Skin-contact patch, adhesive layer, and skin-contact patch sheet

Abstract

To provide a patch for skin-to-skin bonding and an adhesive layer that achieve bonding between skins with suppressed irritation and can exhibit excellent skin-to-skin bonding for a long period of time even under conditions where salt and oil coexist on the skin in abundance.SOLUTION: A patch for skin-to-skin bonding comprises fine resin particles (A) and an aqueous medium. The fine resin particles (A) have a glass transition temperature of -60°C to -10°C and an acid value of 3.0 to 40.0 mgKOH / g. The fine resin particles (A) are a polymer of an ethylenically unsaturated monomer mixture containing an ethylenically unsaturated monomer (a-1) and an ethylenically unsaturated monomer (a-2). In 100 mass% of the ethylenically unsaturated monomer mixture, the content of the ethylenically unsaturated monomer (a-1) is 2.0 to 40.0 mass%, the content of the ethylenically unsaturated monomer (a-2) is 20.0 to 97.5 mass%, and the surface tension thereof at 25°C is 25.0 to 50.0 mN / m.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a patch and adhesive layer that are applied directly to the skin to form an adhesive layer that bonds skin to skin, and also to a patch sheet for indirect skin application that is used to form an adhesive layer that bonds skin to skin. [Background technology]

[0002] Due to the recent COVID-19 pandemic, situations in which people wear protective equipment such as masks, gloves, and goggles for long periods of time have become more common. Wearing such protective equipment causes large amounts of sweat containing salt and sebum containing oil to be secreted onto the skin, which can quickly degrade the performance of patches applied to the skin. Patches used for skin-to-skin adhesion, such as those used in medical, cosmetic, and special makeup applications, are particularly susceptible to salt and oil secretions from both sides of the skin, making it difficult to maintain excellent adhesion for long periods of time in environments where these substances are abundant. Furthermore, these patches must be designed to minimize skin damage and irritation.

[0003] Patent Document 1 discloses a skin patch containing a mixture of rubber latex and an acrylic resin emulsion. Patent Document 2 discloses a skin patch containing an acrylic resin emulsion and modified cornstarch. Patent Document 3 discloses a skin patch containing an acrylic resin emulsion consisting of 2-ethylhexyl acrylate and methacrylic acid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-208076 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-024762 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-199695 Summary of the Invention [Problem to be solved by the invention]

[0005] However, these conventional skin patches have poor resistance to salt and oil, and their adhesiveness to the skin deteriorates in a short time, especially under harsh conditions where salt and oil coexist in abundance. They also have the problem of easily causing allergies and causing skin irritation when applied for long periods of time.

[0006] The present invention aims to provide a patch and adhesive layer for indirect skin application that combines excellent skin adhesion and suppression of skin irritation, and that can maintain excellent skin adhesion for a long period of time even under harsh conditions such as the coexistence of abundant salt and oil on the skin. [Means for solving the problem]

[0007] The present invention comprises resin fine particles (A) and an aqueous medium, The present invention relates to an indirectly applied patch for skin application, wherein the resin microparticles (A) have a glass transition temperature of -60 to -10°C and an acid value of 3.0 to 40.0 mgKOH / g, and are a polymer of an ethylenically unsaturated monomer mixture containing the following ethylenically unsaturated monomer (a-1) and the following ethylenically unsaturated monomer (a-2), wherein the content of the ethylenically unsaturated monomer (a-1) is 2.0 to 40.0 mass% and the content of the ethylenically unsaturated monomer (a-2) is 20.0 to 97.5 mass% in 100 mass% of the ethylenically unsaturated monomer mixture, and the surface tension at 25°C is 25.0 to 50.0 mN / m. (a-1): A nonionic ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 0.4 or more and less than 2.0. (a-2): An ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 2.0 or more and less than 2.5.

[0008] The present invention also relates to the above-mentioned indirect skin patch, wherein the total content of the ethylenically unsaturated monomer (a-1) and the ethylenically unsaturated monomer (a-2) is 40.0 to 99.5% by mass in 100% by mass of the above-mentioned ethylenically unsaturated monomer mixture.

[0009] In addition, the adhesive layer formed from the patch for indirect skin application of the present invention is The patch for indirect skin application has an elution rate of 50.0 to 100.0% by mass when immersed in ethyl acetate at 50° C. for 24 hours.

[0010] The present invention also relates to the above-mentioned transdermal patch, wherein the ethylenically unsaturated monomer (a-1) comprises at least one ethylenically unsaturated monomer selected from the group consisting of methoxyethyl acrylate, methyl acrylate, and methyl methacrylate.

[0011] The present invention also relates to the above-mentioned transdermal patch, wherein the ethylenically unsaturated monomer (a-2) includes at least one of n-butyl acrylate and phenoxyethyl acrylate.

[0012] The present invention also relates to an adhesive layer formed from the above-mentioned patch for indirect skin application.

[0013] The present invention also relates to a patch sheet for indirect skin wear comprising a releasable substrate and the above adhesive layer. [Effects of the Invention]

[0014] The present invention makes it possible to provide a patch and adhesive layer for indirect skin application that achieve both excellent adhesion between the skin and suppression of skin irritation, and that can maintain excellent adhesion between the skin for a long period of time even under harsh conditions such as the coexistence of abundant salt and oil on the skin.

[0015] Hereinafter, an embodiment of the present invention will be described. In this specification, the nonionic ethylenically unsaturated monomer (a-1) having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 0.4 or more and less than 2.0, and the ethylenically unsaturated monomer (a-2) having a logarithm of the octanol / water partition coefficient (Log Kow) of 2.0 or more and less than 2.5 may be abbreviated as the ethylenically unsaturated monomer (a-1) and the ethylenically unsaturated monomer (a-2), respectively.

[0016] The octanol / water partition coefficient (Log Kow) is expressed by the following formula (1), and is used as an index to indicate whether a certain compound X is more likely to partition into the water phase or the oil phase (octanol). The Log Kow of each ethylenically unsaturated monomer can be calculated from experiments such as the shake flask method or HPLC method, or it can be calculated from a simulation based on the chemical structure, such as the YMB method (physical property prediction function) in the Hansen solubility parameter software HSPiP. (Formula 1) Log Kow = Log (concentration of compound X in the octanol phase / concentration of compound X in the aqueous phase) The various components appearing in this specification are not limited to these examples, and unless otherwise noted, each may be used independently as a single type or in combination of two or more types.

[0017] <<Patches for indirect application to the skin>> The patch for indirect skin application of the present invention is applied directly to the skin and is used for adhesion between skin layers. The patch for indirect skin application contains resin fine particles (A) and an aqueous medium, and has a surface tension at 25°C of 25.0 to 50.0 mN / m. The resin microparticles (A) have a glass transition temperature of -60 to -10°C and an acid value of 3.0 to 40.0 mgKOH / g, and are a polymer of an ethylenically unsaturated monomer mixture containing the following ethylenically unsaturated monomer (a-1) and the following ethylenically unsaturated monomer (a-2), wherein the content of the ethylenically unsaturated monomer (a-1) is 2.0 to 40.0 mass%, and the content of the ethylenically unsaturated monomer (a-2) is 20.0 to 97.5 mass%, based on 100 mass% of the ethylenically unsaturated monomer mixture. (a-1): A nonionic ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 0.4 or more and less than 2.0. (a-2): An ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 2.0 or more and less than 2.5. This allows the adhesive to be applied to both skin and to suppress skin irritation, and also allows the adhesive to maintain excellent adhesion to skin for a long period of time even under harsh conditions where there is an abundance of salt and oil on the skin.

[0018] The surface tension of the indirect skin patch at 25°C is 25.0 to 50.0 mN / m, preferably in the range of 28.0 to 40.0 mN / m. Having a surface tension in the above range improves the wettability and permeability of the indirect skin patch to the skin, and also improves the film-forming properties between the resins. As a result, excellent adhesion is exhibited to the skin, and the patch is also excellent in saltwater resistance, oil resistance, and durability under conditions where saltwater and oil coexist. Skin irritation can also be reduced. The surface tension value can be determined by the plate method (Wilhelmy method).

[0019] The adhesive layer formed from the indirect skin patch preferably has an elution rate of 50.0 to 100.0 mass %, more preferably 60.0 to 100.0 mass %, when immersed in ethyl acetate at 50°C for 24 hours. A elution rate within the above range improves the anchoring ability to the skin, further improves adhesion between the skin, and also improves saltwater resistance, oil resistance, and durability under conditions where saltwater and oil coexist. Skin irritation is also reduced.

[0020] The content of the resin microparticles (A) contained in the patch for indirect skin contact is preferably 20.0 to 60.0 mass %, more preferably 30.0 to 58.0 mass %, based on 100 mass % of the patch for indirect skin contact. By containing the resin microparticles in the above range, unevenness in the applied adhesive layer is reduced, and better adhesion to the skin can be achieved.

[0021] <Aqueous medium> An aqueous medium refers to an aqueous dispersion medium or an aqueous solvent. Although water is preferably used as the aqueous medium, water-soluble solvents can also be used if necessary, such as alcohols, glycols, cellosolves, amino alcohols, amines, ketones, carboxylic acid amides, phosphoric acid amides, sulfoxides, carboxylic acid esters, phosphoric acid esters, ethers, and nitriles.

[0022] <Resin fine particles (A)> The resin fine particles (A) have a glass transition temperature of -60 to -10°C and an acid value of 3.0 to 40.0 mgKOH / g. The present invention is also a polymer of an ethylenically unsaturated monomer mixture containing the following ethylenically unsaturated monomers (a-1) and (a-2), in which the content of the ethylenically unsaturated monomer (a-1) is 2.0 to 40.0 mass% and the content of the ethylenically unsaturated monomer (a-2) is 20.0 to 97.5 mass% in 100 mass% of the ethylenically unsaturated monomer mixture.

[0023] The ethylenically unsaturated monomers constituting the resin fine particles (A) are classified into the following ethylenically unsaturated monomers (a-1) to (a-3), and the resin fine particles (A) may contain, in addition to the ethylenically unsaturated monomers (a-1) and (a-2), other ethylenically unsaturated monomers (a-3) as needed. (a-1): A nonionic ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 0.4 or more and less than 2.0. (a-2): An ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 2.0 or more and less than 2.5. (a-3): Other ethylenically unsaturated monomers

[0024] The glass transition temperature (Tg) of the resin fine particles (A) is in the range of −60 to −10° C., more preferably −40 to −15° C. By having a Tg within the above range, the patch for indirect skin application can be sufficiently wetted and anchored to the skin surface, thereby exhibiting excellent adhesiveness.

[0025] The acid value of the resin microparticles (A) is in the range of 3.0 to 40.0 mgKOH / g, more preferably 5.0 to 30.0 mgKOH / g. By having an acid value in this range, the carboxy groups in the resin microparticles (A) interact sufficiently with the functional groups on the skin surface, improving the adhesion between the particles and the skin. Furthermore, the interaction between the carboxy groups between the particles also improves the coating strength, resulting in excellent adhesion between the particles and the skin, as well as excellent resistance to saltwater and oil, and durability under conditions where saltwater and oil coexist.

[0026] [Ethylenically unsaturated monomer (a-1)] The ethylenically unsaturated monomer (a-1) is a nonionic ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 0.4 or more and less than 2.0. The Log Kow is preferably 0.45 or more and less than 1.3. When the Log Kow is in the above range, the patch exhibits good adhesion to the skin and is also excellent in salt water resistance and oil resistance. The nonionic ethylenically unsaturated monomer is an ethylenically unsaturated monomer that does not have a charged functionality when in an aqueous medium, such as an ethylenically unsaturated monomer that does not have an amino group, a carboxyl group, or a sulfonyl group.

[0027] The content of the ethylenically unsaturated monomer (a-1) is 2.0 to 40.0% by mass, more preferably 10.0 to 30.0% by mass, based on the total mass (100% by mass) of the ethylenically unsaturated monomer mixture. By being in the above range, the copolymerization with the ethylenically unsaturated monomer (a-2) and other ethylenically unsaturated monomers (a-3) is excellent, and the patch exhibits good adhesion to the skin while also exhibiting excellent resistance to salt water, oil, and durability under conditions where salt water and oil coexist. Furthermore, skin irritation is also low.

[0028] Examples of the ethylenically unsaturated monomer (a-1) include methoxyethyl acrylate (Log Kow=0.45), methyl acrylate (Log Kow=0.65), methoxyethyl methacrylate (Log Kow=1.15), 2-hydroxyethyl methacrylate (Log Kow=0.7), 4-hydroxybutyl acrylate (Log Kow=0.56), isopropyl acrylamide (Log Kow=0.54), diacetone acrylamide (Log Kow=0.84), 2-acetoacetoxyethyl methacrylate (Log Kow=0.61), glycidyl methacrylate (Log Kow=0.95), 3,4-epoxycyclohexyl acrylate (Log Kow=1.78), vinyl acetate (Log Kow=0.65), methyl methacrylate (Log Kow=1.13), ethyl acrylate (Log Kow=1.16), ethyl methacrylate (Log Kow=0.56), and the like. Examples of ethylenically unsaturated monomers include methyl acrylate (Log Kow=1.78), trifluoroethyl acrylate (Log Kow=1.57), trifluoromethacrylate (Log Kow=1.95), and ethylene glycol dimethacrylate (Log Kow 1.90). Among these, from the viewpoints of less irritation to the skin surface and exhibiting better adhesion and excellent saltwater resistance and oil resistance, it is preferable to contain at least one ethylenically unsaturated monomer selected from the group consisting of methoxyethyl acrylate, methyl acrylate, and methyl methacrylate. From the viewpoint of achieving better saltwater resistance, oil resistance, and durability against a mixture of saltwater and oil, the content of methoxyethyl acrylate, methyl acrylate, and methyl methacrylate is preferably 50 to 100 mass%, and more preferably 80 to 100 mass%, of 100 mass% of the ethylenically unsaturated monomer (a-1).

[0029] [Ethylenically unsaturated monomer (a-2)] The ethylenically unsaturated monomer (a-2) is an ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 2.0 or more and less than 2.5. The Log Kow is preferably 2.2 or more and less than 2.5. When the Log Kow is in the above range, the patch exhibits good adhesion to the skin even in the coexistence of salt water or oil.

[0030] The content of the ethylenically unsaturated monomer (a-2) is 20.0 to 97.5% by mass, more preferably 40.0 to 90.0% by mass, based on the total mass (100% by mass) of the ethylenically unsaturated monomer mixture. By being in the above range, copolymerization with the ethylenically unsaturated monomer (a-1) and other ethylenically unsaturated monomers (a-3) is excellent, and the patch exhibits good adhesion to the skin while also exhibiting excellent saltwater resistance, oil resistance, and durability under conditions where saltwater and oil coexist.

[0031] The total content of the ethylenically unsaturated monomer (a-1) and the ethylenically unsaturated monomer (a-2) is preferably 40.0 to 99.5% by mass, more preferably 50.0 to 96.5% by mass, based on 100% by mass of the total mass of the ethylenically unsaturated monomer mixture. When the content is within the above range, adhesion to skin is further improved, and saltwater resistance and oil resistance are also further improved.

[0032] Examples of the ethylenically unsaturated monomer (a-2) include t-butyl acrylate (Log Kow=2.06), n-butyl acrylate (Log Kow=2.23), n-propyl methacrylate (Log Kow=2.28), benzyl acrylate (Log Kow=2.32), phenoxyethyl acrylate (Log Kow=2.44), phenoxydiethylene glycol acrylate (Log Kow=2.12), 3-(methacryloyloxy)propyltrimethoxysilane (Log Kow=2.42), etc. Among these, it is preferable to include at least one of n-butyl acrylate and phenoxyethyl acrylate from the viewpoints of high affinity with the skin surface, better adhesion, excellent saltwater resistance, oil resistance, and durability under conditions where saltwater and oil coexist. The content of n-butyl acrylate or phenoxyethyl acrylate is preferably 50 to 100 mass%, and more preferably 80 to 100 mass%, of 100 mass% of the ethylenically unsaturated monomer (a-2), from the viewpoint of achieving better adhesion to skin, saltwater resistance, oil resistance, and durability under conditions where saltwater and oil coexist.

[0033] [Ethylenically unsaturated monomer (a-3)] The ethylenically unsaturated monomer (a-3) is another ethylenically unsaturated monomer polymerizable with the above-mentioned ethylenically unsaturated monomer (a-1) and the ethylenically unsaturated monomer (a-2), and is an ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of less than 0.4 or 2.5 or more, or an ionic ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 0.4 or more but less than 2.0.

[0034] Examples of the ethylenically unsaturated monomer (a-3) include aromatic ethylenically unsaturated monomers such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, vinylnaphthalene, benzyl methacrylate, and phenoxyethyl methacrylate; Ethylenically unsaturated monomers having a linear or branched alkyl group, such as hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, and behenyl (meth)acrylate; Ethylenically unsaturated monomers having an alicyclic group, such as cyclohexyl methacrylate and isobornyl (meth)acrylate; Ethylenically unsaturated monomers having a fluorinated alkyl group, such as heptadecafluorodecyl (meth)acrylate; Ethylenically unsaturated monomers having a nitrile group, such as (meth)acrylonitrile; Ethylenically unsaturated monomers having a carboxy group, such as (anhydride) maleic acid, fumaric acid, itaconic acid, citraconic acid, or alkyl or alkenyl monoesters thereof, succinic acid β-(meth)acryloxyethyl monoester, acrylic acid, methacrylic acid, crotonic acid, and cinnamic acid; Ethylenically unsaturated monomers having a sulfonic acid group, such as sodium 2-acrylamido-2-methylpropanesulfonate, methallylsulfonic acid, sodium methallylsulfonate, allylsulfonic acid, sodium allylsulfonate, ammonium allylsulfonate, and vinylsulfonic acid; (Meth)acrylamide, N-methoxymethyl-(meth)acrylamide, Ethylenically unsaturated monomers having an amide group, such as N-ethoxymethyl-(meth)acrylamide; Ethylenically unsaturated monomers having a hydroxyl group, such as 2-hydroxyethyl acrylate; Ethylenically unsaturated monomers having a polyoxyethylene group, such as methoxypolyethylene glycol (meth)acrylate and polyethylene glycol (meth)acrylate; Ethylenically unsaturated monomers having an amino group, such as dimethylaminostyrene, diethylaminostyrene, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and methylethylaminoethyl (meth)acrylate; etc.

[0035] As the ethylenically unsaturated monomer (a-3), in consideration of polymerization stability in an aqueous medium with the ethylenically unsaturated monomer (a-1) and the ethylenically unsaturated monomer (a-2) and the expression of good physical properties, n-octyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, isodecyl acrylate, methacrylic acid, acrylic acid, acrylamide, or 2-hydroxyethyl acrylate is preferred, and 2-ethylhexyl acrylate, methacrylic acid, or acrylic acid is more preferred.

[0036] When the ethylenically unsaturated monomer (a-3) is used in combination, the content of the ethylenically unsaturated monomer (a-3) is preferably 0.4 to 60.0 mass% and more preferably 1.0 to 20.0% relative to the total mass of the ethylenically unsaturated monomer mixture (100 mass%), so as not to impair the effects of the present invention. By being in the above range, it is possible to exhibit better adhesion, saltwater resistance, oil resistance, and durability under conditions where saltwater and oil coexist.

[0037] [Method for synthesizing resin particles (A)] Methods for synthesizing the resin fine particles (A) include solution polymerization, emulsion polymerization, and bulk polymerization, but emulsion polymerization is preferred from the viewpoints of controllability of reaction heat and not using organic solvents that may irritate the skin.

[0038] The emulsion polymerization is preferably carried out in the presence of at least a surfactant. Examples of the surfactant include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants. Among these, anionic surfactants, cationic surfactants, and nonionic surfactants are preferred, and anionic surfactants and nonionic surfactants are more preferred. The surfactant may be a reactive surfactant or a non-reactive surfactant.

[0039] Examples of non-reactive anionic surfactants include higher fatty acid salts such as sodium oleate, alkylarylsulfonates such as dodecylbenzenesulfonic acid, alkyl sulfates such as sodium lauryl sulfate, polyoxyethylene alkyl ether sulfates such as sodium polyoxyethylene lauryl ether sulfate, alkyl sulfosuccinates such as sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, and sodium polyoxyethylene lauryl sulfosuccinate, and derivatives thereof, and polyoxyethylene distyrenated phenyl ether sulfates.

[0040] Examples of non-reactive nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether, polyoxyethylene alkyl phenyl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether, sorbitan higher fatty acid esters such as sorbitan monolaurate, sorbitan monostearate, and sorbitan trioleate, polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate and polyoxyethylene sorbitan monostearate, polyoxyethylene higher fatty acid esters such as polyoxyethylene monolaurate and polyoxyethylene monostearate, glycerin higher fatty acid esters such as oleic acid monoglyceride and stearic acid monoglyceride, polyoxyethylene-polyoxypropylene block copolymers, and polyoxyethylene distyrenated phenyl ether.

[0041] The reactive surfactant is an anionic surfactant or a nonionic surfactant having one or more unsaturated double bonds capable of radical polymerization. The reactive anionic surfactant preferably has a main skeleton such as a sulfosuccinate ester, an alkyl ether, an alkylphenyl ether, an alkylphenyl ester, a (meth)acrylate sulfate ester, or a phosphate ester. The reactive nonionic surfactant preferably has a main skeleton such as alkyl ether, alkyl phenyl ether, or alkyl phenyl ester.

[0042] The surfactant is preferably used in an amount of 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the ethylenically unsaturated monomer mixture. By using an appropriate amount of surfactant, polymerization stability is improved and adverse effects on the skin are reduced.

[0043] For emulsion polymerization, it is preferable to use a radical polymerization initiator (hereinafter also simply referred to as "polymerization initiator"). As the polymerization initiator, known oil-soluble polymerization initiators or water-soluble polymerization initiators can be used. Examples of the oil-soluble initiator include organic peroxides such as benzoyl peroxide, tert-butyloxybenzoate, tert-butyl hydroperoxide, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxy-3,5,5-trimethylhexanoate, di-tert-butyl peroxide, cumene hydroperoxide, and p-menthane hydroperoxide; and azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), and 1,1'-azobis-cyclohexane-1-carbonitrile. Examples of the water-soluble polymerization initiator include ammonium persulfate, sodium persulfate, potassium persulfate, hydrogen peroxide, and 2,2'-azobis(2-methylpropionamidine) dihydrochloride.

[0044] When carrying out the polymerization, a reducing agent or a transition metal salt can be used in combination with the polymerization initiator, which accelerates the decomposition of the polymerization initiator. Examples of reducing agents include organic reducing compounds such as ascorbic acid, erythorbic acid, tartaric acid, citric acid, glucose, and metal salts of formaldehyde sulfoxylate, and inorganic reducing compounds such as sodium sulfite, sodium bisulfite, sodium metabisulfite, and sodium hyposulfite. Examples of transition metal salts include ferrous chloride, ferrous sulfate, and copper sulfate.

[0045] A water-soluble polymerization initiator is preferably used for the emulsion polymerization of the present invention. The polymerization initiator is preferably used in an amount of 0.03 to 5 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer mixture. The reducing agent is preferably used in an amount of 0.01 to 2.5 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer mixture. The transition metal salt is preferably used in an amount of 0.0001 to 0.002 parts by mass relative to 100 parts by mass of the ethylenically unsaturated monomer mixture. The polymerization initiator may be added, for example, by initial lump-sum addition, divided addition, or continuous dropwise addition, but is not particularly limited thereto. Furthermore, in order to hasten the end point of the polymerization reaction, a portion of the polymerization initiator may be added to the reaction system before or after the completion of the addition of the monomers to the reaction system.

[0046] During emulsion polymerization, a buffering agent, a chain transfer agent, a basic compound, etc. may be used as necessary. Examples of buffering agents include sodium acetate, sodium citrate, and sodium bicarbonate. Examples of chain transfer agents include n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, lauryl mercaptan, stearyl mercaptan, 3-mercaptopropionic acid, n-octyl 3-mercaptopropionate, 2-ethylhexyl 3-mercaptopropionate, n-octyl thioglycolate, 2-ethylhexyl thioglycolate, etc. Among these, 2-ethylhexyl 3-mercaptopropionate and 2-ethylhexyl thioglycolate are preferred, and 2-ethylhexyl thioglycolate is more preferred. The chain transfer agent is preferably used in an amount of 0.01 to 0.1 part by mass per 100 parts by mass of the ethylenically unsaturated monomer mixture. The basic compound used for neutralization includes, for example, alkylamines such as trimethylamine, triethylamine, and n-butylamine; alcoholamines such as 2-dimethylaminoethanol, diethylaminoethanol, diethanolamine, triethanolamine, and aminomethylpropanol; morpholine; and ammonia. The basic compound is preferably ammonia in view of its volatility when drying the adhesive.

[0047] Examples of emulsion polymerization methods include a batch reaction in which an ethylenically unsaturated monomer, a surfactant, and water are all charged into a reaction vessel and reacted, and a dropping reaction in which the monomer is gradually dropped into a reaction vessel and reacted. Among these, a dropping reaction is preferred from the viewpoint of easy control of heat generation in the polymerization reaction. In addition, in the dropping reaction, in order to further improve polymerization stability, it is preferable to mix and stir the monomer, water, and surfactant to form an emulsified pre-emulsion and then dropwise add the pre-emulsion.

[0048] When obtained by emulsion polymerization, the resin fine particles (A) preferably have an average particle size of 50 to 400 nm, more preferably 150 to 300 nm, from the viewpoint of being applied in a stable state and exhibiting excellent adhesiveness, saltwater resistance, and oil resistance. The average particle size was measured using dynamic light scattering. 50 This is the average particle size. For example, the measurement method involves diluting the aqueous dispersion of polymer particles 500 times with water to prepare a diluted solution, and measuring the particle size using approximately 5 mL of the diluted solution with Nanotrac (manufactured by Nikkiso Co., Ltd.).

[0049] <Optional ingredients> The patch for indirect skin application of the present invention may contain additives such as extender pigments, thickeners, moisturizers, preservatives, solvents, antifoaming agents, and wetting agents as optional components, as long as the problem can be solved. Examples of extender pigments include talc, silica, calcium carbonate, barium sulfate, titanium oxide, and diatomaceous earth. Examples of thickeners include alkali swelling thickeners, associative polyurethanes, carboxyvinyl polymers, thickening polysaccharides, and clay minerals. Examples of moisturizing agents include sorbitol, xylitol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, glycerin, diglycerin, polyethylene glycol, hyaluronic acid, chondroitin sulfate, pyrrolidone carboxylate, and DL-pyrrolidone carboxylate. Examples of the solvent include ethyl alcohol, isopropyl alcohol, and n-butyl alcohol. Examples of preservatives include methyl parahydroxybenzoate, ethyl parahydroxybenzoate, propyl parahydroxybenzoate, butyl parahydroxybenzoate, benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, phenoxyethanol, 4-hydroxyacetophenone, dehydroacetic acid, caprylyl glycol, and pentylene glycol. Examples of the antifoaming agent include silicone-based antifoaming agents and mineral oil-based antifoaming agents. Examples of the wetting agent include the surfactants exemplified in the synthesis of the resin fine particles (A).

[0050] ≪Adhesive layer≫ The adhesive layer is formed by volatilization of volatile components such as water and solvents from the patch for indirect skin wear of the present invention. The patch for direct skin contact can be applied directly to the skin and allowed to dry naturally to form an adhesive layer, or the patch for direct skin contact can be applied to a peelable substrate first, dried to form an adhesive layer, and a sheet for skin contact can be produced, which can then be transferred onto the skin for use. Any substrate can be used as the release substrate as long as no adhesive layer remains on the substrate during transfer. Examples of the release substrate include silicone-coated polyethylene terephthalate, release polyethylene terephthalate, and release polyolefin.

[0051] The amount of the adhesive layer applied per unit area is not particularly limited, but from the viewpoint of exhibiting excellent adhesiveness, it is preferably 5 to 50 g / m in terms of solid content. 2 The range is preferably 10 to 40 g / m 2 is.

[0052] The method of attaching the skin with a skin patch can be any method, such as applying the skin patch to one side of the skin, attaching the other side of the skin and then drying, applying the skin patch to one side of the skin, drying it once and then attaching the other side of the skin, or attaching the above-mentioned skin patch sheet to one side of the skin, transferring an adhesive layer onto the skin, and then attaching the other side of the skin. When applying the skin patch directly to the skin, the drying temperature is preferably in the range of 25 to 50°C to minimize damage to the skin.

[0053] The indirect skin patch and skin adhesive sheet of the present invention can be used in a variety of applications for the purpose of bonding skin to skin, such as in medical, cosmetic, and special makeup applications. [Example]

[0054] The present invention will be described in more detail below with reference to examples, but the following examples do not limit the scope of the invention in any way. In the examples, "parts" means "parts by mass," "%" means "% by mass," and the values ​​in the tables are solid content masses, and blank spaces indicate empty spaces. The octanol / water partition coefficient (Log Kow) of the ethylenically unsaturated monomer, the acid value of the resin fine particles (A), the glass transition temperature (Tg), and the average particle size are measured as follows.

[0055] <Octanol / water partition coefficient (Log Kow)> The octanol / water partition coefficient (Log Kow) of the ethylenically unsaturated monomer at 25°C was calculated using the YMB method (physical property prediction function) of the software HSPiP (Ver. 5.02.5) by converting the structural formula of the ethylenically unsaturated monomer into Smiles notation and entering it. (Formula 1) Log Kow = Log (concentration of compound X in the octanol phase / concentration of compound X in the aqueous phase)

[0056] <Acid value> The acid value of resin microparticles (A) is the number of milligrams of potassium hydroxide required to neutralize the acidic components contained in 1 g of dried resin. It was calculated by potentiometric titration using a potassium hydroxide-ethanol solution on an automatic titrator (HIRANUMA "COM" model) according to the method described in JIS K2501.

[0057] <Glass transition temperature> The glass transition temperature of the resin microparticles (A) was measured using a DSC (differential scanning calorimeter, manufactured by TA Instruments). Specifically, an aluminum pan containing approximately 3 mg of precisely weighed dried resin and an empty aluminum pan serving as a reference were set in a DSC measurement holder, and measurement was performed at a temperature increase rate of 10°C / min. The temperature at the intersection of the baseline on the low-temperature side of the endothermic phenomenon and the tangent to the inflection point in the DSC curve was taken as the glass transition temperature (Tg).

[0058] <Average particle size> The average particle size of the resin microparticles (A) was measured by diluting the aqueous dispersion of the resin microparticles (A) 1000 times with water and measuring approximately 5 ml of the diluted solution using a dynamic light scattering measurement method (measuring device manufactured by Nanotrac UPA Co., Ltd., Microtrac Bell Co., Ltd.) The peak of the obtained volume particle size distribution data (histogram) was taken as the average particle size.

[0059] <Manufacturing of indirect skin patches> [Example 1] 19.0 parts of ion-exchanged water was charged into a flask (reaction tank) equipped with a reflux condenser, a dropping funnel, a stirrer, a thermometer, a nitrogen gas inlet, and a raw material inlet, and the liquid temperature was heated to 80°C while stirring under nitrogen gas introduction. As the ethylenically unsaturated monomer (a-1), 6.0 parts of methoxyethyl acrylate, 25.0 parts of methyl methacrylate, as the ethylenically unsaturated monomer (a-2), 49.0 parts of n-butyl acrylate, as the other ethylenically unsaturated monomer (a-3), 10.0 parts of 2-ethylhexyl acrylate, 7.0 parts of n-lauryl acrylate, 1.0 parts of 2-hydroxyethyl acrylate, 1.5 parts of methacrylic acid, 0.5 parts of acrylic acid, 11.9 parts of a 10% aqueous solution of Emal 0 (Kao Corporation, sodium lauryl sulfate), 0.04 parts of 2-ethylhexyl thioglycolate as a chain transfer agent, and 19.6 parts of ion-exchanged water were stirred and mixed to prepare a pre-emulsion (an emulsion of an ethylenically unsaturated monomer), which was then charged into a dropping funnel (dropping tank). A flask was charged with 0.12 parts of a 10% aqueous solution of Emal 0 and 6.6 parts of a 5.0% pre-emulsion. Then, 10.0 parts of a 5% aqueous solution of potassium persulfate was added to the flask as a polymerization initiator, and the remaining pre-emulsion was continuously added dropwise from the dropping funnel over 180 minutes. Emulsion polymerization was carried out while maintaining the temperature at 80°C. After the dropwise addition, stirring was continued for 5 hours while maintaining the temperature at 80°C, yielding an aqueous dispersion of resin microparticles (A). After the reaction, 25% ammonia water was added to neutralize the resin acid value to 100%, and then further water was added to adjust the solids content of the aqueous dispersion of resin microparticles (A) to 55.0%. Then, 0.5 parts of phenoxyethanol was added as an additive component to obtain a patch for indirect skin contact.

[0060] [Examples 2 to 24, Comparative Examples 1 to 10] Patches for indirect skin application were obtained in the same manner as in Example 1, except that the formulations and amounts (parts by mass) shown in Tables 1 to 3 were used. In Examples 9, 20, and 21, and Comparative Example 8, the amount of 10% aqueous solution charged into the flask was changed to 0.08, 1.33, 0.01, and 0.08 parts, respectively, to synthesize resin microparticles (A). In Example 11 and Comparative Example 10, the surfactant was changed from Emal 0 to Aqualon KH-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polyoxyethylene-1-(allyloxymethyl) alkyl ether ammonium sulfate), and the amount of 10% aqueous solution of KH-10 charged into the flask was changed to 0.05 and 0.03 parts, respectively, and the amount of 10% aqueous solution of KH-10 charged into the dropping tank was changed to 12.3 and 12.1 parts, respectively.

[0061] [Surface tension γ] The surface tension γ of the above prepared indirect skin patch was measured at 25°C by the plate method (Wilhelmy method) using a surface tensiometer (automatic surface tensiometer DY-300) manufactured by Kyowa Kaimen Co., Ltd.

[0062] <Elution rate> The obtained indirect skin patch was poured into a silicone container frame and dried at 40°C for 96 hours (48 hours per side). The test piece of the obtained resin coating was wrapped in a metal mesh and immersed in ethyl acetate at 50°C for 72 hours, and the amount eluted from the resin coating was measured. The amount eluted was calculated using the following formula. Dissolution rate (%) = (mass of coating film before immersion - mass of coating film after immersion) / mass of coating film after immersion × 100

[0063] <Preparation of skin patch sheet> [Example 25] The indirect skin patch of Example 22 was applied with a bar coater at a dry equivalent of 30 g / m 2 After coating the sheet on a release PET substrate so that the film was uniform, it was dried in an oven at 100°C for 5 minutes to prepare a sheet for application to the skin.

[0064] <Evaluation of indirect skin patches> The adhesive properties, saltwater resistance, oil resistance, resistance to a mixture of saltwater and oil, and skin irritation were evaluated using the above-prepared transdermal patches and skin adhesive sheets. The results are shown in Tables 1 to 3.

[0065] <Adhesion evaluation> The resulting indirect skin patch was applied to the Supprale artificial skin at a dry equivalent of 30 g / m 2 After coating, the coating was dried at 25°C for 5 minutes and test pieces measuring 10mm long and 20mm wide were prepared. Two test pieces were prepared for each test, the coated surfaces of which were bonded together and pressed together at 0.5MPa, and then left to cure at 23°C and 50% humidity. After curing, one end of the test piece was pulled in the 180° direction, and the peel strength was measured using a tensile tester (Shimadzu Corporation, "AGS-X") (peel speed: 300 mm / min, unit: N / 20 mm width). The adhesive sheet of Example 25 was prepared by transferring the adhesive layer onto Supprale artificial skin to prepare a coated product. [Evaluation criteria] S: Peel strength is 10N / 20mm or more. Extremely good. A: Peel strength is 5N / 20mm or more and less than 10N / 20mm. Good. B: Peel strength is 3N / 20mm or more and less than 5N / 20mm. Practical use is possible. C: Peel strength is less than 3N / 20mm. Problems in practical use.

[0066] <Saltwater resistance evaluation> 300 parts of a 0.4% by mass aqueous solution of sodium chloride was prepared in a 500 ml glass bottle to have the same salt concentration as sweat, and then the test pieces prepared in the same manner as in the adhesion evaluation and bonded together were immersed in the solution at 37°C for 24 hours. After immersion, the salt water adhering to the test pieces was lightly wiped off, and the peel strength was measured in the same manner as in the adhesion evaluation. The rate of change in peel strength before and after immersion was calculated from the obtained peel strength. Change rate [%] = (peel strength before immersion in salt water - peel strength after immersion in salt water) / peel strength before immersion in salt water × 100 [Evaluation criteria] S: Peel strength change rate is less than 1%, extremely good. A: The change in peel strength is 1% or more and less than 5%. Good. B: The change in peel strength is 5% or more and less than 10%. Practical use is possible. C: The rate of change in peel strength is 10% or more. There is a problem in practical use.

[0067] <Oil resistance evaluation> 300 ml of jojoba oil, a component similar to sebum, was placed in a 500 ml glass bottle, and the bonded test pieces prepared above were immersed in the oil at 37°C for 24 hours. After immersion, the oil adhering to the test pieces was lightly wiped off, and the peel strength was measured in the same manner as above. The rate of change in peel strength before and after immersion was calculated from the obtained peel strength. Change rate [%] = (peel strength before oil immersion - peel strength after oil immersion) / peel strength before oil immersion × 100 [Evaluation criteria] S: Peel strength change rate is less than 1%, extremely good. A: The change in peel strength is 1% or more and less than 5%. Good. B: The change in peel strength is 5% or more and less than 10%. Practical use is possible. C: The rate of change in peel strength is 10% or more. There is a problem in practical use.

[0068] <Resistant to saltwater and oil mixtures> A 500 ml glass bottle was filled with 150 parts of 0.4% sodium chloride aqueous solution and 150 parts of jojoba oil, and the bonded test piece prepared above was immersed in the solution. The bottle was then capped and shaken in a shaker at 37°C for 24 hours. After shaking, the test piece was taken out, the salt water and oil adhering to the test piece were lightly wiped off, and the peel strength was measured in the same manner as above. The rate of change in peel strength before and after immersion was calculated from the obtained peel strength. Change rate [%] = (peel strength before immersion in mixed liquid - peel strength after immersion in mixed liquid) / peel strength before immersion in mixed liquid × 100 [Evaluation criteria] S: Peel strength change rate is less than 1%, extremely good. A: The change in peel strength is 1% or more and less than 5%. Good. B: The change in peel strength is 5% or more and less than 10%. Practical use is possible. C: The rate of change in peel strength is 10% or more. There is a problem in practical use.

[0069] <Skin irritation> The above-mentioned indirect skin patch was applied to the inside of the arm of 10 subjects, and the subjects were observed for 24 hours to evaluate whether any abnormalities such as itching or rash occurred. The adhesive sheet of Example 23 was applied to the skin to transfer the adhesive layer. [Evaluation criteria] A: No subjects experienced any abnormalities. Good. B: One subject experienced abnormalities. Practical use possible. C: Two or more subjects experienced abnormalities. Practical problems.

[0070] The abbreviations in the table are as follows: Emulgen TW-O320: Polyoxyethylene sorbitan trioleate manufactured by Kao Corporation Emulgen 409P: Polyoxyethylene oleyl ether manufactured by Kao Corporation

[0071] [Table 1]

[0072] [Table 2]

[0073] [Table 3]

[0074] As can be seen from Tables 1 to 3, the indirect skin patches of Examples 1 to 24 and the indirect skin sheet of Example 25 were very excellent in adhesiveness, saltwater resistance, and oil resistance. Furthermore, they were also very durable even under harsh conditions where saltwater and oil coexisted, and caused very little skin irritation. On the other hand, the indirect skin patches of Comparative Examples 1 to 10 were significantly inferior in one of the various performances and did not meet practical standards.

Claims

1. Contains resin fine particles (A) and an aqueous medium, The resin fine particles (A) have a glass transition temperature of −60 to −10° C. and an acid value of 3.0 to 40.0 mgKOH / g, The resin fine particles (A) are a polymer of an ethylenically unsaturated monomer mixture containing the following ethylenically unsaturated monomer (a-1) and the following ethylenically unsaturated monomer (a-2), the content of the ethylenically unsaturated monomer (a-1) is 2.0 to 40.0 mass% and the content of the ethylenically unsaturated monomer (a-2) is 20.0 to 97.5 mass% in 100 mass% of the ethylenically unsaturated monomer mixture; A patch for indirect skin application, having a surface tension of 25.0 to 50.0 mN / m at 25°C. (a-1): A nonionic ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 0.4 or more and less than 2.

0. (a-2): An ethylenically unsaturated monomer having a logarithm of the octanol / water partition coefficient (Log Kow) at 25°C of 2.0 or more and less than 2.5

2. The patch for indirect skin wear according to claim 1, wherein the total content of the ethylenically unsaturated monomer (a-1) and the ethylenically unsaturated monomer (a-2) is 40.0 to 99.5% by mass in 100% by mass of the ethylenically unsaturated monomer mixture.

3. The adhesive layer formed from the patch for indirect skin application is 3. The patch for indirect skin application according to claim 1, which has an elution rate of 50.0 to 100.0% by mass when immersed in ethyl acetate at 50°C for 24 hours.

4. The patch for indirect skin wear according to any one of claims 1 to 3, wherein the ethylenically unsaturated monomer (a-1) comprises at least one ethylenically unsaturated monomer selected from the group consisting of methoxyethyl acrylate, methyl acrylate, and methyl methacrylate.

5. The patch for indirect skin application according to any one of claims 1 to 4, wherein the ethylenically unsaturated monomer (a-2) includes at least one of n-butyl acrylate and phenoxyethyl acrylate.

6. An adhesive layer formed from the patch for indirect skin application according to any one of claims 1 to 5.

7. A patch sheet for indirect skin wear, comprising a releasable substrate and the adhesive layer according to claim 6.

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