Adhesive composition, production method therefor, adhesive, patch, and transdermal absorption patch

Abstract

Provided is an adhesive composition comprising a hydroxyl group-terminated urethane prepolymer, a solvent, and a healing agent, said adhesive composition having a viscosity at 25°C of 2,500-85,000 mPa·s.

Description

Adhesive composition and method for producing the same, as well as adhesive, adhesive patch, and transdermal absorption patch

[0001] The present invention relates to an adhesive composition and a method for producing the same, as well as an adhesive, a patch, and a transdermal absorption patch, and in particular to an adhesive composition having excellent dispersibility for a healing agent and a method for producing the same, as well as an adhesive, a patch, and a transdermal absorption patch.

[0002] A transdermal absorption patch is a type of preparation that allows stable administration of a healing agent through the skin for a long period of time. The transdermal absorption patch is provided with an adhesive that is a cured product of an adhesive composition containing the healing agent, and from the viewpoint of properly exerting the efficacy of the healing agent, the adhesive composition is required to have excellent dispersibility of the healing agent.

[0003] For example, Patent Document 1 discloses a composition containing a random copolymer that can maintain shear strength and low-temperature flow properties despite the addition of a small amount of plasticizer, a therapeutic agent, and an antioxidant. The random copolymer disclosed in Patent Document 1 is prepared by polymerizing at least 70% by weight, based on the weight of the random copolymer, of a first monomer that is butyl acrylate monomer, 2-ethylhexyl acrylate monomer, octyl acrylate monomer, or isooctyl acrylate monomer, and at least 18% by weight, based on the weight of the random copolymer, of a second monomer that is methyl methacrylate monomer, butyl methacrylate, or isobutyl methacrylate, in the presence of a polymerization initiator.

[0004] Special Publication No. 2017-526783

[0005] However, the composition described in Patent Document 1 was not designed with the dispersibility of healing agents in mind, and therefore, a pressure-sensitive adhesive composition with excellent dispersibility of healing agents has not yet been obtained, and there is a strong demand for the development of such a composition.

[0006] In view of the above problems, the present invention aims to provide an adhesive composition having excellent dispersibility of a healing agent, a method for producing the same, an adhesive, a patch, and an adhesive transdermal absorption patch.

[0007] As a result of intensive research into solving the above-mentioned problems, the inventors have found that the above-mentioned problems can be solved by adjusting the viscosity of an adhesive composition containing a predetermined hydroxyl-terminated urethane prepolymer, a solvent, and a healing agent to fall within a predetermined range, and have thus completed the present invention.

[0008] The present invention provides the following: [1] A pressure-sensitive adhesive composition containing a hydroxyl-terminated urethane prepolymer, a solvent, and a healing agent, wherein the pressure-sensitive adhesive composition has a viscosity of 2500 to 85,000 mPa·s at 25°C. [2] The pressure-sensitive adhesive composition according to [1] above, wherein the pressure-sensitive adhesive composition has a content of structural units based on ethylene oxide of 60% by mass or less. [3] The pressure-sensitive adhesive composition according to [1] or [2] above, wherein the hydroxyl-terminated urethane prepolymer has a content of structural units based on ethylene oxide of 60% by mass or less. [4] A method for producing a pressure-sensitive adhesive composition by mixing a hydroxyl-terminated urethane prepolymer, a solvent, and a healing agent, 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, and the pressure-sensitive adhesive composition has a viscosity of 2500 to 85,000 mPa·s at 25°C. [5] The method for producing a pressure-sensitive adhesive composition according to [4] above, wherein the non-tin-containing catalyst is more than 0.001 parts by mass and less than 0.050 parts by mass relative to 100 parts by mass of the oxyalkylene polymer. [6] The method for producing a pressure-sensitive adhesive composition according to [4] or [5] above, wherein the non-tin-containing catalyst is an organometallic catalyst. [7] The method for producing a pressure-sensitive adhesive composition according to any of [4] to [6] above, wherein the oxyalkylene polymer has an average number of hydroxyl groups per molecule of 1.5 to 3.0. [8] The method for producing a pressure-sensitive adhesive composition according to any of [4] to [7] above, wherein the oxyalkylene polymer comprises an oxyalkylene polymer A having two or more hydroxyl groups per molecule and an oxyalkylene polymer B having one hydroxyl group per molecule. [9] A pressure-sensitive adhesive which is a cured product of the pressure-sensitive adhesive composition according to any of [1] to [3] above.

[10] A patch having a substrate and a pressure-sensitive adhesive layer provided on at least a part of the surface of the substrate, the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive described in [9] above.

[11] A transdermal absorption patch comprising at least one selected from the group consisting of the pressure-sensitive adhesive described in [9] above and the patch described in

[10] above.

[0009] According to the present invention, it is possible to provide an adhesive composition having excellent dispersibility of a healing agent, a method for producing the same, an adhesive, a patch, and an adhesive transdermal absorption patch.

[0010] The present invention will be described in detail below. In this specification, the preferred definitions can be adopted arbitrarily, and combinations of preferred definitions are considered more preferable. In this specification, the term "XX to YY" means "XX or more and YY or less." In this specification, the lower and upper limits of preferred numerical ranges (e.g., ranges of content, etc.) 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 the values ​​shown in the examples. 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]) between the isocyanate group to be reacted and the active hydrogen-containing group (e.g., hydroxyl group), and is expressed as a percentage. For example, an isocyanate index of 85 indicates that the equivalent ratio between the isocyanate group and the active hydrogen-containing group (e.g., hydroxyl group) is 85%. In this specification, the term "solid content" refers to the non-volatile content excluding volatile substances such as solvents, and refers to the components that remain without volatilization when the pressure-sensitive adhesive composition is dried, including those that are liquid, syrup-like, or waxy at room temperature. The total solid content can also be calculated from the charge amount.

[0011] [Adhesive Composition] The adhesive composition of an embodiment of the present invention (hereinafter, sometimes simply referred to as "the present embodiment") is not particularly limited as long as it contains a hydroxyl group-terminated urethane prepolymer, a solvent, and a healing agent, and may or may not contain a polyisocyanate compound, which is a curing agent for the hydroxyl group-terminated urethane prepolymer, other components, etc., as necessary.

[0012] The 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 adhesive strength to the skin, it is preferably 60% by mass or less, more preferably 1 to 55% by mass, even more preferably 2 to 50% by mass, even more preferably 2 to 40% by mass, and particularly preferably 3 to 25% by mass. The EO unit content in the pressure-sensitive adhesive composition is derived from the EO units that constitute 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 composition by C-NMR (nuclear magnetic resonance) measurement.

[0013] The viscosity of the adhesive composition at 25°C is not particularly limited as long as it is 2500 to 85000 mPa·s, but from the viewpoint of improving the dispersibility of the therapeutic agent, it is preferably 3000 to 80000 mPa·s, and from the viewpoint of improving the dispersibility of the therapeutic agent and the coatability and skin adhesion of the cured product of the adhesive composition (adhesive and adhesive layer), it is more preferably 3300 to 75000 mPa·s, and particularly preferably 3500 to 70000 mPa·s. Note that the "viscosity of the adhesive composition at 25°C" here is measured by the same method as in the Examples.

[0014] The solids content of the pressure-sensitive adhesive composition is not particularly limited, but from the viewpoint of ease of synthesis of the hydroxyl group-terminated urethane prepolymer, it is preferably 25 to 58 mass%, more preferably 30 to 56 mass%, and particularly preferably 35 to 51 mass%, based on 100 mass% of the pressure-sensitive adhesive composition.

[0015] The content of the hydroxyl group-terminated urethane prepolymer in the PSA composition is not particularly limited, but from the viewpoint of obtaining a PSA that is gentle to the skin and has good adhesive strength to the skin, the content is preferably 20 to 58 mass%, more preferably 25 to 55 mass%, and particularly preferably 30 to 52 mass%, relative to 100 mass% of the PSA composition.

[0016] (Hydroxyl Group-Terminated Urethane Prepolymer) The hydroxyl group-terminated urethane prepolymer is not particularly limited, but may be, for example, a reaction product of an oxyalkylene polymer and a diisocyanate compound in the presence of a tin-free catalyst.

[0017] The EO unit content in the hydroxyl-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 7 to 50% by mass, even more preferably 12 to 40% by mass, and particularly preferably 15 to 25% by mass. By having the EO unit content in the hydroxyl-terminated urethane prepolymer within the above range, it is easy to obtain a PSA that is gentle on the skin and has good adhesion to the skin. The EO unit content in the hydroxyl-terminated urethane prepolymer is a weighted average of the EO unit content in each component of the raw material. Note that, like the EO unit content in the PSA composition, the EO unit content in the hydroxyl-terminated urethane prepolymer is also １３ It can also be determined by C-NMR measurement.

[0018] The content of the structural units based on the oxyalkylene polymer in the hydroxyl group-terminated urethane prepolymer is not particularly limited, but from the viewpoint of obtaining a PSA that is gentle on the skin and has good adhesive strength to the skin, the content is preferably 80.0 to 99.5 mass%, more preferably 85.0 to 99.5 mass%, and particularly preferably 90.0 to 99.5 mass%, based on 100 mass% of the hydroxyl group-terminated urethane prepolymer.

[0019] ((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 5 to 55% by mass, even more preferably 7 to 50% by mass, still more preferably 12 to 40% by mass, and particularly preferably 15 to 25% by mass. The average content of EO units in the oxyalkylene polymer refers to a weighted average value of the EO unit contents in each oxyalkylene polymer based on the blend amounts of multiple oxyalkylene polymers used in the synthesis of the hydroxyl group-terminated urethane prepolymer. The EO unit content in each oxyalkylene polymer is a value calculated based on the EO blend amount of 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, a pressure-sensitive adhesive that is gentle to the skin and has good adhesive strength to the skin is easily obtained.

[0020] 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 a weighted average value 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 type of oxyalkylene polymer or two or more types of oxyalkylene polymers.

[0021] The oxyalkylene polymer preferably includes an oxyalkylene polymer A (hereinafter sometimes simply referred to as "polymer A") having two or more hydroxyl groups per molecule, and an oxyalkylene polymer B (hereinafter sometimes simply referred to as "polymer B") having one hydroxyl group per molecule. It is preferred that the hydroxyl groups of polymer A and polymer B react with the isocyanate groups of the diisocyanate compound to form urethane bonds, and that the unreacted hydroxyl groups are terminal hydroxyl groups of the molecular chain of the hydroxyl-terminated urethane prepolymer.

[0022] 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 to polymer B in the oxyalkylene polymer is not particularly limited, but from the viewpoint of obtaining a pressure-sensitive adhesive agent having good adhesive strength to skin, the mass ratio is preferably 10 / 90 to 95 / 5, more preferably 30 / 70 to 90 / 10, even more preferably 50 / 50 to 90 / 10, and particularly preferably 60 / 40 to 90 / 10.

[0023] -Oxyalkylene Polymer A- Polymer A has two or more hydroxyl groups per molecule, preferably two to six. Polymer A may be one type of oxyalkylene polymer, or two or more types of oxyalkylene polymers. When polymer A is composed of two or more types of oxyalkylene polymers, the adhesive strength of the resulting adhesive can be easily adjusted. When polymer A is composed of two or more types 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 polymer A is within the above range, an adhesive that reduces stress on the skin and 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 using the formula: hydroxyl value × Mn / 56100. The hydroxyl value can be measured by the method described in the Examples. Alternatively, a commercially available product can be used as polymer A. Commercially available products of polymer A are not particularly limited, and examples thereof 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" (both manufactured by Covestro);

[0024] When polymer A is composed of two or more oxyalkylene polymers, examples of polymer A include 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 a single type or two or more types. Similarly, polymer A2 may be a single type or two or more types. Polymer A may contain an oxyalkylene polymer having four or more hydroxyl groups per molecule. When polymer A is composed of polymer A1 and polymer A2, the weighted average value based on the composition ratio (blending amount) of polymer A1 and polymer A2, where polymer A1 has three hydroxyl groups per molecule and polymer A2 has two hydroxyl groups per molecule, can be considered to be the average number of hydroxyl groups of polymer A.

[0025] The total amount of polymer A1 and polymer A2 in 100 parts by mass of polymer A is not particularly limited, but is preferably 85 parts by mass or more, more preferably 90 parts by mass or more, and even more preferably 95 parts by mass or more, from the viewpoint of ease of adjusting the adhesive strength of the resulting pressure-sensitive adhesive, etc. It is particularly preferred that the total amount of polymer A1 and polymer A2 in 100 parts by mass of polymer A is 100 parts by mass, i.e., polymer A consists of polymer A1 and polymer A2.

[0026] The content of polymer A1 is not particularly limited, but from the viewpoint of the adhesive strength of the resulting PSA and the suppression of 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. For example, when polymer A consists of polymer A1 and polymer A2, the content of polymer A2 is not particularly limited, but from the viewpoint of the adhesive strength of the PSA and the suppression of adhesive residue, it is preferably 10 parts by mass or more, more preferably 10 to 300 parts by mass, and particularly preferably 50 to 200 parts by mass, per 100 parts by mass of polymer A1.

[0027] 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, even more preferably 0 to 60% by mass, and particularly preferably 0 to 50% by mass. １３ The monomer composition of the oxyalkylene chain in polymer A can be analyzed and determined by C-NMR measurement. For example, when the oxyalkylene chain in polymer A is composed of EO units and PO units, the EO unit content can be calculated based on the area of ​​the peak representing the methylene group of the EO unit and the area of ​​the peak representing the methyl group of the PO unit. When polymer A is composed of, for example, polymer A1 and polymer A2, the EO unit contents of polymer A1 and polymer A2 are similar. The average EO unit content in polymer A can be considered to be a value calculated from the amount of EO blended in the synthetic raw materials for polymer A. When polymer A is composed of, for example, 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 (blending amounts) of polymer A1 and polymer A2.

[0028] The Mn of polymer A is not particularly limited, but from the viewpoints of achieving good adhesive strength of the resulting pressure-sensitive adhesive, suppressing adhesive residue, and forming a pressure-sensitive 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. The Mw / Mn (molecular weight distribution) of polymer A is not particularly limited, but from the viewpoints of achieving a ratio close to 1 and a narrow molecular weight distribution, which makes it difficult for the hydroxyl-terminated urethane prepolymer to become highly viscous and improves synthesis efficiency, it is preferably 1.25 or less, more preferably 1.22 or less, and particularly preferably 1.20 or less. The unsaturation degree of polymer A is also not particularly limited, but from the viewpoints of achieving good curing properties of the hydroxyl-terminated urethane prepolymer and suppressing adhesive residue of the resulting pressure-sensitive adhesive, it is preferable that it is closer to 0 meq / g, 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 oxyalkylene polymers, it is preferable that each oxyalkylene polymer has Mn, Mw / Mn and degree of unsaturation within the above ranges. The degree of unsaturation can be measured by the method described in the Examples.

[0029] The synthesis method of polymer A is not particularly limited, and for example, it 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, thereby simultaneously producing polymer A1 and polymer A2. From the viewpoint 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.

[0030] 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.

[0031] 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.

[0032] Examples of groups having active hydrogen in the initiator include hydroxyl groups, carboxyl groups, and amino groups having a hydrogen atom bonded to a nitrogen atom. These may be used alone, or two or more may be used in combination. Among these, hydroxyl groups are preferred, and alcoholic hydroxyl groups are more preferred. Examples of initiators having three hydroxyl groups include glycerin, trimethylolethane, trimethylolpropane, and 1,2,6-hexanetriol. These may be used alone, or two or more may be used in combination. Examples of initiators having two hydroxyl groups include ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol. These may be used alone, or two or more may be used in combination.

[0033] The number of active hydrogens 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 an initiator. Polymer A2 can be synthesized, for example, using propylene glycol as an initiator. The initiators used as raw materials for synthesizing the oxyalkylene polymer are: １３When polymer A is composed of polymer A1 and polymer A2, the type and amount of polymer A can be identified by C-NMR measurement. １３ The ratio of polymer A1 to polymer A2 is 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 the initiator obtained by C-NMR measurement.

[0034] 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 an organoaluminum compound with porphyrin, 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. Synthesis of oxyalkylene polymers by ring-opening addition polymerization using a DMC catalyst can be carried out by known methods, for example, production methods described in WO 2003 / 062301, WO 2004 / 067633, JP 2004-269776 A, JP 2005-15786 A, WO 2013 / 065802, JP 2015-10162 A, etc. can be applied.

[0035] -Oxyalkylene polymer B- The oxyalkylene polymer B has one hydroxyl group per molecule. As the polymer B, one type of oxyalkylene polymer may be used alone, or two or more types of oxyalkylene polymers may be used. The number of hydroxyl groups of the polymer B is, like that of the polymer A, １３ This can be confirmed by identifying the type and amount of the initiator used as a synthesis raw material through C-NMR measurement. Alternatively, a commercially available product can be used as polymer B. There are no particular limitations on the commercially available product of polymer B, and examples thereof include "Preminol S 1011" and "Preminol S 1004F" (manufactured by AGC Inc.).

[0036] The Mn of polymer B is not particularly limited, but from the viewpoints of forming a pressure-sensitive adhesive layer with good flexibility, good adhesive strength of the resulting pressure-sensitive adhesive, and suppression of 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. The Mw / Mn of polymer B is not particularly limited, but from the viewpoints of being close to 1 and having a narrow molecular weight distribution, the hydroxyl-terminated urethane prepolymer is less likely to become highly viscous and synthesis efficiency is improved, it is preferably less than 1.20, more preferably less than 1.13, and particularly preferably less than 1.10. The unsaturation degree of polymer B is also not particularly limited, but from the viewpoints of good curing properties of the hydroxyl-terminated urethane prepolymer and suppression of adhesive residue in the pressure-sensitive adhesive layer formed, it is preferably 0.015 meq / g or less, more preferably 0.013 meq / g or less, 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 oxyalkylene polymers, it is preferable that each oxyalkylene polymer has Mn, Mw / Mn and degree of unsaturation within the above ranges. The degree of unsaturation can be measured by the method described in the Examples.

[0037] The synthesis method of polymer B is not particularly limited, and can be obtained, for example, by ring-opening addition polymerization of a compound having a cyclic ether structure, preferably an alkylene oxide, with 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.

[0038] The average content of EO units in polymer B is not particularly limited, but from the viewpoint of obtaining a PSA having good adhesive strength to skin and suppressed crystallinity, it is preferably 0 to 80 mass%, more preferably 0 to 60 mass%, and particularly preferably 0 to 50 mass%. The average content of EO units in polymer B can be determined in the same manner as for polymer A.

[0039] 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 two or more may be used in combination. Among these, a hydroxyl group is preferred, and an alcoholic hydroxyl group is more preferred. As the initiator having one hydroxyl group, from the viewpoint of ease of availability, for example, monohydric alcohols having 2 to 4 carbon atoms such as n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, and tert-butanol are preferred. These may be used alone, or two or more may be used in combination. 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.

[0040] For example, when polymer A consists of polymer A1 and polymer A2, the content of polymer A1 is not particularly limited, but from the viewpoint of obtaining a pressure-sensitive adhesive having good adhesive strength to skin, it 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 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 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 even more preferably 10 to 20 parts by mass, per 100 parts by mass 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.

[0041] (Diisocyanate Compound) The diisocyanate compound used in the synthesis of the hydroxyl group-terminated urethane prepolymer is an organic compound having two isocyanate groups per molecule. The diisocyanate compound is not particularly limited, and examples thereof include aliphatic diisocyanate compounds, alicyclic diisocyanate compounds, aromatic diisocyanate compounds, and araliphatic diisocyanate compounds. These may be used alone or in combination of two or more.

[0042] The aliphatic diisocyanate compound may be either linear or branched. The aliphatic diisocyanate compound is not particularly limited, and examples thereof include 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(isocyanatomethyl)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 two or more may be used in combination. 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 two or more may be used in combination. 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.

[0043] Furthermore, as the diisocyanate compound, a bifunctional isocyanate-terminated urethane prepolymer obtained by previously reacting the above-mentioned diisocyanate compound with a diol (for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, etc.) can also be used.

[0044] The content of the diisocyanate compound used in the reaction between the oxyalkylene polymer and the diisocyanate compound is not particularly limited, but from the viewpoint of ensuring an appropriate synthesis rate of the hydroxyl group-terminated urethane prepolymer, it is preferably 0.5 to 20.0 parts by mass, more preferably 0.5 to 15.0 parts by mass, even more preferably 0.5 to 10.0 parts by mass, and particularly preferably 0.5 to 5.0 parts by mass, relative to 100 parts by mass of the oxyalkylene polymer.

[0045] ((Tin-free catalyst)) The tin-free catalyst is a urethane-forming catalyst that does not contain tin. From the viewpoint of obtaining a pressure-sensitive adhesive that is low in toxicity and has little effect on the skin, it is preferable that the pressure-sensitive adhesive does not contain tin or tin compounds.

[0046] 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 viewpoint of low toxicity to the skin, ease of handling, etc.

[0047] The tertiary amine catalyst is not particularly limited, and examples thereof include triethylamine, triethylenediamine, 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), and the like. These may be used alone, or two or more types may be used in combination. The organometallic catalyst containing a metal other than tin is not particularly limited, and examples thereof include zinc carboxylates such as zinc naphthenate and zinc 2-ethylhexanoate, zinc compounds such as zinc acetylacetonate, and the like; bismuth compounds such as bismuth 2-ethylhexanoate and bismuth neodecanoate, and the like; titanium compounds such as dibutyltitanium dichloride, tetrabutyltitanium, and butoxytitanium trichloride, and the like; lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate, and the like; iron compounds such as iron 2-ethylhexanoate and iron acetylacetonate, and the like; cobalt compounds such as cobalt benzoate and cobalt 2-ethylhexanoate, and the like; and zirconium compounds such as zirconium naphthenate. These may be used alone or in combination of two or more.

[0048] 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 a good reaction-accelerating effect and a reduction in the amount of residual metal components, the amount is preferably more than 0.001 part by mass and less than 0.050 part by mass, more preferably 0.003 to 0.048 parts by mass, even more preferably 0.005 to 0.045 parts by mass, and particularly preferably 0.010 to 0.040 parts by mass, relative to 100 parts by mass of the oxyalkylene polymer.

[0049] (Solvent) The solvent contained in the pressure-sensitive adhesive composition of the present embodiment is not particularly limited and can be selected from the viewpoints of the solubility of the components contained therein and the dispersibility of the healing agent, etc. Examples include ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; ethers such as propylene glycol monomethyl ether; amides such as N,N-dimethylformamide; aromatic hydrocarbons such as toluene and xylene; and the like. These may be used alone or in combination of two or more. Among these, from the viewpoints of the solubility and coatability of the hydroxyl-terminated urethane prepolymer, preferably at least one selected from the group consisting of esters and aromatic hydrocarbons, more preferably at least one selected from the group consisting of ethyl acetate and toluene. Note that the solvent contained in the pressure-sensitive adhesive composition of the present embodiment may be the same as the solvent used in the production of the hydroxyl-terminated urethane prepolymer described below.

[0050] The timing of adding the solvent contained in the pressure-sensitive adhesive composition of the present embodiment is not particularly limited, as long as the pressure-sensitive adhesive composition contains a solvent. Examples include (1) adding the solvent to a mixture of a hydroxyl-terminated urethane prepolymer and a healing agent, (2) adding the solvent to the hydroxyl-terminated urethane prepolymer before adding the healing agent, and (3) adding the solvent at the stage of synthesizing the hydroxyl-terminated urethane prepolymer.

[0051] The content of the solvent contained in the pressure-sensitive adhesive composition of the present embodiment is not particularly limited, but from the viewpoint of keeping the viscosity of the pressure-sensitive adhesive composition of the present embodiment within a suitable range, the content is preferably 40 to 75 mass %, more preferably 42 to 70 mass %, and particularly preferably 43 to 68 mass %, relative to 100 mass % of the pressure-sensitive adhesive composition.

[0052] (Healing Drug) The healing drug contained in the adhesive composition of the present embodiment is not particularly limited, and examples thereof include: therapeutic drugs for angina pectoris such as nitroglycerin; therapeutic drugs for urinary incontinence such as oxybutynin; neurostimulants such as methylphenidate; contraceptives such as estradiol, testosterone, progestin, progesterone, levonorgestrel; therapeutic drugs for heart failure such as digitalis and digoxin; analgesics such as fentanyl, lidocaine, diclofenac, flurbiprofen, morphine, and fentanyl; cosmetics such as menthol, vitamin E, and aromatic oils; gastric antipersistance drugs such as (-)-menthol; antiemetics such as scopalamine; anti-smoking drugs such as nicotine; steroidal anti-inflammatory drugs such as hydrocortisone, prednisolone, and triamcinolone; non-steroidal anti-inflammatory drugs such as naproxen and piroxicam; antibiotics such as penicillin antibiotics, cephalosporin antibiotics, and quinolone antibiotics; antiprotozoal drugs such as metronidazole; antifungal drugs such as nystatin; calcium channel blockers such as nifedipine and diltiazem; Bronchodilators such as filin, pirbuterol, salmeterol, isoproterenol, etc.; enzyme inhibitors such as collagenase inhibitors, protease inhibitors, elastase inhibitors, lipoxygenase inhibitors, angiotensin-converting enzyme inhibitors, etc.; antihypertensives such as propranolol; leukotriene antagonists; antiulcer drugs; antiviral drugs; immunomodulators; anesthetics such as benzocaine and propofol; antitussives such as codeine and dextromethorphan; antihistamines such as diphenhydramine, chlorpheniramine, and terfenadine. Examples of the anticoagulant include antiseptics; anticonvulsants such as carbamazepine; immunosuppressants such as cyclosporine; antianxiety drugs such as diazepam; sedatives such as phenobarbital; anticoagulants such as heparin; analgesics such as acetaminophen; antimigraine drugs such as ergotamine, melatonin, and sumatriptan; antiarrhythmic drugs such as flecainide; antiemetics such as metaclopromide and ondansetron; anticancer drugs such as methotrexate; hemostatic drugs; antiobesity drugs; pharmaceutically acceptable salts, ester derivatives, solvates, and clathrates thereof. These may be used alone or in combination of two or more. The adhesive composition of this embodiment may also contain veterinary medicines and agricultural and horticultural medicines in addition to the above-mentioned healing drugs.Transdermal administration of a cured adhesive composition containing a veterinary or agricultural or horticultural drug allows for more accurate dosing than administration via food (oral administration) / perfusion water.

[0053] The healing agent may be soluble, slightly soluble, or insoluble in the solvent contained in the pressure-sensitive adhesive composition.

[0054] The content of the healing agent contained in the pressure-sensitive adhesive composition of this embodiment is not particularly limited, but from the viewpoint of solubility and dispersibility in the pressure-sensitive adhesive liquid, it is preferably 20 parts by mass or less, more preferably 0.1 to 15 parts by mass, and particularly preferably 0.5 to 10 parts by mass, per 100 parts by mass of the pressure-sensitive adhesive composition. The content of the healing agent contained in the pressure-sensitive adhesive composition of this embodiment is not particularly limited, but from the viewpoint of solubility and dispersibility in the pressure-sensitive adhesive liquid, it is preferably 20 parts by mass or less, more preferably 0.1 to 15 parts by mass, and particularly preferably 0.5 to 10 parts by mass, per 100 parts by mass of the hydroxyl group-terminated urethane prepolymer.

[0055] (Polyisocyanate Compound) The polyisocyanate compound is an optional component and is a curing agent for the hydroxyl group-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. As the polyisocyanate compound, from the viewpoints of availability and reactivity, a diisocyanate compound is preferred, and from the viewpoints of good adhesive strength of the resulting pressure-sensitive adhesive and suppression of adhesive residue, a polyisocyanate compound having three or more isocyanate groups in one molecule is preferred.

[0056] Specific examples of diisocyanate compounds include the same as the specific examples of diisocyanate compounds constituting the above-mentioned hydroxyl group-terminated urethane prepolymer. These may be used alone, or two or more may be used in combination. Examples of polyisocyanate compounds having three or more isocyanate groups per molecule include isocyanurate-modified compounds, biuret-modified compounds, and allophanate-modified compounds, which are derivatives of the above-mentioned diisocyanate compounds, as well as trifunctional or higher isocyanate group-terminated urethane prepolymers (adducts), which are reaction products of diisocyanate compounds and polyols (e.g., trimethylolpropane) having three or more hydroxyl groups per molecule. These may be used alone, or two or more may be used in combination.

[0057] 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 93 mass%.

[0058] 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 7 to 30 mass%.

[0059] (Other Components) The pressure-sensitive adhesive composition may contain other components in addition to the hydroxyl-terminated urethane prepolymer, solvent, healing agent, and polyisocyanate compound. Examples of other components include various additives such as plasticizers, antioxidants, antistatic agents, fillers, UV absorbers, light stabilizers, conductivity-imparting agents, and leveling agents. These may be used alone or in combination of two or more, and may be blended in a content range that does not impair the effects of the present invention. The total content of the hydroxyl-terminated urethane prepolymer, solvent, and healing agent in the pressure-sensitive adhesive composition 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 particularly preferably 100% by mass.

[0060] The plasticizer is not particularly limited, but can be selected from the viewpoints of compatibility with other components and wettability of the pressure-sensitive adhesive layer to the adherend. Examples 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 include phenol-based, amine-based, sulfur-based, and phosphorus-based antioxidants that contribute to suppressing thermal degradation of the pressure-sensitive 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 include inorganic salts; ionic liquids containing imidazolium ions, pyridinium ions, ammonium ions, etc.; surfactants; and other compounds that contribute to suppressing damage to circuit patterns due to electrostatic discharge. These may be used alone or in combination of two or more. The filler is not particularly limited, and examples 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, and triazine-based ultraviolet absorbers. 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-based 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 metal microparticles such as silver nanoparticles. These may be used alone or in combination of two or more. The leveling agent is not particularly limited, and examples thereof include polymer-based leveling agents such as acrylic, vinyl, silicone, and fluorine-based. These may be used alone or in combination of two or more.

[0061] [Method for Producing a Pressure-Sensitive Adhesive Composition] The method for producing a pressure-sensitive adhesive composition of this embodiment involves mixing a hydroxyl-terminated urethane prepolymer, a solvent, and a healing agent to produce a pressure-sensitive adhesive composition, 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, and the pressure-sensitive adhesive composition has a viscosity of 2,500 to 85,000 mPa·s at 25°C. The pressure-sensitive adhesive composition thus obtained is reacted with a polyisocyanate compound to produce the pressure-sensitive adhesive and patch described below. Note that when mixing the hydroxyl-terminated urethane prepolymer and the polyisocyanate compound, other components that may be contained in the pressure-sensitive adhesive composition described above may also be mixed.

[0062] (Method for producing hydroxyl-terminated urethane prepolymer) The hydroxyl-terminated urethane prepolymer used in the method for producing the pressure-sensitive adhesive composition of this embodiment is not particularly limited, and may be, for example, a reaction product of an oxyalkylene polymer and a diisocyanate compound in the presence of a tin-free catalyst. The method for producing the hydroxyl-terminated urethane prepolymer is not particularly limited, and examples 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; or a method in which a diisocyanate compound is added dropwise or the like to a reaction vessel charged with an oxyalkylene polymer, a catalyst, and a solvent. As a method for producing the hydroxyl-terminated urethane prepolymer, a method in which a diisocyanate compound is added later is preferred from the viewpoint of easy 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.

[0063] The tin-free catalyst used in the production of the hydroxyl-terminated urethane prepolymer can be the same compound as described above. The preferred content of the tin-free catalyst can be determined from the above. The amount of the tin-free catalyst is not particularly limited, but from the viewpoint of achieving a good reaction-promoting effect and reducing the amount of residual metal components, the amount is preferably more than 0.001 parts by mass and less than 0.050 parts by mass, more preferably 0.003 to 0.048 parts by mass, even more preferably 0.005 to 0.045 parts by mass, and particularly preferably 0.010 to 0.040 parts by mass, relative to 100 parts by mass of the oxyalkylene polymer.

[0064] The oxyalkylene polymer and diisocyanate compound used in the production of the hydroxyl group-terminated urethane prepolymer can be the same as those described above, and the preferred quantitative ratios are also the same as those described above. The oxyalkylene polymer preferably contains the polymer A and the polymer B, and the polymer A preferably contains the polymer A1 and the polymer A2. These polymers can be the same as those described above, and the preferred quantitative ratios are also the same as those described above.

[0065] The solvent used in the production of the hydroxyl-terminated urethane prepolymer is not particularly limited, and examples thereof include ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; and aromatic hydrocarbons such as toluene and xylene. These may be used alone or in combination of two or more. When a solvent is used in the production of the hydroxyl-terminated urethane prepolymer, there are no particular limitations on the amount used, but from the viewpoints of 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.

[0066] 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 having an appropriate molecular chain length, it is preferably less than 100, more preferably 30 to 95, and particularly preferably 50 to 95.

[0067] The reaction temperature in the production of the hydroxyl-terminated urethane prepolymer is not particularly limited, but from the viewpoint of promoting the urethanization 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. The reaction time in the production of the hydroxyl-terminated urethane prepolymer is not particularly limited, but from the viewpoint of promoting the urethanization reaction and suppressing side reactions, it is preferably 3 to 10 hours, more preferably 5 to 9 hours. After completion of the reaction, a reaction terminator such as acetylacetone may be added to deactivate the catalyst.

[0068] The average number of hydroxyl groups per molecule of the hydroxyl-terminated urethane prepolymer is not particularly limited, but from the viewpoint of obtaining a pressure-sensitive 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.

[0069] [Adhesive] The adhesive of this embodiment is a cured product of the adhesive composition of this embodiment described above. The adhesive is obtained as a reaction product between a hydroxyl group-terminated urethane prepolymer in the adhesive composition and a polyisocyanate compound. As described below, for example, the adhesive can be formed as an adhesive layer by applying the adhesive composition to a substrate and curing it. The adhesive obtained by curing the adhesive composition of this embodiment has excellent dispersibility of healing agents, good adhesive strength to the skin, and is less likely to leave adhesive residue, making it suitable for application to the skin.

[0070] Depending on the manner of use of the pressure-sensitive adhesive, the pressure-sensitive adhesive composition may be a one-component type in which a hydroxyl group-terminated urethane prepolymer and a polyisocyanate compound as a curing agent are pre-mixed, or may be a two-component type consisting of a first part containing a hydroxyl group-terminated urethane prepolymer and a second part containing a polyisocyanate compound as a curing agent.

[0071] In the reaction between the hydroxyl-terminated urethane prepolymer and the polyisocyanate compound, a catalyst and a solvent may or may not be used, as 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 may also catalyze the reaction between the hydroxyl-terminated urethane prepolymer and the polyisocyanate compound. When a catalyst is added during the reaction between the hydroxyl-terminated urethane prepolymer and the polyisocyanate compound, there are no particular restrictions on the amount of catalyst added. However, from the viewpoint of promoting the reaction well and reducing the amount of residual metal components in the composition, the amount of catalyst added is preferably more than 0.001 part by mass and less than 0.050 part by mass, more preferably 0.005 to 0.045 parts by mass, and particularly preferably 0.010 to 0.040 parts by mass, per 100 parts by mass of the combined 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 the reaction to deactivate the catalyst.

[0072] 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.

[0073] 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 urethanization 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.

[0074] 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.

[0075] The temperature at which the pressure-sensitive adhesive composition is cured is not particularly limited, but from the viewpoint of sufficiently volatilizing the solvent contained in the pressure-sensitive adhesive composition, it is preferable to dry the composition with hot air at 40 to 80°C.

[0076] [Patch] The patch of the present embodiment has a substrate and a pressure-sensitive adhesive layer provided on at least a part of the surface of the substrate, and the pressure-sensitive adhesive layer contains the pressure-sensitive adhesive of the present embodiment described above. A patch having a pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition of the present embodiment has excellent dispersibility of a healing drug, and the pressure-sensitive adhesive layer has good adhesive strength to the skin and is less likely to leave adhesive residue, making it suitable for application to the skin.

[0077] The patch may be in the form of a sheet of a desired size depending on the mode of use, or may be cut to a desired size for use. From the viewpoint of convenience, the patch is preferably an adhesive tape.

[0078] The pressure-sensitive adhesive composition used to form the pressure-sensitive adhesive layer may be a one-component type in which a hydroxyl-terminated urethane prepolymer and a polyisocyanate compound as a curing agent are pre-mixed, depending on the mode of use of the patch, or may be 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.

[0079] 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 20 to 50 μm.

[0080] (Substrate) The substrate is preferably made of a material that has good conformability to the skin and device shape of the patch and is unlikely to break during use of the patch, and examples thereof include resin films, cloths, paper, etc. These may be used alone, in combination of two or more types, or as a composite material formed by lamination or the like. The material for the resin film is not particularly limited, and examples thereof include polyurethane; polyamide; acrylic resin; polyolefins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer; polyester, etc. These may be used alone, or in combination of two or more types. Of these, from the viewpoint of good moisture permeability when applied to the skin, polyurethane and polyamide are preferred, and thermoplastic polyurethane is more preferred. The cloth is not particularly limited, and examples thereof include woven fabrics, nonwoven fabrics, knitted fabrics, nets, etc., and examples of materials include the resins used for the resin films described above, as well as natural fibers such as cotton, silk, and wool. These may be used alone, or in combination of two or more types.

[0081] The substrate may or may not include an auxiliary layer. The auxiliary layer is not particularly limited, and examples thereof include a colored layer, an undercoat layer, an antistatic layer, and the like provided on the surface of the substrate.

[0082] The surface of the substrate is not particularly limited, but from the viewpoint of improving adhesion and retention with the pressure-sensitive adhesive layer, it may or may not be subjected to surface treatments 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, chemical treatments such as chromic acid treatment, and adhesion-enhancing treatment using a coating agent (primer). The surface treatment for improving adhesion is preferably applied to the entire surface of the substrate layer.

[0083] The thickness of the substrate is not particularly limited, but from the viewpoints of ensuring conformability to the shape of the skin and the device and making the substrate less likely to break when the patch is used, it is preferably 1 to 500 μm, more preferably 5 to 100 μm, and particularly preferably 10 to 30 μm.

[0084] (Adhesive Layer) The surface of the adhesive layer of the patch is not particularly limited, but is preferably covered with a release liner from the viewpoint of protecting the surface of the adhesive layer before use of the patch. The release liner is appropriately peeled off from the surface of the adhesive layer when the patch is used. Examples of release liners that can be used in known adhesive tapes for skin include high-quality paper coated with a release agent such as silicone resin or fluororesin; glassine paper; parchment paper; resin anchor coated or polyethylene-laminated high-quality paper coated with a release agent such as silicone resin or fluororesin; and transparent resin films such as polyester films. These may be used alone or in combination of two or more. The thickness of the release liner is not particularly limited, but is preferably 5 to 200 μm, more preferably 10 to 100 μm, and particularly preferably 20 to 50 μm, from the viewpoint of protecting the adhesive layer and releasability during use.

[0085] The pressure-sensitive adhesive layer may be provided, for example, in one or more locations on a portion of the surface of the resin film substrate, on only a portion of one side, or on the entire surface of one side, or on both sides of the surface of the substrate.

[0086] The adhesive strength of the adhesive layer to the skin is not particularly limited, but from the viewpoint of obtaining good adhesive strength to the skin and little adhesive residue, it is preferably 1.0 to less than 3.0 N / 15 mm. The adhesive strength referred to here is measured by a method in accordance with JIS Z 0237:2009.

[0087] The content of the pressure-sensitive adhesive of this embodiment in the pressure-sensitive adhesive layer is not particularly limited, but from the viewpoint of fully exerting the effects of the present invention, it is preferably 50% by mass or more, more preferably 65% ​​by mass or more, even more preferably 90% by mass or more, and particularly preferably 100% by mass, of 100% by mass of the pressure-sensitive adhesive layer.

[0088] The adhesive patch can be produced using any known method without any particular limitations. Examples include a method of applying a pressure-sensitive adhesive composition to a release liner, curing the composition to form a pressure-sensitive adhesive layer, and laminating a substrate; a method of applying a pressure-sensitive adhesive composition to a substrate, curing the composition to form a pressure-sensitive adhesive layer, and laminating a release liner; and the like. These methods may be used alone, or two or more types may be used in combination. The method for applying the pressure-sensitive adhesive composition is also not particularly limited, and known methods such as bar coating, knife coating, roll coating, blade coating, die coating, microgravure coating, comma coating, slot die coating, lip coating, and cast coating can be used. These methods may be used alone, or two or more types may be used in combination. After application, the pressure-sensitive adhesive composition is preferably cured by, for example, hot air drying at 40 to 80°C to sufficiently volatilize the solvent contained in the pressure-sensitive adhesive composition, thereby forming a pressure-sensitive adhesive layer.

[0089] [Transdermal absorption patch] The transdermal absorption patch of this embodiment only needs to contain at least one selected from the group consisting of the adhesive of this embodiment and the patch of this embodiment, and may or may not have a substrate on the side opposite to the adhesive surface that is applied to the skin. The transdermal absorption patch of this embodiment, which contains at least one selected from the group consisting of the adhesive of this embodiment and the patch of this embodiment described above, has excellent dispersibility of the therapeutic agent, and the adhesive layer has good adhesion to the skin, is less likely to leave adhesive residue, making it suitable for application to the skin. The transdermal absorption patch of this embodiment may be configured to have an adhesive layer in advance, or may be configured to have the adhesive or patch as a separate component so that the adhesive layer can be formed during use.

[0090] The substrate of the transdermal absorption patch may be the same as the substrate of the adhesive patch.

[0091] The transdermal absorption patch may be in the form of a sheet of a desired size depending on the mode of use and the amount of therapeutic drug, or may be cut to the desired size for use.

[0092] There are no particular restrictions on the thickness of the transdermal absorption patch, but from the viewpoint of reducing discomfort when applied to the skin, it is preferably 20 to 200 μm, more preferably 25 to 180 μm, and particularly preferably 30 to 150 μm.

[0093] 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 gist of the present invention.

[0094] [Measurement Methods in Synthesis Examples] The methods for measuring various physical properties in the following synthesis examples are as follows.

[0095] <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] - Instrument 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°C - Eluent: Tetrahydrofuran - Flow rate: 0.350 mL / min - Sample concentration: 0.5% by mass - Sample injection amount: 10 μL - Standard sample: Polystyrene

[0096] <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, and the amount of EO charged was considered to be the EO unit content in the oxyalkylene polymer. The EO unit content of the hydroxyl group-terminated urethane prepolymer was determined as the weighted average of the EO unit contents in each of the raw material components.

[0097] <Hydroxyl Value> The hydroxyl value was determined in accordance with Method B (automatic potentiometric titration) of JIS K 1557-1:2007.

[0098] <Degree of Unsaturation> The degree of unsaturation was measured in accordance with JIS K 1557-3:2007.

[0099] <Average number of hydroxyl groups per molecule of oxyalkylene polymer A> The average number of hydroxyl groups per molecule of oxyalkylene polymer A was determined by calculating the weighted average of the numbers of hydroxyl groups per molecule of oxyalkylene polymers A1 and A2 used as oxyalkylene polymer A (the number of hydroxyl groups per molecule of the initiator used in the synthesis of each oxyalkylene polymer) based on the blending amount of each oxyalkylene polymer.

[0100] <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 regarded as the average number of hydroxyl groups per molecule of the hydroxyl-terminated urethane prepolymer.

[0101] [Materials Used] Details of the materials used in the following synthesis examples and examples are shown below. TBA-DMC catalyst: zinc hexacyanocobaltate complex having 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-based polyisocyanate, solid content approximately 80% by mass "Duranate E402-80B", manufactured by Asahi Kasei Corporation. Healing agent 1: Vitamin C, manufactured by Tokyo Chemical Industry Co., Ltd. Healing agent 2: (-)-Menthol, manufactured by Tokyo Chemical Industry Co., Ltd.

[0102] [Synthesis of Oxyalkylene Polymer] (Synthesis Example 1-1) 1000 g of glycerin as an initiator and a TBA-DMC catalyst (metal concentration 46 ppm by mass) were placed in a pressure vessel, and the vessel was purged with nitrogen. The reaction solution was heated to 135°C while stirring, and 120 g of propylene oxide (PO) was added and reacted. After the temperature rise of the reaction solution stopped, it was cooled to 135°C, and while stirring the reaction solution, 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, and neutralization and catalyst removal were performed to obtain oxyalkylene polymer 1-1, which is polymer A1.

[0103] Synthesis Example 1-2 Oxyalkylene polymer 1-2, which was 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.

[0104] Synthesis Example 1-3 Oxyalkylene polymer 1-3, which was 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 in Synthesis Example 1-1 was added as PO.

[0105] Synthesis Example 1-4 Oxyalkylene polymer 1-4, which was 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 in Synthesis Example 1-2 was added as PO.

[0106] 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 the initiator in Synthesis Example 1-1 was changed from glycerin to n-butanol, and after cooling the reaction solution, 2364 g of PO was added instead of EO. Table 1 shows various physical properties of oxyalkylene polymers 1-1 to 1-5.

[0107]

[0108] [Synthesis of Hydroxyl-Terminated Urethane Prepolymer] (Synthesis Example 2-1-1) 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 were charged into a reaction vessel equipped with a thermometer, a stirrer, and a cooling tube, and 0.038 parts by mass of a urethanization catalyst was added. After mixing at 40 ° C., 1.7 parts by mass of a diisocyanate compound (isocyanate index 85) was added. 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 kept at 80°C while being appropriately diluted with ethyl acetate for dilution, and reacted for 7 hours to obtain a transparent solution of hydroxyl-terminated urethane prepolymer U1-1 (average number of hydroxyl groups per molecule of oxyalkylene polymer (oxyalkylene polymers A1, A2, and B) 2.2, EO unit content 17% by mass) having a hydroxyl-terminated urethane prepolymer solids content of 50% by mass.

[0109] Synthesis Examples 2-1-2 to 2-1-7 Hydroxyl-terminated urethane prepolymer solutions U1-2 to U1-7 were synthesized in the same manner as in Synthesis Example 2-1-1, except that the amount of ethyl acetate added for dilution in Synthesis Example 2-1-1 was adjusted to obtain hydroxyl-terminated urethane prepolymer solutions having the solid contents of hydroxyl-terminated urethane prepolymers shown in Table 2.

[0110] A solution of hydroxyl-terminated urethane prepolymer U2 was synthesized in the same manner as in Synthesis Example 2-1, except that the reaction time was changed from 7 hours to 9 hours. 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 17% by mass.

[0111] Synthesis Example 2-3 A solution of hydroxyl-terminated urethane prepolymer U3 was synthesized in the same manner as in Synthesis Example 2-1, except that the reaction time was changed from 7 hours to 3 hours. The average number of hydroxyl groups per molecule of the oxyalkylene polymers (oxyalkylene polymers A1, A2, and B) of hydroxyl-terminated urethane prepolymer U3 was 2.2, and the EO unit content was 17% by mass.

[0112] Synthesis Example 2-4 A solution of hydroxyl-terminated urethane prepolymer U4 was synthesized 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 U4 was 2.2, and the EO unit content was 7% by mass.

[0113] Synthesis Example 2-5 A solution of hydroxyl-terminated urethane prepolymer U5 was synthesized in the same manner as in Synthesis Example 2-1, except that the reaction time was changed from 7 hours to 11 hours. The oxyalkylene polymers (oxyalkylene polymers A1, A2, and B) of the hydroxyl-terminated urethane prepolymer U5 had an average number of hydroxyl groups per molecule of 2.2 and an EO unit content of 17% by mass.

[0114] Synthesis Example 2-6 A solution of hydroxyl-terminated urethane prepolymer U6 was synthesized in the same manner as in Synthesis Example 2-1, except that the reaction time in Synthesis Example 2-1 was changed from 7 hours to 10 hours. The average number of hydroxyl groups per molecule of the oxyalkylene polymer (oxyalkylene polymers A1, A2, and B) of hydroxyl-terminated urethane prepolymer U6 was 2.2, and the EO unit content was 17% by mass. Table 2 shows the blending compositions of the oxyalkylene polymer, diisocyanate compound, and urethanization catalyst, as well as various physical properties, in Synthesis Examples 2-1-1 to 2-1-7 and Synthesis Examples 2-2 to 2-6.

[0115]

[0116] [Preparation of Pressure-Sensitive Adhesive Compositions] (Examples 1 to 24) The components and amounts (parts by mass) shown in Table 3 were mixed and kneaded in a kneader at room temperature for 10 minutes to obtain pressure-sensitive adhesive compositions of Examples 1 to 24.

[0117] <Viscosity measurement of pressure-sensitive adhesive composition> The viscosity of each pressure-sensitive adhesive composition produced in the above examples was measured using an E-type viscometer at a measurement temperature of 25° C. Note that for Examples 13 and 14, the reaction solution containing various oxyalkylene polymers, toluene, ethyl acetate, urethane-forming catalyst, and diisocyanate compound gelled during the synthesis of the hydroxyl group-terminated urethane prepolymer, and as a result, a pressure-sensitive adhesive composition could not be obtained, and therefore measurement was not possible (n.d.).

[0118] [Evaluation of Pressure-Sensitive Adhesive Compositions] The following various evaluations were carried out for each of the pressure-sensitive adhesive compositions produced in the above examples. The evaluation results are shown in Table 3. Examples 1 to 10, 15 to 20, and 23 to 24 are working examples, while Examples 11 to 14 and 21 to 22 are comparative examples. Note that for Examples 13 and 14, the pressure-sensitive adhesive compositions gelled, so evaluation was deemed ineligible (nd).

[0119] <Dispersibility of healing agent> The dispersibility of the healing agent in each adhesive composition produced in the above examples was visually confirmed. [Evaluation criteria] A: Dispersed and dissolved without any problems B: Dispersed and dissolved, although it took some time C: Poor dispersion (aggregation, localization, etc.) In the cases of ratings A to B, it can be said that the dispersibility is excellent. On the other hand, in the case of rating C, it cannot be said that the dispersibility is excellent.

[0120] <Coatability> 100 parts by mass of the hydroxyl-terminated urethane prepolymer solution in each of the pressure-sensitive adhesive compositions prepared in the above examples was mixed with 5 parts by mass of a curing agent (polyisocyanate compound). The pressure-sensitive adhesive composition was then degassed and applied to a polyester film (38 μm thick) release liner using a knife coater. The composition was then dried at 100°C for 2 minutes to form a pressure-sensitive adhesive layer with a thickness of 5 to 100 μm. The pressure-sensitive adhesive layer was then cured in a hot air dryer at 40°C for 3 days. The thickness of the pressure-sensitive adhesive layer was evaluated according to the following criteria. [Evaluation Criteria] A: 5 to 100 μm B: 5 μm or more but less than 30 μm C: 30 to 100 μm D: Coating defects (streaks, air bubbles, difficulty in controlling film thickness, etc.) observed. A rating of A indicates particularly excellent coatability, as a wide range of thicknesses is possible. Furthermore, even in cases B and C, coatability is sufficiently excellent. On the other hand, in the case of evaluation D, it cannot be said that the coating properties are excellent.

[0121] <Adhesion to Skin> The adhesive layer (the side not coated with a release liner) prepared during the evaluation of coating properties was placed on the skin of the forearm of three humans (test subjects), and the adhesive layer was pressed against a phenolic resin plate by a rubber roller, moving back and forth once at a load of 2 kg and a speed of 300 mm / min, from the side opposite the adhesive layer (the side not coated with a release liner) (the side coated with a release liner). After leaving the adhesive layer to stand for 20 minutes, the adhesive layer was peeled off at a peel angle of 90° and a speed of 300 mm / min, and the adhesive strength of the adhesive layer to the skin was measured according to a method in accordance with JIS Z 0237:2009. The humans (three test subjects) were: (1) Gender: male, Race: Japanese, Age: 30s, (2) Gender: male, Race: Japanese, Age: 20s, and (3) Gender: female, Race: Japanese, Age: 30s. The measured adhesive strength was evaluated according to the following evaluation criteria. [Evaluation criteria (against skin)] A: 1.0 to 3.0 N / 15 mm B: More than 3.0 N / 15 mm C: Less than 1.0 N / 15 mm In the case of evaluation A, it can be said that the adhesive strength to the skin is appropriate. On the other hand, in the case of evaluation B, it was difficult to peel off from the skin, causing pain when peeling, and there was adhesive residue. In addition, in the case of evaluation C, the adhesive strength to the skin was insufficient, and the adhesive layer broke immediately.

[0122]

[0123] As can be seen from the evaluation results shown in Table 3, the pressure-sensitive adhesive compositions of the present invention (Examples 1 to 10, 15 to 20, and 23 to 24) were found to have superior dispersibility of healing agents compared to pressure-sensitive adhesive compositions not of the present invention (Examples 11 to 14, and 21 to 22). In addition, the pressure-sensitive adhesives obtained by curing the pressure-sensitive adhesive compositions of the present invention (Examples 1 to 10, 15 to 18, and 23 to 24) were found to have superior coatability and adhesion to skin compared to pressure-sensitive adhesives obtained by curing pressure-sensitive adhesive compositions not of the present invention (Examples 11 to 14, and 21 to 22).

Claims

1. An adhesive composition comprising a hydroxyl-terminated urethane prepolymer, a solvent, and a healing agent, wherein the adhesive composition has a viscosity of 2500 to 85000 mPa·s at 25°C.

2. The pressure-sensitive adhesive composition according to claim 1, wherein the content of structural units based on ethylene oxide in the pressure-sensitive adhesive composition is 60 mass % or less.

3. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the hydroxyl-terminated urethane prepolymer has a content of structural units based on ethylene oxide of 60 mass % or less.

4. A method for producing an adhesive composition, comprising mixing a hydroxyl-terminated urethane prepolymer, a solvent, and a healing agent to produce an adhesive composition, 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, and the viscosity of the adhesive composition at 25°C is 2,500 to 85,000 mPa·s.

5. The method for producing a pressure-sensitive adhesive composition according to claim 4, wherein the amount of the tin-free catalyst is more than 0.001 parts by mass and less than 0.050 parts by mass per 100 parts by mass of the oxyalkylene polymer.

6. The method for producing a pressure-sensitive adhesive composition according to claim 4 or 5, wherein the tin-free catalyst is an organometallic catalyst.

7. The method for producing a pressure-sensitive adhesive composition according to claim 4 or 5, wherein the oxyalkylene polymer has an average number of hydroxyl groups per molecule of 1.5 to 3.

0.

8. A method for producing a pressure-sensitive adhesive composition according to claim 4 or 5, wherein the oxyalkylene polymer comprises an oxyalkylene polymer A having two or more hydroxyl groups per molecule, and an oxyalkylene polymer B having one hydroxyl group per molecule.

9. A pressure-sensitive adhesive which is a cured product of the pressure-sensitive adhesive composition according to claim 1.

10. A patch comprising a substrate and an adhesive layer provided on at least a portion of the surface of the substrate, the adhesive layer comprising the adhesive according to claim 9.

11. A transdermal absorption patch comprising at least one selected from the group consisting of the adhesive of claim 9 and the adhesive material of claim 10.

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