EP0937424B1 - Brush for nail varnish or the like - Google Patents

Description

The invention relates to a brush for applying varnish to nails, or the like, of the kind which have bristles forming a tuft, attached to the end of a rod and oriented substantially in the axial direction of the rod.

FR-A-2 687 055 shows a brush of this type which allows, with conventional nail varnish compositions, to perform a precise and rapid application of the varnish. In particular, with such brush, it is no longer necessary to dive many times brush in the container to make up a nail because the load of product taken with the brush is relatively high.

The classic nail polish compositions, currently used, have viscosities of around 200 centipoise to 400 centipoise (200 to 400 cps). However, varnish compositions with developing nails have higher viscosities, notably around 600 cps (centipoise). Still compositions more viscous are also envisaged.

It appeared during tests that the nail varnish brushes known, in particular a brush such as that mentioned above, does not not entirely satisfactory for applying compositions of varnish whose viscosity is higher than the viscosity range classics. In particular, the brushes known to date do not give complete satisfaction in applying varnishes with a viscosity of in the order of, or greater than, 600 cps.

The object of the invention is, above all, to provide a varnish brush with nails that allow, even with high viscosity varnishes, especially above 600 cps, apply the product in good conditions, while being usable for applying nail polish classic.

The invention also aims to provide a brush which, while by meeting the requirement set out above, remains of a manufacture simple and economical, and classic use.

To solve this problem, according to a first solution, a brush according to the invention, for applying nail varnish or a analogous product, comprising hairs forming a tuft, obtained at from a bundle of substantially parallel hairs, folded in half about mid-length, the hairs being attached to the end of a rod by engagement, with tightening, of the folded part of the tuft of hairs in a housing opening at the end of the rod, the bristles having cross sections admitting a circumscribed circle of diameter constant, this brush being characterized by the fact that the bristles of the tuft are chosen from at least two groups, the hairs of one group being arranged to have mechanical bending behavior different from that of the hairs from the other group so that when bending and tightening of the different groups of bristles, these groups give an airy and spreading brush tuft with spaces between relatively large hairs, favorable for good capillarity for varnishes whose viscosity can vary over a wide range.

According to a first possibility, the hairs of a group are produced in a material different from the hairs of another group, these materials different with different coefficients of elasticity mechanical behavior different from the hair groups, the coefficient of elasticity of the material of a pile of a first group varying from 10% to 200% compared to the elasticity coefficient of the matter of a hair from another group.

According to another possibility which can be combined with the previous, the hairs of a group have a cross section shape different from the hairs of another group, these differences in shape leading to differences in flexural strength, even if the material of the hairs of the different groups is identical.

A first group of hairs can comprise 5 to 95% of the total number of brush hairs, second group, or set of the other groups, being made up of the complement, namely 95 to 5% relative to the total number of hairs.

The brush may have a third group of bristles different, the number of which can vary from 90% to 10% compared to the total number of brush hairs.

The most flexible bristles can be made of polyamide, for example the polyamide known under the trade name Tynex from Dupont de Nemours, or in polyether block ether or in polyester elastomer. The material used for the bristles less flexible can be chosen from the group: Rilsan, polyamide, polyethylene, polytetrafluoroethylene, polyvinylidene fluoride, polyacetate, polyethylene terephthalate.

To solve the same problem, according to a second solution, we can also use a housing of particular shape: the invention therefore also relates to a brush for applying varnish to nails, or the like, having bristles forming a tuft attached to the end of a rod by engagement of the tuft of hairs in the housing opening at the end of the rod, the hairs having cross sections admitting a circumscribed circle of diameter constant, this brush being characterized in that said housing has a flared shape whose large base is located at the end of the stem, this shape giving an airy brush spread and spread with relatively large spaces between the hairs, favorable for good capillarity for varnishes whose viscosity can vary over a range extended.

The tuft of the brush can be obtained from a bundle of substantially parallel bristles, folded in half approximately halfway down, the folded part of the tuft of hairs being engaged with clamping in the rod housing.

In addition, the cross section of the end of the rod can have any shape. It can, for example, be round, square, rectangular, triangular, oval or cruciform.

In particular, the housing can be in the form of a truncated cone, pyramid, funnel; it can also be cylindrical with a shoulder defining an area of diameter larger than the area of bottom of the housing where the implantation of the tuft takes place.

According to the second solution, the hairs can be identical or different. They are made in particular of synthetic material or natural. The natural material can normally be chosen from natural bristles, preferably of animal origin. Matter synthetic can be chosen from the group formed by polyamides, polyesters, polyether-block amides, polyethylenes, polytetrafluoroethylenes, polyvinylidene fluorides, polyacetals, polyethylene terephthalates.

Preferably, bristles are used whose diameter is chosen to 11 hundredths to 40 hundredths of a millimeter, and preferably 14 hundredths to 17 hundredths of a millimeter. The hairs are preferably hollowed.

The brush of the invention is suitable for applying, in particular, varnishes whose viscosity is in the range of 200 to 2,000 cps, limits included. In practice, the brush of the invention allows a correct application of liquid product whose viscosity may vary in a range from about 1.2 to about 3,500 cps.

In a manner known per se, the folded area of the hairs can be held, in the rod, by a staple forcefully pressed into the rod housing.

The length at which the bristles of the brush protrude beyond the end of the rod can be between 12 and 30 mm, limits included.

The diameter of the circle circumscribed to the cross section of a hair is between 3/100 mm and 18/100 mm, limits included; this diameter is the same for all the bristles of the same brush.

The shape of the cross section of a hair is chosen, in particular among the following forms: solid circular, circular hollow, horseshoe, V-shaped, flat, cruciform, or with grooves capillaries.

Adjuvants modifying the surface condition and the tension may be incorporated into the material of the brush bristles.

The invention consists, apart from the arrangements set out above, in a number of other provisions which it will be more Explicit question below about examples of realizations described with reference to the attached drawing, but which are in no way limiting.

Figure 1 of this drawing is an elevational view of a paintbrush nail varnish according to the invention.

Figure 2 is a schematic view on a larger scale, in partial axial section from the end of the stem provided with the tuft fur.

Figure 3 is a view of the bundle of hairs substantially parallels used to make the brush.

Figure 4 is a schematic view illustrating the engagement of the tuft of hairs folded in the stem housing.

Figure 5 is a schematic view, on a larger scale, of brush hairs belonging to two different groups.

Figures 6 to 11 are diagrams of different sections possible cross hairs, inscribed in a circle of diameter constant.

Figures 12 and 13 show, in elevation, on a large scale, two possible shapes for the tip of the brush.

Figure 14 is a side view of a possible end for the tip of the brush.

Figures 15 to 17, finally, illustrate cross sections possible for housing the end of the brush receiving the tuft of hairs.

Referring to Figure 1 of the drawings, we can see a brush 1 for the application of nail polish comprising a tuft 2 of hairs 3, 4 fixed to the end of a rod 5, and oriented substantially along the axial direction of the rod. A cylindrical sleeve 6 is integral with the end of the rod 5 opposite the tuft 2, and engaged in the muff. This cylindrical sleeve 6 serves as an operating member of the paint brush; it also serves as a stopper intended, for example, to be screwed onto the neck of a bottle of varnish.

The tuft 2 is obtained from a bundle 7 (FIG. 3) of hairs 3, 4 substantially parallel, folded in half about halfway as illustrated in Figure 4. The tuft 2 is attached to the end of the rod 5 by engagement, with clamping, of the folded part 8 (see figure 2) tuft of hairs in a housing 9 formed by a blind hole opening at the end of the rod 5.

All the bristles 3, 4 have a cross section admitting a circumscribed circle C (see Figures 6 to 11) of constant diameter.

The bristles 3, 4 are chosen from at least two groups: hairs 3 of a group are arranged to have a behavior bending mechanics different from that of bristles 4 of the other group so that when folding and tightening the different groups of hairs, these groups give an airy and spreading tuft 2.

In particular, a bristle 3 (see FIG. 5) for example more rigid than a bristle 4 will form, during bending, a "V" more open than that formed by a bristle 4. Thus a relatively large gap i is created between the end of the bristle 3 and the neighboring end of a bristle 4. This interstice naturally decreases from the free end of the bristles to the fold zone 8. The existence of the gap between the bristles 3 and 4 is favorable for good capillarity for varnishes of high viscosity.

The aeration and spreading of the tuft 2 of hairs results from the combined effect of folding the bundle 7 substantially at mid-length and engagement with tightening of the folded part 8 in the housing 9. The cooperation of a zone of the tuft 2 with the walls of the housing 9, and the tightening of this tuft in the housing, intervene in the formation of the plume of the tuft 2.

Generally, the tuft 2 is produced as illustrated in the Figures 3 and 4, placing the middle zone of the beam 7 on the entry of the housing 9 of the rod 5. A staple 10 is engaged around the area located substantially mid-length of the beam 7 and is pressed into the housing 9 by causing the bristles 3, 4 to come back into abutment against the edge of the housing 9. During this operation, the clip 10 is folds back so as to clamp the bristles and is forced into the rod 5.

The clip 10 is made from a metal wire, bent into a U, whose section can be circular, rectangular flat, or square. The diameter or the long side of the wire section is advantageously between 0.2 mm and 1.5 mm.

The bottom zone 9 a (FIGS. 2 and 15) of the housing 9, where the stapling takes place, can be cylindrical of revolution, while the upper part 9 b of the housing located beyond this cylindrical zone has a flared shape, frustoconical of revolution whose large base is located at the open end of the housing 9. The tuft 2 of the brush, located in such a housing, has a frustoconical shape with a substantially circular base.

Other forms are possible for housing. For example, as illustrated in FIG. 16, the upper part 9 ' b (flared or not) may have a bean or banana-shaped section. According to another possibility, the section of the upper part has an oval shape, a flattened rectangular shape, or a cross shape.

FIG. 17 illustrates an advantageous variant of the shape of the housing 9 ". There is, in the bottom of the housing, a cylindrical part of revolution 9" a . The flared upper part 9 " b has a substantially flattened rectangular shape, the long sides of which are curved to present an outward concavity. The end of the rod 5 therefore has two concave faces c forming, in a way, a channel for the flow of product from the rod to the tuft of the brush.

According to the different shapes of the housing section 9, 9 ', 9 ", and in particular of the flared part, the contour of the tuft 2 is modified in consequence and reproduces, on a larger scale, substantially the shape of the housing section.

To ensure a different mechanical behavior when bending of the two hair groups 3 and 4, according to a first possibility, we chooses for each group of hairs 3, 4 different materials with different elasticities. The elasticity of the material is characterized by the modulus of elasticity or Young's modulus. elasticity of the material of a pile 3 of the first group preferably varies from 10% to 200% compared to the elasticity of a hair 4 of the second group.

Under these conditions, the bristles 3 and 4 made of different materials, even if they have sections of identical shape, inscribed in a circle of the same diameter, will have a different mechanical behavior at the bending.

The most flexible bristles can be made of polyamide, for example the polyamide known under the trade name Tynex from the Dupont de Nemours company, or in polyether block ether, or in polyester elastomer. The less flexible hairs can be made of a material chosen from the group: Rilsan, polyamide, polyethylene, tetrafluoroethylene, polyvinylidene fluoride, polyacetate, polyethylene terephthalate.

Examples of brushes made with bristles of different materials with the same circumscribed circle diameter.

A first brush was made with bristles of diameter 8/100 mm with 50% bristles in Rilsan and 50% bristles in PA6.10 (polyamide 6.10).

Another example is a brush made with 30% bristles Rilsan diameter 8/100 mm and 70% PA6.6, also diameter 8/100 mm.

Another example corresponds to 30% of PET hair (polyethylene terephthalate) with a diameter of 10/100 mm and 70% hairs PA6.12 also 10/100 mm.

Alternatively, which can be combined with the previous, we obtain a mechanical behavior to bending different from a group of bristles 3 compared to a group of bristles 4 in giving the cross section of hairs different shapes leading to differences in flexural strength.

For example, the least flexible bristles 3 will have a cross section full circular as shown in Figure 6, while the bristles more hoses 4 will have a hollow circular section such as that of the Figure 7, the outer diameter of the bristles being the same.

Other forms of sections can be combined, for example a horseshoe-shaped section such as that of FIG. 8, a V-shaped section such as that of Figure 9, or a rectangular flat section such as that of figure 10, or a cruciform section such as that of figure 11.

The diameter of the circumscribed circle C of a hair is between 3/100 mm and 18/100 mm.

The first group of hairs 3 constitutes from 5 to 95% relative to to the total number of brush hairs, while the second group of bristles 4, or all of the other groups, is constituted by the complement, that is to say 95 to 5% relative to the total number of hairs.

An example of a brush, with two groups of material bristles different and with a different section shape, was made with 50% of Rilsan FAC bristles (horseshoe section) and 50% PA6.12 bristles with a full circular section, the diameter of the circle circumscribed at bristle sections being 8/100 mm.

The section of the bristles may have at least one groove capillary, not shown in the drawing.

The length L (Figure 2), the bristles protrude beyond the end of the rod 5, or apparent length of the bristles, is advantageously between 12 and 30 mm. In the case of a housing 9 with a circular section, the diameter of the housing section can be approximately 2 mm. With a length L of approximately 13 mm and bristles with a diameter of 8/100 mm, the diameter d (FIG. 2) of the large base of the plume of bristles of the brush is greater than 4 mm, while in similar conditions, a conventional brush would have a smaller end diameter d , for example of the order of 2.5 to 3 mm.

The end of the brush can be straight, orthogonal to the axis of the rod as illustrated in 11 in FIG. 12, or may have a convex curved shape 12 as illustrated in FIG. 13. According to a other possibility, the end of the brush can be cut along a plane 13 inclined relative to the axis of the rod, as illustrated on the figure 14.

To solve the problem of the invention, according to a second solution, one can use only the particular shape of the housing 9. In this case the hairs, forming a tuft, are fixed at the end of the rod 5 by engagement of the tuft of hairs in the housing 9. The hairs 3, 4 may not be folded in half about halfway. The housing 9 has a flared shape 9b whose large base is located at the end of the rod 5. This shape 9b gives a tuft of brush airy and spread out with relatively large spaces between the hairs, favorable to good capillarity for the varnish whose viscosity can vary over a wide range.

In addition, the cross section of the end of the rod 5 can have any shape. It can, for example, be round, square, rectangular, triangular, oval or cruciform.

In particular, the housing 9 can be in the form of a trunk of cone, pyramid, funnel; it can also be cylindrical with a shoulder defining an area of diameter larger than the bottom zone 9a of the housing where the tuft implantation takes place.

According to the second solution, the bristles 3, 4 can be identical or different. They are made in particular of synthetic material or natural. The natural material can normally be chosen from natural bristles, in particular of animal origin. Matter synthetic can be chosen from the group formed by polyamides, polyesters, polyether-block amides, polyethylenes, polytetrafluoroethylenes, polyvinylidene fluorides, polyacetals, polyethylene terephthalates.

Preferably, bristles are used whose diameter is chosen to 11 hundredths to 40 hundredths of a millimeter, and preferably 14 hundredths to 17 hundredths of a millimeter. The hairs are preferably hollowed.

Adjuvants can be incorporated into the material surface condition and surface tension modifiers.

The mixed bristles of the brush can be straight or wavy. The bristles can be ground or tapered. The brush may have hairs of different levels.

• une différence de tension superficielle entre les poils des différents groupes ;
• un écartement des poils plus important et donc une capillarité améliorée et une rétention plus importante ce qui conduit à une plus grande autonomie.

A brush according to the invention has:

• a difference in surface tension between the hairs of the different groups;
• greater hair spacing and therefore improved capillarity and greater retention which leads to greater autonomy.

Such a brush can apply liquids of the consistency of alcohol to creamy consistency. In other words, such brush can apply liquid products whose viscosity varies in a range of about 1.2 to 3,500 cps.

The brushes of the invention will make it possible to develop varnish compositions having viscosities higher than conventional viscosities generally between 200 to 400 cps. he goes be possible in particular to develop water-based varnishes with a viscosity of around 600 cps.

In addition, the capabilities of the new brush allow you to apply the varnish without having to shake the bottle containing this varnish beforehand.

Currently, when applying nail polish, it is desirable to shake the bottle before use so as to modify the thixotropic. Indeed, a classic nail polish in resting state is generally too viscous (eg viscosity 2000 cps) for good application with conventional brushes; after shaking, the viscosity of classic nail polish is in a range about 300 to 400 cps, acceptable with conventional brushes.

A brush according to the invention can accept viscosity (approximately 2000 cps) of a conventional varnish in the idle state, so that it is not no need to shake the vial of varnish before use.

Claims (20)

1. Brush for the application, to the nails, of a nail varnish, or of a similar product, which includes bristles forming a tuft (2) which are fixed at the end of a rod (5) by engagement of the bristle tuft in a housing (9) opening at the end of the rod (5), the bristles having cross-sections admitting a circumscribed circle (C) of constant diameter, characterized in that the region of the opening of the housing (9) situated at the end of the rod (5) has a larger cross-section than the region of the bottom of the said housing (9), so that the tuft (2) of the brush is open to the air and spread out and has relatively large spaces (i) between the bristles (3, 4), this being favourable for good capillary action for products that need to be applied whose viscosity may vary over a wide range.
2. Brush according to Claim 1, characterized in that the region of the bottom of the housing (9) includes a cylindrical portion.
3. Brush according to one of Claims 1 and 2, characterized in that the region of the opening of the housing (9) includes a cylindrical portion.
4. Brush according to Claims 2 and 3 taken simultaneously, characterized in that the housing (9) comprises two cylindrical portions connected by a shoulder.
5. Brush according to Claim 2, characterized in that the housing (9) has the shape of a funnel, the region of the opening (9b) of the said housing (9) having a conical flared shape and being connected to the bottom region (9a) by its small base, the said bottom region (9a) being cylindrical.
6. Brush according to Claim 1, characterized in that the housing has the shape of a cone frustum or pyramid frustum.
7. Brush according to one of Claims 1 to 4, characterized in that the cross-section of the region of the opening of the housing (9) has a shape taken from the group of the following shapes: round, square, rectangular, triangular, oval, cruciform.
8. Brush according to one of Claims 1 to 7, characterized in that the bristles are identical.
9. Brush according to one of Claims 1 to 7, characterized in that at least part of the bristles is made of bristles of natural material.
10. Brush according to Claim 9, characterized in that the natural material is chosen from natural silks, in particular of animal origin.
11. Brush according to one of Claims 1 to 7, 9 or 10, characterized in that at least part of the bristles is made of bristles of a synthetic material chosen from the group formed by polyamides, polyesters, polyether-block-amides, polyethylenes, polytetrafluoroethylenes, polyvinylidene fluorides, polyacetals, polyethylene terephthalates.
12. Brush according to one of Claims 1 to 11, characterized in that the tuft (2) of bristles is made from a bundle (7) of bristles folded in two, the folded part (8) of the tuft (2) being held in the bottom region of the housing (9)
13. Brush according to Claim 12, characterized in that the folded region (8) of the bristles (3, 4) is held in place by a staple (10) forcibly pushed into the housing (9) of the rod (5).
14. Brush according to one of Claims 1 to 13, characterized in that the length (L) by which the bristles of the brush project beyond the end of the rod (5) is between 12 and 30 mm, limits inclusive.
15. Brush according to Claim 11, characterized in that the shape of the cross-section of a bristle of synthetic material is chosen from the following shapes: solid circular, hollow circular, horseshoe-shaped, V-shaped, flat, cruciform, or one equipped with capillary grooves.
16. Brush according to Claim 15, characterized in that the diameter of the circle (C) circumscribing the cross-section of a bristle is between 3/100 mm and 18/100 mm, limits inclusive.
17. Brush according to one of Claims 1 to 16, characterized in that additives modifying the surface finish and surface tension are incorporated into the material of the bristles.
18. Brush according to one of Claims 9 to 11, characterized in that the bristles have a diameter chosen from 11/100 to 40/100 mm.
19. Brush according to Claim 11, characterized in that the bristles are hollowed.
20. Use of a brush according to one of Claims 1 to 19, for the application, to the nails, of a nail varnish or of a similar product.

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