Nail sticker, method for manufacturing the nail sticker, and nail sticker set including the nail sticker

Abstract

The present invention relates to a nail sticker that can be cured by ultraviolet light, and a lower surface of the nail sticker before being cured by ultraviolet light may include a curved surface that is curved such that a center of the nail sticker is directed upward.

Description

[Technical Field]

[0001] The present invention relates to a nail sticker, a method for manufacturing the nail sticker, and a nail sticker set including the nail sticker. [Background technology]

[0002] As one of the ways people pursue physical beauty, the beauty industry has been developing at an accelerated pace and becoming more specialized. In particular, since the 20th century, the beauty industry has begun to popularize itself among the general public with the rapid expansion of the market. Within the beauty industry, nail art has rapidly developed in recent years as an essential element of artistic expression for the body, regardless of age or gender.

[0003] Originally, nail art was a field of beauty art, a way to beautifully decorate the human body, and the length, shape, and color of nails have been expressed to reflect the cultural changes and values ​​of the times.

[0004] Among nail art styles, nail stickers in the shape of artificial fingernails or toenails are widely used. Previously, nail stickers were manufactured and supplied to consumers in a curved shape, drawing a curve like a fingernail or toenail. These nail stickers were supplied to consumers in a hardened state as an extruded product. However, because the shape (especially the curvature) of each person's fingernail or toenail varies, there was a problem in that the nail stickers, which have a naturally curved shape, were difficult to adhere closely to the consumer's fingernail or toenail.

[0005] As a solution to this problem, nail stickers containing UV-curable materials have recently gained attention. Specifically, nail stickers containing UV-curable materials have a flat bottom surface, and the user (consumer) deforms the nail sticker to fit their fingernail or toenail, then irradiates it with UV light to harden the nail sticker. This allows the nail sticker to adhere closely to the consumer's fingernail or toenail, improving the adhesive strength of the nail sticker. Such nail stickers are also called gel nail stickers.

[0006] For various reasons, the thickness of a gel nail sticker may be increased. For example, if the gel nail sticker is long and extends beyond the edge of the fingernail or toenail in addition to the area where it overlaps the nail, the thickness may be increased in order to maintain that shape. Furthermore, even if the reasons are not necessarily those mentioned above, the thickness of a gel nail sticker may be increased for cosmetic reasons.

[0007] If the gel nail sticker is thick like this, even if a user applies force to the gel nail sticker to change its shape to fit their fingernail or toenail, the gel nail sticker will likely return to its original shape, making it difficult to wear the gel nail sticker to fit the shape of their fingernail or toenail.

[0008] Therefore, there is a need for new technologies that allow users to more effectively apply gel nail stickers to their fingernails or toenails. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Republic of Korea Patent Publication No. 10-2019-0014044 Summary of the Invention [Problem to be solved by the invention]

[0010] One problem to be solved by the present invention is to provide a nail sticker that can be easily shaped by a user to fit the shape of their own nails (fingernails or toenails).

[0011] Another object of the present invention is to provide a method for manufacturing the nail sticker.

[0012] Another object of the present invention is to provide a nail sticker set including the nail sticker. [Means for solving the problem]

[0013] According to one embodiment of the present invention, there is provided a nail sticker that can be cured by ultraviolet light, wherein the lower surface of the nail sticker before being cured by ultraviolet light includes a curved surface in which the center of the nail sticker is curved upward.

[0014] According to another embodiment of the present invention, there is provided a method for manufacturing a nail sticker, which includes a first step of placing a preliminary nail sticker that can be cured by ultraviolet light on a support part included in a support structure; and a second step of applying pressure to an upper surface of the preliminary nail sticker to bring a lower surface of the preliminary nail sticker into close contact with an upper surface of the support part, wherein the support part has a curved surface that is convex toward an upper side, and the lower surface of the nail sticker before being cured by ultraviolet light includes a curved surface that is curved so that the center of the nail faces toward the upper side.

[0015] According to yet another embodiment of the present invention, a support structure including a support portion; and A nail sticker set is provided, which includes a nail sticker attached to an upper surface of the support, the upper surface of the support having a curved surface that is curved so that the center of the sticker faces upward, the nail sticker being curable by ultraviolet light, and the lower surface of the nail sticker before being cured by ultraviolet light having a curved surface that is curved so that the center of the nail sticker faces upward. [Effects of the Invention]

[0016] According to the present invention, compared to existing nail stickers that have a flat bottom surface, the bottom surface of the nail sticker of the present invention before hardening includes a curved surface in which the center of the nail sticker is curved upward, making it easier for users to shape the nail sticker to fit the shape of their own nails.

[0017] In addition, the nail sticker maintains its shape well even during the process of application and hardening by the user, making it easy for the user to use and allowing the user to wear a nail sticker that better suits their nails. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram of a nail sticker according to an embodiment of the present invention; [Figure 2] 1 is a photograph of a nail sticker according to an embodiment of the present invention. [Figure 3] 1 is a top view of a nail sticker according to an embodiment of the present invention. [Figure 4] 4 is a cross-sectional view of the nail sticker taken along the line xx′ in FIG. 3. [Figure 5] 1 is a cross-sectional view of a preliminary nail sticker before being placed on a support. FIG. [Figure 6] 1 is a schematic diagram of a support as described herein. [Figure 7] 10A to 10C are schematic diagrams illustrating a method for manufacturing a nail sticker according to another embodiment of the present invention. [Figure 8] 10A to 10C are schematic diagrams illustrating a method for manufacturing a nail sticker according to another embodiment of the present invention. [Figure 9] 10A to 10C are schematic diagrams illustrating a method for manufacturing a nail sticker according to another embodiment of the present invention. [Figure 10] 1 is a schematic diagram of a nail sticker set according to an embodiment of the present invention. [Figure 11] 1 is a photograph of a nail sticker set according to an embodiment of the present invention. [Figure 12] 1 is a photograph of a nail sticker set according to an embodiment of the present invention. [Figure 13] This is a photograph of a nail sticker according to Example 1 of the present invention, specifically, a photograph of a nail sticker manufactured through steps 1 to 3 of the nail sticker manufacturing method described in the present invention immediately after being peeled off from the support. [Figure 14] This is a photograph of a nail sticker according to Example 1 of the present invention, specifically, after the first and second steps of the nail sticker manufacturing method described in the present invention, the nail sticker is peeled off from the support and left for 24 hours. [Figure 15] This is a photograph of a nail sticker according to Example 2 of the present invention, specifically a photograph of a nail sticker manufactured through the first and second steps of the nail sticker manufacturing method described in the present invention immediately after being peeled off from the support. [Figure 16] This is a photograph of a nail sticker according to Example 2 of the present invention, specifically, after the first and second steps of the nail sticker manufacturing method described in the present invention, the nail sticker is peeled off from the support and left for 24 hours. [Figure 17] 1 is a photograph of a nail sticker according to Comparative Example 1 of the present invention, taken immediately after the manufactured nail sticker was peeled off from the support. [Figure 18]This is a photograph of a nail sticker according to Comparative Example 1 of the present invention, specifically, after the first and second steps of the nail sticker manufacturing method described in the present invention, the nail sticker was peeled off from the support and left for 24 hours. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE INVENTION The present invention is susceptible to various modifications and embodiments, and therefore specific embodiments are shown by way of example in the drawings and will be described in detail in the detailed description.

[0020] However, it should be understood that this is not intended to limit the present invention to the specific embodiment, and includes all modifications, equivalents, and alternatives that fall within the spirit and technical scope of the present invention. In describing the present invention, if it is determined that a detailed description of related publicly known technology would obscure the gist of the present invention, the detailed description will be omitted.

[0021] The terms used in this application are merely used to describe specific embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless otherwise clearly indicated in the context.

[0022] In the present invention, the terms "comprise" or "have" and the like are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described herein, and should be understood not to preclude the presence or possible addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0023] In the present invention, being placed or located "on" can mean not only being in direct contact with an object, but also being placed or located on an object at a distance.

[0024] By nail herein is meant fingernails and / or toenails.

[0025] The thickness measured in the present invention can be confirmed through a Keyence VHX-970F device.

[0026] In this specification, the "maximum thickness" of a certain component means the thickest thickness of the component measured in a vertical direction from any fulcrum on the lower surface of the component.

[0027] The upper surface of the nail sticker in this specification refers to the surface exposed toward the upper direction when the R direction in FIGS. 1 and 4 is the upper direction. Specifically, the upper surface of the nail sticker may be the surface where the coating layer is exposed to the outside. The lower surface of the nail sticker in this specification refers to the surface exposed toward the lower direction when the R' direction in FIGS. 1 and 4 is the lower direction. Specifically, the upper surface of the nail sticker may be the surface where the base layer (specifically, the adhesive layer of the base layer) is exposed to the outside.

[0028] In this specification, the test for confirming the deformation rate can be performed with the nail sticker placed on a flat floor as shown in FIG.

[0029] The nail sticker of the present invention can be a nail sticker that can be deformed by the user to fit the user's nail and can be cured by ultraviolet light when attached to the user's nail. Such a nail sticker is also called a gel nail sticker.

[0030] Therefore, the nail sticker of the present invention can refer to nail stickers that are not cured by ultraviolet light (when the user is not irradiating them with ultraviolet light). In other words, it can refer to the nail sticker of one embodiment of the present invention, the nail sticker manufactured by the nail sticker manufacturing method of another embodiment of the present invention, and all of the nail stickers included in the nail sticker set of yet another embodiment of the present invention, all of which are not cured by ultraviolet light (when the user is not irradiating them with ultraviolet light).

[0031] In this specification, when the nail sticker is cured by ultraviolet irradiation, the ultraviolet irradiation conditions may mean irradiation with ultraviolet light having a wavelength of 100 nm to 400 nm at an output of 100 W to 1800 W for 10 to 40 seconds.

[0032] <Nail stickers> The nail sticker refers to an artificial laminated structure manufactured for application to nails (fingernails and / or toenails). When considered for application to be applied, it is also called nail art or nail art sticker.

[0033] Specifically, when a consumer is provided with the nail sticker, the consumer can attach the nail art to the nail by deforming the shape of the nail sticker so that the nail sticker adheres tightly to the nail, and then irradiate the nail sticker with ultraviolet light to harden it.

[0034] A nail sticker according to an embodiment of the present invention is a nail sticker that can be cured by ultraviolet light, and a lower surface of the nail sticker before being cured by ultraviolet light may include a curved surface that is curved such that the center of the nail sticker is directed upward.

[0035] Fig. 1 is a schematic diagram of a nail sticker according to an embodiment of the present invention, and Fig. 2 is a photograph of the nail sticker. Referring to Fig. 1 and Fig. 2, the nail sticker according to an embodiment of the present invention may be in the shape of a nail. The nail sticker has an uneven bottom surface and a curved, convex shape.

[0036] 3 is a top view of a nail sticker according to an embodiment of the present invention. Referring to FIG. 3, the nail sticker can include a major axis and a minor axis. The major axis corresponds to an axis including an imaginary line segment corresponding to the longest arm of the nail sticker in the direction from the base of the nail to the end of the nail (the end adjacent to the fulcrum where the fingertip ends) when the nail sticker is worn on the nail (yy' in FIG. 3).

[0037] Here, the length of the nail sticker refers to the size of the nail sticker in the direction from the base of the nail to the end of the nail (the end adjacent to the fulcrum where the fingertip ends) when the nail sticker is attached to the nail. The minor axis is perpendicular to the major axis and corresponds to an axis including an imaginary line segment corresponding to the width of the nail (the distance between the two edges of the nail sticker adjacent to both sides of the nail) when the nail sticker is attached to the nail, and the length of the nail sticker can be accurately divided into two by the shortening. The center 100a of the nail sticker refers to the fulcrum where the major axis and minor axis of the nail intersect.

[0038] 1 to 4, the lower surface 100b of the nail sticker before being cured by ultraviolet light may include a curved surface in which the center 100a of the nail sticker is curved upward. That is, the nail sticker of the present invention may have a shape in which the flat lower surface is bent by an external force and the center 100a of the nail sticker is curved upward.

[0039] Similarly, the upper surface of the nail sticker may include a curved surface that is curved so that the center 100a of the nail sticker faces upward. More specifically, when the nail sticker is placed on a flat floor so that the lower surface of the nail sticker before being cured by ultraviolet light faces the flat floor, the center 100a of the nail sticker may be spaced apart from the floor.

[0040] Here, the lower surface 100b of the nail sticker may refer to the surface facing the user's nail, and specifically may be the surface including the surface where the adhesive layer is exposed to the outside. When the nail sticker is placed on a flat floor with the lower surface of the nail sticker before being cured by ultraviolet light facing the flat floor, at least a portion of the edge of the nail sticker may come into contact with the flat floor.

[0041] This shape is rarely seen in conventional nail stickers that are curable by ultraviolet light. Specifically, in the case of injection-molded hard nail stickers, if a nail-shaped mold is used, the bottom surface of the nail sticker can be manufactured to have a curved surface with the center of the nail sticker pointing upward. However, UV-curable nail stickers must be flexible enough for users to mold them to the shape of their own nails, so soft materials must be used.

[0042] When using such materials, if nail stickers are manufactured using a nail-shaped mold, the material can burn inside the mold. Furthermore, according to conventional nail sticker manufacturing methods, nail stickers are manufactured by stacking layers that make up the nail sticker on a flat surface, which inevitably results in the bottom surface of the nail sticker becoming flat. When an external force is applied to a "flat-bottom nail sticker" manufactured to give the bottom surface of a conventional UV-curable nail sticker the curved surface described above, the shape is deformed the moment the external force is applied, but the nail sticker tends to return to its flat shape as soon as the external force is removed.

[0043] That is, with conventional technology, it has never been possible to manufacture nail stickers (gel nail stickers) that can be cured by ultraviolet light into curved shapes like nails.

[0044] However, in the case of the nail sticker of the present invention, since it contains a layer not found in the past, it can have a curved shape like a nail. Furthermore, "being able to have a curved shape" can mean that the nail sticker can maintain the curved shape to a considerable extent.

[0045] Furthermore, the nail sticker of the present invention can be manufactured by a manufacturing method that has not been used in the past, so that the nail sticker can more effectively maintain its curved shape.

[0046] In short, the nail sticker of the present invention has a major feature in that the lower surface of the nail sticker before being hardened by ultraviolet light can include a curved surface that causes the center of the nail sticker to face upward, without any external force (excluding natural forces such as gravity) being intentionally applied to the nail sticker.

[0047] For example, the nail sticker of the present invention is curved so that the center of the underside of the nail sticker is curved upward, and when the nail sticker is placed on a flat floor with the underside facing the floor, it is possible that the center of the underside of the nail sticker will not come into contact with the flat floor even after 24 hours.

[0048] The nail sticker may include a soft layer, and the soft layer may include a resin for the soft layer, and the resin for the soft layer may include at least one of cellulose acetate butyrate and cellulose acetate propionate.

[0049] Therefore, in the manufacturing process of the nail sticker according to the embodiment of the present invention, the nail sticker can be easily deformed into a nail shape and the deformed shape of the nail sticker can be effectively maintained. That is, the use of the soft layer is a main factor that enables the lower surface of the nail sticker before being hardened by ultraviolet light to have a curved surface with the center of the nail sticker curved upward.

[0050] In addition, when a user applies a certain amount of force during the process of applying the nail sticker, the soft layer fills the gap between the nail and the nail sticker, effectively maintaining the filled shape, thereby reducing the foreign body sensation felt by the user and increasing the adhesive strength of the nail sticker.

[0051] Furthermore, when a portion of the nail sticker extends beyond the nail area, the soft layer can support the extended portion of the nail sticker so that it does not deform. Even if the nail surface is uneven, applying a certain force can deform the nail so that more of the soft layer is placed on the concave portion of the nail surface.

[0052] Therefore, even if the nail surface is uneven, the surface of the applied nail sticker can have a smooth shape, improving aesthetics. Furthermore, the cellulose acetate butyrate and the cellulose acetate propionate have the advantage of superior shock absorption compared to other materials.

[0053] More specifically, the resin for the soft layer may include cellulose acetate butyrate. For example, the resin for the soft layer may be cellulose acetate butyrate. This resin has excellent impact absorption and durability, and when mixed with the UV-curable raw material for the soft layer, its ductility increases. Therefore, deformation of the soft layer due to external impact occurs irreversibly due to the impact absorption effect, and once deformed, the shape can be more easily maintained. Therefore, nail stickers with a nail shape can be provided to users.

[0054] The resin for the soft layer may be contained in the soft layer in an amount of 10% to 90% by weight, specifically 15% to 75% by weight, and more specifically 30% to 65% by weight. When the content of the resin for the soft layer is within this range, the soft layer can be easily deformed at body temperature and can maintain the shape of the deformed soft layer. Therefore, a nail sticker with a nail shape can be provided to the user.

[0055] The soft layer may further include an ultraviolet curing material for the soft layer, so that the soft layer can be cured by ultraviolet irradiation.

[0056] The UV-curable raw material for the soft layer may include at least one selected from the group consisting of urethane acrylate oligomers, polyester acrylate oligomers, polyether acrylate oligomers, epoxy acrylate oligomers, polycarbonate acrylate oligomers, silicone acrylate oligomers, and acrylic acrylate oligomers.

[0057] Specifically, the UV-curable material for the soft layer may include at least one of a urethane acrylate oligomer, a polyester acrylate oligomer, and an epoxy acrylate oligomer.

[0058] The urethane acrylate oligomer is advantageous because it is easily cured by ultraviolet light and maintains a predetermined flexibility even after curing. Furthermore, it can minimize haze, thereby maintaining the transparency of the coating layer. The urethane acrylate oligomer may include at least one of a difunctional urethane acrylate oligomer, a tetrafunctional urethane acrylate oligomer, a hexafunctional urethane acrylate oligomer, and a nonafunctional urethane acrylate oligomer.

[0059] Specifically, the urethane acrylate oligomer may include at least one selected from the group consisting of PU210, PU280, PU640, and SC2404, which are products of Miwon, and CN9033 and CN9047, which are products of SATOMER. The weight-average molecular weight of the urethane acrylate oligomer may be 1,000 g / mol to 1,000,000 g / mol, specifically 1,000 g / mol to 100,000 g / mol. When the weight-average molecular weight satisfies this range, workability can be significantly improved.

[0060] The epoxy acrylate oligomer has high reactivity, good hardness and abrasiveness, is easy to cure, has excellent flexibility, and can cure stably even when exposed to oxygen. The epoxy acrylate oligomer may have one or two functional groups. A single functional group exhibits ductility, and the greater the number of functional groups, the better the rigidity or thermal stability.

[0061] Specifically, the epoxy acrylate oligomer may include at least one selected from the group consisting of PE210, PE2120, and PE250, which are products of Miwon Co., Ltd. The weight-average molecular weight of the epoxy acrylate oligomer may be 100 g / mol to 10,000 g / mol, specifically 500 g / mol to 6,000 g / mol. Considering the solid content and viscosity of the soft layer-forming composition, the weight-average molecular weight is preferably within the above range.

[0062] The polyester acrylate oligomer has excellent reactivity and adhesive properties superior to those of urethane acrylate oligomers and epoxy acrylate oligomers. The polyester acrylate oligomer may be an oligomer having four or six functional groups.

[0063] Specifically, the polyester acrylate oligomer may include at least one selected from the group consisting of PS4040, PS460, PS6300, Etermer 6311-100, 6312-100, and 6314C-60, all of which are products of Miwon. The weight-average molecular weight of the polyester acrylate oligomer may be 500 g / mol to 50,000 g / mol, specifically 1,500 g / mol to 38,000 g / mol. When the weight-average molecular weight satisfies this range, processability and adhesive strength can be improved.

[0064] In the soft layer, the epoxy acrylate oligomer may be contained in an amount of 1 to 10 parts by weight, specifically 1 to 3 parts by weight, per 100 parts by weight of the urethane acrylate oligomer. In the soft layer, the polyester acrylate oligomer may be contained in an amount of 10 to 20 parts by weight, specifically 2 to 8 parts by weight, per 100 parts by weight of the urethane acrylate oligomer. When the above composition is satisfied, rapid hardening does not occur even when the soft layer is exposed to air, and durability can be maintained even after the nail sticker is attached.

[0065] Alternatively, the UV-curable raw material for the soft layer may include the urethane acrylate oligomer, and more specifically, may consist of the urethane acrylate oligomer.

[0066] The UV-curable raw material for the soft layer may be contained in the soft layer in an amount of 10 to 90% by weight, specifically 15 to 75% by weight, more specifically 30 to 65% by weight. When the above range is satisfied, the soft layer maintains its soft properties before UV irradiation, but becomes very hard after curing by UV irradiation.

[0067] In the soft layer, the weight ratio of the soft layer UV-curable raw material to the soft layer resin may be 10:90 to 90:10, specifically 20:80 to 80:20, more specifically 30:70 to 70:30. When the weight ratio is within this range, the impact absorption properties of the soft layer resin and the viscosity of the soft layer UV-curable raw material are combined, resulting in an increased ability to absorb external impact energy.

[0068] The photoinitiator for the soft layer serves to initiate a polymerization reaction when irradiated with ultraviolet light, and specifically, the photoinitiator may be an ultraviolet photoinitiator.

[0069] The photoinitiator for the soft layer may have an absorption wavelength band in the range of 200 nm to 600 nm.

[0070] The photoinitiator for the soft layer may include at least one selected from the group consisting of trimethylbenzoyl phosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone, but is not necessarily limited thereto.

[0071] The photoinitiator for the soft layer may be contained in the soft layer in an amount of 1 wt % to 10 wt %, specifically 1 wt % to 8 wt %, more specifically 2 wt % to 7 wt %. When this range is satisfied, the nail sticker can have an appropriate hardness when the user hardens the nail sticker.

[0072] The maximum thickness of the soft layer may be 250 μm to 2500 μm, specifically 700 μm to 2400 μm, more specifically 1000 μm to 2000 μm. When the thickness is within this range, the nail sticker of the present invention can be easily manufactured, in which the lower surface of the nail sticker before being cured by ultraviolet light includes a curved surface in which the center of the nail sticker is curved toward the upper side.

[0073] In addition, when the above range is satisfied, a sufficient portion of the soft layer can be moved to minimize lift between the nail sticker and the nail. Furthermore, when a portion of the nail sticker extends beyond the nail area, the soft layer can more effectively support the extended and protruding portion of the nail sticker so that it is not deformed.

[0074] Furthermore, even if the nail surface is uneven, the movement of the soft layer allows more of the soft layer to be positioned sufficiently on the concave portions of the nail, so the surface of the applied nail sticker can have a smoother shape.

[0075] In addition, since the soft layer may not have a high rate of change even when subjected to an external impact, the effect can be smoothly maintained. The maximum thickness of the soft layer may mean the largest thickness of the soft layer measured in a vertical direction from any fulcrum on the lower surface of the soft layer.

[0076] The soft layer may be a single layer, or alternatively, may be made up of two or more layers.

[0077] The nail sticker may further include a base layer, and the soft layer may be disposed on the base layer.

[0078] 4, the upper surface of the base layer 120 and the lower surface of the soft layer 110 may face each other or may be in contact with each other. That is, the soft layer 110 may be positioned on the base layer 120.

[0079] The base layer may include an adhesive layer that provides chemical adhesion for attaching the nail sticker to a nail, and the adhesive layer may be located below the nail sticker and constitute at least a portion of the lower surface of the nail sticker.

[0080] The adhesive layer may constitute at least a part of the bottom surface of the nail sticker. The adhesive layer may include an adhesive component, which may correspond to an adhesive component commonly used in the art.

[0081] The base layer may further include a design layer. The design layer may be located between the adhesive layer and the soft layer. The design layer may include at least one of a color layer and a print layer. The design layer may include a pigment that imparts color to the nail sticker. The print layer may include particles for expressing shapes, various materials for aesthetic purposes, such as mica, etc.

[0082] A base film may be disposed on the lower surface of the base layer. The base film serves to prevent contamination of the adhesive layer and maintain adhesive strength before use of the nail sticker, and is removed when the nail sticker is used. The base film may include components commonly used in the art.

[0083] The nail sticker may further include a coating layer.

[0084] Referring to FIG. 4, in the nail sticker 100, the coating layer 130 may be located on the soft layer 110.

[0085] The coating layer may include an ultraviolet curable material for the coating layer and a resin for the coating layer.

[0086] Since the UV-curable coating layer material is included in the coating layer, the user can deform the nail sticker to fit closely to their own nails, and then irradiate it with UV light to harden the nail sticker according to the deformed shape. As a result, the nail sticker and fingernail / toenail can be bonded together in a completely tight contact state, improving the adhesive strength of the nail sticker.

[0087] The UV-curable raw material for the coating layer may include at least one selected from the group consisting of urethane acrylate oligomers, polyester acrylate oligomers, polyether acrylate oligomers, epoxy acrylate oligomers, polycarbonate acrylate oligomers, silicone acrylate oligomers, and acrylic acrylate oligomers.

[0088] Specifically, the UV-curable raw material for the coating layer may include at least one of a urethane acrylate oligomer, a polyester acrylate oligomer, and an epoxy acrylate oligomer.

[0089] The urethane acrylate oligomer is advantageous because it is easily cured by ultraviolet light and has a predetermined flexibility even after curing. In addition, it can minimize haze and maintain the transparency of the coating layer.

[0090] The urethane acrylate oligomer may include at least one of a difunctional urethane acrylate oligomer, a tetrafunctional urethane acrylate oligomer, a hexafunctional urethane acrylate oligomer, and a nonafunctional urethane acrylate oligomer.

[0091] Specifically, the urethane acrylate oligomer may include at least one selected from the group consisting of PU210, PU280, PU640, and SC2404, which are products of Miwon, and CN9033 and CN9047, which are products of SATOMER. The weight-average molecular weight of the urethane acrylate oligomer may be 1,000 g / mol to 1,000,000 g / mol, specifically 1,000 g / mol to 100,000 g / mol. When the weight-average molecular weight satisfies this range, workability can be significantly improved.

[0092] The epoxy acrylate oligomer has high reactivity, good hardness and abrasiveness, is easily cured, has excellent flexibility, and can be cured stably even when exposed to oxygen. The epoxy acrylate oligomer may have one or two functional groups. A single functional group exhibits ductility, and a higher number of functional groups is advantageous in terms of rigidity or thermal stability.

[0093] Specifically, the epoxy acrylate oligomer may include at least one selected from the group consisting of PE210, PE2120, and PE250, which are products of Miwon Co., Ltd. The weight-average molecular weight of the epoxy acrylate oligomer may be 100 g / mol to 10,000 g / mol, specifically 500 g / mol to 6,000 g / mol. Considering the solid content and viscosity of the composition for forming a coating layer, the weight-average molecular weight is preferably within this range.

[0094] The polyester acrylate oligomer has excellent reactivity and adhesive properties superior to those of urethane acrylate oligomers and epoxy acrylate oligomers. The polyester acrylate oligomer may be an oligomer having four or six functional groups. Specifically, the polyester acrylate oligomer may include at least one selected from the group consisting of PS4040, PS460, PS6300, Etermer 6311-100, 6312-100, and 6314C-60, all of which are products of Miwon.

[0095] The weight-average molecular weight of the polyester acrylate oligomer may be 500 g / mol to 50,000 g / mol, specifically 1,500 g / mol to 38,000 g / mol. When the weight-average molecular weight is within this range, processability and adhesive strength can be improved.

[0096] In the coating layer, the epoxy acrylate oligomer may be contained in an amount of 1 part by weight to 10 parts by weight, specifically 1 part by weight to 3 parts by weight, relative to 100 parts by weight of the urethane acrylate oligomer.

[0097] In the coating layer, the polyester acrylate oligomer may be contained in an amount of 10 parts by weight to 20 parts by weight, specifically 2 parts by weight to 8 parts by weight, relative to 100 parts by weight of the urethane acrylate oligomer.

[0098] When the composition satisfies the above criteria, rapid hardening does not occur even when the coating layer is exposed to air, and durability can be maintained even after the nail sticker is attached.

[0099] Alternatively, the UV-curable raw material for the coating layer may include the urethane acrylate oligomer, and more specifically, may consist of the urethane acrylate oligomer.

[0100] The UV-curable raw material for the coating layer may be contained in the coating layer in an amount of 10 to 90% by weight, specifically 10 to 60% by weight, more specifically 20 to 50% by weight. When the amount satisfies this range, the coating layer maintains flexible properties before UV irradiation, but becomes very hard after curing by UV irradiation.

[0101] The resin for the coating layer may control the fluidity of the coating layer to maintain its shape, and the resin for the coating layer may also allow the composition for forming the coating layer to have an appropriate viscosity, thereby enabling the coating layer to be formed in a desired shape.

[0102] The resin for the coating layer may be a thermoplastic resin having a glass transition temperature (Tg) of 30° C. to 200° C., specifically 50° C. to 120° C. When the resin for the coating layer satisfies this range, the mobility of the resin for the coating layer is not high at room temperature, but the resin for the coating layer is appropriately mixed with the UV-curable raw material in a drying oven during the manufacturing process of the nail sticker, and the horizontal lines of the nail sticker can be smoothly formed.

[0103] The resin for the coating layer may include at least one selected from the group consisting of a resin for an acrylic coating layer, a resin for a nitrocellulose coating layer, a resin for an epoxy coating layer, a resin for a polyester coating layer, a resin for a polyvinyl coating layer, a resin for a urethane coating layer, and a resin for a vinyl acetate coating layer.

[0104] In particular, the resin for the coating layer may include an acrylic resin for the coating layer and a nitrocellulose resin for the coating layer. The glass transition temperature (Tg) of the acrylic resin for the coating layer may be 30°C to 200°C, specifically 50°C to 120°C. The resin for the nitrocellulose coating layer may include Korea CNC HRS1 / 8~20SS type 1 / 8~1 / 2.

[0105] The nitrogen content of the resin for the nitrocellulose coating layer may be 11.5% to 12.2%, specifically, 1 / 8 second to 20 seconds depending on the viscosity. When this range is satisfied, low viscosity can be maintained and the solid content can be increased.

[0106] The resin for the coating layer may be contained in the coating layer in an amount of 10 to 90% by weight, specifically 15 to 75% by weight, more specifically 15 to 70% by weight. When the resin for the coating layer is contained in the coating layer in an amount within this range, the coating layer is sufficiently non-sticky that it can be handled at room temperature without any problems, and a round shape can be formed.

[0107] Meanwhile, the resin for the coating layer may include a thermosetting resin for the coating layer and a thermal initiator.

[0108] The coating layer may further include a photoinitiator for the coating layer.

[0109] The photoinitiator serves to initiate a polymerization reaction upon irradiation with ultraviolet light, and specifically, the photoinitiator may be an ultraviolet photoinitiator.

[0110] The photoinitiator may have an absorption wavelength band in the range of 200 nm to 600 nm.

[0111] The photoinitiator may include at least one selected from the group consisting of trimethylbenzoyl phosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone, but is not necessarily limited thereto.

[0112] The photoinitiator may be contained in the coating layer in an amount of 1 wt % to 10 wt %, specifically 1 wt % to 8 wt %, more specifically 2 wt % to 7 wt %. When the amount of the photoinitiator is within this range, the coating layer can have an appropriate hardness when cured by a user.

[0113] In some cases, the coating layer may contain a solvent. The solvent corresponds to the solvent used in forming the coating layer-forming composition for producing the coating layer, and is removed by drying during the production process of the coating layer. However, a small amount of the solvent may remain in the coating layer.

[0114] The nail sticker may further include a design expression layer disposed on the coating layer, which may be used to express a matte finish or a thick film-type three-dimensional figure such as a three-dimensional line, a cone, or a circular dome.

[0115] The maximum thickness of the nail sticker may be 500 μm to 2,500 μm, specifically 700 μm to 2,000 μm, more specifically 1,000 μm to 1,800 μm. When the thickness is within this range, the nail sticker has a high aesthetic appearance, does not crack when cured by ultraviolet light, and reduces the phenomenon of pinching the nail.

[0116] When the nail sticker is placed on a flat floor with the underside of the nail sticker before being hardened by ultraviolet light facing the flat floor, the deformation rate according to the following formula 1 in an atmosphere at a temperature of 25°C may be 4% or less, specifically 0% to 3%, more specifically 0% to 2.1%.

[0117] [Formula 1] Deformation ratio = [(BA) / A] x 100 In the formula 1, The A may refer to the maximum width of the nail sticker measured immediately after the nail sticker is placed on the flat floor, and the B may refer to the maximum width of the nail sticker measured one hour after the nail sticker is placed on the flat floor. In this specification, "on a flat floor" may refer to directly above a flat floor.

[0118] The nail sticker has a deformation rate of 30% or less according to the following formula 1 in an atmosphere at a temperature of 25°C, so the shape of the nail sticker can be maintained to the maximum extent even during the process of delivering the product to the user. In addition, the user can more easily shape the nail sticker to fit the shape of their own nails.

[0119] In addition, the nail sticker maintains its shape well even during the process of applying and curing the nail sticker, making it easy for users to use and allowing them to wear nail stickers that suit their nails better.

[0120] The deformation rate corresponds to a very low value compared to conventional UV-curable nail stickers. The inclusion of a soft layer in the nail sticker of this embodiment may be the main reason for such a low deformation rate.

[0121] More specifically, the deformation rate of the nail sticker may be 2.2% or less, more specifically, 0% to 2.2%, or 0% to 2.1% in an atmosphere at a temperature of 25° C. In addition to the use of a soft layer, the use of a process of applying heat after deforming the nail sticker into a nail shape during the manufacturing process of the nail sticker may be the main reason for such a lower deformation rate.

[0122] When the nail sticker is placed on a flat floor with the underside of the nail sticker before being hardened by ultraviolet light facing the flat floor, the deformation rate according to the following formula 1 in an atmosphere at a temperature of -10°C may be 0.2% or less, specifically 0% to 0.2%, more specifically 0% to 0.1%.

[0123] [Formula 1] Deformation ratio = [(BA) / A] x 100 In the formula 1, The A means the maximum width of the nail sticker measured immediately after the nail sticker is placed on the flat floor, and the B means the maximum width of the nail sticker measured one hour after the nail sticker is placed on the flat floor.

[0124] The nail sticker has a deformation rate of 0.2% or less according to the following formula 1 in an atmosphere at a temperature of -10°C, so the shape of the nail sticker can be maintained even at low temperatures (e.g., when stored in a cold place or in winter). Therefore, the shape of the nail sticker can be maintained to the maximum extent even during the process of delivering the product to the user.

[0125] When the nail sticker is placed on a flat floor with the underside of the nail sticker before being hardened by ultraviolet light facing the flat floor, the deformation rate according to the following formula 1 in an atmosphere at a temperature of 40°C may be 6% or less, specifically 4.5% or less, more specifically 0% to 4.3%, for example 0% to 3%.

[0126] [Formula 1] Deformation ratio = [(BA) / A] x 100 In the formula 1, The A means the maximum width of the nail sticker measured immediately after the nail sticker is placed on the flat floor, and the B means the maximum width of the nail sticker measured one hour after the nail sticker is placed on the flat floor.

[0127] The nail sticker has a deformation rate of 6% or less according to the following formula 1 in an atmosphere at a temperature of 40°C, so the shape of the nail sticker can be maintained even at high temperatures (e.g., when stored in a hot place or in summer). Therefore, the shape of the nail sticker can be maintained to the maximum extent even during the process of delivering the product to the user.

[0128] When the nail sticker is placed on a flat floor with the underside of the nail sticker before being hardened by ultraviolet light facing the flat floor, the deformation rate according to the following formula 1 in an atmosphere at a temperature of 60°C may be 8% or less, specifically 7% or less, more specifically 0% to 7%, for example 0% to 5%.

[0129] [Formula 1] Deformation ratio = [(BA) / A] x 100 In the formula 1, The A means the maximum width of the nail sticker measured immediately after the nail sticker is placed on the flat floor, and the B means the maximum width of the nail sticker measured one hour after the nail sticker is placed on the flat floor.

[0130] The nail sticker has a deformation rate of 6% or less according to the following formula 1 in an atmosphere at a temperature of 60°C, so the shape of the nail sticker can be maintained even at high temperatures (e.g., when stored in a hot place or in summer). Therefore, the shape of the nail sticker can be maintained to the maximum extent even during the process of supplying the product to the user.

[0131] When the nail sticker before being cured by ultraviolet light is placed on a flat floor and the area including the center of the top surface of the nail sticker is pressed with a force of 10 N using a push gauge from IMADA, the bottom surface of the center of the nail sticker can contact the floor. In other words, the nail sticker is not a hard molded product but is flexible, so it can be seen that it is a nail sticker (so-called gel nail sticker) that is easily deformed when external force is applied.

[0132] <Manufacturing method of nail stickers> A method for manufacturing a nail sticker according to another embodiment of the present invention includes a first step of placing a preliminary nail sticker that can be cured by ultraviolet light on a support included in a support structure; and a second step of applying pressure toward the upper surface of the preliminary nail sticker to bring the lower surface of the preliminary nail sticker into close contact with the upper surface of the support, wherein the support has a convex curved surface toward the top, and the lower surface of the nail sticker before being cured by ultraviolet light includes a curved surface that is curved so that the center of the nail sticker faces toward the top.

[0133] In the first step, the preliminary nail sticker 100' that can be cured by ultraviolet light may have a shape as shown in Fig. 5 before being placed on the support. That is, the preliminary nail sticker 100' may have a flat bottom surface or may have a curve, but the degree of curvature is not as severe as that of a regular nail.

[0134] That is, before the preliminary nail sticker 100' is placed on the support structure, when the nail sticker is placed on the flat floor so that the bottom surface of the preliminary nail sticker 100' before being cured by ultraviolet light faces the flat floor, the bottom surface of the preliminary nail sticker can be flat.

[0135] The preliminary nail sticker 100' may include a soft layer 110 and may further include a substrate layer 120. Alternatively, the preliminary nail sticker may include a soft layer 110, a substrate layer 120, and a coating layer 130. Here, the soft layer, the substrate layer, and the coating layer have the same configurations as those of the soft layer, the substrate layer, and the coating layer described as including the nail sticker of the above-mentioned embodiment, and therefore, the description thereof will be omitted.

[0136] 7, in the first step, a preliminary nail sticker 100' that can be cured by ultraviolet light (but has not yet been cured by ultraviolet light) can be placed on a support structure 200 including a support portion 210 having a convex curved surface toward the top. FIG. 6 is a schematic diagram of the support structure 200.

[0137] The support structure 200 may include one or more support parts 210, specifically, two or more support parts 210. The support part 210 may have a convex curved surface toward the top, specifically, the support part 210 may have a nail shape. The preliminary nail sticker 100' may be placed on the support part 210 so that the bottom surface of the preliminary nail sticker 100' is in contact with the top surface of the support part 210.

[0138] The material of the upper surface of the support may include at least one selected from the group consisting of polyethylene, polypropylene, and silicone, and more specifically may include polyethylene. Since the upper surface of the support includes polyethylene, the adhesive strength between the nail sticker and the support is not very strong, and therefore, unintended deformation of the nail sticker can be minimized when the nail sticker is separated from the support.

[0139] Referring to FIG. 8, in the second step, pressure is applied to the upper surface of the preliminary nail sticker to bring the lower surface of the preliminary nail sticker into close contact with the upper surface of the support.

[0140] Specifically, a pressure member having a nail-shaped recess can be used to apply pressure to the upper surface of the preliminary nail sticker, thereby making the preliminary nail sticker adhere to the support part 210 .

[0141] However, the present invention is not limited to this method, and other methods are also possible for adhering the preliminary nail sticker to the support part 210. The nail sticker 100 according to an embodiment of the present invention can be manufactured by the second step. That is, the lower surface of the nail sticker before being hardened by ultraviolet light may include a curved surface in which the center of the nail sticker is curved upward.

[0142] Referring to FIG. 9, the method for manufacturing the nail sticker may further include a third step of applying heat to the preliminary nail sticker 100' adhered to the support 210 after the second step.

[0143] This allows the nail sticker to more effectively maintain the nail shape (the lower surface of the nail sticker before being hardened by ultraviolet light includes a curved surface in which the center of the nail sticker is curved upward). The heat applied in the third step may be heat at a temperature of 30°C to 70°C, specifically, heat at a temperature of 45°C to 55°C. When this range is satisfied, the effect of significantly reducing the degree of change in shape of the product during storage while maintaining flexibility is achieved.

[0144] The heat can be applied for 20 seconds to 3 minutes, specifically 30 seconds to 2 minutes. The heat can be applied by applying hot air or near infrared rays.

[0145] <Nail sticker set> A nail sticker set according to another embodiment of the present invention includes a support structure including a support portion; and a nail sticker attached to an upper surface of the support portion; wherein the upper surface of the support portion includes a curved surface that is curved so that the center of the sticker faces upward, the nail sticker is curable by ultraviolet light, and an outer surface of the nail sticker before being cured by ultraviolet light includes a curved surface that is curved so that the center of the nail sticker faces upward.

[0146] Here, since the nail sticker is the same as the nail sticker of the above-described embodiment, the physical properties of the nail sticker of the above-described embodiment may be the same as the physical properties of the nail sticker (the nail sticker peeled off from the support structure) referred to in this embodiment. Also, referring to Fig. 10, the support structure 200 may be the same as the support structure described in the other embodiment.

[0147] 10, in the nail sticker set 300, the nail sticker 100 is disposed on the support part 210. The nail sticker 100 and the support part 210 may both have a nail shape and may overlap each other. That is, the lower surface of the nail sticker before being cured by ultraviolet light may have a curved surface in which the center of the nail sticker is curved upward, and the support part may also have the same shape.

[0148] 11 and 12 are photographs of a nail sticker set according to an embodiment of the present invention. More than 50%, specifically more than 70%, more specifically 90% to 100%, for example 95% to 100%, of the bottom surface of the nail sticker may be in contact with the top surface of the support. This means that the nail sticker described in the present invention can effectively maintain the nail shape, minimizing the separation of the bottom surface of the nail sticker from the support structure during delivery of the nail sticker to the user.

[0149] When the nail sticker is peeled off from the support and placed on a flat floor with the underside of the nail sticker before being cured by ultraviolet light facing the flat floor, the center of the nail sticker may be spaced apart from the floor, thereby allowing a user to more easily shape the nail sticker to fit the shape of their own nails.

[0150] In addition, the nail sticker maintains its shape well even during the process of application and hardening, making it easy for users to use and allowing them to wear nail stickers that better fit their nails.

[0151] When the nail sticker is peeled off from the support and placed on a flat floor with the underside of the nail sticker before being hardened by ultraviolet rays facing the flat floor, the deformation rate according to the following formula 1 in an atmosphere at a temperature of 25°C may be 4% or less, specifically 0% to 3%, more specifically 0% to 2.1%.

[0152] [Formula 1] Deformation ratio = [(BA) / A] x 100 In the formula 1, The A means the maximum width of the nail sticker measured immediately after the nail sticker is placed on the flat floor, and the B means the maximum horizontal length of the nail sticker measured one hour after the nail sticker is placed on the flat floor.

[0153] The nail sticker has a deformation rate of 4% or less according to the following formula 1 in an atmosphere at a temperature of 25°C, so the shape of the nail sticker can be maintained to the maximum extent even during the process of supplying the product to the user. Also, the user can more easily shape the nail sticker to fit the shape of their own nails. Furthermore, the formed nail sticker can well maintain its shape even during the process of applying and curing the nail sticker, so the user can use it easily and wear the nail sticker that fits their nails better.

[0154] The material of the upper surface of the support may include at least one selected from the group consisting of polyethylene, polypropylene, and silicone, and more specifically may include polyethylene. Since the upper surface of the support includes polyethylene, the adhesive strength between the nail sticker and the support is not very strong, and therefore, unintended deformation of the nail sticker can be minimized when the nail sticker is separated from the support.

[0155] The support structure may include one or more, specifically two or more, support portions, and the nail sticker set may include one or more, specifically two or more nail stickers.

[0156] Below, preferred examples are presented to help understand the present invention. However, the above examples are merely illustrative of the present description, and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope of the scope and technical ideas of the present description. It is natural that such changes and modifications fall within the scope of the appended claims.

[0157] <Examples and Comparative Examples> Example 1 (1) Prepare spare nail stickers A nail sticker was prepared, which included a base layer (maximum thickness: 150 μm) including an adhesive layer and a design layer, a soft layer (maximum thickness: 2000 μm) disposed on the base layer, and a coating layer (maximum thickness: 65 μm) disposed on the soft layer.

[0158] The soft layer contains 60% by weight of cellulose acetate butyrate, which is a resin for the soft layer, 38% by weight of urethane acrylate oligomer, which is a UV-curable raw material for the soft layer, and 2% by weight of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, which is a photoinitiator for the soft layer.

[0159] The coating layer includes urethane acrylate, which is an ultraviolet curing raw material for the coating layer, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, which is a photoinitiator for the coating layer, and nitrocellulose, which is a resin for the coating layer.

[0160] (2) Forming preliminary nail stickers A support structure including a support part with a convex upper surface like the upper surface of a nail was prepared. The preliminary nail sticker was placed on the upper surface of the support part. At this time, the adhesive layer on the lower surface of the preliminary nail sticker was in contact with the upper surface of the support part.

[0161] Then, pressure was applied to the upper surface of the preliminary nail sticker so that the lower surface of the preliminary nail sticker was in close contact with the upper surface of the support part included in the support structure, and thus the preliminary nail sticker supported by the support part had a curved shape with the center pointing upward like a nail.

[0162] The preliminary nail sticker placed on the support structure was irradiated with near-infrared light and heated at 50°C for 2 minutes to produce a nail sticker set including the nail sticker and the support structure. No UV curing step was performed during the manufacturing process.

[0163] Example 2 (1) Prepare spare nail stickers A nail sticker was prepared, which included a base layer (maximum thickness: 150 μm) including an adhesive layer and a design layer, a soft layer (maximum thickness: 2000 μm) disposed on the base layer, and a coating layer (maximum thickness: 65 μm) disposed on the soft layer.

[0164] The soft layer contains 60% by weight of cellulose acetate butyrate, which is a resin for the soft layer, 38% by weight of urethane acrylate oligomer, which is a UV-curable raw material for the soft layer, and 2% by weight of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, which is a photoinitiator for the soft layer.

[0165] The coating layer includes urethane acrylate, which is an ultraviolet curing raw material for the coating layer, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, which is a photoinitiator for the coating layer, and nitrocellulose, which is a resin for the coating layer.

[0166] (2) Forming preliminary nail stickers Meanwhile, a support structure including a support part with a convex upper surface like the upper surface of a nail was prepared. The spare nail sticker was placed on the upper surface of the support part. At this time, pressure was applied to the upper surface of the spare nail sticker so that the adhesive layer on the lower surface of the spare nail sticker contacted the upper surface of the support part. As a result, the spare nail sticker supported by the support part had a curved shape with the center pointing upward like a nail.

[0167] The preliminary nail sticker supported by the support was left at room temperature for 2 hours to prepare a nail sticker set including the nail sticker and the support structure. No UV curing process was performed during the manufacturing process.

[0168] Comparative Example 1 (1) Prepare spare nail stickers A nail sticker was prepared, which included a base layer (maximum thickness: 150 μm) including an adhesive layer and a design layer, a first coating layer (maximum thickness: 2000 μm) disposed on the base layer, and a second coating layer (maximum thickness: 65 μm) disposed on the first coating layer.

[0169] The first coating layer contains 60% by weight of nitrocellulose, which is a resin for the first coating layer, 38% by weight of urethane acrylate oligomer, which is a UV-curable raw material for the first coating layer, and 2% by weight of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, which is a photoinitiator for the first coating layer.

[0170] The second coating layer includes urethane acrylate, which is an ultraviolet curing raw material for the second coating layer, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, which is a photoinitiator for the second coating layer, and nitrocellulose, which is a resin for the second coating layer.

[0171] (2) Forming preliminary nail stickers Meanwhile, a support structure including a support portion having a convex upper surface in the center like the upper surface of a nail was prepared. The spare nail sticker was placed on the upper surface of the support portion. At this time, the adhesive layer on the lower surface of the spare nail sticker was in contact with the upper surface of the support portion. Then, an external force was applied to the upper surface of the spare nail sticker so that the lower surface of the spare nail sticker was in close contact with the upper surface of the support portion included in the support structure. As a result, the spare nail sticker supported by the support portion had a curved shape with the center pointing upward like a nail.

[0172] The preliminary nail sticker supported by the support portion was left at room temperature for 2 hours to prepare a nail sticker set including the nail sticker and the support structure.

[0173] There was no UV curing step during the manufacturing process.

[0174] Experimental Example 1: Evaluation of whether the shape is maintained and the deformation rate (1) Evaluation at 25°C Immediately after separating the nail sticker of Example 1 from the support, the nail sticker (not cured by UV light) was placed on a flat floor. Specifically, when the uncured nail sticker was placed on the flat floor with the underside of the uncured nail sticker facing downward, the center of the nail sticker was separated from the floor and maintained a curved shape with the center facing upward.

[0175] Specific results are shown in Table 1 and FIGS.

[0176] Fig. 13 is a photograph of the nail sticker of Example 1 immediately after production, Fig. 14 is a photograph of the nail sticker of Example 1 after being left for 24 hours, Fig. 15 is a photograph of the nail sticker of Example 2 immediately after production, Fig. 16 is a photograph of the nail sticker of Example 2 after being left for 24 hours, Fig. 17 is a photograph of the nail sticker of Comparative Example 1 immediately after production, Fig. 18 is a photograph of the nail sticker of Comparative Example 1 after being left for 24 hours.

[0177] It can be seen that the nail stickers of Examples 1 and 2 maintained their shape even after 24 hours, but the nail sticker of Comparative Example 1 was unable to maintain its shape after 24 hours.

[0178] (2) Evaluation at -10℃, 40℃, and 60℃ The same experiment as above was carried out at −10° C., 40° C. and 60° C., and the results are shown in Table 1.

[0179] [Table 1]

[0180] The "shape retention" refers to whether the nail sticker maintains its curved shape with the center pointing upward (whether the center of the bottom surface of the nail sticker maintains its position away from the floor) when placed on a flat floor and left for 24 hours. In other words, it indicates whether the curved shape is maintained during the process of delivery to consumers (O if maintained, X if not). The deformation rate was calculated using the following formula 1.

[0181] [Formula 1] Deformation ratio = [(BA) / A] x 100 In Equation 1 and Table 1, the A value is the maximum width of the nail sticker measured immediately after the nail sticker is placed on the flat floor, and the B value is the maximum width of the nail sticker measured after the nail sticker is left on the flat floor for 1 hour. [Explanation of symbols]

[0182] 100: Nail stickers 110: Soft layer 120: Base material layer 130: Coating layer 200: Support structure 210: Support part 300: Nail sticker set

Claims

1. A nail sticker that can be cured by ultraviolet light, The nail sticker includes a soft layer, a substrate layer, and a coating layer, The soft layer is disposed on the substrate layer, and the coating layer is disposed on the soft layer. The soft layer includes a soft layer resin, a soft layer ultraviolet curing material, and a soft layer photoinitiator, the resin for the soft layer contains at least one of cellulose acetate butyrate and cellulose acetate propionate; the photoinitiator for the soft layer includes at least one selected from the group consisting of trimethylbenzoyl phosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone; The ultraviolet curing raw material for the soft layer is contained in the soft layer in an amount of 30% by weight to 65% by weight, The photoinitiator for the soft layer is contained in the soft layer in an amount of 2% by weight to 7% by weight, The lower surface of the nail sticker before being cured by ultraviolet light includes a curved surface that is curved such that the center of the nail sticker faces upward, When the nail sticker is placed on a flat floor with the bottom surface of the nail sticker facing the flat floor before being cured by ultraviolet light, the deformation rate according to the following formula 1 is 4% or less in an atmosphere at a temperature of 25°C. Nail stickers. [Formula 1] Deformation ratio = [(B - A) / A] x 100 In the formula 1, The A means the maximum width of the nail sticker measured immediately after the nail sticker is placed on the flat floor, The value B means the maximum width of the nail sticker measured one hour after the nail sticker was placed on the flat floor.

2. When the nail sticker is placed on a flat floor with the lower surface of the nail sticker before being cured by ultraviolet light facing the flat floor, the center of the nail sticker is spaced apart from the floor. The nail sticker according to claim 1 .

3. When the nail sticker is placed on a flat floor with the bottom surface of the nail sticker facing the flat floor before being cured by ultraviolet light, the deformation rate according to the following formula 1 is 0.2% or less in an atmosphere at a temperature of -10°C. The nail sticker according to claim 1 . [Formula 1] Deformation ratio = [(B - A) / A] x 100 In the formula 1, The A means the maximum width of the nail sticker measured immediately after the nail sticker is placed on the flat floor, The value B means the maximum width of the nail sticker measured one hour after the nail sticker is placed on the flat floor.

4. When the nail sticker is placed on a flat floor with the bottom surface of the nail sticker facing the flat floor before being cured by ultraviolet light, the deformation rate according to the following formula 1 is 6% or less in an atmosphere at a temperature of 40°C. The nail sticker according to claim 1 . [Formula 1] Deformation ratio = [(B - A) / A] x 100 In the formula 1, The A means the maximum width of the nail sticker measured immediately after the nail sticker is placed on the flat floor, The value B means the maximum width of the nail sticker measured one hour after the nail sticker is placed on the flat floor.

5. The nail sticker includes at least one coating layer, The coating layer includes an ultraviolet curing material. The nail sticker according to claim 1 .

6. The nail sticker includes a substrate layer, The substrate layer includes an adhesive layer. The nail sticker according to claim 1 .

7. The adhesive layer is located under the nail sticker and constitutes at least a part of the lower surface of the nail sticker. The nail sticker according to claim 1 .

8. When the nail sticker before being cured by ultraviolet light is placed on a flat floor and the upper surface of the nail sticker is pressed with a force of 10 N using a PUSH GAGE ​​device manufactured by IMADA, the lower surface of the center of the nail sticker comes into contact with the floor. The nail sticker according to claim 1 .

9. When the nail sticker is placed on a flat floor with the lower surface of the nail sticker before being hardened by ultraviolet light facing the flat floor, at least a part of the edge of the nail sticker comes into contact with the flat floor. The nail sticker according to claim 1 .

10. a support structure including a support portion; The nail sticker according to claim 1 attached to the upper surface of the support part, The upper surface of the support portion includes a curved surface that is curved so that the center of the nail sticker faces upward, The nail sticker is curable by ultraviolet light; The lower surface of the nail sticker before being cured by ultraviolet light includes a curved surface that is curved so that the center of the nail sticker faces upward. Nail sticker set.

11. 50% or more of the lower surface of the nail sticker is in contact with the upper surface of the support part. The nail sticker set according to claim 10.

12. When the nail sticker is peeled off from the support and placed on a flat floor with the underside of the nail sticker before being hardened by ultraviolet light facing the flat floor, the center of the nail sticker is spaced apart from the floor. The nail sticker set according to claim 10.

13. When the nail sticker is peeled off from the support and placed on a flat floor with the underside of the nail sticker before being cured by ultraviolet light facing the flat floor, the deformation rate according to the following formula 1 is 4% or less in an atmosphere at a temperature of 25°C. The nail sticker set according to claim 10. [Formula 1] Deformation ratio = [(B - A) / A] x 100 In the formula 1, The A means the maximum width of the nail sticker measured immediately after the nail sticker is placed on the flat floor, The value B means the maximum width of the nail sticker measured one hour after the nail sticker is placed on the flat floor.

14. The material of the upper surface of the support portion includes at least one selected from the group consisting of polyethylene, polypropylene, and silicone. The nail sticker set according to claim 10.

15. the support structure includes two or more supports; The nail sticker set includes two or more nail stickers. The nail sticker set according to claim 10.

Images