US20230097441A1

US20230097441A1 - Method for lash lengthening

Info

Publication number: US20230097441A1
Application number: US17/488,556
Authority: US
Inventors: Yingchao Chen; Kyoo Jin Park; William Bickford; Chunhua Li; Aline Aude GUIMONT
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2021-09-29
Filing date: 2021-09-29
Publication date: 2023-03-30

Abstract

A method for lengthening lashes is provided, along with a kit for accomplishing the method. The method comprises (i) applying a glue onto an eyelash, (ii) allowing the glue to dry for a period of time; and then (iii) depositing a separate individual fiber onto a distal portion of the eyelash using a microbristle brush applicator having a bristle density above 4 bristles/mm², where each fiber has a diameter greater than 30 microns and a length of 4 mm or less and each fiber is held electrostatically by the microbristle brush applicator. Mascara can then be applied to some or all of the lash and attached fiber.

Description

TECHNICAL FIELD

The present invention relates to cosmetic treatment methods for adding fibers to natural eyelashes and corresponding assemblies.

BACKGROUND

Eyelash extensions and false eyelashes are used for enhancing the length, thickness and fullness of natural eyelashes.
Several methods of applying eyelash extensions may be carried out. The primary method is individually adhering the fibers forming the extensions to the lash line one-by-one, thereby preventing the fibers from sticking to one another. Eyelash extensions may remain on for approximately three to four weeks.
The application of eyelash extensions generally requires a professional, is quite expensive, and takes usually one to two hours. When not applied by a professional, application of eyelash extensions typically requires using complicated tools for handling the eyelash extensions.
For non-professional applications, some products contain a mascara tube and a free fiber tube. For most of such products, there are three application steps: (i) applying a mascara coat on the lashes, (ii) quickly applying a free fiber onto the tip of the lashes before the mascara dries completely, and then (iii) then apply the mascara again for the final look. There are two drawbacks with such products. First, they tend to have thin, fluffy, and white free fibers (specifically, very thin fibers with diameters less than 30 μm, which fly easily and fall near consumers' eye area when applying). And second, the fluffy fibers tend to be easily brushed out when the mascara was applied on afterward.
A technique that avoids these drawbacks is therefore useful and desirable.

BRIEF SUMMARY

In the disclosed method, those drawbacks were resolved by, inter alia, applying new, thicker fibers electrostatically with a microbristle brush with specific characteristics, and using glue as a first step to secure the fiber when later brushed with mascara as the final step. No current or previously available products utilize a glue and individual fibers applied using a microbristle brush for eye makeup product.
Disclosed is an inexpensive, simple method for lengthening lashes via the application of eyelash extensions. The method generally involves three steps: (i) applying a water- or oil-based glue onto a distal portion of an eyelash using a first applicator; (ii) allowing the water- or oil-based glue to dry for a period of time (such as less than 10 seconds); and (iii) depositing one or more separate individual fibers onto the distal portion of the eyelash using a second applicator. Critically, the second applicator should be a microbristle brush applicator having a bristle density above 4 bristles/mm², each separate individual fiber should be held only electrostatically by the microbristle brush applicator, and the separate individual fiber should have a diameter greater than 30 microns and a length of 4 mm or less.
Once the individual fibers have been deposited onto the eyelashes, mascara may optionally then be applied over the eyelashes and the individual fibers, using another applicator configured for applying mascara.
The water- or oil-based glue may have certain advantageous compositions. In some embodiments, the water- or oil-based glue comprise a plurality of solvents present in a total amount between 40% and 60% by weight. The water- or oil-based glue may optionally comprise, or further comprise, a plurality of copolymers, the plurality of copolymers being present in a total amount of between 40% and 50% by weight of the composition, where each of the plurality of copolymers comprises: (i) a monomer of acrylic acid, methacrylic acid, or one of their simple esters, (ii) a hydrogenated styrene monomer; or (iii) a combination thereof. The water- or oil-based glue may optionally comprise, or further comprise, less than 3% by weight of a thickening agent.
Advantageously, each separate individual fiber comprises a synthetic fiber, such as rayon or a nylon (e.g., Nylon 6).
Also disclosed is a kit for achieving the disclosed method. The kit comprises, consists essentially of, or consists of: (i) a first composition comprising a water- or oil-based glue; (ii) a first applicator configured to apply the first composition to an eyelash; (iii) a plurality of separate individual fibers, each having a diameter greater than 30 microns and a length of 4 mm or less; (iv) a second applicator (a microbristle brush applicator) configured to deposit the separate individual fiber onto the eyelash electrostatically, the microbristle brush applicator having a bristle density above 4 bristles/mm2; (v) optionally a second container configured to contain the plurality of separate individual fibers, preferably the second container having walls defining a single opening, the second applicator being configured to cover the single opening; and (vi) optional instructions for use. Optionally, the first applicator is formed as part of a cap on a first container, where the first container (which may be, e.g., a glass or plastic bottle) defines an internal volume with a single opening covered by the cap, the internal volume containing the first composition. Preferably, the first container is waterproof.
In some embodiments, the kit may optionally contain a second composition comprising a mascara, and a third applicator configured to apply the second composition over at least a part of the combined eyelash and separate individual fiber after the separate individual fiber has been deposited onto an eyelash. Optionally, the third applicator is formed as part of a cap on a third container, where the third container (which may be, e.g., a glass or plastic bottle) defines an internal volume with a single opening covered by the cap, the internal volume containing the second composition.

BRIEF DESCRIPTION OF DRAWINGS

The invention may be better understood from reading the following detailed description of non-limiting exemplary embodiments thereof and from examining the figures, in which:

FIG. 1 is a block-diagram illustrating the successive steps of the method according to the invention,

FIG. 2 is a perspective view of a microbristle brush applicator,

FIG. 3 is a schematic representation of using a microbristle brush applicator to deposit a fiber on an eyelash, and

FIG. 4 represents schematically an example of a cosmetic assembly (“kit”) according to the invention.

FIG. 5 represents schematically an example of a container used to hold individual fibers, where a microbristle brush is used to close or cover the opening to the container.

DETAILED DESCRIPTION

As used herein, the term “free [of an ingredient]” means that the identified ingredient is only present in an amount below its detectable limit, and preferably that the composition contains 0% of the identified ingredient.
As used herein, the term “substantially free [of an ingredient]” means that the composition contains less than 1% of the identified ingredient.
Embodiments of the disclosed method can best be described with reference to FIG. 1 .
As seen in FIG. 1 , embodiments of the disclosed method 10 will generally comprise a sequence of steps.
The first step 20 involves applying a water- or oil-based glue (sometimes referred to herein as an adhesive) to a distal portion of one or more eyelashes. Referring briefly to FIG. 3 , an eyelash 80 extends outward from the eyelid 82, away from the eye, towards a distal portion 81.
A “water-based glue” as used herein, refers to a glue that contains at least 1% water. Generally, such compositions will contain multiple ingredients that are water-soluble. An “oil-based glue” as used herein, refers to a glue that contains less than 1% water. Preferably, the oil-based glues are free of water and silicones.
The glues used in the disclosed method are not mascaras. The glues used in some embodiments of the disclosed method are preferably substantially free, or free, of waxes. The glues used in some embodiments of the disclosed method are preferably substantially free, or free, of pigments and/or colorants. The glues used in some embodiments of the disclosed method are more preferably substantially free, or free, of waxes, pigments, and/or colorants.
The glues used in the disclosed method will have a high tack. “Tack” as used herein refers to the quality exhibited by compositions that adhere to an object after application to a substrate. Tack may be evaluated by any method known in the art for evaluating it, such as using a texture analyzer. For example, a sample can be applied to a substrate (for example, a 1 mil drawdown), allowed to dry (for example, for 1 minute), and contacted by an object such as a rubber conical probe (18.3 mm at the tip, 29 mm in height, and 25.4 mm at the base), after which the force associated with removal of the probe from the object can be measured and reported as tack (g). Such measurements can be performed less than 5 minutes after the drying period, such as between 3 and 3.5 minutes. Preferably, glues of the present invention possess tack properties, when determined by this method, of greater than 45 g, preferably greater than 50 g, preferably greater than 70 g, preferably greater than 90 g, and preferably greater than 100 g. So, glues of the present invention preferably have tack properties ranging from about 30 g to about 200 g, preferably from about 50 g to about 150 g, and preferably from about 70 g to about 130 g, including all ranges and subranges therebetween such as, for example, about 45 g to about 110 g, about 50 g to about 110 g, about 70 g to about 120 g, about 90 g to about 115 g, etc.
In some embodiments, the water- or oil-based glue may for example be chosen among the adhesive composition for eyelashes called DUO® eyelash adhesive, commercialized by American International Industries, or the one called Daitosol 5500GM, an acrylates/ethylhexyl acrylate copolymer commercialized by DAITO KASEI KOGYO.
Other water- or oil-based glues may be used. For example, in various embodiments, the water- or oil-based glue may comprise:
(A) a plurality of solvents in a total amount that is between 40% and 60% by weight of the composition. In some embodiments, the water- or oil-based glue may comprise ethanol in a total amount of between 3% and 8% by weight of the composition. In some embodiments, the water- or oil-based glue may comprise water, ethanol, or both, in a total amount of between 40% and 60% by weight of the composition.
(B) a plurality of copolymers, the plurality of copolymers being present in an amount of between 40% and 50% by weight of the composition, where each of the plurality of copolymers comprises: (i) a monomer of acrylic acid, methacrylic acid, or one of their simple esters, (ii) a hydrogenated styrene monomer; or (iii) a combination thereof.
(C) less than 3% by weight of a thickening agent.
In some embodiments, the water- or oil-based glue may comprise (A) and (B). In some embodiments, the water- or oil-based glue may comprise (A) and (C). In some embodiments, the water- or oil-based glue may comprise (A), (B), and (C).
The second step of the method 10 involves waiting 30 for at least a short period of time to allow the water- or oil-based glue to start drying. The time is generally based on the solvent system utilized, and the time t should be less than time it takes the glue requires to completely dry on the eyelash. Such time t may be t≤30 seconds, t≤25 seconds, t≤20 seconds, t≤15 seconds, t≤10 seconds, or t≤5 seconds. In some embodiments, t is at least 3 seconds. For example, 3 seconds>t>30 seconds, 3 seconds≤t≤20 seconds, or 3 seconds≤t≤10 seconds.
The third step of the method 10 comprises adhering at least one fiber (optionally, only one fiber) electrostatically onto a second applicator 40. This can generally be accomplished by bringing the applicator into contact with the fiber(s). The microbristle brush applicator and fibers will be discussed separately below. In some embodiments, one fiber is adhered electrostatically before proceeding to the next step in the method. In some embodiments, a plurality of fibers is adhered electrostatically before proceeding to the next step in the method.
Preferably, the fibers are in a plastic container having a single opening. Pulling the microbristle brush out of the container, one or more fibers are electrostatically attracted to the microbristle brush bristles. In some embodiments, the microbristle brush may be twisted while pulling the brush out of the container in order to attract more fibers.
Microbristle Brush Applicator
The second applicator is a microbristle brush applicator having a bristle density above 4 bristles/mm². Microbristle brush applicators are known generally in the art. For example, U.S. Pat. Nos. 8,201,566 and 10,681,973 describe examples of microbristle brush applicators.
An example of such an applicator can be seen with reference to FIG. 2 . As seen in FIG. 2 , a microbristle brush applicator 70 that comprises a handle portion 75 at a proximal end 73 of the applicator, and a bristle portion 76 at a distal end 74 of the applicator. The bristle portion 76 generally extends a distance L longitudinally from the handle portion 75 towards the distal end 74.
The bristle portion 76 comprises one or more high density zones 77. Each high-density zone 77 comprises a plurality of bristles 78 that protrude radially outward from the core 72. The length L of the core may vary between embodiments, but generally is about 10 mm to about 50 mm. The core may be formed from a variety of materials, including plastics, and in some embodiments the core may be non-metallic. The core may have any cross-sectional shape, such as circular, octagonal, freeform, etc.
Each high-density zone extends longitudinally. The bristles conform to certain bristle density criteria that enable efficient transfer of individual fibers to eyelashes. The brush may include a single high-density zone or a plurality of high-density zones. In some embodiments, one or more high density zones may substantially make up the entire brush. For example, the brush 70 of FIG. 2 includes a single high-density zone 77 that has a length equal to the length L of the bristle portion 76.
Each bristle may generally be formed from any thermoplastic material that is optionally relatively rigid, e.g.: styrene-ethylene-butylene-styrene (SEBS); a silicone rubber; latex rubber; a material having good slip; butyl rubber; ethylene-propylene terpolymer rubber (EPDM); a nitrile rubber; a thermoplastic elastomer; a polyester, polyamide polyethylene, or vinyl elastomer; a polyolefin such as polyethylene (PE) or polypropylene (PP); polyvinyl chloride (PVC); ethyl vinyl acetate (EVA); polystyrene (PS); SEBS; styrene-isoprene-styrene (SIS); polyethylene terephthalate (PET); polyoxymethylene (POM): polyurethane (PU); styrene acrylonitrile (SAN); polyamide (PA); or polymethyl methacrylate (PMMA). It is also possible to use a ceramic. e.g., an alumina-based ceramic, a resin, e.g., a urea formaldehyde type resin, possibly a material filled with graphite. In particular, it is possible to use materials known under the trade names Teflon, Hytrel®, Cariflex®, Santoprene®, Pebax®, Pollobas®, this list not being limiting. Preferably, each bristle is formed from at least one thermoplastic elastomer.
The dimensions of individual bristles may vary between embodiments. In particular, the bristle length and bristle diameter can greatly influence brush performance. As used herein, bristle length is measured as the exposed length of a bristle that projects radially outwardly beyond the outer surface of the core—not the length considering any additional bristle length below the outer surface of the core. It has been discovered that in high density zones, bristle lengths of about 1 mm to about 3 mm are preferred for applying formulations to fine hairs, for example bristle lengths of about 1 mm, about 1.25 mm, about 1.5 mm, about 2.0 mm, about 2.5 mm, and/or about 3 mm.
Bristle diameter is evaluated along the distance between an outer end of the bristle and the end of bristle near the base and in vicinity of the core surface. The bristle diameter should be determined at the position closest to the base, after any rounds or chamfers at the base of the bristle at or near the core surface. Bristle diameter is the largest cross-sectional distance (width, diameter, etc. as appropriate for the cross-sectional geometry of the bristle) in the portion of the bristle just above the base and any rounding, chamfering, etc. near the base. Bristle diameter may be about 0.15 mm to about 0.35 mm, e.g., about 0.15 mm, about 0.175 mm, about 0.2 mm, about 0.25 mm, about 0.3 mm, and about 0.35 mm.
Bristle density is a key variable in high density zones configured to electrostatically transfer fibers to an eyelash. A key measure of bristle density is the number of bristles relative to the core surface area. It has been discovered that in order to effectively transfer fibers electrostatically to an eyelash, a high-density zone should have a bristle density at least 4 whole bristles per square millimeter of surface area of the core (i.e., the nominal core surface area, not considering the surface area occupied by the bristles themselves). In some embodiments, the bristle density d_Bis d_B≥4 bristles/mm², d_B≥5 bristles/mm², d_B≥6 bristles/mm².
Fibers
Each separate individual fiber for use in the disclosed method should have a nominal outer diameter D that is at least 30 microns, although D is preferably greater than 30 microns. In some embodiments, D≥30 μm, D>30 μm, D>35 μm, and D>40 μm.
Each separate individual fiber for use in the disclosed method should have a total length L_Fof 4 mm or less. In some embodiments, L_F≤4 mm, L_F≤3.5 mm, or L_F≤3 mm, and L_F≥1 mm, L_F≥1.5 mm, L_F≥2 mm, or any combination thereof. For example, in some embodiments, 2 mm≤L_F≤3.5 mm, or 1 mm≤L_F≤4 mm.
Each separate individual fiber preferably comprises a synthetic fiber, such as rayon or a nylon (e.g., Nylon 6).
Referring back to FIG. 1 , once the applicator has electrostatically adhered a fiber, the fourth step of the method 10 is to deposit the fiber 50 onto a distal portion of the eyelashes.
A simplified schematic of this can be seen in FIG. 3 . There, a fiber 90 is electrostatically adhered to a microbristle brush applicator 70 (and specifically to the bristles 78 extending from the core 72 of the applicator). Preferably, a first end 91 of the fiber 90 is closer to the core 72 of the microbristle brush applicator 70 than a second end 92. Preferably, a first end 91 of the fiber 90 is within and among the bristles of the microfiber; that is, a first end 91 is within a volume of space defined by the outermost edges of each bristle 78 of the microbristle brush application 70. More preferably, no more than 40% of the entire length of the fiber is within that volume of space (said differently, 60% of the entire length of the fiber is further from the core than an outermost end of a bristle the fiber is in contact with. The second end 92 of the fiber preferably extends outwards in a direction that is substantially away from the core 72, to place the second end 72 in a position to more easily come into contact with a distal portion of the eyelashes.
The applicator 70 is raised so that fiber 90 is brought into contact with the distal portion 81 of the eyelash 80, which has the drying adhesive composition on it. At this time, the applicator 70 can then be moved away from the face and used to apply additional fibers if desired. Preferably, an end portion (e.g., some portion of the fiber no more than 25% of the length of the fiber away from either of the two ends) of each fiber is adhered to the distal portion (e.g., some portion of the eyelash no more than 25% of the length of the eyelash away from the most distal end) of the eyelash, such that the majority, and preferably all, of each fiber extends beyond the distal portion of the eyelash the fiber is attached to.
Referring again to FIG. 1 , it can be seen that the method 10 may involve multiple iterations of adhering fiber(s) to the brush and depositing them on the eyelash. However, once the desired fibers have been deposited, the method 10 may optionally include applying mascara 60 over the deposited fibers.
Mascara compositions are well-known in the art; such compositions may be water-based or anhydrous, and will generally comprises pigments or other colorants, as well as film formers, thickeners, solvents, and/or other additives. Any appropriate mascara may be utilized here.
A disclosed method may be implemented with the aid of an assembly 100 (also called “kit”) according to the invention, shown in FIG. 4 .
The assembly 100 will generally comprise, consist essentially of, or consist of several components.
First, the assembly will contain a first composition, a water- or oil-based glue 110 as described previously, which is preferably contained within an internal cavity of a first container 125. The container is preferably comprised of glass or a polymer.
Assembly 100 also comprises a first applicator 120 that is configured to allow a user to apply the water- or oil-based glue onto the distal portion of eyelashes. Such applicators are known to those of skill in the art. In FIG. 4 , the first applicator 120 is shown as a small bristle (e.g., similar to a mascara brush).
First container 125 may comprise a threaded neck 126 and a cap 121 for closing the container by cooperating with the threaded neck 126. Optionally, the first applicator is formed as part of a cap on a first container 125. In some embodiments, the cap 121 is attached to the first applicator 120. The first applicator 120 may comprise a shaft portion 122 (which may be directly or indirectly attached to the cap 121) and an application element 123 at a free end. A wiping element, in this example, may be on the interior side of the neck 126. The application element 123 is preferably loaded with the adhesive composition 110 in the container 125 before passing through the wiping element for being used in the first step of the method.
Assembly 100 also comprises a second applicator 140. The second applicator is a microbristle brush applicator as described previously, with a handle portion 141 and a bristle portion 142.
Assembly 100 also comprises a plurality of fibers 130, which may be contained within a separate second container 135 (such as a bag, small box, etc. configured to contain the fibers and make them readily accessible for a user).
Each fiber 131 of the plurality of fibers 130 should have a nominal outer diameter D that is at least 30 microns, although D is preferably greater than 30 microns. In some embodiments, D≥30 μm, D>30 μm, D>35 μm, and D>40 μm.
Each fiber 131 of the plurality of fibers 130 should have a total length L_Fof 4 mm or less. In some embodiments, L_F≤4 mm, L_F≤3.5 mm, or L_F≤3 mm, and L_F≥1 mm, L_F≥1.5 mm, L_F≥2 mm, or any combination thereof. For example, in some embodiments, 2 mm≤L_F≤3.5 mm, or 1 mm≤L_F≤4 mm.
Each fiber 131 of the plurality of fibers 130 may preferably comprise a synthetic fiber, such as rayon or a nylon (e.g., Nylon 6).
The plurality of fibers 130 will include fibers having one or more colors. In some embodiments, each fiber 131 may be the same color, or may be a color different from one or more other fibers. For example, in some embodiments, a portion of the fibers are one color, and a portion of the fibers are a second color.
As seen in FIG. 5 , in some preferred embodiments the second container 135 is a container with an outer surface 136 and an inner surface 138, the inner surface defining an internal volume of space within the container having a single opening 137 at one end of the container. The container is generally comprised of a polymer, although other materials may be used. The container may be opaque, translucent, or transparent. The individual fibers 130 can be within the internal volume of the container and are generally loose and randomly deposited within the internal volume. The microbristle brush 140 can be inserted at least partially into the internal volume of the container 135. Preferably, only some or all of the bristle portion 142 is inserted into the internal volume of the container. Microbristle brush 140 preferably has a handle portion 141 that includes a cap portion 143. Cap portion 143 preferably is configured to interact with the end of the container 135 that has the single opening in order to close the container. This can be done via threading the cap onto a threaded portion (not shown) of the container 135, having the cap portion be press fit over or into the open end of the container, or some other known technique for connecting the two sub-components.
Assembly 100 may optionally comprise a second composition 150, a mascara composition, which is preferably contained within an internal cavity of a third container 165. The container is preferably comprised of glass or a polymer.
Assembly 100 also comprises a third applicator 160 that is configured to allow a user to apply the mascara 150. Such applicators are known to those of skill in the art. In FIG. 4 , the third applicator 160 is shown as a third type of brush applicator.
Third container 165 may comprise a threaded neck 166 and a cap 161 for closing the container by cooperating with the threaded neck 166. Optionally, the third applicator is formed as part of a cap on a third container 165. In some embodiments, the cap 161 is attached to the third applicator 160. Like the first applicator, the third applicator 160 may comprise a shaft portion and an application element at a free end. A wiping element, in this example, may exist on the interior side of the neck 166. The application element is preferably loaded with the mascara composition 150 in the container 165 before passing through the wiping element for being used in the final step of the method.

EXAMPLES

Below are examples of water- and oil-based glues that may be utilized as part of the disclosed method.
For the oil-based glue, the A1 components are heated and mixed until homogenous, then cooled to room temperature, and the A2 components are added and mixed.

TABLE 1

Example Oil Based Glue (G1)

Phase	INCI name	% w/w

A1	ACRYLATES/ISOBORNYL ACRYLATE	75-85%
	COPOLYMER IN ISODODECANE
	(~50% SOLIDS)
A1	HYDROGENATED STYRENE/ISOPRENE	1-5%
	COPOLYMER
A1	HYDROGENATED STYRENE/BUTADIENE	1-5%
	COPOLYMER
A1	ISODODECANE	10-20%
A2	ALCOHOL DENAT.	4-5%
A2	CAPRYLYL GLYCOL	0-2%

For the water-based glue, the A1 components are added sequentially and mixed until homogenous at room temperature. Then B2 components are added and mixed until homogenous, and the B3 components are added afterward. At last the B4 components are added and mixed until homogenous.

TABLE 2

Example Water-Based Glue (G2)

Phase	INCI name	% w/w

A1	ACRYLATES COPOLYMER IN WATER	40-50%
	(~50% SOLIDS)
A1	ACRYLATES/ETHYLHEXYL ACRYLATE	40-50%
	COPOLYMER IN WATER (~55% SOLIDS)
B2	PENTYLENE GLYCOL	1-5%
B2	PHENOXYETHANOL	0-1%
B2	HYDROXYETHYLCELLULOSE	0-1%
B2	CARRAGEENAN	0-1%
B2	DIISOPROPYL ADIPATE	0-1%
B3	WATER	4-5%
B4	ALCOHOL DENAT.	0-1%
B4	FRAGRANCE	0-1%

Using G1 and G2, various fibers were applied to eyelashes, generally using the described technique, but allowing the fiber configurations to vary. The results were then assessed after application of mascara for subjective lash lengthening. The table below summarizes the results.

TABLE 3

Summary of Results Using Different Fiber Characteristics

Fiber
Composition	Fiber Diameter	Fiber Length	Results Using	Results Using
(INCI Names)	(μm)	(mm)	G1	G2

1 - Nylon-6 (and)	30	4	Lash	Minor Lash
Silica (and)			Lengthening	Lengthening
Black 2
2 - Rayon	20	1.3	Fibers Brushed	Fibers Brushed
			Out	Out
3 - Rayon (and)	43	3	Lash	Lash
Silica (and)			Lengthening	Lengthening
Black 2
4 - Rayon (and)	17	3.2	Minor Lash	Fibers Brushed
Water (and)			Lengthening	Out
Black 2
5 - Rayon (and)	27	3.2	Fibers Brushed	Fibers Brushed
Water			Out	Out
6 - Rayon (and)	27	5.1	Minor Lash	Fibers Brushed
Water			Lengthening	Out

As is seen, using G1 and G2, only fibers with diameters greater than about 30 μm and fiber lengths less than 4 mm were seen to exhibit lash lengthening (Fiber compositions 1 and 3). 6 out of the 10 tested combinations resulted in fibers being brushed out, indicating the fibers were not attaching properly to the eyelash.
Using Rayon #3 from Table 3, the method was repeated using different combinations of second applicators—that is, 4 different configurations of bristles (high density refers to >4 bristles/mm², low density refers to <4 bristles/mm²) to electrostatically apply the fibers to the lash. The subject lash-lengthening results, after application of mascara, are summarized below.

TABLE 4

Summary of Results Using Different Second Applicators

Applicators	Results

Brush 1 - High Density Bristles	Lash Lengthening
Brush 2 - Low Density Elastomeric Bristles	No Lengthening
Brush 3 - Low Density Rigid Bristles	No Lengthening
Brush 4 - High Density Bristles - Alternate	Lash Lengthening
Configuration

If various fibers were applied to eyelashes, generally using the described technique, but allowing the fiber configurations to vary. The results were then assessed after application of mascara for subjective lash lengthening. The table below summarizes the results.
Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

Claims

What is claimed is:

1. A method for lengthening lashes, comprising:

applying a water- or oil-based glue onto a distal portion of an eyelash using a first applicator;

allowing the water- or oil-based glue to dry for a period of time; and

depositing a separate individual fiber onto the distal portion of the eyelash using a second applicator, the second applicator being a microbristle brush applicator having a bristle density above 4 bristles/mm², the separate individual fiber being held electrostatically by the microbristle brush applicator, and the separate individual fiber has a diameter greater than 30 microns.

2. The method according to claim 1, wherein the separate individual has a length of 4 mm or less.

3. The method according to claim 1, further comprising applying a mascara over the deposited separate individual fiber.

4. The method according to claim 1, wherein the water- or oil-based glue comprises a plurality of solvents in a total amount of between 40% and 60% by weight of the composition.

5. The method according to claim 4, wherein the water- or oil-based glue further comprises a plurality of copolymers, the plurality of copolymers being present in a total amount of between 40% and 50% by weight of the composition, each of the plurality of copolymers comprising: (i) a monomer of acrylic acid, methacrylic acid, or one of their simple esters, (ii) a hydrogenated styrene monomer; or (iii) a combination thereof

6. The method according to claim 5, wherein the water- or oil-based glue further comprises less than 1% by weight of a thickening agent.

7. The method according to claim 1, wherein the separate individual fiber comprises a synthetic fiber.

8. The method according to claim 7, wherein the synthetic fiber comprises rayon or a nylon.

9. The method according to claim 1, wherein the period of time is less than 10 seconds.

10. The method according to claim 1, wherein a bristle diameter of each bristle of the microbristle brush is between 0.15 mm and 0.35 mm.

11. The method according to claim 1, wherein a length of each bristle of the microbristle brush is between 1 mm and 3 mm.

12. The kit, comprising:

a first composition comprising a water- or oil-based glue;

a first applicator configured to apply the first composition to an eyelash;

a plurality of separate individual fibers, each having a diameter greater than 30 microns and a length of 4 mm or less;

a second applicator configured to deposit the separate individual fiber onto the eyelash electrostatically, the second applicator being a microbristle brush applicator having a bristle density above 4 bristles/mm²; and

optional instructions for use.

13. The kit according to claim 12, wherein the first applicator is formed as part of a cap on a first container, the first container containing the first composition.

14. The kit according to claim 12, wherein the second applicator is formed as part of a cap on a second container, the second container containing the plurality of separate fibers.

15. The kit according to claim 12, further comprising:

a second composition comprising a mascara; and

a third applicator configured to apply the second composition over the separate individual fiber after the separate individual fiber has been deposited onto an eyelash.

16. The kit according to claim 15, wherein the third applicator is formed as part of a cap on a third container, the third container containing the second composition.

17. The kit according to claim 12, wherein a bristle diameter of each bristle is between 0.15 mm and 0.35 mm and a length of each bristle is between 1 mm and 3 mm.