JP7770098B2 - Substrate for patch with non-aqueous adhesive body - Google Patents

Description

The present invention relates to a substrate that can provide a patch in which the non-aqueous paste is less likely to seep out to the backside and is less likely to sink.

Patches (e.g., plasters) are used that are applied to the human body to, for example, exert anti-inflammatory and analgesic effects, exert cosmetic cosmetic effects, or impart a warming or cooling sensation. These patches are made by coating or impregnating a substrate comprising a fiber sheet with a paste containing an adhesive and medicinal ingredients. Plasters, in particular, are used for long-term application on the human body, so the adhesive contained in the paste is a non-aqueous adhesive, such as a rubber-based adhesive with strong adhesive strength. In this application, pastes containing non-aqueous adhesives are referred to as non-aqueous pastes.

Substrates that can be used for patches containing aqueous or non-aqueous pastes are required to be resistant to the seepage of the paste to the back surface.
- Based on the knowledge that there is a proportional relationship between the air permeability and the ease with which the adhesive layer seeps out to the back surface, the value calculated by dividing the air permeability of the substrate provided with the fiber sheet by the thickness of the substrate (air permeability per unit thickness) is smaller than 431; and
- A configuration in which the thickness of the substrate provided with the fiber sheet is 0.48 mm or less, based on the knowledge that it is thin and difficult to peel off;
We proposed a substrate that satisfies both of these requirements.

Patent application No. 2019-110747 (claims, 0008-0012, etc.)

In patches comprising such a base material, the aqueous or non-aqueous paste is indeed less likely to bleed through to the backside. However, when a patch comprising a non-aqueous paste is prepared and stored, partial sinking of the non-aqueous paste may occur on the main surface of the non-aqueous paste in the stored patch. In particular, when stored in a high-temperature environment, sinking of the non-aqueous paste is more likely to occur.
Initially, it was thought that the sunken areas of the non-aqueous paste were caused by the non-aqueous paste seeping through to the back surface. However, just because a patch has sunken areas of the non-aqueous paste does not necessarily mean that the non-aqueous paste will seep through to the back surface. Therefore, in order to provide a patch that is less likely to have sunken areas of the non-aqueous paste, it was thought that it would be necessary to find a new configuration that could prevent the occurrence of sunken areas of the non-aqueous paste and to optimize that configuration.

In light of the above, the present invention aims to provide a substrate for a patch comprising a non-aqueous paste, which comprises a fiber sheet and is capable of providing a patch in which the non-aqueous paste is less likely to seep out to the backside and in which areas where the non-aqueous paste is less likely to sink.

The first invention is a hydroentangled nonwoven fabric including crimped fibers as constituent fibers ,
The thickness is greater than 0.20 mm, and the air permeability is 61 cm ³ /cm ² /sec or more and less than 154 cm ³ /cm ² /sec.
"A substrate for a patch comprising a non-aqueous paste (however, excluding those comprising a hydroentangled nonwoven fabric in which the constituent fibers contain crimped fibers and in which the crimping of the latent crimped fibers is expressed by heat treatment using water vapor) ."

The applicant of the present application has developed a substrate for a patch, which is a substrate having a fiber sheet and a non-aqueous paste applied thereto, comprising:
- The thickness of the substrate is greater than 0.20 mm, so that a patch can be provided in which the non-aqueous paste is less likely to seep out to the back surface, and
When the air permeability of the base material is less than 154 cm ³ /cm ² /sec., it is possible to provide a patch in which the non-aqueous paste is less likely to sink into portions,
found.
Therefore, by using a substrate that satisfies the above-mentioned configuration of the present invention, it is possible to provide a patch in which the non-aqueous paste is less likely to seep out to the back surface and in which sunken portions of the non-aqueous paste are less likely to occur.

In the present invention, various configurations can be selected as appropriate, such as the configurations below. Note that, unless otherwise specified, the various measurements described in the present invention were performed under normal pressure and a temperature condition of 25°C. Furthermore, unless otherwise specified, the various measurement results described in the present invention were measured to a value one decimal place smaller than the desired value, and the desired value was calculated by rounding off the value. As a specific example, if the desired value is to one decimal place, the value was measured to two decimal places, and the obtained value was rounded off to one decimal place to calculate the desired value, and this value was used as the desired value. Furthermore, the upper and lower limit values exemplified in the present invention can be combined in any combination.

The substrate for a patch comprising a non-aqueous adhesive base according to the present invention (hereinafter sometimes simply referred to as "substrate") comprises a fiber sheet.
The fiber sheet referred to in the present invention refers to a sheet-like fiber assembly, such as a fiber web (e.g., a crosslay web, a parallel lay web, a crisscrosslay web, or a random web), a nonwoven fabric, or a woven or knitted fabric. Because the substrate of the present invention contains a fiber sheet, it is breathable, preventing stuffiness, and is flexible, allowing for excellent conformability to the human body, making it easy to provide a patch with an excellent application feel. Fiber sheets (particularly nonwoven fabrics), in which all constituent fibers are randomly entangled, are more flexible, and therefore a substrate comprising a nonwoven fabric is preferred. Furthermore, since the substrate comprises a fiber sheet, the entire surface has voids formed by the fibers surrounding each other. Portions of the nonaqueous paste enter these voids, providing anchoring properties, which facilitate the function of preventing the nonaqueous paste from remaining on the human body when the patch is removed.

The fibers constituting the fiber sheet may be, for example, polyolefin resins (e.g., polyethylene, polypropylene, polymethylpentene, polyolefin resins in which part of the hydrocarbon is substituted with a nitrile group or a halogen such as fluorine or chlorine), styrene resins, polyvinyl alcohol resins, polyether resins (e.g., polyether ether ketone, polyacetal, modified polyphenylene ether, aromatic polyether ketone), polyester resins (e.g., polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycarbonate, polyarylate, wholly aromatic polyester resins), polyimide resins, etc. It can be constructed using known resins such as polyamide-imide resin, polyamide-based resin (e.g., aromatic polyamide resin, aromatic polyetheramide resin, nylon resin, etc.), resins containing nitrile groups (e.g., polyacrylonitrile, etc.), urethane-based resin, epoxy-based resin, polysulfone-based resin (e.g., polysulfone, polyethersulfone, etc.), fluorine-based resin (e.g., polytetrafluoroethylene, polyvinylidene fluoride, etc.), cellulose-based resin, polybenzimidazole resin, acrylic-based resin (e.g., polyacrylonitrile-based resin copolymerized with acrylic acid ester or methacrylic acid ester, modacrylic-based resin copolymerized with acrylonitrile and vinyl chloride or vinylidene chloride, etc.).

To prevent the medicinal ingredients and non-aqueous adhesive contained in the non-aqueous plaster from being absorbed by the constituent fibers of the fiber sheet, the constituent fibers of the fiber sheet preferably contain polyolefin resin or polyester resin, and more preferably the constituent fibers of the fiber sheet are composed solely of polyolefin resin or polyester resin.

These resins may be either linear or branched polymers, and may be block or random copolymers. There are no particular limitations on the three-dimensional structure or the presence or absence of crystallinity of the resin. Furthermore, they may also be mixtures of multiple resin components.

In addition to the resins mentioned above, the constituent fibers may also contain additives such as flame retardants, fragrances, pigments, antibacterial agents, antifungal materials, photocatalytic particles, emulsifiers, dispersants, surfactants, and thickeners. They may also be dyed fibers containing pigments.

The constituent fibers can be obtained by known methods, such as melt spinning, dry spinning, wet spinning, direct spinning (melt-blowing, spunbonding, electrostatic spinning, etc.), methods of extracting fibers with a small diameter by removing one or more resin components from composite fibers, and methods of beating fibers to obtain split fibers.

The constituent fibers may be composed of one type of resin or multiple types of resins. Fibers composed of multiple types of resins are generally called composite fibers, and can be in various forms, such as core-sheath, sea-island, side-by-side, orange, and bimetal types.

The constituent fibers may also include irregular cross-section fibers in addition to roughly circular and elliptical fibers. The irregular cross-section fibers may have a cross section that is hollow, polygonal such as triangular, alphabetic such as Y-shaped, irregular, multi-lobed, symbolic such as asterisk, or a combination of multiple of these shapes.

It is preferable for the fiber sheet to contain elastic fibers as its constituent fibers, as these are more flexible and have excellent elasticity, allowing for better conformability to the human body and making it easier to provide a patch with an excellent application feel. Examples of such elastic fibers include fibers containing elastomers that are highly extensible, and crimped fibers in which the latent crimp of latent crimped fibers has been expressed.

Furthermore, it is preferable that the elastic fibers do not contain elastomers so that the medicinal ingredients and non-aqueous adhesive contained in the non-aqueous plaster base are not easily absorbed. From this perspective, it is preferable to use elastic fibers that are formed by the expression of crimps in latent crimp fibers composed only of polyolefin resin or polyester resin.

When the fiber sheet contains heat-fusible fibers as constituent fibers, the fibers can be heat-fused together to impart strength and dimensional stability to the substrate. Such heat-fusible fibers may be fully fusible, or partially fusible, such as the composite fibers described above. The component (resin) that exhibits heat-fusible properties in the heat-fusible fibers can be appropriately selected and used, such as heat-fusible fibers containing low-melting-point polyolefin resins or low-melting-point polyester resins.

When the fiber sheet is a fiber web or nonwoven fabric, it can be prepared by, for example, a dry method in which the above-mentioned fibers are fed into a carding device or air-laying device to entangle the fibers; a wet method in which the fibers are dispersed in a solvent and then entangled into a sheet; or a direct spinning method (such as a melt-blowing method, a spunbonding method, an electrospinning method, or a method in which a spinning solution and a gas stream are ejected in parallel to spin the fibers (e.g., the method disclosed in JP 2009-287138 A)) in which the fibers are spun and collected.

A nonwoven fabric can be prepared by entangling and/or integrating the constituent fibers of the prepared fiber web. Examples of methods for entangling and/or integrating the constituent fibers include entanglement using needles or water jets, and methods in which the fiber web is subjected to heat treatment, etc., to bond or melt the constituent fibers together using a binder or adhesive fiber.

Even for patches with a non-aqueous adhesive base that has strong adhesive strength, it is preferable to use a hydroentangled nonwoven fabric as the substrate, so as to provide a patch that is less likely to experience delamination when removed from the body.

The heat treatment method can be selected as appropriate, but examples include heating or heating and pressurizing with a roll, heating in a heater such as an oven dryer, far-infrared heater, dry heat dryer, or hot air dryer, and heating the resin contained therein by irradiating it with infrared rays without pressure.

A binder may be used to bond the fibers that make up the fiber sheet. Usable binders are selected as appropriate, but examples include polyolefins (such as modified polyolefins), ethylene-vinyl alcohol copolymers, ethylene-acrylate copolymers such as ethylene-ethyl acrylate copolymers, various rubbers and their derivatives (such as styrene-butadiene rubber (SBR), fluororubber, urethane rubber, and ethylene-propylene-diene rubber (EPDM)), cellulose derivatives (such as carboxymethyl cellulose (CMC), hydroxyethyl cellulose, and hydroxypropyl cellulose), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyvinylpyrrolidone (PVP), epoxy resins, polyvinylidene fluoride (PVdF), vinylidene fluoride-hexafluoropropylene copolymers (PVdF-HFP), acrylic resins (such as acrylic ester resins and acrylonitrile-styrene copolymer resins), and polyurethane resins.

In addition to the resins mentioned above, the binder may also contain additives such as flame retardants, fragrances, pigments, antibacterial agents, antifungal materials, photocatalytic particles, emulsifiers, dispersants, surfactants, and thickeners. However, since a substrate with excellent elasticity provides excellent flexibility and elasticity, making it easier to provide a patch with an excellent fit to the human body and a comfortable application, it is preferable that the fiber sheet constituting the substrate is not bonded to itself by heat-fusible fibers or a binder. A preferred method of providing such a preferred substrate is, for example, a substrate comprising a fiber sheet in which the constituent fibers are simply entangled with each other using a needle or a water jet.

When the fiber sheet is a woven or knitted fabric, the woven or knitted fabric can be prepared by weaving or knitting the fibers prepared as described above. In addition to fiber webs, fiber sheets such as nonwoven fabrics or woven or knitted fabrics may also be subjected to the above-mentioned method of entangling and/or integrating the constituent fibers.

The fineness and fiber length of the constituent fibers of the fiber sheet are not particularly limited, but in order to provide a patch with excellent application comfort, such as excellent conformability to the human body due to excellent flexibility and stretchability, the fineness is preferably 0.6 to 6.6 dtex, more preferably 0.9 to 5.5 dtex, and even more preferably 1.2 to 4.4 dtex. Furthermore, the fiber length is preferably 20 mm or more, more preferably 25 mm or more, and even more preferably 30 mm or more. On the other hand, if the fiber length exceeds 110 mm, fiber clumps tend to form during preparation of the fiber sheet, which may make it difficult to provide a patch with excellent application comfort. Therefore, the length is preferably 110 mm or less, and more preferably 60 mm or less. The above-mentioned lower and upper limits can be combined arbitrarily as desired. "Fiber length" refers to the value measured in accordance with JIS L1015 (2010), 8.4.1c) direct method (method C).

The substrate may contain other materials in addition to the fiber sheet described above (for example, fabric, porous film, or breathable foam). However, as described above, it is preferable for the substrate to be composed solely of a fiber sheet, as this makes it easier to provide a patch that provides an excellent application feel, such as preventing stuffiness and providing excellent conformability to the human body.

The substrate of the present invention has a thickness of more than 0.20 mm so as to provide a patch in which the non-aqueous paste is less likely to ooze out to the backside. In other words, the thicker the substrate, the more likely it is that the non-aqueous paste will ooze out to the backside. Therefore, the thickness of the substrate is preferably 0.25 mm or more, more preferably 0.30 mm or more, and even more preferably 0.33 mm or more. The upper limit of the substrate thickness is not particularly limited, but a thickness of 5 mm or less is practical because it facilitates providing a patch with excellent adhesion to the human body during application and other benefits. In the present invention, "thickness" refers to the arithmetic average of thicknesses measured in the load region in the thickness direction of the main surface of the substrate, where a load of 0.98 N (=100 gf) ^per 5 cm2 is applied, at five randomly selected locations. Such thickness measurements can be carried out, for example, using a high-precision digital length measuring machine (Litematic (registered trademark), manufactured by Mitutoyo Corporation).

Furthermore, the base material of the present invention has an air permeability of less than 154 cm ³ /cm ² /sec., so that a patch in which the non-aqueous paste is unlikely to sink into any part can be provided.

As a result of research, the applicant has discovered that the problem of partial sinking of the non-aqueous paste onto the main surface of a patch containing a non-aqueous paste when it is stored (a problem that is particularly likely to occur when a patch containing a non-aqueous paste is stored in a high-temperature environment) occurs when the non-aqueous adhesive, such as a rubber-based adhesive contained in the non-aqueous paste, softens, increasing the fluidity of the non-aqueous paste, causing it to unintentionally flow from the surface of the substrate toward the interior of the substrate.

Furthermore, as a result of investigations, the applicant of the present application has found that by adjusting the air permeability of the base material, specifically by adjusting the air permeability of the base material to less than 154 cm ³ /cm ² /sec., it is possible to prevent the non-aqueous paste base with increased fluidity from unintentionally flowing from the surface of the base material into the base material.

In other words, the lower the air permeability of the substrate is, less than 154 cm ³ /cm ² /sec., the more the non-aqueous adhesive with increased fluidity can be prevented from unintentionally flowing from the surface of the substrate into the interior of the substrate, even when the non-aqueous adhesive, such as a rubber-based adhesive, contained in the non-aqueous adhesive is softened. Therefore, the air permeability of the substrate is preferably 150 cm ³ /cm ² /sec. or less, more preferably 130 cm ³ /cm ² /sec. or less, more preferably 100 cm ³ /cm ² /sec. or less, and more preferably 95 cm ³ /cm ² /sec. or less. There is no particular restriction on the lower limit of the air permeability of the substrate, but since this makes it easy to provide a patch that is excellent in preventing stuffiness and conforming to the human body, and therefore has an excellent application feel, the air permeability of the substrate is preferably 0 cm ³ /cm ² /sec. A higher value is more realistic, and 10 cm ³ /cm ² /sec or more is preferable.

The "air permeability" in the present invention (unit: ^cm3 / ^cm2 ·sec.) is measured in accordance with JIS L1096:2010, 8.26.1 A method (Frazier method). That is, under the condition of a measurement area of 38 ^cm2 , the air flow rate is adjusted so that the pressure is 125 Pa, and the unit time and the air permeability per unit time at that time are measured. Such air permeability measurement can be carried out, for example, using a Frazier type air permeability tester (product number: FX3300) manufactured by TEXTESTAG. The unit of the thickness of the substrate is "mm".

Other configurations of the substrate, such as basis weight, other than the thickness and breathability of the substrate, are not particularly limited and are adjusted as appropriate. The basis weight of the substrate can be, for example, 10 to 200 g/ ^m2 , 20 to 180 g/ ^m2 , or 30 to 160 g/ ^m2 . The basis weight (unit: g/ ^m2 ) in the present invention can be determined by measuring the mass and area of one main surface of one or more test pieces taken from the substrate, and calculating the mass per 1 ^m2 of the test piece from the total mass of the test piece and the total area of one main surface.

The substrate of the present invention preferably has a breaking strength of 10 N/50 mm width or more in both the longitudinal and transverse directions, more preferably 15 N/50 mm width or more, and even more preferably 20 N/50 mm width or more, so as to prevent breakage when the patch is misapplied or removed after use. The upper limit of the breaking strength is not particularly limited, but in practice it is 300 N/50 mm width or less. This "breaking strength" is measured by taking a rectangular specimen 50 mm wide and 250 mm long from the substrate, pulling the specimen in the long direction using a constant-speed extension tensile tester (Tensilon, manufactured by Orientec Co., Ltd.), and measuring the maximum load until the specimen breaks. This maximum load is measured for three specimens, and the arithmetic average of these maximum loads is taken as the "breaking strength." The measurement is performed under conditions of a grip distance of 200 mm and a pulling speed of 500 mm/min.
In the present invention, the "longitudinal direction" refers to the production direction (flow direction) during production of the substrate, and the "lateral direction" refers to the direction perpendicular to the longitudinal direction, that is, the width direction.

The more stretchable the substrate of the present invention is, the better its adhesion to the skin and other objects will be. Therefore, the elongation percentage in both the longitudinal and transverse directions is preferably 15% or more, more preferably 20% or more, and even more preferably 25% or more. There is no particular upper limit to the elongation percentage, but in practice it is 300% or less.

This elongation (Sr, unit: %) refers to the percentage of the elongation of the sample piece at the maximum load (Smax, unit: mm) [= (length at the maximum load, unit: mm) - (grip spacing = 200 mm)] relative to the grip spacing (200 mm) when the breaking strength was measured as described above. In other words, it is a value obtained from the following formula. This measurement was carried out three times, and the arithmetic mean value of the percentages is defined as the elongation in the present invention.
Sr=(Smax/200)×100

To ensure that the substrate of the present invention is highly stretchable and adheres well to skin and other surfaces, the tensile strength at 50% elongation in both the longitudinal and transverse directions is preferably 20 N/50 mm width or less, more preferably 30 N/50 mm width or less, and even more preferably 20 N/50 mm width or less. In practice, the tensile strength at 50% elongation is 0.1 N/50 mm width or more. This tensile strength at 50% elongation is measured by taking a sample piece 50 mm wide and 250 mm long from the substrate, fixing the sample piece with a gripping distance of 200 mm using a constant-rate extension tensile tester (Tensilon, manufactured by Orientec Co., Ltd.), and measuring the load at the point where the sample is elongated by 100 mm (50%) (grip distance: 300 mm). This load measurement is performed on three sample pieces, and the arithmetic average of these loads is defined as the "tensile strength at 50% elongation." Measurements are performed at a tensile speed of 500 mm/min.

The substrate of the present invention preferably has a peel strength of 8.0 N/50 mm width or more, preferably 10.0 N/50 mm width or more, and preferably 15.0 N/50 mm width or more, so that even patches containing a non-aqueous adhesive base with strong adhesive strength are less likely to undergo delamination when removed from the human body. Peel strength can be determined by subjecting the substrate to the following measurement method.

(Method for measuring peel strength)
(1) Prepare an adhesive tape (for example, Sekisui Chemical Co., Ltd., product name: Vinycloth Tape No. 750, long side: 220 mm, short side: 50 mm) and overlap the adhesive tape over a range of 35 mm from one long side end toward the other long side end, with the adhesive surface interposed between them, to form a gripping portion, and prepare a measurement adhesive tape (long side: 185 mm, short side: 50 mm). Note that the exposed adhesive surface of the measurement adhesive tape has a long side of 150 mm and a short side of 50 mm, and the gripping portion has a length of 35 mm in the long side direction and a length of 50 mm in the short side direction. (2) Prepare six measurement adhesive tapes in the same manner.
(3) Three test pieces (long side: 150 mm, short side: 50 mm) are taken from the substrate, and the entire exposed adhesive surface of the measurement adhesive tape is attached to each of both main surfaces of each test piece. At this time, the measurement adhesive tapes are attached to the substrate so that the gripping portions of both measurement adhesive tapes attached to the test piece are the shortest distance from each other. In this way, a total of three laminates are prepared, each laminated in the order measurement adhesive tape-measurement object-measurement adhesive tape.
(4) The laminate is passed through a mangle machine (processing speed: 2.0 m/min., pressure: 2.0 kgf, number of processing times: 1), and pressure is applied between both main surfaces of the laminate.
(5) The gripping portions of both measurement adhesive tapes constituting the laminate are fixed to a fast-extension tensile tester (Tensilon, manufactured by Orientec Co., Ltd., distance between chucks at the start of measurement: 50 mm). Then, the measurement adhesive tapes are peeled off from the laminate until the total length between the chucks is 200 mm.
(6) Calculate the average strength values of the strength values measured when the length between the chucks described in item 5 is a total of 100 mm, a total of 120 mm, a total of 140 mm, and a total of 160 mm.
(7) The three prepared laminates are subjected to the above measurements, and the average of the strength values obtained is calculated. The average value thus calculated is the peel strength (unit: N/50 mm width) to be measured.

In addition, information such as the source, medicinal ingredients, and design may be printed on the substrate of the present invention. Furthermore, the substrate of the present invention may be colored with pigments or dyes.

The substrate can be used alone as a substrate for a patch containing a non-aqueous adhesive base, but it may also be laminated with a cover material, support, etc. to form a laminated substrate. Known cover materials and supports can be used, such as fabrics, porous films, and breathable foams. The laminated substrate may be simply made by stacking these materials, or it may be a laminated substrate made by bonding the layers together using a binder, hot melt web, or fiber adhesive, followed by an adhesive treatment such as heat sealing or ultrasonic welding.

The outer shape of the substrate can be adjusted as needed and is not particularly limited, but in addition to the shape of a raw sheet wound into a roll with a continuous length in the production direction, it can also be, for example, a square with rounded corners, a circle, or an oval. The substrate may also have cutouts, punched-out sections, or notches.

A patch can be prepared by applying a non-aqueous paste to at least one main surface of the substrate of the present invention. It is sufficient that the non-aqueous paste is present on the other main surface of the substrate. It may be present on only one main surface of the substrate, or it may be present on one main surface of the substrate and penetrate into the interior from that main surface.

The non-aqueous adhesive base of the present invention refers to an adhesive base containing a non-aqueous adhesive. While there are no particular limitations on the constituent materials, those with adhesive strength sufficient to fix the drug to the skin surface for an extended period of time at room temperature are preferred. Examples of non-aqueous adhesives include rubber-based adhesives, acrylic-based adhesives, and silicone-based adhesives. Among these, rubber-based adhesives are preferred from the standpoint of good adhesive properties and drug release, with natural rubber, synthetic isoprene rubber, polyisobutylene, polyvinyl ether, polyurethane, polyisoprene, polybutadiene, styrene-butadiene copolymer, styrene-isoprene copolymer, and styrene-isoprene-styrene block (SIS) copolymer being particularly preferred. These may be used alone or in combination.

The non-aqueous plaster can contain a medicinal ingredient. The type of ingredient is selected appropriately depending on the intended use of the patch, and is not particularly limited. For example, for patches intended for therapeutic purposes, functional ingredients can include antipyretic, analgesic, and anti-inflammatory agents, cardiac stimulants, vitamins, cardiac medications (vasodilators), bronchodilators, local anesthetics, antipruritics, drugs for suppurative diseases, and hormones. For patches intended for cosmetic purposes, functional ingredients that have a mild effect on the human body and are defined as quasi-drugs or cosmetics, such as cosmetic ingredients, can be included. For patches intended for a warming effect, functional ingredients can include capsicum extract and benzyl nicotinate, and for patches intended for a cooling effect, functional ingredients can include hydrogels and cooling agents such as menthol.

Examples of the present invention are described below, but the present invention is not limited to the following examples.

(Comparative Example 1)
A 100% by mass of latent crimped fiber A (fineness: 2.2 dtex, fiber length: 51 mm, cross-sectional shape: circular) composed only of polyester resin was fed to a carding machine to open the fibers, and the prepared fiber web was then fed to a hydroentanglement device, where water was applied to both main surfaces of the fiber web to entangle the constituent fibers.
The hydroentangled fiber web was then subjected to a hot air dryer to develop the latent crimp of the constituent fibers, forming a nonwoven fabric composed only of crimped fibers. The thickness of this nonwoven fabric was then adjusted by passing it through nip rolls to produce a substrate (basis weight: 81.4 g/m ² ).

Example 1
A substrate (basis weight: 89.0 g/m 2 ) was produced in the same manner as in Comparative Example 1, except that latent crimped fiber B (fineness: 1.3 dtex, fiber length: 44 mm, cross-sectional shape: ^circular ) composed only of polyester resin was used instead of latent crimped fiber A.

(Example 2, Comparative Example 2)
The nonwoven fabric of Comparative Example 1 was heat-pressed to have a predetermined thickness and breathability to produce two types of substrates.

(Example 3, Comparative Example 3)
The nonwoven fabric of Example 1 was heat-pressed to a predetermined thickness and breathability to produce two types of substrates.

In addition, the prepared substrates of the Examples and Comparative Examples were subjected to the following confirmation methods to evaluate the resistance to bleeding and the presence or absence of sinking in the patches prepared using these substrates.

(How to check the resistance to bleeding)
A non-aqueous paste containing the following composition was prepared.
SIS copolymer: 1.0 part by mass, polyisobutylene: 6.0 parts by mass, hydrogenated rosin ester: 7.5 parts by mass, liquid paraffin: 10.0 parts by mass, toluene: 50.0 parts by mass. A polyethylene terephthalate film having a silicone layer on one main surface was prepared, and the prepared non-aqueous paste was applied to the main surface on the silicone layer side. After application, it was allowed to dry at room temperature for 24 hours or more.
A polyethylene terephthalate film was laminated on one main surface of the substrate with a non-aqueous paste in between, to prepare a laminate. Three square samples, each 3 cm on a side, were then taken from the laminate.
A 6 kg glass plate was placed on the main surface of the collected sample on the polyethylene terephthalate film side for 10 minutes, thereby applying a load (6 kg/9 cm ² ) to each sample in the thickness direction.
Each sample thus pretreated was sealed in an aluminum pouch and subjected to an accelerated test for 5 days in a constant temperature and humidity chamber (temperature: 50° C., humidity: 30 RH%).
After the accelerated test, the main surface of the sample on which the substrate was exposed (the main surface of the substrate opposite to the side on which the non-aqueous paste was applied) was visually inspected and evaluated according to the following criteria.
◯: In all samples, no non-aqueous paste was present on the main surface where the substrate was exposed, and no bleeding occurred.
x: In one or more samples, a non-aqueous paste was present on the main surface where the substrate was exposed, and bleeding occurred.
Substrates rated as "○" in this confirmation method are substrates that can provide patches in which the non-aqueous paste is less likely to bleed to the backside, while substrates rated as "×" in this confirmation method are substrates in which it is difficult to provide patches in which the non-aqueous paste is less likely to bleed to the backside.

(How to check for subsidence)
After each sample was removed from the thermo-hygrostat prepared in the above-mentioned section (Method for confirming resistance to bleeding), the main surface of the nonaqueous plaster base applied to the substrate was observed from the side where the polyethylene terephthalate film was present using a stereomicroscope at a magnification of 10. The observation results were evaluated according to the following criteria.
◯: There were no areas on the main surface of the non-aqueous paste where the non-aqueous paste had partially sunk.
x: Partially sunk portions of the non-aqueous paste were present on the main surface of the non-aqueous paste.

The composition and physical properties of the substrates prepared for each Example and Comparative Example are summarized in Table 1. Items that were not measured are marked with a "-" in the table.

When the base materials prepared in Comparative Examples 2 and 3 were used, patches in which the non-aqueous paste was less likely to bleed through to the back side could not be provided. In contrast, when the base materials prepared in Comparative Example 1 and Examples 1 to 3 were used, patches in which the non-aqueous paste was less likely to bleed through to the back side could be provided. This is thought to be because the base materials prepared in Comparative Examples 2 and 3 were thin, at 0.20 mm or less, and the non-aqueous paste bled through to the back side, whereas the base materials prepared in Comparative Example 1 and Examples 1 to 3 were thicker, making the non-aqueous paste less likely to bleed through to the back side.

Furthermore, when the base material prepared in Comparative Example 1 was used, it was not possible to provide a patch in which sinking areas of the non-aqueous paste were less likely to occur. In contrast, when the base materials prepared in Examples 1 to 3 and Comparative Examples 2 and 3 were used, it was possible to provide patches in which sinking areas of the non-aqueous paste were less likely to occur. The reason for this is thought to be that the base material prepared in Comparative Example 1 had an air permeability of 154 cm ³ /cm ² /sec or more, and the nonwoven fabric had a coarse, sparse structure, so a patch in which sinking areas of the non-aqueous paste were less likely to occur was not provided, whereas the base materials prepared in Examples 1 to 3 and Comparative Examples 2 and 3 had lower air permeability, so the nonwoven fabric had a dense structure, so patches in which sinking areas of the non-aqueous paste were less likely to occur were provided.

Although the substrates prepared in Example 1 and Comparative Example 1 both had a thickness of 0.55 mm, when the substrate prepared in Example 1 was used, a patch in which the non-aqueous paste was less likely to sink into areas was provided, whereas when the substrate prepared in Comparative Example 1 was used, a patch in which the non-aqueous paste was less likely to sink into areas was not provided. These results demonstrate that there is no direct correlation between the thickness of the substrate and whether or not the substrate is capable of producing a patch in which the non-aqueous paste is less likely to sink into areas.

As a result, by using a substrate that satisfies the configuration of the present invention, it is possible to provide a patch in which the non-aqueous paste is less likely to seep out to the backside and in which areas where the non-aqueous paste is less likely to sink can be prevented.

By using a patch base material comprising the nonaqueous adhesive mass of the present invention, it is possible to provide patches (e.g., poultices, plasters, tape preparations, surgical tapes, taping materials and bandages, facial masks, warming sheets, and cooling sheets) that, for example, exert anti-inflammatory and analgesic effects, exert cosmetic cosmetic effects, or impart a warming or cooling sensation.

Claims (1)

The fabric is a hydroentangled nonwoven fabric containing crimped fibers as its constituent fibers ,
The thickness is greater than 0.20 mm, and the air permeability is 61 cm ³ /cm ² /sec or more and less than 154 cm ³ /cm ² /sec.
A substrate for a patch comprising a non-aqueous paste (excluding those comprising a hydroentangled nonwoven fabric in which the constituent fibers contain crimped fibers and the crimping of the latent crimped fibers is expressed by heat treatment using water vapor) .