Adhesive bandages and polyurethane nonwoven fabrics for adhesive bandages

Abstract

The present invention aims to provide a bandage such as a first aid bandage that has a support made of an ultrafine urethane nonwoven fabric with excellent breathability and elasticity, and that has a highly balanced range of required properties such as self-backing adhesion, drying properties, air permeability, and interlayer strength, by appropriately embossing the surface of the support. The present invention relates to a long, narrow adhesive bandage comprising an ultra-fine urethane nonwoven fabric embossed on one surface and an adhesive layer laminated on the surface opposite the embossed surface, characterized in that the ratio (y / x) of the 30% tensile load (x) in the short side direction of the adhesive bandage to the 30% tensile load (y) in the long side direction is 0.8 to 2.0, the water retention ratio per weight of the urethane nonwoven fabric is 0.8 or less, the adhesive strength of the adhesive bandage to a Bakelite plate is 5.0 to 8.0 N / 24 mm, and the adhesive strength of the adhesive bandage to the embossed surface (self-back adhesive strength) is 1.2 N / 24 mm or more.

Description

[Technical Field]

[0001] The present invention relates to adhesive bandages and polyurethane nonwoven fabrics for adhesive bandages, which are medical adhesive products used to protect affected areas and wounds and to fasten gauze, absorbent cotton, catheters, tubes, and patches to the skin. In particular, the present invention relates to first-aid bandages with wound protection pads that are used to protect, promote healing, and relieve pain from wounds such as cuts, abrasions, punctures, scratches, and blisters. [Background technology]

[0002] Generally, adhesive bandages have a structure in which an adhesive layer is provided on one side of a support made of paper, cloth, plastic film, etc. For example, soft vinyl chloride film is widely used as a support for first aid bandages because it has excellent toughness, stress relaxation, printability, etc., and is inexpensive. However, such plastic films do not fit well to the skin surface, and are also insufficient in flexibility and breathability.

[0003] In contrast, nonwoven fabrics have excellent breathability and are less likely to become stuffy when applied, making them suitable as a support for adhesive bandages, which are medical adhesive products. Furthermore, in recent years, elastic nonwoven fabrics made from polyurethane or polyester have been developed. By using these elastic and breathable nonwoven fabrics as a support for adhesive bandages, adhesive bandages can be obtained that are less likely to cause skin disorders such as rashes, itching, and erythema, and that can also follow the movements of the skin to which they are applied (see, for example, Patent Documents 1 and 2). In particular, adhesive bandages that use polyurethane nonwoven fabrics, which have excellent breathability and elasticity, as a support have various excellent properties (see, for example, Patent Documents 3 and 4). The applicants have previously proposed a roughly rectangular first aid adhesive bandage consisting of an adhesive tape with an adhesive applied to one side of a breathable and stretchable nonwoven fabric substrate, characterized in that (1) the nonwoven fabric is a polyurethane nonwoven fabric formed from ultrafine polyurethane filaments with an average fiber diameter of 7 to 15 μm, and the ratio (y / x) of the 50% tensile load (x) in the machine direction (MD) to the 50% tensile load (y) in the cross direction (CD) is in the range of 1.10 to 2.00, and (2) the roughly rectangular adhesive bandage is punched out with the long side aligned with the CD of the substrate and the short side aligned with the MD of the substrate. This first-aid adhesive bandage has a good fit with little discomfort, and is particularly advantageous in terms of cost because the basis weight of the nonwoven fabric can be kept low.When wrapped around a finger or the like, the bandage is neither too tight nor too loose, but just the right amount.Furthermore, unlike conventional products, when the temperature rises or the bandage is subjected to repeated stretching, the orientation relaxes, shrinking in the short axis direction but not stretching in the long axis direction, so it is less likely to become loose and slip off.In addition, peeling from the edges is suppressed when applied, it is breathable, does not interfere with skin breathing, and can suppress discomfort due to stuffiness and the growth of bacteria, among other excellent effects (see Patent Document 3).

[0004] Meanwhile, the technology of embossing nonwoven fabrics has been used for a long time, and Patent Documents 3 and 4 describe embossing of adhesive bandages and other medical adhesive tapes that use nonwoven fabric as a support. However, the effects of embossing conditions on the properties of adhesive bandages have not been fully investigated, and an adhesive bandage with a highly balanced range of properties has not yet been achieved. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2-14059 [Patent Document 2] Japanese Patent Application Publication No. 9-560 [Patent Document 3] Japanese Patent Application Publication No. 10-33585 [Patent Document 4] Japanese Patent Application Publication No. 11-9623 Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide a bandage such as a first aid bandage that has a support made of an ultrafine urethane nonwoven fabric that has excellent breathability and elasticity, and that has a highly balanced variety of required properties such as self-backing adhesion, drying properties, breathability, and interlayer strength, by appropriately embossing the surface of the support. [Means for solving the problem]

[0007] The present inventors have investigated further improvements to the invention of Patent Document 3, particularly the embossing conditions. As a result, they have found that depending on the strength of the embossing applied to the surface of an ultrafine polyurethane nonwoven fabric formed under specific conditions, some of the properties required for a bandage using the nonwoven fabric as a support tend to improve and others tend to decrease. Then, through detailed analysis and investigation of these results, they have found that by controlling the embossing conditions within a certain range, an excellent bandage can be obtained in which all of these properties fall within a range that is practically acceptable, and have completed the present invention. That is, the gist of the present invention is as follows.

[0008] [1] A long, narrow adhesive bandage made of an ultrafine urethane nonwoven fabric embossed on one surface and having an adhesive layer laminated on the surface opposite the embossed surface, characterized in that the ratio (y / x) of the 30% tensile load (x) in the short side direction of the adhesive bandage to the 30% tensile load (y) in the long side direction is 0.8 to 2.0, the water retention ratio per weight of the ultrafine urethane nonwoven fabric is 0.8 or less, the adhesive strength of the adhesive bandage to a Bakelite plate is 5.0 to 8.0 N / 24 mm, and the adhesive strength of the adhesive bandage to the embossed surface (self-back adhesive strength) is 1.2 N / 24 mm or more. [2] The adhesive bandage described in [1], characterized in that the breathability of the adhesive bandage is 10.0 sec / 100 mL or less. [3] A bandage according to [1] or [2], characterized in that the 30% tensile load (x) in the short side direction of the bandage is 2.0 to 4.0 N / 24 mm, and the 30% tensile load (y) in the long side direction of the bandage is 2.0 to 4.5 N / 24 mm. [4] A polyurethane nonwoven fabric for adhesive bandages, which is embossed on at least one surface, has a water retention ratio per weight of 0.8 or less, an air resistance value of 1.6 kPa·s / m or less, and a ratio (Y / X) of 30% tensile load in the machine direction (MD) (X) to 30% tensile load in the cross direction (CD) (Y) of 1.0 to 2.0. [5] The polyurethane nonwoven fabric for adhesive bandages according to [4], wherein X is 2.5 to 4.0 N / 24 mm and Y is 2.5 to 4.5 N / 24 mm. [6] Basis weight: 50-100g / m 2 The polyurethane nonwoven fabric for adhesive bandages according to [4] or [5], [Effects of the Invention]

[0009] According to the present invention, by embossing an ultrafine urethane nonwoven fabric formed under specific conditions under specific conditions, a bandage using the nonwoven fabric as a support can be made such that when wrapped around a finger or the like, the bandage is neither too tight nor too loose, but just tight enough, and is unlikely to loosen or slip off even after repeated stretching, and peeling from the edges is suppressed when applied.In addition, the self-back adhesive strength, water retention capacity (dryness), breathability, interlayer strength, etc. of the nonwoven fabric are within practically suitable ranges, resulting in an excellent bandage.In other words, the bandage of the present invention is excellent in flexibility and stretchability derived from the ultrafine urethane nonwoven fabric, 1. When the patch is wrapped around a finger or the like and applied with one end attached to the backing, the end does not easily peel off, even when manually applied. In addition, the interlayer strength of the backing is strong, so that when the end is peeled from the backing, the backing is not easily peeled off, which is unlikely to cause the problem of the adhesive layer remaining on the skin. 2. Even after doing water work or taking a bath, the patch quickly drains water (feels dry) and the skin where it is applied does not become too swollen. 3. On the other hand, embossing tends to reduce the breathability of the support, but when used as a bandage, this can be kept within a range that does not cause any particular problems in practical use, and the various properties required for a bandage are well balanced. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a graph showing the water retention rate per weight for each embossing depth level of a urethane nonwoven fabric. [Figure 2] FIG. 1 shows the results of a practical evaluation of the ease with which adhesive bandages dry after bathing at various embossing depth levels of urethane nonwoven fabric. [Figure 3] FIG. 10 is a graph showing the adhesive strength of the back surface of a urethane nonwoven fabric at various embossing depth levels. [Figure 4] This figure shows the results of a practical evaluation of the adhesion of the overlapping portion of the adhesive bandage just before peeling it off, at each embossing depth level of the urethane nonwoven fabric. DETAILED DESCRIPTION OF THE INVENTION

[0011] The adhesive bandage and polyurethane nonwoven fabric for adhesive bandage of the present invention will be described in detail below.

[0012] <Bandage> One embodiment of the adhesive bandage of the present invention is a long, narrow adhesive bandage (adhesive tape) having a support layer (a1) embossed on one side and comprising a nonwoven fabric formed from ultrafine urethane filaments, and a breathable adhesive layer (a2) laminated on the surface opposite the embossed surface. Another embodiment is a so-called first-aid adhesive bandage, which further comprises a pad layer (b) approximately in the center of the adhesive layer in a section of a given length of the adhesive bandage. This first-aid adhesive bandage may further comprise a release sheet (c). The support layer (a1), adhesive layer (a2), pad layer (b), and release sheet (c) that constitute the adhesive bandage of the present invention are described in detail below.

[0013] 1.Support layer (a1) The support layer includes a nonwoven fabric formed from ultrafine urethane filaments under specific conditions and embossed under specific conditions. In this specification, "a nonwoven fabric formed from ultrafine urethane filaments under specific conditions" and "a nonwoven fabric formed from ultrafine urethane filaments" are also simply referred to as "ultrafine urethane nonwoven fabric." The fiber diameter of the ultrafine urethane filaments used to form the ultrafine urethane nonwoven fabric of the present invention is preferably within the range of 7 to 25 μm, more preferably 10 to 18 μm. When such an ultrafine urethane nonwoven fabric is used as the support layer, a bandage can be obtained that has good strength, stretchability, and appearance, provides little discomfort when applied, and highly satisfies other required qualities such as breathability.

[0014] The ultrafine polyurethane nonwoven fabric of the present invention can be suitably obtained by melt-blowing a melt-spinnable thermoplastic polyurethane elastomer into a nonwoven fabric. The thermoplastic polyurethane elastomer is obtained by melt polymerization of raw materials including a polyol (e.g., polyhexamethylene diol), a diisocyanate (e.g., 4,4'-diphenylmethane diisocyanate), and a low-molecular-weight diol (e.g., 1,4-butanediol) that serves as a hard segment.

[0015] Examples of the polyol-based soft segment, which is a raw material for the thermoplastic polyurethane elastomer, include low-melting-point polyols having a number-average molecular weight of 500 to 6,000, such as dihydroxypolyether, dihydroxypolyester, dihydroxycarbonate, and dihydroxypolyesteramide. Polytetramethylene glycol is typically used as the polyether-based soft segment. Examples of diisocyanates include 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, 2,6-diisocyanatomethyl caproate, and hexamethylene diisocyanate. Examples of chain extenders (hard segments) include low-molecular-weight diols, amino alcohols, and triols.

[0016] In the melt-blowing method, a synthetic resin such as a thermoplastic elastomer is melted, the molten liquid is extruded from a nozzle-shaped die with many fine holes, and then blown away with high-speed heated gas. The resulting particles are then collected on a net conveyor to produce an ultrafine polyurethane nonwoven fabric. The endless net conveyor moves the ultrafine polyurethane nonwoven fabric in the machine direction (MD). The web collected on the net conveyor is pressed with a roller as needed and wound up as an ultrafine polyurethane nonwoven fabric. The ultrafine polyurethane nonwoven fabric produced by this manufacturing method generally has some degree of orientation in the machine direction (MD) of the product.

[0017] In the present invention, to orient the ultrafine filaments in the direction perpendicular to the machine direction (MD) of the product (cross direction: CD), a method is preferably employed for producing an ultrafine urethane nonwoven fabric by the melt-blowing process, in which a die is reciprocated in the cross direction (CD) and the speed of the net conveyor in the machine direction (MD) is adjusted to be slower than the speed of the die reciprocating in the width direction. The speed of the net conveyor in the machine direction (MD) is preferably 1 / 3 or less, more preferably 1 / 25 to 1 / 3, and particularly preferably 1 / 20 to 1 / 5, of the speed of the die reciprocating in the cross direction (CD). By employing such a production method, even when forming a nonwoven fabric from ultrafine filaments, an ultrafine urethane nonwoven fabric can be obtained that has the required strength, minimal thickness unevenness, and is oriented in the width direction. This production method also allows the ultrafine urethane nonwoven fabric to be easily torn by hand.

[0018] The embossing process for the ultrafine polyurethane nonwoven fabric can be carried out using known devices and methods. For example, the point heat pressing method can be used. By embossing, it is possible to obtain a 1 cm 2 Forming 10 or more heat-sealed points per microfine particle can also enhance the internal strength of the ultrafine particle nonwoven fabric. In the present invention, a large number of minute irregularities are formed on at least one side of the ultrafine particle nonwoven fabric that serves as a support by embossing. To form such minute irregularities, for example, it is preferable to use a method in which an embossing roll with an irregular pattern formed on its surface is placed opposite an anvil roll, the ultrafine particle nonwoven fabric is passed between the two rolls, and pressure-treated under heat.

[0019] Suitable conditions for embossing the ultrafine polyurethane nonwoven fabric are an embossing roller temperature of 80 to 150° C., a pressure (linear pressure) of 20 to 200 N / mm, and a processing speed of 5 to 20 m / min.

[0020] The embossed pattern applied to the ultrafine polyurethane nonwoven fabric is not particularly limited as long as it has a shape that creates numerous fine projections and depressions on at least one side of the ultrafine polyurethane nonwoven fabric. Examples include a grid pattern, a pattern with numerous short lines arranged in a staggered pattern, a pattern with numerous short lines arranged vertically and horizontally, and a pattern with numerous small circles. Among these embossed patterns, a grid pattern with numerous depressions defined by intersecting ridges (protrusions) is preferred. The ridge line width is preferably 50 to 600 μm, the ridge line spacing (depression width) is preferably 0.5 to 1.5 mm, and the depression depth is preferably 50 to 600 μm. The total area of ​​the protrusions (ridges, etc.) raised on the back surface of the ultrafine polyurethane nonwoven fabric serving as a support is usually 50% or less, preferably 40% or less, more preferably 30% or less, even more preferably 20% or less, and particularly preferably 10% or less of the total area of ​​the ultrafine polyurethane nonwoven fabric. The total area of ​​the recesses is preferably about 5% or more, more preferably about 10% or more, and even more preferably about 20% or more.

[0021] The ultrafine urethane nonwoven fabric usually has a basis weight of 40 to 120 g / m 2 and 50-100g / m 2 It is preferable that the density is 60 to 100 g / m 2 It is more preferable that the thickness is within the range of 0.8 or less. The thickness of the ultrafine urethane nonwoven fabric is usually about 100 to 500 μm. Furthermore, the water retention ratio per weight of the ultrafine urethane nonwoven fabric is preferably 0.8 or less, and more preferably 0.75 or less. Here, the water retention ratio per weight is determined by immersing ultrafine urethane nonwoven fabric cut to a certain size in water for 30 minutes, then removing it with tweezers and shaking it two or three times to remove water (until no water droplets are dripping). The water retention ratio per weight is then calculated using the following formula: (Weight after draining - Weight before immersion) / Weight before immersion

[0022] If the water retention ratio per weight of the ultrafine urethane nonwoven fabric exceeds 0.8, the drying properties of the adhesive bandage after bathing or working in water will be poor, and the skin at the application site will become swollen, leading to discomfort. On the other hand, there is no particular lower limit, and a small amount of water retention is more preferable because it dries quickly.

[0023] In the present invention, the airflow resistance of the support (the ultrafine urethane nonwoven fabric after embossing) is 1.6 kPa·s / m or less, and preferably 1.3 kPa·s / m or less. 2 0.1 to 1.6 kPa·s / m, basis weight 50 to 100 g / m 2 0.25~1.3kPa·s / m, basis weight 60~100g / m 2 It is preferable that the value obtained by dividing the air resistance value by the basis weight (air resistance value / basis weight) is in the range of 0.4 to 1.3 kPa·s / m when the basis weight is 40 g / m. 2 More than 60g / m 2 If it is less than 60g / m, it is within the range of 0.0040~0.0160. 2 More than 100g / m 2 In the following cases, it is preferable that the value is within the range of 0.0075 to 0.0170. If the air flow resistance value of the support is below the above range, the interlayer strength of the support will be insufficient and interlayer delamination will be more likely to occur. On the other hand, if the air flow resistance value exceeds the above range, the adhesive bandage will be prone to becoming stuffy when applied to human skin.

[0024] In the support of the present invention, the ratio of 30% tensile load in MD (X) to 30% tensile load in CD (Y) (Y / X) is 0.5 to 3.0, preferably 1.0 to 2.0, due to the ultrafine urethane nonwoven fabric being oriented in the cross direction (CD) during film formation. Furthermore, X is 1.0 to 5.0 N / 24 mm, preferably 2.5 to 4.0 N / 24 mm, and Y is 1.0 to 5.0 N / 24 mm, preferably 2.5 to 4.5 N / 24 mm.

[0025] In addition, pigments or dyes for coloring the ultrafine polyurethane nonwoven fabric to skin color or the like, antistatic agents, lubricants, etc. can be added to the polyurethane melt to form a film within a range that does not impair the effects of the present invention.

[0026] 2. Adhesive layer (a2) The adhesive bandage of the present invention has a structure in which an adhesive layer is laminated on the surface opposite to the embossed surface of the support layer (a1). The adhesive in this adhesive layer (a2) may be an acrylic adhesive, a rubber adhesive, a silicone adhesive, or the like, but those with little skin irritation are preferred.

[0027] Examples of acrylic adhesives include homopolymers or copolymers of long-chain (meth)acrylic acid ester monomers having approximately 4 to 12 carbon atoms, such as butyl acrylate, 2-ethylhexyl acrylate, and isononyl acrylate; or copolymers obtained by copolymerizing a (meth)acrylic acid ester monomer as the main component with 2 to 50 wt% of one or more other copolymerizable monomers, such as (meth)acrylic acid, vinyl acetate, styrene, vinylpyrrolidone, acrylamide, hydroxyethyl acrylate, and hydroxypropyl acrylate. Acrylic adhesives may be solvent-based, obtained by polymerizing the monomer in an organic solvent, such as toluene, hexane, or ethyl acetate, using a peroxide, such as benzoyl peroxide, as an initiator under a nitrogen atmosphere, or emulsion-based, obtained by emulsifying and dispersing the monomer in water with an emulsifier and then polymerizing it. After polymerization, it is preferable to crosslink the polymer by adding an appropriate amount of a multifunctional resin, such as an epoxy resin, before coating the polymer on a sheet or film substrate.

[0028] Examples of rubber-based adhesives include compositions in which a tackifier resin, a softener, etc. are blended with a rubber base such as synthetic polyisoprene rubber or a styrene-isoprene-styrene block copolymer.

[0029] The adhesive layer (a2) in the adhesive bandage of the present invention is preferably a breathable adhesive layer (a2). The breathable adhesive layer (a2) is an adhesive having an air permeability of 20 seconds / 100 mL or less, measured in accordance with JIS-P8117 using a Gurley densometer (Tester Sangyo Co., Ltd.). The air permeability of the adhesive layer (a2) is preferably 10 seconds / 100 mL or less, more preferably 5 seconds / 100 mL or less, and even more preferably 1 second / 100 mL or less. Since the air permeability of the adhesive layer (a2) itself cannot be measured, the air permeability of the adhesive layer (a2) is determined by measuring the air permeability of the adhesive layer (a2) laminated to a material with air permeability equal to or greater than that of the adhesive layer (a2), such as a nonwoven fabric or woven fabric. The air permeability of the adhesive layer (a2) is measured specifically as follows. Specifically, an adhesive bandage (A) (comprising a support layer (a1) and an adhesive layer (a2)) cut to a size of 50 mm x 50 mm was used. ] is attached to the clamping plate (base). The area that passes through the clamping plate is 645.16 mm 2 The inner cylinder of the Gurley densometer is pulled out and set on the stopper, and the test specimen is clamped between the clamping plates. The inner cylinder is gently lowered, and the number of seconds it takes for 100 mL of air to pass through is measured. This is the air permeability of the adhesive layer (a2) (seconds / 100 mL). Therefore, the particularly preferred air permeability of the adhesive bandage (A) is 0.2 to 10.0 seconds / 100 mL.

[0030] By using a breathable adhesive layer (a2) as the adhesive layer in the adhesive bandage of the present invention, the breathability and cushioning properties of the adhesive layer and the adhesive bandage are improved, and the conformability to the skin is improved, resulting in good adhesion to the skin.

[0031] The expansion ratio of the breathable pressure-sensitive adhesive layer (a2) is usually in the range of 1.1 to 10 times, preferably 1.2 to 8 times, more preferably 1.5 to 6 times, and even more preferably 2 to 5 times. The density of the breathable pressure-sensitive adhesive layer (a2) is usually 0.1 to 0.9 g / cm. 3 , preferably 0.12 to 0.8 g / cm 3 , more preferably 0.15 to 0.6 g / cm 3 , more preferably 0.2 to 0.5 g / cm3 The range is.

[0032] The breathable adhesive layer (a2) is usually provided over the entire surface of one side of the support layer (a1), but if desired, it can be provided only on a part of the support layer (a1) rather than over the entire surface, as long as it does not adversely affect the adhesive strength.

[0033] The thickness of the breathable pressure-sensitive adhesive layer (a2) is not particularly limited, but is usually in the range of 10 to 200 μm, preferably 15 to 150 μm, and more preferably 20 to 100 μm.

[0034] The adhesive strength of the breathable adhesive layer (a2) is adjusted to be preferably within the range of 1.0 to 10 N / 24 mm, more preferably 5.0 to 8.0 N / 24 mm, in terms of adhesive strength (peeling strength) to a Bakelite plate.

[0035] The breathable pressure-sensitive adhesive layer (a2) of the present invention can be obtained by a conventional method. Specifically, a pressure-sensitive adhesive is mixed with a physical blowing agent such as air, nitrogen gas, or carbon dioxide gas, or a decomposition-type chemical blowing agent, and then coated on a release paper. Alternatively, the pressure-sensitive adhesive is coated on a release paper that has previously been coated or sprayed with an aqueous solution or organic solvent, followed by heating to utilize the foaming or vaporization effect. Other methods include a method in which atomized water is applied to the coated, undried pressure-sensitive adhesive surface to form fine pores, and a method in which the pressure-sensitive adhesive is ejected onto the release paper in the form of threads or fibers. These methods form a pressure-sensitive adhesive layer with numerous fine pores. Among these methods, the foaming method is preferred from the viewpoint of forming fine and uniform pores.

[0036] 3. Pad layer (b) The adhesive bandage of the present invention may also include a pad layer (b). In the present invention, the pad layer (b) is a layer provided to provide functions such as hemostasis and protection of the affected area when the adhesive bandage is applied to the affected area. Typically, gauze, nonwoven fabric, woven fabric, knitted fabric, compressed fiber, hydrocolloid, or other absorbent materials are used. However, depending on the area of ​​use, a thin film of polyethylene or other plastic may be applied to the upper surface of the above materials to prevent body fluids from adhering to the affected area. Furthermore, the pad layer (b) may hold disinfectants, therapeutic drugs, and other medications, as needed. The size of the pad layer (b) is typically in the range of 5% to 70%, preferably 10% to 50%, and more preferably 15% to 40%, of the total area of ​​the adhesive bandage (100%).

[0037] 4.Release sheet (c) The adhesive bandage of the present invention typically further comprises a release sheet (c). The release sheet (c) is laminated on the surface of the breathable adhesive layer (a2) opposite the support layer (a1) containing the ultrafine urethane nonwoven fabric. The release sheet (c) can be a sheet commonly used in the field of adhesive bandages, such as a paper substrate such as high-quality paper or glassine paper, or a polyester film, which has been treated with a release agent. The release sheet (c) may be of a size and shape sufficient to cover the entire bandage, or may be larger than the area of ​​the bandage. The release sheet (c) may also be divided into two or more sheets, and at least one of the two or more divided release sheets (c) may have a folded portion. Furthermore, a total of three or more divided release sheets (c) may be provided, including one release sheet (c) covering at least a portion of the pad layer (b), and two or more release sheets (c) arranged on the bandage and breathable adhesive layer (a2) around the pad layer.

[0038] 5. Characteristics of Bandage (A) The adhesive bandage of the present invention comprises an elongated laminate in which a support layer (a1) made of an ultrafine urethane nonwoven fabric embossed on one side is laminated with a breathable adhesive layer (a2) on the side opposite the embossed side.

[0039] The ratio (y / x) of the 30% tensile load (x) of the elongated bandage, measured along the short side in the machine direction (MD) of the original roll, to the 30% tensile load (y) of the elongated bandage, measured along the long side in the cross direction (CD) of the original roll, is within the range of 0.5 to 3.0, preferably within the range of 0.8 to 2.0. x is 1.0 to 5.0 N / 24 mm, preferably 2.0 to 4.0 N / 24 mm. y is 1.0 to 5.0 N / 24 mm, preferably 2.0 to 4.5 N / 24 mm. By keeping each value within this range, when wrapped around a finger or the like, the bandage is neither too tight nor too loose, but is just right. Even with repeated stretching and contraction, it is unlikely to loosen or slip off, and peeling from the edges is suppressed when applied.

[0040] The adhesive strength of the adhesive bandage (A) to a Bakelite plate is 5.0 to 8.0 N / 24 mm, preferably 6.5 to 8.0 N / 24 mm. The adhesive strength of the adhesive bandage (A) to the embossed surface of the support (self-backside adhesive strength) is 1.2 N / 24 mm or more, preferably 1.3 N / 24 mm or more. The adhesive strength of the adhesive bandage to a Bakelite plate is measured in accordance with JIS-Z0237. The adhesive strength of the adhesive bandage to the embossed surface of the support (self-backside adhesive strength) is measured by attaching a 24 mm wide, 100 mm long piece of adhesive bandage to a Bakelite plate, and then attaching the adhesive side of a 24 mm wide, 240 mm long piece to the backside of the embossed surface of the support with both ends aligned and overlapping. A 50 g load is applied once, and the peel force from the backside of the piece in a 180-degree direction is measured using a tensile tester at a pulling rate of 300 mm / min.

[0041] If the adhesive strength of the adhesive bandage (A) to the Bakelite plate is less than 5.0, the adhesive strength to the skin during application is weak, causing peeling due to friction with clothing, or when applied to flexed or extensible parts such as joints, the bandage may lift off from the skin during application. On the other hand, if the adhesive strength exceeds 8.0, peeling is unlikely to occur during application, but the keratin at the application site tends to be torn off, causing pain when peeling. Furthermore, if the adhesive strength to the back surface is less than 1.2, when the bandage is wrapped around a finger or the like and applied with one end attached to the back surface, it tends to rub against clothing or the like during application, causing peeling. On the other hand, the upper limit is not particularly limited, but 2.0 N / 24 mm is preferred. If the adhesive strength exceeds 2.0, the bandage may be difficult to peel off after use, or the nonwoven fabric surface layer may peel off.

[0042] The adhesive bandage (A) preferably has an air permeability of 10.0 seconds / 100 mL or less. If the air permeability exceeds 10.0 seconds / 100 mL, the bandage tends to become stuffy when applied in the summer, etc.

[0043] The adhesive bandage (A) of the present invention, which satisfies all of the above numerical ranges for each characteristic, can be obtained mainly by controlling the type, size, shape, etc. of the embossed pattern (embossed pattern) on the support layer (a1), the heat and compression force (pressure) during embossing, etc., and further by controlling the adhesive strength of the adhesive layer (a2).

[0044] The adhesive bandage (A) of the present invention, which satisfies the above-mentioned numerical ranges for each property, has excellent flexibility and elasticity derived from the ultrafine urethane nonwoven fabric in the support layer (a1), as well as the following features: 1. Even when wrapped around a finger or the like and applied manually with one end attached to the back surface, the end does not easily peel off. In addition, the interlayer strength of the support is strong, so that when the end is peeled from the back surface, the support is unlikely to peel off and the adhesive layer remains on the skin. 2. Even after doing water work or taking a bath, the patch drains water well (feels dry) immediately afterwards and does not become too swollen at the application site. 3. On the other hand, embossing tends to reduce the breathability of the support, but when used as a bandage, this can be kept within a range that does not cause any particular problems in practical use, and the various properties required for a bandage are well balanced.

[0045] 6. Manufacturing method of adhesive bandage (A) The method for producing the adhesive bandage (A) of the present invention is not particularly limited. For example, one side of a support layer (a1) made of a nonwoven fabric formed from ultrafine urethane fibers may be embossed, followed by directly applying an organic solvent solution or emulsion of the adhesive component to the side opposite the embossed surface, and then foaming the adhesive to form a foamed adhesive layer (a2). Alternatively, an organic solvent solution or emulsion of the adhesive may be applied to a casting paper coated with a silicone-based release agent or the like, and the adhesive may be foamed to form a foamed adhesive layer (a2), which may then be laminated with a support layer (a1) made of a nonwoven fabric formed from ultrafine urethane fibers. If the adhesive layer (a2) does not cover the entire surface of the support layer (a1), the adhesive synthetic resin solution or emulsion may be applied in a dotted, striped, or other pattern, as desired. The final product form of the adhesive bandage (A) is a laminate in which the support layer (a1), adhesive layer (a2), and release sheet (c) are laminated in this order, cut to a certain width (any width within the range of approximately 5 mm to 100 mm) in the width direction during coating, and wound into a roll of an appropriate length, or into slices cut to an appropriate length (any width within the range of approximately a few cm to 1 m).

[0046] When the adhesive bandage of the present invention is a first aid bandage (B), the manufacturing method is as follows: cut the pad layer (b) into an appropriate size, and place the adhesive bandage (A) in a piece of any length within the range of several centimeters to 10 cm approximately in the center of the adhesive surface, and usually further place a release paper (c), and cut it into the shape of the first aid bandage (usually a rectangle with four circular corners), with the long side direction aligned with the width direction at the time of coating, to obtain the adhesive bandage.Usually, in a later process, the first aid bandage is enclosed in a wrapping paper made of paper, plastic film, or a composite material thereof, to become a product.

[0047] <Polyurethane nonwoven fabric for adhesive bandages> The present invention also includes a polyurethane nonwoven fabric suitable for use as a support layer in the adhesive bandage of the present invention. Note that the polyurethane nonwoven fabric for adhesive bandages of the present invention is described as an "ultrafine urethane nonwoven fabric" in the adhesive bandage section, and the description of the "ultrafine urethane nonwoven fabric" in the adhesive bandage section can be applied to the details.

[0048] A preferred embodiment of the polyurethane nonwoven fabric for adhesive bandages of the present invention is a polyurethane nonwoven fabric that is embossed on at least one surface, has a water retention ratio per weight of 0.8 or less, an air resistance of 1.6 kPa·s / m or less, and a ratio (Y / X) of 30% tensile load (X) in the machine direction (MD) to 30% tensile load (Y) in the cross direction (CD) of 1.0 to 2.0. It is preferable that X is 2.5 to 4.0 N / 24 mm, and Y is 2.5 to 4.5 N / 24 mm. The basis weight is 50 to 100 g / m. 2 When such a polyurethane nonwoven fabric (ultrafine polyurethane nonwoven fabric) is used in the support layer of a bandage, it is possible to obtain a bandage that has good strength, stretchability, and appearance, feels less uncomfortable when applied, and highly satisfies other required qualities such as breathability. [Example]

[0049] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0050] <Making adhesive bandages> Polyhexamethylene diol having a number average molecular weight of 2,000, 4,4-diphenylmethane diisocyanate, and 1,4-butanediol were melt-polymerized in a twin-screw polymerizer to obtain a polyether polyurethane elastomer having a Shore A hardness of 90. This polyurethane elastomer was melt-blow spun, and the resulting molten fibers were dropped onto a net conveyor and spun to a basis weight of 65 g / m. 2 (raw material 1) and 90 g / m 2A melt-blown nonwoven fabric (ultrafine urethane fiber nonwoven fabric) (raw roll 2) was obtained. The average fiber diameter of the polyurethane fibers forming this melt-blown nonwoven fabric was 10.6 μm. The obtained ultrafine urethane fiber nonwoven fabric was subjected to heat embossing by a point heat pressing method to form the support layer (a1) of the adhesive bandage.

[0051] The embossing conditions were as follows: the embossed pattern was a diagonal grid pattern with numerous recesses defined by intersecting ridges (protruding stripes), with the ridge width being 70 μm, the ridge spacing (recess width) being 0.99 mm, and the recess depth being 470 μm. The total area of ​​the protrusions (ridges, etc.) raised on the back surface of the nonwoven fabric support was 7% of the total area of ​​the nonwoven fabric, and the total area of ​​the recesses was 25%. The thermocompression bonding spots were spaced at a pitch of 1.98 mm in both the MD (machine direction) and CD (cross direction).

[0052] During the heat embossing process, the pressure was kept constant at 45 kN (linear pressure 30 N / mm) for both raw rolls 1 and 2, and the temperature was varied in four stages, named 1-1, 1-2, 1-3, and 1-4 (all for raw roll 1) and 2-1, 2-2, 2-3, and 2-4 (all for raw roll 2) from the lowest temperature. The processing temperature and embossing depth correlated, with the higher the processing temperature, the deeper the embossing depth. The embossing depth was judged to be good when the airflow resistance was 0.5 to 1.1 for raw roll 1 and 0.75 to 1.3 for raw roll 2.

[0053] On the other hand, an acrylic adhesive solution [100 parts by weight of 2-ethylhexyl acrylate / vinyl acetate / acrylic acid (87 / 10 / 3) with 0.03 parts by weight of an epoxy crosslinker (Tetrad X; manufactured by Mitsubishi Gas Chemical Co., Inc.)] was applied to silicone-treated casting paper so that the thickness after drying was 40 μm. As a breathability treatment, distilled water was sprayed onto the wet coated surface, and then heated to 130 ° C to form fine holes, forming an adhesive layer (a2) made of a breathable acrylic resin. This was then attached to the above-mentioned ultrafine urethane fiber nonwoven fabric to produce an adhesive bandage (A).

[0054] A gauze pad layer (b) was pre-cut to a width of 13 mm and a length of 22 mm. It was placed on the surface of the original bandage (A), facing the breathable acrylic adhesive layer (a2) exposed by peeling the release paper from the bandage (A), with a gap of 12 mm in the MD and 50 mm in the CD. The bandage (A) and pad layer (b) were then covered with a release paper (c) made of glassine paper treated with a silicone resin. The bandage (A) and pad layer (b) were then punched out into a roughly rectangular shape with rounded corners, 25 mm wide and 72 mm long, aligned with the long side of the original bandage width, with the pad layer (b) positioned approximately in the center, to obtain the first-aid bandage (B). The ratio of the area of ​​the pad layer (b) to the area of ​​the bandage (A) was approximately 16%. The results of the measurements of various properties of this first-aid bandage and the results of its practical evaluation are shown in Table 1 and Figures 1-4. Furthermore, when comparing the 30% tensile load values ​​for the nonwoven fabric and adhesive bandage, the adhesive bandage tends to be slightly higher in the MD and the nonwoven fabric in the CD. This is the result of tension being applied in the MD during adhesive processing, causing a change in the orientation of the ultra-fine urethane filaments.

[0055] <Characteristics evaluation> The properties of the nonwoven fabric and adhesive bandage were evaluated by the following methods.

[0056] (1) Test atmosphere Measurements were performed at a temperature of 23±2°C and a relative humidity of 50±5%. The samples were conditioned in the same atmosphere for 24 hours, and the test pieces were attached to the adherends and then subjected to the test 30 minutes later.

[0057] (2) Weight According to JIS-L1913 "General nonwoven fabric test method", the weight of a 250mm x 250mm test piece was measured and 2 Converted to per.

[0058] (3) Airflow resistance Using a Kato Tech Co., Ltd. air permeability tester (KES-F8-AP1), two samples were stacked and fixed to the device, and the air resistance was measured for a total of 6 seconds, consisting of 3 seconds of exhaust and 3 seconds of intake.

[0059] (4) Water retention capacity The nonwoven fabric was cut to a fixed size (100mm x 100mm) and weighed, then soaked in water for 30 minutes, then picked up with tweezers, removed, and shaken two or three times to remove water (until there were no drips).Then, it was immediately weighed, and the water retention ratio per weight was calculated using the following formula. (Weight after draining - Weight before immersion) / Weight before immersion

[0060] (5) 30% tensile load In accordance with JIS-K7115, both ends of a cut piece of nonwoven fabric raw material, 24 mm wide and 150 mm long with the MD or CD as the long side, were gripped straight at a distance of 100 mm in a tensile tester and pulled at a pulling speed of 300 mm / min, and the stress was read when pulled 30 mm.

[0061] (6) Thickness of adhesive bandage The sample was measured at five points using a dial gauge (1 / 100, probe diameter: 5 mmφ), and the average value was calculated.

[0062] (7) Basis weight of adhesive bandage The sample was cut into a square measuring 100 mm in length and width and weighed to determine the basis weight.

[0063] (8) Adhesion to Bakelite board The adhesive strength of the adhesive bandage was measured using a test piece (A) cut to a width of 24 mm and a length of 250 mm. The adhesive side of the test piece was pressed onto a Bakelite test panel whose surface had been previously cleaned, and then the test piece was attached using a 2 kg roller at a compression speed of 300 mm / min with one back-and-forth motion. After 20 minutes of application, the adhesive strength to the Bakelite plate was measured according to JIS-Z0237 at a peel angle of 180° and a peel speed of 300 mm / min.

[0064] (9) Adhesion strength of adhesive to the embossed surface of the support (self-backside adhesive strength) A piece of adhesive bandage measuring 24 mm wide (original roll MD) and 100 mm long (original roll CD) was attached to a Bakelite board, and the adhesive side of a piece measuring 24 mm wide and 240 mm long was attached to the back of the piece so that both ends were aligned and overlapping.A load of 50 g was applied once, and then the peel force from the back of the piece in the 180-degree direction was measured using a tensile tester at a pulling speed of 300 mm / min.

[0065] (10) Breathability of adhesive bandage (A) The air permeability of the adhesive bandage (A) was measured using a Gurley densometer (Tester Sangyo Co., Ltd.) in accordance with JIS-P8117. Specifically, the adhesive bandage (A) was cut into a size of 50 mm x 50 mm, and if a release sheet was provided, the release sheet was peeled off and the bandage was attached to a clamping plate (base). The area through the clamping plate was 645.16 mm 2 The inner cylinder of the Gurley densometer was pulled out and set on a stopper, after which the test specimen was clamped between clamping plates, and the inner cylinder was gently lowered to measure the number of seconds it took for 100 mL of air to pass through, which was taken as the air permeability (sec / 100 mL).

[0066] <Practical evaluation> A total of 10 healthy volunteers, five men and five women, wrapped the first aid bandage sample (B) around the first joint of the index finger with the pad layer facing the back of the hand and the adhesive side of one end overlapping the surface of the first aid bandage.After 24 hours, including bathing at night on the day of application, the bandage was removed and the volunteers self-evaluated the following various conditions on a scale of 4 to 6, and the average values ​​were calculated.

[0067] (1) Discomfort (immediately after application, during application) 5: No discomfort 4: There is some discomfort 3: There is some discomfort, but no problem 2: There is something strange and there is a problem 1: There is a strong sense of incongruity 0: Peeled off due to excessive discomfort

[0068] (2) Itching during application 5: No itching 4: Slight itching 3: Itchy but no problem 2: Itchy and problematic 1: Itchy and very problematic 0: Peeled off due to excessive itching

[0069] (3) How easily the bandage dries after bathing 5: I don't mind 4: A little slow, but not a problem 3: I can't say 2: It's a little slow and annoying 1: It's slow and bothersome

[0070] (4) Adhesion to the skin just before peeling, and adhesion of the overlapping part of the bandage just before peeling 5: Well-adhered all over 4: The edges are slightly peeled off 3: Peeled off about 1 / 3 2: About half peeled off 1: The pad has peeled off to the point that it is peeling off. 0: Peeled off and fell off

[0071] (5) Peeling condition of overlapping parts of adhesive bandages when peeled off (evaluation of interlayer strength) 5: No delamination occurred and the adhesive was peeled off cleanly from the surface of the adhesive bandage. 4: Some of the adhesive tape surface layers were peeled off. 3: Delamination of the surface layer of the adhesive bandage occurred over more than half of the area. 2: Delamination of the surface layer of the adhesive bandage occurred over the entire surface.

[0072] (6) Softening of the skin immediately after peeling 5: No soggy 4: Slightly swollen 3: It's swollen, but that's okay 2: Soggy and stinging 1: Excessive maceration causes peeling of the skin

[0073] [Table 1]

[0074] From the results shown in Table 1 and Figures 1 to 4 (the numbers on the horizontal axis of the figures represent the end number of the original roll, the numbers on the vertical axis represent the numerical values ​​of each evaluation item, and the graphs are lines connecting the average evaluation results for each original roll), the following can be deduced. That is, whether the basis weight is 65 or 90, as the embossing on the nonwoven fabric surface becomes deeper, in practical evaluation, (i) the ease with which the bandage dries after bathing tends to improve, and this tendency was found to correlate with the water retention capacity per weight. On the other hand, (ii) the adhesion of the overlapping portion of the bandage just before peeling tends to decrease, and this tendency was found to correlate with the self-back adhesive strength.

[0075] When the results of each experimental example were examined, in Examples 1 to 4, which used raw rolls 1-2, 1-3, 2-2, and 2-3 as the support, the ease with which the bandages dried after bathing was excellent, with an average score of 4.0 or higher for 10 people in a practical test, and the adhesion of the overlapping part of the bandage just before peeling off was excellent, with a result of 1.7 or higher in the same practical test.Other than that, the discomfort immediately after application, discomfort during application, itching during application, adhesion to the skin just before peeling off, the peeling state of the overlapping part of the bandage when peeled off, and softening of the skin immediately after peeling were all within acceptable ranges, making these bandages highly balanced for practical use.

[0076] On the other hand, in Comparative Examples 1 to 4, which use the original rolls 1-1, 1-4, 2-1, and 2-4 as the support, all of the following are acceptable: discomfort immediately after application, discomfort during application, itching during application, adhesion to the skin immediately before peeling, peeling state of the overlapping part of the adhesive bandage when peeled, and softening of the skin immediately after peeling.However, in Comparative Examples 1 and 3, the degree (depth) of the embossing is relatively shallow, and although the adhesion of the overlapping part of the adhesive bandage immediately before peeling is excellent, the adhesive bandage after bathing is slightly inferior.In addition, in Comparative Examples 2 and 4, the degree (depth) of the embossing is relatively deep, and although the adhesive bandage after bathing is excellent, the adhesive bandage of the overlapping part immediately before peeling is slightly inferior, and all of them are inferior in the balance of practical properties compared to the adhesive bandage of the present invention. [Industrial Applicability]

[0077] According to the present invention, by embossing an ultra-fine polyurethane nonwoven fabric formed under specific conditions under specific conditions, an excellent adhesive bandage can be obtained in which, when wrapped around a finger or the like, the nonwoven fabric is neither too tight nor too loose, but just tight enough, and is less likely to loosen and slip off even when repeatedly stretched and contracted, and peeling from the edges is suppressed when applied.In addition, the adhesive strength, water retention capacity (dryness), breathability, interlayer strength, etc. of the nonwoven fabric are within practically suitable ranges.

Claims

1. A long, thin adhesive bandage made of an ultra-fine urethane nonwoven fabric with an embossed surface on one side and an adhesive layer on the opposite side of the embossed surface. The ratio (y / x) of the 30% tensile load (x) in the short side direction of the adhesive bandage to the 30% tensile load (y) in the long side direction of the adhesive bandage is 0.8 to 2.0, The water retention ratio per weight of the ultrafine urethane nonwoven fabric is 0.8 or less, The ultrafine urethane nonwoven fabric has an air resistance value of 0.1 to 1.6 kPa·s / m, The adhesive strength of the adhesive bandage to a Bakelite plate is 5.0 to 8.0 N / 24 mm; The adhesive strength (self-back adhesive strength) to the embossed surface of the adhesive bandage is 1.2 N / 24 mm or more, The adhesive bandage has an air permeability of 10.0 sec / 100 mL or less, The adhesive bandage is characterized in that the value obtained by dividing the airflow resistance value by the basis weight (airflow resistance value / basis weight) is within the range of 0.0040 to 0.0160 when the basis weight is 40 g / m 2 or more and less than 60 g / m 2 , and is within the range of 0.0075 to 0.0170 when the basis weight is 60 g / m 2 or more and 100 g / m 2 or less.

2. The adhesive bandage of claim 1, characterized in that the 30% tensile load (x) in the short side direction of the adhesive bandage is 2.0 to 4.0 N / 24 mm, and the 30% tensile load (y) in the long side direction is 2.0 to 4.5 N / 24 mm.

3. In polyurethane nonwoven fabrics, At least one of the surfaces is embossed, The water retention ratio per weight is 0.8 or less, The air resistance value is 0.1 to 1.6 kPa s / m, the ratio (Y / X) of the 30% tensile load (X) in the machine direction (MD) to the 30% tensile load (Y) in the cross direction (CD) is 1.0 to 2.0; The value obtained by dividing the airflow resistance value by the basis weight (airflow resistance value / basis weight) is within the range of 0.0040 to 0.0160 when the basis weight is 40 g / m 2 or more and less than 60 g / m 2 , and is within the range of 0.0075 to 0.0170 when the basis weight is 60 g / m 2 or more and 100 g / m 2 or less.

4. The X is 2.5 to 4.0 N / 24 mm, The polyurethane nonwoven fabric for adhesive bandages according to claim 3, wherein the Y is 2.5 to 4.5 N / 24 mm.

5. Weight per unit area: 50 to 100 g / m ２ 5. The polyurethane nonwoven fabric for adhesive bandages according to claim 3 or 4, which is

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