Sound-absorbing sheets and stoma appliances

Abstract

To provide a sound absorption sheet which has the re-peelability having both of the excellent adhesiveness and the excellent peelability to an adherend and the excellent sound absorption property, and provide a stoma appliance having the sound absorption sheet.SOLUTION: A sound absorption sheet according to the present disclosure includes a lamination constitution in which an adhesive layer and a foam adsorption sound absorption layer are sequentially laminated on a base material. The foam adsorption sound absorption layer is formed of a foamed body of a (meth)acrylic acid ester polymer. The thickness of the foam adsorption sound absorption layer is between 150 μm and 5000 μm inclusive. In a stoma appliance according to the present disclosure, the sound absorption sheet according to the present disclosure is detachably attached onto the surface of a pouch of the stoma appliance on the side of the foam adsorption sound absorption layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a sound-absorbing sheet and a stoma appliance. [Background technology]

[0002] Conventionally, sheets made of fibrous materials such as glass wool or foamed materials such as urethane foam have been widely used as sound-absorbing sheets. Conventionally, such sound-absorbing sheets have been used by being fixed to an adherend with an adhesive or pressure-sensitive adhesive. However, depending on the application of the sound-absorbing sheet, there are cases where it is desired that the sound-absorbing sheet have both adhesiveness and releasability. In other words, there are cases where a sound-absorbing sheet is required to have both the ability to adhere to an adherend with sufficient adhesive strength while it is required to be attached to the adherend (adhesiveness), and the ability to be peeled cleanly from the adherend without leaving any adhesive on the adherend when peeled off from the adherend (releasability).

[0003] For example, in an appliance (stoma appliance) that stores waste discharged from an artificial anus (stoma), it is required to have a sound absorbing mechanism to reduce the sound emitted from the stoma. In a person wearing a stoma appliance, gas is generated in the intestinal tract, and this gas may be discharged from the stoma and emit a sound (discharge sound). The generation of such discharge sound is very often a hindrance to the wearer in social situations such as meetings, customer service, and concerts, and there is a strong demand for reducing the discharge sound. Therefore, there is a demand for a stoma appliance with a sound absorbing mechanism.

[0004] As an example of a stoma appliance having a sound absorbing mechanism, a stoma appliance has been proposed in which a sound absorbing nonwoven material or a sound absorbing multilayer film is bonded to the outer surface of the pouch of the stoma appliance to form an integrated structure (Patent Document 1). The sound absorbing nonwoven material contains fibers containing a triblock copolymer containing a polystyrene block and a vinyl bond-rich rubber midblock. The sound absorbing multilayer film contains at least one layer containing a triblock copolymer containing a polystyrene block and a vinyl bond-rich rubber midblock.

[0005] As another example, a sound reduction device in which a proximal thin film and a distal thin film are affixed to a pouch of a stoma appliance has been proposed (Patent Document 2). The thin film is made of a material selected from the group consisting of silicone, polyethylene, polyethylene terephthalate, polypropylene, and PVC. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2015-503405 [Patent Document 2] Patent No. 6557265 Summary of the Invention [Problem to be solved by the invention]

[0007] It is preferable that the sound absorbing mechanism for reducing the sound emitted from the stoma is easily detachable from the stoma appliance. If the sound absorbing mechanism is easily detachable, the wearer of the stoma appliance can remove the sound absorbing mechanism from the stoma appliance when, for example, taking a bath, and then attach the sound absorbing mechanism to the stoma appliance again after bathing. This attachment and detachment can prevent hot and cold water from entering the sound absorbing mechanism during bathing. Furthermore, if the sound absorbing mechanism is a sheet made of a fiber material or a foam material, it can be made lighter, so that even if the stoma appliance has a sound absorbing mechanism, it does not place a particular burden on the wearer of the stoma appliance.

[0008] However, in a stoma appliance configured as in Patent Document 1, the sound-absorbing material cannot be removed from the stoma appliance, so if the stoma appliance gets wet during bathing, etc., it becomes difficult to remove moisture from the sound-absorbing material, making the wearer uncomfortable. When the sound-absorbing material absorbs moisture, its sound-absorbing performance decreases.

[0009] In addition, even in the stoma appliance having the configuration as in the above-mentioned Patent Document 2, the proximal thin film and the distal thin film serving as the sound reduction device cannot be removed from the stoma appliance. In addition, the proximal thin film and the distal thin film fixed as the sound reduction device have elasticity but insufficient sound absorption performance.

[0010] On the other hand, when using a conventional sound-absorbing sheet as a sound-absorbing mechanism in a stoma appliance, there are methods such as attaching the sound-absorbing sheet to the stoma appliance with a fixing belt, or pressing the sound-absorbing sheet onto the stoma appliance from above (outside the human body) with a belly band-like cloth, but these methods have problems such as being bulky when in use and the need to prepare accessories for these separately. Also, sound-absorbing sheets made of a single material such as urethane foam do not have sufficient sound absorption properties.

[0011] The present disclosure has been made in consideration of these points, and has as its main object to provide a sound-absorbing sheet that has excellent sound-absorbing properties, i.e., good adhesion to an adherend and good releasability, and also has excellent removability, and a stoma appliance that has this sound-absorbing sheet. [Means for solving the problem]

[0012] The sound-absorbing sheet of the present disclosure has a laminated structure in which an adhesive layer and a foamed adsorption sound-absorbing layer are laminated in that order on a substrate, the foamed adsorption sound-absorbing layer being made of a foam of a (meth)acrylic ester polymer, and the thickness of the foamed adsorption sound-absorbing layer is 150 μm or more and 5000 μm or less.

[0013] In the sound-absorbing sheet of the present disclosure, the foamed sound-absorbing layer has a basis weight of 60 g / m 2 More than 600g / m2 It may be the following.

[0014] In the sound absorbing sheet of the present disclosure, the foamed, adsorbent sound absorbing layer may have an expansion ratio of 2.0 or more and 4.0 or less.

[0015] In the sound absorbing sheet of the present disclosure, the adhesive layer may be made of a (meth)acrylic acid ester copolymer.

[0016] In the sound-absorbing sheet of the present disclosure, the base material may include a polyurethane foam.

[0017] In the sound-absorbing sheet of the present disclosure, the substrate may have a layered structure in which a first substrate layer and a second substrate layer are laminated, the first substrate layer has an opening and a notch in a part of the outer periphery of the first substrate layer, the notch being connected to the opening, and the foamed adsorption sound-absorbing layer may be provided on a side of the first substrate layer opposite to the side on which the second substrate layer is located.

[0018] In the sound absorbing sheet of the present disclosure, the first base material layer may have a greater thickness than the second base material layer.

[0019] The stoma appliance of the present disclosure comprises a base plate that is adhered to the skin around the stoma and has a stoma hole through which the stoma is inserted, a pouch that is connected to the base plate and contains waste from the stoma, and the sound-absorbing sheet that is attached onto the surface of the pouch, and the sound-absorbing sheet is removably attached onto the surface of the pouch on the side of the foam adsorbent sound-absorbing layer.

[0020] In the stoma appliance of the present disclosure, the sound-absorbing sheet may be attached in a position covering the stoma hole when viewed from a direction perpendicular to the base plate. Effect of the Invention

[0021] According to the present disclosure, it is possible to provide a sound-absorbing sheet that has excellent sound absorbing properties, and that combines good adhesion to an adherend and good releasability. Furthermore, in the stoma appliance of the present disclosure, the sound-absorbing sheet of the present disclosure can be easily attached and detached, and when the sound-absorbing sheet of the present disclosure is worn, the noise emitted from the stoma can be effectively reduced. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a sound-absorbing sheet according to the present disclosure. [Diagram 2] FIG. 3 is a cross-sectional view showing another example of the sound-absorbing sheet of the present disclosure. [Diagram 3] A process diagram showing an example of a method for producing a sound-absorbing sheet according to the present disclosure. [Figure 4] A process diagram showing another example of the method for producing a sound-absorbing sheet according to the present disclosure. [Diagram 5] FIG. 5 is a diagram for explaining the first laminate shown in FIG. 4. [Figure 6] FIG. 1 shows an example of a stoma appliance according to the present disclosure. [Figure 7] FIG. 7 is a diagram showing an example of a cross-sectional configuration of the stoma appliance shown in FIG. [Figure 8] FIG. 1 is a diagram showing an example of a sound-absorbing sheet according to a stoma appliance of the present disclosure. [Figure 9] FIG. 1 shows an example of a conventional stoma appliance. [Figure 10] FIG. 10 is a diagram showing an example of a cross-sectional configuration of the stoma appliance shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. The embodiments shown below are examples of the embodiments of the present disclosure, and the present disclosure is not limited to these embodiments. In this specification, terms such as "substrate", "sheet", and "film" are not distinguished from each other based only on the difference in designation. For example, "substrate" is a concept that includes members that can be called sheets and films. Furthermore, terms such as "vertical" and values ​​of length and angle that specify the shape and geometric conditions and their degree used in this specification are interpreted to include the range in which similar functions can be expected without being bound by strict meaning. In addition, in the drawings referred to in this embodiment, the same or similar symbols are given to the same parts or parts having similar functions, and repeated explanations thereof may be omitted. In addition, the dimensional ratios of the drawings may differ from the actual ratios for the convenience of explanation, or part of the configuration may be omitted from the drawings.

[0024] <Sound absorbing sheet> Fig. 1 is a cross-sectional view showing an example of the sound-absorbing sheet of the present disclosure, and Fig. 2 is a cross-sectional view showing another example of the sound-absorbing sheet of the present disclosure.

[0025] 1, the sound-absorbing sheet 1 has a laminated structure in which an adhesive layer 12 and a foamed adsorption sound-absorbing layer 13 are laminated in this order on a substrate 11. The sound-absorbing sheet of the present disclosure may also have a laminated structure in which an adhesive layer 12, a foamed adsorption sound-absorbing layer 13, and a release material 21 are laminated in this order on a substrate 11, as in the sound-absorbing sheet 2 shown in FIG.

[0026] Here, the sound absorbing sheet 2 shown in Fig. 2 has a configuration in which a release material 21 is provided on the foamed adsorbent sound absorbing layer 13 of the sound absorbing sheet 1 shown in Fig. 1, and by peeling off the release material 21 when attaching the sound absorbing sheet to an adherend, the sound absorbing sheet 2 becomes as shown in Fig. 1. In other words, the sound absorbing sheet 2 shown in Fig. 2 can be said to be in the state before use of the sound absorbing sheet 1 shown in Fig. 1. Hereinafter, each of the components constituting the sound-absorbing sheet of the present disclosure will be described.

[0027] (base material) The substrate 11 holds the adhesive layer 12 and the foamed adsorption sound absorbing layer 13. In the sound absorbing sheet 1, the substrate 11 and the foamed adsorption sound absorbing layer 13 are firmly bonded by the adhesive layer 12, so that even if the sound absorbing sheet 1 is repeatedly attached to and peeled off from an adherend, the substrate 11 and the foamed adsorption sound absorbing layer 13 do not become separated from each other. Here, the substrate 11 preferably has flexibility so that it can follow the surface shape of the adherend when attached or peeled off.

[0028] In the sound absorbing sheet of the present disclosure, as will be described later in the manufacturing method of a foamed adsorbent sound absorbing layer, the foamed adsorbent sound absorbing layer 13 that has been subjected to a heat drying process is bonded to the substrate 11 via the adhesive layer 12. Examples of the substrate 11 include nonwoven fabrics having sound absorbing and vibration damping properties, and polymeric porous bodies such as urethane and polyester.

[0029] The total thickness of the substrate 11 is preferably 5 mm or more and 100 mm or less, more preferably 5 mm or more and 30 mm or less. If the total thickness of the substrate 11 is within the above range, it becomes a thin sound absorbing sheet, and can be used for various purposes where a thin sound absorbing sheet is required. In addition, the average density of the sound absorbing sheet is preferably 300 kg / m 3 More preferably, it is 1 kg / m or less. 3 More than 200kg / m 3 More preferably, it is 5 kg / m or less. 3 More than 150kg / m 3 or less, and particularly preferably 10 kg / m 3 More than 100kg / m 3 or less, most preferably 20 kg / m 3 More than 50kg / m 3 The following is the result.

[0030] [Nonwoven fabric] The nonwoven fabric having sound absorbing and vibration damping properties may be either a nonwoven fabric made of short fibers or a nonwoven fabric made of long fibers. For example, needle punched nonwoven fabric, water jet punched nonwoven fabric, melt blown nonwoven fabric, spun bonded nonwoven fabric, stitch bonded nonwoven fabric, etc. are used. Among them, needle punched nonwoven fabric or water jet punched nonwoven fabric is preferred, and needle punched nonwoven fabric is particularly preferred. Miscellaneous felt can also be used as the nonwoven fabric. Its basis weight is 150 g / m 2 More than 800g / m 2 The bulk density is preferably in the range of 0.01 g / cm 3 More than 0.2g / cm 3 It is preferable that:

[0031] The cross-sectional shape of the fibers constituting the nonwoven fabric is not particularly limited, and may be a perfect circle or an irregular cross-sectional shape, such as an ellipse, hollow, X-shaped, Y-shaped, T-shaped, L-shaped, star-shaped, lobed (e.g., trefoil, tetralobal, pentacole, etc.), or other polygonal (e.g., triangular, rectangular, pentagonal, hexagonal, etc.) cross-sectional shape.

[0032] The fibers constituting the nonwoven fabric may be natural or synthetic, but synthetic fibers are preferably used from the viewpoint of durability. Examples of such fibers include thermoplastic fibers such as polyester fibers, polyamide fibers (e.g., nylon fibers, etc.), acrylic fibers, and polyolefin fibers (e.g., polypropylene fibers, polyethylene fibers, etc.), and the above-mentioned fiber materials can be used by known methods such as wet spinning, dry spinning, or melt spinning. Among them, polyester fibers, polypropylene fibers, and nylon fibers are preferred from the viewpoint of excellent durability and abrasion resistance. In particular, polyester fibers are most preferred from the viewpoints that the raw polyester can be easily recycled by thermal melting of used nonwoven fabric, it is economical, the texture of the nonwoven fabric is good, and it is excellent in moldability.

[0033] [Porous polymers] Specific examples of the polymeric porous body include polyurethane foam, polystyrene foam, polyolefin (e.g., polyethylene, polypropylene) foam, and ethylene-propylene-diene rubber (EPDM) foam. Any appropriate structure can be adopted as the porous structure of the polymeric porous body depending on the purpose. For example, such a structure may be a closed cell structure in which each cell formed by foaming is independent, or a continuous cell structure in which at least a part of the cells are continuous.

[0034] The polyurethane foam is composed of a porous elastic body made of polyurethane having a plurality of pores. The polyurethane forming the matrix of the porous elastic body can be produced by polymerization reaction of a polyol component and a polyisocyanate component.

[0035] The polyol component includes a high molecular weight polyol and a chain extender. Examples of the high molecular weight polyol include polyether polyols such as polypropylene glycol, polytetramethylene glycol, and polymer polyols, adipate polyols, polyester polyols such as polycaprolactone polyols, polycarbonate polyols, and polyolefin polyols. Examples of the chain extender include low molecular weight diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 3-methyl-1,5-pentanediol.

[0036] The polyisocyanate component includes a polyisocyanate compound. Examples of polyisocyanates contained in the polyisocyanate component include aromatic isocyanates such as tolylene diisocyanate (TDI), diphenylmethane-4,4'-diisocyanate (MDI), xylylene diisocyanate (XDI), 1,5-naphthalene diisocyanate (NDI), and tetramethylxylylene diisocyanate (TMXDI), alicyclic isocyanates such as isophorone diisocyanate (IPDI) and hydrogenated xylylene diisocyanate (H6XDI), and aliphatic isocyanates such as hexamethylene diisocyanate (HDI), dimer acid diisocyanate (10-[5,6-dihexyl-2-(8-isocyanatooctyl)-3-cyclohexen-1-yl]-9-decenyl isocyanate), and norbornene diisocyanate (NBDI).

[0037] The polyol component may be used alone or in combination of two or more of the above. Similarly, the polyisocyanate component may be used alone or in combination of two or more of the above. As a precursor of polyurethane, a polyurethane water dispersion in which polyurethane formed from the polyol component and the polyisocyanate component is dispersed in a water-based solvent may be used.

[0038] The porous elastic body can be formed, for example, as follows: Although not particularly limited, as an example, a method of forming the porous elastic body in an aqueous solvent using a pore-forming component and other additives (such as a surfactant) in addition to the polyol component and the polyisocyanate component by a water coagulation method will be described.

[0039] First, in addition to the polyol component and the polyisocyanate component, a pore-forming component, a water-based solvent, and other additives are prepared.

[0040] As the pore-forming component, a pore-forming agent made of a water-soluble inorganic salt can be used. Examples of such inorganic salts include sodium salts and potassium salts. More specifically, chlorides such as sodium chloride and potassium chloride, and sulfates such as sodium sulfate (mirabilite) and potassium sulfate (sulfate) can be used.

[0041] When the pore-forming component dissolves in the polyurethane, cavities are formed where the pore-forming component was present. These cavities become the source of the pores in the porous elastic body. As an example, it is preferable that the pore-forming component at least partially contains a pore-forming agent with an average particle size of 50 μm or less. In order to reduce the variation in the size of the pores formed, it is preferable to use a pore-forming component that contains a pore-forming agent with a narrow particle size distribution. The pore size is related to sound absorption properties and preferably contains an average particle size of 100 μm or more. The pore size is a mixture of pores with diameters of 30 μm or more and 2000 μm or less.

[0042] On the other hand, when the pore size becomes smaller, the strength and elasticity of the foam tend to decrease. Therefore, it is preferable that the porous elastic body contains some pores with large diameters. The thickness of the skeletal structure of the foam surrounding the large pores tends to be thicker than the thickness of the skeletal structure surrounding the small pores. Such a thick skeletal structure acts like a pillar supporting the internal structure of the foam. This increases the strength and elasticity of the foam, making it less likely to collapse.

[0043] Therefore, the pore-forming component preferably contains both a first pore-forming agent having an average particle size of 50 μm or less and a second pore-forming agent having an average particle size of more than 50 μm. The ratio of the second pore-forming agent to the total amount of the pore-forming components can be appropriately selected in consideration of the required strength and elastic modulus. The ratio is, for example, 40% by mass or less, 30% by mass or less, 20% by mass or less, or 10% by mass or less, based on 100% by mass of the pore-forming components.

[0044] The amount of the pore-forming component is preferably 100 parts by mass or more and 2000 parts by mass or less, more preferably 500 parts by mass or more and 1500 parts by mass or less, per 100 parts by mass of the solid content of the polyurethane to be formed. If the amount of the pore-forming component is too small, the pore-forming material does not spread throughout the polyurethane, and the distribution of the pores tends to be non-uniform. If the amount of the pore-forming component is too large, the strength of the porous elastic body tends to decrease. When using a pore-forming agent in an amount of 100 parts by mass or more and 2000 parts by mass or less per 100 parts by mass of the solid content of the polyurethane to be formed, it is preferable because the distribution of the pores formed in the porous elastic body and the strength and elasticity of the porous elastic body are moderate.

[0045] The aqueous solvent may be water or a mixture of water and a water-soluble solvent. Examples of the water-soluble solvent include alcohol-based solvents such as methanol, ethanol, and ethylene glycol. From the viewpoints of low environmental impact and cost, it is preferable to use water alone as the aqueous solvent.

[0046] The amount of the aqueous solvent (preferably water) is preferably 10 parts by mass or more and 300 parts by mass or less, more preferably 10 parts by mass or more and 200 parts by mass or less, per 100 parts by mass of the solid content of the polyurethane to be formed. This range is preferable in that the viscosity of the polyurethane-containing solution is appropriate and the obtained polyurethane has appropriate strength and elasticity.

[0047] Examples of the other additives include surfactants such as sorbitan fatty acid esters, polyglycerin fatty acid esters, polyethylene glycol oleates, etc. The surfactant is preferably used in an amount of 5 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the solid content of the polyurethane to be formed.

[0048] Using these raw materials, a polyurethane porous elastic body is formed by a method called the water coagulation method. First, the above components are charged into a kneading device and kneaded. For kneading, a kneader, an auger kneader, a Banbury mixer, a screw extruder, etc. can be used.

[0049] After kneading, the resulting mixture is degassed. After degassing, the mixture is molded into a desired shape. The degassing method is not particularly limited. For example, degassing under reduced pressure may be performed using a vented extruder. The molding method is also not particularly limited. For example, a molding die (T-die) corresponding to the desired shape may be connected to the vented extruder used for degassing under reduced pressure, and molding may be performed.

[0050] After molding, the obtained molded body is put into water or an aqueous solution. This operation replaces the solvent with water and precipitates polyurethane. This operation is called water coagulation. The procedure up to putting the molded body is not particularly limited, but for example, in the molding process, the kneaded material is extruded and filled into a box-shaped material with an open top using a punching metal made of stainless steel 304 or the like, molding is performed, and the obtained molded body is put into water or an aqueous solution.

[0051] After the water coagulation operation, the pore-forming agent consisting of a water-soluble inorganic salt is removed by dissolving it in water. The method is not particularly limited, but the following method can be mentioned, for example. The molded body of the kneaded material in a container is left in warm water to dissolve most of the pore-forming agent. Then, the molded body is put into a general washing machine or the like and washed in water of 20°C to 80°C for 15 minutes to 90 minutes. During washing, it is preferable to replace the washing water as necessary.

[0052] The molded article thus obtained is then dried. In order to prevent deterioration of the polyurethane due to heat, drying is carried out, for example, in a dryer at 110°C or lower. In this way, a foam made of a polyurethane porous elastic body is obtained.

[0053] The pore size and distribution of the porous elastomer can be controlled by adjusting the ratio of the polyol component and polyurethane component that make up the polyurethane, the kneading conditions and kneading time, the type and amount of additives, the amount, particle size, and particle size distribution of the pore-forming agent, etc. In particular, the ease with which pores are formed varies depending on the type of polyurethane component. Therefore, various conditions are appropriately adjusted depending on the properties of the polyurethane component and the required properties. In addition, the state of pore formation can be changed by adjusting the type and amount of surfactant.

[0054] (Adhesive layer) In the sound absorbing sheet 1, the adhesive layer 12 bonds the base material 11 and the foamed adsorption sound absorbing layer 13 at a temperature of 130° C. or higher and 200° C. or lower. The presence of the adhesive layer 12 prevents the base material 11 and the foamed adsorption sound absorbing layer 13 from becoming separated from each other even when the sound absorbing sheet 1 is repeatedly attached to and peeled off from an adherend. Furthermore, as described below, the sound-absorbing sheet of the present disclosure has the adhesive layer 12, which makes it unaffected by the temperature (130°C or higher and 200°C or lower) of the heating and drying process in forming the foamed adsorption sound-absorbing layer 13.

[0055] Existing adhesives such as acrylic, epoxy, and olefin adhesives can be used as the material for forming the adhesive layer 12. In particular, an acrylic adhesive that can be bonded at room temperature regardless of the substrate can be suitably used. This acrylic adhesive contains a (meth)acrylic acid ester copolymer as the main component, to which a rosin ester tackifying resin is added, and further, an isocyanate crosslinking agent is added to crosslink the (meth)acrylic acid ester copolymer. Here, the term "(meth)acrylic acid ester polymer" refers to a polymer obtained using at least one of an acrylic acid ester and a methacrylic acid ester as a monomer.

[0056] [(Meth)acrylic acid ester copolymer] The (meth)acrylic acid ester polymer preferably contains, as monomer units, a (meth)acrylic acid alkyl ester having an alkyl group with carbon number of 2 to 20, and a monomer having a reactive functional group in the molecule (reactive functional group-containing monomer), which allows the polymer to exhibit desirable adhesiveness.

[0057] The (meth)acrylic acid alkyl ester having an alkyl group carbon number of 2 to 20 is preferably one having a glass transition temperature (Tg) of -40°C or lower as a homopolymer (hereinafter, sometimes referred to as a "specific acrylate"). By containing such a specific acrylate as a constituent monomer unit, excellent flex resistance can be maintained.

[0058] As the specific acrylate, for example, n-butyl acrylate (Tg-55°C), n-octyl acrylate (Tg-65°C), isooctyl acrylate (Tg-58°C), 2-ethylhexyl acrylate (Tg-70°C), isononyl acrylate (Tg-58°C), isodecyl acrylate (Tg-60°C), isodecyl methacrylate (Tg-41°C), n-lauryl methacrylate (Tg-65°C), tridecyl acrylate (Tg-55°C), tridecyl methacrylate (-40°C), etc. are preferably used. Among them, from the viewpoint of more effectively reducing the storage modulus, it is more preferable that the specific acrylate has a homopolymer Tg of -45°C or less, and particularly preferably -50°C or less. Specifically, n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferable. These may be used alone or in combination of two or more. The alkyl group in the (meth)acrylic acid alkyl ester having 2 to 20 carbon atoms refers to a linear, branched or cyclic alkyl group.

[0059] The (meth)acrylic acid ester polymer preferably contains 60% by mass or more of the specific acrylate as a monomer unit, more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0060] In addition, the (meth)acrylic acid ester polymer preferably contains the specific acrylate as a monomer unit in an amount of 99.9% by mass or less, more preferably 99% by mass or less, and particularly preferably 98% by mass or less. By containing the specific acrylate in an amount of 99.9% by mass or less, it is possible to introduce a suitable amount of other monomer components (particularly reactive functional group-containing monomers) into the (meth)acrylic acid ester polymer.

[0061] The (meth)acrylic acid ester polymer contains a reactive functional group-containing monomer as a monomer unit, and reacts with a crosslinking agent described later via the reactive functional group derived from the reactive functional group-containing monomer, thereby forming a crosslinked structure (three-dimensional network structure), and obtaining a desired cohesive strength.

[0062] The reactive functional group-containing monomer contained as a monomer unit in the (meth)acrylic acid ester polymer is preferably a monomer having a hydroxyl group in the molecule (hydroxyl group-containing monomer), a monomer having an amino group in the molecule (amino group-containing monomer), etc. Among these, the hydroxyl group-containing monomer is particularly preferred.

[0063] Examples of the hydroxyl group-containing monomer include (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Among them, from the viewpoints of glass transition temperature (Tg), reactivity of the hydroxyl group in the resulting (meth)acrylic acid ester polymer with a crosslinking agent, and copolymerizability with other monomers, at least one of 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, and 4-hydroxybutyl acrylate is preferred. These may be used alone or in combination of two or more.

[0064] The hydroxyl value of the (meth)acrylic acid ester copolymer is not particularly limited, but from the viewpoint of suppressing the occurrence of separation between the adhesive layer 12 and the base material 11 and between the adhesive layer 12 and the foamed adsorption sound absorbing layer 13 when the sound absorbing sheet is repeatedly bent, the lower limit is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more. On the other hand, the upper limit is preferably 100 mgKOH / g or less, more preferably 90 mgKOH / g or less.

[0065] The (meth)acrylic acid ester polymer preferably contains, as a monomer unit, 0.1 mass % or more of a reactive functional group-containing monomer, more preferably 0.5 mass % or more, and particularly preferably 1 mass % or more. The (meth)acrylic acid ester polymer preferably contains, as a monomer unit, 30 mass % or less of a reactive functional group-containing monomer, more preferably 20 mass % or less, and particularly preferably 8 mass % or less.

[0066] The polymerization mode of the (meth)acrylic acid ester polymer may be a random copolymer or a block copolymer.

[0067] The lower limit of the weight average molecular weight of the (meth)acrylic acid ester polymer is preferably at least 200,000, more preferably at least 300,000, and particularly preferably at least 400,000. When the lower limit of the weight average molecular weight of the (meth)acrylic acid ester polymer is above the above range, problems such as seepage of the adhesive during processing of the sound absorbing sheet are suppressed. In this specification, the weight average molecular weight is a value measured by gel permeation chromatography (GPC) and converted into standard polystyrene.

[0068] The upper limit of the weight average molecular weight of the (meth)acrylic acid ester polymer is preferably not more than 1,000,000, more preferably not more than 900,000, and particularly preferably not more than 800,000. When the upper limit of the weight average molecular weight of the (meth)acrylic acid ester polymer is the above-mentioned or less, the adhesion to an adherend and the storage modulus of the obtained sound absorbing sheet tend to fall within suitable ranges.

[0069] [Rosin ester tackifier resin] The rosin ester-based tackifying resin added to the acrylic adhesive that constitutes the adhesive layer 12 is a rosin ester-based tackifying resin which is an ester of a rosin-based tackifying resin such as gum rosin, wood rosin, or tall oil rosin, which has as its main component a resin acid such as abietic acid, palustric acid, neoabietic acid, pimaric acid, isopimaric acid, or dehydroabietic acid, with various alcohols.

[0070] The content of the rosin ester tackifying resin in the acrylic adhesive constituting the adhesive layer 12 is preferably 1 part by weight or more and 40 parts by weight or less, more preferably 1.5 parts by weight or more and 35 parts by weight or less, and even more preferably 2 parts by weight or more and 30 parts by weight or less, relative to 100 parts by weight of the (meth)acrylic acid ester polymer. If the content is 1 part by weight or more, the bending resistance performance of the sound absorbing sheet is improved. On the other hand, if the content is 40 parts by weight or less, clouding of the sound absorbing sheet can be suppressed.

[0071] [Isocyanate-based crosslinking agent] When an isocyanate-based crosslinking agent is added to the acrylic adhesive constituting the adhesive layer 12 and heated, the isocyanate-based crosslinking agent crosslinks the (meth)acrylic acid ester polymer to form a three-dimensional network structure.

[0072] The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, and biuret and isocyanurate forms thereof, as well as adducts which are reaction products with low-molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, from the viewpoint of reactivity with hydroxyl groups, trimethylolpropane-modified aromatic polyisocyanates, in particular trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylylene diisocyanate, are preferred.

[0073] The content of the isocyanate-based crosslinking agent in the acrylic adhesive constituting the adhesive layer 12 is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by weight of the (meth)acrylic acid ester polymer. The content is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less.

[0074] [Other additives] If necessary, various additives commonly used in acrylic adhesives, such as silane coupling agents, ultraviolet absorbers, antistatic agents, tackifiers, antioxidants, light stabilizers, softeners, fillers, and refractive index adjusters, may be added to the acrylic adhesive constituting the adhesive layer 12.

[0075] (Foamed sound absorbing layer) The foamed sound-absorbing layer 13 is made of a foamed (meth)acrylic acid ester polymer. This foamed material can be obtained, for example, by mechanically foaming a (meth)acrylic acid ester polymer emulsion and then drying it by heating. Mechanical foaming refers to dispersing and mixing air bubbles into an emulsion by mechanical treatment such as stirring and mixing the emulsion. The dispersion medium contained in the mechanically foamed (meth)acrylic acid ester polymer emulsion is evaporated and removed by heating and drying.

[0076] The mechanically foamed (meth)acrylic acid ester polymer emulsion contains a (meth)acrylic acid ester polymer resin as a dispersoid, air bubbles, and a dispersion medium for dispersing these. The (meth)acrylic acid ester polymer foam, which is a heat-dried product of the mechanically foamed (meth)acrylic acid ester polymer emulsion, contains the (meth)acrylic acid ester polymer resin and voids present in this resin. The foamed adsorption sound-absorbing layer 13 has these voids, and thus causes an adsorption phenomenon on the surface of the adherend when it is attached to the adherend. This phenomenon also acts to allow the foamed adsorption sound-absorbing layer 13 to stick to the adherend, i.e., to adhere.

[0077] In the manufacture of the foamed sound-absorbing layer 13, the foaming ratio is adjusted to be 2.0 times or more and 4.0 times or less. If the expansion ratio is less than 2.0 times, the adhesive strength of the foamed adsorption sound absorbing layer 13 to the substrate will be weak, and the sound absorbing sheet 1 may not be able to maintain its adhesion to the substrate with sufficient adhesive strength. Furthermore, if the expansion ratio exceeds 4.0 times, the adhesive strength of the foamed adsorption sound absorbing layer 13 to the adherend becomes too strong, and when the sound absorbing sheet 1 is peeled off from the adherend, the foamed adsorption sound absorbing layer 13 may tear off and remain on the adherend (a phenomenon known as "film residue"). If this film residue occurs, the foamed adsorption sound absorbing layer 13 is partially destroyed, that portion is lost, and it becomes impossible to peel it off again.

[0078] The (meth)acrylic acid ester polymer emulsion can be obtained, for example, by emulsion polymerization of one or more (meth)acrylic acid esters and, if necessary, other monomers other than the (meth)acrylic acid esters in a dispersion medium such as water in the presence of a polymerization initiator and, if necessary, an emulsifier or dispersion stabilizer.

[0079] Examples of the (meth)acrylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, phenyl (meth)acrylate, and (meth)acrylate. Examples of the (meth)acrylic acid heteroatom-containing ester include (meth)acrylic acid hydrocarbon esters such as benzyl acrylate and allyl (meth)acrylate, and (meth)acrylic acid heteroatom-containing esters such as glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, glycerol mono(meth)acrylate, ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate.

[0080] Examples of other monomers include unsaturated carboxylic acid compounds such as (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, itaconic acid monoester, maleic acid monoester, maleic anhydride, and itaconic anhydride; aromatic vinyl compounds such as styrene and divinylbenzene; unsaturated nitrile compounds such as acrylonitrile; conjugated diene compounds such as butadiene and isoprene; diallyl phthalate; and allyl glycidyl ether.

[0081] Examples of the dispersion medium for the (meth)acrylic acid ester polymer emulsion include organic solvents such as water, alcohols such as ethanol, ketones such as acetone, esters such as ethyl acetate, ethers such as dipropyl ether, and glycol ethers such as ethylene glycol monomethyl ether. Of these, water is preferred.

[0082] The (meth)acrylic acid ester polymer emulsion may contain, for example, a surfactant, a silicone compound, etc. One type (or two or more types) of (meth)acrylic acid ester polymer emulsion can be used.

[0083] The lower limit of the glass transition temperature (Tg) of the resin constituting the (meth)acrylic acid ester polymer emulsion is preferably −55° C., more preferably −50° C., even more preferably −45° C., and particularly preferably −40° C. The upper limit of the Tg is preferably 30° C., more preferably 20° C., even more preferably 10° C., and particularly preferably 0° C. By setting the Tg of the (meth)acrylic acid ester polymer within the above range, the adhesive properties of the foamed adsorption sound absorbing layer 13 can be further improved.

[0084] The lower limit of the average particle size of the dispersed matter of the (meth)acrylic acid ester polymer emulsion is preferably 50 nm, more preferably 70 nm, and even more preferably 80 nm. The upper limit of the average particle size is preferably 600 nm, more preferably 500 nm, and even more preferably 400 nm. The average particle size is, for example, the volume-based median size measured by laser diffraction particle size distribution measurement.

[0085] The thickness of the foamed adsorption sound absorbing layer 13 is preferably in the range of 150 μm to 5000 μm. By setting the thickness of the foamed adsorption sound absorbing layer 13 in the above range, the sound absorbing properties and productivity of the foamed adsorption sound absorbing layer 13 can be improved. The "thickness" of the foamed sound-absorbing layer 13 means the arithmetic mean value of thicknesses measured at three different points within a 10 cm square of the foamed sound-absorbing layer 13.

[0086] The weight of the foamed sound absorbing layer 13 is in the range of 60 g / m 2 More than 600g / m 2 It is preferable to keep it below 60g / m 2 If cut, it will not contribute to sound absorption and will be 600g / m 2 If it exceeds this limit, production will become unstable and costs will increase. The "weight" of the foamed sound-absorbing layer 13 refers to the weight per unit area of ​​the foamed sound-absorbing layer 13, and is usually calculated based on the weight per unit area of ​​1 m 2 The weight of the hit is expressed in grams.

[0087] <Method of manufacturing foamed sound absorbing layer> Next, a manufacturing method of the foamed adsorption sound absorbing layer 13 will be described. The manufacturing method of the foamed adsorption sound absorbing layer 13 includes a step of mechanically foaming a (meth)acrylic acid ester polymer emulsion (hereinafter also referred to as a "mechanical foaming step"), a step of coating one surface of a release material with the mechanically foamed (meth)acrylic acid ester polymer emulsion obtained by the mechanical foaming step (hereinafter also referred to as a "coating step"), and a step of heating and drying the coating layer formed by the coating step (hereinafter also referred to as a "heat drying step"). Each step will be described below.

[0088] [Mechanical foaming process] In this step, the (meth)acrylic acid ester polymer emulsion is mechanically foamed. Examples of the device used for mechanical foaming include a batch type foaming machine and a continuous type foaming machine. Examples of the gas introduced in the mechanical foaming include air, nitrogen, oxygen, etc.

[0089] During mechanical foaming, for example, the tackifier resin (rosin ester-based tackifier resin) used in the adhesive layer 12, a thickener, a foam stabilizer, etc. may be added to the (meth)acrylic acid ester polymer emulsion.

[0090] The conditions of the batch type foaming machine, such as the stirring rotation speed and foaming time, are appropriately selected so that the density of the mechanically foamed (meth)acrylic acid ester polymer emulsion obtained is a desired value. The stirring rotation speed of the batch type foaming machine can be, for example, in the range of 100 rpm or more and 300 rpm or less. The foaming time of the batch type foaming machine can be, for example, in the range of 1 minute or more and 60 minutes or less.

[0091] The conditions in the continuous foaming machine, such as the liquid flow rate, gas flow rate, mixer rotation speed, etc., are appropriately selected so that the density, flow rate, etc. of the obtained mechanically foamed (meth)acrylic acid ester polymer emulsion become the desired values.

[0092] [Coating process] In this step, the mechanically foamed (meth)acrylic acid ester polymer emulsion obtained in the mechanical foaming step is applied to one surface of a predetermined release material. As described later, in the present disclosure, a release material 21 or the like can be used as a substrate to which the mechanically foamed (meth)acrylic acid ester polymer emulsion is applied. Details will be described later in the method for producing an adsorption sheet.

[0093] Examples of the coating method include a casting head method, a roll coating method, an air knife coating method, a gravure roll coating method, a doctor roll coating method, a doctor knife coating method, a curtain flow coating method, a spray method, and a brush coating method.

[0094] The thickness of the coating layer to be formed is appropriately selected so that the thickness of the foam of the (meth)acrylic acid ester polymer formed by heat drying has a desired value. The thickness of the coating layer to be formed can be, for example, in the range of 80 μm to 8000 μm.

[0095] [Heat drying process] In this step, the coating layer formed in the coating step is dried by heating. That is, the dispersion medium in the mechanically foamed (meth)acrylic acid ester polymer emulsion constituting the coating layer is evaporated by heating. As a result, a (meth)acrylic acid ester polymer foam, which is a heat-dried product of the mechanically foamed (meth)acrylic acid ester polymer emulsion, is formed on the release material. The formed (meth)acrylic acid ester polymer foam contains the (meth)acrylic acid ester polymer resin and voids present in this resin.

[0096] Examples of devices for heating and drying the coating layer include an oven, a hot plate, a hot air dryer, and a hot air circulation oven.

[0097] The conditions of the heat drying, such as temperature and time, are appropriately selected so that the dispersion medium is not substantially contained in the foam of the (meth)acrylic acid ester polymer that is formed. The heat drying is carried out at a temperature of 130° C. or more and 200° C. or less. Of these, a temperature of 140° C. or more and 150° C. or less is preferably used. From the viewpoint of improving productivity, the heat drying time is preferably 60 minutes or less, and more preferably 40 minutes or less.

[0098] (Release material) The sound-absorbing sheet of the present disclosure before being attached to an adherend (i.e., the sound-absorbing sheet before use) preferably has a configuration having a release material 21 on a foamed adsorbent sound-absorbing layer 13, for example, as in the sound-absorbing sheet 2 shown in Figure 2.

[0099] The release material 21 protects the foamed adsorption sound absorbing layer 13 of the sound absorbing sheet before it is put into use, and prevents the foamed adsorption sound absorbing layer 13 of the sound absorbing sheet before it is put into use from sticking to other objects unintentionally.

[0100] Furthermore, as described below, in the production of the sound-absorbing sheet of the present disclosure, when forming the foamed adsorption sound-absorbing layer 13, a release material 21 or the like can be used as a substrate to which the mechanically foamed (meth)acrylic acid ester polymer emulsion is applied.

[0101] Since the heating and drying temperature for forming the foamed adsorbent sound absorbing layer 13 is high, when using the release material 21 as a substrate for coating the mechanically foamed (meth)acrylic acid ester polymer emulsion, it is necessary to select a release material having a melting point of 130° C. or higher. For example, PET (thickness 12 μm or more and 70 μm or less) is preferably used as the release material.

[0102] On the other hand, in the sound-absorbing sheet of the present disclosure, as shown in the process of FIG. 5 used in the explanation of the manufacturing method of the sound-absorbing sheet described later, a process flow can be used in which first, a foamed adsorbent sound-absorbing layer 13 is formed on a first release material 41 (FIG. 5(a)), then a second release material 42 (corresponding to release material 21 shown in FIG. 2) is formed on the foamed adsorbent sound-absorbing layer 13 (FIG. 5(b)), and then the first release material 41 is peeled off to prepare a first laminate 31B (FIG. 5(c)).

[0103] In this case, a polyolefin film, which has a lower release performance than PET, is usually used as the material constituting the release material 21. This makes it possible to prevent the release material 21 from peeling off due to vibrations or the like during the distribution process of the sound absorbing sheet 2. Also, a polyolefin film is preferable from the viewpoint of cost. As the polyolefin film, a film such as unstretched polypropylene, unstretched LDPE film, LLDPE film, etc. is selected. The thickness is selected from 20 μm to 80 μm, and 30 μm to 50 μm is preferably used.

[0104] <Method of manufacturing sound absorbing sheet> (First embodiment) FIG. 3 is a process diagram showing an example of a method for producing a sound absorbing sheet according to the present disclosure. As described above, the production of the foamed adsorption sound absorbing layer 13 requires a heating and drying step performed at 130°C or more and 200°C or less. Therefore, when the mechanically foamed (meth)acrylic acid ester polymer emulsion is applied onto a substrate, the substrate is required to have heat resistance. More specifically, when the mechanically foamed (meth)acrylic acid ester polymer emulsion is applied onto a substrate, the substrate to be used is limited to one having a melting point of 130°C or more. On the other hand, the applications of sound-absorbing sheets are expanding, and it is preferable that such temperature restrictions are not required for the base material of the sound-absorbing sheet. For example, it may be desirable for the base material of the sound-absorbing sheet to be made of a material with a melting point of less than 130°C.

[0105] Therefore, in this embodiment, a first laminate 31 is prepared in which a foamed adsorption sound-absorbing layer 13 is formed on a heat-resistant release material 21, separate from the substrate 11, and the foamed adsorption sound-absorbing layer 13 of the first laminate 31 is bonded to the substrate 11 via an adhesive layer 12, thereby producing the sound-absorbing sheet of the present disclosure.

[0106] That is, the manufacturing method of the sound-absorbing sheet of this embodiment includes a laminate preparation process of preparing a first laminate 31 in which a foamed adsorption sound-absorbing layer 13 is laminated on a release material 21, and a second laminate 32 in which an adhesive layer 12 is laminated on a substrate 11, and a bonding process of opposing the foamed adsorption sound-absorbing layer 13 of the first laminate 31 to the adhesive layer 12 of the second laminate 32 and bonding them together. This will be explained in detail below with reference to FIG.

[0107] [Laminate preparation process] In the manufacturing method of the sound-absorbing sheet of this embodiment, first, as shown in Figure 3(a), a first laminate 31 in which a foamed adsorbent sound-absorbing layer 13 is laminated on a release material 21, and a second laminate 32 in which an adhesive layer 12 is laminated on a base material 11 are prepared.

[0108] Here, in the first laminate 31, in the same manner as in the manufacturing method of the foamed adsorption sound absorbing layer 13 described above, a mechanically foamed (meth)acrylic acid ester polymer emulsion is applied to one surface of the release material 21 and then heated and dried to form the foamed adsorption sound absorbing layer 13 on the release material 21. The heating and drying temperature is 130°C or higher and 200°C or lower. Of these, a temperature of 140°C or higher and 150°C or lower is preferably used.

[0109] On the other hand, in the first laminate 31, an acrylic adhesive layer in the form of a so-called double-sided tape, both sides of which are protected by release films, is used as the adhesive layer 12, and the release film on one side is peeled off and the adhesive is bonded to the substrate 11, and then the release film on the remaining side is peeled off to obtain the first laminate 31.

[0110] [Lamination process] 3(b), the foamed adsorbent sound absorbing layer 13 of the first laminate 31 and the adhesive layer 12 of the second laminate 32 are placed opposite each other and bonded together. For example, a vacuum lamination technique can be used for this bonding step. As a result, as shown in FIG. 3(c), the sound absorbing sheet 2 having the structure shown in FIG. 2 can be obtained.

[0111] Here, the release material 21 is required to have a melting point of 130°C or higher in order to heat-dry the mechanically foamed (meth)acrylic acid ester polymer emulsion. The melting point of the release material 21 may be equal to or higher than the heat-drying temperature. Here, since the heat-drying temperature is 130°C or higher and 200°C or lower, the upper limit of the melting point of the release material 21 may be 200°C.

[0112] The foamed sound-absorbing layer 13 is bonded to the substrate 11 via an adhesive layer 12 . Therefore, adhesion between the foamed adsorption sound-absorbing layer 13 and the base material 11 can be achieved by adjusting the adhesive strength of the adhesive layer 12, and the removability of the foamed adsorption sound-absorbing layer 13, i.e., the two performances of adhesion to the adherend and removability, can be adjusted separately from the adhesion to the base material 11. For example, the adhesive strength of the adhesive layer 12 can be increased, and even if this adhesive strength is excessive, it is acceptable. And, with the foamed adsorption sound-absorbing layer 13, the optimal balance between adhesion and removability can be selected according to the adherend and the application, without being aware of the base material 11. Therefore, according to the present disclosure, it is possible to provide a sound-absorbing sheet that has both good adhesion to an adherend and good releasability.

[0113] Second embodiment Fig. 4 is a process chart showing another example of the method for producing a sound absorbing sheet according to the present disclosure, and Fig. 5 is a diagram for explaining the first laminate shown in Fig. 4. This will be explained in detail below with reference to Figures 4 and 5.

[0114] [Laminate preparation process] In the manufacturing method of the sound-absorbing sheet of this embodiment, as shown in Figure 4(a), first, a first laminate 31A is prepared in which a foamed adsorption sound-absorbing layer 13 is laminated on a first release material 41, and a second release material 42 is laminated on the foamed adsorption sound-absorbing layer 13, and a second laminate 32 is prepared in which an adhesive layer 12 is laminated on a substrate 11.

[0115] Here, in preparing the first laminate 31A, first, as shown in Fig. 5(a), in the same manner as in the manufacturing method of the foamed adsorption sound absorbing layer 13 described above, a mechanically foamed (meth)acrylic acid ester polymer emulsion is applied to one surface of a first release material 41, and then heated and dried to form a foamed adsorption sound absorbing layer 13 on the first release material 41. The heating and drying temperature is 130°C or higher and 200°C or lower. Of these, a temperature of 140°C or higher and 150°C or lower is preferably used.

[0116] Therefore, the first release material 41 is required to have a melting point of 130°C or higher in order to heat-dry the mechanically foamed (meth)acrylic acid ester polymer emulsion. The melting point of the first release material 41 may be equal to or higher than the heat-drying temperature. Here, since the heat-drying temperature is 130°C or higher and 200°C or lower, the upper limit of the melting point of the first release material 41 may be 200°C.

[0117] As described later, the first release material 41 is peeled off from the heated and dried foamed adsorbent sound absorbing layer 13. Therefore, an easy peeling layer made of silicone or the like may be provided on the surface of the first release material 41 (more specifically, the surface to which the mechanically foamed (meth)acrylic acid ester polymer emulsion is applied) for the purpose of facilitating peeling.

[0118] Next, as shown in Fig. 5(b), a second release material 42 is laminated on the heated and dried foamed adsorbent sound absorbing layer 13. In this way, a first laminate 31A shown in Fig. 4(a) is prepared. Here, since the foamed adsorbent sound absorbing layer 13 has already been heated and dried, the second release material 42 is not heated.

[0119] 5(c), the first release material 41 is peeled off from the first laminate 31A. More specifically, the first release material 41 is peeled off at the interface between the foamed adsorption sound absorbing layer 13 of the first laminate 31A and the first release material 41. This results in a first laminate 31B with the foamed adsorption sound absorbing layer 13 exposed.

[0120] [Lamination process] 4(b), the first release material 41 is peeled off from the first laminate 31A to obtain a first laminate 31B, and the exposed foamed adsorbent sound absorbing layer 13 of the first laminate 31B is placed opposite the adhesive layer 12 of the second laminate 32, and the two are bonded together. For example, a vacuum lamination technique can be used for this bonding process. As a result, as shown in Fig. 4(c), the sound absorbing sheet 2 having the configuration shown in Fig. 2 can be obtained. In this embodiment, the second release material 42 of the sound absorbing sheet 2 shown in Fig. 4(c) corresponds to the release material 21 of the sound absorbing sheet 2 having the configuration shown in Fig. 2.

[0121] <Stoma appliance> Next, the stoma appliance of the present disclosure will be described. The stoma appliance of the present disclosure is a stoma appliance having the above-mentioned sound-absorbing sheet. Here, first, the configuration of the conventional stoma appliance will be described with reference to Figs. 9 and 10, and then the configuration of the stoma appliance of the present disclosure will be described with reference to Figs. 6 to 8.

[0122] A patient who has a stoma created as an artificial anus wears a stoma appliance. In the wearer of the stoma appliance, waste discharged from the stoma is stored in a pouch (bag) of the stoma appliance. This stoma appliance basically comprises a base plate that is attached to the skin around the stoma, and a pouch that is connected to the base plate and stores waste from the stoma.

[0123] Fig. 9 shows an example of a conventional stoma appliance, where Fig. 9(a) is a schematic plan view of the stoma appliance 200 as viewed from the side where it is attached to the human body, and Fig. 9(b) is a schematic plan view of the stoma appliance 200 as viewed from the outside (i.e., the side opposite to the side where it is attached to the human body). Moreover, Fig. 10 is a diagram showing an example of a cross-sectional configuration of the stoma appliance 200 shown in Fig. 9. Here, Fig. 10(a) corresponds to a schematic plan view of Fig. 9(b), and Fig. 10(b) corresponds to a cross-sectional view taken along line ZZ of Fig. 10(a).

[0124] As shown in Figs. 9 and 10, the stoma appliance 200 includes a base plate 211 that is adhered to the skin around the stoma, and a pouch 213 that is connected to the base plate 211 and that receives waste from the stoma.

[0125] The base plate 211 has a stoma hole 212 in the approximate center, and the wearer wears the stoma appliance 200 by inserting his or her own stoma into the stoma hole 212. The base plate 211 has an adhesive layer on the surface facing the human body, and the stoma appliance 200 is worn so that no gap is created between the adhesive layer of the base plate 211 and the skin around the stoma.

[0126] The pouch 213 is connected to the base plate 211 so that there is no gap between them, and contains waste from the wearer's stoma so that it does not leak from the pouch 213. The pouch 213 has an outlet 214 on its underside (more specifically, on the ground side when a wearer wearing the stoma appliance 200 is standing upright) for discharging the contained excrement from the pouch 213. Except when discharging, this outlet 214 is closed and excrement from the stoma is stored in the pouch 213.

[0127] A clip (closure) is mainly used as a method for closing the outlet 214. For example, the wearer folds the pouch 213 near the outlet 214 and clips it to seal the outlet 214. There are also types in which a cap is provided on the outlet.

[0128] 9 and 10 is a so-called one-piece type stoma appliance in which the base plate 211 and the pouch 213 are integrated together. In addition, there is also a so-called two-piece type stoma appliance in which the base plate and the pouch are separable.

[0129] Next, the configuration of the stoma appliance of the present disclosure will be described. Fig. 6 is a diagram showing an example of a stoma appliance of the present disclosure, in which Fig. 6(a) is a schematic plan view of the stoma appliance 101 as viewed from the side where it is attached to the human body, and Fig. 6(b) is a schematic plan view of the stoma appliance 101 as viewed from the outside (i.e., the side opposite to the side where it is attached to the human body). Moreover, Fig. 7 is a diagram showing an example of a cross-sectional configuration of the stoma appliance 101 shown in Fig. 6. Here, Fig. 7(a) corresponds to a schematic plan view of Fig. 6(b), and Fig. 7(b) corresponds to a cross-sectional view taken along line AA of Fig. 7(a).

[0130] As shown in Figures 6 and 7, the stoma appliance 101 comprises a panel 111 that is adhered to the skin around the stoma, a pouch 113 that is connected to the panel 111 and that contains waste from the stoma, and a sound-absorbing sheet 1 that is attached onto the surface of the pouch 113.

[0131] This sound absorbing sheet 1 is provided to suppress noise emitted from a stoma, and has the same basic laminate structure as the sound absorbing sheet 1 shown in Fig. 1. Other components constituting the stoma appliance 101 (for example, the base plate 111 and the pouch 113) can be the same as those used in conventional stoma appliances.

[0132] In the stoma appliance 101 illustrated in Figures 6 and 7, the sound absorbing sheet 1 is removably attached onto the surface of the pouch 113 via the foamed adsorbent sound absorbing layer 13. Therefore, for example, when taking a bath, the sound absorbing sheet 1 can be easily removed from the stoma appliance 101, eliminating the problem of the sound absorbing sheet 1 getting wet. The removed sound absorbing sheet 1 can be easily attached back to the stoma appliance 101 via the foamed adsorbent sound absorbing layer 13, and by attaching the sound absorbing sheet 1, the sound emitted from the stoma can be suppressed again.

[0133] The sound absorbing sheet 1 is attached to the outer surface of the pouch 113 opposite the side connected to the base plate 111, and further preferably attached in a position that covers the stoma hole 112 provided in the base plate 111 when viewed from a direction perpendicular to the base plate 111 (for example, in the planar state shown in FIG. 6(b) or FIG. 7(a)). In such a position, the sound absorbing sheet 1 is placed directly above the stoma inserted into the stoma hole 112, and sound emitted from the stoma can be effectively suppressed.

[0134] It is known that sounds emitted from a stoma are usually generated involuntarily by the wearer and cannot be controlled by the wearer. However, the sound absorbing effect of the sound absorbing sheet 1 can be further increased by consciously pressing the sound absorbing sheet 1 from the outside with one's hand beforehand, such as after a meal, when sounds are likely to be emitted from the stoma. In other words, by pressing the sound absorbing sheet 1 more firmly against the stoma appliance 101 with one's hand, sound leakage from the sides of the sound absorbing sheet 1 can be prevented.

[0135] The base plate 111 of the stoma appliance 101 has a stoma hole 112 in the approximate center, and the wearer wears the stoma appliance 101 by inserting his / her own stoma into the stoma hole 112. The base plate 111 has an adhesive layer on the surface facing the human body, and the stoma appliance 101 is worn so that no gap is created between the adhesive layer of the base plate 111 and the skin around the stoma.

[0136] The pouch 113 is connected to the base plate 111 so that there is no gap between the pouch 113 and the base plate 111, and contains waste material from the wearer's stoma so that the waste material does not leak from the pouch 113. The pouch 113 has an outlet 114 on its underside (more specifically, on the ground side when the wearer wearing the stoma appliance 101 is standing upright) for discharging the contained excrement from the pouch 113. Except when discharging, this outlet 114 is closed and excrement from the stoma is stored in the pouch 113.

[0137] A clip (closure) is mainly used as a method for closing the outlet 114. For example, the wearer folds the pouch 113 near the outlet 114 and clips it to seal the outlet 114. There are also types in which a cap is provided on the outlet.

[0138] In addition, in Figures 6 and 7, a so-called one-piece type stoma appliance in which the base plate 111 and the pouch 113 are integrated is shown as an example of the stoma appliance 101, but the stoma appliance of the present disclosure may also be a so-called two-piece type stoma appliance in which the base plate and the pouch are separable.

[0139] (Sound absorbing sheet type) Next, a preferred embodiment of the sound-absorbing sheet used in the stoma appliance of the present disclosure will be described.

[0140] The sound absorbing sheet used in the stoma appliance of the present disclosure has, as a basic configuration, the laminated configuration of the sound absorbing sheet 1 shown in Fig. 1. However, as a detailed configuration, as shown in Fig. 8, the base material 11 has a laminated configuration in which two layers, a first base material layer 121A and a second base material layer 121B, are laminated, and the first base material layer 121A has an opening 125A at the approximate center and a cutout portion 125B at a part of the outer periphery of the first base material layer 121A, and this cutout portion 125B is preferably connected to the opening 125A. Note that an adhesive layer may be provided between the first base material layer 121A and the second base material layer 121B. As described above, the sound absorbing sheet 120 shown in Fig. 8 has a cutout portion 125B in part of the outer periphery of the first base material layer 121A, and this cutout portion 125B is connected to the opening portion 125A. Here, Fig. 8(a) is a plan view of the sound absorbing sheet 120 seen from the side of the first base material layer 121A, and Fig. 8(b) corresponds to a cross-sectional view taken along line BB in Fig. 8(a). In FIG. 8(a), the opening 125A has a circular shape with a diameter D1 (more specifically, the shape of the area surrounded by the major arc from point P1 to point P4 in the figure and the straight line (chord) connecting point P1 and point P4), and the cutout portion 125B has a trapezoidal shape (more specifically, the shape of the area surrounded by the straight line connecting point P1 and point P2, the minor arc connecting point P2 and point P3, the straight line connecting point P3 and point P4, and the straight line connecting point P4 and point P1).

[0141] Since the sound-absorbing sheet 120 shown in FIG. 8 has an opening 125A, the wearer of the stoma appliance of the present disclosure can more easily determine the attachment position of the sound-absorbing sheet 120 in the pouch 113 by aligning this opening 125A with their own stoma (convex shape) inserted into the stoma hole 112 of the panel 111.

[0142] Furthermore, in the sound absorbing sheet 1 shown in FIG. 8, a cutout portion 125B is formed in part of the outer periphery of the first base layer 121A, and this cutout portion 125B is connected to the opening portion 125A. Here, a portion of the outer periphery of the first base material layer 121A in which the cutout portion 125B is provided (i.e., the minor arc connecting points P2 and P3 in Figure 8(a)) is located on the side of the outlet 114 in the stoma appliance 101 shown in Figures 6 and 7. When the wearer attaches the sound-absorbing sheet 120 to the stoma appliance 101 shown in Figures 6 and 7, the wearer attaches the sound-absorbing sheet 120 so that a part of the outer periphery of the first base material layer 121A where the cutout portion 125B is provided (i.e., the minor arc portion connecting points P2 and P3 in Figure 8(a)) is on the side of the outlet 114 of the stoma appliance 101. In stoma appliance 101 equipped with sound-absorbing sheet 120 shown in FIG. 8, waste from the stoma moves smoothly toward outlet 114 along opening 125A and cutout 125B.

[0143] When the sound absorbing sheet 120 is attached to the stoma appliance 101, it is attached so that the side on which the opening 125A and the cutout 125B are provided (the Z direction side shown in FIG. 8(b)) faces the stoma appliance 101. Therefore, in the sound absorbing sheet 120, as shown in FIG. 8(b), a foamed adsorbent sound absorbing layer 13 is provided on the surface of the first base material layer 121A (the surface on the Z direction side shown in FIG. 8(b)) opposite the side on which the second base material layer 121B is located.

[0144] The diameter (circle-equivalent diameter) of openings 125A of sound absorbing sheet 120 can be designed according to the stoma size of the wearer, but is preferably in the range of 30 mm to 50 mm. It is preferable that the depth of the opening 125A of the sound absorbing sheet 120, i.e., the thickness (T1) of the first base material layer 121A, is greater than the thickness of the second base material layer 121B (T2 shown in FIG. 8(b)). This is because it is possible to effectively suppress the sound emitted from the stoma while reducing the weight of the sound absorbing sheet 1. It is preferable that the depth of the opening 125A, i.e., the thickness (T1) of the first base material layer 121A, is in the range of 8 mm or more and 20 mm or less. It is preferable that the thickness (T2) of the second base material layer 121B is in the range of 5 mm or more and 10 mm or less.

[0145] The length L1 (the length of the straight line connecting points P1 and P4) and length L2 (the length of the straight line (chord) connecting points P2 and P3) of the cutout portion 125B of the sound-absorbing sheet 120 shown in Figure 8(a) are determined taking into consideration the effect of suppressing the discharge sound from the stoma and the effect of smoothly moving excrement from the stoma toward the discharge port 114. For example, for the hole diameter (circle-equivalent hole diameter) D1 of the opening 125A shown in FIG. 8(a), the lengths of L1 and L2 can be in the ranges of 1 / 4×D1≦L1≦D1 and L1≦L2≦1.5×D1.

[0146] 8, a circular shape is exemplified as the planar shape of the sound-absorbing sheet 120 (more specifically, the planar shape of the outer edge of the sound-absorbing sheet 120), but the planar shape of the sound-absorbing sheet of the present disclosure can be a circle, an ellipse, or any other shape formed from curved lines. It can also be a polygon such as a rectangle or hexagon, or a polygon with curved corners. Furthermore, it can be any shape including straight lines and curved lines. The sound-absorbing sheet preferably has an equivalent circle diameter in the range of 50 mm to 150 mm in order to maximize the effects of the present disclosure. The equivalent circle diameter is the diameter of a circle having the same area as the planar shape of the sound-absorbing sheet. Furthermore, the sound absorbing sheet is required to be lightweight, preferably weighing 50 g or less per sheet.

[0147] At least a part of the peripheral edge of the sound absorbing sheet may be covered with any appropriate layer as long as the effect of the present disclosure is not impaired. In addition, the peripheral edge of the sound absorbing sheet may be covered by deforming the cross-sectional shape by pressing or the like. EXAMPLES

[0148] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples. The property values ​​in the examples were measured by the following methods.

[0149] Example 1 The sound absorbing sheet of Example 1 was produced according to the following procedure.

[0150] (Production of foamed sound-absorbing layers) [Mechanical foaming process] 1% by mass of a thickener and 4% by mass of a foam stabilizer ("Nopco DC-100-A" manufactured by San Nopco Ltd.) were added to the (meth)acrylic acid ester polymer emulsion, and the mixture was uniformly stirred for 10 minutes with a stirrer. Next, the mixture was foamed for 5 minutes at a stirring speed of 125 rpm in the air at room temperature of about 23°C with a batch type foaming machine ("Mixing Stirrer 5DM-r" manufactured by Dalton Co., Ltd., stirring tool: whipper) to obtain a mechanically foamed liquid of a (meth)acrylic acid ester polymer emulsion with a specific gravity of 0.3.

[0151] [Coating process] As shown in FIG. 3, a spacer frame (thickness: 150 μm) for setting the thickness was placed on top of the release PET as the release material 21, and the mechanical foaming liquid of the emulsion obtained above was poured in. Next, a stainless steel ruler was used to remove excess foaming liquid along the spacer thickness, thereby obtaining a coating layer adjusted to a thickness of 150 μm.

[0152] [Heat drying process] The laminate (coating layer / release material) including the coating layer formed above was dried by heating in a hot air circulation oven ("DH611" manufactured by Yamato Scientific Co., Ltd.) at a temperature of 150°C and a damper opening of 50%, to obtain a laminate having a foamed adsorption sound absorbing layer on the release PET. The thickness of the foamed adsorption sound absorbing layer formed was 150μm, the expansion ratio was 2.0 times, and the basis weight of the foamed adsorption sound absorbing layer was 60g / m 2 The heat drying time was 40 minutes or less. Note that this heat drying time is the time required until the dispersion medium is substantially no longer observed in the foamed adsorbent sound absorbing layer.

[0153] The thickness of the foamed sound-absorbing layer was determined by measuring the cross section cut out by a cutting machine with an optical microscope. The expansion ratio of the foamed adsorption sound-absorbing layer was determined as the ratio (Vb / Va) of the volume Va per unit mass (e.g., 100 g) of the (meth)acrylic ester polymer emulsion after mechanical foaming and after being heated and dried to the volume Vb per unit mass (e.g., 100 g) of the (meth)acrylic ester polymer emulsion after mechanical foaming and after being heated and dried.

[0154] In addition, the basis weight of the foamed adsorption sound-absorbing layer was determined as follows for a laminate (corresponding to the first laminate 31 shown in Figure 3) having a foamed adsorption sound-absorbing layer on a release PET prepared in the process of manufacturing the sound-absorbing sheet.

[0155] [Release PET weight] The release PET was cut into pieces measuring 10 cm x 10 cm, and left unloaded for 24 hours at a temperature of 23°C and a humidity of 50% RH. The mass W1 (g) was then measured, and the basis weight A (g / m2) of the release PET was calculated by dividing W1 by 0.01. 2 ) was sought. The "weight" of the release PET mentioned above refers to the weight per unit area of ​​the release PET, and is usually calculated based on the weight per unit area per 1 m 2 The weight of the hit is expressed in grams.

[0156] [Weight of foamed sound absorbing layer] The laminate having a foamed adsorption sound absorbing layer on the release PET was cut into a size of 10 cm x 10 cm, and left for 24 hours at a temperature of 23°C and a humidity of 50% RH without load, after which the mass W2 (g) was measured, and the basis weight B (total basis weight: g / m2) of the laminate having a foamed adsorption sound absorbing layer on the release PET was calculated by W2 / 0.01. 2 ) was sought. The basis weight A (g / m2) of the release PET measured above was calculated from the basis weight B obtained. 2 ) to obtain the basis weight C (g / m 2 That is, the basis weight C was calculated from C = BA.

[0157] (Manufacture of sound absorbing sheets) As the sound absorbing sheet of Example 1, a sound absorbing sheet having the configuration shown in FIG. 8 was manufactured. First, a foamed urethane sheet Rubilar L31 manufactured by Toyo Polymer Co., Ltd. was used as the base material for the sound-absorbing sheet, and a base material was produced having two layers, a first base material layer 121A and a second base material layer 121B, as in sound-absorbing sheet 120 shown in Fig. 8, in which first base material layer 121A has a cutout portion 125B in a part of the outer periphery, and this cutout portion 125B is connected to opening 125A. Here, the thickness (T1) of first base material layer 121A was 13 mm, and the thickness (T2) of second base material layer 121B was 7 mm. Next, an acrylic adhesive (50 μm thick) composed of a (meth)acrylic acid ester copolymer was formed as an adhesive layer on the first base material layer 121A of the two-layered base material thus produced, to produce a laminate corresponding to the second laminate 32 shown in Fig. 3. A highly adhesive adhesive sheet was used for this acrylic adhesive, and the lamination strength between the base material and the adhesive sheet, and between the foamed adsorption sound absorbing layer and the adhesive sheet was 10 N / 25 mm or more. Thereafter, the adhesive layer of this laminate (corresponding to the second laminate 32 shown in Figure 3) was bonded to the foamed adsorption sound-absorbing layer of the laminate (corresponding to the first laminate 31 shown in Figure 3) on which the above-mentioned foamed adsorption sound-absorbing layer had been formed, thereby producing the sound-absorbing sheet of Example 1.

[0158] Example 2 The sound-absorbing sheet of Example 2 was manufactured in the same manner as in Example 1, except that the spacer frame for setting the thickness of the foamed adsorption sound-absorbing layer was set to a thickness of 200 μm and the heating and drying time was set according to this thickness. The thickness of the foamed sound-absorbing layer is 200μm, the foaming ratio is 2.0 times, and the weight of the foamed sound-absorbing layer is 63g / m 2 The heat drying time was 40 minutes or less.

[0159] Example 3 The sound-absorbing sheet of Example 3 was manufactured in the same manner as in Example 1, except that the stirring rotation speed of the batch type foaming machine in the mechanical foaming step of manufacturing the foamed adsorption sound-absorbing layer was set to 250 rpm, the spacer frame for setting the thickness of the foamed adsorption sound-absorbing layer was set to a thickness of 500 μm, and the heating and drying time was set according to this thickness. The thickness of the foamed sound-absorbing layer is 500μm, the foaming ratio is 4.0 times, and the weight of the foamed sound-absorbing layer is 80g / m 2 The heat drying time was 40 minutes or less.

[0160] Example 4 The sound-absorbing sheet of Example 4 was manufactured in the same manner as in Example 1, except that the stirring rotation speed of the batch type foaming machine in the mechanical foaming step of manufacturing the foamed adsorption sound-absorbing layer was set to 180 rpm, the spacer frame for setting the thickness of the foamed adsorption sound-absorbing layer was set to a thickness of 5000 μm, and the heating and drying time was set according to this thickness. The thickness of the foamed sound-absorbing layer is 5000μm, the foaming ratio is 3.0 times, and the weight of the foamed sound-absorbing layer is 600g / m 2 The heating and drying time was more than 40 minutes and less than 60 minutes.

[0161] Comparative Example 1 The sound-absorbing sheet of Comparative Example 1 was manufactured in the same manner as in Example 1, except that the spacer frame for setting the thickness of the foamed adsorption sound-absorbing layer was set to a thickness of 100 μm and the heating and drying time was set according to this thickness. The thickness of the foamed sound-absorbing layer is 100μm, the foaming ratio is 2.0 times, and the weight of the foamed sound-absorbing layer is 52g / m 2 The heat drying time was 40 minutes or less.

[0162] Comparative Example 2 The sound-absorbing sheet of Comparative Example 2 was manufactured in the same manner as in Example 1, except that the stirring rotation speed of the batch type foaming machine in the mechanical foaming step of manufacturing the foamed adsorption sound-absorbing layer was set to 180 rpm, the spacer frame for setting the thickness of the foamed adsorption sound-absorbing layer was set to a thickness of 6000 μm, and the heating and drying time was set according to this thickness. The thickness of the foamed sound-absorbing layer is 6000μm, the foaming ratio is 3.0 times, and the weight of the foamed sound-absorbing layer is 700g / m 2 In addition, the heat drying time required more than 60 minutes.

[0163] (evaluation) [Peel strength and peelability] The peel strength and peelability of the foamed adsorption sound absorbing layer of each sound absorbing sheet was evaluated for Examples 1 to 4 and Comparative Examples 1 and 2. The results are shown in Table 1. Here, the adherend used was a LLDPE (Linear Low Density Polyethylene) sheet (100 μm thick) of the same grade as the material constituting the pouch of the stoma appliance. The peel strength of this foamed adsorption sound absorbing layer corresponds to the adhesive strength of the foamed adsorption sound absorbing layer.

[0164] The peel strength was measured under the following conditions by attaching each sound absorbing sheet to an LLDPE sheet with a width of 25 mm and peeling it off in a 180° direction (unit: N / 25 mm). The peel strength shown in Table 1 was judged according to the following criteria.

[0165] (conditions) Pressing method: 2kg roller, 1 round trip Pressure bonding temperature: 23℃ / 50%RH Curing conditions: Room temperature (23℃ / 50%RH) x 30min Tensile speed: 300mm / min Pull angle: 180° Measurement temperature: Room temperature (23℃ / 50%RH)

[0166] (Criteria for Peel Strength) ◎: Excellent peel strength ◯: Good peel strength

[0167] The releasability shown in Table 1 was evaluated by visually inspecting the adherend surface and the foamed adsorbent sound absorbing layer after the sound absorbing sheet was peeled off from the adherend, according to the following criteria.

[0168] (Criteria for peelability) ◎: No residual foamed sound-absorbing layer remains on the adherend, and the foamed sound-absorbing layer of the sound-absorbing sheet is in good condition ◯: No remaining foamed sound-absorbing layer is observed on the adherend, but wrinkles are observed in the foamed sound-absorbing layer of the sound-absorbing sheet.

[0169] [Productivity] The productivity of each of the sound absorbing sheets of Examples 1 to 4 and Comparative Examples 1 and 2 was evaluated based on the length of the heat drying time. The results are shown in Table 1. The heat drying time is the time required until substantially no dispersion medium is observed in the foamed adsorbent sound absorbing layer. The productivity shown in Table 1 was judged according to the following criteria.

[0170] (Productivity criteria) ◎: Heat drying time is 40 minutes or less ○: Heat drying time is more than 40 minutes and less than 60 minutes ×: Heat drying time exceeds 60 minutes

[0171] [Sound insulation] The sound absorbing properties of each of the sound absorbing sheets of Examples 1 to 4 and Comparative Examples 1 and 2 were evaluated. The results are shown in Table 1. The sound insulation was measured as follows: White noise was used as the sound source, and the sound pressure that reached the microphone through the base material alone or each sound-absorbing sheet was analyzed to obtain the RMS value (Root Mean Square value) at frequencies from 25 Hz to 10,000 Hz. Here, the RMS value of the environmental sound in the frequency range of 25 Hz to 10,000 Hz was 58.6 (dB), and the RMS value of the white noise was 58.6 (dB). The above-mentioned substrate alone refers to the form of only the substrate obtained by removing the adhesive layer (corresponding to the adhesive layer 12 in the sound-absorbing sheet 120 shown in FIG. 8) and the foamed adsorption sound-absorbing layer (corresponding to the foamed adsorption sound-absorbing layer 13 in the sound-absorbing sheet 120 shown in FIG. 8) from the sound-absorbing sheet of Example 1.

[0172] (Measurement conditions) Distance from sound source to microphone: 50mm Microphone: Free-field microphone 352B02 manufactured by PCB and sold by Toyo Corporation was used. Sound pressure analysis: Analyzing sound pressure at 25Hz frequency intervals using an FFT analyzer manufactured by OROS, sold by Toyo Corporation

[0173] Next, the sound absorption efficiency (%) of each sound absorbing sheet was calculated from each RMS value obtained. This sound absorption efficiency (%) was calculated from the following formula, where the RMS value of the base material alone is Ra and the RMS value of each sound absorbing sheet is Rx. Sound absorption efficiency (%) = 100 x (Ra-Rx) / Ra The RMS values ​​for the substrate alone and each sound-absorbing sheet are shown in Table 2. The sound insulation properties shown in Table 1 were judged based on the sound absorption efficiency shown in Table 2 according to the following criteria.

[0174] (Sound insulation evaluation criteria) ◎: Sound absorption efficiency is 2.5% or more 〇: Sound absorption efficiency is 1% or more but less than 2.5% ×: Sound absorption efficiency is less than 1%

[0175] [Table 1]

[0176] [Table 2]

[0177] As can be seen from Table 1, the sound absorbing sheets of Examples 1 to 4 all showed good results in terms of peel strength, releasability, productivity and sound insulation. In particular, the sound absorbing sheet of Example 3 showed excellent results in terms of peel strength, releasability, productivity and sound insulation. Here, the sound absorbing sheets of Examples 1 to 4 each had a foamed adsorption sound absorbing layer thickness that was in the range of 150 μm or more and 5000 μm or less. Also, the sound absorbing sheets of Examples 1 to 4 each had a foamed adsorption sound absorbing layer basis weight of 60 g / m 2 More than 600g / m 2 The following range was satisfied: Furthermore, in each of the sound absorbing sheets of Examples 1 to 4, the foaming ratio of the foamed, adsorbent sound absorbing layer was in the range of 2.0 or more and 4.0 or less.

[0178] On the other hand, from Table 1, the sound absorbing sheet of Comparative Example 1, in which the thickness of the foamed adsorption sound absorbing layer was thinner than each of the sound absorbing sheets of Examples 1 to 4, had inferior sound insulation properties to each of the sound absorbing sheets of Examples 1 to 4. Here, the thickness of the foamed adsorption sound absorbing layer of the sound absorbing sheet of Comparative Example 1 was 100 μm, and the basis weight of the foamed adsorption sound absorbing layer was 52 g / m 2 It was.

[0179] Furthermore, as can be seen from Table 1, the sound absorbing sheet of Comparative Example 2, in which the foamed adsorption sound absorbing layer was thicker than the sound absorbing sheets of Examples 1-4, was inferior in productivity to the sound absorbing sheets of Examples 1-4. Here, the thickness of the foamed sound-absorbing layer of the sound-absorbing sheet of Comparative Example 2 is 6000 μm, and the basis weight of the foamed sound-absorbing layer is 700 g / m 2 It was.

[0180] As described above, the sound absorbing sheets according to the present disclosure illustrated in Examples 1 to 4 all showed good results in terms of peel strength, releasability, productivity, and sound insulation. Therefore, the sound absorbing sheets according to the present disclosure illustrated in Examples 1 to 4 can be suitably used in stoma appliances as a removable sound absorbing mechanism. Furthermore, in a stoma appliance using the sound-absorbing sheet according to the present disclosure, the sound-absorbing sheet can be easily attached and detached, and when the sound-absorbing sheet is worn, the sound emitted from the stoma can be effectively reduced.

[0181] Although the respective embodiments of the sound-absorbing sheet and stoma appliance according to the present disclosure have been described above, the present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and anything that has substantially the same configuration as the technical idea of ​​the present disclosure and provides similar effects is included in the technical scope of the present disclosure in any case. [Explanation of symbols]

[0182] 1, 2 Sound absorbing sheet 11 Base material 12 Adhesive layer 13 Foamed sound-absorbing layer 21 Release material 31, 31A, 31B First laminate 32 Second laminate 41 First release agent 42 Second release agent 101 Stoma appliances 111 Face plate 112 Stoma hole 113 Pouch 114 Outlet 120 Sound absorbing sheet 121A first substrate layer 121B second substrate layer 125A opening 125B Notch 200 Stoma appliances 211 Face plate 212 Stoma hole 213 Pouch 214 Outlet

Claims

1. It has a laminated structure in which an adhesive layer and a foamed sound-absorbing layer are laminated in this order on a base material, the foamed sound-absorbing layer is made of a foamed (meth)acrylic acid ester polymer, The thickness of the foamed sound-absorbing layer is 150 μm or more and 5000 μm or less, The substrate has a laminated structure in which a first substrate layer and a second substrate layer are laminated, the first base layer has an opening; The first base layer has a notch in a part of an outer periphery thereof, The cutout portion is connected to the opening, A sound-absorbing sheet, comprising the foamed adsorbent sound-absorbing layer provided on a side of the first base material layer opposite to the side on which the second base material layer is located.

2. The foamed sound-absorbing layer has a basis weight of 60 g / m ２ 600g / m or more ２ The sound-absorbing sheet according to claim 1 , wherein:

3. 3. The sound absorbing sheet according to claim 1, wherein the foaming ratio of the foamed, adsorbent, sound absorbing layer is 2.0 or more and 4.0 or less.

4. The sound absorbing sheet according to claim 1 , wherein the adhesive layer is made of a (meth)acrylic acid ester copolymer.

5. The sound absorbing sheet according to claim 1 , wherein the substrate comprises a polyurethane foam.

6. The sound absorbing sheet according to claim 1 , wherein the first base material layer has a thickness greater than a thickness of the second base material layer.

7. A base plate that is attached to the skin around the stoma and has a stoma hole through which the stoma is inserted; a pouch connected to the base plate for receiving waste from the stoma; A sound absorbing sheet attached onto the surface of the pouch; Equipped with The sound absorbing sheet is It has a laminated structure in which an adhesive layer and a foamed sound-absorbing layer are laminated in this order on a base material, the foamed sound-absorbing layer is made of a foamed (meth)acrylic acid ester polymer, The thickness of the foamed sound-absorbing layer is 150 μm or more and 5000 μm or less, A stoma appliance in which the sound-absorbing sheet is removably attached onto the surface of the pouch on the side of the foam-adsorbent sound-absorbing layer.

8. The stoma appliance according to claim 7, wherein the sound-absorbing sheet is attached in a position covering the stoma hole when viewed from a direction perpendicular to the base plate.

Images