge of the compact 8 are hidden from view, this edge being covered by the periphery of the bottom 6.

In the packaging of FIG. 3, the bonding of the compact 8 to the bottom 16 of the housing 15, avoids inadvertent cracking of the compact 8 either in use, when the user is required to press the compact 8, or at the time of transportation.

In Figure 4, there is shown an alternative embodiment according to which the counter plate 3 a has, in its region facing the opening 9 of the bottom 6 of the cup 4, a slightly concave shape. In this way, a compact 8 is obtained which projects slightly through the opening 9, thus giving an aesthetic effect to the resulting packaging.

FIG. 5 illustrates another possibility offered by the present invention, namely that of providing, in enclosure 1, on the bottom 6 of the cup 4, a transverse separation bar 19 formed between the edges of the bottom. 6 delimiting the opening 9. This bar 19 constitutes a separation allowing the introduction, into the enclosure, of two types of pulverulent substances, 2 a , 2 b , differing for example by the color of the pigments which they contain, and constituting, for example, complementary makeup products. The bar 19 may have a curved shape also giving an aesthetic note to the final packaging of the compact 8.

It is understood that the embodiments described above are in no way limiting and may give rise to any desirable modifications, without departing from the scope of the present invention; in particular, the use of cups with a bottom is possible, this process therefore being applicable to conventional compaction or to reverse compaction defined in the French patent application filed by the applicant company on the same day as the present application.

Claims (18)

1 - Method for compacting a cosmetic powder-based preparation (2; 2 a - 2 b ), according to which a quantity of said powdery preparation (2; 2 a - 2 b ) is placed in an enclosure (1) which is open at its upper part and whose lower part is delimited by a cup (4) intended to contain, at the end of the operation, the resulting compact cosmetic preparation (8; 8 a - 8 b ), and compression is carried out of the preparation (2; 2 a - 2 b ) using a compacting piston (13) moving in the said enclosure (1) substantially perpendicular to the mean plane of the layer of the said pulverulent preparation (2; 2 a - 2 b ), characterized in that the hot compaction is carried out. 2 - Method according to claim 1, characterized in that one uses a compacting piston (13) equipped with a heating device (14). 3 - Method according to claim 2, characterized in that the temperature of the compacting piston (13) is adjusted to a value between 40 and 3ØØ ° C. 4 - Method according to one of claims 1 to 3, characterized in that a powdery cosmetic preparation is used which contains from 2 to 15% by weight of at least one binder. 5 - Method according to claim 4, characterized in that one uses (or) binder (s) conditioned (s) in microcapsules. 6 - Method according to one of claims 4 and 5, characterized in that, for a given powdery cosmetic preparation (2; 2 a - 2 b , one chooses a rate of binder less than or equal to that which would be chosen for a compaction without heat input. 7 - Method according to one of claims 4 to 6, characterized in that one uses at least one binder of hydrophobic nature. 8 - Method according to one of claims 1 to 7, in which the cup (4) is intended to constitute, with the compact cosmetic preparation (8; 8 a - 8 b ), a packaging element for the latter, characterized in that a cup (4) is used whose base (6) comprises at least one opening (9), the enclosure (1) being delimited in the region of said (or said) opening (s) (9) against a base-plate (3; 3a ) on which rests said cup (4), the surface of the compact cosmetic preparation (8; 8 a - 8 b ), which is accessible by said (or said) opening (s) (9), constituting, in the final packaging of the compact cosmetic preparation (8; 8 a - 8 b ), the surface for sampling, by the user, of said preparation. 9 - Method according to claim 8, characterized in that a cup (4) is used whose (or) opening (s) (9) is (or are) made (s) in the central part of the bottom ( 6), the border region of the compact cosmetic preparation (8; 8 a - 8 b ) being protected from the outside, in the final packaging by the peripheral zone of the bottom (6) of said cup (4). 10 - Method according to one of claims 8 or 9, characterized in that use is made against a base plate (3 a) whose surface coming opposite the (or each) aperture (9) of the bottom (6) of the cup (4) is slightly concave, to give the (or each) accessible area of the compact cosmetic preparation (8; 8 a - 8 b ), a slightly convex surface, projecting from the plane of the outer wall of the bottom (6) of the cup (4). 11 - Method according to one of claims 8 to 10, characterized in that there is, between the bottom (6) of the cup (4) and the base plate (3; 3 a ), a film flexible protection (11) capable of remaining integral with said cup (4) and its contents (8; 8 a - 8 b ) after compaction. 12 - Process according to claim 11, characterized in that a film is used (11) glued or welded to the outer edge of the bottom (6) of the cup (4) or a completely adhesive film (11) on its surface facing said bottom (6), said film (11) thus achieving the inviolability of the compact cosmetic preparation (8; 8 a - 8 b ) of the associated cup (4). 13 - Method according to one of claims 11 or 12, characterized in that one uses a film (11) tearable in one piece with a side gripping tab (12). 14 - Method according to one of claims 8 to 13, characterized in that there is, in the internal space of the enclosure (1), at least one bar (19) which separates powdery cosmetic preparations from different natures (2 a - 2 b ) and which rests on the counter-plate (3 a ) by crossing the opening (or at least one of the openings) of the bottom (6) of the cup, and which these compacts simultaneously preparations. 15 - Method according to one of claims 8 to 14, characterized in that a layer of liquid adhesive is deposited on the bottom (16) of a housing (15) capable of receiving by interlocking the cup (4) containing the compact preparation (8; 8 a - 8 b ), the bottom (6) of said cup (4) being turned outwards, and said glue is allowed to harden to ensure the fixing of the cup (4) on the bottom (16) of the housing (15) and on the lower internal edge of the side wall (17) of said housing (15). 16 - Method according to one of claims 8 to 1Ø, characterized in that there is, between the bottom (6) of the cup (4) and the base plate (3; 3a), a rigid cover capable of remaining integral with said cup (4) after compaction. 17 - Method according to one of claims 1 or 2, characterized in that the cup (4) and the cosmetic preparation are preheated before hot compaction (8; 8 a - 8 b ). 18 - Compact cosmetic preparation, obtained by the process according to one of claims 1 to 17.

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