Skin patch sheet and production method thereof

Abstract

To provide a skin patch sheet in which the capability to absorb ultraviolet rays is readily maintained at positions to which ultraviolet absorbing capability has been imparted by the user, and the sheet body is prevented from appearing to lift off from the skin, and a method for producing the skin patch sheet.SOLUTION: A skin patch sheet 10 comprises: a substrate layer 11 containing an aqueous polymer compound and at least one of lignin sulfonate and kraft lignin; and an adhesive layer 12 laminated on the substrate layer 11. The adhesive layer 12 is located on the side opposite to the surface facing the substrate layer 11 and includes an adhesive surface 12S for skin attachment. In a sheet body 10B including the substrate layer 11 and the adhesive layer 12, the transmittance throughout the full range of 280 nm to 400 nm is 80% or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a skin patch sheet and a method for manufacturing the skin patch sheet.

Background Art

[0002] Ultraviolet rays include ultraviolet B rays (UVB) in the wavelength range of 280 nm or more and less than 320 nm, and ultraviolet A rays (UVA) in the wavelength range of 320 nm or more and 400 nm or less. When the skin is irradiated with UVB, inflammation occurs in the skin. UVA reaches deeper into the skin than UVB. When the skin is irradiated with ultraviolet rays, the skin gets sunburned, and as a result, the skin ages. In order to suppress aging due to sunburn, cosmetics applied to the skin are used (for example, see Patent Document 1). Cosmetics are usually liquid. Liquid cosmetics include, for example, sunscreen creams and sunscreen sprays.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, since liquid cosmetics get smeared due to sweating and sebum, it is difficult to maintain the state where the cosmetics are applied to the skin. In addition, when the color of the liquid cosmetics is greatly different from the color of the skin, since the cosmetics look floating on the skin and it is easy for others to recognize that the cosmetics are applied, the user may avoid applying the cosmetics.

Means for Solving the Problems

[0005] The skin patch for solving the above problems includes an aqueous polymer compound, a base material layer containing at least one of lignin sulfonate and kraft lignin, and an adhesive layer laminated on the base material layer and attached to the skin. In the sheet body including the base material layer and the adhesive layer, the transmittance in the entire range of 280 nm or more and 400 nm or less is 80% or less.

[0006] According to the above skin patch, since the base material layer and the adhesive layer have a solid state, even when the user touches the sheet body attached to the skin, compared with a liquid cosmetic, the position of the sheet body relative to the skin is less likely to shift or the sheet body is less likely to be removed from the skin. As a result, the ultraviolet absorption ability of at least one of lignin sulfonate and kraft lignin contained in the base material layer is likely to be maintained at the position where the user attached the sheet body. In addition, since the color exhibited by lignin sulfonic acid or kraft lignin does not greatly deviate from the color exhibited by the skin, it is possible to suppress the sheet body from appearing to float from the skin.

[0007] In the above skin patch, the lignin sulfonate or the kraft lignin is an ultraviolet absorber, the thickness of the base material layer is 5 μm or more and 30 μm or less, and the base material layer may contain 2% by mass or more and 20% by mass or less of the ultraviolet absorber.

[0008] According to the above skin patch, it is possible to enhance the certainty of obtaining the ultraviolet absorption ability by the ultraviolet absorber contained in the base material layer.

[0009] In the above skin patch, the lignin sulfonate is included, the lignin sulfonate is a sodium salt, and the lignin purity of the lignin sulfonate may be 40% or more and 95% or less. According to the above skin patch, it is possible to enhance the certainty of forming a base material layer containing lignin sulfonate.

[0010] In the above skin patch, the breaking strength of the sheet body is 5 N / mm 2The above may be sufficient. According to the above skin patch sheet, the sheet body can have a sufficiently high breaking strength to withstand stretching for following the skin.

[0011] In the above skin patch sheet, a protective layer in contact with the base material layer is further provided on the side opposite to the adhesive layer with respect to the base material layer, and the peel strength between the base material layer and the protective layer may be 0.2 N / 25 mm or less. According to the above skin patch sheet, it is easy to peel the protective layer from the base material layer.

[0012] In the above skin patch sheet, the aqueous polymer compound may be a polyurethane resin. According to the above skin patch sheet, it is possible to obtain a base material layer having high followability to the skin. [Advantages of the Invention]

[0013] According to the skin patch sheet of the present disclosure, the ultraviolet absorption ability is likely to be maintained at the position where the user imparts the ultraviolet absorption ability, and the sheet body can be suppressed from appearing to float from the skin. [Brief Description of the Drawings]

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

[0015] With reference to FIGS. 1 to 3, an embodiment of the skin patch sheet will be described. [Skin Patch Sheet] Referring to FIGS. 1 and 2, a skin patch sheet will be described. As shown in FIG. 1, the skin patch sheet 10 includes a sheet body 10B. The sheet body 10B includes a base material layer 11 and an adhesive layer 12. The adhesive layer 12 is laminated on the base material layer 11. The adhesive layer 12 has an adhesive surface 12S on the surface opposite to the surface facing the base material layer 11 and is attached to the skin. In the present embodiment, since the sheet body 10B is composed of the base material layer 11 and the adhesive layer 12, the surface of the adhesive layer 12 opposite to the surface in contact with the base material layer 11 is the adhesive surface 12S. The sheet body 10B may include a printing layer located between the base material layer 11 and the adhesive layer 12, for example, in the thickness direction of the skin patch sheet 10.

[0016] The sheet body 10B satisfies the following conditions 1 and 2. (Condition 1) The base material layer 11 contains an aqueous polymer compound and lignin sulfonate or kraft lignin. (Condition 2) The transmittance in the entire range of 280 nm or more and 400 nm or less is 80% or less.

[0017] That is, in the sheet body 10B, the transmittance of each wavelength included in the ultraviolet wavelength range of 280 nm or more and 400 nm or less is 80% or less.

[0018] Since the base material layer 11 and the adhesive layer 12 are in a solid state, even when the user touches the sheet body 10B attached to the skin, compared with a liquid cosmetic, it is difficult for the position of the sheet body 10B relative to the skin to shift or for the sheet body 10B to be removed from the skin. Thereby, the ultraviolet absorption ability of the lignin sulfonate or kraft lignin contained in the base material layer 11 is likely to be maintained at the position where the user has attached the sheet body 10B. In addition, since the color exhibited by lignin sulfonic acid or kraft lignin does not greatly deviate from the color exhibited by the skin, it is suppressed that the sheet body 10B looks floating from the skin.

[0019] In the present disclosure, the aqueous polymer compound contained in the base material layer 11 means a polymer compound remaining after evaporating water, which is a dispersion medium, from an aqueous polymer compound that is an aqueous dispersion of the polymer compound used in the production of the base material layer 11. On the other hand, the aqueous polymer compound used in the production of the base material layer 11 means an aqueous dispersion of the polymer compound, in other words, a polymer compound dispersed in water.

[0020] The skin patch 10 further includes a protective layer 13 and a release layer 14. The protective layer 13 is in contact with the base material layer 11 on the side opposite to the adhesive layer 12 with respect to the base material layer 11. The release layer 14 is in contact with the adhesive layer 12 on the side opposite to the base material layer 11 with respect to the adhesive layer 12. The skin patch 10 may satisfy at least one of the following Condition 3 and Condition 4.

[0021] (Condition 3) The breaking strength of the sheet body 10B is 5 N / mm 2 or less. (Condition 4) The peel strength between the base material layer 11 and the protective layer 13 is 0.2 N / 25 mm or less.

[0022] When the skin patch 10 satisfies Condition 3, the sheet body 10B can have a sufficiently high breaking strength to withstand stretching for following the skin. When the skin patch 10 satisfies Condition 4, it is easy to peel the protective layer 13 from the base material layer 11. Each of the breaking strength and the peel strength is a value measured by a method conforming to JIS K 7127:1999 "Plastics - Test method for tensile properties - Part 3: Test conditions for films and sheets".

[0023] FIG. 2 shows a planar structure in an example of the skin patch 10 as viewed from a perspective facing the plane on which the skin patch 10 spreads. In the example shown in FIG. 2, the outer shape of the skin patch sheet 10 has a rectangular shape. The outer shape of the protective layer 13 coincides with the outer shape of the skin patch sheet 10. The base material layer 11, the adhesive layer 12, and the release layer 14 are smaller than the protective layer 13 and have the same shape and size as each other. The protective layer 13 includes a first region 13R1 and a second region 13R2. Each of the regions 13R1 and 13R2 has a rectangular shape extending along the longitudinal direction of the skin patch sheet 10, and the first region 13R1 and the second region 13R2 are arranged along the short side direction of the skin patch sheet 10. Among the protective layer 13, the first region 13R1 is a region that does not overlap with the base material layer 11, while the second region 13R2 is a region that overlaps with the base material layer 11.

[0024] The protective layer 13 includes two cuts 13B. The protective layer 13 may include only one cut 13B or three or more cuts 13B. The cut 13B is located in the first region 13R1 of the protective layer 13 and extends from the outer edge 10E of the skin patch sheet 10 toward the second region 13R2, but does not reach the second region 13R2. In the thickness direction of the protective layer 13, the cut 13B may or may not penetrate the protective layer 13. From the viewpoint of facilitating tearing of the protective layer 13 starting from the cut 13B, it is preferable that the depth of the cut 13B is deeper, and it is more preferable that the cut 13B penetrates the protective layer 13.

[0025] Each cut 13B extends along the short side direction of the skin patch sheet 10. The two cuts 13B are arranged along the longitudinal direction. The distance D13B between the cuts 13B in the longitudinal direction may be, for example, 3 mm or more and 40 mm or less. Thereby, the portion located between the cuts 13B is easy to grip. The center of the skin patch sheet 10 in the longitudinal direction may be located between the cuts 13B. Thereby, by cutting the protective layer 13 along the cut 13B, it is possible to cut the protective layer 13 at substantially the center in the longitudinal direction.

[0026] The outer shape of the skin patch 10 may have a shape other than a rectangular shape. For example, the outer shape of the skin patch 10 may have a triangle, a square, a polygon with five or more sides, a circle, an ellipse, or the like.

[0027] Hereinafter, each layer included in the skin patch 10 will be described in more detail. [Base material layer] The aqueous polymer compound included in the base material layer 11 may be, for example, a polyurethane resin. By including the polyurethane resin in the base material layer 11, it is possible to obtain the base material layer 11 having high followability to the skin.

[0028] The base material layer 11 preferably satisfies the following conditions 5 and 6. (Condition 5) The thickness of the base material layer 11 is 5 μm or more and 30 μm or less. (Condition 6) The base material layer 11 contains 2% by mass or more and 20% by mass or less of an ultraviolet absorber. Lignin sulfonate or kraft lignin is the ultraviolet absorber.

[0029] According to the skin patch satisfying conditions 5 and 6, it is possible to enhance the certainty of obtaining the ultraviolet absorption ability by the ultraviolet absorber included in the base material layer 11.

[0030] When the base material layer 11 contains lignin sulfonate, the base material layer 11 preferably satisfies the following conditions 7 and 8. (Condition 7) The lignin sulfonate is a sodium salt. (Condition 8) The lignin purity of the lignin sulfonate is 40% or more and 95% or less.

[0031] Thereby, it is possible to enhance the certainty of forming the base material layer 11 containing lignin sulfonate.

[0032] The tensile elongation at break of the base material layer 11 may be, for example, 130% or more. The tensile elongation at break can be determined in accordance with JIS K 7161-1:2014 (ISO 527-1) "Plastics - Methods for determining tensile properties - Part 1: General principles" and JIS K 7127:1999 (ISO 527-3) "Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets". When the object to be measured does not have a yield point, the tensile fracture strain is measured, and when it has a yield point, the nominal strain at tensile fracture is measured, and the tensile elongation at break can be determined using these measured values.

[0033] The tensile strength at 100% elongation of the base material layer 11 may be, for example, 4 N / cm or less. The tensile strength at 100% elongation is the value obtained by dividing the magnitude of the force measured when the strain defined in JIS K 7161-1:2014 (ISO 527-1) "Plastics - Methods for determining tensile properties - Part 1: General principles" reaches the specified value (100%) by the width of the test piece. The tensile strength at 100% elongation (T) (N / cm) can be determined by the following formula.

[0034] T = F / W In the above formula, F is the magnitude of the measured force (N), and W is the width of the test piece (cm).

[0035] [Adhesive layer] The adhesive layer 12 is formed of a synthetic resin, similarly to the base material layer 11. The synthetic resin for forming the adhesive layer 12 may be, for example, a polyurethane resin. The thickness of the adhesive layer 12 may be, for example, 5 μm or more and 25 μm or less.

[0036] [Protective layer] The protective layer 13 is formed of a synthetic resin. The protective layer 13 is formed of, for example, a base material sheet and a release layer. The release layer is laminated on the base material sheet. When the protective layer 13 includes the base material sheet and the release layer, the release layer is in contact with the base material layer 11 of the sheet body 10B. The base material sheet may be formed of, for example, a polypropylene (PP) resin, a polyethylene terephthalate (PET) resin, or the like. The base material sheet may be any one of a uniaxially stretched sheet, a biaxially stretched sheet, and an unstretched sheet. The release layer may be formed of, for example, a silicone resin.

[0037] The protective layer 13 may be composed only of the above-described base material sheet. In this case, a process for facilitating peeling of the base material layer 11 from the base material sheet may be applied to the contact surface of the base material sheet that contacts the base material layer 11. The process for the contact surface of the base material sheet may be, for example, embossing. The thickness of the protective layer 13 may be, for example, 30 μm or more and 400 μm or less.

[0038] [Release layer] The release layer 14 is configured such that the release strength between the release layer 14 and the adhesive layer 12 is smaller than the release strength between the protective layer 13 and the base material layer 11. The release layer 14 is formed of a synthetic resin. The release layer 14 is formed of, for example, a base material sheet and a release layer. The release layer is laminated on the base material sheet. When the release layer 14 includes the base material sheet and the release layer, the release layer is in contact with the adhesive layer 12 of the sheet body 10B. The base material sheet may be formed of, for example, a polyethylene terephthalate (PET) resin, or the like. The base material sheet may be any one of a uniaxially stretched sheet, a biaxially stretched sheet, and an unstretched sheet. The release layer may be formed of, for example, a silicone resin.

[0039] The release layer 14 may be composed only of the above-described base material sheet. In this case, a process for facilitating peeling of the adhesive layer 12 from the base material sheet may be applied to the contact surface of the base material sheet that contacts the adhesive layer 12. The process for the contact surface of the base material sheet may be, for example, embossing. The thickness of the release layer 14 may be, for example, 12 μm or more and 350 μm or less.

[0040] [Examples] Examples and comparative examples will be described with reference to FIGS. 3 and 4. In each of the examples and the comparative examples, the following ultraviolet absorbers were used.

[0041] Example 1: Sodium lignosulfonate, Manufactured by Nippon Paper Industries Co., Ltd., Sun Extract (registered trademark) P252 Mass average molecular weight: greater than 1000 and 5000 or less Lignin purity: 50% Example 2: Sodium lignosulfonate, Manufactured by Nippon Paper Industries Co., Ltd., Pearllex (registered trademark) NP Mass average molecular weight: greater than 10000 and 20000 or less Lignin purity: 86% Example 3: Sodium lignosulfonate, Manufactured by Nippon Paper Industries Co., Ltd., Vanilex (registered trademark) N Mass average molecular weight: greater than 5000 and 10000 or less Lignin purity: 91% Example 4: Hardwood kraft lignin Example 5: Softwood kraft lignin Comparative Example 2: Magnesium lignosulfonate, Manufactured by Nippon Paper Industries Co., Ltd., Sun Extract (registered trademark) P321 Mass average molecular weight: greater than 1000 and 5000 or less Lignin purity: 60% Comparative Example 3: Sunscreen agent Sun Cut Perfect UV Essence, Kose Corporation Comparative Example 4: Hexyl benzoate Comparative Example 5: Titanium oxide Comparative Example 6: Titanium oxide

[0042] The hardwood lignin used in Example 4 was prepared by the following method. Japanese beech peeled chips were prepared as the pulp raw material. A cooking liquor with a sulfidity of 25% or more and 30% or less and an effective alkali of 40 g / l was prepared. The peeled chips were cooked by putting 500 g of the peeled chips and 2.5 l of the cooking liquor into a rotary autoclave. At this time, the cooking temperature was set at 170°C and the cooking time was set at 2 hours. Thereby, kraft pulp was obtained.

[0043] Concentrated sulfuric acid was added to the waste liquor obtained when the peeled chips were cooked to set the pH of the waste liquor to 2. Then, the waste liquor was centrifuged to collect the precipitate formed in the waste liquor. After washing the precipitate with distilled water, it was dried at 60°C for one day and night, and then the dried precipitate was dissolved in 20% water-containing acetone to obtain a precipitate solution. While stirring 4 times the amount of 20% hydrochloric acid of 20% water-containing acetone, the precipitate solution was dropped into 20% hydrochloric acid to form a precipitate. The 20% hydrochloric acid containing the precipitate was centrifuged to recover the precipitate. Subsequently, the precipitate was washed twice with distilled water at 40°C and then dried at 60°C, thereby preparing hardwood kraft lignin which is kraft lignin with hardwood as the raw material.

[0044] Also, when preparing the softwood lignin used in Example 5, in the method of preparing hardwood lignin, the beech chips were changed to cedar chips. Otherwise, softwood kraft lignin which is kraft lignin with softwood as the raw material was prepared by the same method as the method of preparing hardwood lignin.

[0045] [Example 1] A biaxially oriented polypropylene (OPP) film (manufactured by Futamura Chemical Co., Ltd., FOR-MP), where one of the pair of opposing surfaces in the thickness direction is a matte surface, was prepared as a protective layer. Then, a first coating solution was obtained by adding a lignin sulfonate to an aqueous polyurethane (manufactured by Mitsui Chemicals, Inc., Takelac WS-6021) (Takelac is a registered trademark) containing an ether-based polyol. When setting the sum of the solid content of the aqueous polyurethane and the lignin sulfonate in the first coating solution to 100% by mass, the lignin sulfonate was added to the aqueous polyurethane so that the lignin sulfonate was 5% by mass. Next, after coating the first coating solution on the matte surface of the OPP film, the first coating solution was dried to obtain a first coating film having a thickness of 15 μm. Thereafter, the first coating film was aged at room temperature for 48 hours to obtain a base material layer having a thickness of 15 μm.

[0046] A release film (manufactured by Toray Film Processing Co., Ltd., Serapil WZ) (Serapil is a registered trademark) composed of a PET film and a release layer was prepared as a release layer. Also, a urethane-based pressure-sensitive adhesive (manufactured by Toyochem Co., Ltd., SP-205) as the main agent, a curing agent (manufactured by Toyochem Co., Ltd., T-501B), and a diluting solvent (manufactured by Toyo Ink Co., Ltd., NC401 Solvent C) were prepared. Then, the viscosity of the main agent was adjusted by adding twice the amount of the diluting solvent to the main agent. Next, the curing agent was added to the main agent, and subsequently, the mixture of the main agent and the curing agent was stirred to obtain a second coating solution for forming an adhesive layer. After coating the second coating solution on the release layer of the release film, the second coating solution was dried to obtain an adhesive layer having a thickness of 15 μm.

[0047] Next, by laminating the adhesive layer to the base material layer, a laminate in which the adhesive layer and the base material layer were sandwiched between the protective layer and the release layer was obtained. Subsequently, the laminate was aged at 50°C for 72 hours to obtain the skin patch sheet of Example 1.

[0048] [Example 2] In Example 1, sodium lignosulfonate was changed from Sun Extract P252 to Pearllex NP, and the mixing ratio of sodium lignosulfonate was changed from 5% by mass to 20% by mass. Otherwise, a skin patch sheet of Example 2 was obtained by the same method as in Example 1.

[0049] [Example 3] In Example 1, sodium lignosulfonate was changed from Sun Extract P252 to Vanilex N, and the mixing ratio of sodium lignosulfonate was changed from 5% by mass to 20% by mass. Otherwise, a skin patch sheet of Example 3 was obtained by the same method as in Example 1.

[0050] [Example 4] In Example 1, a skin patch sheet of Example 4 was obtained by the same method as in Example 1, except that sodium lignosulfonate was changed from Sun Extract P252 to kraft lignin extracted from beech chips.

[0051] [Example 5] In Example 1, a skin patch sheet of Example 5 was obtained by the same method as in Example 1, except that sodium lignosulfonate was changed from Sun Extract P252 to kraft lignin extracted from cedar chips.

[0052] [Comparative Example 1] In Example 1, when preparing the first coating solution, sodium lignosulfonate was not added to the aqueous polyurethane, and a first coating film composed only of the aqueous polyurethane was obtained. Otherwise, a skin patch sheet of Comparative Example 1 was obtained by the same method as in Example 1.

[0053] [Comparative Example 2] In Example 1, sodium lignosulfonate was changed from Sun Extract P252 to Sun Extract P321.

[0054] [Comparative Example 3] In Example 1, sodium lignosulfonate was changed to a sunscreen agent.

[0055] [Comparative Example 4] In Example 1, sodium lignosulfonate was changed to hexyl benzoate.

[0056] [Comparative Example 5] A skin patch of Comparative Example 5 was obtained in the same manner as in Example 1, except that sodium lignosulfonate was changed to titanium oxide in Example 1.

[0057] [Comparative Example 6] A skin patch of Comparative Example 6 was obtained in the same manner as in Example 1, except that sodium lignosulfonate was changed to titanium oxide and the blending ratio of titanium oxide was changed from 5% by mass to 20% by mass in Example 1.

[0058] [Evaluation Method] [Transmittance] A 50 mm square test piece was cut out from the skin patch of each example and each comparative example. After peeling off the release layer from the test piece, the adhesive layer was attached to the measurement backing paper. Then, the protective layer was peeled off from the test piece attached to the measurement backing paper. And for the test pieces of each example and each comparative example, the transmittance in the wavelength range of 220 nm or more and 800 nm or less was measured using a spectrophotometer (Shimadzu Corporation, UV-3600).

[0059] [Breaking Strength] Test pieces having the shape of "test piece type 5" defined in JIS K 7127:1999 "Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets" were cut out from the skin patches of each example and each comparative example. Then, the breaking strength of the sheet body was measured by a tensile test in accordance with JIS K 7127:1999 "Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets". When measuring the breaking strength, the release layer and the protective layer were removed from the test piece. Also, an autograph testing machine ((Shimadzu Corporation, Autograph AGS-X load cell 1 kN) (Autograph is a registered trademark)) was used as the tensile testing machine, and the test speed was set to 300 mm / min. Also, for the skin patches of each example and each comparative example, three test pieces were prepared, and the average value of the breaking strengths obtained for the three test pieces was set as the breaking strength of each sheet body.

[0060] [Peeling strength] The peeling strength between the base material layer and the protective layer was measured by a tensile test in accordance with JIS K 7127:1999 "Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets". At this time, an autograph testing machine ((Shimadzu Corporation, Autograph AGS-X load cell 1 kN) (Autograph is a registered trademark)) was used as the tensile testing machine, and the test speed was set to 300 mm / min. Also, for the skin patches of each example and each comparative example, three test pieces were prepared, and the average value of the peeling strengths obtained for the three test pieces was set as the peeling strength of each skin patch.

[0061] [White floating] Rectangular test pieces having a width of 30 mm and a length of 40 mm were cut out from the skin patches of each example and each comparative example. Then, after removing the release layer from the adhesive layer of the test piece, the adhesive layer was attached to the outer side of the subject's upper arm. Subsequently, the protective layer was removed from the base material layer of the test piece.

[0062] An observation point was set such that the distance between the subject's eye and the test piece attached to the upper arm was 30 cm. Then, the appearance of the upper arm when visually observing the sheet body from the observation point was evaluated at the following two levels.

[0063] ○: The color exhibited by the sheet body does not show a white floating against the color exhibited by the upper arm, so the sheet body is not conspicuous. ×: The color exhibited by the sheet body shows a white floating against the color exhibited by the upper arm, so it can be seen at a glance that the sheet body is attached to the upper arm.

[0064] [Evaluation Results] Regarding the skin patch sheets of each example and each comparative example, the results of evaluating the transmittance, breaking strength, peel strength, and white floating were as shown in Figure 3.

[0065] First, when forming the base material layer containing each of the above-mentioned ultraviolet absorbers, it was recognized that in Examples 1 to 5 and Comparative Examples 1, 5, and 6, the base material layer could be formed, while in Comparative Examples 2 to 4, the formation of the base material layer was impossible. Specifically, it was recognized that magnesium lignosulfonate used in Comparative Example 2 was not uniformly dispersed in the first coating liquid for forming the base material layer. Also, in Comparative Example 3, since the sunscreen agent has water repellency, the first coating liquid containing the sunscreen agent was repelled by the protective layer. As a result, it was recognized that the first coating liquid could not form a film, and thus the formation of the first coating film was impossible. Further, in Comparative Example 4, similar to Comparative Example 3, since hexyl benzoate, which is an organic compound, has water repellency, the first coating liquid containing hexyl benzoate was repelled by the protective layer. As a result, it was recognized that the first coating liquid could not form a film, and thus the formation of the first coating film was impossible.

[0066] From the comparison between Examples 1 to 5 and Comparative Example 2, it can be said that since sodium lignosulfonate used in Examples 1 to 3 has higher solubility in water than magnesium lignosulfonate used in Comparative Example 2, it dissolves in water which is the dispersion medium of the aqueous polyurethane, and thus film formation of the base material layer 11 is possible. On the other hand, it can be said that magnesium lignosulfonate used in Comparative Example 2 has low solubility in water, and as a result, film formation of the base material layer 11 was impossible. Also, since the kraft lignin of Examples 4 and 5 is soluble in an alkaline aqueous solution, it can be said that film formation of the base material layer 11 was possible in Examples 4 and 5.

[0067] As shown in FIG. 3, it was confirmed that the transmittance in the wavelength range of 280 nm or more and 400 nm or less was 25% or more and 83% or less in Example 1, 0.2% or more and 46% or less in Example 2, and 0.05% or more and 12% or less in Example 3. Also, it was confirmed that the transmittance in the wavelength range of 280 nm or more and 400 nm or less was 12% or more and 61% or less in Example 4, and 44% or more and 73% or less in Example 5. Also, it was confirmed that the transmittance in the wavelength range of 280 nm or more and 400 nm or less was 84% or more and 88% or less in Comparative Example 1, 55% or more and 69% or less in Comparative Example 5, and 20% or more and 38% or less in Comparative Example 6.

[0068] The breaking strength of the sheet body was 13 N / mm in Example 1 2 and 11 N / m in Example 2 2 and 8 N / mm in Example 3 2 and 15 N / mm in Example 4 2 and 21 N / mm in Example 5 2 It was confirmed that. The breaking strength of the sheet body was 18 N / mm in Comparative Example 1 2 and 13 N / mm in Comparative Example 5 2 and 9 N / mm in Comparative Example 6 2 It was confirmed that.

[0069] The peel strength between the base material layer and the protective layer was found to be 0.16 N / 25 mm in Example 1 and 0.09 N / 25 mm in Example 2. The peel strength between the base material layer and the protective layer was found to be 0.12 N / 25 mm in Example 3, 0.14 N / 25 mm in Example 4, and 0.13 N / 25 mm in Example 5. The peel strength between the base material layer and the protective layer was found to be 0.16 N / 25 mm in Comparative Example 1 and 0.14 N / 25 mm in Comparative Examples 5 and 6.

[0070] The evaluation results of whitening were found to be "○" in Examples 1 to 5 and Comparative Example 1, and "×" in Comparative Examples 5 and 6. Thus, in Examples 1 to 5, it was confirmed that the transmittance in the entire range of 280 nm or more and 400 nm or less was 83% or less, and both the evaluation results of whitening were "○". On the other hand, in Comparative Examples 1, 5, and 6, it was confirmed that at least one of the following was satisfied: the transmittance exceeded 83% in at least a part of the wavelength range of 280 nm or more and 400 nm or less, and the evaluation result of whitening was "×". That is, in Comparative Examples 1, 5, and 6, only the transmittance exceeding 83% in at least a part of the wavelength range of 280 nm or more and 400 nm or less may be satisfied, only the evaluation result of whitening being "×" may be satisfied, or both of these may be satisfied.

[0071] As described above, in Comparative Examples 2 to 4, it was impossible to form the base material layer, so for Comparative Examples 2 to 4, the transmittance, breaking strength, peel strength, and evaluation of whitening were not performed. As a result, it was confirmed that the evaluation results of Examples 1 to 5 were "○" and the evaluation results of Comparative Examples 1 to 6 were "×".

[0072] Figure 4 is a transmittance curve of the skin patch sheets of each example and each comparative example. As shown in Fig. 4, according to the skin patches of Examples 1 to 5, it was confirmed that the transmittance was reduced in the entire range of 280 nm or more and 400 nm or less compared to the skin patch of Comparative Example 1 that does not contain an ultraviolet absorber. Further, according to the skin patches of Examples 1 to 5, it was confirmed that they have the same transmittance as or lower transmittance than the skin patch of Comparative Example 5 containing 5% by mass of titanium oxide in the entire range of 280 nm or more and 400 nm or less. In particular, in the skin patches of Examples 2 to 4, it was confirmed that the transmittance was reduced in the entire range of 280 nm or more and 400 nm or less compared to the skin patch of Comparative Example 5.

[0073] As described above, according to one embodiment of the skin patch, the following effects can be obtained. (1) Since the base material layer 11 and the adhesive layer 12 are in a solid state, even when the user touches the sheet body 10B attached to the skin, compared with a liquid cosmetic, the position of the sheet body 10B with respect to the skin is less likely to shift or the sheet body 10B is less likely to be removed from the skin. Thereby, the ultraviolet absorption ability of the lignin sulfonate or kraft lignin contained in the base material layer 11 is likely to be maintained at the position where the user attached the sheet body 10B. In addition, since the color exhibited by lignin sulfonic acid or kraft lignin does not greatly deviate from the color exhibited by the skin, it is possible to suppress the sheet body 10B from appearing to float from the skin.

[0074] (2) When Conditions 5 and 6 are satisfied, it is possible to enhance the certainty of obtaining the ultraviolet absorption ability by the ultraviolet absorber contained in the base material layer 11. (3) When Conditions 7 and 8 are satisfied, it is possible to enhance the certainty of forming the base material layer 11 containing lignin sulfonate.

[0075] (4) When Condition 3 is satisfied, the sheet body 10B can have a sufficiently high breaking strength to withstand stretching for following the skin. (5) When Condition 4 is satisfied, it is easy to peel the protective layer 13 from the base material layer 11.

[0076] (6) By the aqueous polymer compound being a polyurethane resin, it is possible to obtain the base material layer 11 having high followability with respect to the skin.

[0077] Note that the above-described embodiments can be implemented with the following modifications. [Cut] · The protective layer 13 may not have the cut 13B. Even in this case, it is possible to obtain the effect according to (1) described above.

[0078] [Base material layer] · The base material layer 11 may contain at least one of lignin sulfonate and kraft lignin. That is, the base material layer 11 may contain only lignin sulfonate, may contain only kraft lignin, or may contain both lignin sulfonate and kraft lignin. Even in any of these cases, it is possible to obtain the effect according to (1) described above.

Explanation of reference numerals

[0079] 10…Skin patch sheet 10B…Sheet body 11…Base material layer 12…Adhesive layer 13…Protective layer 14…Release layer

Claims

1. A base material layer containing an aqueous polymer compound and at least one of lignin sulfonate and kraft lignin, and an adhesive layer laminated on the base material layer and attached to the skin. In the sheet body including the base material layer and the adhesive layer, the transmittance in the entire range of 280 nm or more and 400 nm or less is 83% or less. A skin patch.

2. The lignin sulfonate or the kraft lignin is an ultraviolet absorber, the thickness of the base material layer is 5 μm or more and 30 μm or less, and the base material layer contains 2% by mass or more and 20% by mass or less of the ultraviolet absorber. The skin patch according to Claim 1.

3. Containing the lignin sulfonate, the lignin sulfonate is a sodium salt, and the lignin purity of the lignin sulfonate is 40% or more and 95% or less. The skin patch according to Claim 1 or 2.

4. The breaking strength of the sheet body is 5 N / mm ２ or more The skin patch according to Claim 1 or 2.

5. Further comprising a protective layer in contact with the base material layer on the side opposite to the adhesive layer with respect to the base material layer, and the peel strength between the base material layer and the protective layer is 0.2 N / 25 mm or less. The skin patch according to Claim 1 or 2.

6. The aqueous polymer compound is a polyurethane resin. The skin patch according to Claim 1 or 2.

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