Brush for applying a cosmetic product, related method and kit

Brush (10) for application of a cosmetic product, particularly a hair coloring and/or care product, comprising: —a handle (12)—a product applicator (14) projecting from the handle (12), the applicator (14) comprising crimped fibers (40). The crimped fibers (40) are between 0.25 mm and 0.45 mm thick and the crimp wave length is between 2.0 mm and 4.0 mm.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Phase filing under 35 U.S.C. § 371 of PCT/EP2017/069707 filed on Aug. 3, 2017; and this application claims priority to Application No. 16 57726 filed in France on Aug. 11, 2016. The entire contents of each application are hereby incorporated by reference.

BACKGROUND OF DISCLOSURE

Technical Field

This invention relates to a brush for application of a cosmetic product, particularly a hair coloring and/or hair care product, comprising a handle, a product applicator projecting from the handle, the applicator comprising crimped fibers.

This brush is designed to be manipulated by a user to apply a cosmetic product such as a hair coloring and/or hair care product on keratin fibers and particularly on the hair. The cosmetic product is generally in the form of a cream, a gel or a liquid.

The brush is designed for use by a professional in a salon to apply the product to a third party, or advantageously directly by the user in self-application, for example at home.

Background Art

More generally, a cosmetic product is a product as defined in EC Regulation No 1223/2009 of the European Parliament and the Council of Nov. 30, 2009, relating to cosmetic products.

Known application brushes comprise a handle and an applicator fixed to the handle that comprises separate tufts of straight fibers.

Before application, the user dips the applicator into a reservoir of a coloring product, and then brings the applicator to the hair to be colored so as to spread the product on the hair.

However, straight fibers tend to facilitate the accumulation of clumps of the product on the applicator while the product is being collected, and particularly between tufts. In particular, this leads to bad distribution of the product on the user's hair during application. In particular, this also leads to loss and wastage of formula that remains trapped between tufts of the brush after application.

EP893958 and EP923327 describe toothbrushes with crimped bristles.

BRIEF SUMMARY OF DISCLOSURE

One purpose of the invention is to obtain a brush for application of a cosmetic product that enables efficient collection of a fluid product on the applicator, particularly a hair coloring or hair care product that is conducive to a uniform deposit on keratin fibers and the scalp.

The purpose of the invention to achieve this is a brush for application of a cosmetic product of the type mentioned above, characterized in that the crimped fibers are between 0.25 mm and 0.45 mm thick and the crimp wave length is between 2.0 mm and 4.0 mm.

The crimped fibers thus have optimum characteristics for improving collection of the cosmetic product on the applicator and to efficiently distribute it in the applicator of the brush. Thus with the brush according to the invention, the quantity of formula collected can be 20% to 25% higher than with a brush with straight fibers for a coloring formula with a viscosity measured at 25° C. between 200 mPa·s and 3000 mPa·s, and preferably between 800 mPa·s and 1200 mPa·s, and particularly approximately 1000 mPa·s, these units being measured at a shear rate of 50 s−1.

The cosmetic product is placed uniformly between fibers and between tufts of fibers, avoiding the development of clumps of product on the applicator. The cosmetic product is delivered to keratin fibers and/or to the scalp with minimum losses. The deposit on keratin fibers and/or the scalp is then much more uniform than with straight fibers.

The brush according to the invention can include one or more of the following features, taken alone or in any technically possible combination:Advantageously, the crimp wave length of the crimped fibers is between 3.0 mm and 3.5 mm;

Such a wave length is particularly conducive to the distribution of product on the crimped fibers.Advantageously, the thickness of the crimped fibers is between 0.30 mm and 0.38 mm;

This thickness advantageously assures good elasticity of the crimped fibers and sufficient stiffness to facilitate displacement of the applicator on the user's hair and the resulting product application.Advantageously, the transverse amplitude of each wave of the crimped fibers is between 0.5 mm and 0.7 mm.

This characteristic assures that the crimped fibers remain flexible during application of the brush on the hair.Advantageously, the crimped fibers form discontiguous tufts distributed transversely across the handle.

In particular, the distribution of crimped fibers in the form of tufts facilitates mounting of the applicator on the brush handle using standard bristling methods and machines on the market.Advantageously, the ratio between the maximum thickness of each tuft and the maximum space between two adjacent tufts is between 1 and 2.

This ratio reduces liquid traps that can be formed between tufts of the applicator.Advantageously, the maximum space between two adjacent tufts is between 1.5 mm and 2.5 mm

This characteristic makes it possible to collect a sufficient quantity of product on the applicator.

Advantageously, the applicator has a beveled upper edge.

This cut makes application more ergonomic for the user, particularly during application on the temples. The pressure in the user's arms is lowered, which is more comfortable in the long term. Furthermore, this bevel cut comprises two different angles so that the precision of application can be modulated as a function of the application zone.Advantageously, each crimped fiber present is longer than 1 cm, preferably longer than 1.3 cm, and even more preferably longer than 1.8 cm.

This fiber length is particularly suitable for use of the brush with a fiber coloring and/or care product.Advantageously, the handle comprises a head defining two opposite dished gripping zones.

The opposite dished gripping zones optimize the grip obtained by a user's finger pads.

Another purpose of the invention is a method for applying a cosmetic product, including the following steps:impregnation of a brush as defined above with a cosmetic product, particularly a hair coloring and/or a hair care product;application of the brush applicator on the keratin fibers and/or on the scalp

Another purpose of the invention is an application kit comprising a brush as defined above and a cosmetic product.

The kit according to the invention can include one or more of the following features, taken alone or in any technically possible combination:the cosmetic product is a coloring and/or a care product for hair, keratin fibers and the scalp;the viscosity of the cosmetic product is between 200 mPa·s and 3000 mPa·s, preferably between 800 mPa·s and 1200 mPa·s, and more particularly approximately equal to 1000 mPa·s, measured at 25° C., with a shear rate of 50 s−1.

A cosmetic product with such a viscosity cooperates particularly advantageously with a brush as defined above to increase the amount of product collected, to avoid the formation of clumps of products, and to obtain a very uniform application.

DETAILED DESCRIPTION OF THE DISCLOSURE

A brush10for application of a cosmetic product is illustrated onFIG. 1.

The brush10is used particularly for application of a cosmetic product such as a coloring product and/or a care product, on a user's keratin fibers.

The keratin fibers of a user are advantageously the user's hair.

The viscosity of the cosmetic product at 25° C. is advantageously between 200 mPa·s and 3000 mPa·s, preferably between 800 mPa·s and 1200 mPa·s, and more particularly approximately equal to 1000 mPa·s. These units are measured at a shear rate of 50 s−1.

The viscosity of the products is measured at 25° C. using a Brookfield LVT viscometer equipped with a mobile M4 rotating at a speed of 12 revolutions per minute. The measurement is taken after 1 minute.

The cosmetic composition is for example made using a mix of a first cosmetic coloring product and a second cosmetic oxidizing product.

The first cosmetic product comprises an alkaline agent in a known manner. The alkaline agent is for example inorganic such as ammonia, or organic such as an organic amine, or hybrid such as an amine salt. It advantageously comprises at least one coloring agent such as an oxidation dye precursor, a direct coloring agent or mixtures thereof. It may contain at least one anionic, nonionic, cationic, amphoteric and/or zwitterionic surfactant.

The second cosmetic product contains at least one oxidizing agent, different from the oxygen in the air, such as hydrogen peroxide. It comprises at least one fat. The term “fat” refers to an organic compound insoluble in water at ordinary temperatures (25° C.) and at atmospheric pressure (760 mm of Hg) (solubility less than 5% and preferably 1% and even more preferably 0.1%). The fats are chosen for example from hydrocarbons, oils, fatty alcohols, esters of fatty acid and/or of fatty alcohols different from triglycerides and plant waxes, non-silicone waxes, silicones, and mixtures thereof.

With reference toFIGS. 1 to 3, the brush10comprises a handle12extending along a longitudinal axis A-A′ and an applicator14that projects longitudinally from the handle12.

The thickness of the handle12is less than 10 mm and in particular is between 4 mm and 6 mm. This limits the dimensions of the brush10.

The handle12comprises a stem16and a head18extending from the end of the stem16, the applicator14projecting from the head18.

Advantageously, the cross-section of the stem16of the handle12becomes smaller with increasing distance from the head18. In particular, the general shape of the stem16is in the form of a “V”.

The stem16extends between a free proximal end20and a distal end22from which the head18projects.

The proximal end20of the stem16is narrower than the distal end22. The step16is thus tapered at its proximal end20.

In this way, the user can use the proximal end20of the stem16to precisely select a particular lock of hair during application or to separate the lock of hair.

In the illustrated example, the head18of the handle12has a polygonal general shape, with an approximately rectangular distal region and a proximal region converging towards the stem16.

The head18of the handle12comprises an upper face24, two opposite principal faces26, and two side faces28opening up on the principal faces28. The lateral faces28converge towards the stem16of the handle12.

As can be seen onFIG. 2, the upper face24of the head18of the handle12extends perpendicular to the longitudinal axis A-A′.

The upper face24defines several holes30that contain tufts of the applicator14. Each hole30projects along a longitudinal direction of the handle12.

Each hole30may for example have a depth of between 5 mm and 7 mm, for example a depth equal to 6 mm.

In the example shown, the upper face24of the head18comprises at least one row of identical holes30distributed over the entire width of the head18. The number of holes is more than 5 and for example is between 8 and 12.

Each principal face26of the head18of the sleeve12delimits a dish shaped gripping zone32. The surface area of each gripping zone32is at least 60% of the total surface area of the principal face26.

Preferably, each gripping zone32has a depth of more than 0.5 mm, particularly between 0.8 mm and 1.2 mm.

In this example, the stem16and the head18of the handle12are made in a single-piece from the same material. For example, the handle12can be made of plastic, particularly polypropylene or polyethylene.

The applicator14projects from the handle12and extends in the same plane as the handle12. It comprises a proximal end34fixed in the handle12. It defines a free distal edge36located at a distance from the handle12.

Advantageously, the free distal edge36of the applicator14is beveled. For example, the angle α formed by the beveled cutout is between 1° and 20°, particularly between 5° and 15°, and more particularly between 8° and 12°, for example close to 100, from the upper face24of the head18of the handle12.

The ratio of the length between the longest fibers and the shortest fibers must be small, for example between 1.05 and 1.5, to obtain a uniform application quality of the formula on the hair and/or on the scalp.

The applicator14comprises several tufts38each composed of a group of crimped fibers40. The tufts38are transversely distributed on the upper face24of the head18of the handle12.

The maximum thickness of each tuft38taken perpendicular to the A-A′ axis is less than 5 mm, and is advantageously between 2.5 mm and 3.5 mm.

There is a maximum space between consecutive tufts38taken perpendicular to the A-A′ axis, equal to between 1.5 mm and 2.5 mm.

The space between two consecutive tufts38is equal to the maximum distance separating two corresponding crimped fibers40of two consecutive tufts38, located facing each other and closest to each other.

Advantageously, the space between two consecutive tufts38is between 1.8 mm and 2.2 mm. As a result, the tufts38define a space between tufts adapted to hold an optimum quantity of cosmetic product.

The ratio between the diameter of each tuft38and the space between two consecutive tufts38is between 1 and 2, and particularly between 1.4 and 1.6. The appearance of liquid traps on the applicator14is thus limited.

The proximal end of each tuft38defining the proximal edge of the applicator14is housed in a corresponding hole30in the upper face24of the head18of the handle12. Thus there is one tuft38in each hole30.

Each tuft38comprises several crimped fibers40, arranged at random in the tuft38.

Advantageously, each tuft38comprises a number of crimped fibers40equal to between 30 and 50 fibers, and preferably between 38 and 42 fibers.

An example of a crimped fiber40is shown inFIG. 4.

Each crimped fiber40has a thickness e equal to between 0.25 mm and 0.45 mm. Thus, the fibers40are springy and yet sufficiently stiff to facilitate application on the hair.

Preferably, the thickness e of each crimped fiber40is between 0.30 mm and 0.38 mm, for example approximately equal to 0.35 mm.

Preferably, the thickness of each crimped fiber40is constant over the entire length of the crimped fiber40such that the cut finish of the crimped fibers40at the top edge36is rough. As a result, the product is retained on the top edge36of the applicator14. This prevents the cosmetic product from running along the brush10.

The length of each crimped fiber40is more than 15 mm, and particularly between 20 mm and 28 mm.

The crimp wave length B of each crimped fiber40is between 2 mm and 4 mm. As a result, the product is efficiently distributed on the applicator14.

Advantageously, the crimp wave length B of each crimped fiber40is between 3.0 mm and 3.5 mm, for example equal to 3.2 mm;

The crimp wave length B is defined with reference toFIG. 4as the distance separating two successive peaks S1, S2of the crimp located on the same side of the longitudinal median axis B-B′ of the crimped fiber40.

Each crimped fiber40has a crimp amplitude A equal to between 0.5 mm and 0.7 mm. Thus, the flexibility of the crimped fibers40is adapted to application on hair.

For example, the crimp amplitude A of each crimped fiber40is equal to 0.6 mm.

“Crimp amplitude” means the “peak to peak” amplitude corresponding to the distance measured between two successive summits S2, S3of the crimp, perpendicular to the B-B′ axis.

The crimped fibers40are preferably made from plastic, for example polyamide, and particularly PA6 nylon.

A method for applying cosmetic product using the brush10will now be described.

In a first step, the user prepares a cosmetic product to be applied to keratin fibers, for example coloring product and/or a hair care product.

He or she then dips the crimped fibers40of the applicator14of the brush10into the cosmetic product and impregnates the applicator14of the brush10with cosmetic product.

The cosmetic product penetrates between the crimped fibers40of the applicator14. It is naturally and uniformly distributed between the crimped fibers40.

The user then places the applicator14impregnated with cosmetic product on the hair and/or the scalp.

The user uses the distal end22of the stem16of the handle12to separate the lock of hair or the hair parting, so as to apply the cosmetic product along the length of a lock of hair of for application on the root of the hair.

The user makes a direct application on the temples or on the root by holding the handle12by the head18and squeezing opposite gripping zones32with his or her fingers.

FIGS. 5 and 6show a comparative illustration of the distribution of cosmetic product on the applicator14as described above and on an applicator42according to another embodiment.

The applicator14illustrated onFIG. 5comprises crimped fibers40as described above. The cosmetic product is then distributed uniformly between the crimped fibers40.

The applicator42on the brush according to the state of the art illustrated inFIG. 6, comprises straight fibers44. The cosmetic product is not retained optimally by the straight fibers44and product clumps46form between the tufts38of straight fibers44.

For equal thickness, crimped fibers40are more diffuse than straight fibers44and pick up more cosmetic product on the applicator14than straight fibers44, with 20% to 25% more collected in the example presented in the figures.

As a variant, the handle12can have a different shape and/or the number of tufts38and the number of crimped fibers40per tuft38can be different, without changing the function and performances of the brush10.

The brush described above has beneficial properties for the user, particularly when the user applies the product himself or herself at home.

In particular, the brush facilitates collection of the cosmetic product on the applicator while preventing running. Furthermore, the brush distributes the product uniformly on the applicator to obtain an optimum deposit of the product on the user's hair. The brush is both flexible and robust to make it more comfortable and to achieve efficient application on hair. Furthermore, the brush according to the invention is ergonomic and precise and is more comfortable for the user throughout the application duration.

In one variant, the brush is packaged in the form of an application kit comprising the brush10as described above, at least one cosmetic product received in a receptacle and packaging containing the brush10and the receptacle or each receptacle containing the cosmetic product.

Advantageously, the kit comprises a pair of gloves to protect the user's hands during application of the cosmetic formulation, and/or a comb to prepare the hair and/or a bowl to prepare the cosmetic product to be applied to the user's hair.

Due to its small thickness and its large flat surface, it is easy to put the brush in a kit and many brushes can be carried by stacking them.

As a variant, the crimped fibers are mounted in the form of strips with a rectangular cross-section instead of tufts with a circular cross-section.

As another variant, the crimped fibers can be mounted with a twist, the bristles being glued.