Skin treatment device and electroconductive sheet

Abstract

[Problem] To provide a skin treatment device that is capable of applying, in response to a request of a user, skin treatment to a skin surface in a variety of areas. [Solution] According to one embodiment of the present invention, a skin treatment device is provided. This skin treatment device comprises: an electroconductive sheet at least part of which is stretchable in a given direction, or an electroconductive sheet at least part of which is flexible so as to be capable of following a skin surface; and a device body which is attached to the electroconductive sheet to supply electric current to the skin surface of a user. The electroconductive sheet has a sheet base material, an electroconduction pattern, and a bioadhesive layer. The electroconduction pattern is provided to one surface side of the sheet base material, and comprises a wiring part and an electrode part that is connected to one end side of the wiring part. The bioadhesive layer is provided to a side of the electroconduction pattern opposite to the sheet base material, and is configured so as to be adhered to the skin surface of the user.

Description

Skin treatment device and conductive sheet

[0001] The present invention relates to a skin treatment device and a conductive sheet.

[0002] Devices aimed at enhancing the cosmetic effects on the face have been developed in the past (see Patent Document 1). Patent Document 1 discloses a cosmetic mask that is worn on the user's face and provides treatment through electrical stimulation. This cosmetic mask includes a mask body that covers substantially the entire face of the user, and a stimulator attached to the mask body that applies treatment waves to continuously apply electrical stimulation of a predetermined current intensity to areas corresponding to the user's cheeks.

[0003] Patent Publication No. 2022-116856

[0004] However, the above-mentioned cosmetic masks have the problem that the treatment area is limited to the cheeks of the user's face. In view of the above, the present invention provides a skin treatment device that can treat skin in various areas of the skin surface according to the user's needs.

[0005] According to one aspect of the present invention, a skin treatment device is provided. This skin treatment device includes a conductive sheet, at least a portion of which is stretchable in any direction, or a conductive sheet having flexibility such that at least a portion of the conductive sheet can conform to the skin surface, and a device main body attached to the conductive sheet and supplying current to the user's skin surface. The conductive sheet includes a sheet substrate, a conductive pattern, and a bioadhesive layer. The conductive pattern is provided on one side of the sheet substrate and includes a wiring portion and an electrode portion connected to one end of the wiring portion. The bioadhesive layer is provided on the side of the conductive pattern opposite the sheet substrate and is configured to be attached to the user's skin surface.

[0006] According to this aspect, it is possible to provide a skin treatment device that can perform skin treatment on the skin surface in various areas according to the user's request.

[0007] FIG. 1 is a plan view showing a disassembled state of a skin treatment device according to this embodiment. FIG. 2 is a plan view showing the device main body in FIG. 1 turned upside down. FIG. 3 is a plan view showing a disassembled conductive sheet of a first configuration example. FIG. 4 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 5 is a block diagram showing the configuration of the device main body. FIG. 6 is a plan view showing a disassembled conductive sheet having a biological adhesive layer of another configuration. FIG. 7 is a cross-sectional view of the conductive sheet of FIG. 6 corresponding to FIG. 4. FIG. 8 is a plan view showing a disassembled skin treatment device including a conductive sheet of a second configuration example. FIG. 9 is a plan view showing a conductive sheet of a third configuration example. FIG. 10 is a plan view showing a conductive sheet of a fourth configuration example. FIG. 11 is a bottom view showing a conductive sheet of a fifth configuration example. FIG. 12(a) is a plan view showing a conductive sheet 1 of a sixth configuration example, and FIG. 12(b) is a side view showing the conductive sheet 1 of the sixth configuration example. FIG. 13 is a cross-sectional view taken along line B-B in FIG. 12(a).

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. Various features shown in the following embodiments can be combined with each other.

[0009] Incidentally, the program for realizing the software appearing in this embodiment may be provided as a non-transitory computer-readable recording medium, or may be provided so as to be downloadable from an external server, or may be provided so that the program is started on an external computer and its functions are realized on a client terminal (so-called cloud computing).

[0010] In this embodiment, the term "unit" may also include, for example, a combination of hardware resources implemented by a circuit in the broad sense and software information processing that can be specifically realized by these hardware resources. In addition, this embodiment handles various types of information, which may be represented by, for example, physical values ​​of signal values ​​representing voltages and currents, high and low signal values ​​as a binary bit set consisting of 0 or 1, or quantum superposition (so-called quantum bits), and communication and calculations may be performed on a circuit in the broad sense.

[0011] Furthermore, a circuit in the broad sense is a circuit realized by at least an appropriate combination of a circuit, circuitry, a processor, a memory, etc. In other words, it includes an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)), etc.

[0012] First, the skin treatment device of the present invention will be described. FIG. 1 is a plan view showing a disassembled state of the skin treatment device according to this embodiment. FIG. 2 is a plan view showing the device main body in FIG. 1 turned upside down. FIG. 3 is a plan view showing the conductive sheet of a first configuration example disassembled. FIG. 4 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 5 is a block diagram showing the configuration of the device main body. In the following description, the front side of the pages in FIGS. 1 to 3 will also be referred to as the "front" or "top," the back side of the pages in FIGS. 1 to 3 will also be referred to as the "back" or "bottom," the upper side in FIG. 4 will also be referred to as the "front" or "top," and the lower side in FIG. 4 will also be referred to as the "back" or "bottom." The skin treatment device 100 shown in FIGS. 1 and 2 is used by adhering it to the skin surface of a user. This skin treatment device 100 includes a conductive sheet 1, at least a portion of which is stretchable in any direction, and a device main body 10 attached to the conductive sheet 1 and supplying current to the skin surface of the user.

[0013] First Configuration Example First, a first configuration example of the conductive sheet 1 will be described. As shown in FIGS. 3 and 4 , the conductive sheet 1 includes a sheet substrate 2, a conductive pattern 3, and a bioadhesive layer 4. Note that in FIGS. 1 and 2 , the conductive pattern 3 located on the back (lower) side of the sheet substrate 2 is indicated by diagonal lines. As shown in FIGS. 1 and 3 , the sheet substrate 2 includes a pair of generally rounded wide portions 21 and a narrow portion 22 connecting the wide portions 21, which are integrally formed. With this configuration, the sheet substrate 2 has a dumbbell shape in plan view. Furthermore, a protruding ear 23 is formed at the end of one of the wide portions 21 opposite the narrow portion 22. By gripping and manipulating the ear 23 with fingers or the like, the skin treatment device 100 can be smoothly peeled (removed) from the user's skin surface.

[0014] The sheet substrate 2 functions as a support layer that supports the conductive pattern 3 and the bioadhesive layer 4. This sheet substrate 2 is stretchable in any direction. Examples of the sheet substrate 2 include resin sheets such as polyethylene terephthalate sheets, polypropylene sheets, and polyethylene sheets; thermoplastic elastomer sheets such as urethane-based thermoplastic elastomer sheets; rubber sheets such as nitrile rubber sheets and urethane rubber sheets; paper substrates; woven fabrics; nonwoven fabrics; foam sheets; and laminated sheets obtained by laminating these. The thickness of the sheet substrate 2 is not particularly limited, but is preferably approximately 10 μm to 200 μm, and more preferably approximately 25 μm to 150 μm, from the viewpoint of ensuring high conformability of the conductive sheet 1 to the skin surface.

[0015] The durometer hardness A of the sheet substrate 2 is preferably about 10 or more and about 80 or less, and more preferably about 30 or more and about 70 or less. This can further improve the degree of deformation (bending, stretching, etc.) of the sheet substrate 2, and can also increase the friction durability and mechanical strength of the sheet substrate 2. The durometer hardness A of the sheet substrate 2 can be obtained by preparing a sheet-like test piece using the sheet substrate 2 and measuring its durometer hardness A at 25°C in accordance with JIS K 6253 (1997).

[0016] The tear strength of the sheet substrate 2 is preferably about 25 N / mm or more and 80 N / mm or less, and more preferably about 30 N / mm or more and 70 N / mm or less. This improves the durability of the sheet substrate 2 during repeated use. Furthermore, the sheet substrate 2 can be made less susceptible to breakage even when made thin. This allows for greater design freedom while balancing the various properties of the sheet substrate 2. The tear strength of the sheet substrate 2 can be obtained by preparing a crescent-shaped test piece using the sheet substrate 2 and measuring its tear strength at 25°C in accordance with JIS K6252 (2001).

[0017] The breaking elongation of the sheet substrate 2 is preferably about 100% or more and 2000% or less, more preferably about 200% or more and 1900% or less, and even more preferably about 300% or more and 1800% or less. This improves the high stretchability and durability of the sheet substrate 2 while balancing the various properties of the sheet substrate 2. The breaking elongation of the sheet substrate 2 can be calculated in accordance with JIS K 6251 (2004) by preparing a dumbbell-shaped No. 3 test piece using the sheet substrate 2, measuring its breaking elongation at 25°C, and then calculating [gauge line travel distance (mm)] ÷ [initial gauge line distance (20 mm)] × 100.

[0018] The tensile strength of the sheet substrate 2 is preferably about 5 MPa or more and 25 MPa or less, and more preferably about 10 MPa or more and 20 MPa or less. This makes it possible to improve the mechanical strength of the sheet substrate 2 while balancing the various properties of the sheet substrate 2. It is also possible to realize a sheet substrate 2 with excellent durability that can withstand repeated deformation. The tensile strength of the sheet substrate 2 is obtained by preparing a dumbbell-shaped No. 3 test piece using the sheet substrate 2 and measuring the tensile strength at 25°C in accordance with JIS K 6251 (2004).

[0019] The sheet substrate 2 preferably has high gas permeability (high oxygen permeability, high water vapor permeability). This makes it less likely that the skin surface will be damaged when treated by the skin treatment device 100. Specifically, the oxygen permeability of the sheet substrate 2 is, but is not particularly limited to, 1×10 ３ cm ３ / m ２ ・24h・atm or more is preferable, and 2×10 ３ cm ３ / m ２ The water vapor permeability of the sheet substrate 2 is preferably about 5 g / m or more, but is not particularly limited thereto. ２ ・24h・atm or more is preferable, and 10g / m ２ It is more preferable that the temperature is about 24h·atm or higher.

[0020] Two through holes 221 and two openings 222 are formed in the sheet substrate 2 (narrow width portion 22). Pins 101 of the device body 10 shown in FIG. 2 are inserted into the two through holes 221, respectively. By inserting the pins 101 into the through holes 221, the device body 10 can be positioned relative to the conductive sheet 1. That is, the skin treatment device 100 has a positioning portion for the device body 10 relative to the conductive sheet 1, which is composed of the pins 101 and the through holes 221. A portion of the conductive pattern 3 is exposed in each opening 222. As shown in FIG. 2, the device body 10 has a pair of terminal portions 11. When the device body 10 is positioned relative to the conductive sheet 1, the terminal portions 11 are inserted into the corresponding openings 222 and come into contact with the conductive pattern 3. This electrically connects the device body 10 and the conductive pattern 3.

[0021] The conductive pattern 3 is provided on the underside (one side) of the sheet substrate 2. The conductive pattern 3 may be disposed in direct contact with the sheet substrate 2, or may be disposed via an intermediate layer of any purpose. Functions of the intermediate layer include, for example, enhancing adhesion between the conductive pattern 3 and the sheet substrate 2, reinforcing the conductive pattern 3, and functions other than current conduction (e.g., a heating function or a magnetic force application function, as described below). As shown in FIG. 3 , the conductive patterns 3 are provided in pairs on the left and right, and the two conductive patterns 3 have substantially the same shape. Each conductive pattern 3 includes three wiring portions 31 and an electrode portion 32 connected to one end of each wiring portion 31. By dividing and arranging the electrode portions 32 in this manner, it becomes easier to supply current more uniformly to the skin surface.

[0022] Furthermore, the three wiring portions 31 join at the other end to form a joining portion 33. A connecting portion 34 protruding further toward the other end is integrally formed from the joining portion 33. As described above, the sheet substrate 2 has openings 222 that expose these connecting portions 34. When the device main body 10 is attached to the conductive sheet 1, the terminal portions 11 are inserted into the corresponding openings 222 and come into contact with the connecting portions 34. That is, the wiring portion 31 has, at its other end, a connecting portion 34 that is connected to one of the terminal portions 11. Such a conductive pattern 3 can also stretch in any direction.

[0023] The conductive pattern 3 can be made of, for example, a composite material (elastic conductive material) containing a conductive filler and an elastomer. Examples of the conductive filler include carbon materials such as carbon nanotubes and carbon nanohorns, and metal materials such as gold, silver, copper, and nickel. Examples of the elastomer include thermoplastic elastomers such as polyamide-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and urethane-based thermoplastic elastomers, and rubber materials such as ethylene propylene rubber, neoprene rubber, natural rubber, and silicone rubber. If such a composite material is used, the conductive pattern 3 can be produced relatively easily using a printing method.

[0024] The thickness of the conductive pattern 3 is not particularly limited, but is preferably approximately 1 μm to 50 μm, and more preferably approximately 5 μm to 25 μm, from the viewpoint of ensuring high conformability of the conductive sheet 1 to the skin surface and mechanical strength of the conductive pattern 3. When the resistance (at 25°C) of the entire combination of the conductive pattern 3 and the bioadhesive layer 4, or of the conductive pattern 3 alone, at unstretched (natural state) is R1 [Ω], and the resistance (at 25°C) of the entire combination of the conductive pattern 3 and the bioadhesive layer 4, or of the conductive pattern 3 alone, at 50% stretch is R2 (Ω), the relationship 1<R2 / R1≦20 is preferably satisfied, the relationship R2 / R1≦18 is more preferably satisfied, and the relationship R2 / R1≦16 is even more preferably satisfied. This level of resistance fluctuation allows for stable supply of current to the skin surface. When R1 is measured as the resistance between the lower surface (skin side) of the bioadhesive layer 4, or, when the bioadhesive layer 3 is omitted, the lower surface (skin side) of the conductive pattern 3 and the upper surface (power supply connection) of the connection part 34, it is preferably about 1000 Ω or less, more preferably about 600 Ω or less, even more preferably about 500 Ω or less, particularly preferably about 400 Ω or less, and most preferably about 300 Ω or less. R2 is preferably about 5000 Ω or less, more preferably about 2000 Ω or less, and even more preferably about 1500 Ω or less.

[0025] In this specification, the stretchability of the conductive pattern 3 is expressed as the elongation rate when the conductive pattern 3 is stretched in a certain direction. The certain direction can be, for example, the extension direction of the wiring portion 31. When the conductive pattern 3 is stretched in this extension direction, the elongation rate is preferably about 10% or more, more preferably about 20% or more, and even more preferably about 50% or more, and means a state in which no breaks occur in the conductive pattern 3 when stretched at that elongation rate. A conductive pattern 3 that satisfies these conditions can be determined to have stretchability. Furthermore, as shown in FIGS. 1 and 2 , portions of the wiring portion 31 and the electrode portion 32 are arranged along the outer edge of the sheet substrate 2. This allows for more uniform current supply to the area of ​​the skin surface to which the conductive sheet 1 is attached.

[0026] The bioadhesive layer 4 is provided on the side of the conductive pattern 3 opposite the sheet substrate 2. This bioadhesive layer 4 is configured to be attached to the user's skin surface. That is, the bioadhesive layer 4 functions to hold the entire skin treatment device 100 on the user's skin surface. The adhesive strength of the bioadhesive layer 4 varies slightly depending on the shape and size of the conductive pattern 3, but is preferably approximately 0.5 N / 20 mm to 10 N / 20 mm, and more preferably approximately 1 N / 20 mm to 6 N / 20 mm. If the bioadhesive layer 4 has an adhesive strength within this range, the conductive pattern 3 can be more securely held on the user's skin surface. The adhesive strength of the bioadhesive layer 4 refers to the adhesive strength at a 90° peel angle according to the adhesive tape test method of JIS Z 0237:2009.

[0027] As shown in Figure 3, a pair of bioadhesive layers 4 are also provided on the left and right sides, and the two bioadhesive layers 4 have approximately the same shape. Each bioadhesive layer 4 is large enough to encompass the conductive pattern 3 in a plan view. By covering the entire conductive pattern 3 with the bioadhesive layer 4 in this way, it becomes easier to supply current more uniformly to the skin surface. The bioadhesive layer 4 can be obtained by supplying the bioadhesive layer-forming material before gelation onto a release sheet to form a coating film and then crosslinking it. Alternatively, the bioadhesive layer-forming material before gelation may be supplied so as to cover the conductive pattern 3 and then crosslinked. Examples of crosslinking (polymerization) methods include heating, irradiating with light, or irradiating with radiation the bioadhesive layer-forming material.

[0028] Such a bioadhesive layer 4 can also stretch in any direction. The bioadhesive layer 4 is preferably a gel that has adhesive strength to the skin surface, particularly a highly hydrated adhesive gel. That is, the bioadhesive layer 4 is preferably in a gel state. The water content of the highly hydrated adhesive gel is not particularly limited, but is preferably approximately 10% by mass to 60% by mass, and more preferably approximately 15% by mass to 50% by weight. A moderate water content of the bioadhesive layer 4 suppresses swelling of the bioadhesive layer 4 when used in combination with a topical skin preparation, thereby preventing or suppressing a decrease in the adhesive strength of the conductive pattern 3. The highly hydrated adhesive gel is preferably a hydrogel containing, in addition to water, a polymer matrix and a plasticizer, and optionally, an electrolyte and a water-soluble polymer. The highly hydrated adhesive gel may also contain an active ingredient contained in a topical skin preparation, as described below. In this case, a plurality of fine needle-shaped protrusions (height: approximately 50 μm to 150 μm) may be formed on the skin-facing side of the bioadhesive layer 4. As a result, when the bioadhesive layer 4 is attached to the skin surface, the multiple projections penetrate the skin surface, thereby promoting the penetration of the active ingredient into the skin tissue (dermal tissue).

[0029] (Polymer Matrix) The polymer matrix is ​​not particularly limited as long as it is composed of a polymer compound that forms a network structure and can form a gel by containing at least water. In the present invention, a polymer compound that can be attached to the skin surface is preferably used. As such a polymer compound, a copolymer of a monofunctional monomer having one ethylenically unsaturated group and a crosslinkable monomer is particularly preferred. Examples of the monofunctional monomer include (meth)acrylamide-based monomers, (meth)acrylic acid ester-based monomers, and monomers such as (meth)acrylic acid or its salts. These monofunctional monomers may be used alone or in combination of two or more types.

[0030] Specific examples of the (meth)acrylamide-based monomer include N,N-dialkyl(meth)acrylamides such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, and N,N-diethyl(meth)acrylamide; N-alkyl(meth)acrylamides such as N-isopropyl(meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, and N-propyl(meth)acrylamide; N-hydroxyalkyl(meth)acrylamides such as N-hydroxyethyl(meth)acrylamide and N-hydroxymethyl(meth)acrylamide; amino group-containing cationic monomers such as dimethylaminopropyl(meth)acrylamide; sulfonic acid group-containing anionic monomers or salts thereof such as tert-butylacrylamidosulfonic acid; and derivatives thereof.

[0031] Specific examples of (meth)acrylic acid ester monomers include (meth)acrylic acid alkyl esters having an alkyl group having 1 to 18 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, and tert-butyl (meth)acrylate; alkoxy group-containing (meth)acrylic acid esters, such as 2-methoxyethyl (meth)acrylate, ethoxyethoxyethyl (meth)acrylate, and methoxytriethylene glycol (meth)acrylate; (meth)acrylic acid hydroxyalkyl esters, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; glycerin mono(meth)acrylate; polyalkylene glycol mono(meth)acrylate, such as polyethylene glycol mono(meth)acrylate; and (meth)acrylic acid esters having an aromatic ring, such as benzyl (meth)acrylate.

[0032] Specific examples of (meth)acrylic acid or a salt thereof include acrylic acid, methacrylic acid, sodium acrylate, potassium acrylate, and potassium methacrylate. In the hydrogel, the total content of structural units derived from monofunctional monomers is preferably about 10% by mass or more and about 50% by mass or less, and more preferably about 15% by mass or more and about 45% by mass or less, relative to the total mass of the hydrogel. By setting the total content of structural units derived from monofunctional monomers in the hydrogel within the above range, the flexibility of the hydrogel can be further improved while maintaining sufficient shape retention of the hydrogel.

[0033] Examples of crosslinkable monomers include compounds having two or more polymerizable carbon-carbon double bonds in the molecule. Specific examples of such compounds include divinylbenzene, divinylbiphenyl, N,N'-methylenebis(meth)acrylamide, ethylene glycol di(meth)acrylate, glycerin tri(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polyglycerin di(meth)acrylate. These crosslinkable monomers may be used alone or in combination of two or more.

[0034] In the hydrogel, the content of the structural unit derived from the crosslinking monomer is not particularly limited, since it varies slightly depending on the types of monofunctional monomer and crosslinking monomer used, but is preferably about 0.01% by mass or more and 0.5% by mass or less, and more preferably about 0.01% by mass or more and 0.1% by mass or less, relative to the total mass of the hydrogel. By setting the content of the structural unit derived from the crosslinking monomer in the hydrogel within the above range, the crosslink density can be sufficiently increased, thereby maintaining the shape stability of the gel and preventing or suppressing the gel from becoming too hard.

[0035] (Plasticizer) A plasticizer is a component added to a hydrogel for purposes such as imparting water retention (moisture retention) and suppressing water evaporation to maintain the flexibility of the gel. Polyoxyalkylene alkyl ethers and / or sugars are preferably used as such plasticizers. These compounds are more hydrophobic than polyhydric alcohols, and therefore reduce the penetration of water into the hydrogel from the outside, thereby preventing or suppressing swelling of the gel. Specific examples of polyoxyalkylene alkyl ethers include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene isostearyl ether; and polyoxypropylene alkyl ethers such as polyoxypropylene lauryl ether, polyoxypropylene stearyl ether, and polyoxypropylene isostearyl ether.

[0036] Sugars are classified as monosaccharides, disaccharides, or polysaccharides, and one of these may be used alone or two or more may be used in combination. Examples of monosaccharides include xylose, arabinose, glucose, galactose, and mannose. Examples of disaccharides include sucrose, maltose, cellobiose, and lactose. Examples of polysaccharides include oligosaccharides such as maltotriose, xylan, starch, cellulose, chitin, and chitosan. Amino sugars of these sugars and their N-acetylated products may also be used.

[0037] The content of the plasticizer is preferably about 10% by mass to about 60% by mass, and more preferably about 20% by mass to about 50% by mass, relative to the total mass of the hydrogel. By setting the content of the plasticizer in the hydrogel within this range, bleeding of the plasticizer onto the gel surface can be prevented, and the gel can be stabilized over a long period of time, maintaining its adhesive strength. Furthermore, the ratio of the polymer matrix to the plasticizer is preferably about 0.25:1 to about 3:1, and more preferably about 0.45:1 to about 2.5:1, by mass.

[0038] (Electrolyte) The electrolyte is a component added to the hydrogel for purposes such as imparting conductivity. Examples of the electrolyte include inorganic salts, organic salts, polymer salts, and mixtures thereof. Specific examples of inorganic salts include alkali metal halides, alkaline earth metal halides, other metal halides, hypochlorites, chlorites, chlorates, perchlorates, sulfates, carbonates, nitrates, phosphates, ammonium salts, and complex salts. Specific examples of organic salts include metal salts of carboxylic acids such as acetic acid, benzoic acid, lactic acid, tartaric acid, phthalic acid, succinic acid, adipic acid, and citric acid, metal salts of sulfonic acids, metal salts of amino acids, and organic ammonium salts. Specific examples of polymer salts include salts of poly(meth)acrylic acid, salts of polyvinylsulfonic acid, salts of polytertiarybutylacrylamidosulfonic acid, salts of polyallylamine, and salts of polyethyleneimine.

[0039] The content of the electrolyte is preferably about 0.001% by mass to 10% by mass, and more preferably about 0.1% by mass to 5% by mass, relative to the total mass of the hydrogel. By setting the content of the electrolyte in the hydrogel within this range, an increase in the impedance (Z) of the hydrogel can be prevented, and sufficient conductivity can be imparted to the hydrogel. The electrolyte may be added for the purpose of adjusting the pH of the hydrogel, improving the moisturizing performance of the hydrogel, imparting antibacterial properties to the hydrogel, etc.

[0040] (Water-Soluble Polymer) The water-soluble polymer is a component added for purposes such as imparting adhesiveness to the hydrogel. Examples of water-soluble polymers include polyvinylpyrrolidone, vinylpyrrolidone copolymer, polyvinyl alcohol, polyacrylic acid, sodium polyacrylate, sodium carboxymethylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium alginate, and dextran. These water-soluble polymers may be used alone or in combination of two or more. Among these, polyacrylic acid and / or sodium polyacrylate are preferred as the water-soluble polymer because of their excellent effect of imparting adhesiveness to the hydrogel. The content of the water-soluble polymer is preferably about 0.1% by mass or more and about 5% by mass or less relative to the total mass of the hydrogel.

[0041] (Other Additives) Other ingredients such as preservatives, bactericides, anti-rust agents, antioxidants, stabilizers, fragrances, surfactants, colorants, anti-inflammatory agents, vitamins, whitening agents, etc. may be added to the hydrogel as needed, as long as they do not impair the effects of the present invention. These additives may be used alone or in combination of two or more. The content of these additives is preferably about 0.01% by mass or more and 10% by mass or less relative to the total mass of the hydrogel.

[0042] Such hydrogels can be prepared, for example, as follows. When the polymer matrix is ​​composed of a polymer of a monofunctional monomer and a crosslinkable monomer, they can be easily prepared by copolymerizing the monofunctional monomer and the crosslinkable monomer in a mixture liquid prepared by uniformly mixing and dissolving the monofunctional monomer, crosslinkable monomer, and plasticizer in water. If necessary, a water-soluble polymer, an electrolyte, and / or other additives can be added to the mixture liquid. Alternatively, the hydrogel can be prepared by impregnating a polymer matrix previously formed by polymerizing the monofunctional monomer and the crosslinkable monomer with water and a plasticizer, and, if necessary, a water-soluble polymer, an electrolyte, and / or other additives.

[0043] The polymerization of the monofunctional monomer and the crosslinkable monomer is preferably carried out in the presence of a polymerization initiator. Examples of the polymerization initiator that can be used include thermal polymerization initiators and photopolymerization initiators. Examples of the thermal polymerization initiator include compounds that cleave when heated to generate radicals. Examples of such thermal polymerization initiators include benzoyl peroxide, azobiscyanovaleric acid, azobisisobutyronitrile, azobisamidinopropane dihydrochloride, potassium persulfate, and ammonium persulfate. These thermal polymerization initiators may be used alone or in combination. If necessary, a redox initiator consisting of a reducing agent such as ferrous sulfate or pyrosulfite and a peroxide such as hydrogen peroxide, sodium thiosulfate, or peroxodisulfate may be used in combination with the thermal polymerization initiator.

[0044] As the photopolymerization initiator, a compound that is cleaved by ultraviolet or visible light to generate radicals can be used, for example, azo polymerization initiators such as 2,2'-azobis-N-(2-hydroxyethyl)propionamide and 2,2'-azobis(1-imino-1-pyrrolidino-2-methylpropane) dihydrochloride, α-hydroxyketone, α-aminoketone, benzyl methyl ketal, bisacylphosphine oxide, metallocene, etc. Specific examples of the photopolymerization initiator include 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-1-[(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, etc. These photopolymerization initiators may be used alone or in combination of two or more.

[0045] The content of the polymerization initiator is preferably approximately 0.01% by mass to 1% by mass, and more preferably approximately 0.05% by mass to 0.5% by mass, relative to the total mass of the hydrogel (total mass of the material for forming the bioadhesive layer). Setting the content of the polymerization initiator in the hydrogel within the above range ensures sufficient polymerization reaction and reduces the amount of monofunctional monomers and crosslinkable monomers remaining in the resulting hydrogel. It also prevents discoloration (yellowing) and odor caused by the polymerization initiator remaining in the resulting hydrogel. The thickness of the bioadhesive layer 4 is not particularly limited, but is preferably approximately 50 μm to 500 μm, and more preferably approximately 100 μm to 350 μm, from the viewpoint of ensuring high conformability of the conductive sheet 1 to the skin surface and the mechanical strength of the bioadhesive layer 4.

[0046] The bioadhesive layer 4 does not necessarily have to cover the entire conductive pattern 3, but can also cover only a portion of the conductive pattern 3. In the latter case, the conductive sheet 1 is attached such that the conductive pattern 3 directly adheres to the skin surface in areas where the bioadhesive layer 4 is not present, and the bioadhesive layer 4 directly adheres to the skin in areas where the bioadhesive layer 4 is present. In this case, the presence of the bioadhesive layer 4 reliably maintains the conductive sheet 1 adhered to the user's skin, while a stronger current provides muscle stimulation to the skin surface where the conductive pattern 3 directly adheres. Furthermore, the conductive sheet 1 may be at least partially stretchable in any direction. Therefore, the conductive sheet 1 may be configured to include stretchable and non-stretchable portions as a whole, such as in an embodiment where the sheet substrate 2 is stretchable but the conductive pattern 3 is not necessarily stretchable, or in an embodiment where the sheet substrate 2 and / or the conductive pattern 3 include stretchable and non-stretchable portions. Furthermore, the conductive sheet 1 may be configured to be non-stretchable, with at least a portion of it being flexible enough to conform to the skin surface. In this case, the range of materials to be used for the sheet substrate 2 and the conductive pattern 3 can be expanded.

[0047] The device main body 10 is attached to such a conductive sheet 1. In the first configuration example, the conductive sheet 1 is elongated, and the device main body 10 is attached to the central portion (narrow portion 22) in the longitudinal direction of the conductive sheet 1. As described above, a pair of pins 101 and a pair of terminal portions 11 protrude from the back surface of the device main body 10. The pair of pins 101 are each inserted into corresponding through holes 221 formed in the narrow portion 22 of the sheet base material 2. The pair of terminal portions 11 are each inserted into corresponding openings 222 formed in the narrow portion 22 of the sheet base material 2. In this way, the device main body 10 is connected (fixed) to the conductive sheet 1.

[0048] With this configuration, in this embodiment, the device main body 10 is detachably attached to the conductive sheet 1. The device main body 10 may also be fixed to the conductive sheet 1 in an undetachable manner. When the device main body 10 is configured to be detachably attached to the conductive sheet 1, it is preferable that the device main body 10 be attached to the conductive sheet 1 by magnetic force. For example, a permanent magnet can be disposed inside or on the back surface of the device main body 10, and the permanent magnet can be attracted to the conductive pattern 3 by magnetic force. This detachment mechanism has a simple configuration and also contributes to preventing the device main body 10 from becoming larger. Furthermore, when the device main body 10 is configured to be attracted to the conductive sheet 1 by magnetic force, permanent magnets with opposite polarities (south pole and north pole) can be disposed on both the device main body 10 and the conductive sheet 1, respectively, to prevent the device main body 10 from being attached in the reverse direction to the conductive sheet 1. The device main body 10 may also be configured to be attached to the longitudinal end of the conductive sheet 1. In this case, the wiring portion 31 extends to the end of the sheet substrate 2, and the connection portion 34 is connected to its tip. This configuration can also be employed in the conductive sheet 1 of other configurations and the conductive sheet 1 of the second configuration example, which will be described later.

[0049] Furthermore, it is desirable for the device main body 10 to be as small as possible, with a mass that does not interfere with its close contact with the skin surface. Therefore, the device main body 10 is made lighter and smaller by using a flexible substrate. In this case, the skin treatment device 100 preferably includes multiple conductive sheets 1 of different types, and the device main body 10 is preferably detachably attached to each conductive sheet 1. This allows the user to select and use the appropriate conductive sheet 1 depending on the area of ​​the skin to be treated, making it easier to more reliably perform skin treatment according to the user's needs. A second configuration example of the conductive sheet 1 will be described later.

[0050] As shown in FIG. 5 , two operation buttons 12 are provided on the surface of the device main body 10. These operation buttons 12 are capable of changing at least one of the amount of power supply or the supply pattern (mode). Changing the amount of power supply also includes turning the power supply (power supply) on and off. The device main body 10 also includes a power supply unit 13, a control unit 14, and an electrical circuit unit 15. The control unit 14 is electrically connected to the power supply unit 13, the electrical circuit unit 15, and the two operation buttons 12, and the electrical circuit unit 15 is electrically connected to two terminals 11. The power supply unit 13 is configured to supply power to the electrode unit 32. The power supply unit 13 can be, for example, a dry cell battery, a solar cell, a fuel cell, a lithium-ion secondary battery, an all-solid-state battery, a lithium polymer battery, or the like. The power supply unit 13 may also be a connector to which a power cable can be connected.

[0051] The control unit 14 incorporates a processing element and a memory element. The processing element is composed of, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), etc. The processing element realizes various functions related to the skin processing device 100 by reading out predetermined programs stored in the memory element. In other words, information processing by the software stored in the memory element is specifically realized by the processing element. Note that the processing element is not limited to a single element, and multiple processing elements may be provided for each function. A combination of these may also be used.

[0052] The memory element stores various pieces of information defined above. This can be implemented, for example, as a storage device such as a solid state drive (SSD) that stores various programs related to the skin processing device 100 executed by the processing element, or as a memory such as a random access memory (RAM) that stores temporarily required information (arguments, arrays, etc.) related to program calculations. The memory element also stores various programs, variables, etc. related to the skin processing device 100 executed by the processing element.

[0053] The electrical circuit unit 15 includes, for example, a drive circuit, an output waveform generating circuit, a transformer, a switching circuit, etc. The control unit 14 is configured to control the power supplied from the power supply unit 13 to the electrode unit 32 via the electrical circuit unit 15. Here, power control refers to setting at least one of the voltage value, current value, waveform, frequency, pulse width, current direction, and current duration. In this embodiment, the current supplied by the device main body 10 under the control of the control unit 14 is at least one of a current that promotes penetration of the active ingredient contained in the topical skin preparation, a current that stimulates muscles, a current that warms the skin surface, and a microcurrent. The type (mode) of current supplied by the device main body 10 can be changed by operating the operation button 12.

[0054] The current that promotes the penetration of the active ingredient contained in the topical skin preparation preferably uses currents with multiple pulse waveforms. This allows the active ingredient contained in the topical skin preparation to penetrate skin tissue more quickly. For example, the current with the first pulse waveform preferably has a frequency of about 1.5 kHz ± 10% and a voltage of about 20 V or less. In this case, it is more preferable to generate one pulse with reversed polarity for each of multiple (e.g., seven) pulses of the same polarity. Furthermore, the current with the second pulse waveform preferably has a frequency of about 1 Hz to 1 kHz and a voltage of about 20 V to 50 V.

[0055] The order of supplying these two types of current to the skin surface can be arbitrary, but preferably alternate.The combination of current is not limited to this, and it is preferable to combine stimulation according to the purpose, the penetration component, and the user's preference for sensation, to promote the penetration of the active ingredient contained in the skin preparation.For example, the current with the third pulse waveform can also be used.In this case, the current preferably has a frequency of 10Hz or more and 100Hz or less, and a voltage of 50V or more.By combining the current with the first pulse waveform and the current with the third pulse waveform, even when worn on the skin surface, it can be used in a mild stimulation mode.

[0056] Furthermore, the current having multiple types of pulse waveforms may include a current having a frequency of 1 kHz and currents having multiple frequencies, centered on a current having a frequency of about 10 Hz or more and 50 Hz or less (myogenic potential stimulation). The current that promotes the penetration of the active ingredient contained in the topical skin preparation is not limited to a combination of currents having multiple types of pulse waveforms, and may be a current having a single waveform for iontophoresis used alone or in combination with a current having at least one arbitrary pulse waveform.

[0057] The current that applies muscle stimulation EMS (Electrical Muscle Stimulation) preferably has a frequency of about 1 Hz or more and 1 kHz or less. This causes muscle contraction, allowing muscle movement and relieving tension. The current that heats the skin surface (high-frequency current) preferably has a frequency of about 10 kHz or more, more preferably about 10 kHz or more and 500 kHz or less. The frequency of microcurrent is preferably about 1200 Hz or less.

[0058] The following compounds can be mentioned as active ingredients contained in the external skin preparation used with the skin treatment device 100. Specific examples of active ingredients include tranexamic acid or a derivative thereof (such as cetyl tranexamate hydrochloride), niacinamide, pyridoxine hydrochloride or a derivative thereof, benzalkonium chloride, palmitoyl tripeptide-5, acetyl hexapeptide-8, dipeptide diaminobutyroylbenzylamide diacetate or a derivative thereof, allantoin, aldioxa, carnitine HCl, urea, etc.

[0059] Other specific examples of active ingredients include, for example, potassium 4-methoxysalicylate, disodium adenosine monophosphate, ascorbic acid or a derivative thereof (L-ascorbic acid 2-glucoside, sodium L-ascorbyl phosphate, disodium L-ascorbyl sulfate, trisodium ascorbyl palmitate phosphate, etc.), sodium dl-α-tocopheryl phosphate, zinc paraphenolsulfonate, salicylic acid and its sodium salt, sodium lactate, sodium L- or DL-pyrrolidonecarboxylate, sodium L-glutamate, sodium L-aspartate, glycyrrhizic acid or a salt thereof (dipotassium glycyrrhizinate, ammonium glycyrrhizinate, etc.), sodium guaiazulene sulfonate, sodium dilauroyl glutamate lysine, etc.

[0060] Other specific examples of active ingredients include kojic acid, arbutin, hydroquinone, 4-n-butylresorcinol, 5,5'-dipropyl-biphenyl-2,2'-diol, ellagic acid, ascorbic acid derivatives (3-O-ethyl ascorbic acid, 3-glyceryl ascorbic acid, bisglyceryl ascorbic acid, hexyl 3-glyceryl ascorbic acid, myristyl 3-glyceryl ascorbic acid, 3-laurylglyceryl ascorbic acid, etc.), D-pantothenyl alcohol, cholecalciferol, 3-o-cymen-5-ol (isopropylmethylphenol), glycine, proline, alanine, serine, acetylhydroxyproline, ε-aminocaproic acid, γ-aminobutyric acid, trimethylglycine, xylose, sorbitol, mannitol, butylene glycol, hexylene glycol, pentylene glycol, glycerin, and hinokitiol.

[0061] Other specific examples of active ingredients include fullerene, oryzanol, ceramide EOP, ceramide EOS, ceramide NG, caprooylsphingosine, ceramide NP, N-stearoylphytosphingosine, N-stearoyldihydrosphingosine, ceramide AG, ceramide AP, hydroxystearylphytosphingosine, ceramide 6II, phytosphingosine (whether liposome-encapsulated or not), flavonoids (isoflavones, licorice root extract, licorice flavonoids, licorice flavonoids, etc.), extracts obtained from plants or animals (chamomilla ET, Sophora Angustifolia root extract, Swertia japonica extract, carrot or its root extract, soybean extract, soybean seed extract, tea leaf extract, Galactomyces ferment broth, rice extract No. 11, astaxanthin solution, red algae extract, placenta extract, etc.), stem cell culture broth, stem cell culture supernatant, etc.

[0062] Other specific examples of active ingredients include squalane, linoleic acid, ascorbyl tetra-2-hexyldecanoate, ascorbyl dipalmitate, retinol or its derivatives (retinol acetate, retinol palmitate, hydrogenated retinol, retinol linoleate, etc.), tocopherol (natural vitamin E) or its derivatives (tocopherol nicotinate, dl-α-tocopherol, d-δ-tocopherol, DL-α-tocopherol acetate, etc.), and glutamic acid. Examples of suitable oils include stearyl rityrrhizinate, estradiol, ethinylestradiol, astaxanthin, rice germ oil, phospholipids (such as sphingomyelin), synthetic or plant-based squalane, guaiazulene, guaiazulene sulfonate ester, fatty acid esters of ascorbic acid (such as ascorbyl stearate and ascorbyl palmitate), di(phytosteryl / octyldodecyl) lauroyl glutamate, and oil-soluble placenta.

[0063] Other specific examples of active ingredients include human recombinant oligopeptide-1, palmitoyl hexapeptides (palmitoyl hexapeptide-4, etc.), palmitoyl pentapeptides, hydrolyzed collagen or a derivative thereof, hyaluronic acid or a derivative thereof (sodium hyaluronate, acetylated sodium hyaluronate), Tremella fuciformis polysaccharide, Alcaligenes-produced polysaccharide, polyquaterniums, etc. The bioadhesive layer 4 as described above can well retain such compounds.

[0064] Furthermore, the current that promotes the penetration of the active ingredient contained in the topical skin preparation may be an alternating current. For example, depending on the characteristics of the active ingredient, an alternating current (AC stimulation) of an appropriate frequency may be applied to the skin surface to promote the penetration of the active ingredient. When the active ingredient is a low-molecular-weight substance that is water-soluble and easily positively charged in aqueous solution (e.g., tranexamic acid), the frequency of the alternating current is preferably about 10 kHz or more and 200 kHz or less, and more preferably about 50 kHz or more and 180 kHz or less. When the active ingredient is a low-molecular-weight substance that is water-soluble and easily negatively charged in aqueous solution (e.g., 4-methoxysalicylic acid potassium salt), the frequency of the alternating current is preferably about 10 kHz or more and 200 kHz or less, and more preferably about 50 kHz or more and 160 kHz or less.

[0065] In addition, depending on the properties of the active ingredient, it may be possible to promote the penetration of the active ingredient into skin tissue by providing an appropriate stimulus, for example, when the active ingredient is a low-molecular-weight substance that is water-soluble and has the property of being almost uncharged in an aqueous solution (kojic acid, arbutin, etc.) or an ampholyte (amino acid, peptides), a lipid or oil-soluble substance (squalane, etc.), or a polymeric substance (human recombinant oligopeptide-1, etc.).

[0066] As shown in Figures 6 and 7, the bioadhesive layer 4 may be provided to correspond to the shape of the conductive pattern 3 in a planar view. Specifically, the shape of the bioadhesive layer 4 in a planar view may be the same as or slightly larger than the shape of the conductive pattern 3 in a planar view. Figure 6 is a plan view showing an exploded state of a conductive sheet having a bioadhesive layer with another configuration. Figure 7 is a cross-sectional view of the conductive sheet in Figure 6 corresponding to Figure 4. In the following description, the front side of the page in Figure 6 will also be referred to as the "front" or "top," the back side of the page in Figure 6 will also be referred to as the "back" or "bottom," the upper side in Figure 7 will also be referred to as the "front" or "top," and the lower side in Figure 7 will also be referred to as the "back" or "bottom."

[0067] With this configuration, when a topical skin preparation is used in combination, the topical skin preparation can be held in the slits 3a of the conductive pattern 3 and the slits 4a of the bioadhesive layer 4, preventing or suppressing scattering. In this state, if an electric current that promotes the penetration of the active ingredient contained in the topical skin preparation is supplied to the skin surface via the electrode section 32, the penetration efficiency of the active ingredient can be further improved. The skin treatment device 100 is configured such that the area of ​​the conductive sheet 1 in a plan view is A [mm ２ ], and the area of ​​the device body 10 in a plan view is B [mm ２ ], B / A is preferably about 0.1 or more and 0.6 or less, and more preferably about 0.2 or more and 0.5 or less. This allows for a balance between the size of the conductive sheet 1 and the size of the device main body 10. The bioadhesive layer 4 does not have to be provided to correspond to the shape of the conductive pattern 3 in a planar view, and may have, for example, a shape and / or size that covers the entire conductive pattern 3, or a shape and / or size that exposes a portion of the conductive pattern 3.

[0068] <Second Configuration Example> Next, a second configuration example of the conductive sheet 1 will be described. Hereinafter, the conductive sheet 1 of the second configuration example will be described, focusing on the differences from the conductive sheet 1 of the first configuration example, and similar points will not be described again. FIG. 8 is a plan view showing an exploded state of a skin treatment device including a conductive sheet of the second configuration example. In the following description, the front side of the page in FIG. 8 will be referred to as the "front" or "top," and the back side of the page in FIG. 8 will be referred to as the "back" or "bottom." In addition, in FIG. 8, the conductive pattern 3 located on the back side (lower side) of the sheet substrate 2 is indicated by diagonal lines.

[0069] The conductive sheet 1 of the second configuration example is elongated and is formed so that the width at one end is larger than the width at the other end. The device main body 10 is configured to be attached to one end of the conductive sheet 1. The conductive sheet 1 is also curved midway along its length. The conductive sheet 1 configured in this manner can be suitably used by adhering it to skin areas where the eyes or nasolabial folds are prominent. In this way, the user can select an appropriate conductive sheet 1 depending on the area of ​​the skin to be treated, and then attach and use the device main body 10, making it easier to more reliably perform skin treatment according to the user's needs.

[0070] <Third Configuration Example> Next, a third configuration example of the conductive sheet 1 will be described. Hereinafter, the conductive sheet 1 of the third configuration example will be described, focusing on the differences from the conductive sheet 1 of the first and second configuration examples, and a description of similar points will be omitted. FIG. 9 is a plan view showing the conductive sheet 1 of the third configuration example. In the following description, the front side of the paper in FIG. 9 will also be referred to as the "front" or "top," and the back side of the paper in FIG. 9 will also be referred to as the "back" or "bottom." In addition, in FIG. 9, the conductive pattern 3 located on the back side (lower side) of the sheet substrate 2 is shown with diagonal lines.

[0071] The conductive sheet 1 of the third configuration example is elongated and curved midway along its length to form a C- or L-shape. A conductive sheet 1 of this configuration can be brought into contact with, for example, the frontalis, temporalis, and orbicularis oculi muscle areas all at once, facilitating skin treatment for these areas. Furthermore, the tip 35 of each conductive pattern 3, opposite the connection 34, is mesh-shaped. Having such a tip 35 allows for the current applied to the skin surface to be dispersed in this area (in other words, preventing current concentration). As a result, the user can experience a mild sensation (muscle stimulation), i.e., a sensation that is not unpleasant.

[0072] <Fourth Configuration Example> Next, a fourth configuration example of the conductive sheet 1 will be described. Hereinafter, the conductive sheet 1 of the fourth configuration example will be described, focusing on the differences from the conductive sheets 1 of the first to third configuration examples, and a description of similar points will be omitted. FIG. 10 is a plan view showing the conductive sheet 1 of the fourth configuration example. In the following description, the front side of the page in FIG. 10 will also be referred to as the "front" or "top," and the back side of the page in FIG. 10 will also be referred to as the "back" or "bottom." In addition, in FIG. 10, the conductive pattern 3 located on the back side (lower side) of the sheet substrate 2 is shown with diagonal lines.

[0073] The conductive sheet 1 of the fourth configuration example is similar to the conductive sheet 1 of the third configuration example, except for the configuration of the tip of one of the conductive patterns 3. That is, in the conductive sheet 1 of the fourth configuration example, the tip 35a of one of the conductive patterns 3 is separated and independent. Therefore, electricity cannot flow through the tip 35a, and therefore, no current is supplied to the skin surface from the tip 35a. In this case, no current is supplied across the frontalis and temporalis muscles, thereby reducing the occurrence of pain.

[0074] <Fifth Configuration Example> Next, a fifth configuration example of the conductive sheet 1 will be described. Hereinafter, the conductive sheet 1 of the fifth configuration example will be described, focusing on the differences from the conductive sheets 1 of the first to fourth configuration examples, and similar points will not be described again. FIG. 11 is a bottom view showing the conductive sheet 1 of the fifth configuration example. In the following description, the front side of the page in FIG. 11 will also be referred to as the "back" or "bottom," and the back side of the page in FIG. 11 will also be referred to as the "front" or "top." The bioadhesive layer 4 is also omitted in FIG. 11. The conductive sheet 1 of the fifth configuration example includes a masking portion 5 provided so as to cover a portion of the sheet substrate 2 (conductive pattern 3), but is otherwise similar to the conductive sheet 1 of the fourth configuration example.

[0075] This masking portion 5 has at least one of the functions of blocking the current supplied to the user's skin surface and reducing the flexibility of the conductive sheet 1. For example, as shown in Fig. 11, the masking portion 5 can be configured with an insulating sheet provided so as to cover a portion of one conductive pattern 3 near the connection portion 34. With this configuration, the current supplied to the skin surface from near the connection portion 34 can be blocked, and the current can be preferentially supplied to the skin surface from the tip portion 35 side. In this way, by changing the portion of the conductive pattern 3 covered by the masking portion 5, it is possible to adjust the position where the user can easily obtain a physical sensation (muscle stimulation).

[0076] The masking portion 5 can also be made of a low-elasticity sheet. In this case, the conductive sheet 1 can have an elastic portion that is pulled to adhere to the skin surface, and a non-elastic portion that stably secures the positional relationship between the skin surface and the conductive pattern 3. In this case, the elastic portion can be a portion that needs to conform to the shape of the face (for example, a portion corresponding to a skin surface that is prone to wrinkles, etc.). On the other hand, the non-elastic portion can be a portion where muscle stimulation is desired to be reliably applied, etc.

[0077] <Sixth Configuration Example> Next, a sixth configuration example of the conductive sheet 1 will be described. Hereinafter, the conductive sheet 1 of the sixth configuration example will be described, focusing on the differences from the conductive sheets 1 of the first to fifth configuration examples, and similar points will not be described again. FIG. 12(a) is a plan view showing the conductive sheet 1 of the sixth configuration example, and FIG. 12(b) is a side view showing the conductive sheet 1 of the sixth configuration example. FIG. 13 is a cross-sectional view taken along line B-B in FIG. 12(a). In the following description, the front side of the page in FIG. 12(a) will also be referred to as the "front" or "top," the back side of the page in FIG. 12(a) will also be referred to as the "back" or "bottom," the upper side in FIG. 12(b) will also be referred to as the "front" or "top," and the lower side in FIG. 12(b) will also be referred to as the "back" or "bottom." The upper side in FIG. 13 will also be referred to as the "front" or "top," and the lower side in FIG. 13 will also be referred to as the "back" or "bottom." In FIG. 12, the conductive pattern 3 and the like located on the back side (lower side) of the sheet substrate 2 are indicated by dashed lines.

[0078] As shown in FIG. 13 , the sheet substrate 2 of the sixth configuration example includes a non-stretchable sheet substrate 201 and a stretchable sheet substrate 202, which are integrally formed. The sheet substrate 2 may be formed by separately preparing the non-stretchable sheet substrate 201 and the stretchable sheet substrate 202 and then joining them together using, for example, adhesive bonding, fusion (thermal fusion, high-frequency fusion, ultrasonic fusion), or an adhesive material. Examples of adhesive materials include an adhesive sheet 6, conductive tape 37, and additional adhesive tape. The non-stretchable sheet substrate 201 is preferably relatively hard. Materials for the non-stretchable sheet substrate 201 include, but are not limited to, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polyphenylene sulfide (PPS), and fluororesin. The non-stretchable sheet substrate 201 also has two through-holes 2011 formed therein.

[0079] A reinforcing block 24 is fixed to the upper surface of the non-stretchable sheet substrate 201. Two through holes 241 are formed in the reinforcing block 24, each opening at an opening 222. Each through hole 241 is connected to a corresponding through hole 2011. Two through holes 221 are also formed at predetermined positions in the reinforcing block 24. The device main body 10 is attached to this reinforcing block 24. The same materials as those listed for the non-stretchable sheet substrate 201 can be used as the constituent material for the reinforcing block 24. The stretchable sheet substrate 202 has high conformability to the skin surface and can accommodate skin movement, making it excellent for supporting the conductive pattern 3 serving as the skin electrode. The same materials as those listed for the sheet substrate 2 above can be used as the constituent material for the stretchable sheet substrate 202.

[0080] Two conductive patterns 3 are provided on the lower surface of the stretchable sheet substrate 202. A conductive tape 37 is connected to each of the two conductive patterns 3 at an electrical connection 38. The conductive tape 37 can be made of a resin tape in which conductive particles containing silver, gold, nickel, or the like are dispersed. A columnar connection 36 is fixed to the upper surface of each conductive tape 37. The connection 36 is preferably magnetic. An adhesive tape 6 is provided between each conductive tape 37 and the sheet substrate 2. Through holes 61 are formed in the adhesive tape 6. Examples of materials that can be used for the adhesive tape 6 include acrylic adhesives, urethane adhesives, silicone adhesives, natural rubber adhesives, and synthetic rubber adhesives. These adhesives may be used alone or in combination.

[0081] When the conductive sheet 1 is assembled, the connection portion 36 is inserted into the through-hole 241 via the through-hole 61 and the through-hole 2011. A masking tape 7 is provided on the underside of the conductive tape 37. The masking tape 7 can be made of the same materials as those listed for the non-stretchable sheet substrate 201. The bottom layer of the conductive sheet 1 is a bioadhesive layer 4. With this configuration, the connection portion 36 electrically connecting the terminal portion 11 of the device body 10 is reinforced with the non-stretchable sheet substrate 201, the reinforcing block 24, and the masking tape 7, ensuring a stable connection between the conductive sheet 1 and the device body 10. The device body 10 can also be easily removed from the conductive sheet 1. Meanwhile, the conductive pattern 3 is supported by the stretchable sheet substrate 202, allowing it to be attached with high conformability to the skin surface.

[0082] When the conductive sheets 1 of the second to sixth configuration examples were applied to the eye area for 10 minutes three times a week, four weeks of use significantly increased the thickness of the orbicularis oculi and temporalis muscles, and eight weeks of use significantly improved moisture and under-eye sagging. Age-related changes in the eyes often include sagging above and below the eyes, as well as wrinkles around the eyes. These age-related changes are known to be caused not only by physiological aging and photoaging, but also by the skin and the muscles around the eyes. It has been reported that the orbicularis oculi muscles, which form a doughnut shape around the eyes, thin with age, and drooping of the eyes is known to cause a loss of youthful appearance and age-related changes. Using the conductive sheet 1, which fits easily around the eyes, efficiently provides electrical stimulation to the muscles around the eyes, strengthening the orbicularis oculi and temporalis muscles, significantly improving sagging around the eyes.

[0083] Next, the conductive sheet of the present invention will be described. The conductive sheet 1 is used to supply current to a user's skin surface, and at least a portion of the conductive sheet 1 is stretchable in any direction or flexible enough to conform to the skin surface. This conductive sheet 1 includes a sheet substrate 2, a conductive pattern 3, and a bioadhesive layer 4. The conductive pattern 3 is provided on one side of the sheet substrate 2 and includes a wiring portion 31 and an electrode portion 32 connected to one end of the wiring portion 31. The bioadhesive layer 4 is provided on the side of the conductive pattern 3 opposite the sheet substrate 2 and is configured to be attached to the user's skin surface. The bioadhesive layer 4 is preferably in a gel form. The configurations of the sheet substrate 2, the conductive pattern 3, and the bioadhesive layer 4 are the same as those of the sheet substrate 2, the conductive pattern 3, and the bioadhesive layer 4 described in the skin treatment device of the present invention, respectively. Using this conductive sheet 1, skin treatment can be performed on various areas of the skin surface according to the user's needs. Furthermore, the conductive sheet 1 may be provided in the following forms.

[0084] (1) A skin treatment device comprising: a conductive sheet, at least a portion of which is stretchable in any direction, or a conductive sheet, at least a portion of which is flexible enough to conform to the skin surface; and a device body attached to the conductive sheet and supplying current to the skin surface of a user; the conductive sheet having a sheet base material, a conductive pattern, and a biological adhesive layer; the conductive pattern being provided on one side of the sheet base material and comprising a wiring section and an electrode section connected to one end of the wiring section; the biological adhesive layer being provided on the opposite side of the conductive pattern from the sheet base material and configured to be adhered to the skin surface of the user.

[0085] (2) The skin treatment device according to (1) above, wherein the bioadhesive layer is in a gel state.

[0086] (3) In the skin treatment device described in (1) or (2) above, the current is at least one of a current that promotes penetration of the active ingredient contained in the topical skin preparation, a current that provides muscle stimulation, a current that warms the skin surface, and a microcurrent.

[0087] (4) In the skin treatment device described in any one of (1) to (3) above, the device main body is detachably attached to the conductive sheet.

[0088] (5) A skin treatment device according to any one of (1) to (4) above, wherein the device body is attached to the conductive sheet by magnetic force.

[0089] (6) The skin treatment device according to (4) or (5) above, further comprising a plurality of different types of conductive sheets, and the device body is detachably attached to each of the conductive sheets.

[0090] (7) The skin treatment device according to any one of (4) to (6) above, further comprising a positioning portion for positioning the device body relative to the conductive sheet.

[0091] (8) A skin treatment device according to any one of (1) to (7) above, wherein the device main body further has a pair of terminal portions, and the wiring portion has a connection portion at the other end thereof that is connected to one of the terminal portions.

[0092] (9) The skin treatment device according to (8) above, wherein the sheet substrate has an opening through which the connection portion is exposed.

[0093] (10) A skin treatment device according to any one of (1) to (9) above, wherein the wiring section and a portion of the electrode section are arranged along the outer edge of the sheet substrate.

[0094] (11) A skin treatment device according to any one of (1) to (10) above, wherein the conductive sheet is elongated and the device main body is attached to the center or end of the conductive sheet in the longitudinal direction.

[0095] (12) In the skin treatment device described in any one of (1) to (10) above, the conductive sheet is elongated and formed so that the width of one end is larger than the width of the other end, and the device main body is attached to the one end side of the conductive sheet.

[0096] (13) The skin treatment device according to (11) or (12) above, wherein the conductive sheet is curved midway along its longitudinal direction.

[0097] (14) In the skin treatment device described in (13) above, the conductive sheet is C-shaped or L-shaped.

[0098] (15) In the skin treatment device according to any one of (1) to (14), the area of ​​the conductive sheet in a plan view is A [mm ２ ], and the area of ​​the device body in a plan view is B [mm ２ ], wherein B / A is 0.1 or more and 0.6 or less.

[0099] (16) A skin treatment device according to any one of (1) to (15) above, wherein the bioadhesive layer is provided to correspond to the shape of the conductive pattern in a planar view.

[0100] (17) A skin treatment device according to any one of (1) to (16) above, wherein the resistance of the entire conductive pattern and the bioadhesive layer, or the conductive pattern alone, when not stretched is 1000 Ω or less.

[0101] (18) In the skin treatment device described in any one of (1) to (17) above, the conductive sheet further includes a masking portion arranged to cover a portion of the sheet base material, and the masking portion has at least one of the functions of blocking the current supplied to the skin surface of the user and reducing the elasticity of the conductive sheet.

[0102] (19) A conductive sheet used to supply electric current to the skin surface of a user, at least a portion of which is stretchable in any direction, or at least a portion of which is flexible enough to conform to the skin surface, comprising a sheet base material, a conductive pattern, and a bioadhesive layer, the conductive pattern being provided on one side of the sheet base material and comprising a wiring section and an electrode section connected to one end of the wiring section, the bioadhesive layer being provided on the opposite side of the conductive pattern from the sheet base material and configured to be adhered to the skin surface of the user.

[0103] (20) The conductive sheet according to (19) above, wherein the bioadhesive layer is in a gel state. Of course, this is not a limitation.

[0104] As described above, various embodiments of the present invention have been described, but these are presented as examples and do not limit the scope of the invention in any way. The novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are within the scope and spirit of the invention, and are also within the scope of the invention and its equivalents as set forth in the claims. In other words, the present invention is not limited to the above-described embodiments, and can be embodied in a suitable shape and treatment method depending on the wrinkles on the skin surface, the shape of the skin surface at the application position, the skin condition, and the active ingredients used.

[0105] For example, a film heater may be disposed between the sheet substrate 2 and the bioadhesive layer 4. In this case, by electrically connecting a portion of the conductive pattern 3 to a portion of the film heater, current (power) can be supplied to the film heater. This allows the skin surface to be warmed by the film heater during use of the skin treatment device 100. Furthermore, a magnetic layer may be disposed between the sheet substrate 2 and the bioadhesive layer 4. In this case, by electrically connecting a portion of the conductive pattern 3 to a portion of the magnetic layer, current (power) can be supplied to the magnetic layer. This allows the magnetic force of the magnetic layer to promote blood circulation during use of the skin surface. Such a magnetic layer can be created by printing magnetic ink or by forming a pattern containing magnetic powder. Furthermore, a magnetic conductive pattern 3 may be formed by using a magnetic conductive filler.

[0106] Furthermore, the configurations of the conductive sheet 1 and the device body 10 are not limited to those of the above-described embodiment. For example, the device body 10 may be provided with a plurality of terminal portions (power contacts) 11 so that a current (power) can be supplied from one device body 10 to a plurality of conductive sheets 1.

[0107] 100: Skin treatment device, 1: Conductive sheet, 2: Sheet base material, 201: Non-stretchable sheet base material, 2011: Through hole, 202: Stretchable sheet base material, 21: Wide portion, 22: Narrow portion, 221: Through hole, 222: Opening, 23: Ear portion, 24: Reinforcement block, 241: Through hole, 3: Conductive pattern, 3a: Slit, 31: Wiring portion, 32: Electrode portion, 33: Junction portion, 34: Connection portion, 35: Tip portion, 35a: Tip portion, 36: Connection portion, 37: Conductive tape, 38: Electrical connection portion, 4: Bioadhesive layer, 4a: Slit, 5: Masking portion, 6: Adhesive tape, 61: Through hole, 7: Masking tape, 10: Device body, 101: Pin, 11: Terminal portion, 12: Operation button, 13: Power supply unit, 14: Control unit, 15: Electric circuit unit

Claims

1. A skin treatment device, comprising: A conductive sheet at least a part of which is stretchable in any direction, or a conductive sheet at least a part of which has flexibility so that it can conform to the skin surface, and a device body that is attached to the conductive sheet and supplies an electric current to the skin surface of a user, The conductive sheet has a sheet base material, a conductive pattern, a bioadhesive layer, and a masking portion, The conductive pattern is provided on one surface of the sheet base material, the bioadhesive layer is provided on the opposite side of the conductive pattern to the sheet base material, and is configured to be attached to the skin surface of the user; The masking portion is non-removably arranged to cover a portion of the sheet base material, and has at least one of the functions of blocking the current supplied to the user's skin surface and reducing the elasticity of the conductive sheet.

2. The skin treatment device according to claim 1, The skin treatment device, wherein the bioadhesive layer is in a gel state.

3. The skin treatment device according to claim 1, The current is at least one of a current that promotes the penetration of an active ingredient contained in a skin topical preparation, a current that imparts muscle stimulation, a current that warms the skin surface, and a microcurrent.

4. The skin treatment device according to claim 1, The device body is detachably attached to the conductive sheet.

5. The skin treatment device according to claim 1, The device body is attached to the conductive sheet by magnetic force.

6. The skin treatment device according to claim 4, A plurality of different types of conductive sheets are provided, The device body is detachably attached to each of the conductive sheets.

7. The skin treatment device according to claim 4, The skin treatment device further comprises a positioning portion of the device body relative to the conductive sheet.

8. The skin treatment device according to claim 1, The device body further has a pair of terminal portions, The conductive pattern of the skin treatment device has a wiring portion, an electrode portion connected to one end of the wiring portion, and a connection portion connected to the other end of the wiring portion and connected to one of the terminal portions.

9. The skin treatment device according to claim 8, The sheet base material has an opening through which the connection portion is exposed.

10. The skin treatment device according to claim 8 or 9, A skin treatment device, wherein the wiring portion and a portion of the electrode portion are arranged along an outer edge of the sheet base material.

11. The skin treatment device according to claim 1, The conductive sheet has an elongated shape, The device body is attached to the center or end of the conductive sheet in the longitudinal direction of the skin treatment device.

12. The skin treatment device according to claim 1, The conductive sheet is elongated and is formed so that the width of one end side is larger than the width of the other end side, The device body is a skin treatment device attached to the one end side of the conductive sheet.

13. The skin treatment device according to claim 11 or 12, The conductive sheet is curved midway in its longitudinal direction to form a C-shape or an L-shape.

14. The skin treatment device according to claim 1, The area of ​​the conductive sheet in a plan view is A [mm ２ ], and the area of ​​the device body in a plan view is B [mm ２ ], B / A is 0.1 or more and 0.6 or less.

15. The skin treatment device according to claim 1, A skin treatment device, wherein the resistance value of the conductive pattern and the bioadhesive layer as a whole, or the conductive pattern alone, when not stretched is 1000 Ω or less.

16. A skin treatment device comprising: A conductive sheet at least a part of which is stretchable in any direction, or a conductive sheet at least a part of which has flexibility so that it can conform to the skin surface, and a device body that is attached to the conductive sheet and supplies an electric current to the skin surface of a user, The conductive sheet has a sheet base material, a conductive pattern, and a bioadhesive layer, the conductive pattern is provided on one surface side of the sheet base material, and includes a plurality of wiring portions and a junction portion formed by merging the plurality of wiring portions and having a width greater than that of each of the wiring portions; The bioadhesive layer is provided on the opposite side of the conductive pattern to the sheet substrate, and is configured to be attached to the skin surface of the user.

17. The skin treatment device according to claim 16, A skin treatment device, wherein a portion of the wiring portion is in a mesh shape at an end opposite the junction portion.

18. A conductive sheet used to supply an electric current to a user's skin surface, at least a part of which is stretchable in any direction, or at least a part of which is flexible enough to conform to the skin surface, The sheet has a sheet base material, a conductive pattern, a bioadhesive layer, and a masking portion, The conductive pattern is provided on one surface of the sheet base material, the bioadhesive layer is provided on the opposite side of the conductive pattern to the sheet base material, and is configured to be attached to the skin surface of the user; The masking portion is non-removably provided so as to cover a portion of the sheet base material, and has at least one of the functions of blocking the current supplied to the skin surface of the user and reducing the elasticity of the conductive sheet.

19. The conductive sheet according to claim 18, The conductive sheet, wherein the bioadhesive layer is in a gel state.

20. A conductive sheet used to supply electric current to a user's skin surface, at least a portion of which is stretchable in any direction, or at least a portion of which is flexible enough to conform to the skin surface, The sheet has a sheet substrate, a conductive pattern, and a bioadhesive layer, the conductive pattern is provided on one surface side of the sheet base material, and includes a plurality of wiring portions and a junction portion formed by merging the plurality of wiring portions and having a width greater than that of each of the wiring portions; The conductive sheet, wherein the bioadhesive layer is provided on the opposite side of the conductive pattern to the sheet substrate and is configured to be attached to the skin surface of the user.

21. The conductive sheet according to claim 20, A conductive sheet, wherein a portion of the wiring portion is in a mesh shape at an end portion opposite the junction portion.