Facial patch

Abstract

To provide a facial patch having suitable adhesion to a facial skin, which achieves a good face observation result and is designed to sufficiently reduce an amount of corneocyte exfoliation.SOLUTION: A facial patch includes a substrate, an adhesive layer, and a release layer in this order. The adhesive layer contains an urethane-based adhesive.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a facial patch, and more particularly to a facial patch that is used by being attached to the skin of the face. [Background technology]

[0002] A patch to be applied to the skin has a layer structure comprising a support and an adhesive layer provided on at least one side of the support. In addition, a release layer is often provided to protect the surface of the adhesive layer, and in cases where the support is extremely thin, the support often has a layer structure in which a carrier layer such as a carrier film is provided on the support.

[0003] Since patches are applied to the skin and then peeled off, and in many cases a new patch is then applied, they are required to remain on the skin for a desired period of time, to be easily and cleanly peeled off, and not to cause strong irritation to the skin. Furthermore, when patches are applied to areas of the skin that are exposed in daily life, such as the face, they may also be required to be inconspicuous where they are applied.

[0004] That is, patches are required to have an appropriate adhesive strength. If the adhesive strength is too weak, the patch will easily peel off from the skin surface or will not adhere closely to the skin surface, which may have minute irregularities such as skin grooves. If the adhesive strength is too strong, it may cause a rash or be difficult to remove after use.

[0005] The face is an area where more sebum is secreted than the arms, shoulders, etc. When a patch is applied to the face, where a lot of sebum is secreted, the adhesive in the adhesive layer absorbs the sebum secreted from the facial skin, which reduces the cohesive strength of the adhesive and may make the patch more likely to peel off. Therefore, it has been thought that it is necessary to make the adhesive layer sufficiently thick so that the patch will not peel off even if it absorbs a large amount of sebum.

[0006] The so-called T-zone area of ​​the face, such as the forehead and nose, is an area where sebum is secreted in particularly large amounts and is prone to acne. It is important to keep areas with acne as clean as possible. Applying foundation or other products directly to the skin after washing the face may exacerbate redness or cause suppuration in the areas with acne. If the adhesive layer is made thinner, it may be difficult to obtain adequate adhesive strength.

[0007] Therefore, there has been a demand for a facial patch that can be applied to the skin of the face, where sebum is secreted in large amounts, for a long period of time, that leaves little adhesive residue, and that causes little skin irritation, as well as a patch that is not very noticeable when applied.

[0008] For example, Patent Document 1 discloses a facial patch that can be applied to the facial skin where sebum is secreted in large amounts for a long period of time, and that leaves little adhesive residue and causes little skin irritation. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 5285822 Summary of the Invention [Problem to be solved by the invention]

[0010] However, a facial patch that has adequate adhesive strength to facial skin, produces good skin observation results, and sufficiently reduces the amount of keratin peeling has not yet been obtained, and there is a strong demand for its development.

[0011] In view of the above problems, the present invention aims to provide a facial patch that has appropriate adhesive strength to facial skin, provides good skin observation results, and sufficiently reduces the amount of keratin peeling. [Means for solving the problem]

[0012] As a result of intensive research into solving the above-mentioned problems, the inventors have discovered that in a facial patch comprising a support, an adhesive layer, and a release layer, in that order, when the adhesive layer contains a urethane-based adhesive, a facial patch can be obtained which has appropriate adhesion to facial skin, gives good skin observation results, and sufficiently reduces the amount of keratin peeling, thereby completing the present invention. That is, the present invention is as follows. [1] A facial patch comprising a support, an adhesive layer, and a release layer in this order, the adhesive layer containing a urethane-based adhesive. [2] The facial patch according to the above [1], wherein the adhesive strength of the adhesive layer to facial skin is 0.5 to 2.8 N / 15 mm. [3] The facial patch according to [1] or [2] above, wherein the adhesive layer has an average content of ethylene oxide-based structural units of 60% by mass or less. [4] The facial patch according to any one of [1] to [3] above, wherein the urethane-based adhesive is a cured product of an adhesive composition containing a hydroxyl group-terminated urethane prepolymer and a polyisocyanate compound. [5] The facial patch according to [4] above, wherein the pressure-sensitive adhesive composition has an average content of ethylene oxide-based structural units of 60 mass % or less. [6] The facial patch according to [4] or [5] above, wherein the hydroxyl-terminated urethane prepolymer is a reaction product of an oxyalkylene polymer and a diisocyanate compound in the presence of a tin-free catalyst. [7] The facial patch according to [6] above, wherein the tin-free catalyst contains at least one of zinc and bismuth. [8] The facial patch according to [6] or [7] above, wherein the oxyalkylene polymer has an average content of ethylene oxide-based structural units of 60% by mass or less. [9] The facial patch according to any one of the above [6] to [8], wherein the oxyalkylene polymer has an average number of hydroxyl groups per molecule of 1.5 to 3.0.

[10] The facial patch according to any one of [6] to [9] above, wherein the oxyalkylene polymer comprises an oxyalkylene polymer A having an average number of hydroxyl groups per molecule of 2.0 or more, and an oxyalkylene polymer B having an average number of hydroxyl groups per molecule of 1.

[11] The facial patch described in

[10] above, wherein the oxyalkylene polymer A includes an oxyalkylene polymer A1 having 3 hydroxyl groups per molecule and an oxyalkylene polymer A2 having 2 hydroxyl groups per molecule. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a facial patch that has an appropriate adhesive strength to facial skin, gives good skin observation results, and sufficiently reduces the amount of keratin peeling. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described in detail below. In this specification, the preferred definitions can be adopted arbitrarily, and it can be said that a combination of preferred definitions is more preferred. In this specification, the expression "XX to YY" means "XX or more and YY or less." In this specification, for preferred numerical ranges (e.g., ranges of content, etc.), the lower and upper limits described in stages can be independently combined. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60." Furthermore, in the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. In this specification, "facial skin" may also be referred to simply as "skin." The number average molecular weight (Mn) and weight average molecular weight (Mw) are polystyrene-equivalent molecular weights determined by gel permeation chromatography (GPC) based on a calibration curve prepared using standard polystyrene samples. The isocyanate index is the equivalent ratio ([isocyanate group] / [active hydrogen-containing group]) of the isocyanate groups to be reacted to the active hydrogen-containing groups (e.g., hydroxyl groups), and is expressed as a percentage. For example, an isocyanate index of 85 indicates that the equivalent ratio of the isocyanate groups to the active hydrogen-containing groups (e.g., hydroxyl groups) is 85%. In this specification, the term "solid content" refers to the non-volatile content excluding volatile substances such as solvents, and indicates components that remain without volatilization when the PSA composition is dried, including those that are liquid, syrup-like, or wax-like at room temperature. The total solid content can also be calculated from the charge amount.

[0015] [Facial patches] A facial patch in an embodiment of the present invention (hereinafter sometimes simply referred to as "the present embodiment") comprises a support, an adhesive layer, and a release layer in this order.

[0016] The thickness of the facial patch is not particularly limited, but is preferably 5 to 1000 μm, more preferably 10 to 500 μm, and particularly preferably 15 to 100 μm. If the thickness of the facial patch is within the above range, it can be applied to the facial skin for a long period of time with little discomfort when applied.

[0017] In one embodiment, the facial patch of the present invention can use a urethane-based adhesive obtained by curing an adhesive composition described below in the adhesive layer.

[0018] (Support) The backing is preferably made of a material that allows the facial patch to conform well to the facial skin and is unlikely to break when the facial patch is in use. The material of the support is not particularly limited, and examples thereof include resin film, cloth, paper, etc. These may be used alone or in combination of two or more. They may also be composite materials formed by lamination or the like.

[0019] The material of the resin film is not particularly limited, and examples thereof include polyurethane, polyamide, acrylic resin, polyolefin such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyester, etc. These may be used alone or in combination of two or more. Among these, polyurethane, polyamide, and polyethylene are preferred, and thermoplastic polyurethane is more preferred, from the viewpoint of good moisture permeability when applied to the skin. The form of the fabric is not particularly limited, and examples thereof include woven fabric, nonwoven fabric, knitted fabric, net, etc. These may be used alone or in combination of two or more. The material of the fabric is not particularly limited, and examples thereof include the resins used in the resin film described above, and natural fibers such as cotton, silk, wool, etc. These may be used alone or in combination of two or more.

[0020] The support may or may not include an auxiliary layer. Examples of the auxiliary layer are not particularly limited, and include a colored layer, an undercoat layer, an antistatic layer, and the like provided on the surface of the support.

[0021] The surface of the support may be subjected to a surface treatment such as physical treatments such as corona discharge treatment, plasma treatment, sand matting treatment, ozone exposure treatment, flame exposure treatment, high-voltage shock exposure treatment, ionizing radiation treatment, sandblasting treatment, etc.; chemical treatments such as chromic acid treatment; or easy-adhesion treatment using a coating agent (primer), etc., for the purpose of improving adhesion and retention with the pressure-sensitive adhesive layer. Surface treatments for improving adhesion are preferably applied to the entire surface of the support.

[0022] Furthermore, in order to improve the feel, smoothness, appearance, etc. of the facial patch when it is applied to the skin surface of the face, it may be preferable to form minute irregularities on the back surface of the support that constitutes the facial patch (meaning "the surface of the support opposite the adhesive layer side"). In other words, the surface of the support opposite the adhesive layer side can be matte-finished to form a facial patch. The matte finish can increase the dynamic friction coefficient of the support surface to 1.0 or more.

[0023] The thickness of the support is not particularly limited, but is preferably 5 to 200 μm, more preferably 8 to 150 μm, and particularly preferably 10 to 100 μm, from the viewpoint of ensuring conformability to the skin shape and preventing the support from breaking when the facial patch is used. When the thickness of the support is equal to or greater than the lower limit, the strength of the support is sufficient, preventing the support from tearing when the facial patch is applied to the face or peeled off from the face, and preventing difficulties in manufacturing the support. When the thickness of the support is equal to or less than the upper limit, the facial patch is less likely to adhere to the skin surface of the face, which has fine irregularities such as skin grooves, making the applied state more noticeable, increasing the sense of discomfort, and reducing problems such as increased pain when peeling off. The thickness of the support is measured using a dial thickness gauge. The same method is used to measure the thickness of the other layers of the facial patch.

[0024] The composition constituting the support may contain, if desired, organic or inorganic additives such as colorants such as pigments and dyes; stabilizers; ultraviolet absorbers; lubricants; and the like. The content of the additive is not particularly limited, but is preferably 0.001 to 30 parts by mass, more preferably 0.01 to 25 parts by mass, and particularly preferably 0.1 to 20 parts by mass, relative to 100 parts by mass of the composition constituting the support.

[0025] (Adhesive layer) The adhesive forming the adhesive layer is not particularly limited as long as it contains a urethane-based adhesive, and may contain an adhesive other than a urethane-based adhesive. The content of the urethane-based adhesive in the adhesive forming the adhesive layer is not particularly limited, but is preferably 50% by mass or more, more preferably 70% by mass or more, particularly preferably 90% by mass or more, and most preferably 100% by mass. The adhesives other than the urethane adhesives are not particularly limited, and examples thereof include acrylic adhesives, silicone adhesives, rubber adhesives (natural rubber, synthetic rubber, mixtures thereof, etc.), polyester adhesives, polyether adhesives, polyamide adhesives, fluorine adhesives, etc. These may be used alone or in combination of two or more.

[0026] The pressure-sensitive adhesive layer may be a single layer or multiple layers. When the pressure-sensitive adhesive layer is multiple layers, the multiple pressure-sensitive adhesive layers may be the same pressure-sensitive adhesive layer, or may be pressure-sensitive adhesive layers different in composition, thickness, physical properties, etc. The pressure-sensitive adhesive layer may be formed partially on one side (first side) of the support, or may be formed over the entire first side of the support.

[0027] The thickness of the adhesive layer is not particularly limited, but from the viewpoint of ensuring good adhesive strength to the skin, it is preferably 5 to 100 μm, more preferably 10 to 80 μm, and particularly preferably 15 to 50 μm.

[0028] The average content of ethylene oxide-based structural units (hereinafter abbreviated as "EO units") in the adhesive layer is not particularly limited, but from the viewpoint of obtaining an adhesive that is gentle on the skin and has good adhesive strength to the skin, it is preferably 60% by mass or less, more preferably 8 to 55% by mass, even more preferably 10 to 50% by mass, even more preferably 12 to 40% by mass, and particularly preferably 15 to 25% by mass. The average content of EO units in the pressure-sensitive adhesive layer is derived from the EO units constituting the oxyalkylene chain of the oxyalkylene polymer in the hydroxyl-terminated urethane prepolymer, and 13 It can be determined by analyzing the monomer composition of the oxyalkylene chain in the pressure-sensitive adhesive layer using C-NMR (nuclear magnetic resonance) measurement.

[0029] The adhesive strength of the adhesive layer to the facial skin is not particularly limited, but from the viewpoint of being gentle to the skin and having good adhesive strength to the skin, it is preferably 0.5 to 2.8 N / 15 mm, more preferably 1.0 to 2.5 N / 15 mm, and particularly preferably 1.5 to 2.2 N / 15 mm.

[0030] The amount of keratin peeled after the adhesive layer is attached to the facial skin for one day ("amount of keratin peeled after one day of attachment") is not particularly limited, but is preferably 0.060 mg / cm 2 or less, more preferably 0.040 mg / cm 2 or less, more preferably 0.030 mg / cm 2 or less, more preferably 0.020 mg / cm 2 Below 0.015 mg / cm, particularly preferably 2 If the amount of keratin exfoliation after one day of application is equal to or less than the upper limit, the condition of the skin after the facial patch is removed from the skin will be good, and the facial patch is excellent in gentleness to the skin. The "amount of keratin peeled after one day of application" here is measured in the same manner as in the Examples.

[0031] The moisture permeability of the adhesive layer is preferably 1500 g / (m 2 ) from the viewpoint of providing a low load to the facial skin and good adhesive strength. 2 ·day) or more, more preferably 3000g / (m 2 ·day) or more, more preferably 4000g / (m 2 ·day) or more. There is no particular upper limit to the moisture permeability. The moisture permeability in the present invention is a value measured in an atmosphere of 40° C. and 90% RH when the adhesive layer has a thickness of 25 μm. Specifically, it is measured by the method described in the examples.

[0032] The toxicity of the adhesive layer is not particularly limited, but from the viewpoint of application to the skin, it is preferable that the adhesive layer is low in toxicity, and the colony formation rate in a cytotoxicity test using the colony formation method specified in ISO 10993-5:2009 is preferably 50% or more, more preferably 70% or more.

[0033] ((Urethane adhesive)) As the urethane-based adhesive, a urethane-based adhesive obtained by curing an adhesive composition described below is preferred from the viewpoint of gentleness to the skin. The urethane-based adhesive obtained by curing the adhesive composition described below has a good adhesive strength of the adhesive layer to the skin, does not leave adhesive residue, and can be suitably applied to the skin.

[0034] <Adhesive composition> The pressure-sensitive adhesive composition contains, for example, a hydroxyl group-terminated urethane prepolymer and a polyisocyanate compound, and optionally other components.

[0035] The average content of ethylene oxide-based structural units (hereinafter abbreviated as "EO units") in the pressure-sensitive adhesive composition is not particularly limited, but from the viewpoint of obtaining a pressure-sensitive adhesive that is gentle on the skin and has good adhesion to the skin, it is preferably 60% by mass or less, more preferably 8 to 55% by mass, even more preferably 10 to 50% by mass, even more preferably 12 to 40% by mass, and particularly preferably 15 to 25% by mass. The average content of EO units in the pressure-sensitive adhesive composition is derived from the EO units constituting the oxyalkylene chain of the oxyalkylene polymer in the hydroxyl-terminated urethane prepolymer. 13 It can be determined by analyzing the monomer composition of the oxyalkylene chain in the pressure-sensitive adhesive composition by C-NMR (nuclear magnetic resonance) measurement.

[0036] <<Hydroxyl-terminated urethane prepolymer>> The hydroxyl-terminated urethane prepolymer is a reaction product of an oxyalkylene polymer and a diisocyanate compound, preferably a reaction product of an oxyalkylene polymer and a diisocyanate compound in the presence of a tin-free catalyst.

[0037] The EO unit content in the hydroxyl group-terminated urethane prepolymer is not particularly limited, but is preferably 60% by mass or less, more preferably 5 to 55% by mass, even more preferably 10 to 50% by mass, still more preferably 12 to 40% by mass, and particularly preferably 15 to 25% by mass. When the EO unit content in the hydroxyl group-terminated urethane prepolymer is within the above range, it is easy to obtain a pressure-sensitive adhesive that is gentle on the skin and has good adhesive strength to the skin. The EO unit content in the hydroxyl-terminated urethane prepolymer was the weighted average of the EO unit content in each component of the raw material. Note that the EO unit content in the hydroxyl-terminated urethane prepolymer was also calculated as follows, similar to the EO unit content in the PSA composition: 13 It can also be determined by C-NMR measurement.

[0038] -Oxyalkylene polymer- The average content of EO units in the oxyalkylene polymer is not particularly limited, but is preferably 60% by mass or less, more preferably 8 to 55% by mass, even more preferably 10 to 50% by mass, still more preferably 12 to 40% by mass, and particularly preferably 15 to 25% by mass. When multiple oxyalkylene polymers are used in the synthesis of the hydroxyl-terminated urethane prepolymer, the average content of EO units in the oxyalkylene polymer refers to the weighted average value of the EO unit contents in each oxyalkylene polymer based on the blending amounts of these multiple oxyalkylene polymers. The EO unit content in each oxyalkylene polymer is a value calculated based on the blending amount of EO in the raw material in the synthesis of the oxyalkylene polymer. Note that the EO unit content in the oxyalkylene polymer, like the EO unit content in the pressure-sensitive adhesive composition, is also 13 It can also be determined by C-NMR measurement. When the average content of EO units in the oxyalkylene polymer is within the above range, it is easy to obtain a pressure-sensitive adhesive that is gentle on the skin and has good adhesive strength to the skin.

[0039] The average number of hydroxyl groups per molecule of the oxyalkylene polymer is not particularly limited, but from the viewpoint of obtaining a pressure-sensitive adhesive that is gentle on the skin and has good adhesive strength to the skin, it is preferably 1.5 to 3.0, more preferably 1.7 to 2.8, and particularly preferably 1.9 to 2.6. The average number of hydroxyl groups per molecule of the oxyalkylene polymer refers to the weighted average value of the numbers of hydroxyl groups per molecule of the oxyalkylene polymer based on the blend amounts of multiple oxyalkylene polymers used in the synthesis of the hydroxyl-terminated urethane prepolymer. The oxyalkylene polymer may be one kind of oxyalkylene polymer or two or more kinds of oxyalkylene polymers.

[0040] The oxyalkylene polymer preferably includes an oxyalkylene polymer A (hereinafter sometimes simply referred to as "polymer A") having an average number of hydroxyl groups per molecule of 2.0 or more, and an oxyalkylene polymer B (hereinafter sometimes simply referred to as "polymer B") having an average number of hydroxyl groups per molecule of 1. The hydroxyl groups of polymer A and polymer B react with the isocyanate groups of the diisocyanate compound to form urethane bonds, thereby producing a hydroxyl-terminated urethane prepolymer. It is preferable that the unreacted hydroxyl groups of the hydroxyl groups of polymer A and polymer B are terminal hydroxyl groups of the molecular chain of the hydroxyl-terminated urethane prepolymer.

[0041] The total content of polymer A and polymer B in the oxyalkylene polymer is not particularly limited, but is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 100% by mass. The content ratio of polymer A and polymer B in the oxyalkylene polymer is not particularly limited, but from the viewpoint of obtaining an adhesive agent having good adhesive strength to the skin, the mass ratio is preferably 10 / 90 to 95 / 5, more preferably 30 / 70 to 90 / 10, even more preferably 50 / 50 to 85 / 15, and particularly preferably 60 / 40 to 85 / 15.

[0042] --Oxyalkylene polymer A-- The polymer A has two or more, preferably two to six, hydroxyl groups per molecule. Polymer A may be one type of oxyalkylene polymer or two or more types of oxyalkylene polymers. When polymer A is made of two or more types of oxyalkylene polymers, the adhesive strength of the pressure-sensitive adhesive can be easily adjusted. When polymer A is composed of two or more kinds of oxyalkylene polymers, the average number of hydroxyl groups per molecule of polymer A is not particularly limited, but is preferably 2.1 to 3.0, more preferably 2.2 to 2.9, and particularly preferably 2.3 to 2.8. When the average number of hydroxyl groups of the polymer A is within the above range, a pressure-sensitive adhesive that is less likely to leave adhesive residue on the skin can be obtained. The average number of hydroxyl groups per molecule of polymer A can be calculated from the measured values ​​of the hydroxyl value and Mn of polymer A by the formula: hydroxyl value×Mn / 56100. Commercially available products can also be used as the polymer A. Examples of commercially available products of the polymer A include "Preminol (registered trademark; hereinafter, abbreviated) S 4013F," "Preminol S 4318F," "Preminol S 3011," "Preminol 5001F," "Preminol 7001K," "Preminol 7012," "Preminol S 4011," "Preminol S 4015," "Preminol S 3025," and "Preminol S 6420" (all manufactured by AGC Inc.); "ACCLAIM (registered trademark; hereinafter, abbreviated) 4200," "ACCLAIM 8200," "ACCLAIM 2220N," "ACCLAIM 3300N," "ACCLAIM 4220N," "ACCLAIM 6300," "Acclaim 2200," and "ACCLAIM 6320N" (all manufactured by Covestro).

[0043] When polymer A is composed of two or more types of oxyalkylene polymers, examples of polymer A include one containing an oxyalkylene polymer A1 having three hydroxyl groups per molecule (hereinafter sometimes simply referred to as "polymer A1") and an oxyalkylene polymer A2 having two hydroxyl groups per molecule (hereinafter sometimes simply referred to as "polymer A2"). Polymer A1 may be one type alone or two or more types. Similarly, polymer A2 may be one type alone or two or more types. The polymer A may contain an oxyalkylene polymer having four or more hydroxyl groups per molecule. In addition, when polymer A consists of polymer A1 and polymer A2, the average number of hydroxyl groups of polymer A can be considered to be the weighted average value based on the composition ratio (blending amount) of polymer A1 and polymer A2, where the number of hydroxyl groups per molecule of polymer A1 is 3 and the number of hydroxyl groups per molecule of polymer A2 is 2.

[0044] The total amount of polymer A1 and polymer A2 in 100 parts by mass of polymer A is not particularly limited, but from the viewpoint of ease of adjusting the adhesive strength of the adhesive, it is preferably 85 parts by mass or more, more preferably 90 parts by mass or more, and particularly preferably 95 parts by mass or more. It is particularly preferred that the total amount of polymer A1 and polymer A2 is 100 parts by mass out of a total of 100 parts by mass of polymer A, that is, polymer A consists of polymer A1 and polymer A2.

[0045] The content of polymer A1 is not particularly limited, but from the viewpoint of achieving good adhesive strength of the adhesive and suppressing adhesive residue, it is preferably 20 parts by mass or more, more preferably 25 to 95 parts by mass, and particularly preferably 30 to 90 parts by mass, per 100 parts by mass of the total of polymer A1 and polymer A2. The content of polymer A2 is not particularly limited, but from the same viewpoint, it is preferably 80 parts by mass or less, more preferably 5 to 75 parts by mass, and particularly preferably 10 to 70 parts by mass, per 100 parts by mass of the total of polymer A1 and polymer A2. When polymer A is composed of polymer A1 and polymer A2, from the viewpoint of good adhesive strength of the adhesive and suppression of adhesive residue, the amount of polymer A2 is preferably 10 parts by mass or more, more preferably 10 to 300 parts by mass, and even more preferably 50 to 200 parts by mass per 100 parts by mass of polymer A1.

[0046] The average content of EO units in polymer A is not particularly limited, but is preferably 0 to 80% by mass, more preferably 0 to 70% by mass, still more preferably 0 to 60% by mass, and particularly preferably 0 to 50% by mass. The average content of EO units in polymer A is 13 The content of EO units can be determined by analyzing the monomer composition of the oxyalkylene chains in polymer A through C-NMR measurement. For example, when the oxyalkylene chains in polymer A are composed of EO units and units based on propylene oxide (also referred to as "PO units"), the content of EO units can be calculated based on the area of ​​the peak representing the methylene group of the EO units and the area of ​​the peak representing the methyl group of the PO units. When the polymer A is composed of, for example, the polymer A1 and the polymer A2, the EO unit content of each of the polymer A1 and the polymer A2 is also the same. The average content of EO units in polymer A can be considered to be a value calculated from the amount of EO in the raw materials used to synthesize polymer A. For example, when polymer A consists of polymer A1 and polymer A2, the EO unit content of polymer A can be considered to be the weighted average of the EO unit content of polymer A1 and the EO unit content of polymer A2 based on the compositional proportions (amounts) of polymer A1 and polymer A2.

[0047] The Mn of polymer A is not particularly limited, but from the viewpoints of providing good adhesive strength of the adhesive, suppressing adhesive residue, and forming an adhesive layer with good flexibility, it is preferably 1,000 to 50,000, more preferably 5,000 to 30,000, and particularly preferably 8,000 to 25,000. There are no particular restrictions on the Mw / Mn (molecular weight distribution) of polymer A, but from the viewpoints of being close to 1 and having a narrow molecular weight distribution, the hydroxyl group-terminated urethane prepolymer is less likely to become highly viscous and the synthesis can be made more efficient, the Mw / Mn is preferably 1.25 or less, more preferably 1.22 or less, and particularly preferably 1.20 or less. Furthermore, the degree of unsaturation of polymer A is not particularly limited, but from the viewpoint of good curing properties of the hydroxyl group-terminated urethane prepolymer and suppression of adhesive residue of the adhesive, the closer to 0 meq / g the better, and is preferably 0.020 meq / g or less, more preferably 0.018 meq / g or less, and particularly preferably 0.015 meq / g or less. When polymer A is composed of two or more kinds of oxyalkylene polymers, it is preferable that each of the oxyalkylene polymers has Mn, Mw / Mn and degree of unsaturation within the above ranges.

[0048] The synthesis method for polymer A is not particularly limited. For example, polymer A can be obtained by ring-opening addition polymerization of a compound having a cyclic ether structure, preferably an alkylene oxide, with an initiator having two or more active hydrogens in the presence of a catalyst. When polymer A consists of polymer A1 and polymer A2, a method can also be used in which an initiator having three active hydrogens and an initiator having two active hydrogens are used in combination to perform ring-opening addition polymerization of a compound having a cyclic ether structure to simultaneously produce polymer A1 and polymer A2. From the perspective of more accurately adjusting the blending amounts of polymer A1 and polymer A2, a method is preferred in which polymer A1, obtained by ring-opening addition polymerization of a compound having a cyclic ether structure with an initiator having three active hydrogens, and polymer A2, obtained by ring-opening addition polymerization of a compound having a cyclic ether structure with an initiator having two active hydrogens, are separately synthesized and then mixed.

[0049] The compound having a cyclic ether structure may be linear or branched. The number of carbon atoms in the compound having a cyclic ether structure is not particularly limited, but is preferably 2 to 14, more preferably 2 to 10, and particularly preferably 2 to 4. The compound having a cyclic ether structure is not particularly limited, and examples thereof include ethylene oxide (EO), propylene oxide (PO), 1,2-butylene oxide, 2,3-butylene oxide, methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, lauryl glycidyl ether, hexyl glycidyl ether, and tetrahydrofuran. These may be used alone or in combination of two or more. Among these, EO and PO are preferred.

[0050] When two or more compounds having a cyclic ether structure are used in combination, the arrangement of the oxyalkylene groups derived from each compound in the polymer A may be random or block.

[0051] Examples of the group having an active hydrogen in the initiator include a hydroxyl group, a carboxyl group, and an amino group having a hydrogen atom bonded to a nitrogen atom. These may be used alone or in combination of two or more. Among these, a hydroxyl group is preferred, and an alcoholic hydroxyl group is more preferred. Examples of initiators having three hydroxyl groups include glycerin, trimethylolethane, trimethylolpropane, and 1,2,6-hexanetriol. These may be used alone or in combination of two or more. Examples of initiators having two hydroxyl groups include ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol. These may be used alone or in combination of two or more.

[0052] The number of active hydrogen atoms in the initiator usually corresponds to the number of hydroxyl groups per molecule of the oxyalkylene polymer. Polymer A1 can be synthesized, for example, using glycerin as the initiator. Polymer A2 can be synthesized, for example, using propylene glycol as the initiator. The initiator for the synthesis of the oxyalkylene polymer is 13 The type and amount of polymer A can be identified by C-NMR measurement. 13 The ratio of polymer A1 to polymer A2 can be determined by determining the content of oxyalkylene groups such as EO units and PO units bound to each initiator from information on the type and amount of initiator obtained by C-NMR measurement.

[0053] Ring-opening addition polymerization can be carried out using known catalysts, such as alkali catalysts such as potassium hydroxide, transition metal compound-porphyrin complex catalysts such as complexes obtained by reacting organoaluminum compounds with porphyrins, composite metal cyanide complex catalysts, and catalysts made of phosphazene compounds. Among these catalysts, composite metal cyanide complex (DMC) catalysts are preferred because they tend to produce oxyalkylene polymers with narrow molecular weight distributions and relatively low viscosity. Known compounds can be used as composite metal cyanide complexes, such as zinc hexacyanocobaltate complexes with tert-butanol as a ligand. The synthesis of an oxyalkylene polymer by ring-opening addition polymerization using a DMC catalyst can be carried out by known methods, and for example, the production methods described in WO 2003 / 062301, WO 2004 / 067633, JP 2004-269776, JP 2005-15786, WO 2013 / 065802, JP 2015-10162, etc. can be applied.

[0054] --Oxyalkylene polymer B-- The number of hydroxyl groups per molecule of the oxyalkylene polymer B is 1. As the polymer B, one type of oxyalkylene polymer may be used alone, or two or more types of oxyalkylene polymers may be used. When polymer B is composed of two or more types of oxyalkylene polymers, the average number of hydroxyl groups per molecule of polymer B is not particularly limited, but is preferably 0.1 to 1.0, more preferably 0.5 to 1.0, and particularly preferably 0.8 to 1.0. The number of hydroxyl groups in polymer B is the same as that in polymer A, 13 This can be confirmed by identifying the type and amount of the initiator used as a synthetic raw material through C-NMR measurement. Commercially available products can also be used as the polymer B. Examples of commercially available products of the polymer B include "Preminol S 1011" and "Preminol S 1004F" (manufactured by AGC Inc.).

[0055] The Mn of polymer B is not particularly limited, but from the viewpoints of forming a pressure-sensitive adhesive layer with good flexibility, providing good adhesive strength of the pressure-sensitive adhesive, and suppressing adhesive residue, it is preferably 4,000 to 30,000, more preferably 4,500 to 25,000, and particularly preferably 5,000 to 20,000. There are no particular restrictions on the Mw / Mn of polymer B, but from the viewpoints of being close to 1 and having a narrow molecular weight distribution, the hydroxyl group-terminated urethane prepolymer is less likely to become highly viscous and the synthesis can be made more efficient, the Mw / Mn is preferably less than 1.20, more preferably less than 1.13, and particularly preferably less than 1.10. Furthermore, the degree of unsaturation of polymer B is not particularly limited, but from the viewpoint of good curing properties of the hydroxyl group-terminated urethane prepolymer and suppression of adhesive residue in the adhesive layer, it is preferably 0.015 meq / g or less, more preferably 0.013 meq / g or less, and particularly preferably 0.010 meq / g or less, and the closer to 0 meq / g the better. When polymer B is composed of two or more kinds of oxyalkylene polymers, it is preferable that each of the oxyalkylene polymers has Mn, Mw / Mn and degree of unsaturation within the above ranges.

[0056] The method for synthesizing polymer B is not particularly limited, and it can be obtained, for example, by ring-opening addition polymerization of a compound having a cyclic ether structure, preferably an alkylene oxide, to an initiator having one active hydrogen in the presence of a catalyst. The compound having a cyclic ether structure is the same as that described for polymer A. Preferably, PO is used alone, or EO and PO are used in combination.

[0057] The average content of EO units in polymer B is not particularly limited, but from the viewpoint of obtaining a pressure-sensitive adhesive having good adhesive strength to skin and suppressed crystallinity, it is preferably 0 to 80% by mass, more preferably 0 to 60% by mass, and particularly preferably 0 to 50% by mass. The average content of EO units in polymer B can be determined in the same manner as in the case of polymer A.

[0058] Examples of the group having an active hydrogen in the initiator include the same as those in the case of polymer A. These may be used alone or in combination of two or more. Among these, a hydroxyl group is preferred, and an alcoholic hydroxyl group is more preferred. From the viewpoint of availability, suitable examples of initiators having one hydroxyl group include monohydric alcohols having 2 to 4 carbon atoms, such as n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, and tert-butanol. These may be used alone or in combination of two or more. Among these, n-butanol, sec-butanol, isobutanol, and tert-butanol are preferred. The ring-opening addition polymerization can be carried out by a known method, as in the case of polymer A.

[0059] When polymer A is composed of polymer A1 and polymer A2, for example, the content of polymer A1 is not particularly limited, but from the viewpoint of obtaining a pressure-sensitive adhesive agent having good adhesive strength to skin, the content of polymer A1 is preferably 10 to 45 parts by mass, more preferably 15 to 40 parts by mass, and particularly preferably 30 to 40 parts by mass, per 100 parts by mass of the total of polymer A1, polymer A2, and polymer B in the oxyalkylene polymer. The content of polymer A2 is not particularly limited, but from the same viewpoint, it is preferably 15 to 50 parts by mass, more preferably 30 to 50 parts by mass, and particularly preferably 40 to 50 parts by mass, per 100 parts by mass of the total of polymer A1, polymer A2, and polymer B in the oxyalkylene polymer. The content of polymer B is not particularly limited, but from the same viewpoint, it is preferably 5 to 40 parts by mass, more preferably 10 to 35 parts by mass, and particularly preferably 10 to 20 parts by mass, per 100 parts by mass of the total of polymer A1, polymer A2, and polymer B in the oxyalkylene polymer. The content ratios of polymer A1, polymer A2 and polymer B are preferably polymer A2, polymer A1 and polymer B in descending order.

[0060] -Diisocyanate compounds- The diisocyanate compound used in the synthesis of hydroxyl-terminated urethane prepolymer is an organic compound having two isocyanate groups in one molecule. The diisocyanate compound is not particularly limited, and examples thereof include aliphatic diisocyanate compounds, alicyclic diisocyanate compounds, aromatic diisocyanate compounds, araliphatic diisocyanate compounds, etc. These may be used alone or in combination of two or more.

[0061] The aliphatic diisocyanate compound may be either linear or branched. Specific examples of the aliphatic diisocyanate compound are not particularly limited and include, for example, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, and 3-methylpentane-1,5-diisocyanate. These may be used alone or in combination of two or more. The alicyclic diisocyanate compound is not particularly limited, and examples thereof include isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (HMDI), 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, and 1,3-bis(isocyanatemethyl)cyclohexane. These may be used alone or in combination of two or more. The aromatic diisocyanate compound is not particularly limited, and examples thereof include tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 4,4'-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, dialkyldiphenylmethane diisocyanate, and tetraalkyldiphenylmethane diisocyanate. These may be used alone or in combination of two or more. The aromatic aliphatic diisocyanate compound is not particularly limited, and examples thereof include xylylene diisocyanate and tetramethylxylylene diisocyanate (TMXDI). These may be used alone or in combination of two or more. Among these, from the viewpoint of obtaining a pressure-sensitive adhesive layer having good curability of the hydroxyl group-terminated urethane prepolymer and good flexibility, HDI, IPDI, HMDI and TMXDI are preferred, and HDI is more preferred.

[0062] Furthermore, as the diisocyanate compound, a bifunctional isocyanate-terminated urethane prepolymer obtained by previously reacting the above-mentioned diisocyanate compound with a diol (e.g., ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, etc.) can also be used.

[0063] -Tin-free catalyst- A tin-free catalyst is a urethane catalyst that does not contain tin. In order to obtain an adhesive that is low in toxicity and gentle on the skin, it is preferable that the adhesive does not contain tin or tin compounds.

[0064] The tin-free catalyst is not particularly limited, and examples thereof include tertiary amine catalysts and organometallic catalysts containing metals other than tin. These may be used alone or in combination of two or more. Among these, organometallic catalysts are preferred from the viewpoint of better reaction promotion. The metal contained in the organometallic catalyst containing a metal other than tin is not particularly limited, and examples thereof include zinc, bismuth, titanium, lead, iron, cobalt, and zirconium. These may be used alone or in combination of two or more. Among these, zinc and bismuth are preferred, and zinc is more preferred, from the viewpoints of low toxicity to the skin, ease of handling, and the like.

[0065] The tertiary amine catalyst is not particularly limited, and examples thereof include triethylamine, triethylenediamine, 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), etc. These may be used alone or in combination of two or more. The organometallic catalyst containing a metal other than tin is not particularly limited, and examples thereof include zinc compounds such as zinc carboxylates (e.g., zinc naphthenate, zinc 2-ethylhexanoate), zinc acetylacetonate, etc.; bismuth compounds (e.g., bismuth 2-ethylhexanoate, bismuth neodecanoate, etc.); titanium compounds (e.g., dibutyltitanium dichloride, tetrabutyltitanium, butoxytitanium trichloride, etc.); lead compounds (e.g., lead oleate, lead 2-ethylhexanoate, lead benzoate, lead naphthenate, etc.); iron compounds (e.g., iron 2-ethylhexanoate, iron acetylacetonate, etc.); cobalt compounds (e.g., cobalt benzoate, cobalt 2-ethylhexanoate, etc.); and zirconium compounds (e.g., zirconium naphthenate, etc.). These may be used alone or in combination of two or more.

[0066] The amount of the tin-free catalyst used in the reaction between the oxyalkylene polymer and the diisocyanate compound is not particularly limited, but from the viewpoint of achieving good reaction promotion and reducing the amount of residual metal components, the amount is preferably more than 0.001 part by mass and less than 0.05 part by mass, more preferably 0.005 to 0.045 parts by mass, and particularly preferably 0.01 to 0.04 parts by mass, relative to 100 parts by mass of the oxyalkylene polymer.

[0067] The method for producing the hydroxyl group-terminated urethane prepolymer is not particularly limited, and examples thereof include a method in which an oxyalkylene polymer, a diisocyanate compound, a catalyst, and a solvent are all charged into a reaction vessel at once; and a method in which a diisocyanate compound is subsequently added dropwise to a reaction vessel into which an oxyalkylene polymer, a catalyst, and a solvent have been charged. As a method for producing a hydroxyl-terminated urethane prepolymer, a method in which a diisocyanate compound is added later is preferred from the viewpoint of ease of control of the molecular weight distribution of the hydroxyl-terminated urethane prepolymer due to preferential reaction of low molecular weight components in the synthetic raw materials.

[0068] The solvent used in producing the hydroxyl group-terminated urethane prepolymer is not particularly limited, and examples thereof include ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, aromatic hydrocarbons such as toluene and xylene, etc. These may be used alone or in combination of two or more. When a solvent is used in the production of a hydroxyl group-terminated urethane prepolymer, the amount used is not particularly limited, but from the viewpoint of the uniformity of the reaction system and synthesis efficiency, the amount used is preferably 50 to 500 parts by mass, more preferably 70 to 400 parts by mass, and particularly preferably 80 to 300 parts by mass per 100 parts by mass of the oxyalkylene polymer in total.

[0069] The isocyanate index in the production of a hydroxyl-terminated urethane prepolymer (reaction of an oxyalkylene polymer with a diisocyanate compound) is not particularly limited, but from the viewpoint of efficiently obtaining a hydroxyl-terminated urethane prepolymer with an appropriate molecular chain length, it is preferably less than 100, more preferably 30 to 95, and particularly preferably 50 to 95.

[0070] The reaction temperature in producing the hydroxyl group-terminated urethane prepolymer is not particularly limited, but from the viewpoint of promoting the urethane reaction and suppressing side reactions, it is preferably less than 100°C, more preferably 70 to 95°C, and particularly preferably 75 to 90°C. After the reaction is completed, a reaction terminator such as acetylacetone may be added to deactivate the catalyst.

[0071] The average number of hydroxyl groups per molecule of the hydroxyl-terminated urethane prepolymer is not particularly limited, but from the viewpoint of obtaining an adhesive having good adhesive strength to skin, it is preferably less than 3.0, more preferably 1.7 to 2.9, and particularly preferably 1.8 to 2.5.

[0072] <<Polyisocyanate compounds>> The polyisocyanate compound is a curing agent for the hydroxyl-terminated urethane prepolymer. The polyisocyanate compound is a compound having two or more isocyanate groups in one molecule, and may be used alone or in combination of two or more kinds. As the polyisocyanate compound, a diisocyanate compound is preferred from the viewpoints of availability and reactivity, and a polyisocyanate compound having three or more isocyanate groups in one molecule is preferred from the viewpoints of good adhesive strength of the adhesive and suppression of adhesive residue.

[0073] Specific examples of the diisocyanate compound include the same as the specific examples of the diisocyanate compound constituting the hydroxyl group-terminated urethane prepolymer described above. These may be used alone or in combination of two or more. Examples of polyisocyanate compounds having three or more isocyanate groups in one molecule include derivatives of the above-mentioned diisocyanate compounds, such as isocyanurate-modified compounds, biuret-modified compounds, and allophanate-modified compounds, as well as tri- or higher-functional isocyanate-terminated urethane prepolymers (adducts) that are reaction products of diisocyanate compounds with polyols having three or more hydroxyl groups in one molecule (e.g., trimethylolpropane). These may be used alone or in combination of two or more.

[0074] <<Other ingredients>> The pressure-sensitive adhesive composition may contain other components in addition to the hydroxyl group-terminated urethane prepolymer and the polyisocyanate compound. Examples of the other components include liquid or paste-like components, tackifiers, drugs, plasticizers, antioxidants, antistatic agents, fillers, UV absorbers, light stabilizers, conductivity-imparting agents, leveling agents, transdermal absorption enhancers, solubilizers, and various additives such as colorants. A solvent may also be included. The other components may be used alone or in combination of two or more, and may be blended in amounts within a range that does not impair the effects of the present invention.

[0075] The total content of the hydroxyl group-terminated urethane prepolymer and polyisocyanate compound in the pressure-sensitive adhesive composition (excluding the solvent) is not particularly limited, but from the viewpoint of fully exerting the effects of the present invention, it is preferably 85% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and is also preferably 100% by mass.

[0076] The content of the hydroxyl group-terminated urethane prepolymer relative to the total of the hydroxyl group-terminated urethane prepolymer and the polyisocyanate compound is not particularly limited, but from the viewpoint of fully exerting the effects of the present invention, it is preferably 50 to 98 mass%, more preferably 60 to 95 mass%, and particularly preferably 70 to 92 mass%.

[0077] The content of the polyisocyanate compound relative to the total of the hydroxyl group-terminated urethane prepolymer and the polyisocyanate compound is not particularly limited, but from the viewpoint of fully exerting the effects of the present invention, it is preferably 2 to 50 mass%, more preferably 5 to 40 mass%, and particularly preferably 8 to 30 mass%.

[0078] The pressure-sensitive adhesive composition may contain components that are liquid or pasty at room temperature (25°C).

[0079] The component that is liquid or pasty at room temperature is not particularly limited as long as it is compatible with the hydroxyl group-terminated urethane prepolymer, and examples that can be used include tackifiers, drugs, plasticizers, antioxidants, antistatic agents, fillers, UV absorbers, light stabilizers, conductivity-imparting agents, leveling agents, antibacterial agents, disinfectants, softeners, etc. These may be used alone or in combination of two or more.

[0080] The content of the component that is liquid or pasty at room temperature is preferably, for example, 10 to 100 parts by mass per 100 parts by mass of the total content of the hydroxyl group-terminated urethane prepolymer and the polyisocyanate compound. When the content of the component is within the above range, sufficient flexibility can be imparted to the adhesive layer, resulting in good skin adhesion and suppressing physical damage to the skin when the patch is peeled off from the skin, thereby achieving good releasability.

[0081] The pressure-sensitive adhesive composition preferably further contains a tackifier to improve adhesion to the skin. The tackifier is not particularly limited, and examples thereof include rosin-based, terpene-based, etc. These may be used alone or in combination of two or more. The softening point of the tackifier is not particularly limited, but is preferably 60°C or higher, more preferably 80°C or higher, and particularly preferably 100°C or higher.

[0082] The content of the tackifier is not particularly limited, but is preferably 5 to 50 parts by mass, more preferably 5 to 30 parts by mass, and particularly preferably 5 to 20 parts by mass, per 100 parts by mass of the total content of the hydroxyl group-terminated urethane prepolymer and the polyisocyanate compound.

[0083] The drug is not particularly limited, and examples include drugs contained in ointments, creams, sprays, etc. used on the face, nasal mucosa, etc.; active ingredients contained in cosmetics and quasi-drugs that are effective against blemishes, wrinkles, etc.; etc. These may be used alone or in combination of two or more. Specific examples of the drug are not particularly limited, and include, for example, anti-inflammatory agents (pyridoxine dicaprylate, dipotassium glycyrrhizinate, pyridoxine dipalmitate, glycyrrhizinic acid, diphenhydramine hydrochloride, Phellodendron bark extract, glycyrrhetinyl stearate, lysozyme chloride, aminocaproic acid, ganoderma lucidum extract, coix seed extract, melilot extract, peony extract, angelica acutiloba extract, angelica acutiloba root extract, cnidium rhizome extract, gennoshoko extract, allantoin, and arnica extract), antibacterial agents (shikonin, hinokitiol, cedrol, benzalkonium chloride, benzethonium chloride, photosensitizer No. 201, and adipic acid), sebum secretion inhibitors (estradiol, vitamin B2, vitamin B6, royal jelly extract, riboflavin, and the like), oil-absorbing polysaccharides (shikonin, hinokitiol, cedrol, benzalkonium chloride, benzethonium chloride, photosensitizer No. 201, and adipic acid), and the like. Examples of suitable ingredients include porous powders (such as porous nylon powder and porous cellulose powder), sebum absorbents (such as kaolin, talc, clay, and zinc oxide), exfoliants (such as salicylic acid, sulfur, bentonite, and cyclodextrin), antioxidants (such as dibutylhydroxytoluene, tocopherol acetate, ascorbic acid, benzoic acids, parabens, benzalkonium chloride, and benzethonium chloride), skin roughness improving agents (such as arnica montana extract, licorice extract, retinol, dipotassium glycyrrhizinate, peony extract, sage leaf extract, loquat leaf extract, and rosemary extract), antioxidants (such as vitamins and butylhydroxytoluene), various analgesics and anti-inflammatory agents, antihistamines, corticosteroids, moisturizers, vitamins, fragrances, and beauty ingredients. The cosmetic ingredient is not particularly limited and examples thereof include lecithin, amino acids, kojic acid, proteins, sugars, hormones, placenta extract, extracts from aloe and the like, extracts from loofah and the like, extracts from licorice and the like, diphenhydramine salicylate, diphenhydramine tannate, triprolidine hydrochloride, mequitazine, chlorpheniramine maleate, clemastine fumarate, promethazine hydrochloride, tranilast, sodium cromoglycate, ketotifen, arylsulfatase B, bufexamac, butyl flufenamate, ibuprofen, indomethacin, aspirin, flurbiprofen, ketoprofen, piroxicam, ibuprofen piconol, etc. These may be used alone or in combination of two or more.

[0084] The plasticizer is not particularly limited and can be selected from the viewpoint of compatibility with other components and wettability of the pressure-sensitive adhesive layer to the adherend, and examples thereof include fatty acid esters having 8 to 30 carbon atoms and phosphate esters. These may be used alone or in combination of two or more. The antioxidant is not particularly limited, and examples thereof include phenol-based, amine-based, sulfur-based, and phosphorus-based antioxidants that contribute to suppressing thermal degradation of the adhesive layer. These may be used alone or in combination of two or more. Among these, phenol-based antioxidants are preferred from the viewpoint of low toxicity to the skin. The antistatic agent is not particularly limited, and examples thereof include those that contribute to suppressing damage to the circuit pattern due to electrostatic discharge, such as inorganic salts, ionic liquids containing imidazolium ions, pyridinium ions, ammonium ions, etc., surfactants, etc. These may be used alone or in combination of two or more. The filler is not particularly limited, and examples thereof include talc, calcium carbonate, and titanium oxide. These may be used alone or in combination of two or more. The ultraviolet absorber is not particularly limited, and examples thereof include benzophenone-based, benzotriazole-based, salicylic acid-based, oxalic acid anilide-based, cyanoacrylate-based, triazine-based ultraviolet absorbers, etc. These may be used alone or in combination of two or more. The light stabilizer is not particularly limited, and examples thereof include hindered amine light stabilizers and ultraviolet stabilizers. These may be used alone or in combination of two or more. The conductivity-imparting agent is not particularly limited, and examples thereof include fine metal particles such as silver nanoparticles, which may be used alone or in combination of two or more. The leveling agent is not particularly limited, and examples thereof include polymer leveling agents such as acrylic, vinyl, silicone, and fluorine-based leveling agents. These may be used alone or in combination of two or more.

[0085] The method for producing the pressure-sensitive adhesive composition comprises reacting an oxyalkylene polymer and a diisocyanate compound in the presence of a tin-free catalyst to obtain a hydroxyl-terminated urethane prepolymer, and then mixing the hydroxyl-terminated urethane prepolymer with a polyisocyanate compound to produce the pressure-sensitive adhesive composition. A urethane-based adhesive can be suitably obtained by reacting a hydroxyl-terminated urethane prepolymer with a polyisocyanate compound. When the hydroxyl group-terminated urethane prepolymer and the polyisocyanate compound are mixed, other components that can be contained in the pressure-sensitive adhesive composition described above may also be mixed.

[0086] <Method of manufacturing pressure-sensitive adhesive layer> In one embodiment of the facial patch of the present invention, a urethane-based adhesive obtained by curing the above-mentioned adhesive composition can be used as the adhesive layer. The use of a urethane adhesive tends to reduce the amount of keratin peeling off the adhesive layer after one day of application. The urethane-based adhesive is obtained as a reaction product between the hydroxyl group-terminated urethane prepolymer and the polyisocyanate compound in the adhesive composition. As will be described later, for example, the urethane-based adhesive can be formed as an adhesive layer by applying the adhesive composition onto a support and curing it.

[0087] Depending on the manner of use of the adhesive layer, the adhesive composition may be a one-component type in which a hydroxyl-terminated urethane prepolymer and a polyisocyanate compound as a curing agent are pre-mixed, or a two-component type consisting of a first part containing a hydroxyl-terminated urethane prepolymer and a second part containing a polyisocyanate compound as a curing agent.

[0088] In the reaction between the hydroxyl group-terminated urethane prepolymer and the polyisocyanate compound, a catalyst and a solvent may be used, if necessary. When a catalyst is used, the above-mentioned tin-free urethane catalyst can be used. The catalyst may be the same as or different from the catalyst used in the synthesis of the hydroxyl-terminated urethane prepolymer. If the catalyst used in the synthesis of the hydroxyl-terminated urethane prepolymer remains, the remaining catalyst can also exert a catalytic effect in the reaction between the hydroxyl-terminated urethane prepolymer and the polyisocyanate compound. When a catalyst is added during the reaction of the hydroxyl-terminated urethane prepolymer with the polyisocyanate compound, the amount added is not particularly limited, but is preferably more than 0.001 part by mass and less than 0.05 part by mass, more preferably 0.005 to 0.045 parts by mass, and particularly preferably 0.01 to 0.04 parts by mass, relative to 100 parts by mass of the total of the hydroxyl-terminated urethane prepolymer and the polyisocyanate compound. When a catalyst is added, it is preferable to add a reaction terminator after completion of the reaction to deactivate the catalyst.

[0089] The solvent used in the reaction of the hydroxyl-terminated urethane prepolymer with the polyisocyanate compound may be the same as that used in the synthesis of the hydroxyl-terminated urethane prepolymer described above. The solvent may be the same as or different from that used in the synthesis of the hydroxyl-terminated urethane prepolymer. If the solvent used in the synthesis of the hydroxyl-terminated urethane prepolymer remains, it may be used as is. When a solvent is used, the amount used is not particularly limited, but is preferably 50 to 500 parts by mass, more preferably 70 to 400 parts by mass, and particularly preferably 80 to 300 parts by mass, per 100 parts by mass of the total of the hydroxyl group-terminated urethane prepolymer and the polyisocyanate compound.

[0090] The reaction temperature between the hydroxyl group-terminated urethane prepolymer and the polyisocyanate compound is not particularly limited, but from the viewpoint of promoting the urethane reaction and suppressing side reactions, it is preferably less than 120°C, more preferably 40 to 110°C, and particularly preferably 50 to 100°C.

[0091] The isocyanate index of the polyisocyanate compound to be reacted with the hydroxyl group-terminated urethane prepolymer is not particularly limited, but is preferably greater than 100, more preferably 101 to 1,500, and particularly preferably 105 to 1,000.

[0092] The formation of the pressure-sensitive adhesive layer is not particularly limited and can be carried out using a known method, for example, a method of applying a pressure-sensitive adhesive composition to a release liner, curing it to form a pressure-sensitive adhesive layer, and laminating a support; a method of applying a pressure-sensitive adhesive composition to a support, curing it to form a pressure-sensitive adhesive layer, and laminating a release liner; etc. These may be used alone or in combination of two or more. The method for applying the pressure-sensitive adhesive composition is not particularly limited, and can be any known method such as bar coating, knife coating, roll coating, blade coating, die coating, microgravure coating, comma coating, slot die coating, lip coating, cast coating, etc. These may be used alone or in combination of two or more. After application, the adhesive composition is preferably cured by, for example, hot air drying at 40 to 80° C. to sufficiently volatilize the solvent contained in the adhesive composition, thereby forming an adhesive layer.

[0093] The pressure-sensitive adhesive layer is preferably subjected to a crosslinking treatment to impart an appropriate cohesive force. Crosslinking treatments include physical crosslinking by irradiation with ionizing radiation such as electron beams, γ-rays, and X-rays, and chemical crosslinking using a crosslinking agent. From the viewpoint of good handling and reproducibility, chemical crosslinking using a crosslinking agent is preferred. For example, the crosslinking treatment is carried out by adding a crosslinking agent to a pressure-sensitive adhesive composition containing the materials constituting the pressure-sensitive adhesive layer and then heating the composition. As such a crosslinking agent, crosslinking agents used in crosslinking treatments, such as isocyanate-based crosslinking agents, peroxide-based crosslinking agents, and metal chelate-based crosslinking agents, can be used.

[0094] The adhesive layer crosslinked as described above maintains a suitable balance between skin adhesion and cohesion depending on the degree of crosslinking, but the molecular weight and molecular weight distribution of the urethane-based adhesive also affect these adjustments.

[0095] When the facial patch of this embodiment has an adhesive layer formed on the first surface of the support and another adhesive layer (second adhesive layer) formed on the other surface (second surface) of the support, the thickness of the second adhesive layer is not particularly limited, but is preferably 30 to 80 μm, and more preferably 40 to 70 μm. The second pressure-sensitive adhesive layer may be formed partially on the second surface of the support, or may be formed over the entire second surface of the support. The adhesive forming the second adhesive layer is not particularly limited, and examples thereof include urethane adhesives, acrylic adhesives, silicone adhesives, rubber adhesives (natural rubber, synthetic rubber, mixtures thereof, etc.), polyester adhesives, polyether adhesives, polyamide adhesives, fluorine adhesives, etc. These may be used alone or in combination of two or more.

[0096] The total thickness of the support and the adhesive layer is not particularly limited, but is preferably 30 to 200 μm, more preferably 40 to 180 μm, and particularly preferably 50 to 150 μm. If the total thickness of the support and the adhesive layer is above the lower limit, the strength of the facial patch will be insufficient, and the facial patch may tear when being stuck to or peeled off from facial skin, and the adhesiveness to facial skin will be insufficient, resulting in insufficient adhesion to the face, which secretes a lot of sebum. On the other hand, if the total thickness of the support and the adhesive layer is below the upper limit, the facial patch will not adhere well to fine irregularities on the surface of the facial skin, such as skin grooves, making the stuck state more noticeable and causing a greater sense of discomfort, and reducing problems such as damage to the skin or pain when the facial patch is peeled off from the skin.

[0097] (peeling layer) The surface of the adhesive layer is preferably covered with a release layer to protect the surface of the adhesive layer before use of the facial patch, and the release layer is appropriately peeled off from the surface of the adhesive layer when the facial patch is used. The release layer may be any of those used in known adhesive tapes for skin, etc. Examples of the release layer include fine paper or glassine paper coated with a release agent such as silicone resin or fluororesin on its surface; parchment paper; resin anchor coated or polyethylene-laminated fine paper coated with a release agent such as silicone resin or fluororesin on its surface; transparent resin films such as polyester films (for example, the release liner used in the examples of the present application); polyethylene terephthalate films with silicone-treated surfaces; and laminates of polyethylene and paper with silicone-treated surfaces. The release layer may be two or more sheets of the same or different thicknesses to protect the adhesive layer. In addition, the release layer may have a slit to improve handling (i.e., ease of releasability from the adhesive layer), or may be formed with an area larger than the facial patch and have a gripping portion on the periphery. Furthermore, for the purpose of improving handling properties and printability, the release layer may be provided with irregularities by sandblasting or the like on the surface of the release layer facing the adhesive layer or on the surface opposite to the adhesive layer. Furthermore, the release layer may be provided as a single large sheet, and multiple combinations of adhesive layer, support and carrier film may be arranged on top of it, in which case the release layer will be shared by multiple patches. The release layer can also be used to facilitate the formation of the adhesive layer in the method for producing a facial patch of the present invention. That is, a laminated sheet comprising an adhesive layer and a release layer is produced by, for example, applying an adhesive composition for forming an adhesive layer to the surface of a previously prepared release layer, and then a support is laminated on the surface of the adhesive layer, thereby obtaining a facial patch comprising a support, adhesive layer, and release layer in this order. The thickness of the release layer is not particularly limited, but from the viewpoint of protecting the pressure-sensitive adhesive layer and facilitating peeling during use, it is preferably 5 to 200 μm, more preferably 10 to 100 μm, and particularly preferably 20 to 50 μm.

[0098] (Other layers) The facial patch of this embodiment may include layers other than the support, adhesive layer, and release layer (for example, a carrier film) as long as the effects of the present invention are achieved.

[0099] ((Carrier film)) The facial patch of the present invention further comprises a carrier film adjacent to the support on the side of the support opposite to the adhesive layer, thereby improving the ease of handling of the facial patch and its application to the skin. That is, when applying the facial patch to the skin, the support may wrinkle or the facial patch may bend, causing the adhesive layers to adhere to each other. However, by providing the carrier film adjacent to the support, the facial patch is provided with a carrier film, a support, an adhesive layer and a release layer in this order, and the shape retention of the facial patch is improved, thereby preventing such problems. The carrier film is used by first peeling off the release layer from the facial patch, pressing the adhesive layer against the skin of the face to apply the facial patch, and then peeling off the carrier film from the support. The material for forming the carrier film is not particularly limited, and a material for forming a release layer can be used, such as polyurethane, polyethylene, polypropylene, ionomer, polyamide, polyvinyl chloride, polyvinylidene chloride, ethylene-vinyl acetate copolymer, thermoplastic polyester, polytetrafluoroethylene, etc. Also, a laminate of these films and paper can be used. The carrier film is preferably a polyester film from the viewpoint of improving ease of handling and application to the skin, and it is also preferable that the surface facing the support is matte-finished so that the carrier film can be easily peeled off from the support after the facial patch has been applied. The carrier film and the support are preferably formed so as to be peelable by thermocompression bonding, adhesion, etc. In order to adjust the peel strength between the carrier film and the support, the surface of the carrier film facing the support may be coated with an adhesive, a liquid plasticizer, a release agent, etc., or may be subjected to other surface treatments. The thickness of the carrier film is not particularly limited, but is preferably 20 to 500 μm or more, and more preferably 40 to 500 μm.

[0100] When the facial patch of the present invention comprises a carrier film, the size of the carrier film may be the same as that of the support, or may be larger than that of the support. Since the carrier film is larger than the support, the carrier film can be used as a gripping portion of the patch, making it easier to peel the adhesive layer of the facial patch from the release layer, and the adhesive layer of the facial patch can be attached to the skin without the fingers touching the adhesive. Here, "the carrier film is larger than the support" means that the entire surface of the carrier film does not cover the support, in other words, that the carrier film has a portion that does not cover the support. For example, in addition to the case where the area of ​​the carrier film is larger than the area of ​​the support (in this case, a portion of the carrier film covers the support), the carrier film can be provided in a pattern such as a lattice, with the edges of the lattice extending beyond the support, or the carrier film can be provided to cover the edge of the support so as to extend beyond the support. The carrier film may be provided so as to cover the support by dividing it into multiple sheets or by partially overlapping them. In addition, a sheet with a cutout or slit may be placed on the upper surface of the carrier film (the surface opposite the support) to further improve handling.

[0101] The force required to peel the release layer from the adhesive layer of the facial patch (peeling force of the release layer) is set to be smaller than the force required to peel the carrier film from the support of the facial patch (peeling force of the carrier film). By setting it in this way, after the release layer is peeled from the adhesive layer of the facial patch, the carrier film remains integrally on the support, and the facial patch has a certain degree of rigidity until it is attached to the skin, making it easy to handle.

[0102] In addition, in the facial patch of this embodiment, it is preferable that the adhesive layer is protected until use in order to prevent contamination of the surface of the adhesive layer.As a method for protecting the adhesive, for example, a method of bonding a release layer to the adhesive layer for protection can be mentioned.In addition, when only one side is adhesive, the side of the support on which the adhesive layer is not formed can be subjected to a release treatment, and the adhesive layer can be bonded to this side, and the facial patch can be rolled up to protect the adhesive layer.In addition, when both sides are adhesive, one release-treated side of a release layer having release-treated surfaces on both sides can be bonded to one adhesive surface, and the facial patch can be rolled up so that the other release-treated side of the release layer comes into contact with the other adhesive surface, to protect both adhesive layers.

[0103] (Manufacturing method for facial patches) The method for producing the facial patch of the present invention is not particularly limited, but from the viewpoint of production efficiency, a method including a step of forming an adhesive layer on the upper surface of a release layer is preferred. Specifically, a preferred method is to run a previously formed release layer in one direction, apply an adhesive that will form the adhesive layer on the upper surface of the release layer, dry and remove the adhesive to form the adhesive layer, and then laminate a support (which may be laminated with a carrier film). The facial patch of the present invention may be produced by, for example, laminating a carrier film, a support, an adhesive layer, and a release layer in this order using the method described above, and then winding it up into a roll to obtain a roll-shaped facial patch, or it may be cut into a desired shape, such as a substantially rectangular or circular shape, to obtain a substantially rectangular or circular facial patch. Alternatively, the facial patch may be further sealed in a bag to obtain a facial patch. [Example]

[0104] The present invention will be specifically described below based on examples, but the present invention is not limited to the following examples and various modifications are possible within the scope of the present invention. In the following, "parts" and "%" mean "parts by mass" and "% by mass", respectively.

[0105] [Preparation of support] A polyurethane sheet, a nonwoven fabric sheet, and a polyethylene sheet, one surface of which was plasma-treated, were prepared as supports 1 to 3. Support 1 was a porous sheet having open cells.

[0106] [Measurement method] The methods for measuring various physical properties in the following synthesis examples are as follows.

[0107] <Number average molecular weight (Mn) and weight average molecular weight (Mw)> Mn and Mw were measured by gel permeation chromatography (GPC) under the following measurement conditions (polystyrene equivalent), and the molecular weight distribution (Mw / Mn) was calculated from these values. [Measurement conditions] Equipment used: "HLC-8320GPC", manufactured by Tosoh Corporation Column used: "TSKgel (registered trademark) SuperMultiporeHZ-M", manufactured by Tosoh Corporation Detector: Refractive index (RI) detector Detection temperature: 40℃ Eluent: tetrahydrofuran ·Flow rate: 0.350mL / min Sample concentration: 0.5% by mass Sample injection volume: 10 μL Standard sample: Polystyrene

[0108] <Ethylene oxide (EO) unit content> The EO unit content of each oxyalkylene polymer was determined based on the amounts of propylene oxide (PO) and EO used in the synthesis, with the amount of EO being considered as the EO unit content in the oxyalkylene polymer. The EO unit content of the hydroxyl-terminated urethane prepolymer was determined as the weighted average of the EO unit content in each component of the raw material.

[0109] <Hydroxyl value> The hydroxyl value was determined in accordance with Method B (automatic potentiometric titration) of JIS K 1557-1:2007.

[0110] <Unsaturation degree> The degree of unsaturation was measured in accordance with JIS K 1557-3:2007.

[0111] <Average number of hydroxyl groups per molecule of oxyalkylene polymer A> The number of hydroxyl groups per molecule of each of the oxyalkylene polymers A1 and A2 used as the oxyalkylene polymer A (the number of hydroxyl groups per molecule of the initiator used in the synthesis of each oxyalkylene polymer) was weighted and averaged based on the amount of each oxyalkylene polymer used, and the average number of hydroxyl groups per molecule of the oxyalkylene polymer A was determined.

[0112] <Average number of hydroxyl groups per molecule of hydroxyl-terminated urethane prepolymer> The number of hydroxyl groups per molecule of each oxyalkylene polymer (oxyalkylene polymers A1, A2, and B) used in the synthesis of the hydroxyl-terminated urethane prepolymer was weighted and averaged based on the blending amount of each oxyalkylene polymer, and this value was considered to be the average number of hydroxyl groups per molecule of the hydroxyl-terminated urethane prepolymer.

[0113] [Substances used] Details of the synthesis examples and materials used in the examples are given below. TBA-DMC catalyst: zinc hexacyanocobaltate complex with tert-butanol as a ligand Glycerin Propylene glycol n-Butanol Propylene oxide (PO) Ethylene oxide (EO) Adsorbent: Synthetic magnesium silicate; "Kyoward (registered trademark) 600S" manufactured by Kyowa Chemical Industry Co., Ltd. Urethane catalyst: Zinc (Zn)-containing urethane catalyst (zinc carboxylate); "K-KAT XK627", manufactured by KING INDUSTRIES Diisocyanate compound: hexamethylene diisocyanate (HDI), "Duranate (registered trademark) 50M-HDI", manufactured by Asahi Kasei Corporation ·toluene Ethyl acetate Curing agent (polyisocyanate compound): HDI polyisocyanate, "Duranate E402-80B" manufactured by Asahi Kasei Corporation; solid content approximately 80% by mass Support 1: Polyurethane (PU) ·Support 2: Non-woven fabric Support 3: Polyethylene

[0114] [Synthesis of oxyalkylene polymer] (Synthesis Example 1-1) 1000 g of glycerin as an initiator and a TBA-DMC catalyst (metal concentration 46 mass ppm) were placed in a pressure vessel, and after replacing the atmosphere in the vessel with nitrogen, the reaction solution was heated to 135°C while stirring, and 120 g of propylene oxide (PO) was added to cause a reaction. After the temperature rise of the reaction liquid stopped, it was cooled to 135°C, and while stirring the reaction liquid, 3782.4 g of PO and 945.6 g of ethylene oxide (EO) were added to the vessel. After confirming that the internal pressure had stopped changing, an adsorbent was added, neutralization and catalyst removal were carried out, and oxyalkylene polymer 1-1, which is polymer A1, was obtained.

[0115] (Synthesis Example 1-2) An oxyalkylene polymer 1-2, which is polymer A2, was synthesized in the same manner as in Synthesis Example 1-1, except that the initiator in Synthesis Example 1-1 was changed from glycerin to propylene glycol.

[0116] (Synthesis Example 1-3) An oxyalkylene polymer 1-3, which is polymer A1, was synthesized in the same manner as in Synthesis Example 1-1, except that EO was not added and the amount of EO added was added as PO.

[0117] (Synthesis Example 1-4) An oxyalkylene polymer 1-4, which is polymer A2, was synthesized in the same manner as in Synthesis Example 1-2, except that EO was not added and the amount of EO added was added as PO.

[0118] (Synthesis Example 1-5) Oxyalkylene polymer 1-5, which is polymer B, was synthesized in the same manner as in Synthesis Example 1-1, except that in Synthesis Example 1-1, the initiator was changed from glycerin to n-butanol, and after cooling the reaction solution, EO was not added but 2364 g of PO was added. Table 1 shows various physical properties of oxyalkylene polymers 1-1 to 1-5.

[0119] [Table 1]

[0120] [Synthesis of hydroxyl-terminated urethane prepolymer] (Synthesis Example 2-1) A reaction vessel equipped with a thermometer, a stirrer, and a condenser was charged with 36.0 parts by mass of oxyalkylene polymer 1-1, 48.0 parts by mass of oxyalkylene polymer 1-2, 16.0 parts by mass of oxyalkylene polymer 1-5, 50.6 parts by mass of toluene, and 50.6 parts by mass of ethyl acetate, and 0.038 parts by mass of a zinc (Zn)-containing urethanization catalyst was added and mixed at 40°C. After that, 1.7 parts by mass of HDI (isocyanate index 85) was added, and the mixture was allowed to react at 80°C. The average number of hydroxyl groups per molecule of the blended oxyalkylene polymer A (oxyalkylene polymers A1 and A2) was 2.4, and the average number of hydroxyl groups per molecule of the oxyalkylene polymers (oxyalkylene polymers A1, A2 and B) was 2.2. The mixture was appropriately diluted with ethyl acetate and kept at 80°C for 7 hours to react, yielding a 50% by mass solution of a transparent hydroxyl-terminated urethane prepolymer U1 (oxyalkylene polymer (oxyalkylene polymers A1, A2, and B) with an average number of hydroxyl groups per molecule of 2.2 and an EO unit content of 16.5% by mass (represented as "17% by mass" in Table 3)).

[0121] (Synthesis Example 2-2) A solution of hydroxyl-terminated urethane prepolymer U2 was produced in the same manner as in Synthesis Example 2-1 using the formulation shown in Table 2. The average number of hydroxyl groups per molecule of the oxyalkylene polymers (oxyalkylene polymers A1, A2, and B) of hydroxyl-terminated urethane prepolymer U2 was 2.2, and the EO unit content was 7.0% by mass (represented as "7% by mass" in Table 3).

[0122] Table 2 shows the blending compositions of the oxyalkylene polymer, diisocyanate compound, and catalyst in Synthesis Examples 2-1 and 2-2.

[0123] [Table 2]

[0124] [Manufacturing of facial patches for evaluation] (Example 1) A liquid (adhesive composition) obtained by mixing 100 parts by mass of a 50% by mass solution of hydroxyl-terminated urethane prepolymer U1 and 5 parts by mass of a curing agent was degassed, and then coated with a knife coater onto a polyester film (38 μm thick) release liner and dried at 100° C. for 2 minutes to form an adhesive layer 25 μm thick. The adhesive layer thus formed was then transferred and attached to the plasma-treated surface of support 1, and left at 60° C. for 72 hours to obtain a facial patch of Example 1 (a facial patch having an adhesive layer formed only on one surface and no adhesive layer formed on the other surface).

[0125] (Example 2) A facial patch of Example 2 was prepared in the same manner as in Example 1, except that Support 1 was changed to Support 2. However, instead of transferring the formed pressure-sensitive adhesive layer to the plasma-treated surface of Support 1, the formed pressure-sensitive adhesive layer was transferred to the nonwoven fabric surface of Support 2.

[0126] (Example 3) A facial patch of Example 3 was produced in the same manner as in Example 1, except that Support 1 was changed to Support 3. However, instead of transferring the formed pressure-sensitive adhesive layer to the plasma-treated surface of Support 1, the formed pressure-sensitive adhesive layer was transferred to the corona-discharge-treated surface of Support 3.

[0127] (Examples 4-6) Facial patches of Examples 4 to 6 were prepared in the same manner as Examples 1 to 3, respectively, except that the hydroxyl-terminated urethane prepolymer U1 was changed to the hydroxyl-terminated urethane prepolymer U2.

[0128] (Examples 7-9) Facial patches of Examples 7 to 9 were prepared in the same manner as Examples 1 to 3, respectively, except that the liquid (urethane adhesive composition) obtained by mixing 100 parts by mass of a 50% by mass solution of hydroxyl-terminated urethane prepolymer U1 and 5 parts by mass of a curing agent was changed to 100 parts by mass of an acrylic adhesive solution (acrylic adhesive composition: solids content 40% by mass) prepared as follows. A homogeneous acrylic adhesive solution was prepared by blending 100 parts by weight of an acrylic copolymer (a copolymer consisting of isononyl acrylate:2-methoxyethyl acrylate:acrylic acid=65 parts by weight:30 parts by weight:5 parts by weight) with 20 parts by weight of glyceryl tricaprylate, 10 parts by weight of a rosin ester (trade name: Haritac PCJ, manufactured by Harima Chemicals Co., Ltd.) as a tackifier, and 0.07 parts by weight of a trifunctional isocyanate compound (trade name: Coronate HL, manufactured by Tosoh Corporation) as a crosslinker in toluene. 100 parts by weight of the prepared acrylic adhesive solution (solid content 40% by weight) was used as the acrylic adhesive composition.

[0129] [Evaluation of facial patches] The facial patches produced in the above examples were subjected to the following various evaluations. The evaluation results are shown in Table 3. Examples 1 to 6 are working examples, and Examples 7 to 9 are comparative examples.

[0130] <Adhesive strength> The release liner was peeled off from the facial patch (100 mm long, 15 mm wide), and one surface (first side) on which the adhesive layer was formed was placed on the skin of the facial cheeks (facial skin) of a human (3 subjects) that had been thoroughly wiped dry after washing their face.The other surface (second side) on which the adhesive layer was not formed was then pressed against the skin using a rubber roller, which was moved back and forth once at a load of 2 kg and a speed of 300 mm / min. After leaving it to stand for 20 minutes, the facial patch was peeled off at a peeling angle of 90° and a speed of 300 mm / min to measure adhesive strength when the adherend was human (3 subjects) facial cheek skin that had been thoroughly wiped dry after face washing, according to a method in accordance with JIS Z 0237: 2009. Adhesive strength was measured using a Tensilon universal material testing machine RTG1310 (manufactured by A&D Co., Ltd.). The humans (three subjects) were: (1) male, Japanese, age in their 30s; (2) male, Japanese, age in their 20s; and (3) female, Japanese, age in their 30s. The average value of three measurements is shown in Table 3. The measured adhesive strength was evaluated according to the following evaluation criteria. The evaluation results are shown in Table 3. [Evaluation criteria (against skin)] A: 0.5~2.8N / 15mm B: Less than 0.5N / 15mm C:2.8N / 15mm or more In the case of rating A, the adhesive strength to the facial skin was moderate and it can be said to be gentle on the skin. On the other hand, in the case of rating B, the adhesive strength to the facial skin was insufficient. In addition, in the case of rating C, it was difficult to peel off from the facial skin and sometimes caused pain when peeling off.

[0131] <Skin observation> In an atmosphere of 23°C and 50% RH, test pieces of the facial patch (20 mm long, 15 mm wide) were applied to the facial cheek skin of humans (3 subjects) that had been thoroughly wiped dry after washing their faces. After one hour, the test pieces were removed from the skin, and the condition of the facial cheek skin was visually observed. The humans (three subjects) were: (1) male, Japanese, age in their 30s; (2) male, Japanese, age in their 20s; and (3) female, Japanese, age in their 30s. The observation results were evaluated according to the following criteria. The evaluation results are shown in Table 3. [Evaluation criteria (skin observation)] A: No change from before the test piece was attached. B: Some people had redness on the skin of their face and cheeks. C: Some people had glue residue (adhesive residue).

[0132] <Applying sensation> Each facial patch was cut into a size of 10 mm x 50 mm to prepare a test sample. Next, the release liner was peeled off and the adhesive layer of the test sample was applied to the cheek skin (facial skin) of humans (3 subjects) who had thoroughly wiped off moisture after washing their faces.The subjects then pressed the cheek skin from the oral cavity side with their tongue and evaluated the adhesion feeling according to the following criteria. The humans (three subjects) were: (1) male, Japanese, age in their 30s; (2) male, Japanese, age in their 20s; and (3) female, Japanese, age in their 30s. The evaluation results are shown in Table 3. [Evaluation criteria (applied feel)] 5: No tightness at all 4: I feel a slight tension that doesn't bother me. 3: I feel a little tight, but I can still live my life. 2: It bothers me, but I can tolerate the tightness without having to remove it. 1: I feel a tightness that I can't bear without peeling it off

[0133] <Amount of keratin peeled after one day of application> In the same manner as in the adhesive force measurement described above, the adhesive layer of the facial patch was pressed onto the facial cheek skin (facial skin) of humans (3 subjects) that had been thoroughly wiped dry after washing their faces, and the rest time after pressing the facial patch was changed from 20 minutes to 1 day, and the facial patch was peeled off in the same manner as in the adhesive force measurement described above. A measurement sample measuring 20 mm in length and 15 mm in width was cut out from the peeled facial patch, and the protein amount [mg / cm ] was measured by the Lowry method using a "Protein Assay Lowry Kit" (manufactured by Nacalai Tesque, Inc.). 2 ] was measured and used as the amount of keratin peeled off. The amount of keratin peeled after one day of application was evaluated according to the following evaluation criteria. The average values ​​of the three measurements are shown in Table 3. The amount of keratin peeled after one day of application was evaluated according to the following criteria. The evaluation results are shown in Table 3. [Evaluation criteria (amount of keratin peeled after one day of application)] A: 0.060 mg / cm 2 below B: 0.060 mg / cm 2 super C: Unmeasurable (peeling) In the case of rating A, it can be said that the stress of the adhesive layer on the skin of the face and cheeks is sufficiently small. In the case of rating B, a lot of keratin on the skin of the face and cheeks peeled off, causing a lot of stress on the skin of the face and cheeks and sometimes causing pain when peeling off. In the case of rating C, it could not be attached to the skin of the face and cheeks for a day and peeled off halfway through, so it could not be evaluated.

[0134] <Moisture permeability> The moisture permeability of the facial patch from which the release liner had been removed was measured using a method in accordance with JIS Z 0208: 1976. Specifically, a circular test piece of the facial patch, with a diameter approximately 10 mm larger than the inner diameter of the cup, was placed over a cup containing approximately 50 g of moisture absorbent (calcium chloride), and the cup was screwed in place using a rubber packing and ring, and measurement was carried out in a constant temperature and humidity chamber at 40°C and 90% RH. The moisture permeability was calculated according to the following formula: Moisture permeability [g / (m 2 ·day)]=W×240000 / S In the formula, S is the area of ​​the cup opening (moisture permeability area [cm 2 ]), and W represents the mass gain of the test piece per hour [g / hr]. Table 3 also shows the moisture permeability evaluation based on the following evaluation criteria. [Evaluation criteria] A: 1500g / (m 2 1 day or more B: 1000g / (m 2 ·day) or more 1500g / (m 2 less than 1 day C: 1000g / (m 2 less than 1 day If the rating is A, it can be said that the material has good moisture permeability and places a sufficiently small burden on the skin.

[0135] The moisture permeability of only the adhesive layer of the facial patch was measured as follows. In the production of the facial patches for evaluation, a coarse-meshed nylon net, which is considered not to affect the moisture permeability (no support), was used instead of supports 1 to 3 (polyurethane (PU), nonwoven fabric, polyester), and other than that, facial patches were produced in the same manner as the production of the facial patches for evaluation. The release liner was peeled off from the obtained facial patch to obtain a test piece (considered to have no support), and the moisture permeability was measured in the same manner as the measurement of the moisture permeability of the adhesive sheet described above, and this measurement value was considered to be the moisture permeability of the adhesive layer alone. As a result, the moisture permeability of only the adhesive layer of the facial patch was 4500 g / (m 2 ·day), and in Examples 4 to 6, it is 4300 g / (m 2 ·day).

[0136] <Cytotoxicity> A cytotoxicity test (cell line: V79 cells, medium: MEM10 medium) was conducted on the adhesive layer using the extraction colony formation method in accordance with ISO 10993-5:2009 "Biological evaluation of medical devices - Part 5: In vitro cytotoxicity tests" to determine the colony formation rate. The test liquid used was an extract obtained by extracting 1 g of the adhesive layer with a culture medium at 37°C for 24 hours. Table 3 shows the average colony formation rate based on three measurements, evaluated according to the following criteria. [Evaluation criteria] A: 70% or more B: 50% or more but less than 70% C: Less than 50% In the cases of ratings A and B, there is no or very weak cytotoxicity, so it can be said that the biosensor with an adhesive layer has little effect on the skin. On the other hand, in the case of rating C, the cytotoxicity is stronger, so it cannot be said that the facial patch with an adhesive layer has little effect on the skin.

[0137] [Table 3]

[0138] As can be seen from the evaluation results shown in Table 3, the facial patches of Examples 1 to 6 had appropriate adhesive strength to facial skin, showed good skin observation results, and sufficiently reduced the amount of keratin peeling. [Industrial Applicability]

[0139] The facial patch of this embodiment has appropriate adhesive strength to facial skin, provides good skin observation results, and has excellent moisture permeability, so it can be applied to areas of the face where sebum is secreted in large amounts. In particular, it can be used as a facial patch for the T-zone or U-zone, which is applied to i) the T-shaped area from the forehead to the bridge of the nose where sebum is secreted in greater amounts than in other areas and so sebum tends to accumulate, resulting in noticeable "makeup breakdown," "greasiness," and the occurrence of "acne," and ii) the U-shaped area such as the chin where sebum is secreted less but where "acne" is likely to occur in adult men and women, i.e., the so-called T-zone or U-zone. Furthermore, the facial patch of the present invention has a good adhesion feel, and by applying it to the face after washing the face to remove sebum, it is possible to prevent sebum from accumulating at the application site or to prevent the skin from becoming "shiny." Furthermore, by applying the patch after washing the face and then applying makeup over the patch, the skin underneath the facial patch can be covered, making it less noticeable, and therefore the facial patch can be applied after washing the face.

[0140] The facial patch of the present invention may be used to attach a wearable device to the skin of the user's face. The wearable device to be attached to the skin of the face is not particularly limited, and examples thereof include a biosensor, an environmental sensor, etc. These may be used alone or in combination of two or more types. The detection target of the biosensor is not particularly limited, and examples include cardiac potential, pulse wave, body temperature, acceleration, heart rate interval, pulse rate interval, respiratory rate, electrocardiogram, electromyogram, activity level, blood pressure, electroencephalogram, etc. These may be used alone or in combination of two or more.

Claims

1. A support, a pressure-sensitive adhesive layer, and a release layer are provided in this order, The facial patch, wherein the adhesive layer contains a urethane-based adhesive.

2. 2. The facial patch according to claim 1, wherein the adhesive strength of the adhesive layer to facial skin is 0.5 to 2.8 N / 15 mm.

3. 3. The facial patch according to claim 1, wherein the adhesive layer has an average content of ethylene oxide-based structural units of 60% by mass or less.

4. 3. The facial patch according to claim 1, wherein the urethane-based adhesive is a cured product of an adhesive composition containing a hydroxyl-terminated urethane prepolymer and a polyisocyanate compound.

5. The facial patch according to claim 4, wherein the pressure-sensitive adhesive composition has an average content of ethylene oxide-based structural units of 60% by mass or less.

6. 5. The facial patch according to claim 4, wherein the hydroxyl-terminated urethane prepolymer is a reaction product of an oxyalkylene polymer and a diisocyanate compound in the presence of a tin-free catalyst.

7. The facial patch according to claim 6, wherein the tin-free catalyst contains at least one of zinc and bismuth.

8. The facial patch according to claim 6, wherein the oxyalkylene polymer has an average content of structural units based on ethylene oxide of 60% by mass or less.

9. 7. The facial patch according to claim 6, wherein the oxyalkylene polymer has an average number of hydroxyl groups per molecule of 1.5 to 3.

0.

10. The facial patch according to claim 6, wherein the oxyalkylene polymer comprises an oxyalkylene polymer A having an average number of hydroxyl groups per molecule of 2.0 or more, and an oxyalkylene polymer B having an average number of hydroxyl groups per molecule of 1.

11. The facial patch according to claim 10, wherein the oxyalkylene polymer A comprises an oxyalkylene polymer A1 having 3 hydroxyl groups per molecule and an oxyalkylene polymer A2 having 2 hydroxyl groups per molecule.

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