JP2009101194A - Base sheet for skin patch, and skin patch using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base sheet for a skin patch, in which there is no such transfer of medicine or additive in a layer of adhesive agent as to swell the base sheet, having such flexibility as to follow the skin favorably to achieve excellent user-friendliness; and to provide a skin patch using the same. <P>SOLUTION: The base sheet for skin patch comprises a polyolefinic resin film, 50-200 μm thick, comprising a resin composite of (a) at least one selected from among low density polyethylene resin and olefin-based thermoplastic elastomer, by 90-100 wt.% in total, (b) random polypropylene resin by 0.5 wt.%, and (c) ethylene-butylene random copolymer by 0-5 wt.%, wherein the polyolefinic resin film is bonded to a polyethylene terephthalate film, 1.8-5 μm thick, by adhesive agent. Its 10% modulus falls within a range of 5-35 N/19 mm width both vertically and laterally. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a base sheet for a skin patch and a skin patch using the same. Specifically, the present invention has no transition to the base sheet of additives such as liquid paraffin and tackifier, which are usually contained in the adhesive layer, in addition to the drug in the adhesive layer. The present invention relates to a base sheet for a skin patch that closely follows the expansion and contraction of a worn skin, and an easy-to-use skin patch using such a base sheet. Furthermore, this invention relates to the manufacturing method of the said base material sheet for skin patches.

  Conventionally, for example, an adhesive skin patch obtained by laminating an adhesive containing a drug such as an anti-inflammatory analgesic or a TTS preparation on a base sheet has been widely used for medical applications as a transdermal drug. As a base material sheet for such a skin patch, a vinyl chloride resin that has been conventionally flexible and compatible with the skin has been widely used. On the other hand, when using a base material sheet made of a vinyl chloride resin, If the chemicals in the pressure-sensitive adhesive layer and additives such as liquid paraffin and tackifier that are usually contained in the pressure-sensitive adhesive layer migrate from the pressure-sensitive adhesive layer into the base sheet, and the base sheet is swollen and altered Therefore, it is difficult to control the administration of the drug over time, and there is a problem that the desired therapeutic effect is impaired. In addition, there is also a problem that the plasticizer contained in the vinyl chloride resin sheet migrates into the pressure-sensitive adhesive layer containing the drug and impairs the performance of the pressure-sensitive adhesive.

  Therefore, in order to solve such problems, for example, a soft vinyl chloride resin film blended with a high molecular weight polyester plasticizer is laminated and adhered to the surface of a polyethylene terephthalate film having excellent chemical resistance and solvent resistance. A skin patch in which a pressure-sensitive adhesive layer containing a drug is provided and a polyethylene terephthalate film functions as a barrier layer has been proposed (see, for example, Patent Document 1). In such a skin patch, the drug or additive in the adhesive layer does not migrate to the base sheet, and the plasticizer in the base sheet also does not migrate into the adhesive layer. Moreover, since it is flexible and follows the skin well, it is easy to use.

  However, in recent years, since vinyl chloride resin may generate harmful dioxins at the time of incineration, from the viewpoint of environmental protection, an alternative to non-chlorinated materials is also required for base sheets for skin patches. .

  As described above, the polyethylene terephthalate film is excellent in chemical resistance and solvent resistance among non-chlorinated materials, but is extremely hard if the polyethylene terephthalate film alone has an appropriate thickness as a base sheet. Because there is no flexibility and followability to the skin, the skin patch sheet using such a polyethylene terephthalate film as a base sheet is not easy to use, and the edge of the sheet is lifted when it is attached to the skin. Insufficient therapeutic effect and may damage the skin.

JP-A-1-249719

  The present invention was made in order to solve the above-described various problems in conventional skin patches and a base sheet therefor, and the chemicals and additives in the adhesive layer are transferred to the base sheet. An object of the present invention is to provide an easy-to-use skin patch and a base material sheet therefor, which does not swell the base material sheet, and which is flexible and follows the skin well. Furthermore, an object of this invention is to provide the manufacturing method of such a base sheet for skin patches.

  According to the present invention, at least one selected from a low density polyethylene resin and an olefinic thermoplastic elastomer is 50 to 100% by weight, a random polypropylene resin is 0 to 30% by weight, and an ethylene-butylene random copolymer is 0 to 20% by weight. A 50-200 μm-thick polyolefin resin film comprising a resin composition is bonded to a polyethylene terephthalate film having a thickness of 10 μm or less with an adhesive, and a skin patch having a 10% modulus of 35 N / 19 mm width or less in both length and width A medicinal substrate sheet is provided.

  Furthermore, according to this invention, the skin patch which consists of the said base material sheet and the adhesive layer containing the chemical | medical agent provided in the back surface of the polyethylene terephthalate film of this base material sheet is provided.

  According to the base sheet for skin patches of the present invention, a flexible and elastic polyolefin resin film is bonded to a flexible and strong polyethylene terephthalate film, while having strength and flexibility as a base sheet. It has moderate elasticity and elasticity to follow the elongation of the skin well.

  Therefore, according to the skin patch obtained by laminating the pressure-sensitive adhesive layer containing various additives on the polyethylene terephthalate film of such a base sheet, it is easy to use and easy to apply to the skin. Moreover, the polyethylene terephthalate film functions as a barrier layer, and even if the drug is highly osmotic and diffusible, such as L-menthol or glycol salicylate, the adhesive layer is a polyolefin such as liquid paraffin. Even when containing additives that are highly compatible with resin films, these drugs and additives do not migrate into the polyethylene terephthalate film and do not permeate and diffuse. Can do.

  In addition, according to the present invention, if a polyethylene terephthalate film is adhered to a polyolefin resin film by dry lamination using a one-pack or two-pack polyurethane adhesive, the substrate sheet according to the present invention can be produced with good productivity. Obtainable.

  In the base sheet for skin patches according to the present invention, the polyethylene terephthalate film needs to have a thickness of 10 μm or less. When the thickness of the polyethylene terephthalate film exceeds 10 μm, the obtained base sheet is too hard to be used as a base sheet for skin patches, and the followability to the skin is poor. According to the present invention, the thickness of the polyethylene terephthalate film is usually preferably 7.5 μm or less, particularly in the range of 1.8 to 5 μm so that the obtained base sheet has flexibility. Is preferred.

Therefore, according to the present invention, for example, a polyethylene terephthalate film having a thickness of 3.5 μm, a breaking strength of 29.4 kgf / mm ² , and a 2% (longitudinal direction) modulus of 8.6 kgf / mm ² can be suitably used. .

  The base material sheet for skin patches according to the present invention is obtained by bonding a polyolefin resin film to such a polyethylene terephthalate film with an adhesive, and the base material sheet thus obtained is flexible and follows the skin. The polyolefin resin film has at least one selected from a low-density polyethylene resin and an olefin-based thermoplastic elastomer as its base resin so that it has excellent strength and has the required strength. Further, as a required characteristic from the application, the thickness needs to be in the range of 50 to 200 μm.

  In the present invention, the low-density polyethylene resin is not particularly limited, but a so-called metallocene-catalyzed linear low-density polyethylene resin (LLDPE) is preferably used. Further, as the TPO, as one of them, a so-called reactor TPO made of a block or graft copolymer having polypropylene and (in some cases polybutene) and an ethylene-propylene copolymer component is well known. According to the present invention, such a reactor TPO is preferably used. As specific examples of such a reactor TPO, for example, “Cataloy” of Montel Co., “PER” of Tokuyama Co., Ltd., “Newcon” of Chisso Co., Ltd., etc. are known as commercially available products. In such a case, such a commercially available product can be suitably used. Such low density polyethylene resin and olefinic thermoplastic elastomer are used alone or as a mixture.

  According to the present invention, if necessary, a polyolefin resin film can be formed using a random polypropylene resin or an ethylene-butylene random copolymer together with the base resin. The random polypropylene resin is useful for imparting moderate hardness to the resulting polyolefin resin film, and is used in the range of 0 to 30% by weight, preferably 3 to 25% by weight of the resin composition. As such a random polypropylene resin, for example, J Allomer PM620 manufactured by Nippon Polyolefin Co., Ltd. is known as a commercial product. In this invention, such a commercial item can be used conveniently.

  On the other hand, the ethylene-butylene random copolymer is useful for imparting flexibility to the resulting polyolefin resin film, and is in the range of 0 to 20% by weight, preferably in the range of 3 to 15% by weight of the resin composition. Used in As an ethylene-butylene random copolymer, for example, EMB2041P manufactured by JSR Corporation is known as a commercially available product. In this invention, such a commercial item can be used conveniently.

  Furthermore, according to the present invention, the base sheet in which the polyolefin resin film is bonded to the polyethylene terephthalate film with an adhesive as described above is a flexible, easy-to-use skin patch having a waist. 10% modulus (specimen 19 mm width strip, chuck width 100 mm, marked line 50 mm, tensile speed 50 mm / min) is required to be 35 N / 19 mm width or less in both length and width, It is preferably in the range of 5 to 35 N / 19 mm width.

  According to the present invention, the polyethylene terephthalate film and the polyolefin resin film are bonded with an adhesive. As this adhesive, in particular, a one-component or two-component polyurethane adhesive is preferably used, and among these one-component or two-component polyurethane adhesives, a polyester polyurethane adhesive is preferably used.

  The means for adhering the polyethylene terephthalate film and the polyolefin resin film using such a one-pack type or two-pack type polyurethane adhesive is not particularly limited. It is advantageous in terms of production efficiency to apply a two-component polyurethane adhesive, dry it, and if necessary, apply heat and dry lamination with a polyethylene terephthalate film. In the material sheet, strong adhesion can be obtained between the polyethylene terephthalate film and the polyolefin resin film.

  The skin patch according to the present invention is obtained by laminating an adhesive layer containing a drug on the polyethylene terephthalate film of such a base sheet. Here, the pressure-sensitive adhesive is not particularly limited, but has not only excellent adhesiveness when the skin patch is applied to the skin, conformability to the skin, moderate elasticity, etc., but also when the skin is peeled off. A styrene-diene-styrene block copolymer, an acrylic acid alkyl ester copolymer, and the like are preferably used because they can be easily peeled off without causing irritation.

  Specific examples of such styrene-diene-styrene block copolymers include styrene-butadiene-styrene block copolymers and styrene-isoprene-styrene block copolymers. These styrene-diene-styrene block copolymers may be used alone or as a mixture as an adhesive. In addition to the liquid paraffin and tackifier, as described above, the pressure-sensitive adhesive can be selected from various types such as polyisobutylene, rosin-modified resin, hydrogenated rosin ester, plasticizer, filler, and anti-aging agent. An additive may be contained.

  The skin patch according to the present invention is obtained by mixing various drugs with the above-mentioned pressure-sensitive adhesive and laminating them on a polyethylene terephthalate film of a base sheet. Therefore, the drug is not particularly limited as long as it is a transdermal drug, and includes, for example, local stimulants, anti-inflammatory agents and analgesics, central nervous agents (sleep sedatives, antiepileptics) , Neuropsychiatric agents), diuretics, antihypertensive agents, coronary vasodilators, antitussive expectorants, antihistamines, arrhythmic agents, cardiotonic agents, sex hormone agents, corticosteroids, local anesthetics, antifungal agents, etc. be able to. These drugs are used alone or in combination of two or more. More specifically, examples of the local stimulant, anti-inflammatory agent and analgesic include salicylic acid, methyl salicylate, glycol salicylate, L-menthol, mint oil, thymol and the like.

  The ratio of such a drug in the pressure-sensitive adhesive layer depends on the drug and is not limited at all, but is usually in the range of 1 to 25% by weight, preferably 5 to 20% by weight.

  Hereinafter, the present invention will be described by way of examples together with comparative examples, but the present invention is not limited to these examples. As described above, the ratio of the drug in the pressure-sensitive adhesive layer is usually very small, and since the effect of the drug used for the skin patch is already well known, styrene-diene-styrene is used here. Only the tackifier (terpene resin) and liquid paraffin are blended into the pressure-sensitive adhesive made of the block copolymer, and this is coated on the base sheet, forming a pressure-sensitive adhesive layer to form a pressure-sensitive adhesive sheet. The characteristics were substantially the characteristics of the skin patch. The characteristics of the base sheet and the pressure-sensitive adhesive sheet were evaluated as follows. The results are shown in Tables 1 and 2.

(10% modulus of base sheet)
Using a strip-shaped sample having a width of 19 mm, measurement was performed at a chuck width of 100 mm, a marked line interval of 50 mm, and a tensile speed of 50 mm / min.

(Swellability of base sheet)
With the release paper stuck on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, it was cut into 10 cm squares, placed in a bag made of an aluminum / polyethylene film laminate, and sealed by heat sealing. After leaving this in an oven at 40 ° C. for one month, the adhesive sheet is taken out, and the dimensional change in the vertical and horizontal directions of the polyethylene terephthalate film is examined. Both the vertical and horizontal dimensional changes in the film are 0.1%. When it was less than ◯, it was evaluated as ◯, and when the dimensional change in the vertical or horizontal direction of the film was 0.1% or more, it was evaluated as x.

(Bleedability to substrate sheet)
After evaluating the swelling property of the base material sheet in the pressure-sensitive adhesive sheet as described above, the presence or absence of bleed of the tackifier or liquid paraffin on the surface of the polyethylene terephthalate film is visually checked, and there is no bleed. Time was marked with x.

(Flexibility and texture evaluation of adhesive sheet (sensory test))
An adhesive sheet was stuck on the back of the hand, and the adhesion to skin, followability, conformability, and bendability were comprehensively evaluated visually and by hand. When the skin was well tracked and the adhesion, conformability, and bendability were good, there was a slightly hard sensation, but practically no problem was indicated by Δ, and when it was hard and practical, it was indicated by ×.

Example 1
(Manufacture of base sheet)
As a polyolefin resin, 50 parts by weight of a linear low density polyethylene resin (Carnel KF281 manufactured by Nippon Polychem Co., Ltd.), 40 parts by weight of a reactor TPO (PER210E manufactured by Tokuyama Co., Ltd.), a random polypropylene resin (manufactured by Nippon Polyolefin Co., Ltd.) 100 parts by weight of a mixture consisting of 5 parts by weight of J Allomer PM620) and 5 parts by weight of an ethylene-butylene copolymer (EBM2041P manufactured by JSR Corporation) was used as an antioxidant (Antifox 10 manufactured by Nippon Oil & Fats Co., Ltd.). An embossed film having a thickness of 100 μm was produced by melt kneading together with 1 part by weight using a Banbury mixer and calendering.

  A two-component polyurethane adhesive (Seiko Kasei Co., Ltd.) was applied to the adhesive surface (non-embossed surface) of this embossed film, dried, and then a 4.5 μm polyethylene terephthalate film (Teijin DuPont Co., Ltd.). The base sheet was obtained.

(Manufacture of adhesive sheet)
30 parts by weight of a styrene-isoprene-styrene block copolymer (Califlex TR-1107 manufactured by Shell Chemical Co., Ltd.), 35 parts by weight of a terpene resin (YS resin manufactured by Yasuhara Chemical Co., Ltd.) and 10 parts by weight of liquid paraffin are mixed to prepare an adhesive. After preparing and applying on the release paper to a thickness of 30 μm, the pressure-sensitive adhesive layer is placed on the back surface of the polyethylene terephthalate film of the base sheet and pressed with a 2 kg / 10 cm width roll, and the pressure-sensitive adhesive is polyethylene terephthalate film. The adhesive sheet was obtained by laminating on top.

Example 2
In Example 1, as a polyolefin resin, 100 parts by weight of a mixture composed of 50 parts by weight of a linear low density polyethylene resin (Kernel KF281 manufactured by Nippon Polychem Co., Ltd.) and 50 parts by weight of reactor TPO (PER210E manufactured by Tokuyama Co., Ltd.) An embossed film having a thickness of 100 μm was produced in the same manner except that it was used.

  A two-component polyurethane adhesive (manufactured by Seiko Kasei Co., Ltd.) was applied to the adhesive surface (non-embossed surface) of this embossed film, dried, and then a polyethylene terephthalate film (Teijin DuPont Co., Ltd.) having a thickness of 3.5 μm. )) Was bonded to obtain a base sheet. Next, the same adhesive as in Example 1 was laminated on the back surface of the polyethylene terephthalate film of the base sheet in the same manner as in Example 1 to obtain an adhesive sheet.

Example 3
In Example 1, an embossed film having a thickness of 100 μm was produced in the same manner except that 100 parts by weight of a linear low-density polyethylene resin (Kernel KF281 manufactured by Nippon Polychem Co., Ltd.) was used as the polyolefin resin.

  A two-component polyurethane adhesive (manufactured by Seiko Kasei Co., Ltd.) is applied to the adhesive surface (non-embossed surface) of this embossed film, dried, and then a 1.8 μm thick polyethylene terephthalate film (Teijin DuPont Co., Ltd.) )) Was bonded to obtain a base sheet. Next, the same adhesive as in Example 1 was laminated on the back surface of the polyethylene terephthalate film of the base sheet in the same manner as in Example 1 to obtain an adhesive sheet.

Comparative Example 1
In Example 1, as a polyolefin resin, 100 parts by weight of a mixture composed of 50 parts by weight of a linear low density polyethylene resin (Kernel KF281 manufactured by Nippon Polychem Co., Ltd.) and 50 parts by weight of reactor TPO (PER210E manufactured by Tokuyama Co., Ltd.) An embossed film having a thickness of 100 μm was produced in the same manner except that it was used, and this film was used as a base sheet.

Comparative Example 2
In Example 1, an embossed film having a thickness of 100 μm was produced in the same manner except that 100 parts by weight of a linear low-density polyethylene resin (Kernel KF281 manufactured by Nippon Polychem Co., Ltd.) was used as the polyolefin resin.

  A two-component polyurethane adhesive (Seiko Kasei Co., Ltd.) was applied to the adhesive surface (non-embossed surface) of this embossed film, dried, and then a polyethylene terephthalate film (Teijin DuPont Co., Ltd.) having a thickness of 12 μm. ) Was bonded to obtain a base sheet. Next, the same adhesive as in Example 1 was laminated on the back surface of the polyethylene terephthalate film of the base sheet in the same manner as in Example 1 to obtain an adhesive sheet.

Comparative Example 3
In Example 1, an embossed film having a thickness of 100 μm was produced in the same manner except that 100 parts by weight of a random polypropylene resin (Jallomer PM620 manufactured by Nippon Polyolefin Co., Ltd.) was used as the polyolefin resin.

  A two-component polyurethane adhesive (manufactured by Seiko Kasei Co., Ltd.) is applied to the adhesive surface (non-embossed surface) of this embossed film, dried, and then a 1.8 μm thick polyethylene terephthalate film (Teijin DuPont Co., Ltd.) )) Was bonded to obtain a base sheet. Next, the same adhesive as in Example 1 was laminated on the back surface of the polyethylene terephthalate film of the base sheet in the same manner as in Example 1 to obtain an adhesive sheet.

Example 4
(Manufacture of base sheet)
A one-component polyester polyurethane adhesive (T-5265L-20, Hirono Chemical Co., Ltd.) was applied to the adhesive surface (non-embossed surface) of the embossed film having a thickness of 100 μm obtained in Example 1 using a gravure coater. After drying, a polyethylene terephthalate film (manufactured by Teijin DuPont Co., Ltd.) having a thickness of 4.5 μm was dry-laminated at a temperature of 130 ° C. to obtain a base sheet.

(Manufacture of adhesive sheet)
30 parts by weight of a styrene-isoprene-styrene block copolymer (Califlex TR-1107 manufactured by Shell Chemical Co., Ltd.), 35 parts by weight of a terpene resin (YS resin manufactured by Yasuhara Chemical Co., Ltd.) and 10 parts by weight of liquid paraffin are mixed to prepare an adhesive. After preparing and applying on the release paper to a thickness of 30 μm, the pressure-sensitive adhesive layer is placed on the back surface of the polyethylene terephthalate film of the base sheet and pressed with a 2 kg / 10 cm width roll, and the pressure-sensitive adhesive is polyethylene terephthalate film. The adhesive sheet was obtained by laminating on top.

Example 5
A one-component polyester polyurethane adhesive (T-5265L-20 manufactured by Hirono Chemical Co., Ltd.) was applied to the adhesive surface (non-embossed surface) of the embossed film having a thickness of 100 μm obtained in Example 2 using a gravure coater. After drying, a polyethylene terephthalate film (manufactured by Teijin DuPont Co., Ltd.) having a thickness of 4.5 μm was dry-laminated at a temperature of 130 ° C. to obtain a base sheet.

  Next, the same adhesive as in Example 1 was laminated on the back surface of the polyethylene terephthalate film of the base sheet in the same manner as in Example 1 to obtain an adhesive sheet.

Example 6
A one-component polyester polyurethane adhesive (T-5265L-20, Hirono Chemical Co., Ltd.) was applied to the adhesive surface (non-embossed surface) of the embossed film having a thickness of 100 μm obtained in Example 1 using a gravure coater. After drying, a polyethylene terephthalate film (manufactured by Teijin DuPont Co., Ltd.) having a thickness of 4.5 μm was dry-laminated at a temperature of 130 ° C. to obtain a base sheet.

  Next, the same adhesive as in Example 1 was laminated on the back surface of the polyethylene terephthalate film of the base sheet in the same manner as in Example 1 to obtain an adhesive sheet.

Comparative Example 4
In Example 1, an embossed film having a thickness of 100 μm was produced in the same manner except that 100 parts by weight of a linear low density polyethylene resin (Kernel KF281 manufactured by Nippon Polychem Co., Ltd.) was used as the polyolefin resin. A one-component polyester polyurethane adhesive (T-5265L-20 manufactured by Hirono Chemical Co., Ltd.) was applied to the adhesive surface (non-embossed surface) using a gravure coater and dried.

  A 12 μm thick polyethylene terephthalate film (manufactured by Teijin DuPont Co., Ltd.) was dry-laminated at a temperature of 130 ° C. to obtain a base sheet. Next, the same adhesive as in Example 1 was laminated on the back surface of the polyethylene terephthalate film of the base sheet in the same manner as in Example 1 to obtain an adhesive sheet.

Comparative Example 5
In Example 1, an embossed film having a thickness of 100 μm was produced in the same manner except that 100 parts by weight of a random polypropylene resin (J-Allomer PM620 manufactured by Nippon Polyolefin Co., Ltd.) was used as the polyolefin resin. A one-component polyester polyurethane adhesive (T-5265L-20 manufactured by Hirono Chemical Co., Ltd.) was applied to (non-embossed surface) using a gravure coater and dried.

  A 1.8 μm thick polyethylene terephthalate film (manufactured by Teijin DuPont Co., Ltd.) was dry-laminated at a temperature of 130 ° C. to obtain a base sheet. Next, the same adhesive as in Example 1 was laminated on the back surface of the polyethylene terephthalate film of the base sheet in the same manner as in Example 1 to obtain an adhesive sheet.

The pressure-sensitive adhesive sheet according to Comparative Example 1 uses only a film made of a polyolefin resin as a base sheet, and a pressure-sensitive adhesive is directly laminated on the base sheet, so that the base sheet is significantly swollen and flows into the base sheet. The bleeding of paraffin and tackifiers is also remarkable. The pressure-sensitive adhesive sheets according to Comparative Example 2 and Comparative Example 4 are not practical as skin patches because the polyethylene terephthalate film in the base sheet is too thick, hard, and lacks flexibility. Further, the pressure-sensitive adhesive sheets according to Comparative Example 3 and Comparative Example 5 are formed by bonding a polyethylene terephthalate film to a random polypropylene resin film as a base sheet, and a low-density polyethylene resin or reactor TPO) as a polyolefin resin component. It is hard to use and lacks flexibility, so it is not practical as a skin patch. In contrast, any of the pressure-sensitive adhesive sheets according to the present invention can be suitably used as a skin patch.

Claims (6)

(A) including at least one selected from a low-density polyethylene resin and an olefinic thermoplastic elastomer, the total of which is 90 to 100% by weight;
(B) 0 to 5% by weight of random polypropylene resin,
(C) A polyolefin resin film having a thickness of 50 to 200 μm made of a resin composition of 0 to 5% by weight of an ethylene-butylene random copolymer is adhered to a polyethylene terephthalate film having a thickness of 1.8 to 5 μm with an adhesive. A base sheet for a skin patch having a 10% modulus in a range of 5 to 35 N / 19 mm in width and width.   The base sheet for skin patches according to claim 1, wherein the polyolefin resin film is dry-laminated with a polyethylene terephthalate film using a polyurethane adhesive.   The base sheet for a skin patch according to claim 1 or 2, wherein the polyurethane adhesive is a one-component or two-component polyurethane adhesive.   The base sheet for skin patches according to claim 3, wherein the one-pack type or two-pack type polyurethane adhesive is a polyester polyurethane adhesive.   A skin patch comprising the substrate sheet according to any one of claims 1 to 4 and an adhesive layer containing a drug provided on the back surface of the polyethylene terephthalate film of the substrate sheet. 5. The method for producing a base sheet for skin patch according to claim 4, wherein a one-component or two-component polyurethane adhesive is applied to the polyolefin resin film, and then a polyethylene terephthalate film having a thickness of 10 [mu] m or less is dry-laminated. A method for producing a base sheet for a skin patch.