JP2012240937A - Adhesive composition for application to skin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition for application to skin, enabling a liquid to be absorbed rapidly at normal temperature, having an excellent liquid-retaining rate, and exhibiting excellent adhesiveness to the skin.SOLUTION: The adhesive composition for application to skin includes 30-200 pts.mass of a thermoplastic resin based on 100 pts.mass of a water-absorbing modified product of a polyalkylene oxide. The skin cataplasm is obtained by forming the composition into a sheet shape. For example, the water-absorbing modified product of the polyalkylene oxide is the one obtained by reacting a polyalkylene oxide compound and a diol compound with a diisocyanate compound. For example, the thermoplastic resin is at least one kind selected from the group consisting of an ethylene/vinyl acetate copolymer, an ethylene/acrylic acid copolymer and ethylene/ethyl acrylate copolymer.

Description

  The present invention relates to a pressure-sensitive adhesive composition for skin application having excellent skin adhesion when wet. More specifically, the present invention relates to a pressure-sensitive adhesive composition for skin patch comprising a modified water-absorbing polyalkylene oxide and a thermoplastic resin, and a skin patch obtained by processing the composition into a sheet and swelling it.

  2. Description of the Related Art In recent years, sheet-like skin patches that are directly applied to and adhered to skin such as the face and arms have been widely used for cosmetic pack sheets, external cooling sheets, and wound covering sheets.

  2. Description of the Related Art Conventionally, many cosmetic pack sheets have been known which are based on a cellulose fiber non-woven fabric for the purpose of moisturizing and cleaning. However, in these cases, although the nonwoven fabric itself has a high liquid-absorbing ability, there are problems such as poor liquid retention and easy liquid dripping and poor adhesion to the skin. In order to solve this problem, a carboxymethylated cellulose fiber nonwoven fabric has been proposed (Patent Document 1).

  In addition, compositions using hydrogel are known as an external cooling sheet for the purpose of lower heat and a skin patch type sheet for a cold insulation for poultice. As hydrogel, for example, a composition (Patent Document 2) composed of polyvinyl alcohol, water and cyclodextrin having high hydrophilicity and water absorption ability, acrylate water-soluble polymer, glycerin, propylene glycol, dry aluminum hydroxide gel In addition, a base material (Patent Document 3) in which tartaric acid and distilled water are mixed and allowed to stand for gelation is known. However, polyvinyl alcohol needs to be frozen after hydration and allowed to stand at room temperature for 10 hours, and in the case of an acrylate polymer, it is aged for 200 hours at 25 ° C. and 60% relative humidity. It takes a long time to change. In order to shorten the gelation time, water-soluble polymers such as polyacrylic acid, sodium polyacrylate, polyvinyl alcohol, etc., as a shape-retaining agent, inorganic powders such as smectite, kaolin, titanium oxide, and water, and high water absorption in polyhydric alcohols A composition containing a functional resin (Patent Document 4) and a hydrogel composed of a hydrophilic polymer, a hydrophobic polymer, and water crosslinked to prevent a decrease in adhesive strength due to sebum on the skin surface have also been proposed (Patent Document 5). ).

  In addition, when an acrylic resin is used as an adhesive, there is a problem that the adhesiveness at the time of skin application decreases due to sweat or the like, and in order to solve this, an acrylic ester and spherical silica are contained. A composition has also been proposed (Patent Document 6).

JP 2001-170104 A JP 62-53662 A International Publication WO2010 / 010756 Pamphlet JP 2002-136687 A JP 2010-285493 A JP 2008-167787 A

In the nonwoven fabric obtained by the method described in Patent Document 1, although the liquid retention rate was improved, the absolute amount of liquid retention was small and the adhesion with the skin was not sufficient.
Moreover, also in the hydrogel of patent document 4 and patent document 5 which has adhesiveness, time, such as mixing a water-soluble polymer and various components with a kneader or a mixer, was required. For this reason, there is a concern that the drug component may be decomposed by a change in temperature or shearing of a kneader or a mixer. In addition, it is necessary to mechanically mix various additive components with the composition containing the water-soluble polymer for a long time, which causes problems such as easy formation of bubbles during gelation and reduced adhesive strength.

  Even when the adhesive force described in Patent Document 6 is improved, it is difficult to uniformly disperse spherical silica and adjust the gel fraction, and further improvement in adhesiveness has been desired.

  An object of the present invention is to provide a pressure-sensitive adhesive composition for skin application, which can absorb liquid quickly at room temperature, has an excellent liquid retention rate, and has excellent adhesion to the skin.

  As a result of intensive studies to solve the above problems, the present inventors have found that a pressure-sensitive adhesive composition for skin application containing a water-absorbing polyalkylene oxide-modified product and a thermoplastic resin can absorb liquid in a short time at room temperature and is flexible. The present invention was completed by discovering that it is useful as an adhesive for skin application having excellent adhesion to the skin.

That is, the present invention
Item 1. A pressure-sensitive adhesive composition for skin application containing 30 to 200 parts by mass of a thermoplastic resin with respect to 100 parts by mass of a water-absorbing polyalkylene oxide-modified product;
Item 2. The water-absorbing polyalkylene oxide-modified product is a water-absorbing polyalkylene oxide-modified product obtained by reacting a polyalkylene oxide compound, a diol compound and a diisocyanate compound, having a water absorption capacity of 10 to 40 g / g and a water elution amount of Item 10. The adhesive composition for skin patch according to Item 1, which is a 10-30% water-absorbing polyalkylene oxide-modified product,
Item 3. Item 3. The adhesive for skin application according to item 1 or 2, wherein the thermoplastic resin is at least one selected from the group consisting of an ethylene / vinyl acetate copolymer, an ethylene / acrylic acid copolymer, and an ethylene / ethyl acrylate copolymer. Agent composition,
Item 4. Item 1. A skin patch using the skin adhesive composition according to any one of items 1 to 3,
About.

  Since the pressure-sensitive adhesive composition for skin application of the present invention has thermoplasticity, it can be subjected to general hot melt extrusion molding. There is no occurrence, excellent flexibility, and nonionic properties, so that salt such as sweat can be absorbed and adhesion to the skin does not deteriorate. Therefore, it can be widely used for cosmetic pack sheets, external cooling sheets, wound covering sheets, and the like. Moreover, since the adhesive composition for skin sticking has heat-sealing property, it can be used also as a cosmetic puff by covering them with a nonwoven fabric.

  The pressure-sensitive adhesive composition for skin application of the present invention comprises a water-absorbing polyalkylene oxide-modified product and a thermoplastic resin.

  The usage-amount of a thermoplastic resin is 30-200 mass parts with respect to 100 mass parts of water-absorbing polyalkylene oxide modified products, Preferably it is 40-150 mass parts. When the usage ratio of the thermoplastic resin is less than 30 parts by mass, the strength of the resulting adhesive composition for skin application may be reduced when the resulting adhesive composition is absorbed, resulting in poor adhesion to the skin. Moreover, when the usage-amount of a thermoplastic resin exceeds 200 mass parts, there exists a possibility that the liquid retention ability of the adhesive composition for skin sticking obtained may become low.

  As the water-absorbing polyalkylene oxide-modified product, a water-absorbing polyalkylene-modified product obtained by reacting a polyalkylene oxide compound, a diol compound and a diisocyanate compound is preferably used. Since the water-absorbing polyalkylene modified product has thermoplasticity, it has good compatibility with the thermoplastic resin, and can provide a pressure-sensitive adhesive composition for skin application excellent in water retention, flexibility, and adhesion.

  The water-absorbing ability of the water-absorbing polyalkylene oxide-modified product is preferably 10 to 40 g / g, more preferably 15 to 35 g / g. When the water absorbing ability of the water-absorbing polyalkylene oxide-modified product is less than 10 g / g, the water retaining ability of the obtained adhesive composition for skin patch may be lowered. When the water-absorbing ability of the water-absorbing polyalkylene oxide-modified product exceeds 40 g / g, the gel strength at the time of liquid absorption of the obtained adhesive composition for skin patch may be lowered. In the present invention, the water absorption capacity is a value measured by the method described later.

  The water elution content of the water-absorbing polyalkylene oxide-modified product is preferably 10 to 30%, more preferably 12 to 25%. When the water elution amount of the water-absorbing polyalkylene oxide-modified product is less than 10%, the adhesiveness of the obtained adhesive composition for skin application may be deteriorated. When the water elution amount of the water-absorbing polyalkylene oxide-modified product exceeds 30%, the skin may remain. In the present invention, the amount of water elution is a value measured by the method described later.

  When the melt viscosity of the water-absorbing polyalkylene oxide-modified product is measured using a flow tester (conditions: 170 ° C., 5.0 MPa, diameter 1 mm × length 1 mm using a die), 100 to 800 [Pa · s] It is preferable that it is 200-600 [Pa * s]. When the melt viscosity is less than 100 [Pa · s], the strength of the resulting adhesive composition for skin application at the time of liquid absorption may be lowered. If the melt viscosity exceeds 800 [Pa · s], the compatibility with the thermoplastic resin may be reduced.

  As said polyalkylene oxide compound, the polyalkylene oxide compound which has 90 mass% or more of ethylene oxide groups is preferable, and the polyalkylene oxide compound which has 95 mass% or more of ethylene oxide groups is more preferable. When the ethylene oxide group is less than 90% by mass, the water absorption rate of the obtained adhesive composition for skin application may be slow.

  The polyalkylene oxide compound is preferably a polyalkylene oxide compound having a number average molecular weight of 5,000 to 50,000, and more preferably a polyalkylene oxide compound having a number average molecular weight of 10,000 to 30,000. When the number average molecular weight is less than 5,000, there is a possibility that the liquid-absorbing ability of the obtained adhesive composition for skin application is lowered. When the number average molecular weight exceeds 50,000, the resulting water-absorbing polyalkylene oxide modified product has a high melt viscosity, poor compatibility with the thermoplastic resin, and may be difficult to thermoform.

  Examples of the diol compound include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,3-butanediol, 2,3-butanediol, and 1,4-butanediol. 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and the like. Among these diol compounds, ethylene glycol and 1,4-butanediol are preferably used from the viewpoint that the resulting water-absorbing polyalkylene oxide-modified product is excellent in water absorption ability and stability. These diol compounds may be used alone or in combination of two or more.

  The use ratio of the diol compound is preferably 0.8 to 2.5 mol, more preferably 1.0 to 2.0 mol, with respect to 1 mol of the polyalkylene oxide compound. When the use ratio of the diol compound is less than 0.8 mol, the strength of the obtained adhesive composition for skin patch when absorbed can be lowered. Moreover, when the usage-amount of a diol compound exceeds 2.5 mol, there exists a possibility that the liquid absorption ability of the adhesive composition for skin patches obtained may become low. The number of moles of the polyalkylene oxide compound can be determined by dividing its mass by the number average molecular weight.

  The diisocyanate compound is not particularly limited as long as it is a compound having two isocyanate groups (—NCO) in the same molecule. For example, 4,4′-diphenylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate ( HDI), dicyclohexylmethane-4,4′-diisocyanate (HMDI), 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate (IPDI), 1,8-dimethylbenzool-2,4 -Diisocyanate, 2,4-tolylene diisocyanate (TDI), etc. are mentioned. Among these diisocyanate compounds, dicyclohexylmethane-4,4′-diisocyanate (HMDI) and 1,6-hexamethylene diisocyanate (HDI) are preferable from the viewpoint of compatibility with thermoplastic resins and excellent stability. Preferably used. These diisocyanate compounds may be used alone or in combination of two or more.

  The ratio of each of the polyalkylene oxide compound, diol compound, and diisocyanate compound used is the ratio of the number of moles of isocyanate groups of the diisocyanate compound to the total number of moles of terminal hydroxyl groups of the polyalkylene oxide compound and hydroxyl groups of the diol compound [R value = (-NCO group / -OH group)] is preferably determined to be in the range of 0.7 to 1.2, more preferably 0.8 to 1.05. When the R value is less than 0.7, the resulting water-absorbing polyalkylene oxide-modified product may become water-soluble. Moreover, when R value exceeds 1.2, the melt viscosity of the water-absorbing polyalkylene oxide modified product to be obtained becomes high, and the compatibility with the thermoplastic resin may be deteriorated.

  Examples of a method of reacting a polyalkylene oxide compound, a diol compound, and a diisocyanate compound include a method of reacting by dissolving or dispersing in a reaction solvent such as toluene, xylene, dimethylformamide, or the like; After mixing, the method etc. which are made to react by heating to predetermined temperature are mentioned. From the viewpoint of industrial implementation, a method in which each raw material is continuously supplied in a molten state and mixed and reacted in a multi-screw extruder is preferable. The temperature of the reaction is preferably 70 to 210 ° C.

  Further, when producing a modified water-absorbing polyalkylene oxide, from the viewpoint of promoting the reaction, triethylamine, triethanolamine, dibutyltin dilaurate, dioctyltin dilaurate, tin 2-ethylhexanoate, triethylenediamine, etc. A small amount can be added.

  Thus, a water-absorbing polyalkylene oxide modified product can be obtained by reacting the polyalkylene oxide compound, the diol compound and the diisocyanate compound.

  Although it does not specifically limit as a thermoplastic resin, An ethylene / ethyl acrylate copolymer, an ethylene / methacrylic acid copolymer, an ethylene / vinyl acetate copolymer, an ethylene / acrylic acid copolymer, an ethylene / ethyl acrylate copolymer A coalescence or the like is preferably used. Among these thermoplastic resins, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer and ethylene / ethyl acrylate copolymer are used from the viewpoint of having good compatibility with the water-absorbing polyalkylene oxide-modified product. Preferably used. These thermoplastic resins may be used alone or in combination of two or more. In the present invention, a thermoplastic resin having a durometer D hardness (HDD) measured by a method described later of 10 to 60, preferably 20 to 50 is preferably used. When the HDD is less than 10, the obtained adhesive composition for skin application becomes too soft, and there is a possibility that it will be in a so-called non-sticky state. Moreover, when the said HDD exceeds 60, there exists a possibility that the adhesive composition for skin sticking obtained may become hard and adhesiveness may worsen.

  As a method for producing the adhesive composition for skin patch of the present invention, 1) a predetermined amount of the water-absorbing polyalkylene oxide-modified product and the thermoplastic resin are individually added or mixed with a Henschel mixer or a blender. A method in which the mixture is mixed using a machine and then supplied to a kneader, roll, extruder, etc. with a quantitative feeder, etc., and melt mixed. 2) In the previously melted thermoplastic resin, the polyalkylene oxide and the diol compound And a method of reacting a diisocyanate compound and the like.

  As an apparatus for performing the melting, melt mixing, and reaction, a twin screw extruder is preferably used from the viewpoint of excellent mixing of the components.

  The adhesive composition for skin application obtained in the present invention can be subjected to general melt extrusion molding, and can be molded into a sheet, rod, or film by an injection molding machine, an extrusion molding machine, an inflation molding machine or the like. Of these, inflation molding that allows easy thin film molding is preferably used. 50-300 micrometers is preferable and, as for the thickness of a film, 100-200 micrometers is more preferable. When the thickness is less than 50 μm, the strength is lowered and the adhesion to the skin may be deteriorated. If the thickness exceeds 300 μm, the dimensions during swelling may change significantly.

  When producing the adhesive composition for skin patch of the present invention, a stabilizer from the viewpoint of preventing the decomposition of each component and the obtained adhesive composition for skin patch, an ultraviolet absorber from the viewpoint of improving weather resistance, From the viewpoint of coloring, pigments, coloring agents, and the like may be added.

  The resulting melt-extruded product of the adhesive composition for skin application can absorb liquid at room temperature. The amount of liquid absorption can be controlled by the thermoplastic resin content, the thickness of the molded product, the liquid absorption time, and the like. Usually, it is preferable that the maximum liquid absorption is within 2 to 5 minutes.

  Moreover, since the adhesive composition for skin sticking of this invention does not have ionicity, unlike the conventional acrylic acid type water-soluble resin, salt absorption is also possible. Moreover, since the liquid can be absorbed at room temperature, an aqueous solution in which an easily decomposed drug such as ascorbic acid, sodium ascorbate, or ethyl ascorbic acid that is easily decomposed can be efficiently absorbed in a short time. A fat-soluble drug such as tocophenol can also be absorbed by solubilization in water using an emulsifier. Moreover, the adhesive composition for skin patches which absorbed these chemical | medical agents can release a chemical | medical agent effectively.

  Furthermore, the pressure-sensitive adhesive composition for skin application of the present invention has heat-sealability, and by combining the pressure-sensitive adhesive composition for skin application with a non-woven fabric made of rayon that does not have heat-sealability, At the same time, it can be made into a cosmetic sheet having a good touch.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[Evaluation method]
With respect to the water-absorbing polyalkylene oxide-modified product and the polyacrylate cross-linked product described in the production examples, (1) water absorption capacity, (2) water elution, and (3) melt viscosity were measured according to the following method. (4) Durometer D hardness (HDD) was measured according to the following method for the thermoplastic resin used in the examples and the adhesive composition for skin application obtained in the examples. For the adhesive compositions for skin application obtained in Examples and Comparative Examples, (5) swelling rate, (6) film strength, (7) diffusibility, penetration, and water retention were measured and evaluated according to the following methods. did. About the skin patches obtained using the adhesive compositions for skin patches of Examples and Comparative Examples, (8) adhesion, skin residue and liquid retention were measured and evaluated according to the following methods.

(1) Water absorption capacity The water absorption capacity of the modified polyalkylene oxide was measured by the following method.
About 1 g of the polyalkylene oxide-modified product was weighed (A [g]), and then immersed in 100 mL of ion-exchanged water measured in a 200 mL beaker at room temperature (22 ° C.) for 24 hours for gelation. It was. Thereafter, the gel was filtered with a wire mesh of 200 mesh (pore diameter: 75 μm), the mass (B [g]) was measured, and the water absorption capacity was calculated according to the following formula.
Water absorption capacity (g / g) = B / A

(2) Water elution amount The gel after measuring the water absorption capacity was weighed after drying for 8 hours with a hot air dryer at 50 ° C. (C [g]), and the water elution amount was determined by the following equation. .
Water elution (%) = (A−C) / A × 100

(3) Melt viscosity A 1.5 g sample was measured under the conditions shown below using a flow tester (manufactured by Shimadzu Corporation, model number: CFT-500C).
Load: 5.0 MPa
Measurement temperature: 170 ° C
Die diameter: 1mm
Die length: 1mm

(4) Durometer D hardness (HDD)
Japanese Industrial Standards: “Durometer Type D” means “hardness” measured in accordance with “Plastic Durometer Hardness Test Method” described in JIS K 7215 (1986). "After confirming that the flatness and parallelism of the sample surface and the adhesion between the sample surfaces were also good, the measurement was performed so that the thickness (T) of the sample was 6 mm or more.

(5) Swelling ratio The film of the adhesive composition for skin application obtained by Examples and Comparative Examples was cut into 2 cm (width: W) × 5 cm (length: L), and a measurement sample (mass A [g] ).
The measurement sample was swollen by being immersed in a metallic vat (20 cm × 30 cm × 3 cm) containing 100 ml of the absorbing solution at room temperature (22 ° C.) for 1 minute. Then, the measurement sample was taken out, the surface water was wiped using a paper towel, and the mass (B [g]) was measured.
Swell rate (%) = (B−A) / A × 100

(6) Film strength / flexibility The film obtained by the water absorption test was spread by hand, and the film was examined for tearing when it was wound around a polyethylene test tube (diameter 2.5 cm × length 12.5 cm).
○: There is no tearing, and there is flexibility, so that it can be wound tightly without any problem. Δ: There is flexibility, it can be wound, but it is torn.
X: If it is held by hand, it cannot be torn and wound.

(7) Diffusivity, penetration, water retention A film cut into a size of 6 cm × 6 cm as a sample on a filter paper (90 mm No. 1 manufactured by ADVANTEC) whose mass (C [g]) was measured in advance. Then, 2 ml of water colored with edible blue No. 1 was dropped on the sample over 10 seconds with a syringe and the following items were evaluated.

-The spread of water on the surface of the diffusible sample was observed.
○: Spreads throughout the sample.
X: Only the syringe part is wet and does not diffuse.

-The mass (D [g]) of the immersive filter paper was measured, and the penetration rate was calculated by the following formula.
Penetration rate [%] = (D−C) / 2 × 100

-Film mass before water retention colored water absorption (E [g]), film mass after colored water absorption (F0 [g]), and film after liquid absorption in a 40 ° C incubator for 15 minutes, 30 minutes The mass (F15, F30, F60 [g]) after storage for 60 minutes was measured, and the liquid retention of the gel film was determined by the following formula.
Water retention after 15 minutes (%) = (F0−F15) / (F0−E) × 100
Water retention after 30 minutes (%) = (F0−F15) / (F0−E) × 100
Water retention after 60 minutes (%) = (F0−F60) / (F0−E) × 100
If the water retention after 60 minutes is 40% or more, it can be judged as a good skin patch.

(8) Adhesion, skin residue, liquid retention A skin patch having the following composition was prepared.
1. Adhesive composition sheet for skin application-Adhesive composition for skin application 5 parts by mass-Glycerin 4 parts by mass-Propylene glycol 4 parts by mass-Distilled water 87 parts by mass Film of adhesive composition for skin application cut to 6 cm diameter Was immersed in a solution in which glycerin, propylene glycol and distilled water of the above-mentioned parts by mass were mixed for 5 minutes to absorb the entire amount to obtain a skin patch.

2. Acrylate-based water-soluble polymer sheet-Acrylate-based water-soluble polymer 5 parts by mass-Glycerin 4 parts by mass-Propylene glycol 4 parts by mass-Dry aluminum hydroxide gel 0.2 parts by mass-Tartaric acid 0.25 parts by mass-Distillation Water 86.55 parts by mass A mixed solvent consisting of 4 parts by mass of glycerin and 4 parts by mass of propylene glycol, 5 parts by mass of an acrylate-based water-soluble polymer, dry aluminum hydroxide gel (manufactured by Kyowa Chemical Industry Co., Ltd., model number: S- 100, acid reactivity: 0.1N-HCI = 180 seconds) 0.2 parts by mass was added and dispersed, and this was designated as solution A. Next, 0.25 part by mass of tartaric acid was added to 86.55 parts by mass of distilled water and dissolved, and this was designated as B solution. A whole amount of liquid A was added to a 500 ml beaker, and the whole amount of liquid B was added while stirring at 500 rpm using a pitched paddle having a blade diameter of 75 mm, and the gel was prepared by stirring for 30 seconds.

[Aging of gel]
115-120 g of the prepared gel was transferred to a polyethylene container (manufactured by As One Co., Ltd., trade name: Tightboy TB-2), and a conditioning mixer (manufactured by Shinky Co., Ltd., trade name: Awatori Rentaro MX-201 type) was used. After degassing for 1.5 minutes, the gel was obtained by putting it in a thermo-hygrostat (trade name: LHU-113 type, manufactured by ESPEC CORP.) Adjusted to 250 ° C. and a relative humidity of 60% and aged for 200 hours. Was cut into a skin patch sheet having a diameter of 6 cm and a thickness of 1 cm.

-Adhesion , skin stiffness test Artificial leather (suprale made by Idemitsu Technofine) is attached to a 10cm x 10cm x 0.30cm thick iron plate with double-sided tape, and the above-mentioned skin patch is placed on it, 141g of 6cm diameter The load was applied for 30 seconds (pressure of 5 g / cm 2). Then, the iron plate was set up vertically and stored in a thermostat at 40 ° C. for 4 hours to check the adhesion.
○: not peeled △: partly peeled ×: peeled off

After confirming the adhesion, the skin patch was peeled off, and the polymer remaining on the surface of the artificial leather was observed with the naked eye.
◯: No polymer remaining, no trace left peeled Δ: No polymer left, but trace left peeled ×: Polymer left.

Liquid retention test Film or sheet mass before liquid absorption (G [g]), film or sheet mass after liquid absorption (H0 [g]), and film after liquid absorption in a 40 ° C. incubator for 15 minutes The mass (H15, H30, H60 [g]) after storage for 30 minutes and 60 minutes was measured, and the liquid retention rate of the gel sheet was determined by the following formula. In addition, when the liquid retention after 60 minutes is 50% or more, it can be determined as a good skin patch.
Liquid retention after 15 minutes (%) = (H0−H15) / (H0−G) × 100
Liquid retention after 30 minutes (%) = (H0−H30) / (H0−G) × 100
Retention rate after 60 minutes (%) = (H0−H60) / (H0−G) × 100

[Production Example 1] Production of modified water-absorbing polyalkylene oxide 100 parts by mass of polyethylene oxide having a number average molecular weight of 20,000 sufficiently dehydrated in a storage tank A equipped with a stirrer kept at 80 ° C, 1,4- The mixture was added at a ratio of 0.90 parts by mass of butanediol and 0.1 parts by mass of dioctyltin dilaurate and stirred in a nitrogen gas atmosphere to obtain a uniform mixture. Separately, dicyclohexylmethane-4,4′-diisocyanate was charged into storage tank B kept at 30 ° C. and stored in a nitrogen gas atmosphere.
Using a metering pump, set the mixture in storage tank A at a rate of 500 g / min and dicyclohexylmethane-4,4′-diisocyanate in storage tank B at a rate of 19.4 g / min. Was continuously fed to the twin-screw extruder (R value = 1.00), mixed and reacted in the extruder, a strand was taken out from the outlet of the extruder, pelletized by a pelletizer, and water-absorbing polyalkylene oxide A modified product was obtained.
The water-absorbing polyalkylene oxide modified product obtained had a water absorption capacity of 25 g / g, a water elution content of 19%, and a melt viscosity of 320 Pa · s.

[Production Example 2] Production of water-absorbing polyalkylene oxide modified product An ethylene oxide / propylene oxide (mass ratio: 90/10) copolymer having a number average molecular weight of 15,000 was heated to 40 ° C at a rate of 250 g / min. Ethylene glycol was supplied at a rate of 2.1 g / min to a 40 mmφ single screw extruder (L / D = 40, set temperature: 90 ° C.), and both were melt mixed.
A mixture obtained from the discharge port (discharged in a uniform molten state and analyzed by LC and confirmed to be mixed at a charging ratio) was mixed with a 30 mmφ twin-screw extruder (L / D = 41. 5) was continuously supplied to the hopper port (set temperature: 80 ° C.). At the same time, dioctyltin dilaurate was supplied to the hopper port of the twin-screw extruder at a rate of 0.5 g / min.
Separately, dicyclohexylmethane-4,4′-diisocyanate adjusted to 30 ° C. is supplied at a rate of 12.4 g / min to the screw barrel portion located downstream of the hopper port of the twin-screw extruder. (R value = 0.95), the reaction was continued under a nitrogen atmosphere (set temperature: 180 ° C.). The strand obtained from the twin-screw extruder outlet was cooled and then pelletized with a pelletizer to obtain a modified water-absorbing polyalkylene oxide.
The water-absorbing polyalkylene oxide modified product obtained had a water absorption capacity of 20 g / g, a water elution content of 15%, and a melt viscosity of 150 Pa · s.

[Production Example 3] Production of acrylate-based water-soluble polymer A 1000 ml five-round cylindrical round bottom flask equipped with a reflux condenser, a dropping funnel, a nitrogen gas introduction tube, a stirrer and a stirring blade was prepared. Into this flask, 340 g of n-heptane was added, 0.92 g of sucrose stearate ester of HLB3 (manufactured by Mitsubishi Chemical Foods Co., Ltd., Ryoto Sugar Ester S-370) and maleic anhydride modified ethylene / propylene copolymer (Mitsui 0.92 g of High Wax 1105A, manufactured by Chemical Co., Ltd. was added, the temperature was raised to 80 ° C. with stirring to dissolve the surfactant, and then cooled to 55 ° C.
On the other hand, 92 g (1.02 mol) of 80% by mass acrylic acid aqueous solution was put into a 500 ml Erlenmeyer flask, and 54.5 g (0.41 mol) of 30% by mass sodium hydroxide aqueous solution was added while cooling from the outside. After dropwise addition and neutralization of 40 mol%, 1.15 g of a 2.0 mass% aqueous solution of 2,2'-azobis (2-amidinopropane) dihydrochloride as a radical polymerization initiator, sodium hypophosphite A monomer aqueous solution was prepared by adding 0.92 g of a 1.0% by weight aqueous solution of monohydrate and 60 g of ion-exchanged water and dissolving.
The entire amount of the monomer aqueous solution was added to the cylindrical round bottom flask. The flask was immersed in a 60 ° C. water bath and heated to 58 ° C., and the system was purged with nitrogen to carry out a polymerization reaction. After 30 minutes, the peak temperature reached 79 ° C., and the state of being immersed in a 60 ° C. water bath for 0.5 hours was maintained and the reaction was continued. The internal solution temperature after 0.5 hours was 59 ° C. The obtained polymerization slurry was cooled to 30 ° C. and sampled, and the polymerization rate was measured. The polymerization rate was 96 mol%.
After completion of the polymerization, the temperature of the polymerization slurry was raised in an oil bath at 125 ° C., and 106 g of water was removed from the system by refluxing n-heptane by azeotropic distillation of n-heptane and water. Furthermore, n-heptane in the system was removed by distillation and dried to obtain 86.1 g of an acrylate-based water-soluble polymer. The resulting polyacrylate-based polymer was water-soluble and did not absorb water and was infusible to heat, so the melt viscosity could not be measured.

[Example 1]
Modified water-absorbing polyalkylene oxide and ethylene / vinyl acetate copolymer obtained in the same manner as in Production Example 1 [abbreviation: EVA, manufactured by Sumitomo Chemical Co., Ltd .: Evertate D3010, vinyl acetate content = 10%, melt index (MI ) = 6, HDD 35] at a supply rate of 8 kg / hr and 3.5 kg / hr, respectively, are supplied to a 28 mmφ twin screw extruder (L / D = 40) set at 130 ° C. A pressure-sensitive adhesive composition was obtained. Table 1 shows the composition ratio of the adhesive composition for skin application.
The obtained pressure-sensitive adhesive composition for skin application was 10 cm (W) × 10 cm (L) × 0.00 using a hot press (40 g press, pressure: 50 kg / cm ² ) manufactured at 150 ° C. Durometer D hardness (HDD) was determined by molding into a 10 cm (T) sheet.
Moreover, an extruder (SYH25-25, L / D = 25 manufactured by Shinko Machinery Co., Ltd.) and an inflation molding machine (SF- manufactured by Shinko Machinery Co., Ltd.) in which the obtained adhesive composition for skin application was set to 130 to 150 ° C. 300) to obtain an inflation film having a width of 160 mm and a thickness of 120 μm.
The obtained inflation film of the adhesive composition for skin application was cut into a predetermined size for evaluation. The results are shown in Table 2.

[Example 2]
Modified water-absorbing polyalkylene oxide and ethylene / acrylic acid copolymer obtained in the same manner as in Production Example 1 [abbreviation: EAA, manufactured by Dow Chemical Company: Primacol 5980, acrylic acid content = 20%, MI = 300, HDD40] is supplied to a 28 mmφ twin screw extruder (L / D = 40) set at 140 ° C. at a supply rate of 8 kg / hr and 14 kg / hr, respectively, and melt-mixed to obtain an adhesive composition for skin application. Obtained. Table 1 shows the composition ratio of the adhesive composition for skin application.
The obtained adhesive composition for skin application was 10 cm (W) × 10 cm (L) × using a hot press (manufactured by Gonno Hydraulic Machinery Co., Ltd., 40 t press, pressure: 50 kg / cm ² ) set to 130 ° C. Molded into a 0.1 cm (T) sheet.
Moreover, an extruder (SYH25-25, L / D = 25 manufactured by Shinko Machinery Co., Ltd.) and an inflation molding machine (SF- manufactured by Shinko Machinery Co., Ltd.) in which the obtained adhesive composition for skin application was set to 130 to 150 ° C. 300) to obtain an inflation film having a width of 160 mm and a thickness of 150 μm.
The obtained inflation film of the adhesive composition for skin application was cut into a predetermined size for evaluation. The results are shown in Table 2.

[Example 3]
Modified water-absorbing polyalkylene oxide obtained in the same manner as in Production Example 2, ethylene / acrylic acid copolymer [abbreviation: EAA, manufactured by Dow Chemical Co .: Primacol 3460, acrylic acid content = 9.7%, MI = 20, HDD42] and ethylene / vinyl acetate copolymer [abbreviation: EVA, manufactured by Sumitomo Chemical Co., Ltd .: Evaate D3010, vinyl acetate content = 10%, melt index (MI) = 6, HDD35], 5 kg / hr, 3 Supplied to a 28 mmφ twin screw extruder (L / D = 40) set at 130 ° C. with a supply amount of .75 kg / hr and 3.75 kg / hr, and melt mixed to obtain an adhesive composition for skin application. It was. Table 1 shows the composition ratio of the adhesive composition for skin application.
The obtained adhesive composition for skin application was 10 cm (W) × 10 cm (L) × using a hot press (manufactured by Gonno Hydraulic Machinery Co., Ltd., 40 t press, pressure: 50 kg / cm ² ) set to 130 ° C. Molded into a 0.1 cm (T) sheet.
Moreover, an extruder (SYH25-25, L / D = 25 manufactured by Shinko Machinery Co., Ltd.) and an inflation molding machine (SF- manufactured by Shinko Machinery Co., Ltd.) in which the obtained adhesive composition for skin application was set to 130 to 150 ° C. 300) to obtain an inflation film having a width of 160 mm and a thickness of 180 μm.
The obtained inflation film sheet of the adhesive composition for skin application was cut into a predetermined size for evaluation. The results are shown in Table 2.

[Comparative Example 1]
Modified water-absorbing polyalkylene oxide and ethylene / vinyl acetate copolymer obtained in the same manner as in Production Example 1 [abbreviation: EVA, manufactured by Sumitomo Chemical Co., Ltd .: Evertate D3010, vinyl acetate content = 10%, MI = 6, HDD35] is supplied to a 28 mmφ twin screw extruder (L / D = 40) set at 130 ° C. at a supply rate of 10 kg / hr and 2.5 kg / hr, respectively, and melt-mixed to produce an adhesive composition for skin application. I got a thing. Table 1 shows the composition ratio of the adhesive composition for skin application.
The obtained pressure-sensitive adhesive composition for skin application was 10 cm (W) × 10 cm (L) × 0.00 using a hot press (40 g press, pressure: 50 kg / cm ² ) manufactured at 150 ° C. Durometer D hardness (HDD) was determined by molding into a 10 cm (T) sheet.
Moreover, an extruder (SYH25-25, L / D = 25 manufactured by Shinko Machinery Co., Ltd.) and an inflation molding machine (SF- manufactured by Shinko Machinery Co., Ltd.) in which the obtained adhesive composition for skin application was set to 130 to 150 ° C. 300) to obtain an inflation film having a width of 160 mm and a thickness of 120 μm.
The obtained inflation film of the adhesive composition for skin application was cut into a predetermined size for evaluation. The results are shown in Table 2.

[Comparative Example 2]
Modified water-absorbing polyalkylene oxide and ethylene / acrylic acid copolymer obtained in the same manner as in Production Example 1 [abbreviation: EAA, manufactured by Dow Chemical Company: Primacol 5980, acrylic acid content = 20%, MI = 300, HDD40] is supplied to a 28 mmφ twin screw extruder (L / D = 40) set at 130 ° C. at a supply rate of 10 kg / hr and 4 kg / hr, respectively, and melt-mixed to obtain an adhesive composition for skin application. Obtained. Table 1 shows the composition ratio of the adhesive composition for skin application.
The obtained pressure-sensitive adhesive composition for skin application was 10 cm (W) × 10 cm (L) × 0.00 using a hot press (40 g press, pressure: 50 kg / cm ² ) manufactured at 150 ° C. Durometer D hardness (HDD) was determined by molding into a 10 cm (T) sheet.
Moreover, an extruder (SYH25-25, L / D = 25 manufactured by Shinko Machinery Co., Ltd.) and an inflation molding machine (SF- manufactured by Shinko Machinery Co., Ltd.) in which the obtained adhesive composition for skin application was set to 130 to 150 ° C. 300) to obtain an inflation film having a width of 160 mm and a thickness of 150 μm.
The obtained inflation film of the adhesive composition for skin application was cut into a predetermined size for evaluation. The results are shown in Table 2.

[Comparative Example 3]
Modified water-absorbing polyalkylene oxide obtained in the same manner as in Production Example 2, ethylene / vinyl acetate copolymer [abbreviation: EVA, manufactured by Mitsui DuPont Polychemicals: Everflex EV45LX, vinyl acetate content = 46%, MI = 2.5, HDD8] and ethylene / acrylic acid copolymer [abbreviation: EAA, manufactured by Dow Chemical Company: Primacol 3460, acrylic acid content = 9.7%, MI = 20, HDD42], respectively, 12 kg / hr, 0 Supplied to a 28 mmφ twin screw extruder (L / D = 40) set at 130 ° C. at a supply rate of 0.5 kg / hr and 0.5 kg / hr, melt mixed to obtain an adhesive composition for skin application It was. Table 1 shows the composition ratio of the adhesive composition for skin application.
The obtained pressure-sensitive adhesive composition for skin application was 10 cm (W) × 10 cm (L) × 0.00 using a hot press (40 g press, pressure: 50 kg / cm ² ) manufactured at 150 ° C. Durometer D hardness (HDD) was determined by molding into a 10 cm (T) sheet.
Moreover, an extruder (SYH25-25, L / D = 25 manufactured by Shinko Machinery Co., Ltd.) and an inflation molding machine (SF- manufactured by Shinko Machinery Co., Ltd.) in which the obtained adhesive composition for skin application was set to 130 to 150 ° C. 300) to obtain an inflation film having a width of 160 mm and a thickness of 150 μm.
The obtained inflation film of the adhesive composition for skin application was cut into a predetermined size for evaluation. The results are shown in Table 2.

[Comparative Example 4]
Acrylate-based water-soluble polymer and ethylene / vinyl acetate copolymer obtained in the same manner as in Production Example 3 [abbreviation: EVA, manufactured by Sumitomo Chemical Co., Ltd .: Evertate D3010, vinyl acetate content = 10%, melt index (MI ) = 6, HDD35] were supplied to a 28 mmφ twin screw extruder (L / D = 40) set at 130 ° C. with supply rates of 8 kg / hr and 3.5 kg / hr, respectively. A composition was not obtained.
Therefore, the evaluation results of the acrylate-based water-soluble polymer sheet prepared in the evaluation method (8) are shown in Table 2 instead.

  As is clear from the results shown in Table 2, the skin obtained using the adhesive composition for skin application containing 30 to 200 parts by mass of a thermoplastic resin with respect to 100 parts by mass of the water-absorbing polyalkylene oxide-modified product The patch absorbs liquid in a short time and gels, compared to conventional acrylate polymers, and has excellent adhesion and less skin residue.

  The skin patch using the pressure-sensitive adhesive composition for skin patch according to the present invention absorbs liquid in a short time and is excellent in water retention, flexibility and adhesion, and is used for cosmetic packs, wound dressings, and cooling sheets. Can be widely used.

Claims (4)

  A pressure-sensitive adhesive composition for skin application containing 30 to 200 parts by mass of a thermoplastic resin with respect to 100 parts by mass of a water-absorbing polyalkylene oxide-modified product.   The water-absorbing polyalkylene oxide-modified product is a water-absorbing polyalkylene oxide-modified product obtained by reacting a polyalkylene oxide compound, a diol compound and a diisocyanate compound, having a water absorption capacity of 10 to 40 g / g and a water elution amount of The pressure-sensitive adhesive composition for skin application according to claim 1, which is a 10-30% water-absorbing polyalkylene oxide-modified product.   3. The skin patch according to claim 1, wherein the thermoplastic resin is at least one selected from the group consisting of an ethylene / vinyl acetate copolymer, an ethylene / acrylic acid copolymer, and an ethylene / ethyl acrylate copolymer. Adhesive composition.   A skin patch using the skin adhesive composition according to any one of claims 1 to 3.