Filter structure

Abstract

A filter structure (81) is attached to an object (74) to filter a gas passing therethrough, and comprises: a filter layer constituted of a sheet-like member that is air-permeable; and a printing layer formed on at least a portion of at least one surface of the filter layer. The printing layer contains 2.0-45 wt% of a first flame retardant. Because designability is imparted to the filter structure (81) and flame retardancy is imparted to the filter layer provided with the printed layer, the designability of the filter structure (81) is improved and the flame retardancy of the filter layer is improved.

Description

Filter Structure

[0001] The present invention relates to a filter structure, and more particularly to a filter structure that is attached to an object such as a range hood, an air conditioner, an air purifier, or a vent, for filtering gas passing through.

[0002] Filter structures for attaching to metal filters or rectifiers of range hoods, air intakes of air conditioners or air purifiers, indoor and outdoor vents, etc., to filter the air passing through are described in Japanese Patent Application Laid-Open No. 2002-85927 (Patent Document 1), Japanese Patent Application Laid-Open No. 2017-15297 (Patent Document 2), etc. The filter structures described in these documents have a structure in which an adhesive layer is formed on one side of a sheet-like filter layer made of nonwoven fabric or the like. A thin release sheet is typically attached to the surface of the adhesive layer. Furthermore, Japanese Patent Application Laid-Open No. 10-43528 (Patent Document 3) describes a filter material for ventilation fans, which has a width dimension greater than the width dimension of the exhaust opening of the ventilation hood and a length dimension greater than the length dimension of the exhaust opening of the ventilation hood, and in which linear printing is applied in the width and length directions on the filter surface to serve as a guide during cutting.

[0003] Japanese Unexamined Patent Publication No. 2002-85927 Japanese Unexamined Patent Publication No. 2017-15297 Unexamined Japanese Patent Publication No. 10-43528

[0004] To attach a filter structure such as those described in Patent Documents 1 and 2 to a target such as a range hood, the release film attached to the surface of the adhesive layer is removed to expose the adhesive surface of the adhesive layer, and the adhesive surface is then aligned with the mounting location and pressed down to attach the filter structure. When attaching a filter structure such as those described in Patent Documents 1 and 2 to a range hood or the like installed on a kitchen gas range, flame-retardant fibers are used as the fibers constituting the nonwoven fabric, or the fibers are treated with a flame retardant (e.g., by attaching a fatty acid metal salt such as aluminum stearate to the fibers). Such flame-retardant properties prevent the filter structure from coming into direct contact with flames during normal kitchen cooking, so the filter structure does not easily melt or burn due to the heat of cooking. However, when cooking food using a method known as flambé, in which high-alcohol liquor such as brandy is dropped into a frying pan to quickly evaporate the alcohol, the evaporated alcohol can cause large flames to form. In such cases, flames may come into direct contact with the filter structure, potentially catching fire on the nonwoven fabric that constitutes the filter structure. However, if the nonwoven fabric is rendered flame-retardant as described above, the nonwoven fabric itself will be less flammable. On the other hand, since such nonwoven fabrics are generally white and not particularly decorative, there is a demand for printing highly decorative figures, patterns, and colored designs on the nonwoven fabric. To meet this demand, it is conceivable to use nonwoven fabrics composed of fibers with pigments kneaded into the fibers themselves. However, such nonwoven fabrics are typically monochromatic, making it difficult to impart desired designs, such as figures and patterns, to the nonwoven fabric. Therefore, when imparting design to a nonwoven fabric, it is preferable to print the desired figures, patterns, and other designs on the nonwoven fabric by applying printing ink to the nonwoven fabric, and to maximize the design potential of the printed design, it is preferable to print on the surface of the nonwoven fabric (the side opposite to the side that will be attached to the target, such as a range hood).However, when printing ink is applied to a nonwoven fabric, the printing ink covers the surface of the nonwoven fabric. Such printing inks are primarily composed of colorant components such as pigments, resin components that fix the colorant components to the nonwoven fabric fibers, and solvents that dissolve the resin components. After the printing ink is applied to the nonwoven fabric and dried, the solvent is evaporated and removed from the printed layer, but the colorant components and resin components remain intact on the nonwoven fabric. These resin components may burn if directly exposed to flame. Furthermore, some colorant components (e.g., carbon black) may also promote combustion of the nonwoven fabric if directly exposed to flame. This is because, if a printed layer is formed on the nonwoven fabric, even if the nonwoven fabric itself is rendered flame-retardant as described above, the flame will first come into contact with the printed layer when the nonwoven fabric comes into direct contact with flame. Therefore, the combustion of the printed layer will hinder the flame-retardant function of the nonwoven fabric, resulting in the risk of the nonwoven fabric constituting the filter structure burning. Due to these issues, there are no filter structures on the market that have a printed layer to impart design to the nonwoven fabric, except for those with linear printing that simply serves as a cutting guide, as described in Patent Document 3. Similarly, when a filter structure employs a configuration in which an adhesive layer is formed on one side of the nonwoven fabric, the adhesive layer is made of a resin-based adhesive or a rubber-based adhesive, which is flammable. However, when attached to a range hood or the like, the nonwoven fabric is on the opposite side of the adhesive layer, which is located furthest from the gas stove, so it would seem that the adhesive layer would not burn unless the nonwoven fabric itself burns. However, contrary to this expectation, it has been found that when an adhesive layer is sprayed onto the entire surface of one side of the nonwoven fabric, the filter structure can easily burn when the flame comes into direct contact with the filter structure, as in a flambé.The reason for this is not clear, but it is thought that when an adhesive layer is sprayed onto the entire surface of one side of a nonwoven fabric, the adhesive is scattered all over the surface of that side, covering some or most of the fibers that make up the nonwoven fabric.If a flame comes into contact with the adhesive that covers the fibers of the nonwoven fabric and spreads to the adhesive, or if the flame passes through the gaps between the fibers and reaches the adhesive layer and spreads, the fire will spread throughout the nonwoven fabric before the flame retardancy can be exerted, even if the nonwoven fabric has been given flame retardancy.

[0005] In view of the above-mentioned conventional problems, the present invention aims to provide a filter structure that maintains the flame retardancy of the entire filter structure even when a printed layer is formed on the filter structure for the purpose of adding design to the filter structure.

[0006] In order to achieve the above object, a filter structure in a first aspect of the present invention is a filter structure for attaching to an object to filter gas passing through, and comprises a filter layer made of a breathable sheet-like member and a printed layer formed on at least a portion of one side of the filter layer, and the printed layer contains 2.0% by weight or more and 45% by weight or less of a first flame retardant.

[0007] By configuring in this manner, effect 1 can be obtained, in which design is imparted to the filter structure and flame retardancy is imparted to the filter layer provided with the printed layer.

[0008] A filter structure according to a second aspect of the present invention is the same as that according to the first aspect of the invention, in which the printed layer contains 9% by weight or more and 30% by weight or less of the first flame retardant.

[0009] With this configuration, effect 2 can be achieved, in which the flame retardancy of the filter layer provided with the printed layer is further improved.

[0010] In a third aspect of the present invention, in the configuration of the first or second aspect of the invention, the filter structure is characterized in that the printed layer is formed on the filter layer at a thickness of 0.1 g / m ２ 10g / m or more ２ It is formed in the following range.

[0011] With this configuration, effect 3 can be obtained, that is, the filter structure can be given a high level of designability.

[0012] The filter structure in a fourth aspect of the present invention has the configuration of the invention in the first or second aspect, and further comprises an adhesive layer formed on at least a part of the other surface of the filter layer for adhering to an object, the adhesive layer containing 3 wt % or more of a second flame retardant.

[0013] With this configuration, effect 4 can be achieved, that is, the pressure-sensitive adhesive layer is also imparted with flame retardancy.

[0014] A filter structure in a fifth aspect of the present invention is the same as that in the fourth aspect of the invention, wherein the pressure-sensitive adhesive layer contains 10% by weight or more and 30% by weight or less of a second flame retardant.

[0015] This configuration provides effect 5, in which the flame retardancy of the adhesive layer is further improved and the necessary adhesive strength can be secured when the filter structure is attached to an object to be attached.

[0016] In a sixth aspect of the present invention, there is provided a filter structure according to the fourth aspect of the present invention, wherein the pressure-sensitive adhesive layer is formed on the filter layer at a density of 5 g / m2. ２ 50g / m or more ２ It is formed in the following range.

[0017] With this configuration, an effect 6 can be obtained in which the necessary adhesive strength can be secured when the filter structure is attached to an object to be attached.

[0018] A filter structure according to a seventh aspect of the present invention is the filter structure according to the fourth aspect of the invention, wherein both the first flame retardant and the second flame retardant are organic non-halogen flame retardants.

[0019] With this configuration, effect 7 can be achieved in that any of the flame retardants is unlikely to generate toxic gases due to thermal decomposition of the flame retardant.

[0020] In an eighth aspect of the present invention, there is provided a filter structure according to the first or second aspect of the present invention, wherein one surface of the filter layer, which corresponds to the surface of the filter layer on which the printed layer is formed, is classified as category 3 in a flammability test according to JIS L 1091 A-1 method (45° microburner method).

[0021] With this configuration, an effect 8 can be obtained in which one side of the filter layer is flame-resistant.

[0022] A ninth aspect of the present invention provides a filter structure according to the first or second aspect of the present invention, wherein the object is a range hood.

[0023] With this configuration, the flame retardancy is high, so that the product can be used more safely even when using fire on a gas stove, which is an effect 9.

[0024] As described above, the filter structure according to the first aspect of the present invention provides the above-mentioned effect 1, and therefore the design of the filter structure is improved and the flame retardancy of the filter layer is also improved.

[0025] The filter structure according to the second aspect of the present invention provides the above-mentioned effect 2 in addition to the effect of the first aspect of the invention, and therefore the flame retardancy of the filter layer is further improved.

[0026] The filter structure according to the third aspect of the present invention provides the above-mentioned effect 3 in addition to the effects of the first or second aspect of the invention, and therefore the design of the filter structure is further improved.

[0027] The filter structure according to the fourth aspect of the present invention provides the above-mentioned effect 4 in addition to the effects of the first or second aspect of the present invention, thereby improving the flame retardancy of the entire filter structure.

[0028] The filter structure according to the fifth aspect of the present invention has the effect of the invention according to the fourth aspect as well as the effect 5 described above, thereby further improving the flame retardancy of the entire filter structure and suppressing peeling or falling off of the filter structure.

[0029] The filter structure according to the sixth aspect of the present invention has the effect of the fourth aspect of the invention as well as the above-mentioned effect 6, so that the filter structure is prevented from peeling off or falling off, and the filtration of gas through the filter layer is not hindered.

[0030] The filter structure according to the seventh aspect of the present invention provides the above-mentioned effect 7 in addition to the effect of the invention according to the fourth aspect, and therefore is safer for the human body.

[0031] The filter structure according to the eighth aspect of the present invention provides the effect 8 in addition to the effects of the first or second aspect of the invention, and therefore the flame retardancy of the entire filter structure is improved.

[0032] The filter structure according to the ninth aspect of the present invention can obtain the above-mentioned Action 9 in addition to the effects of the invention according to the first or second aspect, and therefore can be suitably used in a range hood.

[0033] 1 is a diagram showing an example of a case where a filter structure according to an embodiment of the present invention is attached to a metal filter of a range hood.

[0034] FIG. 1 is a diagram showing an example of a case where a filter structure according to an embodiment of the present invention is attached to a metal filter of a range hood.

[0035] Referring to the figure, the range hood is comprised of a boot-shaped hood with an air intake on the inside. A metal filter 74 is attached to the opening of the air intake to prevent foreign matter from entering the interior of the air intake. The outer surface of the metal filter 74 has a rectangular shape with a pair of opposing sides and a pair of opposing sides.

[0036] The filter structure 81 includes a filter layer made of a breathable sheet-like material and an adhesive layer formed on at least a portion of the other surface of the filter layer (the surface to be attached to the object) for adhering to the object. The filter structure 81 is cut to a predetermined length to fit the size of the metal filter 74. To facilitate cutting, perforations 82 are formed at predetermined intervals across the width. These perforations 82 can be omitted as needed. The filter structure 81 may be pre-cut to the desired size, or a rolled filter structure 81 may be cut appropriately for use. While the filter structure typically has a rectangular shape, it may also have a shape other than rectangular, such as a shape corresponding to the outer shape of the gas inlet of the object to which it is attached, such as a metal filter. The size of the filter structure 81 is not particularly limited as long as it is large enough to cover the gas inlet of the object to which it is attached. Furthermore, the object to which the filter structure 81 is attached is not limited to the metal filter of a range hood.

[0037] As described above, an adhesive layer (not shown) is formed on the other surface of the filter structure 81 by applying an adhesive (not shown). The filter structure may not have an adhesive layer. If an adhesive layer is not provided, the filter structure is attached to the attachment target by an attachment means other than the adhesive layer. Examples of attachment means other than the adhesive layer include adhesive tape, adhesive, magnets, clips, screws, and support frames that are separate from the filter structure.

[0038] This filter structure 81 is attached to an object by adhesion to filter passing gas, and comprises a sheet-like filter layer S that filters the passing air, and a printed layer D formed on at least a portion of one side of the filter layer S. By providing this printed layer, a desired figure, pattern, or other design can be printed on the filter layer S, thereby imparting designability to the filter structure 81. In addition, the other side of the filter layer S is provided with an adhesive layer N for attachment to the object. In addition, before use, a peelable release sheet layer is laminated on the surface of the adhesive layer N, and when in use, the release sheet layer is peeled off and the filter structure 81 is attached to the object in the same way as a sticker is applied.

[0039] The filter layer S in this example is made of, for example, nonwoven fabric, woven fabric, knitted fabric, etc. In order to achieve both the collection of oily smoke, dust, etc. and the circulation of gas, and to ensure practical strength, the thickness is 0.3 mm to 15.0 mm, and the basis weight is 20 g / m ２ More than 200g / m ２ The thickness is preferably in the following range: less than 0.3 mm, or the basis weight is 20 g / m ２ If the thickness is less than 15.0 mm, the strength may be insufficient for practical use, and the collection function may not be sufficiently exhibited. ２ If the resistance exceeds this value, the gas flow resistance increases, which may impair the practicality of the air filter. Examples of materials that can be used for the filter layer S include, but are not limited to, polyesters such as PET, polypropylene or propylene-based copolymers, and acrylics including modacrylic. When the filter structure of the present invention is used as a filter structure for a range hood, the filter layer S, for example, if made of a nonwoven fabric, preferably uses flame-retardant fibers as the constituent fibers or treats the fibers with a flame retardant (for example, by attaching a fatty acid metal salt such as aluminum stearate to the fibers). Furthermore, the filter layer S may be treated to exhibit antiviral, antibacterial, antifungal, or other functions in addition to flame retardancy.

[0040] However, regardless of the flame retardancy of the filter layer S itself and the presence or absence and degree of flame retardant treatment (e.g., attachment or incorporation of a flame retardant) on the filter layer S, the flame retardancy of the printing layer D and the adhesive layer N described below can prevent or suppress combustion of the filter layer S.

[0041] The printed layer D is formed on at least a portion of one surface of the filter layer S. The printing ink that forms the printed layer D is not particularly limited and is mainly composed of a colorant component such as a pigment, a resin component that fixes the colorant component to the nonwoven fabric fibers, and a solvent that dissolves the resin component. As the colorant component that constitutes the printing ink, for example, organic pigments, inorganic pigments, dyes, luster pigments, resin powders, etc. may be used. These may be used alone or in combination of two or more types. Examples of organic pigments include Red 201, Red 202, Red 204, Red 205, Red 220, Red 226, Red 228, Red 305, Orange 203, Orange 204, Yellow 205, Yellow 401, and Blue 404, as well as Red 3, Red 104, Red 106, Red 227, Red 230, Red 401, Red 505, Orange 205, Yellow 4, Yellow 5, Yellow 202, Yellow 203, Green 3, and Blue 1, and zirconium lake, barium lake, or aluminum lake versions of these organic pigments. Examples of inorganic pigments include silica, talc, mica, ceramic, clay minerals, zinc oxide, alumina, magnesium oxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, strontium sulfate, zeolite, calcium phosphate, glass powder, ferric iron ferrous ... Examples of pearl pigments include, but are not limited to, titanium mica, red iron oxide-coated mica, red iron oxide-coated mica titanium, carmine-coated mica titanium, Prussian blue-coated mica titanium, titanium oxide-coated synthetic phlogopite, red iron oxide-coated synthetic phlogopite, titanium oxide-coated glass flakes, titanium oxide-coated alumina flakes, titanium oxide-coated silica flakes, silica-coated aluminum, iron oxide-silica-coated aluminum, and silica-coated iron.Preferred examples of metallic pigments include aluminum, copper, zinc, titanium, iron, nickel, chromium, and alloys thereof, as well as metal-coated glass flakes. Furthermore, these metallic pigments may have a resin layer or an inorganic layer formed on their surfaces. Examples of resin powders include powders and spherical or non-spherical spheres of nylon resin, acrylic or methacrylic resins such as polymethyl methacrylate and acrylonitrile-methacrylic acid copolymer, silicone resins such as vinylidene chloride-methacrylic acid copolymer, urethane, polyethylene, polystyrene, and organopolysiloxane elastomer, polymethylsilsesquioxane, polytetrafluoroethylene, wool, silk, crystalline cellulose, magnesium stearate, zinc stearate, and N-acylysine. The solid content of the colorant component contained in the printing layer D (i.e., the coating film after the printing ink has solidified and dried) is not particularly limited, but may be, for example, 5% by weight to 45% by weight, more preferably 9% by weight to 42% by weight. Within this range, it is possible to impart the desired design to the filter structure 81. Furthermore, resin components constituting the printing ink include, for example, acrylic resins, alkyd resins, rosin resins, epoxy resins, urethane resins, amide resins, polyamideimide resins, and cellulose-based resins such as nitrocellulose. These may be used alone or in combination of two or more. The solid content of the resin component contained in the printing layer D is not particularly limited, but may be, for example, 5% by weight to 85% by weight, and more preferably 9% by weight to 83% by weight. Within this range, it is possible to prevent the printing layer from falling off from the fibers of the nonwoven fabric and to reliably adhere the first flame retardant contained in the printing layer (described below) to the fibers of the nonwoven fabric. In other words, the resin component contained in the printing ink acts to fix not only the colorant component but also the first flame retardant to the fibers of the nonwoven fabric, etc., constituting the filter layer S.Therefore, the first flame retardant contained in the printing ink adheres better to fibers such as nonwoven fabric and is more reliably fixed than a flame retardant that is directly attached to fibers such as nonwoven fabric, and efficiently contributes to improving the flame retardancy of the entire filter structure 81.

[0042] Examples of solvents that can be used to form printing inks include organic solvents and water. However, if the printing ink is a solventless ink, it may not contain a solvent. Examples of organic solvents include acetate esters, lactate esters, ketones, hydrocarbons, alcohols, and glycol ethers. Specific examples include methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, ethyl lactate, butyl lactate, acetylacetone, acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, cyclohexane, methylcyclohexane, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether. These organic solvents may be used alone or in combination of two or more. Among these, ethyl acetate or butyl acetate is preferred because of its high volatility and excellent drying properties. The content of the solvent in the printing ink when a solvent is included is not particularly limited, but may be, for example, 50% by weight to 90% by weight, more preferably 60% by weight to 85% by weight, and more preferably 70% by weight to 80% by weight. Within this range, the resin components constituting the printing ink can be sufficiently dissolved, and it is possible to prevent the printed layer from falling off from the fibers of the nonwoven fabric, and it is possible to reliably adhere the first flame retardant contained in the printed layer (described below) to the fibers of the nonwoven fabric. Furthermore, the printing ink may contain various additives, such as ultraviolet absorbers, fillers, antioxidants, defoamers, dispersants, light stabilizers, and adhesives, as needed.

[0043] The printing layer D on the filter layer S can be formed by a known method. For example, it can be formed by roller, spray, brush, printing, etc. That is, any known method using a device such as a roll coater, comma coater, die coater, inkjet, reverse coater, silk screen, or gravure coater can be used. That is, in the present invention, the printing layer broadly refers to a layer formed from a material containing a coloring component such as printing ink, and the formation method is not limited, and it is not limited to a layer formed by so-called printing. The printing layer D only needs to be formed on at least a portion of one side of the filter layer S, and does not necessarily have to be formed on the entire surface. However, even if formed on the entire surface, the printing layer D has flame retardancy, so the flame retardancy of the entire filter structure can be maintained. Furthermore, the printing layer D may be formed in a stripe or grid shape, and may be formed with letters, symbols, figures, or designed characters. Incidentally, examples of a mode in which the printed layer D is formed on a part of one surface of the filter layer S include a grid-like printed pattern having a predetermined width of 1 mm to 10 mm and arranged at predetermined intervals of 1 cm to 10 cm on the top, bottom, left, and right sides of one surface of the filter layer S, and used as guide lines to guide cutting positions, folding positions, and usage methods.

[0044] The preferred coating amount (formation amount) of the printing layer D is 0.1 g / m 2 at the portion (one side) of the filter layer S where the printing layer D is to be formed. ２ 10g / m or more ２ or less, more preferably 0.5 g / m ２ 5g / m or more ２ More preferably, it is 1 g / m or less. ２ 3g / m or more ２ With this configuration, the filter structure 81 can have a variety of designs and a printed layer D with good color development, which can impart a higher level of design, thereby further improving the design of the filter structure. Furthermore, within this range, the printed layer D does not hinder the filtration of gas through the filter layer S.

[0045] The adhesive layer N is formed on at least a portion of the other surface of the filter layer S. The adhesive used to form the adhesive layer N is not particularly limited, and examples thereof include two-component adhesives containing a base agent and a curing agent, such as two-component polyurethane adhesives, and hot-melt adhesives, such as acrylic hot-melt adhesives. The adhesive may also contain, as needed, additives such as tackifiers to improve adhesion, UV absorbers, fillers, colorants, antioxidants, antifoaming agents, and light stabilizers, as well as various additives to suppress a decrease in adhesive strength at low temperatures and adhesive residue. The adhesive layer N can be formed on the filter layer S using known methods. For example, the adhesive can be directly applied to the filter layer S, or indirectly applied by first applying the adhesive to a removable release sheet layer, as described below, and then contacting the release sheet layer with the filter layer S to transfer the adhesive to the filter layer S, thereby forming a coating film, and then drying (solidifying) the coating film. The application method for directly or indirectly applying the pressure-sensitive adhesive layer N to the filter layer S is not limited, and can be, for example, by roller, spray, brush, printing, etc. That is, any method using a known device, such as a roll coater method, comma coater method, die coater method, inkjet method, reverse coater method, silk screen method, gravure coater method, etc., can be employed. In the case of direct application, for example, the pressure-sensitive adhesive layer N can be formed on the filter layer S by spraying the pressure-sensitive adhesive onto one side of the filter layer S entirely or partially by spraying. In the case of indirect application, for example, a method can be employed in which the pressure-sensitive adhesive is printed on a silicone-coated, releasable release sheet layer with a roll or the like, and then the pressure-sensitive adhesive layer N side of this release sheet layer is brought into contact with the filter layer S and pressed with a roll or the like, thereby transferring the pressure-sensitive adhesive layer N to the filter layer S. The adhesive layer N may be formed on at least a portion of one side of the filter layer S, similar to the printing layer D. However, in this case, the printing layer D may be oriented toward the surface facing the range hood, etc., which may make the printing layer D difficult to see and prevent it from exhibiting its design properties. Therefore, it is preferable that the adhesive layer N be formed on at least a portion of the other side of the filter layer S.

[0046] The release sheet layer may be, for example, a PET film with a silicone coating formed on at least one side. The release sheet layer protects the surface of the adhesive layer N, preventing it from adhering to objects other than the intended target before use of the filter structure 81. It also improves ease of handling, allowing multiple filter structures 81 to be stacked. Upon use, the release sheet layer is peeled off, and the exposed adhesive layer N is attached to the target like a sticker. In addition to PET film, other materials that can be used for the release sheet layer include cellophane, resin films other than PET, paper with a surface treatment such as a resin coating, and metal sheets. The adhesive layer N may be formed by a spray method as described above, or by pattern printing into a strip or grid shape. It may also be formed with letters, symbols, figures, or character designs. The maximum peel load K of the pressure-sensitive adhesive layer N at 5° C. is preferably set in the range of 0.01 N / mm to 0.05 N / mm, more preferably 0.02 N / mm to 0.04 N / mm. By setting the pressure-sensitive adhesive layer N in this manner, it is possible to reliably prevent the pressure-sensitive adhesive layer N from falling off from the object even under a temperature condition as low as 5° C.

[0047] In the filter structure 81 of this example, the adhesive layer N need only be formed on at least a portion of the other side of the filter layer S; it is not necessarily formed on the entire surface. However, this does not preclude the formation of an adhesive layer N on the entire surface of the filter layer S. An example of forming an adhesive layer N on the entire surface of the filter layer S is by spray-coating the other side of the filter layer S with an amount of adhesive that does not impair the breathability of the filter layer S. Of course, even in the case of spray-coating, it is also possible to form an adhesive layer N only on a portion of the filter layer S. For example, if the filter layer S has a rectangular shape, it is possible to form an adhesive layer N only near the periphery of the rectangular shape, with no adhesive layer N formed on the interior side. Alternatively, the adhesive layer N may be formed partially by pattern coating. For example, if the filter layer S has a rectangular shape, it is possible to form a strip-shaped adhesive layer N only on or near the periphery of the rectangular shape, with no adhesive layer N formed on the interior side. Furthermore, in addition to forming a band-shaped adhesive layer N on or near the periphery of the rectangular shape, it is also possible to form a striped or lattice-shaped adhesive layer N on the inner side. In the case of pattern coating, since the gaps between the fibers in the area where the adhesive is formed are often completely filled with adhesive, it is preferable to adopt an area where the adhesive layer N is formed on at least a part of the other side of the filter layer S. The preferred amount of application (formation amount) of the adhesive layer N is such that the amount of the adhesive layer N formed on the filter layer S at the area where the adhesive layer N is formed on the filter layer S (the other side) is preferably 5 g / m ２ 50g / m or more ２ or less, more preferably 15 g / m ２ 30g / m or more ２ With this configuration, the necessary adhesive strength can be secured when the filter structure 81 is attached to the attachment object, so that the filter structure 81 is prevented from peeling off or falling off, and the filtration of gas by the filter layer S is not hindered.

[0048] In the filter structure 81 of the present invention, the printed layer D contains the first flame retardant in an amount of 2.0% by weight to 45% by weight, and preferably in an amount of 9% by weight to 30% by weight. This configuration imparts flame retardancy to the printed layer D, thereby imparting designability to the filter structure 81 and improving the flame retardancy of the entire filter structure 81.

[0049] In the present invention, the first flame retardant refers to a flame retardant contained in the printing layer, and various types can be used as long as they do not impair the effects of the present invention. Flame retardants can be broadly classified into halogen-based flame retardants containing halogen elements and non-halogen-based flame retardants not containing halogen elements, and either type can be used as the flame retardant used in the present invention. Examples of halogen-based flame retardants containing halogen elements include bromine compounds, chlorine compounds, and halogen-containing phosphorus-based compounds (e.g., halogen-containing phosphate esters). In this case, Sb can be used as the flame retardant aid. ２ O ３ Inorganic compounds such as antimony trioxide, ZnS (zinc sulfide), zinc borate, and zinc stannate can be used in combination. The content of the flame retardant aid is calculated as the content of the flame retardant.

[0050] Non-halogen flame retardants that do not contain halogen elements can be inorganic or organic. For example, inorganic non-halogen flame retardants include hydrated metal compounds such as aluminum hydroxide, magnesium hydroxide, and calcium aluminate, phosphorus compounds such as red phosphorus, nitrogen compounds such as ammonium phosphate and ammonium carbonate, molybdenum compounds, zinc borate, and zinc stannate. Some of these inorganic compounds act as auxiliary flame retardants for halogen flame retardants when used in combination with halogen flame retardants.

[0051] On the other hand, examples of organic non-halogen flame retardants include halogen-free phosphorus-based compounds such as phosphate esters, phosphorus-containing polyols, and phosphorus-containing amines; silicone compounds such as silicone polymer powders; and halogen-free nitrogen-based compounds such as triazine compounds, melamine cyanurate, and guanidine compounds.

[0052] Among these, in the present invention, non-halogen flame retardants that are less likely to generate toxic gases upon thermal decomposition are preferred, and among these, organic non-halogen flame retardants are preferred, and among these, phosphate esters are more preferred because the gases generated upon combustion are safer for humans.

[0053] In the present invention, it is preferable that one surface of the filter layer S, which corresponds to the surface of the area where the printed layer D is formed on the filter layer S, has a flammability test result of JIS L 1091 A-1 method (45° microburner method) of category 3. This configuration improves the flame retardancy of the entire filter structure.

[0054] In the filter structure 81 of the present invention, the pressure-sensitive adhesive layer N contains 3 wt % or more of the second flame retardant. By configuring in this manner, the pressure-sensitive adhesive layer N is also imparted with flame retardancy, thereby improving the flame retardancy of the entire filter structure 81.

[0055] In the present invention, the second flame retardant refers to a flame retardant contained in the adhesive layer, and various types can be used as long as they do not impair the effects of the present invention. Flame retardants can be broadly classified into halogen-based flame retardants containing halogen elements and non-halogen-based flame retardants not containing halogen elements, and either type can be used as the flame retardant used in the present invention. Examples of halogen-based flame retardants containing halogen elements include bromine compounds, chlorine compounds, and halogen-containing phosphorus-based compounds (e.g., halogen-containing phosphate esters). In this case, Sb can be used as the flame retardant aid. ２ O ３ Inorganic compounds such as antimony trioxide, ZnS (zinc sulfide), zinc borate, and zinc stannate can be used in combination. The content of the flame retardant aid is calculated as the content of the flame retardant.

[0056] Non-halogen flame retardants that do not contain halogen elements can be inorganic or organic. For example, inorganic non-halogen flame retardants include hydrated metal compounds such as aluminum hydroxide, magnesium hydroxide, and calcium aluminate, phosphorus compounds such as red phosphorus, nitrogen compounds such as ammonium phosphate and ammonium carbonate, molybdenum compounds, zinc borate, and zinc stannate. Some of these inorganic compounds act as auxiliary flame retardants for halogen flame retardants when used in combination with halogen flame retardants.

[0057] On the other hand, examples of organic non-halogen flame retardants include halogen-free phosphorus-based compounds such as phosphate esters, phosphorus-containing polyols, and phosphorus-containing amines; silicone compounds such as silicone polymer powders; and halogen-free nitrogen-based compounds such as triazine compounds, melamine cyanurate, and guanidine compounds.

[0058] Among these, in the present invention, non-halogen flame retardants that are less likely to generate toxic gases upon thermal decomposition are preferred, and among these, organic non-halogen flame retardants are preferred, and among these, phosphate esters are more preferred because the gases generated upon combustion are safer for humans. Note that the first flame retardant and the second flame retardant may be the same flame retardant or different flame retardants. Appropriate flame retardants may be selected depending on the components of the printing layer D and the pressure-sensitive adhesive layer N.

[0059] In the present invention, the second flame retardant is preferably contained in the adhesive layer N in a range of 10% by weight to 30% by weight. This can further improve the flame retardancy of the entire filter structure 81, and can ensure the necessary adhesive strength when the filter structure 81 is attached to an object to which it is attached, thereby preventing the filter structure 81 from peeling or falling off. Incidentally, when the content of the second flame retardant in the adhesive layer N is 30% by weight or less, a decrease in the adhesive strength of the filter structure 81 due to a decrease in the amount of adhesive in the adhesive layer N is prevented, thereby reducing the risk of the filter structure 81 peeling or falling off from the object to which it is attached. This is particularly preferable when used in a range hood, because it can prevent the filter structure 81 from peeling or falling off during cooking, thereby reducing the risk of a fire from a gas stove spreading to the filter structure 81.

[0060] In the present invention, it is preferable that one surface of the filter layer S, which corresponds to the back surface of the area where the pressure-sensitive adhesive layer N is formed on the filter layer S, has a flammability test result of JIS L 1091 A-1 method (45° microburner method) of category 3. This configuration improves the flame retardancy of the entire filter structure.

[0061] The filter structure 81 of the present invention can be widely used as an air filter product in ventilation parts of industrial equipment, as well as in household appliances such as kitchen and range hoods, air conditioners, and ventilation fans, and in vents installed indoors and outdoors. Among these, the filter structure 81 is particularly suitable for use in range hoods because of its high flame retardancy.

[0062] The filter structure 81 of the present invention can be applied to an object whose surface is plated with an aluminum-zinc alloy or coated with a polyester coating. In particular, many commonly used range hoods are made of steel plates coated with various types of plating or polyester coating, but by applying the filter structure 81 of the present invention to an object whose surface is plated or coated as described above, it is possible to further reduce the occurrence of adhesive residue when the filter structure 81 is removed.

[0063] Furthermore, the adhesive layer N may be used to display letters, marks, patterns, etc. indicating when it is time to replace the filter. The filter layer S becomes colored by capturing oily smoke and dust in the air in areas other than the letters, etc. As a result, colorless letters, etc. that were barely legible before use, become clearly readable as the surrounding area becomes colored over time, and the letters, etc. become outlined characters. Therefore, by displaying the content indicated by letters, etc., when it is time to replace the filter, it is possible to notify the user.

[0064] Furthermore, the filter structure 81 of the present invention can be used for relatively large products in which at least one of the filter layers S has a length of, for example, 25 cm or more. This is because the larger the filter structure 81, such as when at least one of the filter layers S has a length of 30 cm or more, or even 35 cm or more, the more likely it is to fall off or partially peel off from the object due to its own weight. In particular, when used in a range hood, the size of the filter structure 81 used varies depending on the model, but it is common for at least one of the filter structures 81 to be large, measuring several tens of centimeters or more. Therefore, if the present invention is applied to such a large filter structure 81, it will not fall off from the object even when attached to the object at a low temperature of 5°C.

[0065] It has been demonstrated through tests that the filter structure of the present invention has the effect of improving flame retardancy.

[0066] The sample was prepared for use as a metal filter in a range hood, and used a filter structure in which a printed layer was formed by gravure printing on one side of each filter layer made of nonwoven fabric with the basis weight and breathability described below, and an adhesive layer was formed on the other side by a different method.

[0067] A nonwoven fabric made from fibers made from PET (polyethylene terephthalate) was used as the filter layer. The PET-based fibers contained 40% by weight of flame-retardant PET fibers. The filter layers (filter layers before the PSA layer was formed) were tested in accordance with 1) the JIS L 1091 A-1 method (45° microburner method) described below, resulting in category 3 for all filter layers. The test results for 2) the vertical flame test (afterflame time and presence or absence of dripping) were also good for all filter layers, with the afterflame time and presence or absence of dripping both being good.

[0068] For the printed layer, in Examples 1 to 7-2 and Comparative Examples 1 to 6, a black base paint containing, as main components, a coloring material component (carbon black), a resin component (acrylic resin), and a solvent for dissolving the resin component was prepared. In Example 8, a gray base paint containing, as main components, a coloring material component (carbon black and titanium oxide), a resin component (acrylic resin), and a solvent for dissolving the resin component was prepared. A phosphorus-based flame retardant was mixed as a first flame retardant in the base paint in the blending amounts shown in Table 2 to prepare a printing ink. After drying, the coating amount was about 2 g / m. ２ In Examples 1 to 6 and 8 and Comparative Examples 1 to 5, a printed layer was formed on the filter layer by coating and drying the entire surface of one side of the filter layer, and in Examples 7-1, 7-2 and Comparative Example 6, a printed layer was formed on the filter layer by coating and drying the printed layer on a portion of one side of the filter layer as a guide line in the manner described below. However, a filter layer without a printed layer was also prepared as Comparative Example 0. In Examples 7-1, 7-2 and Comparative Example 6, the printed layer formed as a guide line on one side of the filter layer was formed in a grid-like printing pattern with a width of approximately 2 mm, arranged at 5 cm intervals above, below, left and right of the filter layer.

[0069] As the adhesive layer, a hot-melt adhesive was prepared to fabricate the filter structure samples. In the examples and comparative examples, an acrylic hot-melt adhesive was used as the hot-melt adhesive.

[0070] The pressure-sensitive adhesive layer was formed by pattern coating (a method in which the pressure-sensitive adhesive is applied to a release sheet in a desired pattern design, and then the release sheet layer is brought into contact with the filter layer to transfer the pressure-sensitive adhesive to the filter layer, thereby forming a strip-shaped pressure-sensitive adhesive pattern on the surface of the filter layer) and spray coating (a method in which the pressure-sensitive adhesive is sprayed onto one side of the filter layer, either entirely or partially, to form a pressure-sensitive adhesive layer on the filter layer). In the pattern coating, the pressure-sensitive adhesive layer was formed with a 1 cm-wide strip-shaped pressure-sensitive adhesive pattern that went all the way around the periphery of the filter layer, and a 1 cm-wide grid-shaped pressure-sensitive adhesive pattern that was spaced 5 cm apart from one another.

[0071] The range hood used in the test was a model "BDR-3HL-601BK" manufactured by Fuji Industrial Co., Ltd.

[0072] The tests were conducted on six types of materials: 1) JIS L 1091 A-1 method (45° microburner method), 2) vertical combustion test (afterflame time and presence or absence of dripping), 3) friction fastness test (JIS L 0849 Type II (Gakushin type method)), 4) bleeding condition on the printed layer surface, 5) adhesion strength 1 of the filter structure to the metal filter (maximum peel load at 5°C), and 6) adhesion strength 2 of the filter structure to the metal filter (observation of the condition after attachment of the filter structure to the metal filter). 1) JIS L 1091 A-1 method (45° microburner method) This method measures the extent of combustion spread (burning area and burning length), afterflame, and afterglow time. Based on these measurements, the samples were evaluated as falling into category 1, 2, or 3 according to the flammability classifications specified in the A-1 method after one minute of heating and three seconds after ignition. 2) Vertical Flame Test (Afterflame Time and Presence or Absence of Drip) For each filter structure of the Examples and Comparative Examples, a strip measuring 5 cm x 15 cm was cut out, and the test strip was held vertically with the tip of a flame applied to the bottom 5 cm. The flame was applied to the area where the adhesive layer was formed. Evaluation was performed based on the evaluation criteria in Table 1 below.

[0073] 3) Rubbing Fastness Test (JIS L 0849 Type II (Gakushin-type method) Drying Test) For each filter structure of the Examples and Comparative Examples, the surface of the filter layer on which the printed layer was formed was evaluated for fastness using the test method of the JIS standard. Grade 4 or higher in the drying test was evaluated as "Good", Grade 3 as "Good", and Grade 2 or lower as "Poor". 4) Bleeding State on the Printed Layer Surface For each filter structure of the Examples and Comparative Examples, a 12 μm thick PET (polyethylene terephthalate) film was placed on the surface of the printed layer of the filter layer, and the filter structure was left to stand in a constant temperature and humidity chamber at 40°C and 75% humidity for two weeks, after which the state of bleeding of the first flame retardant onto the surface of the printed layer was visually observed. The evaluation was "Good" if there was no adhesion that appeared to have been caused by bleeding from the printed layer on the PET film surface, "Good" if there was a small amount of adhesion that appeared to have been caused by bleeding from the printed layer on the PET film surface, and "Poor" if there was extensive adhesion of adhesion that appeared to have been caused by bleeding from the printed layer on the PET film surface. 5) Adhesion strength 1 of filter structure to metal filter (maximum peel load at 5°C) The basic measurement method for "maximum peel load" was in accordance with "JIS Z 0237:2009," but the measurement conditions were as described below. The test was also conducted with a temperature environment set to 5°C. For "maximum peel load," the maximum load when peeling a sample from an object after it had been attached to the object was measured. A constant-speed extension tester was used as the testing machine, and filter structures measuring 5 mm wide x 250 mm long and 10 mm wide x 250 mm long (with similar dimensions for the adhesive layer) were prepared as samples. A SUS304 stainless steel plate was used as the surface to be attached. The test was conducted by attaching the sample to the above-mentioned object, rolling a 1 kg roller back and forth across the surface twice, and then peeling in a 180-degree direction at a peel rate of 100 mm / min, and measuring the maximum load. If the maximum peel load at this time was 0.02 N / mm or more, it was evaluated as "Good", if it was 0.01 N / mm or more but less than 0.02 N / mm ...Poor", and if it was less than 0.01 N / mm, it was evaluated as "Poor". 6) Adhesion strength of filter structure to metal filter 2 (observation of condition after filter structure is attached to metal filter) The metal filter is removed from the range hood and placed on a horizontal stand.A filter structure of the same dimensions as the metal filter was prepared, and this filter structure was attached so that the side on which the adhesive layer was formed was attached to the surface of the metal filter. Note that, during attachment, the filter structure of the predetermined dimensions was placed on the surface of the metal filter, and the side of the filter structure on which the adhesive layer was not formed was pressed with a roller at a pressure of 2 kg / cm. ２ The filter structure was pressed against the metal filter by one reciprocating motion. After that, after 10 minutes had elapsed, the metal filter was raised to a vertical position, and the presence or absence of the filter structure falling off from the metal filter was evaluated by visual observation. That is, the case where no falling off of the filter structure from the metal filter was observed was evaluated as "○", the case where peeling of even a part of the filter structure from the metal filter was observed but the filter structure did not fall off was evaluated as "△", and the case where the filter structure fell off from the metal filter was evaluated as "×". The test was carried out in a temperature environment set at 5°C.

[0074] The test results of 1) to 6) are shown in Tables 2 and 3 below.

[0075]

[0076]

[0077] As described above, the filter structure according to the present invention is suitable as a filter structure that is attached to an object such as a range hood, an air conditioner, an air purifier, or a vent, for filtering gas passing through.

Claims

1. A filter structure (81) for attaching to an object (74) to filter gas passing therethrough, comprising: a filter layer made of a breathable sheet-like member; and a printed layer formed on at least a portion of one side of the filter layer, the printed layer containing 2.0% by weight or more and 45% by weight or less of a first flame retardant.

2. The filter structure according to claim 1, wherein said printed layer contains said first flame retardant in an amount of 9% by weight or more and 30% by weight or less.

3. At a portion where the printed layer is formed on the filter layer, the printed layer has a thickness of 0.1 g / m ２ 10g / m or more ２ 3. A filter structure according to claim 1 or claim 2, which is formed in the following range:

4. A filter structure as described in claim 1 or claim 2, further comprising an adhesive layer formed on at least a portion of the other surface of the filter layer for adhering to the object, the adhesive layer containing 3% by weight or more of a second flame retardant.

5. The filter structure according to claim 4, wherein said adhesive layer contains 10% by weight or more and 30% by weight or less of said second flame retardant.

6. At a portion where the pressure-sensitive adhesive layer is to be formed on the filter layer, the pressure-sensitive adhesive layer is 5 g / m2 with respect to the filter layer. ２ 50g / m or more ２ 5. The filter structure of claim 4 formed from:

7. The filter structure according to claim 4, wherein both of said first flame retardant and said second flame retardant are organic non-halogen flame retardants.

8. A filter structure according to claim 1 or 2, wherein one side of the filter layer, which corresponds to the surface of the area on which the printed layer is formed, is classified as 3 in a flammability test according to JIS L 1091 A-1 method (45° microburner method).

9. The filter structure according to claim 1 or 2, wherein the object is a range hood.