Skin adhesive sheet

Abstract

The present invention provides a skin-adhesive sheet with improved adhesion of the display layer to a substrate containing polyurethane resin. [Solution] The skin-adhesive sheet 10 comprises a base material 12 containing a polyurethane resin and an adhesive layer 13 that is attached to the skin. The first surface 12A of the base material 12, opposite to the surface facing the adhesive layer 13, is the target for forming a display layer containing a coloring agent that is configured to display predetermined information. The wetting tension of the first surface 12A, calculated in accordance with JIS K 6768:1999, is 50 mN / m or more, and the arithmetic mean roughness Sa of the first surface 12A, calculated in accordance with ISO 25178-2:2012, is 0.2 μm or more.

Description

Technical Field

[0001] The present disclosure relates to a skin patch sheet.

Background Art

[0002] In order to protect the skin from friction and irritation, sheets that are directly attached to the skin are widely used. An example of a skin patch sheet is a laminate including a carrier sheet, a base material, an adhesive layer, and a release layer. When using a skin patch sheet, first, the release layer is peeled off from the adhesive layer. Then, after attaching the skin patch sheet to the skin, the carrier sheet is peeled off from the base material (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, information such as the date and time when the skin patch sheet is attached to the skin is described on the surface of the base material in the skin patch sheet. At this time, if bleeding or repelling of the ink used for the description of the information occurs on the surface, the description of the information itself may not be possible, or the intended information may not be described. Further, if the ink once fixed on the surface easily detaches from the surface due to friction against the surface or wetting of the surface, it becomes difficult to confirm the information after a certain period has elapsed since the description of the information.

Means for Solving the Problems

[0005] A skin-adhesive sheet for solving the above problems comprises a base material containing a polyurethane resin and an adhesive layer that is attached to the skin, wherein the surface of the base material opposite to the surface facing the adhesive layer is the object on which a display layer containing a coloring agent configured to display predetermined information is formed, the wetting tension of the surface calculated in accordance with JIS K 6768:1999 is 50 mN / m or more, and the arithmetic mean roughness Sa of the surface calculated in accordance with ISO 25178-2:2012 is 0.2 μm or more.

[0006] According to the above configuration, bleeding and repulsion of the display layer onto the substrate containing polyurethane resin are suppressed, and the display layer is fixed. Furthermore, even if friction occurs against the display layer or the surface of the adhesive layer becomes wet, the display layer will not easily detach.

[0007] In the above-described skin-adhesive sheet, the polyurethane resin may be an aqueous polyurethane containing an ether polyol. With this configuration, the display layer can be fixed to the substrate containing the aqueous polyurethane containing an ether polyol.

[0008] The above-described skin-adhesive sheet comprises a sheet body including the base material and the adhesive layer, and the 100% modulus of the sheet body may be 2.0 MPa or less. This configuration improves the skin-adhesive sheet's conformability to the skin.

[0009] In the above-described skin-adhesive sheet, the display layer may be further provided, and the coloring agent may be a heat-sensitive material. With this configuration, the display layer that responds to temperature changes can be fixed in place. The above-described skin-adhesive sheet comprises a carrier sheet having a matte surface and a tensile break elongation lower than that of the base material, wherein the matte surface is in contact with the surface of the base material facing the adhesive layer, and the thickness of the base material may be 5 μm or more and 30 μm or less.

[0010] In the above-described skin-adhesive sheet, the surface of the substrate is a peel surface that has been peeled from the mat surface of a carrier sheet having a lower tensile break elongation than the substrate, and the thickness of the substrate may be 5 μm or more and 30 μm or less.

[0011] According to the above configurations, since the carrier sheet has a lower tensile elongation than the substrate, the aforementioned roughness is easily formed on the surface of the substrate due to the irregularities of the mat surface. As a result, the variation in the irregularities on the surface of the substrate, and consequently the variation in the arithmetic mean roughness Sa, is suppressed by the amount that the carrier sheet has a lower tensile elongation than the substrate.

[0012] In the above-described skin-adhesive sheet, the 100% modulus of the sheet body may be 2.0 MPa or less, and the arithmetic mean roughness Sa on the surface may be 0.6 μm or more. With this configuration, no bleeding or repulsion of the display layer is observed on the substrate containing polyurethane resin, and the display layer is fixed. Furthermore, even if friction occurs against the display layer or the surface of the display layer becomes wet, the display layer does not easily detach. In addition, it conforms well to the skin, and the sheet does not easily peel off even if friction or wetness occurs.

[0013] The above-described skin-adhesive sheet may further include the display layer, wherein the polyurethane resin is an aqueous polyurethane containing an ether-based polyol, the adhesive layer contains a urethane-based adhesive, and the display layer contains an aqueous ink. This configuration enhances the effectiveness of achieving the above-described effects.

[0014] A skin-adhesive sheet for solving the above problems comprises a carrier sheet, a release layer, and a sheet body located between the carrier sheet and the release layer, wherein the sheet body comprises a base material containing the polyurethane resin and having a higher tensile break elongation than the carrier sheet and the release layer, and an adhesive layer in contact with the release layer and attached to the skin, wherein the area of ​​the carrier sheet is larger than the area of ​​the sheet body, the carrier sheet includes a first region which does not overlap with the sheet body and a second region which overlaps with the sheet body, and the carrier sheet has a cut that, when viewed from a viewpoint opposite to the plane on which the carrier sheet extends, extends from the portion of the outer edge of the carrier sheet included in the first region toward the sheet body, beyond the boundary between the first region and the second region, wherein the depth of the cut in the second region is shallower than the depth in the first region, and the depth D1 of the cut may satisfy the following formula using the thickness T of the carrier sheet.

[0015] 1 / 4T ≤ D1 ≤ T According to the above configuration, the portion of the cut located on the sheet body does not penetrate the carrier sheet. Therefore, during the manufacturing of the skin-adhesive sheet, the cutting of the base material together with the carrier sheet is suppressed, and before the skin-adhesive sheet is used, foreign matter is prevented from reaching the base material through the cut. Furthermore, bleeding and repulsion of the display layer onto the base material containing polyurethane resin are suppressed, and the display layer is fixed. In addition, even if friction occurs against the display layer or the surface of the adhesive layer becomes wet, the display layer will not easily detach. [Effects of the Invention]

[0016] According to the skin-adhesive sheet of this disclosure, bleeding and repelling are suppressed in the display layer that displays information such as the date and time the skin-adhesive sheet was applied to the skin and the planned date and time for removal. In addition, it is possible to suppress the easy detachment of the display layer from the surface once it has been fixed to the surface due to friction with the surface of the substrate or surface wetting. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a cross-sectional view showing the structure of the skin patch sheet. [Figure 2] Figure 2 is a cross-sectional view showing a part of the structure of the skin patch sheet. [Figure 3] Figure 3 is a cross-sectional view showing a part of the structure of the skin patch sheet. [Figure 4] Figure 4 is a cross-sectional view showing the structure of the sheet body. [Figure 5] Figure 5 is a cross-sectional view showing the structure of the sheet body. <000008�>Figure 6 is a table showing the evaluation results of the skin patch sheets of the examples and comparative examples. [Figure 7] Figure 7 is a cross-sectional view showing the structure of the first modified example of the skin patch sheet. [Figure 8] Figure 8 is a plan view showing the structure of the first modified example of the skin patch sheet shown in Figure 7. [Figure 9] Figure 9 is a cross-sectional view showing a part of the carrier sheet and a part of the base material in the first modified example of the skin patch sheet shown in Figure 7.

Mode for Carrying Out the Invention

[0018] Referring to FIGS. 1 to 9, embodiments of the skin patch sheet will be described. [[ID=�6]] [Skin Patch Sheet 10] First, referring to FIGS. 1 to 6, the configuration of the skin patch sheet 10 will be described.

[0019] As shown in Figure 1, the skin-adhesive sheet 10 is a laminate comprising a display layer 11, a base material 12, an adhesive layer 13, and a release layer 14. The base material 12 has a first surface 12A and a second surface 12B. At least one of the first surface 12A and the second surface 12B is the surface on which the display layer 11 is formed. The adhesive layer 13 is located on one of the two surfaces of the base material 12. The display layer 11 is located on the surface of the base material 12 opposite to the surface facing the adhesive layer 13. The release layer 14 is in contact with the adhesive layer 13. The adhesive layer 13 is attached to the skin after the release layer 14 is peeled off from the adhesive layer 13.

[0020] The wetting tension of the surface of the substrate 12 in contact with the display layer 11, calculated in accordance with JIS K 6768:1999, is 50 mN / m or more. The wetting tension is a value measured by a method in accordance with JIS K 6768:1999 "Plastics - Films and sheets - Wetting tension test method".

[0021] The arithmetic mean roughness Sa of the surface of the substrate 12 in contact with the display layer 11, calculated in accordance with ISO 25178-2:2012, is 0.2 μm or greater. The arithmetic mean roughness Sa is a value measured by a method in accordance with ISO 25178-2:2012 "Surface properties parameters".

[0022] The skin-adhesive sheet 10 may have a rectangular shape. Alternatively, the skin-adhesive sheet 10 may have a geometric shape such as a triangle, square, polygon with pentagons or more, circle, or ellipse, or it may have an irregular shape other than a geometric shape.

[0023] [Structure of each layer] The following describes the structure of each layer of the skin-adhesive sheet 10. Figure 2 shows the cross-sectional structure of the laminate of the carrier sheet 15 and the base material 12. The laminate of the carrier sheet 15 and the base material 12 may be used as an intermediate in the manufacturing process of the skin-adhesive sheet 10. Figure 3 shows the cross-sectional structure of the laminate of the adhesive layer 13 and the release layer 14. The laminate of the adhesive layer 13 and the release layer 14 may be used as an intermediate in the manufacturing process of the skin-adhesive sheet 10. Figure 4 shows the cross-sectional structure of the sheet body 10A equipped with a display layer 11. The display layer 11 may be formed as part of the sheet body 10A during the manufacturing process of the skin-adhesive sheet 10, or it may be formed separately on the sheet body 10A as a separate component when using the skin-adhesive sheet 10.

[0024] [Base material 12] As shown in Figure 2, the base material 12 may be formed on a carrier sheet 15. In this case, the carrier sheet 15 is in contact with the first surface 12A of the base material 12. The base material 12 formed on the carrier sheet 15 is bonded to the adhesive layer 13. After that, the carrier sheet 15 may be peeled off from the base material 12.

[0025] The constituent materials of the base material 12 include a polyurethane resin. The polyurethane resin enhances adhesion suitability, such as deformation to conform to the shape of the human skin surface and adhesion suitable for the properties of the human skin surface. The polyurethane resin is a polyurethane obtained by the reaction of a compound having two or more hydroxyl groups with a diisocyanate compound. The polyurethane resin may also be obtained by the reaction of a glycol having active hydrogen at its terminus with a diisocyanate. The glycol having active hydrogen at its terminus may be a polyether polyol, a polyester polyol, or a polycarbonate polyol. The polyurethane resin may also be an aqueous polyurethane resin containing an ether polyol. The aqueous polyurethane resin may contain multiple types of ether polyols.

[0026] The thickness of the substrate 12 may be 5 μm or more and 30 μm or 10 μm or more and 20 μm or less. A thin substrate 12 made of polyurethane resin and with a thickness of 30 μm or less stretches well even with a small external force applied to the substrate 12 to stretch it.

[0027] The material of the carrier sheet 15 has a lower tensile elongation at break than the base material 12. The material of the carrier sheet 15 may be a polyolefin resin such as polypropylene (PP) resin or polyethylene (PE) resin, or a polyester resin such as polyethylene terephthalate (PET) resin or polyethylene naphthalate (PEN) resin. The carrier sheet 15 may be a uniaxially oriented sheet, a biaxially oriented sheet, or an unoriented sheet.

[0028] The thickness of the carrier sheet 15 may be 10 μm or more and 400 μm or less, 30 μm or more and 300 μm or less, or 40 μm or more and 100 μm or less. The carrier sheet 15 may be a single-layer sheet or a multi-layer sheet. If the carrier sheet 15 is a multi-layer sheet, the constituent materials of each layer laminated via the adhesive layer may be different materials or the same material. The contact surface of the carrier sheet 15 with a thickness of 10 μm or more easily obtains the irregularities necessary to obtain the arithmetic mean roughness Sa described above.

[0029] The carrier sheet 15 may have a pair of opposing surfaces in the thickness direction, one of which may be a matte surface and the other a glossy surface. Both surfaces of the carrier sheet 15 may be either matte or glossy. When the contact surface of the carrier sheet 15 that contacts the substrate 12 is a matte surface, the irregularities of the matte surface of the carrier sheet 15 are reflected on the surface of the substrate 12. The matte surface has a greater arithmetic mean roughness Sa than the glossy surface.

[0030] The carrier sheet 15 may have a surface treated to facilitate the removal of the base material 12 from the contact surface with the base material 12. The treatment of the contact surface of the carrier sheet 15 may be embossing or a surface treatment by chemical modification.

[0031] [Adhesive layer 13] As shown in Figure 3, the adhesive layer 13 may be formed on the release layer 14. The adhesive layer 13 formed on the release layer 14 is bonded to the substrate 12. Subsequently, when using the skin-adhesive sheet 10, the release layer 14 is peeled off from the adhesive layer 13.

[0032] The constituent material of the adhesive layer 13 may be a urethane-based adhesive, an acrylic-based adhesive, a silicone-based adhesive, or a rubber-based adhesive. The constituent material of the adhesive layer 13 may be a two-component mixture type or a one-component type. The constituent material of the adhesive layer 13 may be a two-component type consisting of a solvent-based urethane-based adhesive and a curing agent.

[0033] The material of the surface of the release layer 14 that is in contact with the adhesive layer 13 may be a silicone-based release agent or a fluorine-based release agent. The release layer 14 may be a multilayer sheet comprising a base film made of polyolefin resin or polyester resin and a release layer coated on the surface of the base film, or it may be a single-layer sheet.

[0034] The thickness of the release layer 14 may be 10 μm or more and 350 μm or 50 μm or more and 200 μm or less. The release layer 14 may be a single-layer sheet or a multi-layer sheet. If the release layer 14 is a multi-layer sheet, the constituent materials of each layer laminated via the adhesive layer may be different materials or the same material.

[0035] As shown in Figure 4, the constituent material of the display layer 11 includes a coloring agent. The coloring agent may be an aqueous pigment ink, an oil-based pigment ink, a thermal pigment, a thermal dye, or a toner. The coloring agent may be colorless or colored. The coloring agent may also be one that develops color or changes color in response to changes in pH, temperature, light exposure, or water contact, for example, a leuco dye.

[0036] The display layer 11 may be formed on the base material 12 by a writing instrument when the adhesive layer 13 is attached to the skin. The display layer 11 may be formed on the base material 12 by a printing press or the like when the skin-attachable sheet 10 is manufactured. The printing method may be gravure printing, screen printing, inkjet printing, etc. The display layer 11 may be drawn on by a UV laser after the heat-sensitive layer has been formed.

[0037] The information displayed on the display layer 11 may be at least one selected from the group consisting of characters, figures, symbols, patterns, and illustrations. The information displayed on the display layer 11 may be indicated by the portion of the surface of the substrate 12 where the display layer 11 is located, or by the portion of the surface of the substrate 12 where the display layer 11 is left open.

[0038] [Examples] Examples and comparative examples will be described with reference to Figures 1 to 5. [Example 1] A biaxially oriented polypropylene (OPP) film (manufactured by Futamura Chemical Co., Ltd., FOR-MP, 40 μm thick) was prepared as a carrier sheet 15, having a pair of opposing surfaces in the thickness direction, one of which was a matte surface and the other a gloss surface. A coating solution was prepared as the first coating solution by mixing a first aqueous polyurethane containing an ether-based polyol (manufactured by Mitsui Chemicals, Inc., Takelac WS-6021 (Takelac is a registered trademark)) and a second aqueous polyurethane containing an ether-based polyol (manufactured by Mitsui Chemicals, Inc., Takelac W-6020) in equal weight ratios. The first coating solution was applied to the matte surface of the carrier sheet 21, and then the first coating solution was dried. Subsequently, the first coating film was aged at room temperature for 48 hours to obtain a substrate 12 with a thickness of 15 μm.

[0039] A release film consisting of a PET film and a release layer (manufactured by Toray Film Processing Co., Ltd., Therapiel BX8A (Therapiel is a registered trademark), 75 μm thick) was prepared as the release layer 14. In addition, a urethane-based adhesive (manufactured by Toyo Chem Co., Ltd., SP-205) and a curing agent (manufactured by Toyo Chem Co., Ltd., T-501B) were prepared.

[0040] Next, a hardening agent was added to the main component, and the mixture of the main component and the hardening agent was stirred to obtain a second coating solution for forming the adhesive layer 13. Then, the second coating solution was applied to the release layer of the release layer 14, and the second coating solution was dried to obtain an adhesive layer 13 having a thickness of 15 μm.

[0041] Next, the adhesive layer 13 and the second surface 12B of the substrate 12 were bonded together to obtain a laminate as shown in Figure 1, in which the adhesive layer 13 and the substrate 12 were sandwiched between the carrier sheet 15 and the release layer 14. The laminate was then aged at 50°C for 72 hours.

[0042] Furthermore, the carrier sheet 15 was peeled off to expose the first surface 12A, which is the release surface. Then, a design was drawn on the first surface 12A using a blue marker containing water-based pigment ink (PROCKEY Blue, manufactured by Mitsubishi Pencil Co., Ltd.) to form the display layer 11. This resulted in a skin-adhesive sheet 10 in which the display layer 11, substrate 12, adhesive layer 13, and release layer 14 were laminated in that order.

[0043] When applying to the skin, the release layer 14 is peeled off the skin application sheet 10. This yields the sheet body 10A as shown in Figure 4. [Example 2] In Example 1, when preparing the first coating solution, the second aqueous polyurethane was omitted, and only the first aqueous polyurethane (Takelac WS-6021, manufactured by Mitsui Chemicals, Inc.) was added. Otherwise, the skin-adhesive sheet 10 of Example 2 was obtained by the same method as in Example 1.

[0044] [Example 3] In Example 2, when bonding the adhesive layer 13 to the substrate 12, the first surface 12A was exposed by peeling the carrier sheet 15 from the substrate 12, and then the adhesive layer 13 and the first surface 12A of the substrate 12 were bonded together. This resulted in a laminate in which the substrate 12 with its second surface 12B exposed as the outermost surface, the adhesive layer 13, and the release layer 14 were laminated together. The laminate was then aged at 50°C for 72 hours.

[0045] Then, a pattern was drawn on the exposed second surface 12B to form the display layer 11. Otherwise, the skin-adhesive sheet 10 of Example 3 was obtained by the same method as in Example 2. [Example 4] In Example 2, a thermal ink containing a leuco dye was used to form the display layer 11. A pattern was drawn on the thermal layer formed by the thermal ink using a UV laser. Otherwise, the skin-adhesive sheet 10 of Example 4 was obtained by the same method as in Example 2.

[0046] [Comparative Example 1] In Example 1, when forming the substrate 12, an aqueous urethane coating was applied to the glossy surface of the OPP film. Otherwise, the skin-adhesive sheet 10 of Comparative Example 1 was obtained by the same method as in Example 1.

[0047] When applying to the skin, the release layer 14 is peeled off the skin application sheet 10. This yields the sheet body 10A as shown in Figure 5. [Comparative Example 2] In Example 1, when forming the substrate 12, a coating solution prepared by mixing urethane ink (V351UR-T medium, manufactured by artience Co., Ltd.) and a curing agent (LPNYB additive, manufactured by artience Co., Ltd.) was applied to the gloss surface of the OPP film. Otherwise, the skin-adhesive sheet of Comparative Example 2 was obtained by the same method as in Example 1.

[0048] [Comparative Example 3] In Example 1, when forming the substrate 12, a coating solution made by mixing water-based polyurethane (Dainichi Seika Kogyo Co., Ltd., D-6300) and a curing agent (Nisshinbo Chemical Co., Ltd., V-02) was applied to the gloss surface of the OPP film. Otherwise, the skin-adhesive sheet 10 of Comparative Example 3 was obtained by the same method as in Example 1.

[0049] [Comparative Example 4] The polyurethane film was exposed by peeling off the PP film from the surface of a commercially available first film dressing (Nichiban Co., Ltd., Catery Plus Roll (Catery Plus is a trademark)). Then, a display layer 11 was formed by drawing a pattern on the exposed surface of the polyurethane film using a marker containing water-based pigment ink (Mitsubishi Pencil Co., Ltd., PROCKEY Blue). This resulted in a laminate in which the display layer 11, the polyurethane film, and the adhesive layer 13 were laminated together.

[0050] [Comparative Example 5] The laminate of Comparative Example 5 was obtained by the same method as in Comparative Example 4, except that a commercially available second film dressing (Tegaderm Smooth Film Roll, manufactured by 3M Japan Ltd. (Tegaderm is a trademark)) was used.

[0051] [Evaluation Method] [Wetting tension] The wet tensile strength of the surface of the substrate 12 in contact with the display layer 11 was measured according to the method conforming to JIS K 6768:1999, "Plastics - Films and Sheets - Wetting Tension Test Method".

[0052] First, 10 cm square test pieces were cut from the skin-adhesive sheets 10 of each example and comparative example. Next, 2 to 3 drops of the wettability test mixture (manufactured by Fujifilm Wako Pure Chemical Industries) were dropped onto the test piece. Using a cotton swab, the dropped wettability test mixture was spread over the entire test piece, and then observed visually. After 2 seconds had elapsed since application of the wettability test mixture, it was judged that the coating was "wet" if it had not broken, and that it was "not wet" if it had broken.

[0053] [Arithmetic mean roughness Sa] The arithmetic mean roughness Sa of the surface of the substrate 12 in contact with the display layer 11 was measured according to the method conforming to the "Surface properties parameters" of ISO 25178-2:2012. For Examples 1-2 and 4, the surface of the carrier sheet 15 that was in contact with the substrate 12 was measured. For Example 3 and Comparative Examples 1-5, the surface of the substrate 12 in contact with the display layer 11 was measured. First, 30 mm square test pieces were cut from the skin-adhesive sheets 10 of each example and comparative example. Next, measurements were performed using a 3D measuring laser microscope (Olympus Corporation, LEXT OLS-4000) equipped with a 50x objective lens, under conditions of a cutoff value of 80 μm.

[0054] [Presence or absence of bleeding or repulsion during coating of the display layer] For each example and comparative example, the presence or absence of ink bleeding and repulsion was visually evaluated when applying the display layer 11. "◎" indicates that neither ink bleeding nor repulsion was observed. "○" indicates that there was slight ink bleeding, but no ink repulsion was observed. "×" indicates that ink repulsion was observed. When ink repulsion occurs, the ink does not adhere to the surface, so bleeding cannot be judged.

[0055] ◎: Neither bleeding nor repelling occurs. ○: There is slight bleeding, but no repelling. ×: It has a repulsive effect.

[0056] [Ink Fixation Test] The formed display layer 11 was dried. The drying time was 30 minutes when using a water-based pigment marker, which is an example of a water-based ink, and 1 minute when using a thermal ink. Then, cellophane adhesive tape (manufactured by Nichiban Co., Ltd., Cellotape®), which conforms to JIS standards, was attached to the dried display layer 11 and adhered tightly. Subsequently, after peeling it off at 180 degrees, the condition of the display layer 11 was visually evaluated. "◎" indicates a state where no areas of ink peeling were observed. "○" indicates a state where there are areas of ink peeling, but the area is small. "×" indicates a state where there are areas of ink peeling, and the area is large.

[0057] ◎: No areas where the ink has peeled off. ○: There are a few areas where the ink has peeled off. ×: There are areas where the ink has peeled off significantly.

[0058] [Wipe resistance test] The adhesion of the display layer 11 was tested, particularly whether the ink, once fixed to the surface, would detach due to friction or surface wetting. Specifically, similar to the ink adhesion test, the formed display layer 11 was dried. The drying time was 30 minutes for a water-based pigment marker (an example of a water-based ink) and 1 minute for a thermal ink. Next, the display layer 11 was rubbed 10 times using a wet wipe (Daio Paper Corporation, Elleair non-alcohol disinfecting towel). The condition of the rubbed display layer 11 was then visually evaluated. "◎" indicates minimal peeling and disappearance of the display layer 11. "○" indicates peeling and disappearance of the display layer 11 was observed in approximately 50% of the rubbed area. "×" indicates almost complete peeling or disappearance of the display layer 11. ◎: Peeling and disappearance of display layer 11 are minor. ○: Approximately 50% of the display layer 11 is peeling or disappearing. ×: The display layer 11 is almost completely peeled off or has disappeared.

[0059] [Skin conformity test] A 30mm square test piece was cut from the skin-adhesive sheet 10 of each example and each comparative example. Next, the release layer 14 of the test piece was peeled off from the adhesive layer 13 and then applied to the forearm. After that, the sheet body 10A was visually evaluated to see whether it followed the skin when the applied area was pinched with fingers or when the arm was moved. "◎" indicates that the sheet body 10A follows the skin and does not peel off. "○" indicates that the sheet body 10A follows the skin, but the skin feels tight, and the sheet body 10A does not peel off. "×" indicates that the sheet body 10A does not follow the skin and a part of the sheet body 10A has peeled off.

[0060] ◎: It adheres well and does not peel off. ○: It conforms to the surface, but there's a slight feeling of tightness. It doesn't peel off. ×: It does not conform to the surface, and peeling occurs in part of the sheet body 10A.

[0061] [Evaluation Results] Refer to Figure 6 to explain the evaluation results. As shown in Figure 6, the wetting tension of the surface of the substrate 12 in contact with the display layer 11 was found to be 65 mN / m in Example 1, 73 mN / m in Examples 2 and 4, and 50 mN / m in Example 3. Furthermore, the wetting tensions of Comparative Examples 1 to 5 were all less than or equal to the wetting tension of each example, and Comparative Example 5 had the smallest wetting tension.

[0062] The arithmetic mean roughness Sa of the surface of the substrate 12 in contact with the display layer 11 was found to be 0.8 μm in Examples 1, 2, and 4, and 0.4 μm in Example 3. Furthermore, it was found to be 0.03 μm in Comparative Examples 1 to 3, 0.7 μm in Comparative Example 4, and 0.1 μm in Comparative Example 5.

[0063] In all of the examples, the evaluation of bleeding and repulsion during the coating of the display layer was "◎", meaning that neither bleeding nor repulsion of the ink was observed. Comparative Examples 1 to 3, with an arithmetic mean roughness Sa of less than 0.2 μm, and Comparative Example 4, with a wetting tension of less than 50 mN / m, all received "○", meaning that there was slight bleeding, but no repulsion was observed. Comparative Example 5, with a wetting tension of less than 30 mN / m, received "×", meaning that repulsion was observed.

[0064] In the evaluation of ink adhesion, Examples 1 and 2, and Comparative Example 1 received a "◎" rating, meaning no areas of ink peeling were observed. Examples 4 and Comparative Example 4 received a "○" rating, meaning slight areas of ink peeling were observed. Comparative Examples 2, 3, and 5 received a "×" rating, meaning areas of significant ink peeling were observed.

[0065] The evaluation of resistance to wiping was "◎" in Examples 2 and 4, meaning that peeling and disappearance of the display layer 11 were minor. Examples 1, 3, and Comparative Example 4 were "○", meaning that peeling and disappearance of the display layer 11 were observed in about 50% of the rubbed area. In Comparative Examples 1 to 3 and Comparative Example 5, the evaluation of resistance to wiping was "×", meaning that almost all of the display layer 11 peeled or disappeared.

[0066] In terms of conformability to the skin, Examples 2 to 4, Comparative Examples 1 to 2, and Comparative Example 4 all received a "◎" rating, meaning they conformed well and no peeling was observed. In Example 1 and Comparative Example 5, the rating was "○", meaning they conformed well, although there was a slight feeling of tightness, but no peeling was observed. On the other hand, Comparative Example 3 received a "×" rating, meaning it did not conform well, and some peeling was observed on a portion of the sheet body 10A.

[0067] As explained above, the following effects can be obtained by using the skin-adhesive sheet 10. (1) The wetting tension on the surface of the substrate 12, calculated in accordance with JIS K 6768:1999, is 50 mN / m or more, and the arithmetic mean roughness Sa, calculated in accordance with ISO 25178-2:2012, is 0.2 μm or more. As a result, both bleeding and repulsion of the display layer 11 onto the substrate 12 containing polyurethane resin are suppressed, and the display layer 11 is fixed. Furthermore, even if friction occurs against the display layer 11 or wetting occurs on the surface of the substrate 12, the display layer 11 will not easily detach.

[0068] (2) The polyurethane resin of the base material 12 is an aqueous polyurethane containing an ether polyol. Therefore, the display layer 11 can be fixed to the base material 12 containing the aqueous polyurethane containing an ether polyol.

[0069] (3) The 100% modulus of the sheet body 10A is 2.0 MPa or less. Therefore, the conformability of the skin-adhesive sheet 10 to the skin is improved. (4) The coloring agent that forms the display layer 11 is a heat-sensitive material. Therefore, the display layer 11 that responds to temperature changes is fixed in place.

[0070] (5) The carrier sheet 15 has a lower tensile strength than the base material 12, and the matte surface of the carrier sheet 15 is in contact with the surface of the base material 12. Furthermore, since the thickness of the base material 12 is between 5 μm and 30 μm, the roughness described in (1) above is easily formed on the base material 12 due to the irregularities of the matte surface. As a result, the variation in the irregularities on the surface of the base material 12, and consequently the variation in the arithmetic mean roughness Sa, is suppressed by the amount that the carrier sheet 15 has a lower tensile strength than the base material 12.

[0071] (6) The same effect as in (5) above can also be obtained if the peeled surface of the substrate 12 that has been peeled off from the matte surface of the carrier sheet 15 is the surface on which the display layer 11 is formed. (7) A comparison of Example 2 with other examples shows that when the 100% modulus is 2.0 MPa or less and the arithmetic mean roughness Sa is 0.6 μm or more, which is the intermediate value between Example 2 and other examples, the effectiveness of obtaining the effects described in (1) and (3) above is further enhanced. In particular, the peeling of the display layer 11 by cellophane adhesive tape and peeling by wiping are suppressed.

[0072] (8) When the polyurethane resin of the base material 12 is an aqueous polyurethane containing an ether polyol, the adhesive layer 13 contains a urethane adhesive, and the display layer 11 contains an aqueous ink, the effectiveness of obtaining the effects in accordance with (2) above is increased.

[0073] [Example of changes] The above embodiment can be implemented with the following modifications. The above embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0074] [Example of first change] Referring to Figures 7 to 9, the first example of modification of the skin-adhesive sheet will be explained. As shown in Figure 7, the skin-adhesive sheet 20 may be a laminate comprising a carrier sheet 21, a base material 12, an adhesive layer 13, and a release layer 14. The base material 12 and the adhesive layer 13 constitute the sheet body 20A. The sheet body 20A is located between the carrier sheet 21 and the release layer 14. The sheet body 20A is in contact with the carrier sheet 21 and has a higher tensile strength than the carrier sheet 21 and the release layer 14. The adhesive layer 13 is in contact with the release layer 14. The adhesive layer 13 is attached to the skin after the release layer 14 has been peeled away from the adhesive layer 13.

[0075] As shown in Figure 8, in the first modification example, the area of ​​the carrier sheet 21 may be larger than the area of ​​the sheet body 20A. The area within the carrier sheet 21 that does not overlap with the sheet body 20A is the first area 21R1. The area within the carrier sheet 21 that overlaps with the sheet body 20A is the second area 21R2. The carrier sheet 21 has a cut 21A. In the example shown in Figure 8, the carrier sheet 21 has only one cut 21A. When viewed from a viewpoint opposite to the plane on which the carrier sheet 21 extends, the cut 21A extends from the portion of the outer edge 21E of the carrier sheet 21 that is included in the first area 21R1 toward the sheet body 20A, beyond the boundary 21B between the first area 21R1 and the second area 21R2.

[0076] In the first modification example, the slit 21A comprises a base end 21AP and a tip end 21AD. The base end 21AP of the slit 21A is located in the portion of the outer edge 21E of the carrier sheet 21 that is included in the first region 21R1. In contrast, the tip end 21AD of the slit 21A is located in the portion of the outer edge 21E of the carrier sheet 21 that is included in the second region 21R2. The tip end 21AD of the slit 21A may be located in the region of the second region 21R2 of the carrier sheet 21 that is inside the outer edge 21E.

[0077] In other words, in the example shown in Figure 8, the carrier sheet 21 has a rectangular shape, and the cut 21A has a length that extends across the entire short side of the carrier sheet 21. Alternatively, the cut 21A may have a length that extends across the entire first region 21R1 and partway through the second region 21R2 in the short side direction of the carrier sheet 21.

[0078] As shown in Figure 8, in the first modified example, the cut 21A may be straight. Alternatively, the cut 21A may be curved or folded. If the cut 21A is folded, the cut 21A may have only one bend or two or more bends.

[0079] Figure 9 is a cross-sectional view including a portion of the carrier sheet 21 and a portion of the base material 12 in the first modified example. Figure 9 is also a cross-sectional view along a plane including the cut 21A in the carrier sheet 21.

[0080] In the example shown in Figure 9, the cut 21A may have a depth D1 that reaches only a portion of the carrier sheet 21 in the thickness direction. Alternatively, the cut 21A may have a depth D1 that extends over the entire carrier sheet 21 in the thickness direction. If the cut 21A has a depth D1 that reaches only a portion of the carrier sheet 21 in the thickness direction, the carrier sheet 21 has a remaining portion 21RE that is connected to the cut 21A in the thickness direction of the carrier sheet 21. The remaining portion 21RE of the carrier sheet 21 has a remaining thickness TR1 obtained by subtracting the depth D1 of the cut 21A from the thickness T of the carrier sheet 21.

[0081] In the first modification example, the gap 21A may consist of a first part 21AA and a second part 21AB. The first part 21AA is the portion of the gap 21A located in the first region 21R1 of the carrier sheet 21. The second part 21AB is the portion of the gap 21A located in the second region 21R2 of the carrier sheet 21. In the example shown in Figure 9, the depth of the first part 21AA is equal to the depth of the second part 21AB. The depth of the first part 21AA may be different from the depth of the second part 21AB.

[0082] In the first modification example, the depth D1 of the cut 21A may satisfy the following formula when the thickness of the carrier sheet 21 is T. 1 / 4T ≤ D1 ≤ T From the viewpoint of facilitating the peeling of the carrier sheet 21 starting from the cut 21A, it is preferable that the depth D1 of the cut 21A be deep. Therefore, the lower limit of the depth D1 may be 1 / 2T or 3 / 4T. From the viewpoint of preventing the base material 12 from being cut during the manufacture of the skin-adhesive sheet 20, and from preventing foreign matter from reaching the base material 12 through the cut 21A, it is preferable that the depth D1 of the cut 21A be shallow. Therefore, the depth D1 may be less than T. Also, the upper limit of the depth D1 may be 3 / 4T or 1 / 2T.

[0083] In the first modification example, the depth of the cut 21A in the portion of the carrier sheet 21 that overlaps with the sheet body 20A may be shallower than the depth of the portion of the carrier sheet 21 that does not overlap with the sheet body 20A. That is, the depth of the first portion 21AA of the cut 21A may be deeper than the depth of the second portion 21AB of the cut 21A.

[0084] In the first modification example, the wetting tension calculated on the surface of the substrate 12 in accordance with JIS K 6768:1999 may be less than 50 mN / m. In the first modification example, the arithmetic mean roughness Sa calculated on the surface of the substrate 12 in accordance with ISO 25178-2:2012 may be less than 0.2 μm.

[0085] [Other examples of changes] The area of ​​the carrier sheet 15 may be approximately the same as the area of ​​the substrate 12, or approximately the same as the area of ​​the adhesive layer 13. The thickness of the carrier sheet 15 may be less than 10 μm or greater than 400 μm.

[0086] The thickness of the substrate 12 may be less than 5 μm or greater than 30 μm. The thickness of the release layer 14 may be less than 10 μm or greater than 350 μm. The polyurethane resin of the base material 12 may be an aqueous polyurethane containing an ether polyol, the adhesive layer 13 may contain a urethane adhesive, and the display layer 11 may contain an oil-based ink. In this modified example as well, the effects of (1) described above, corresponding to the wetting tension and arithmetic mean roughness Sa, can be obtained.

[0087] The skin-adhesive sheet 10 may omit at least one of the display layer 11, the release layer 14, and the carrier sheet 15.

[0088] [Note] The technical ideas derived from the above embodiments and their modifications are noted below. [Note 1] Carrier seat and, The delamination layer, The device comprises a sheet body located between the carrier sheet and the release layer, The aforementioned seat body is A substrate having a higher tensile fracture elongation than the carrier sheet and the release layer, The release sheet is in contact with an adhesive layer, The area of ​​the carrier sheet is larger than the area of ​​the sheet body. The carrier sheet includes a first region which is a region that does not overlap with the sheet body, and a second region which is a region that overlaps with the sheet body. The carrier sheet, when viewed from a viewpoint opposite to the plane on which the carrier sheet extends, has a cut that extends from the portion of the outer edge of the carrier sheet included in the first region toward the sheet body, beyond the boundary between the first region and the second region, Of the aforementioned cuts, the depth in the second region is shallower than the depth in the first region. The depth D1 of the cut satisfies the following equation using the thickness T of the carrier sheet: 1 / 4T ≤ D1 ≤ T Skin-adhesive sheet.

[0089] According to the above note 1, the depth of the cut extending from outside the sheet body to inside the sheet body is within the range of 1 / 4T to T. Therefore, whether the surface wetting tension is specified or not, it is easy to peel the carrier sheet from the substrate starting from the cut. Whether the surface arithmetic mean roughness Sa is specified or not, it is easy to peel the carrier sheet from the substrate starting from the cut.

[0090] Furthermore, the portion of the cut located on the sheet body does not penetrate the carrier sheet. Therefore, regardless of whether or not there is a display layer, the cutting of the base material together with the carrier sheet is suppressed during the manufacturing of the skin-adhesive sheet, and foreign matter is prevented from reaching the base material through the cut before the skin-adhesive sheet is used.

[0091] [Note 2] The substrate further comprises a display layer located on the surface opposite to the surface facing the adhesive layer, containing a coloring agent and configured to display predetermined information. Skin-adhesive sheet as described in Appendix 1. [Explanation of Symbols]

[0092] 10,20…Skin adhesive sheets 10A, 20A... Sheet body 11…display layer 11A, 21A... gap 12...Base material 12A…1st surface 12B…Second surface 13…Adhesive layer 14… Exfoliation layer 15, 21… Carrier sheet 21AA…Part 1 21AB…Second part 21AD…Tip 21AP…Proximal end 21B…boundary 21E...Outer edge 21R1…First area 21R2…Second area 21RE…Remainder T...thickness D1... Depth TR1…Residual thickness

Claims

1. A substrate containing polyurethane resin, It comprises an adhesive layer that can be attached to the skin, The substrate is one on which a display layer containing a coloring agent configured to display predetermined information is formed on the surface opposite to the surface facing the adhesive layer. The wetting tension on the aforementioned surface, calculated in accordance with JIS K 6768:1999, is 50 mN / m or more. The arithmetic mean roughness Sa of the aforementioned surface, calculated in accordance with ISO 25178-2:2012, is 0.2 μm or greater. Skin-adhesive sheet.

2. The polyurethane resin is an aqueous polyurethane containing an ether-based polyol. The skin-adhesive sheet according to claim 1.

3. The sheet body comprises the aforementioned substrate and the aforementioned adhesive layer, The 100% modulus of the sheet body is 2.0 MPa or less. The skin-adhesive sheet according to claim 1.

4. The aforementioned display layer is further provided, The aforementioned coloring agent is a heat-sensitive material. The skin-adhesive sheet according to claim 1.

5. The carrier sheet has a matte surface and a lower tensile strength than the base material, The mat surface is in contact with the surface of the substrate that is facing the adhesive layer. The thickness of the substrate is 5 μm or more and 30 μm or less. The skin-adhesive sheet according to claim 1.

6. The surface of the substrate is a peeled surface that has been peeled from the mat surface of a carrier sheet having a lower tensile break elongation than the substrate. The thickness of the substrate is 5 μm or more and 30 μm or less. The skin-adhesive sheet according to claim 1.

7. The arithmetic mean roughness Sa on the aforementioned surface is 0.6 μm or greater. The skin-adhesive sheet according to claim 3.

8. The aforementioned display layer is further provided, The polyurethane resin is an aqueous polyurethane containing an ether-based polyol. The adhesive layer contains a urethane-based adhesive, The display layer contains water-based ink A skin-adhesive sheet according to any one of claims 1 to 7.

9. Carrier seat and, The delamination layer, The device comprises a sheet body located between the carrier sheet and the release layer, The aforementioned seat body is The substrate comprises the polyurethane resin and has a higher tensile elongation than the carrier sheet and the release layer, The adhesive layer, which is in contact with the release layer and adheres to the skin, The area of ​​the carrier sheet is larger than the area of ​​the sheet body. The carrier sheet includes a first region which is a region that does not overlap with the sheet body, and a second region which is a region that overlaps with the sheet body. The carrier sheet, when viewed from a viewpoint opposite to the plane on which the carrier sheet extends, has a cut that extends from the portion of the outer edge of the carrier sheet included in the first region toward the sheet body, beyond the boundary between the first region and the second region, Of the aforementioned cuts, the depth in the second region is shallower than the depth in the first region. The depth D1 of the cut satisfies the following equation using the thickness T of the carrier sheet: 1 / 4T ≤ D1 ≤ T A skin-adhesive sheet according to any one of claims 1 to 7.

Images