Nail sticker having three-dimensional curved shape

Abstract

A nail sticker having a three-dimensional curved shape is disclosed. The nail sticker having a three-dimensional curved shape according to the present invention comprises: a sticker body having a lower surface to be adhered to a nail, the sticker body being flexible and having a three-dimensional curved shape corresponding to the shape of a nail; and a semi-cured layer provided on an upper surface of the sticker body. The nail sticker is flexible and has a three-dimensional curved surface corresponding to the shape of a nail, such that the nail sticker exhibits a predetermined bending strength before the semi-cured layer is cured.

Description

Nail sticker with a three-dimensional curved shape

[0001] The present invention relates to a nail sticker having a three-dimensional curved shape.

[0002] Generally, artificial nails or nail stickers that complement manicures are mainly used as methods to decorate fingernails.

[0003] Artificial nails have the advantage of superior aesthetics compared to natural nails and the ability to be molded to extend from the nails, but they present problems such as a foreign body sensation for the wearer, hair getting caught between the nail and the artificial nail, and contaminants seeping in.

[0004] On the other hand, nail stickers have the advantage of excellent fit and prevent hair from getting caught or contaminants from seeping in between the nail and the sticker, but they have the problem of being difficult to extend outward from the original nail.

[0005] In addition, considering that artificial nails require advanced technical skills for production and use, and consume a significant amount of time and money, nail stickers printed with various patterns and colors are gaining popularity.

[0006] Accordingly, there is an increasing need for nail stickers that offer excellent fit and can be extended outward from the fingernails.

[0007] [Prior Art Literature]

[0008] [Patent Literature]

[0009] Republic of Korea Registered Patent No. 10-1797203 (Published Nov. 15, 2017)

[0010] Therefore, the technical problem that the present invention aims to solve is to provide a nail sticker having a three-dimensional curved shape that can further improve the fit and also extend outward from the fingernail, etc.

[0011] According to one aspect of the present invention, a nail sticker is provided having a sticker body having a three-dimensional curved shape corresponding to the shape of a nail, having a lower surface that is adhered to a nail and has flexibility, and a semi-cured layer provided on the upper surface of the sticker body, wherein the nail sticker has flexibility and has a three-dimensional curved shape corresponding to the shape of a nail so as to have a predetermined bending strength before the semi-cured layer is cured.

[0012] The above semi-cured layer can have a uniform thickness in the direction of the free edge from the cuticle layer of the nail.

[0013] The thickness of the one end adjacent to the cuticle layer of the nail and the other end adjacent to the free edge of the semi-cured layer may be reduced compared to the thickness of the center.

[0014] The above semi-cured layer may have a three-dimensional shape in which the thickness increases from the cuticle layer of the nail toward the free edge.

[0015] The ratio of the thickness of one end of the nail sticker adjacent to the cuticle layer of the nail to the thickness of the other end of the nail sticker adjacent to the free edge of the nail may be 1.5 to 13.

[0016] When the upper surface of the center of the nail sticker is pressed with a load of 0.15 to 4.0 N while the above semi-cured layer is in a state before curing, it can have flexibility such that it deforms and the lower surface of the center of the nail sticker becomes flat.

[0017] When the upper surface of the center of the nail sticker is pressed with a load of 11.0 N or more while the above semi-cured layer is cured, it can have flexibility such that it deforms and the lower surface of the center of the nail sticker becomes flat.

[0018] The above nail sticker can be extended to protrude outward from the free edge of the nail.

[0019] The above-mentioned semi-cured layer contains a photocuring component, and the semi-cured layer can be photocured after the nail sticker is adhered to the fingernail.

[0020] The nail sticker according to an embodiment of the present invention has a three-dimensional curved surface corresponding to the shape of a fingernail, so when it is adhered to a fingernail or the like, it can have an improved fit compared to conventional ones.

[0021] In addition, since the nail sticker according to the embodiment of the present invention has a three-dimensional curved surface, a predetermined bending strength can be imparted to the nail sticker, thereby improving resistance to bending, curvature, etc. of the nail sticker, and can also be extended outwardly to the fingernail, etc.

[0022] In addition, the nail sticker according to the embodiment of the present invention can prevent bending, breaking, or cracking during use by curing the semi-cured layer after being adhered to the fingernail, etc.

[0023] FIG. 1 is a perspective view showing a nail sticker having a three-dimensional curved shape according to the present invention.

[0024] FIG. 2 is a cross-sectional view of AA of FIG. 1, showing one embodiment of a semi-cured layer.

[0025] FIG. 3 is a cross-sectional view of AA of FIG. 1, showing another embodiment of the semi-cured layer.

[0026] FIG. 4 is a cross-sectional view of AA of FIG. 1, showing another embodiment of the semi-cured layer.

[0027] FIG. 5 is a cross-sectional view of the BB of FIG. 1, showing one embodiment of a semi-cured layer.

[0028] FIG. 6 is a cross-sectional view of the BB of FIG. 1, showing another embodiment of the semi-cured layer.

[0029] FIG. 7 is a drawing showing a flexibility test of a nail sticker according to the present invention.

[0030] FIGS. 8 and 9 are usage diagrams of a nail sticker having a three-dimensional curved shape according to the present invention.

[0031] FIG. 10 is a drawing showing a state in which a box sticker is transferred to the lower surface of a nail sticker while the nail sticker having a three-dimensional curved shape according to the present invention is attached to a fingernail.

[0032] FIG. 11 is a perspective view showing a state in which a nail sticker having a three-dimensional curved shape according to the present invention is adhered to a fingernail.

[0033] In order to fully understand the present invention, the operational advantages of the present invention, and the objectives achieved by the implementation of the present invention, reference must be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described therein.

[0034] The present invention will be described in detail below by explaining preferred embodiments of the invention with reference to the attached drawings. Identical reference numerals in each drawing indicate identical components.

[0035] FIG. 1 is a perspective view showing a nail sticker having a three-dimensional curved shape according to the present invention; FIG. 2 is a cross-sectional view AA of FIG. 1 showing one embodiment of a semi-cured layer; FIG. 3 is a cross-sectional view AA of FIG. 1 showing another embodiment of a semi-cured layer; FIG. 4 is a cross-sectional view AA of FIG. 1 showing yet another embodiment of a semi-cured layer; FIG. 5 is a cross-sectional view BB of FIG. 1 showing one embodiment of a semi-cured layer; FIG. 6 is a cross-sectional view BB of FIG. 1 showing another embodiment of a semi-cured layer; and FIG. 7 is a drawing showing a flexibility test of a nail sticker according to the present invention.

[0036] Referring to FIGS. 1 to 7, the nail sticker (100) according to the present invention has a three-dimensional curved shape corresponding to the shape of a fingernail (M), so when it is adhered to a fingernail (M), it can have a better fit than a conventional nail sticker. In addition, the nail sticker (100) according to the present invention is provided with a predetermined bending strength according to the three-dimensional curved shape, so it can be extended outward from the fingernail (M).

[0037] The nail sticker (100) according to the present invention comprises a sticker body (110) that adheres to a fingernail (M) and a semi-cured layer (130) provided on the upper surface of the sticker body (110).

[0038] The sticker body (110) according to the present embodiment has a lower surface that adheres to the user's fingernail (M), etc. The sticker body (110) has flexibility and has a three-dimensional curved shape corresponding to the shape of the fingernail (M).

[0039] The sticker body (110) includes a release liner (not shown), an adhesive layer (111) that is peelably adhered to the upper surface of the release liner, a substrate layer (113) provided on the upper surface of the adhesive layer (111), and a design layer (115) provided between the substrate layer (113) and the semi-cured layer (130). Meanwhile, the design layer (115) according to the present embodiment may be provided between the adhesive layer (111) and the substrate layer (113).

[0040] Additionally, the sticker body (110) according to the present embodiment may further include an intermediate layer (117) provided on the upper part of the design layer (115). When the intermediate layer (117) is added, the design layer (115) may be provided between the substrate layer (113) and the intermediate layer (117).

[0041] The release liner according to the present embodiment prevents the adhesive component of the adhesive layer (111) from becoming fixed.

[0042] As described above, an adhesive layer (111), a base layer (113), a design layer (115), and a semi-cured layer (130) may be sequentially laminated on the upper surface of the release liner. Additionally, an adhesive layer (111), a base layer (113), a design layer (115), an intermediate layer (117), and a semi-cured layer (130) may be sequentially laminated on the upper surface of the release liner. The adhesive layer (111), the base layer (113), the design layer (115), the intermediate layer (117), and / or the semi-cured layer (130) are peeled off from the release liner as a whole.

[0043] Release paper can be manufactured by surface coating silicone, Teflon, fluorine, etc. onto a film or sheet made of any one selected from paper, polyvinyl chloride (PVC), polyethylene (PE), polyurethane (PU), polypropylene (PP), polyethylene phthalate (PET), polyolefin elastomer (POE), ethylene-vinyl acetate copolymer (EVA), and acrylic resins, or a polymer thereof.

[0044] The adhesive layer (111) according to the present embodiment is adhered to a fingernail (M), etc.

[0045] The adhesive layer (111) may be composed of any one of a vinyl monomer-based polymerized adhesive, a rubber-based adhesive, a polyurethane-based two-component adhesive, or a blend of these.

[0046] It is preferable that the adhesive strength of the adhesive layer (111) be 300 to 25,000 gf / in. The adhesive strength can be measured using the ASTM D3330 180-degree PEEL TEST. For example, when the adhesive layer (111) is attached to a fingernail (M), if the adhesive strength of the adhesive layer (111) is less than 300 gf / in, the adhesive layer (111) may lift off the fingernail (M) and be easily separated from the fingernail (M); if the adhesive strength of the adhesive layer (111) exceeds 25,000 gf / in, the fingernail (M) may be damaged when the user separates the adhesive layer (111) from the fingernail (M) for replacement. Therefore, it is preferable that the adhesive strength of the adhesive layer (111) be 300 to 25,000 gf / in.

[0047] In this embodiment, the adhesive layer (111) may be provided at the bottom of the substrate layer (113) or at the bottom of the design layer (115).

[0048] The adhesive layer (111) may be provided on the entire lower surface of the substrate layer (113) or the design layer (115), or on the remaining area excluding the area protruding outward from the free edge of the fingernail (M) in consideration of the length of the fingernail (M).

[0049] When the adhesive layer (111) is provided over the entire lower surface of the substrate layer (113) or the design layer (115), if the adhesive layer (111) is attached to the nail (M), the adhesive layer (111) located in the area protruding outward from the free edge of the nail (M) may become contaminated during use. Therefore, to prevent contamination of the externally exposed adhesive layer (111), a UV top gel or top coat (Dry) may be applied to the exposed adhesive layer (111), or a box sticker (170) may be attached to the exposed adhesive layer (111) and then transferred. When a UV top gel or top coat is applied, the nail sticker (100) is expected to become more durable and usable for a longer period of time, but since there is the inconvenience of the user having to perform additional procedures, it is preferable to attach a box sticker (170) to the exposed adhesive layer (111) to ensure ease of use (see FIG. 11).

[0050] Meanwhile, even if the adhesive layer (111) is provided in a part of the lower surface of the base layer (113) or design layer (115), UV top gel or top coat (Dry) can be applied to the lower surface of the base layer (113) or design layer (115) that is exposed outward from the free edge of the fingernail (M), or a box sticker (170) can be attached to prevent foreign matter from getting stuck between the sticker body (110) and the fingernail (M).

[0051] The substrate layer (113) according to the present embodiment is intended to provide flexibility to the sticker body (110) and improve the strength of the sticker body (110), and can be laminated on top of the adhesive layer (111).

[0052] The substrate layer (113) may be any one selected from polyvinyl chloride (PVC), polyethylene (PE), polyurethane (PU), thermoplastic polyurethane (TPU), polypropylene (PP), polyethylene phthalate (PET), polyolefin elastomer (POE), ethylene-vinyl acetate copolymer (EVA), and acrylic resin, or may be a film or sheet made of a polymer thereof, provided that the materials of the substrate layer (113) listed above are merely examples and the scope of the present invention is not limited by them. Additionally, the substrate layer (113) may further include a filler (not shown), such as glass fiber.

[0053] The design layer (115) according to the present embodiment provides a color or design. The design layer (115) may be arranged to be laminated on the upper part of the substrate layer (113) or on the lower part of the substrate layer (113).

[0054] The design layer (115) may be printed in a single color over the entire upper or lower portion of the substrate layer (113), but is not limited thereto; the entire upper or lower portion of the substrate layer (113) may be divided into multiple areas, and each area may have different colors or a predetermined color printed repeatedly.

[0055] The design layer (115) can be formed on the upper or lower part of the substrate layer (113) by gravure printing, silk printing, flexographic printing, digital printing, laser printing, UV printing, master printing, rotary printing, sealing printing, offset printing, pad printing, screen printing, air brushing using an air gun, spraying method, and flocking method, etc.

[0056] Additionally, the design layer (115) may be a transparent or opaque film or sheet laminated on the upper or lower part of the substrate layer (113). Additionally, the design layer (115) may be a transparent holographic film in which various holographic patterns, designs, etc. are formed on one side of the substrate film. The holographic film changes various colors or patterns depending on the viewing direction. Furthermore, the substrate film used for the transparent holographic film may be manufactured from a polymer resin that is identical or similar to the material of the aforementioned substrate layer (113).

[0057] Meanwhile, in this embodiment, when a design layer (115) is provided on top of the substrate layer (113), an intermediate layer (117) may be additionally provided on top of the design layer (115).

[0058] The intermediate layer (117) according to the present embodiment is intended to provide flexibility to the sticker body (110) and improve the strength of the sticker body (110), and can be laminated on top of the design layer (115).

[0059] Since the intermediate layer (117) can be formed in the same way as the aforementioned substrate layer (113), a detailed description thereof will be omitted.

[0060] The semi-cured layer (130) according to the present embodiment may be provided to be laminated over the entire upper portion of the sticker body (110), specifically over the entire upper portion of the design layer (115). Meanwhile, if an intermediate layer (117) is provided on the upper portion of the design layer (115), it may be provided to be laminated over the entire upper portion of the intermediate layer (117).

[0061] In addition, since the semi-cured layer (130) is provided on the upper part of the sticker body (110), it has a three-dimensional curved shape identical to the shape of the sticker body (110).

[0062] The semi-cured layer (130) maintains a semi-solid state with some degree of flexibility, and after the sticker body (110) is adhered to the fingernail (M), it hardens and changes into a solid state.

[0063] The semi-cured layer (130) includes a thermosetting component and a photocurable component, and the semi-cured layer (130) can be further photocured after thermosetting. Additionally, the semi-cured layer (130) may additionally include a filler such as glass fiber.

[0064] The semi-cured layer (130) may exist in a dispersed form of a thermosetting component and a photocurable component. The semi-cured layer (130) can be heat-cured by applying heat to a mixture of a thermosetting component and a photocurable component to maintain flexibility, and can be further hardened by photocuring.

[0065] In this embodiment, thermal curing includes not only thermal curing in the conventional sense triggered by thermal crosslinking through heat treatment, but also the concept of partial solidification that occurs when a solvent contained in a polymer or a mixture thereof dries.

[0066] In addition, in this embodiment, the semi-cured layer (130) may maintain some degree of flexibility as uncured photocurable components remain even after thermal curing or partial solidification by such thermal crosslinking.

[0067] The thermosetting component may include any one selected from polyvinyl chloride, polyethylene, polyurethane, polypropylene, polyethylene terephthalate, polyolefin elastomer, ethylene-vinyl acetate copolymer, polystyrene, polyvinylidene chloride, thermoplastic polyurethane, polyester, epoxy resin, acrylic resin, cellulose, polyol, and combinations thereof, and may optionally additionally include a curing agent.

[0068] Any conventional polyol used in the synthesis of polyurethane resins may be used without limitation. The polyol content is not particularly limited and can be determined considering flexibility, hardness, and wear resistance. Furthermore, the curing agent is not particularly limited as long as it is capable of forming the thermosetting component.

[0069] The photocurable component comprises at least one of a photopolymerizable monomer, an oligomer, and a combination thereof, and a photoinitiator.

[0070] For example, the photocurable component may include a polyfunctional epoxy-based (meth)acrylate monomer having at least one epoxy group in the molecule and having two or more functions, a polyfunctional silicon-based (meth)acrylate oligomer having at least one silicon group in the molecule and having five or more functions, and a photoinitiator.

[0071] The above photopolymerizable monomer and oligomer may be, for example, any one of epoxy (meth)acrylate, polyurethane (meth)acrylate, polyester (meth)acrylate, etc.

[0072] A photoinitiator is a reaction that is initiated by the action of light, and examples include ethylphenyl phosphinate, trimethylbenoyl phosphinoxide, alpha-amino ketone, alpha-hydroxy ketone, acylphosphine oxide, benzyldimethyl ketal, benzophenone, cateion (cationic, BASF), metallocene, phenylglyoxylate series initiators, etc., and the scope of the present invention is not limited by these.

[0073] The aforementioned semi-cured layer (130) can be formed by preparing a composition containing a thermosetting component and a photocuring component, applying the liquid semi-cured layer (130) to the upper surface of the design layer (115) or intermediate layer (117), and then heat-curing the liquid semi-cured layer (130). By applying and heat-curing the liquid semi-cured layer (130) in this manner, a semi-cured layer (130) having a shape corresponding to the upper surface shape of the design layer (115) or intermediate layer (117) can be easily prepared.

[0074] The semi-cured layer (130) retains a certain degree of flexibility as the photocurable component remains. The semi-cured layer (130) formed by heat curing exists in a dispersed form of the photocurable component, and the photocurable component can subsequently undergo a photopolymerization reaction by irradiating a predetermined UV light. That is, after the user attaches the sticker body (110) to the fingernail (M), the semi-cured layer (130) can be hardened by photocuring.

[0075] And the semi-cured layer (130) may have a uniform thickness (T2) along the longitudinal direction from the cuticle layer of the nail (M) to the free edge at the center of the upper surface of the sticker body (110), and may have a thickness reduced compared to the thickness (T2) at the center at one end adjacent to the cuticle layer of the nail (M) and at the other end adjacent to the free edge (see FIG. 2). Additionally, the semi-cured layer (130) may have a uniform thickness (T2) along the longitudinal direction of the nail (M) over the entire upper surface of the sticker body (110) (see FIG. 3).

[0076] Conventionally, when a nail sticker (100) is adhered to a fingernail (M) and a semi-cured layer (130) is cured, there was a problem in that the end of the nail sticker (100) protruding outward from the free edge of the fingernail (M) would curl upward. However, since the sticker body (110) according to the present embodiment has a three-dimensional curved surface corresponding to the shape of the fingernail (M), it is possible to prevent the occurrence of a curl at the end of the sticker body (110). Therefore, in the present embodiment, a semi-cured layer (130) having various thicknesses (T2) can be provided on the upper surface of the sticker body (110).

[0077] In this embodiment, the thickness (T1) of the sticker body (110) may be 50 to 300 μm, and the thickness (T2) of the semi-cured layer (130) may be 200 to 1500 μm.

[0078] In addition, the semi-cured layer (130) may have a three-dimensional shape in which the thickness (T2) increases from the cuticle layer of the nail (M) toward the free edge of the nail (M) (see FIG. 4).

[0079] When the semi-cured layer (130) is cured after the nail sticker (100) is attached to the nail (M), the thickness (T2) of the semi-cured layer (130) can be increased from one end of the nail sticker (100) adjacent to the cuticle layer of the nail (M) toward the other end of the nail sticker (100) adjacent to the free edge of the nail (M) so that the cured semi-cured layer (130) may have a three-dimensional curved shape and a three-dimensional dome shape, thereby having an excellent aesthetic similar to that of an artificial nail.

[0080] In this embodiment, the thickness (T1) of the sticker body (110) may be 50 to 300 μm. The thickness (T2) of the semi-cured layer (130) increases from one end of the sticker body (110) adjacent to the cuticle layer of the nail (M) toward the other end of the sticker body (110) adjacent to the free edge of the nail (M), so that the sum of the end thickness (T1) of the sticker body (110) protruding outward from the free edge of the nail (M) and the end thickness (T2) of the semi-cured layer (130), i.e., the end thickness of the nail sticker (100), may be 250 to 4000 μm.

[0081] And the ratio of the thickness of one end of the nail sticker (100) adjacent to the cuticle layer of the nail (M) to the thickness of the other end of the nail sticker (100) adjacent to the free edge of the nail (M) may be 1.5 to 13, and preferably, the ratio of the thickness of one end of the nail sticker (100) to the thickness of the other end may be 2 to 5 so as to have a natural nail (M) shape.

[0082] In FIG. 4, the upper end surface of the semi-cured layer (130) is shown to be formed in a rounded manner, but the upper end surface of the semi-cured layer (130) may be formed in a bent manner.

[0083] Additionally, the semi-cured layer (130) may have a uniform thickness along the width direction of the fingernail (M) at the center of the upper surface of the sticker body (110), and may have a thickness that is reduced compared to the thickness at the center at the end and the other end adjacent to both ends of the fingernail (M) (see FIG. 5). Additionally, the semi-cured layer (130) may have a uniform thickness along the width direction of the fingernail (M) over the entire upper surface of the sticker body (110) (see FIG. 6).

[0084] Meanwhile, as described above, the nail sticker (100) according to the present invention can be arranged to extend outward from the free edge of the fingernail (M). In the past, when the nail sticker (100) was extended outward from the free edge of the fingernail (M), there was a problem in that a curved pattern occurred on the nail sticker (100). However, since the nail sticker (100) according to the present invention has a three-dimensional curved shape, a certain bending strength is imparted to the nail sticker (100) itself, and thereby, when the nail sticker (100) is extended outward from the free edge of the fingernail (M), it is possible to prevent the occurrence of a curved pattern on the nail sticker (100) located on the free edge of the fingernail (M).

[0085] That is, when a nail sticker (100) is attached to a fingernail (M) and the semi-cured layer (130) is not cured, the nail sticker (100) does not have a predetermined bending strength, that is, when the nail sticker is not formed into a three-dimensional curved shape corresponding to the shape of the nail but has a flat shape, if the nail sticker (100) is extended outward from the free edge of the fingernail (M), a curved pattern may be formed on the nail sticker (100) adjacent to the free edge of the fingernail (M), and if the semi-cured layer (130) is cured in this state, the curved pattern remains and may impair the aesthetic appeal. Meanwhile, when the nail sticker (100) is attached to the nail (M) and the semi-cured layer (130) is in a pre-cured state, if the flexibility of the nail sticker (100) is low, that is, if the nail sticker (100) is hard, extending the nail sticker (100) outward from the free edge of the nail (M) can prevent the occurrence of a curved pattern on the nail sticker (100) adjacent to the free edge of the nail (M). However, when manufacturing the nail sticker (100) to be hard, the thickness of the nail sticker (100) increases, so foreign substances may frequently enter between the nail (M) and the nail sticker (100) in the cuticle layer area of ​​the nail (M), or hair may get caught, the fit may be reduced, and the nail sticker (100) may lift off the nail (M).

[0086] Accordingly, the nail sticker (100) according to the present embodiment is designed to have flexibility such that when the upper surface of the center of the nail sticker (100) is pressed with a load of 0.15 to 4.0 N before the semi-cured layer (130) is cured, the lower surface of the center of the nail sticker (100) comes into contact with the ground (the lower surface of the center of the nail sticker (100) becomes flat). This is to prevent the occurrence of a curved pattern by making the nail sticker have a three-dimensional curved shape when extending the nail sticker (100) outward from the free edge of the nail (M), and at the same time, the nail sticker (100) has a certain flexibility to ensure that the nail sticker (100) adheres closely to the upper surface of the nail (M) when adhering to the upper surface of the nail (M).

[0087] Referring to FIG. 7, in this embodiment, a flexibility test of the nail sticker (100) was performed using a material property tester (model name: CTX texture analyzer) from BROOKFIELD. The distance between the supports of both ends of the nail sticker (100) is 10 mm, and the diameter of the probe (cylinder type) that presses the upper surface of the center of the nail sticker (100) is 6 mm. The load applied until the lower surface of the center of the nail sticker (100) becomes flat was measured while pressing the upper surface of the center of the nail sticker (100) with the probe (cylinder type) at a speed of 0.5 mm / s.

[0088] When the semi-cured layer (130) presses the upper surface of the center of the nail sticker (100) before curing so that the lower surface of the center of the nail sticker (100) touches the floor, if the applied load is less than 0.15 N, the flexibility of the nail sticker (100) is high, so when the nail sticker (100) is extended outward from the free edge of the nail (M), a curved pattern may be formed on the nail sticker (100) adjacent to the free edge of the nail (M), and when the semi-cured layer (130) is cured in this state, the curved pattern may remain and impair the aesthetic appeal.

[0089] On the other hand, when the semi-cured layer (130) presses the upper surface of the center of the nail sticker (100) before curing so that the lower surface of the center of the nail sticker (100) touches the floor, if the pressure load exceeds 4.0 N, the flexibility of the nail sticker (100) is small, so when the nail sticker (100) is extended outward from the free edge of the nail (M), it is possible to prevent the occurrence of a curved pattern on the nail sticker (100) adjacent to the free edge of the nail (M), but due to problems such as the thickness of the nail sticker (100) becoming thicker, foreign substances may enter between the nail (M) and the nail sticker (100) in the cuticle layer area of ​​the nail (M) or hair may get caught frequently, the fit may be reduced, and the nail sticker (100) may lift off the nail (M).

[0090] In addition, the nail sticker (100) according to the present invention is used after the semi-cured layer (130) is cured after being attached to the nail (M), and during use, the area protruding outward from the free edge of the nail (M) may be bent or kinked by an external force. Accordingly, in order to prevent the nail sticker (100) from being bent, kinked, broken, or chipped during use when extending the nail sticker (100) outward from the free edge of the nail (M), the nail sticker (100) is made flexible so that when the upper surface of the center of the nail sticker (100) is pressed with a load of 11.0 N or more while the semi-cured layer (130) is cured, the lower surface of the center of the nail sticker (100) is deformed so that it touches the ground (the lower surface of the center of the nail sticker (100) becomes flat).

[0091] When applying pressure to the upper surface of the center of the nail sticker (100) after curing the semi-cured layer (130) so that the lower surface of the center of the nail sticker (100) touches the floor, if the applied pressure is less than 11.05 N, the flexibility of the nail sticker (100) is high, so the area of ​​the nail sticker (100) protruding outward from the free edge of the nail (M) may frequently be bent or kinked by external force during use.

[0092] Meanwhile, when the nail sticker (100) according to the present invention is extended outwardly from the free edge of the fingernail (M), it is preferable that the length of the area protruding outwardly from the free edge of the fingernail (M) does not exceed 2.5 times the length of the area attached to the fingernail (M). This is because it may be susceptible to bending or breaking during use.

[0093] For reference, the average thumb nail length is 12.83 mm, the average index nail length is 11.46 mm, the average middle nail length is 11.81 mm, the average ring nail length is 11.49 mm, and the average little nail length is 9.82 mm (see Journal of the Korean Society of Beauty Science, Vol. 23, No. 3 (2017), pp. 491–497).

[0094] In addition, the nail sticker (100) according to the present invention may further include a protective film (150) that is peelable and provided on the upper surface of the semi-cured layer (130).

[0095] A protective film (150) is provided to be additionally laminated on top of a semi-cured layer (130) to protect the semi-cured layer (130). The protective film (150) may include a material that blocks ultraviolet rays to prevent the photocurable component contained in the semi-cured layer (130) from being cured by ultraviolet rays contained in natural light. Additionally, the protective film can prevent the semi-cured layer (130) from being contaminated by foreign substances.

[0096] The protective film (150) can be manufactured by surface coating silicone, fluorine, etc. on a film or sheet made of any one selected from paper, polyvinyl chloride, polyethylene, polyurethane, polypropylene, polyethylene terephthalate, polyolefin elastomer, ethylene vinyl acetate copolymer, and acrylic resin, or a polymer thereof.

[0097]

[0098] The operation of attaching the nail sticker (100) having a three-dimensional curved shape according to the present invention, configured as described above, to a fingernail is explained as follows.

[0099] FIGS. 8 and 9 are diagrams showing the usage state of a nail sticker having a three-dimensional curved shape according to the present invention, FIG. 10 is a diagram showing the state in which a box sticker is transferred to the lower surface of a nail sticker while the nail sticker having a three-dimensional curved shape according to the present invention is attached to a fingernail, and FIG. 11 is a perspective view showing the state in which a nail sticker having a three-dimensional curved shape according to the present invention is attached to a fingernail.

[0100] Referring to FIG. 8, first, the release liner is peeled off from the sticker body (110). Then, with the release liner peeled off, the adhesive layer (111) is adhered to the fingernail (M). In the case where a protective film (150) is provided on the upper surface of the semi-cured layer (130), the protective film (150) can be peeled off from the semi-cured layer (130) before the adhesive layer (111) is adhered to the fingernail (M).

[0101] Then, the upper surface of the semi-cured layer (130) is pressed to adhere the adhesive layer (111) to the nail (M). At this time, the upper surface of the semi-cured layer (130) is pressed with a predetermined force so that the sticker body (110) does not lift off the upper surface of the nail (M). Conventional nail stickers (100) have a flat shape on their lower surface, so after attaching the nail sticker (100) to the nail (M), the nail sticker (100) is pulled with a predetermined force to prevent wrinkles from forming on the nail sticker (100) and is adhered to the shape of the nail (M). However, since the nail sticker (100) according to the present embodiment has a three-dimensional curved shape, the nail sticker (100) can be adhered to the nail (M) by only pressing the upper surface of the nail sticker (100), that is, the semi-cured layer (130), downward, thereby improving convenience of use.

[0102] Then, referring to FIG. 9, after attaching the nail sticker (100) to the fingernail (M), UV light is irradiated to cure the semi-cured layer (130). When the semi-cured layer (130) is cured, only the sticker body (110) and the cured semi-cured layer (130) remain attached to the upper surface of the fingernail (M).

[0103] Meanwhile, when the nail sticker (100) extends outward from the free edge of the nail (M), the adhesive layer (111) may be exposed to the outside and contaminated. Therefore, to prevent the adhesive layer (111) from being contaminated as shown in FIG. 10, a box sticker (170) can be attached to the adhesive layer (111) provided on the lower surface of the nail sticker (100) that extends outward from the free edge of the nail (M).

[0104] FIG. 11 shows a state in which a nail sticker (100) is attached to a fingernail (M) and a box sticker (170) is attached to an adhesive layer (111), and the nail sticker (100) is extended outwardly from the free edge of the fingernail (M). Since the nail sticker (100) according to the present embodiment has a three-dimensional curved shape, when attached to the fingernail (M), it can have an improved fit compared to a conventional nail sticker (100), and can be arranged to extend outwardly from the free edge of the fingernail (M) to achieve an aesthetic similar to an artificial nail.

[0105]

[0106] As such, it is obvious to those skilled in the art that the present invention is not limited to the described embodiments and can be modified and varied in various ways without departing from the spirit and scope of the invention. Accordingly, such modified or varied embodiments should be deemed to fall within the scope of the claims of the present invention.

[0107] [Explanation of the symbol]

[0108] 100: Nail sticker 110: Sticker body

[0109] 111: Adhesive layer 113: Substrate layer

[0110] 115: Design layer 117: Intermediate layer

[0111] 130: Semi-cured layer 150: Protective film

[0112] 170: Box Sticker

[0113] The nail sticker having a three-dimensional curved shape of the present invention can further improve the fit and can also extend outward from the fingernail, etc.

Claims

1. A nail sticker comprising a sticker body having a lower surface that adheres to a fingernail, is flexible, and has a three-dimensional curved shape corresponding to the shape of a fingernail, and a semi-cured layer provided on the upper surface of the sticker body, The nail sticker has flexibility and has a three-dimensional curved shape corresponding to a nail shape so as to have a predetermined bending strength in the state before the semi-cured layer is cured.

2. In Paragraph 1, The above-mentioned semi-cured layer is a nail sticker having a three-dimensional curved shape with a uniform thickness in the free edge direction from the cuticle layer of the nail.

3. In Paragraph 2, A nail sticker having a three-dimensional curved shape, wherein the thickness of one end adjacent to the cuticle layer of the nail and the other end adjacent to the free edge of the semi-cured layer is reduced compared to the thickness of the center.

4. In Paragraph 1, The above-mentioned semi-cured layer is a nail sticker having a three-dimensional curved shape, having a three-dimensional shape in which the thickness increases from the cuticle layer of the nail toward the free edge.

5. In Paragraph 4, A nail sticker having a three-dimensional curved shape, wherein the ratio of the thickness of one end of the nail sticker adjacent to the cuticle layer of the nail to the thickness of the other end of the nail sticker adjacent to the free edge of the nail is 1.5 to 13.

6. In Paragraph 1, A nail sticker having a three-dimensional curved shape having flexibility such that when the upper surface of the center of the nail sticker is pressed with a load of 0.15 to 4.0 N in a state before the semi-cured layer is cured, the lower surface of the center of the nail sticker becomes flat due to deformation.

7. In Paragraph 1, A nail sticker having a three-dimensional curved shape having flexibility such that when the upper surface of the center of the nail sticker is pressed with a load of 11.0 N or more while the semi-cured layer is cured, the lower surface of the center of the nail sticker becomes flat due to deformation.

8. In Paragraph 1, The above nail sticker is a nail sticker having a three-dimensional curved shape that can be extended outwardly from the free edge of the nail.

9. In Paragraph 1, The above-mentioned semi-cured layer includes a photocuring component, and A nail sticker having a three-dimensional curved shape, wherein the semi-cured layer is photocured after the nail sticker is adhered to a fingernail.

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