Cosmetic Composition Containing Microencapsulated Solvents For Nail Enamel

Abstract

A cosmetic composition for removing nail enamel comprises a shaped cosmetic applicator containing a multiplicity of rupturable microcapsules, a portion of which contain a first solvent for the enamel and the remainder containing a second solvent exhibiting a solvent action on the enamel greater than said first solvent and a perfume to mask the odor of said solvents.

Description

The present invention relates to a solvent cosmetic composition for nail enamel, characterized in that the solvent activity of the solvent cannot be brought into effect until mechanical pressure has been exerted on the composition at the moment of its application.

Solvents or solvent compositions for nail polish are well known. However, these solvent compositions have numerous disadvantages in use because they are generally liquid and have an unpleasant odor. Additionally, these compositions are stored in bottles and because of their solvent property, the obtaining of a complete seal which is necessary for such bottles presents obvious difficulties that are further increased by the fact that an applicator brush must generally be provided. It should also be noted that the use of these solvents is most often effected with a great excess of the product because of the difficulty of application with a brush, the excess being bothersome because of the disagreeable odor of the utilized compounds. Moreover, the use of an excess of solvent brings the solvent into contact with the skin around the nails, on which it has a drying effect. Finally, the solvent mixture evaporates rather rapidly from the bottles which are difficult for the user to close tightly.

The present invention is intended to obviate the above mentioned disadvantages, particularly those resulting from storage, the disagreeable odor of the solvent, its use in excessive quantities that are difficult to control, and its gradual evaporation from the container.

The present invention relates to a new solvent composition for nail enamel, containing all the usual active elements of a nail enamel solvent, but whose solvent action cannot occur until sufficient mechanical pressure has been exerted at the moment of application of the said composition.

The present invention likewise relates to the process of releasing the solvent agent at the moment of its application.

The invention also refers to certain forms of storage for the said cosmetic solvent composition that are especially advantageous.

The invention is also concerned with the preparation of the above mentioned cosmetic compositions.

According to the invention, it has been found possible to prepare solvent cosmetic compositions without the above indicated drawbacks, in that the solvent agents contained in the vehicle of these compositions can be physically separated from the rest of the components by the well-know technique of microencapsulation which consists in surrounding the solvent agents, divided into small liquid particles, by a suitable envelope.

The process of microencapsulation itself is not part of the present invention since the microencapsulation of the solvents is effected separately and the microcapsules are then introduced into a suitable cosmetic vehicle. Of course, all the other ingredients of the above mentioned cosmetic preparations can also be microencapsulated, including perfumes which mask the disagreeable odor of the solvent. Such perfumes may be contained in separate microcapsules or in the microcapsules that contain the solvents.

According to the invention, the new solvent cosmetic compositions are constituted by a vehicle which may be in one of a variety of forms such as a liquid, a thickened liquid, a cream, an emulsion, a powder or a pencil, containing all the conventional ingredients of the said solvent compositions as well as possible thickeners, provided, however, that solvent particles distributed in these compositions have the characteristic that they are surrounded by an envelope that cannot be destroyed by contact with the vehicle of the solvent composition. These envelopes can, however, be torn by a sufficient mechanical pressure in spreading.

The microcapsules, here designated by C, incorporated in the cosmetic composition contain substantially solvent agents such as ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate, butyl propionate, ethyl lactate, butyl stearate, associated or not with oils or with high boiling point compounds e.g., ethylene glycol monoethylether, diethylene glycol monoethylether, .gamma.-valerolactone, castor oil, olive oil, etc.

The said microcapsules are prepared by conventional processes, but according to the invention they are characterized by the nature of their envelope, their dimensions and their thickness or by the ratio R between the weight of the envelope and the total weight of the microcapsule.

The compounds which form the said envelopes, here designed by E, can particularly be any one of the following:

polystyrene/maleic acid

polyethylene and polyethylene/ethyl cellulose mixtures

polyurethanes

polyesters

gelatin

natural waxes such as carnauba wax, beeswax, candelilla wax, Japan wax

paraffin wax

polyamide

formaldehyde urea

acetal homopolymers and copolymers

casein

epoxy resins

polypropylene

cellulose acetophthalate

Microcapsules are used whose dimensions vary from 10 to 600 microns, although by preference microcapsules of 20 to 250 microns are used. The thickness of the envelopes is also variable according to their mechanical strength, the ratio R usually being from 1 to 10 percent and preferably 3 to 6 percent by weight. However, the resistance of the microcapsules to mechanical pressure must always be sufficient so that, depending upon the kind of storage, the microcapsules will not be torn before they have been spread on the nail from which the film of enamel is to be removed.

According to a modification of the present invention, two solvents or solvent compositions are used which have a different solvent strength, contained respectively in microcapsules C.sub.1 surrounded by envelopes E.sub.1, and C.sub.2 surrounded by envelopes E.sub.2. The capsules here designated C.sub.1 contain a first solvent agent which has a moderate solvent action and capsules C.sub.2 contain a second solvent whose solvent properties are definitely stronger, the said second solvent agent having a delayed action with reference to that of the first. The delayed action mechanism is obtained for example by the fact that for envelopes E.sub.1, E.sub.2 of the same kind and capsules of the same dimensions, envelopes E.sub.2 are thicker than envelopes E.sub.1. However, other mechanisms may also be employed, e.g., incorporation in capsules C.sub.1 of an agent that is inert with reference to envelopes E.sub.1 but which destroy envelopes E.sub.2.

Microcapsules C.sub.2 may additionally contain a perfume whose release indicates that they have been opened.

The preparation of the cosmetic compositions of the invention is effected as follows:

In a first stage, a microencapsulation of the solvents or solvent compositions is effected according to any known microencapsulation process, care being taken however to select the type of membrane from the compounds mentioned above.

In a second stage, the cosmetic compositions themselves are prepared from conventional ingredients with capsules prepared in the first stage. Operation must always be such as to avoid rupture of the microcapsules. In a general way, the microcapsules can be introduced into the cosmetic vehicle at any moment of its preparation. However, a preferred method of the present invention resides in preparation first of one or more pre-mixtures being determined in appropriate fashion depending upon the nature of the composition and of the microcapsules to be introduced.

To attain a good homogeneity and a good distribution of the microcapsules in the cosmetic composition of the invention, the vehicle density of the composition is preferably adjusted to the density of the microcapsules that are utilized by introduction of an excess of one of the ingredients or of a suitable substance. However, it is possible to operate in reverse, adjusting the density of the microcapsules which contain the solvent agents to the density of the vehicle of the composition. It is also possible to select the microcapsules and choose those whose density is appropriate, since this density varies as a function of the degree of filling of the said microcapsules and of ratio R defined above.

The solvents and solvent compositions of the invention may be in the form of a cream, an emulsion, a powder, a pencil and also of a flexible support of some kind such as a paper napkin or "blotter" type, fabric or a porous synthetic material, containing microcapsules.

In any case, presentation as a pencil is especially advantageous. In this case, the pencil channel ends in a small spatula with a triangular tip whose plane is perpendicular or inclined with reference to the axis of the above mentioned channel, said spatula serving to spread the cosmetic composition on the nail from which the coating of nail polish that covers it is to be removed, the pencil then being stoppered by a small movable cap after use. No matter what its form of packaging, the solvent composition of the invention is thus utilized exactly in the desired amounts, it does not present the disagreeable odor of the old compositions because of the microencapsulation, or else this odor is very much attenuated. Moreover, the presence of a perfume either in the vehicle of the cosmetic composition or in the capsules containing the solvent agent, makes it possible in all cases if desired to obtain an agreeable perfumed product.

According to a modification, microcapsules can be used which are coated inside by thin envelopes here designated E'. The said thin envelopes are inert with respect to the agent or to the solvent mixture and/or coated on the outside by thin envelopes here designated E", which envelopes are inert with respect to the vehicle of the solvent cosmetic composition. These envelopes associated with the above mentioned envelopes of the microcapsules make it possible to make use in the preparation thereof of compounds which may not have the desired mechanical properties or other properties necessarily, which permits more ready production of the microcapsules of the invention. Envelopes E' and E" are prepared moreover with polymers and colloids that have already been mentioned.

The following non-limiting examples in which the parts and percentages refer to weight, are again by way of illustration so as to permit a better understanding of the present invention.

EXAMPLE 1

Liquid solvent

A cosmetic composition is prepared which is constituted by a dispersion of microcapsules in an aqueous phase, optionally in the presence of thickeners, to obtain dropwise application. The composition comprises an aqueous phase:

carboxymethyl cellulose 2.5 water 97.5

The capsules contain the solvent agent and a perfume, in the form of the following mixture:

acetone 84.8 ethylene glycol monoethylether 10 butyl stearate 5 perfume 0.2

The capsule envelope is constituted by a natural wax, an acrylic resin or casein.

The capsule dimension is from 50 to 250 microns. The composition is prepared by dispersing the capsules in the aqueous phase.

To use the composition, a drop is allowed to fall on the nail from which the polish is to be removed and rubbed with a small wad of hydrophilic cotton or a cloth to crush the capsules, releasing their solvent mixture.

EXAMPLE 2

Solvent paste

A solvent cosmetic composition constituted as a paste and containing two kinds of solvent capsules C.sub.1 and C.sub.2 is prepared.

Aqueous phase:

The aqueous phase is constituted by:

ethyl cellulose 3 stearic acid 10 20% ammonia solution 4

water in sufficient quantity to obtain a paste of the desired consistency.

Capsules:

Capsules C.sub.1 contain the following solvent mixture:

.gamma. valeroacetone 50 ethylene glycol monoethylether 15 ethanol 35

The envelope of the capsules C.sub.1 is constituted by natural wax, their dimension being from 150 to 250 microns.

Capsules C.sub.2 contain the following solvent mixture:

ethyl acetate 50 acetone 49.8 perfume 0.2

The envelope of the capsules C.sub.2 is constituted by a styrene polymer/maleic acid, completely hydrolyzed, the dimension being from 50 to 100 microns.

Capsules C.sub.1 and C.sub.2 are incorporated in equal quantities in the previously prepared paste and the whole is then stored in a jar or in a flexible tube with a spatula applicator.

Release of the solvents is effected as indicated in the preceding description.

EXAMPLE 3

A solvent cosmetic composition is prepared in the form of a shaped cosmetic applicator, i.e., a pencil constituted in the following way:

A cosmetic vehicle is used which contains:

beeswax 10 ozocerite 24 carnauba wax 8 paraffin 8 lanolin 10

All the above constituents are melted to prepare the pencil core whose hardness may be modified by appropriate addition of paraffin oil.

The capsules contain the solvent agent in the form of the following mixture:

ethyl acetate 40 acetone 30 amyl acetate 5 ethylene glycol monoethylether 10 castor oil 14.8 perfume 0.2

The envelope of the microcapsules is constituted particularly of polyamide, polyethylene/ethyl cellulose or polpropylene, the dimension being 20 to 100 microns.

The said capsules are dispersed in the above cosmetic vehicle. Before it sets, it is molded to form a core, using a press. This core is utilized to constitute a pencil which, because of its form, allows accurate application of the solvent paste, the microcapsules then being crushed by simple mechanical pressure on the nail from which the colored polish is to be removed.

EXAMPLE 4

Textile or paper for solvent microcapsules

Microcapsules containing the following mixture as solvent agent are prepared:

ethyl acetate 60 diethylene glycol monoethylether 34.8 castor oil 5 perfume 0.2

The compounds forming the envelopes of the microcapsules are of natural wax, an acrylic resin, casein, hardened gelatin, or polyethylene/ethylcellulose. Dimension of the capsules is between 50 and 250 microns.

The said microcapsules are projected onto a fabric or paper support preliminarily treated in conventional fashion to allow adherence, thus providing another example of a shaped cosmetic applicator. Fabrics or papers are thus obtained that are solvents for the lacquer on the nails. It is then sufficient to rub the support thus prepared locally on the nail to burst the capsules adhering to the said support and thus to release the solvent contained therein.

The scope of the invention is defined in the following claims:

Claims

What is claimed is:

1. A cosmetic composition for removing nail enamel comprising a shaped cosmetic applicator support adapted to be applied locally to the nail and containing a multiplicity of rupturable microcapsules, a portion of said microcapsules encapsulating a first solvent for said enamel, which otherwise has a disagreeable odor, evaporates excessively on storage and exhibits a moderate solvent action on said enamel, the remainder of said microcapsules encapsulating (1) a second solvent for said enamel which otherwise has a disagreeable odor, evaporates excessively on storage and exhibits a solvent action on said enamel greater than said first solvent and (2) a perfume effective to mask the otherwise disagreeable odor of said solvents, said portion of microcapsules containing said first solvent being readily ruptured by mechanical pressure so that the solvent action of said first solvent cannot occur until sufficient mechanical pressure has been exerted at the moment of application of said composition, said remainder of microcapsules containing said second solvent and perfume being ruptured by mechanical pressure greater than that necessary to rupture said portion of microcapsules containing said first solvent so that the solvent action of said second solvent and the masking action of said perfume occurs after release of said first solvent whereby release of said perfume indicates that said remainder of said microcapsules has been ruptured, the density of said microcapsules being substantially equal to the density of said applicator to provide uniform distribution of said microcapsules in said composition, said walls of said microcapsules being inert to said solvents and said perfume and being formed of a material selected from the group consisting of polystyrene/maleic acid, polyethylene, polyethylene/ethyl cellulose mixture, polyurethane, polyester, gelatin, natural wax, paraffin wax, polyamide, urea formaldehyde, acetal homopolymers and copolymers, casein, epoxy resin, polypropylene and cellulose acetophthalate.

2. The cosmetic composition of claim 1 wherein said shaped cosmetic applicator is a textile fabric or paper support, said microcapsules being adhered thereto.