nail stickers

Abstract

The present invention relates to a nail sticker, the nail sticker being a hardenable nail sticker, the nail sticker including a soft layer, the soft layer including a resin for the soft layer, and the resin for the soft layer including at least one of cellulose acetate butyrate and cellulose acetate propionate.

Description

[Technical Field]

[0001] The present invention relates to a hardenable nail sticker that includes a soft layer. [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 products, nail stickers in the shape of artificial fingernails or toenails are widely used. Previously, nail stickers were manufactured and supplied to consumers with curved shapes that resembled fingernails or toenails. However, because the shape (especially the curvature) of each person's fingernails or toenails varies, there was a problem in that nail stickers with a curved shape did not adhere closely to the consumer's fingernails or toenails.

[0005] To solve this problem, nail stickers containing UV-curable materials have recently gained popularity. Specifically, consumers modify the nail sticker to fit their fingernails or toenails and then cure the nail sticker by irradiating it with UV light. This allows the nail sticker to adhere closely to the consumer's fingernails or toenails, improving the adhesive strength of the nail sticker. Such nail stickers are also called gel nail stickers.

[0006] In addition, in the process of using the UV-curable nail sticker, the form in which the nail sticker is attached may change depending on the shape of the consumer's fingernail or toenail. However, referring to FIG. 1, if the fingernail or toenail 2 on the finger 3 is curved (with a small, sharp curve), the nail sticker will be firmly attached to the fingernail or toenail in the region 2a near the cuticle on the top surface of the fingernail or toenail, but the nail sticker may not be attached to the fingernail or toenail in the region near the tip of the fingernail or toenail (region 2b near the free edge), resulting in a floating phenomenon (e).

[0007] If the nail sticker is not smoothly attached to the fingernail or toenail and the nail sticker floats, foreign matter is likely to be located in the floating area, contaminating the nail sticker, causing a foreign body sensation to the consumer, and reducing the adhesive strength of the nail sticker.

[0008] In addition, in some cases, as shown in FIG. 2, when the nail sticker is applied to the fingernail and then cured, the nail sticker may bend excessively (f), which may cause a problem of damaging the appearance of the nail sticker.

[0009] Furthermore, if the surface of the fingernail or toenail is excessively uneven, as shown in Figure 3, when applying the nail sticker, the surface of the nail sticker will also become excessively uneven along with the surface of the fingernail or toenail.

[0010] Therefore, there is a need for a new nail sticker that can minimize the lifting phenomenon of the nail sticker and make the surface of the nail sticker smooth. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Republic of Korea Patent Publication No. 10-2019-0014044 Summary of the Invention [Problem to be solved by the invention]

[0012] One problem that the present invention aims to solve is to provide a nail sticker that minimizes the floating phenomenon between the nail sticker and the fingernail (or toenail), minimizes contamination of the nail sticker, and makes it less likely for the user to feel a foreign body sensation.

[0013] Another object of the present invention is to provide a nail sticker that can minimize excessive deformation of the shape of the nail sticker.

[0014] Another problem to be solved by the present invention is to provide a nail sticker that can have a smooth surface even if the surface of the fingernail or toenail is uneven. [Means for solving the problem]

[0015] According to one embodiment of the present invention, there is provided a curable nail sticker, the nail sticker including a soft layer, the soft layer including a resin for the soft layer, and the resin for the soft layer including at least one of cellulose acetate butyrate and cellulose acetate propionate.

[0016] According to another embodiment of the present invention, there is provided a hardenable nail sticker, the nail sticker including a soft layer, and when the nail sticker is attached to a flat floor and pressure is applied to a portion of the upper surface of the nail sticker, the maximum thickness of the soft layer increases.

[0017] According to yet another embodiment of the present invention, there is provided a hardenable nail sticker, the nail sticker including a soft layer, and when the nail sticker is attached to a flat floor and pressure is applied to a portion of the upper surface of the nail sticker, the maximum thickness of the nail sticker increases.

[0018] According to another embodiment of the present invention, there is provided a curable nail sticker, the nail sticker including a soft layer, which is prepared by preparing a rectangular parallelepiped substrate having a thickness of 0.7 mm and placed on a flat floor, and attaching the nail sticker to the upper surface of the substrate so that an area having a length equivalent to 70% of the total length of the nail sticker is in contact with the flat upper surface of the substrate, and applying a force of 38.5 N in the direction of the floor to at least a part of the upper surface of the part of the nail sticker that overlaps the substrate in the vertical direction in an atmosphere of 36°C, and then removing the force and leaving it at 36°C for 30 minutes, and then measuring the nail sticker, the shortest distance between the area of ​​the part of the nail sticker that does not overlap the substrate in the vertical direction and protruding from the substrate and that contacts the floor and the substrate is 1.5 mm or less, and the force is applied to an area equivalent to 40% to 80% of the total area of ​​the upper surface of the nail sticker. [Effects of the Invention]

[0019] According to the present invention, the thickness of the soft layer adjacent to the tip of the nail (fingernail or toenail) can be increased during the process of the user applying the nail sticker. As a result, the soft layer can effectively fill the space between the nail sticker and the nail (fingernail or toenail), minimizing the lifting phenomenon of the nail sticker. This can reduce contamination of the nail sticker by foreign matter, alleviate the foreign body sensation felt by the user, and further improve the adhesive strength of the nail sticker.

[0020] In addition, the soft layer can prevent the nail sticker from being excessively deformed.

[0021] Furthermore, even if the surface of the fingernail or toenail is uneven, the surface of the applied nail sticker can have a smooth shape, thereby improving aesthetics. [Brief explanation of the drawings]

[0022] [Figure 1]1 is a cross-sectional view showing a conventional nail sticker attached to a nail. [Figure 2] 1 is a cross-sectional view showing a conventional nail sticker attached to a nail. [Figure 3] 1 is a cross-sectional view showing a conventional nail sticker attached to a nail. [Figure 4] 1 is a plan view (top view) of a nail sticker according to an embodiment of the present invention. [Figure 5] 1 is a cross-sectional view of a portion of a nail sticker according to an embodiment of the present invention. [Figure 6] 1 is a cross-sectional view of a portion of a nail sticker according to an embodiment of the present invention. [Figure 7] 1 is a cross-sectional view of a nail sticker according to an embodiment of the present invention placed on a flat floor. [Figure 8] 1 is a cross-sectional view of a nail sticker according to an embodiment of the present invention when pressure is applied thereto. [Figure 9] 10 is a cross-sectional view showing a state where pressure is applied to a nail sticker according to an embodiment of the present invention, the pressure is removed, and the sticker is left for 30 minutes. [Figure 10] 4 is a cross-sectional view illustrating a state in which pressure is applied to a nail sticker according to an embodiment of the present invention after the nail sticker is attached to a nail. [Figure 11] 4 is a cross-sectional view illustrating a state in which pressure is applied to a nail sticker according to an embodiment of the present invention after the nail sticker is attached to a nail. [Figure 12] 1 is a cross-sectional view illustrating physical properties of a nail sticker according to an embodiment of the present invention. [Figure 13] This is a photograph of the nail sticker of Example 1 when it is not attached to the nail (no pressure is being applied). [Figure 14] This is a photograph of the nail sticker of Example 1 after pressure has been applied for several seconds, the pressure has been removed, and the sticker has been left for a certain period of time. [Figure 15]This is a photograph of the nail sticker of Comparative Example 1 when it is not attached to the nail (no pressure is being applied). [Figure 16] This is a photograph of the nail sticker of Comparative Example 1 after pressure has been applied for several seconds, the pressure has been removed, and the sticker has been left for a certain period of time. [Figure 17] 1 is a photograph showing the nail sticker according to Example 1 worn on nails. [Figure 18] 1 is a photograph of a nail sticker according to Comparative Example 1 worn on a nail. [Figure 19] 1 is a photograph showing a cross section of a nail sticker after the nail sticker according to Example 1 is applied to a nail. [Figure 20] 1 is a photograph showing a cross section of a nail sticker according to Comparative Example 1 after the nail sticker is applied to a nail. [Figure 21] 1 is a photograph showing the underside of a nail sticker according to Example 1 after the sticker has been applied to a nail and then peeled off. [Figure 22] 1 is a photograph of the underside of a nail sticker according to Comparative Example 1 after it has been applied to a nail and then peeled off. [Figure 23] This is a photo of a nail with severe curvature on the surface. [Figure 24] 24 is a photograph showing the nail sticker according to Example 1 being worn on the nail of FIG. 23. [Figure 25] 24 is a photograph showing the nail sticker according to Comparative Example 1 worn on the nail of FIG. 23. [Figure 26] 24 is a photograph of the underside of the nail sticker after the nail sticker according to Example 1 has been applied to the nail of FIG. 23 and then peeled off. [Figure 27] 24 is a photograph of the underside of the nail sticker according to Comparative Example 1 after it has been applied to the nail of FIG. 23 and then peeled off. [Figure 28] 1 is a cross-sectional photograph showing how the nail sticker of Example 1 is deformed by external pressure. [Figure 29] 1 is a cross-sectional photograph showing how the nail sticker of Comparative Example 1 is deformed by external pressure. [Figure 30] 10A and 10B are diagrams illustrating how pressure is applied to a nail sticker according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Because the present invention is susceptible to various modifications and embodiments, specific embodiments are shown by way of example in the drawings and will be described in detail in the detailed description.

[0024] However, it should be understood that this is not intended to limit the present invention to the specific embodiments, 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 a detailed description of related publicly known technology is considered to obscure the gist of the present invention, the detailed description will be omitted.

[0025] 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 the context clearly indicates otherwise.

[0026] 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 in the specification, 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.

[0027] 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.

[0028] By nail herein is meant fingernails and / or toenails.

[0029] The thickness measured in the present invention can be confirmed through a Keyence VHX-970F device.

[0030] As used herein, the "maximum thickness" of a certain structure refers to the greatest thickness of the structure measured vertically from any fulcrum on the underside of the structure. The fulcrum at which the maximum thickness is exhibited before pressure is applied may be the same as or different from the fulcrum at which the maximum thickness is exhibited after pressure is applied and then removed.

[0031] The upper surface of the nail sticker in this specification refers to the surface exposed toward the upper direction when the R direction in Figures 7 to 11 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 where the R' direction in Figures 7 to 11 is the lower direction when the R' direction 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.

[0032] 4, the nail sticker can include a long axis and a short axis. The long axis corresponds to the 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 (AA' in FIG. 4).

[0033] Here, the length (100L) of the nail sticker means 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 worn on the nail, and the longitudinal direction of the nail sticker is parallel to the long axis.

[0034] The minor axis is an imaginary line segment perpendicular to the major axis (BB' in FIG. 4), and the width (100W) of the nail sticker is parallel to the minor axis of the nail sticker. The center 100a of the nail sticker is the fulcrum where the longest part of the length of the nail sticker is divided into two equal parts.

[0035] In this specification, "applying pressure" to describe the physical properties of the nail sticker means applying a force of 38.5 N to the upper surface of the nail sticker at a temperature of 36°C. The pressure can be applied using a push gage device manufactured by IMADA, and the pressure value can be measured. The lower surface area of ​​the pressure applying member is, for example, 177 mm 2 It may be, but is not limited to this.

[0036] In addition, the pressure is not applied to 1) the fulcrum where the thickness of the soft layer is greatest before the pressure is applied, and 2) the fulcrum where the thickness of the nail sticker is greatest before the pressure is applied. Specifically, the pressure may be applied by applying a force of 38.5 N downward to an area equivalent to 40% to 80% of the total area of ​​the upper surface of the nail sticker in a temperature atmosphere of 36°C.

[0037] <Nail stickers> The nail sticker refers to an artificial laminated structure manufactured for application to nails (fingernails and / or toenails). Considering its application as an application, it is also called nail art or nail art sticker. Specifically, when a consumer receives the nail sticker, the consumer applies the nail art to the nail while deforming the shape of the nail sticker so that the nail sticker adheres to the nail, and then irradiates the nail sticker with ultraviolet light to harden it.

[0038] A nail sticker according to an embodiment of the present invention includes a hardenable soft layer, the soft layer includes a soft layer resin, and the soft layer resin may include at least one of cellulose acetate butyrate and cellulose acetate propionate.

[0039] When using a conventional curable nail sticker, if the nail is bent in a sharp curve (small radius of curvature), the nail sticker adheres firmly to the nail in the area of ​​the upper surface of the nail close to the cuticle, but the nail sticker does not adhere to the nail in the area near the end of the nail (area close to the free edge), which can cause a floating phenomenon. If the nail sticker does not adhere smoothly to the nail and the nail sticker floats, foreign matter is likely to be located in the floating area, contaminating the nail sticker, causing a foreign body sensation to the consumer, and reducing the adhesive strength of the nail sticker.

[0040] To solve these problems, researchers have worked hard to incorporate a soft layer into nail stickers. Because the soft layer has appropriate storage and loss moduli at body temperature, when a user applies a certain amount of force while applying the nail sticker, the soft layer is easily deformed by body temperature and can maintain the deformed shape, so the soft layer can fill the floating space between the nail (or toenail) and the nail sticker and maintain the filled state.

[0041] This reduces contamination of the nail sticker by foreign matter, alleviating the feeling of foreign matter felt by the user, and further improving the adhesive strength of the nail sticker. Furthermore, when a portion of the nail sticker extends beyond the nail area, the soft layer can support the extended and protruding portion of the nail sticker so that it does not deform. Furthermore, even if the nail surface is uneven, the surface of the applied nail sticker can have a smooth shape, thereby improving aesthetics.

[0042] This will be explained in more detail below.

[0043] The soft layer may contain a resin for the soft layer, which may contain at least one of cellulose acetate butyrate and cellulose acetate propionate.

[0044] As a result, when a user applies a certain amount of force while applying the nail sticker, the soft layer fills the gaps between the nails, effectively maintaining the filled shape, thereby reducing the foreign body sensation felt by the user and increasing the adhesive strength of the nail sticker.

[0045] Furthermore, when a portion of the nail sticker extends beyond the nail area, the soft layer can support the extended and protruding portion of the nail sticker so that it is not deformed.

[0046] In addition, even if the nail surface is uneven, a certain force can be applied to deform the nail so that a larger amount of the soft layer is disposed on the concave portions of the nail surface. As a result, even if the nail surface is uneven, the surface of the applied nail sticker can have a smooth shape, thereby improving aesthetics. Furthermore, the cellulose acetate butyrate and the cellulose acetate propionate have the advantage of superior shock absorption compared to other materials.

[0047] More specifically, the resin for the soft layer may include cellulose acetate butyrate, for example, which has excellent impact absorption capacity and durability, and when mixed with the UV-curable raw material for the soft layer, increases ductility, and deformation of the soft layer due to external impact is irreversible due to the effect of impact absorption capacity, and once deformed, the shape can be more easily maintained.

[0048] 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, more specifically 30 to 65% by weight. When the content is within this range, the soft layer is easily deformed at body temperature and can maintain the deformed shape of the soft layer.

[0049] 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.

[0050] 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.

[0051] Specifically, the UV-curable raw material for the soft layer may include at least one of a urethane acrylate oligomer, a polyester acrylate oligomer, and an epoxy acrylate oligomer.

[0052] The urethane acrylate oligomer is advantageous because it can be easily cured by ultraviolet light and has a predetermined flexibility even after curing.

[0053] In addition, the haze phenomenon can be minimized, 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.

[0054] 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.

[0055] The epoxy acrylate oligomer has high reactivity, good hardness and abrasiveness, is easily cured, has excellent flexibility, and can be stably cured 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 greater the rigidity or thermal stability.

[0056] 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.

[0057] The polyester acrylate oligomer has excellent reactivity and superior adhesive strength to urethane acrylate oligomers and epoxy acrylate oligomers. The polyester acrylate oligomer may be an oligomer having four or six functional groups.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] When the composition satisfies the above criteria, 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.

[0062] 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.

[0063] 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.

[0064] In the soft layer, the weight ratio of the UV-curable soft layer raw material to the resin for the soft layer 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 resin for the soft layer and the viscosity of the UV-curable soft layer raw material are combined, resulting in an increased ability to absorb external impact energy.

[0065] 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.

[0066] The photoinitiator for the soft layer may have an absorption wavelength band in the range of 200 nm to 600 nm.

[0067] 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.

[0068] 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.

[0069] The maximum thickness of the soft layer may be 250 μm to 2500 μm, specifically 500 μm to 2400 μm, more specifically 600 μm to 2000 μm, for example, 1000 μm to 2000 μm.

[0070] When the above range is satisfied, a sufficient portion of the soft layer can be moved to minimize the lifting phenomenon 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 does not deform. Furthermore, even if the nail surface is uneven, the movement of the soft layer allows a larger amount of the soft layer to be positioned sufficiently on the concave portion of the nail, so that the surface of the applied nail sticker can have a smoother shape.

[0071] In addition, since the soft layer may not have a high rate of deformation 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.

[0072] The soft layer may be a single layer, or alternatively, may be made up of two or more layers.

[0073] The nail sticker may further include a base layer, and the soft layer may be disposed on the base layer.

[0074] 5 to 11, the upper surface of the base layer 120 and the lower surface of the soft layer 110 may face each other, specifically, may be in contact with each other. That is, the soft layer 110 may be positioned on the base layer 120.

[0075] The base layer may include an adhesive layer. The adhesive layer provides chemical adhesion that allows the nail sticker to be attached to a nail. As a result, the adhesive layer may constitute the bottom surface of the nail sticker. The outer surface of the nail sticker of the present invention may be flat, which may mean that the bottom surface of the adhesive layer is flat. The adhesive layer includes an adhesive component, which may correspond to an adhesive component commonly used in the art.

[0076] 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 a pattern, various materials for aesthetic purposes, such as mica, etc.

[0077] 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 corresponds to a component that is removed when the nail sticker is used. The base film may include components commonly used in the art.

[0078] The nail sticker may further include a coating layer.

[0079] 5 to 11, in the nail sticker 100, the coating layer 130 may be located on the soft layer 110.

[0080] The coating layer may include an ultraviolet curable material for the coating layer and a resin for the coating layer.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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 the higher the number of functional groups, the better the rigidity or thermal stability.

[0088] 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.

[0089] The polyester acrylate oligomer has excellent reactivity and superior adhesive strength to urethane acrylate oligomers and epoxy acrylate oligomers. The polyester acrylate oligomer may be an oligomer having four or six functional groups.

[0090] 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, which are products of Miwon.

[0091] 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.

[0092] In the coating 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 coating 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 this composition is satisfied, 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 applied.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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 can be properly 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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 can be formed into a round shape.

[0101] Meanwhile, the resin for the coating layer may include a thermosetting resin for the coating layer and a thermal initiator.

[0102] The coating layer may further include a photoinitiator for the coating layer.

[0103] The photoinitiator serves to initiate a polymerization reaction upon irradiation with ultraviolet light, and specifically, the photoinitiator may be an ultraviolet photoinitiator.

[0104] The photoinitiator may have an absorption wavelength band in the range of 200 nm to 600 nm.

[0105] 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.

[0106] 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 this range is satisfied, the coating layer can have an appropriate hardness when cured by a user.

[0107] 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 solvent may remain in the coating layer.

[0108] The nail sticker may further include a design expression layer disposed on the coating layer, which may express a matte finish or a thick film-type three-dimensional figure such as a three-dimensional line, a cone, or a circular dome.

[0109] The maximum thickness of the nail sticker may be 300 μm to 3,000 μm, specifically 600 μm to 2,800 μm, more specifically 700 μm to 2,600 μm. When the thickness is within this range, a significant soft layer effect is obtained.

[0110] A nail sticker according to another embodiment of the present invention is a hardenable sticker, and the nail sticker includes a soft layer, and when the nail sticker is placed on a flat floor and pressure is applied to a portion of the upper surface of the nail sticker, the maximum thickness of the soft layer can be increased.

[0111] Here, the nail sticker may be the same as the nail sticker described above. The soft layer, coating layer, base layer, etc. of the nail sticker described above may also be included in the nail sticker of this embodiment.

[0112] The application of pressure means applying a force of 38.5 N to the upper surface of the nail sticker in an atmosphere having a temperature of 36°C.

[0113] The pressure can be applied via a push gage device manufactured by IMADA, and the pressure value can be measured. The lower surface area of ​​the pressure applying member is, for example, 177 mm 2 It may be, but is not limited to this.

[0114] In addition, pressure is not applied to 1) the fulcrum where the thickness of the soft layer is greatest before pressure is applied, and 2) the fulcrum where the thickness of the nail sticker is greatest before pressure is applied.

[0115] Specifically, the application of pressure may involve applying a force of 38.5 N downward to an area equivalent to 40% to 80% of the total area of ​​the top surface of the nail sticker in a temperature atmosphere of 36°C.

[0116] FIG. 8 is a diagram illustrating the application of pressure, and FIG. 30 is a top view of the lower surface of the pressure applying member coming into contact with the upper surface of the nail sticker.

[0117] 8 and 30, the pressure is not directly applied to the fulcrum where the maximum thickness (A1) of the soft layer 110 exists and the fulcrum where the maximum thickness (A2) of the nail sticker 100 exists. That is, the pressure is applied to a portion (Q) of the upper surface of the nail sticker, and the portion (Q) of the upper surface does not include the fulcrum where the maximum thickness of the nail sticker exists and the fulcrum where the maximum thickness of the nail sticker exists.

[0118] More specifically, the nail sticker 100 is placed on a flat floor (F1). The nail sticker 100 may have an asymmetric structure in the longitudinal direction. That is, the thickness of the nail sticker 100 may be asymmetric in the longitudinal direction.

[0119] When pressure is applied, the lower surface (Ps) of the member (P) applying the pressure comes into contact with the area corresponding to 100b in FIG.

[0120] For example, pressure is applied to the pressure applying member (P) from one end (100g) of the nail sticker 100 (the end facing the cuticle of the nail when the nail sticker is attached) to a fulcrum that is a distance equivalent to 70% of the length (100L) of the nail sticker 100 from the one end (the area corresponding to 100b in Figure 8).

[0121] 30, the area where the lower surface (Ps) of the pressure applying member (P) and the upper surface of the nail sticker 100 intersect can be formed in a direction starting from a fulcrum that is a distance equivalent to 70% of the length (100L) of the nail sticker 100 from one end (100g) of the nail sticker and moving toward the one end (100g). The other end (100h) is located in the opposite direction of the one end and is the end closest to the free edge of the nail.

[0122] Here, "attaching" means placing the nail sticker on the floor so that the bottom surface of the nail sticker is in contact with the top surface of the flat floor, and more specifically, it can refer to the act of making the adhesive layer of the nail sticker adhere to the top surface of the floor. The floor may be a marble floor, and the floor may be a substrate having a top surface that is wider than the bottom surface of the nail sticker.

[0123] Since the nail sticker includes the soft layer of the above-mentioned embodiment, when pressure is applied to a portion of the top surface of the nail sticker after the nail sticker is attached to the nail, the soft layer under the portion of the top surface to which pressure is applied is pushed out to the adjacent area.

[0124] 7 and 8, when the nail sticker of Fig. 7 is placed on a flat surface and pressure is applied as shown in Fig. 8, the maximum thickness of the area other than the area where pressure is applied increases. Therefore, the thickness of at least a portion of the soft layer located below the other part of the top surface where pressure is not applied increases. This is because the material constituting the soft layer corresponds to a material having the above-mentioned properties. As a result, the maximum thickness of the nail sticker also increases.

[0125] As described above, when pressure is applied to a portion of the upper surface of the nail sticker, the maximum thickness of the soft layer increases, and in the process, the maximum thickness of the nail sticker also increases. After attaching the nail sticker to the nail, a user can apply pressure to a portion of the upper surface of the nail sticker so that a portion of the soft layer moves toward the tip (free edge direction) of the nail.

[0126] As a result, a portion of the soft layer moves toward the tip of the nail sticker, filling the gaps between the nails with the soft layer and effectively maintaining the filled shape, thereby reducing the foreign body sensation felt by the user and increasing the adhesive strength of the nail sticker.

[0127] Furthermore, when a portion of the nail sticker extends beyond the nail area, the soft layer can support the extended and protruding portion of the nail sticker so that it is not deformed.

[0128] In addition, even if the nail surface is uneven, a certain force can be applied to deform the nail so that more of the soft layer is placed on the concave portions of the nail surface, thereby allowing the surface of the applied nail sticker to have a smooth shape even if the nail surface is uneven, thereby improving aesthetics.

[0129] In the nail sticker, the thickness increase rate of the soft layer may be 2% or more according to the following formula 1. Specifically, the thickness increase rate of the soft layer may be 3% or more, more specifically, 3% to 30%, for example, 5% to 20%.

[0130] [Formula 1] Soft layer thickness increase rate = [(A2-A1) / A1] x 100 The A1 is the maximum thickness of the soft layer measured when no pressure is applied to the nail sticker attached to the floor, and the A2 is the maximum thickness of the soft layer measured after applying the pressure for 3 seconds, removing the pressure, and leaving the nail sticker for 30 minutes. The pressure may include applying a force of 38.5 N to an area equivalent to 40% to 80% of the total area of ​​the top surface of the nail sticker in a temperature atmosphere of 36°C.

[0131] The pressure is applied to the upper surface of the nail sticker at a temperature of 36° C. and a force of 38.5 N. The pressure can be applied via a push gage device manufactured by IMADA. The pressure value can also be measured. The lower surface area of ​​the pressure applying member is, for example, 177 mm 2 It may be, but is not limited to this.

[0132] In addition, the pressure is not applied to 1) the fulcrum where the thickness of the soft layer is greatest before the pressure is applied, and 2) the fulcrum where the thickness of the nail sticker is greatest before the pressure is applied. Specifically, the pressure may be applied in a downward direction of 38.5 N to an area corresponding to 40% to 80%, specifically 50% to 70%, for example 60%, of the total area of ​​the upper surface of the nail sticker in a temperature atmosphere of 36°C.

[0133] FIG. 8 is a diagram illustrating the application of pressure, and FIG. 30 is a diagram illustrating the state in which the lower surface of the pressure applying member comes into contact with the upper surface of the nail sticker.

[0134] 8 and 30, the pressure is not directly applied to the fulcrum where the maximum thickness (A1) of the soft layer 110 exists and the fulcrum where the maximum thickness (A2) of the nail sticker 100 exists. In other words, the pressure is applied to a part of the upper surface of the nail sticker, and the part of the upper surface does not include the fulcrum where the maximum thickness of the nail sticker exists and the fulcrum where the maximum thickness of the nail sticker exists.

[0135] More specifically, the nail sticker 100 is placed on a flat floor (F1). The nail sticker 100 may have an asymmetric structure in the longitudinal direction. That is, the thickness of the nail sticker 100 may be asymmetric in the longitudinal direction.

[0136] When pressure is applied, the lower surface (Ps) of the member (P) applying the pressure comes into contact with the area corresponding to 100b in FIG.

[0137] For example, pressure is applied to the pressure applying member (P) from one end of the nail sticker 100 (100g, the end facing the cuticle of the nail when the nail sticker is attached) to a fulcrum that is a distance equivalent to 70% of the length (100L) of the nail sticker 100 from the one end (the area corresponding to 100b in Figure 8).

[0138] Referring to FIG. 30, the area where the lower surface (Ps) of the pressure applying member (P) and the upper surface of the nail sticker 100 intersect can be formed starting from a fulcrum that is a distance equivalent to 70% of the length (100L) of the nail sticker 100 from one end (100g) of the nail sticker, and in a direction toward the one end (100g).

[0139] Here, "attaching" may mean placing the nail sticker on the floor so that the bottom surface of the nail sticker is in contact with the top surface of the flat floor, and more specifically, it may mean making the adhesive layer of the nail sticker adhere to the top surface of the floor. The floor may be a marble floor, and a substrate having a top surface wider than the bottom surface of the nail sticker may be considered as the floor.

[0140] Here, the nail sticker may be the same as the nail sticker described above. The soft layer, coating layer, base layer, etc. of the nail sticker described above may also be included in the nail sticker of this embodiment.

[0141] Meeting the range of the thickness increase rate of the soft layer means that when pressure is applied to the upper surface of the nail sticker, the soft layer is moved from the inside of the nail sticker, the maximum thickness of the soft layer can be increased, and the deformed soft layer can effectively maintain its shape even when the pressure is removed.

[0142] Referring to Figures 7 and 8, when the nail sticker of Figure 7 is placed on a flat floor and then pressure is applied as shown in Figure 8, the maximum thickness of the areas other than the area where pressure is applied increases.

[0143] Furthermore, when the nail sticker of the present invention is viewed in the longitudinal direction of the nail sticker (cross section taken along AA' in Figure 4), the fulcrum at which the maximum thickness of the soft layer is indicated before pressure is applied is biased toward one end of the nail sticker, and the thickness of the nail sticker can be asymmetric in the longitudinal direction of the nail sticker.

[0144] In this case, when pressure is applied to the center of the top surface of the nail sticker, most of the soft layer within the nail sticker is moved in one direction, and the maximum thickness is observed in the area adjacent to one end of the nail sticker, and it can be seen that this value is larger than the maximum thickness before pressure is applied.

[0145] Furthermore, as shown in Figure 9, even after the pressure is removed and the nail sticker is left for a certain period of time, the deformed nail sticker does not easily return to its original shape.

[0146] The effects of the physical properties of the nail sticker are as follows.

[0147] When pressure is applied to a portion of the upper surface of the nail sticker as described above, the maximum thickness of the soft layer increases, so that after the user attaches the nail sticker to the nail, the user can apply pressure to a portion of the upper surface of the nail sticker so that a portion of the soft layer moves toward the tip (free edge direction) of the nail.

[0148] Here, the increase in maximum thickness does not mean an increase in the thickness of the area where pressure is applied, but rather an increase in the maximum thickness of the soft layer among the thicknesses of areas other than the area where pressure is applied. In addition, the fulcrum indicating the maximum thickness before and after pressure application may be different.

[0149] As a result, a portion of the soft layer moves toward the tip of the nail sticker, filling the floating space between the nail and the nail sticker with the soft layer and effectively maintaining the filled shape, thereby reducing the foreign body sensation felt by the user and increasing the adhesive strength of the nail sticker.

[0150] Furthermore, when a portion of the nail sticker extends beyond the nail area, the soft layer can support the extended and protruding portion of the nail sticker so that it is not deformed.

[0151] In addition, even if the nail surface is uneven, a certain force can be applied to deform the nail so that more of the soft layer is placed on the concave portions of the nail surface, thereby allowing the surface of the applied nail sticker to have a smooth shape even if the nail surface is uneven, thereby improving aesthetics.

[0152] In addition, satisfying the range of the thickness increase rate of the soft layer means that the above-mentioned effects can be maintained continuously and well while the user is using the nail.

[0153] A nail sticker according to another embodiment of the present invention is a hardenable nail sticker, and the nail sticker includes a soft layer. When the nail sticker is attached to a flat surface and pressure is applied to a portion of the upper surface of the nail sticker, the maximum thickness of the nail sticker can be increased. Here, the nail sticker may be the same as the nail sticker described above. The soft layer, coating layer, substrate layer, etc. of the nail sticker described above may also be included in the nail sticker of this embodiment.

[0154] The conditions for applying the pressure are the same as those described in relation to Equation 1 in the nail sticker according to the above embodiment, and therefore, the description thereof will be omitted.

[0155] Since the nail sticker includes the soft layer of the above-mentioned embodiment, after the nail sticker is attached to the nail, when pressure is applied to a part of the top surface of the nail sticker, the soft layer under the part of the top surface where pressure is applied is pushed out to the adjacent area.

[0156] Referring to Figures 7 and 8, when the nail sticker of Figure 7 is placed on a flat floor and then pressure is applied as in Figure 8, the maximum thickness of the areas other than the area where pressure is applied increases.

[0157] Therefore, the thickness of at least a portion of the soft layer located below the other portion of the upper surface where pressure is not applied increases because the material constituting the soft layer corresponds to a material having the above-mentioned properties, and thus the maximum thickness of the nail sticker also increases.

[0158] As described above, when pressure is applied to a portion of the upper surface of the nail sticker, the maximum thickness of the soft layer increases, and in the process, the maximum thickness of the nail sticker also increases. After attaching the nail sticker to the nail, a user can apply pressure to a portion of the upper surface of the nail sticker so that a portion of the soft layer moves toward the tip (free edge) of the nail.

[0159] As a result, a portion of the soft layer moves toward the tip of the nail sticker, filling the floating space between the nail and the nail sticker with the soft layer and effectively maintaining the filled shape, thereby reducing the foreign body sensation felt by the user and increasing the adhesive strength of the nail sticker.

[0160] Furthermore, when a portion of the nail sticker extends beyond the nail area, the soft layer can support the extended and protruding portion of the nail sticker so that it is not deformed.

[0161] In addition, even if the nail surface is uneven, a certain force can be applied to deform the nail so that more of the soft layer is placed on the concave portions of the nail surface, thereby allowing the surface of the applied nail sticker to have a smooth shape even if the nail surface is uneven, thereby improving aesthetics.

[0162] In the nail sticker, the thickness increase rate of the nail sticker may be 2% or more according to the following formula 2. Specifically, the thickness increase rate of the nail sticker may be 3% or more, more specifically, 3% to 30%, for example, 5% to 20%.

[0163] [Formula 2] Nail sticker thickness increase rate = [(B2-B1) / B1] x 100 B1 is the maximum thickness of the nail sticker measured when no pressure is applied to the nail sticker attached to the floor, and B2 is the maximum thickness of the nail sticker measured after applying the pressure for 3 seconds and leaving the nail sticker for 30 minutes after removing the pressure, and the pressure may include applying a force of 38.5 N to an area equivalent to 40% to 80% of the total area of ​​the top surface of the nail sticker in a temperature atmosphere of 36°C.

[0164] Here, the nail sticker may be the same as the nail sticker described above. The soft layer, coating layer, substrate layer, etc. of the nail sticker described above may also be included in the nail sticker of this embodiment. The conditions for applying the pressure are the same as those described in relation to Equation 1 for the nail sticker according to the embodiment described above, so further description will be omitted.

[0165] Meeting the range of the thickness increase rate of the nail sticker means that when pressure is applied to the upper surface of the nail sticker, the soft layer is moved from the inside of the nail sticker, the maximum thickness of the soft layer can increase, and the deformed soft layer can effectively maintain its shape even when the pressure is removed.

[0166] 7 and 8, when the nail sticker of Fig. 7 is placed on a flat floor and pressure is applied as in Fig. 8, the maximum thickness of the area other than the area where pressure is applied increases. Furthermore, when the nail sticker of the present invention is viewed in the longitudinal direction of the nail sticker (cross section confirmed along AA' in Fig. 4), the fulcrum where the maximum thickness of the soft layer is shown before pressure is applied is biased to one end side of the nail sticker, so the thickness of the nail sticker can be asymmetric in the longitudinal direction of the nail sticker.

[0167] In this case, when pressure is applied to the center of the top surface of the nail sticker, most of the soft layer within the nail sticker is moved in one direction, and the maximum thickness is observed in the area adjacent to one end of the nail sticker, which is a larger value than the maximum thickness before pressure was applied.

[0168] Also, as shown in Figure 9, even if the pressure is removed and the nail sticker is left for a certain period of time, the deformed nail sticker does not easily return to its original shape.

[0169] The effects of the physical properties of the nail sticker are as follows.

[0170] When pressure is applied to a portion of the upper surface of the nail sticker as described above, the maximum thickness of the soft layer increases, so after the user attaches the nail sticker to the nail, they can apply pressure to a portion of the upper surface of the nail sticker so that a portion of the soft layer moves toward the tip (free edge direction) of the nail.

[0171] Here, the increase in maximum thickness does not mean an increase in the thickness of the area where pressure is applied, but rather an increase in the maximum thickness of the soft layer among the thicknesses of areas other than the area where pressure is applied. In addition, the fulcrum indicating the maximum thickness before and after pressure application may be different.

[0172] As a result, a portion of the soft layer moves toward the tip of the nail sticker, filling the floating space between the nail and the nail sticker with the soft layer and effectively maintaining the filled shape, thereby reducing the foreign body sensation felt by the user and increasing the adhesive strength of the nail sticker.

[0173] 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. Also, even if the nail surface is uneven, a predetermined force can be applied to deform the nail so that more of the soft layer is disposed on the concave portion of the nail surface.

[0174] Therefore, even if the nail surface is uneven, the surface of the applied nail sticker can have a smooth shape, thereby improving aesthetics. In addition, satisfying the range of the thickness increase rate of the soft layer means that the above-mentioned effects can be continuously and well maintained while the user is using the nail.

[0175] According to another embodiment of the present invention, a nail sticker is curable, the nail sticker includes a soft layer, and a rectangular parallelepiped substrate having a thickness of 0.7 mm is prepared and placed on a flat floor. The nail sticker is attached to the upper surface of the substrate so that an area having a length equivalent to 70% of the total length of the nail sticker is in contact with the flat upper surface of the substrate. In an atmosphere having a temperature of 36°C, a force of 38.5 N is applied in the direction of the floor to at least a part of the upper surface of the part of the nail sticker that overlaps the substrate in the vertical direction. After the force is removed and the mixture is left at 36°C for 30 minutes, the shortest distance between the area of ​​the part of the nail sticker that does not overlap the substrate in the vertical direction and protrudes from the substrate and contacts the floor and the substrate is 1.5 mm or less, and the force can be applied to an area equivalent to 40% to 80% of the total area of ​​the upper surface of the nail sticker.

[0176] Specifically, the shortest distance (D) can be 0 mm to 1.3 mm, more specifically 0 mm to 1.0 mm.

[0177] Here, the soft layer may be the same as the soft layer described in the nail sticker of the above-mentioned embodiment, and the nail sticker may also be the same as the nail sticker of the above-mentioned embodiment. Therefore, all of the components described in the nail sticker of the above-mentioned embodiment, such as the base layer, soft layer, and coating layer, may be the same as the components of the nail sticker of this embodiment.

[0178] The above content will be explained below with reference to FIG. 12. A substrate (S) is placed on a flat floor (F). The substrate (S) may be a rectangular parallelepiped and have a predetermined thickness (T), which may be 0.7 mm. A portion of the nail sticker 100 is attached to the substrate (S) so that a portion of the nail sticker 100 overlaps the substrate (S) in the vertical direction (H).

[0179] In this case, the length of the portion of the nail sticker 100 may be 70% of the entire length of the nail sticker 100. Here, the entire length refers to the longest side of the nail sticker in the AA' direction when referring to Fig. 2, and the length of the portion of the nail sticker 100 refers to a portion of the entire length of the nail sticker in the AA' direction. When a portion of the nail sticker 100 is attached to the substrate (S) in this manner, a protruding portion (100p) of the nail sticker 100 is not overlapped with the substrate (S) in the vertical direction (H) and is separated from the substrate (S), and the length of the protruding portion (100p) may be 30% of the entire length of the nail sticker.

[0180] At this time, the protruding portion (100p) bends toward the floor (F) and has an area that contacts the floor (F). After removing the pressure and leaving it at 36°C for 30 minutes, the shortest distance (D) between the area and the substrate (S) can be measured.

[0181] Meanwhile, the fulcrum where the thickness of the nail sticker 100 is maximum before pressure is applied may belong to the protruding portion (100p). The force may be applied to an area corresponding to 40% to 80%, specifically 50% to 70%, for example 60%, of the total area of ​​the upper surface of the nail sticker.

[0182] The force is applied to a part of the upper surface of the nail sticker at a temperature of 36°C. The pressure can be applied using a push gage device manufactured by IMADA, and the pressure value can be measured. The lower surface area of ​​the pressure applying member is, for example, 177 mm 2 It may be, but is not limited to this.

[0183] The feature that the shortest distance (D) is 1.5 mm or less can be achieved because the nail sticker includes a soft layer. When pressure is applied to the top surface of the nail sticker, the soft layer inside the nail sticker is deformed and moves partially toward the floor. This allows the protruding portion 100a to contact the floor (F) without a large shortest distance (D).

[0184] This feature is very effective when the nail sticker is attached to the user's nail. That is, when the user applies a certain amount of force when attaching the nail sticker 100 to the nail, the soft layer can effectively fill the floating space between the nail and the nail sticker.

[0185] This reduces contamination of the nail sticker by foreign matter, reduces the foreign body sensation felt by the user, and further improves the adhesive strength of the nail sticker.

[0186] 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. Also, even if the nail surface is uneven, the surface of the applied nail sticker can have a smooth shape, thereby improving aesthetics.

[0187] Conversely, if the shortest distance (D) is too large, exceeding 1.5 mm, it means that deformation of the soft layer is unlikely to occur, and therefore, even if the user applies a certain amount of force in the process of attaching the nail sticker 100 to the nail, it is difficult for the soft layer to fill the floating space between the nail and the nail sticker.

[0188] In addition, since the soft layer is difficult to move, the uneven shape of the nail surface is directly reflected on the surface of the nail sticker, and the surface of the nail sticker also has an uneven shape.Furthermore, there is a problem that the shape of the nail sticker is easily deformed.

[0189] In the following, preferred embodiments are presented to aid in understanding the present invention. However, the above embodiments 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 and technical spirit of the present description. It is to be understood that such changes and modifications fall within the scope of the appended claims.

[0190] <Examples and Comparative Examples> Example 1 A nail sticker was prepared, including a base layer (thickness: 150 μm), a soft layer (maximum thickness: 1380.3 μm) disposed on the base layer, and a coating layer (maximum thickness: 65 μm) disposed on the soft layer. The base layer included an adhesive layer (maximum thickness: 50 μm) and a printing layer (maximum thickness: 100 μm) disposed on the adhesive layer. The adhesive layer constituted the underside of the nail sticker.

[0191] 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.

[0192] 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.

[0193] Comparative Example 1 A nail sticker was prepared, including a base layer (thickness: 150 μm), a first coating layer (maximum thickness: 1182.6 μm) disposed on the base layer, and a second coating layer (maximum thickness: 65 μm) disposed on the first coating layer. The base layer included an adhesive layer (maximum thickness: 50 μm) and a printing layer (maximum thickness: 100 μm) disposed on the adhesive layer. The adhesive layer constituted the underside of the nail sticker.

[0194] 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.

[0195] 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.

[0196] Experimental Example 1 The physical properties of the nail stickers of Example 1 and Comparative Example 1 were confirmed as follows.

[0197] A rectangular parallelepiped substrate with a thickness of 0.7 mm was prepared and placed on a flat floor. A portion of the nail sticker was attached to the top surface of the substrate so that an area having a length equivalent to 70% of the total length of the nail sticker was in contact with the flat top surface of the substrate. A force of 38.5 N was applied in an atmosphere at a temperature of 36°C for 3 seconds to the area where the nail sticker and the substrate overlapped each other in the vertical direction (an area equivalent to 60% of the total area of ​​the top surface of the nail sticker). The pressure was then removed and the nail sticker was left at 36°C for 30 minutes.

[0198] Thereafter, the shortest distance between the area where the portion of the nail sticker that was not vertically overlapped with the substrate and that was led out from the substrate and contacted the floor and the substrate was measured.

[0199] FIG. 28 shows photographs of the experimental results of Example 1, and FIG. 29 shows photographs of the experimental results of Comparative Example 1.

[0200] [Table 1]

[0201] Experimental Example 2 The nail stickers of Example 1 and Comparative Example 1 were subjected to the following experiments.

[0202] Figure 13 is a cross-sectional photograph of the nail sticker of Example 1, with the adhesive layer attached to the top surface of a flat floor so that the bottom surface of the nail sticker faces the top surface of the flat floor, before pressure is applied.

[0203] FIG. 14 shows the results of the measurement of the nail sticker of Example 1 stuck on the floor as shown in FIG. 13 in a 36° C. atmosphere. 2This is a cross-sectional photograph taken after applying a force of 38.5 N to a portion of the upper surface of the nail sticker (an area equivalent to 60% of the total area of ​​the upper surface, but not including the fulcrum where the nail sticker and soft layer are at their maximum thickness) for 3 seconds using a pressure member with a bottom surface (circular) of an area of ​​100 mm, and then removing the force and leaving the nail sticker in an atmosphere at a temperature of 36°C for 30 minutes.

[0204] The cross sections of Figures 13 and 14 correspond to cross sections of the nail sticker cut along AA' in Figure 4. The maximum thickness and thickness increase rate measured through Figures 13 and 14 are shown in Table 2.

[0205] The same method was used to measure Comparative Example 1, and the results are shown in Table 2. Figure 15 is a cross-sectional photograph of Comparative Example 1, taken after the adhesive layer of the nail sticker was attached to the upper surface of a flat floor with the bottom surface of the nail sticker facing the upper surface of the flat floor, and before pressure was applied. Figure 16 is a cross-sectional photograph taken after pressure was applied under the same conditions as described above, the pressure was removed, and the sticker was left as it was.

[0206] [Table 2]

[0207] The thickness increase rate of the soft layer was calculated as follows.

[0208] [Formula 1] Soft layer thickness increase rate (%) = [(A2-A1) / A1] x 100 A1 is the maximum thickness of the soft layer measured when no pressure is applied to the nail sticker attached to the floor, and A2 is the maximum thickness of the soft layer measured after applying the pressure for 3 seconds, removing the pressure, and leaving the nail sticker for 30 minutes, where the pressure was applied by applying a force of 38.5 N to an area equivalent to 60% of the total area of ​​the top surface of the nail sticker in a temperature atmosphere of 36° C. Meanwhile, when applying Equation 1 to Comparative Example 1, the first coating layer of Comparative Example 1 was made to correspond to the soft layer of Example 1.

[0209] The thickness increase rate of the nail sticker was calculated as follows:

[0210] [Formula 2] Nail sticker thickness increase rate = [(B2-B1) / B1] x 100 B1 is the maximum thickness of the nail sticker measured when no pressure is applied to the nail sticker attached to the floor, and is the maximum thickness of the nail sticker measured after applying the pressure for 3 seconds, removing the pressure, and leaving the nail sticker for 30 minutes, and the pressure was applied by applying a force of 38.5 N to an area equivalent to 60% of the total area of ​​the top surface of the nail sticker in a temperature atmosphere of 36°C.

[0211] Experimental Example 3 The nail stickers of Example 1 and Comparative Example 1 were subjected to the following experiments.

[0212] The nail sticker was placed on the curved nail surface so that the bottom surface of the nail sticker (the surface with the exposed adhesive layer) was in contact with the curved nail surface, and then the nail sticker was attached to the nail by applying a predetermined force with a finger. 2 Under the above conditions of light intensity, 6W output, and rated voltage of 5V / 1.2A, the nail sticker was cured by irradiating it with ultraviolet light having a wavelength of 395nm twice for 45 seconds.

[0213] This is shown in FIG. 17 (nail sticker of Example 1) and FIG. 18 (nail sticker of Comparative Example 1).

[0214] 17, it can be seen that the surface of the nail sticker is smooth and without any depressions. On the other hand, 18 shows that the surface of the nail sticker is partially depressed in the area located near the tip of the nail. That is, in the case of Example 1, part of the soft layer moves toward the tip of the nail during the process of attaching the nail sticker to the nail, making the soft layer thicker near the tip of the nail, and this thickened soft layer prevents a gap from forming between the nail and the nail sticker.

[0215] This can be seen more clearly in Figure 19 (cross section of the nail sticker of Example 1) and Figure 20 (cross section of the nail sticker of Comparative Example 1). Looking at Figure 19, it can be seen that the nail sticker of Example 1 is attached as closely as possible to the nail in the area where it overlaps the nail in the vertical direction.

[0216] In particular, the thickness increases toward the tip of the nail while maintaining contact with the nail, because the soft layer inside the nail sticker moves toward the tip of the nail, maintaining a state in which the nail sticker and the nail can be in continuous contact. On the other hand, as can be seen from Figure 20, the nail sticker of Comparative Example 1 does not adhere to the nail near the tip of the nail.

[0217] Experimental Example 4 On the other hand, for Example 1 and Comparative Example 1, the nail stickers were attached and cured under the same conditions as in Experimental Example 1, and then the nail stickers were peeled off and the undersides of the nail stickers were observed. Figure 21 shows the underside of the nail sticker for Example 1, and Figure 22 shows the underside of the nail sticker for Comparative Example 1.

[0218] 21, in the case of Example 1, the soft layer moves toward the tip of the nail, and a portion of the nail sticker in the middle that is thicker than the periphery forms a nail line. In other words, this portion effectively connects the nail and the nail sticker, maintaining the shape of the nail sticker. On the other hand, in the case of the nail sticker of Comparative Example 1, no thick portion due to layer movement was observed on the underside.

[0219] Experimental Example 5 Figure 23 is a photograph of a nail with a severely curved surface. Specifically, the nail in Figure 23 includes a convex protruding portion on the top surface of the nail.

[0220] The nail stickers of Example 1 and Comparative Example 1 were attached to the nail of FIG. 23 under the same conditions as in Experimental Example 1 and cured.

[0221] 24, even if the nail surface is severely curved, no unevenness is observed on the top surface of the nail sticker of Example 1. This is because the soft layer in the nail sticker of Example 1 can move effectively (see the cross-sectional view of FIG. 11), and the shape of the soft layer can be changed so that the surface of the nail sticker has a smooth shape.

[0222] On the other hand, referring to Fig. 25, it can be seen that the nail sticker of Comparative Example 1, which does not include a soft layer, has a problem in that the curvature of the nail surface is reflected on the top surface of the nail sticker. Specifically, the top surface of the nail sticker in Fig. 25 includes a convex area corresponding to the convex part of the top surface of the nail.

[0223] Experimental Example 6 Figure 23 is a photograph of a nail with a severely curved surface.

[0224] In each of Example 1 and Comparative Example 1, a nail sticker was attached to the nail shown in Fig. 23 and cured under the same conditions as in Experimental Example 1. After that, the nail sticker was peeled off and the underside was observed.

[0225] Referring to Figure 27, in the case of the nail sticker of Comparative Example 1, since the underside of the nail sticker does not easily come into contact with the concave area of ​​the nail, some areas of the underside of the nail sticker that are separated from the nail surface remain as smooth areas of the adhesive layer (the non-smooth areas mean that the adhesive components of the adhesive layer have aggregated together to form a mesh-like structure while the nail and adhesive layer are in contact).

[0226] On the other hand, referring to Figure 26, in the case of the nail sticker of Example 1, the movement of the soft layer allows the underside of the nail sticker to effectively fill in the concave areas of the nail, so there are no smooth areas on the underside of the nail sticker. [Explanation of symbols]

[0227] 1: Conventional nail stickers 2: Nails 3: Finger 100: Nail stickers 110: Soft layer 120: Base material layer 130: Coating layer S: Substrate F1, F2: Floor

Claims

1. A curable nail sticker, 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 ultraviolet-curable raw material for the soft layer includes at least one of a urethane acrylate oligomer, a polyester acrylate oligomer, and an epoxy acrylate oligomer; 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, A nail sticker in which the maximum thickness of the soft layer increases when the nail sticker is attached to a flat floor and pressure is applied to a part of the upper surface of the nail sticker.

2. The coating layer includes an ultraviolet-curable raw material for the coating layer and a resin for the coating layer. The nail sticker according to claim 1 .

3. The thickness increase rate of the soft layer according to the following formula 1 is 2% or more, The nail sticker according to claim 2. [Formula 1] Soft layer thickness increase rate = [(A ２ -A １ ) / A １ ] x 100 The above A １ is the maximum thickness of the soft layer measured when no pressure is applied to the nail sticker attached to the floor, The above A ２ is the maximum thickness of the soft layer measured after applying the pressure for 3 seconds, removing the pressure, and then leaving the nail sticker in an atmosphere at a temperature of 36°C for 30 minutes; The pressure includes applying a force of 38.5 N to an area corresponding to 40% to 80% of the total area of ​​the upper surface of the nail sticker in a temperature atmosphere of 36°C.

4. The thickness increase rate of the nail sticker according to the following formula 2 is 2% or more: The nail sticker according to claim 3. [Formula 2] Nail sticker thickness increase rate = [(B ２ -B １ ) / B １ ] x 100 B １ is the maximum thickness of the nail sticker measured when no pressure is applied to the nail sticker attached to the floor, B ２ is the maximum thickness of the soft layer measured after applying the pressure for 3 seconds, removing the pressure, and then leaving the nail sticker in an atmosphere at a temperature of 36°C for 30 minutes; The pressure includes applying a force of 38.5 N to an area corresponding to 40% to 80% of the total area of ​​the upper surface of the nail sticker in a temperature atmosphere of 36°C.

5. A method for manufacturing the nail sticker according to claim 1, The nail sticker includes a soft layer, A rectangular parallelepiped substrate having a thickness of 0.7 mm is prepared and placed on a flat floor, and the nail sticker is attached to the upper surface of the substrate so that an area having a length corresponding to 70% of the total length of the nail sticker is in contact with the flat upper surface of the substrate. In an atmosphere having a temperature of 36°C, a force of 38.5 N is applied in the direction of the floor to at least a part of the upper surface of the part of the nail sticker that overlaps the substrate in the vertical direction, and then the force is removed and the nail sticker is left at 36°C for 30 minutes, and then measurement is performed. The shortest distance between the area of ​​the part of the nail sticker that does not overlap the substrate in the vertical direction and protrudes from the substrate and contacts the floor and the substrate is 1.5 mm or less. The method wherein the force is applied to an area corresponding to 40% to 80% of the total area of ​​the top surface of the nail sticker.

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