Filter structure

Abstract

To provide a filter structure capable of: making exfoliation of a release sheet easy even when the release sheet is thin; making the filter structure never dropped off from a ventilation device; and preventing deterioration of the aeration capability of the ventilation device.SOLUTION: A filter structure 10 has a rectangular shape in a plan view, and includes a filter main body 11, an adhesive layer 12, and a release sheet 13. The filter main body is formed with pinch portions 11a at four corners thereof, with no adhesive layer formed on the pinch portions. Width of the pinch portion is defined by a distance A from an outer edge of the filter main body to an outer edge of the adhesive layer, and the distance A is 9 to 35 mm inclusive. The release sheet can be easily released from the filter main body by pinching the pinch portion even when the release sheet is thin. Since the pinch portion is not so big that, when the filter structure is stuck to a ventilation device, exfoliation starts at the pinch portion, the filter structure can be prevented from dropping off.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a filter structure that is attached to a ventilation device and filters gas passing through it. [Background technology]

[0002] As disclosed in Patent Documents 1 to 3, filter structures are known that are attached to ventilation devices (such as range hoods, ventilation fans, vents, electric fans, circulators, air purifiers, and air conditioners, the same applies below) to filter the air passing through and prevent the ventilation device from becoming dirty.

[0003] This type of filter structure has a configuration in which an adhesive layer made of an adhesive is formed on one side of a sheet-like filter body made of nonwoven fabric or the like. Furthermore, a thin release sheet is usually attached to the surface of the adhesive layer to prevent the adhesive layer from unintentionally sticking to items other than the ventilation device when the filter structure is not in use. To attach such a filter structure to an object such as a range hood or an air conditioner, the release sheet is removed to expose the adhesive layer, which is then aligned to the attachment location and then pressed against the surface.

[0004] In this type of filter structure, the filter body made of nonwoven fabric or the like, the adhesive layer formed on the filter, and the release sheet laminated on the adhesive layer all generally have a small thickness. An adhesive layer is formed right up to the outer edge of the filter body to prevent it from lifting up from the point where it is attached to the ventilation device, and the release sheet is laminated so that its outer edge roughly coincides with the outer edge of the filter body. Therefore, when using the filter structure, the three layers of filter body, adhesive layer, and release sheet, which are thin and overlap with their outer edges almost aligned, must be peeled up by hooking a fingernail only on the release sheet, which is not an easy task.

[0005] In this regard, a common method for manufacturing a filter structure involves first forming an adhesive layer on one side of a roll-shaped release sheet, and then laminating the side of the release sheet with the adhesive layer formed thereon to one side of a roll-shaped filter body, thereby transferring the adhesive layer to the filter body. At this time, assuming that the laminated filter structure will be cut to the desired dimensions with a slit, attempts have been made to not form an adhesive layer in a small area of ​​about 5 mm up to the outer edge of the filter body so that the adhesive does not adhere to the slit blade, in other words, to form a gusset portion as a non-adhesive layer along the outer edge of the filter body.

[0006] This configuration may seem to make it easier to roll up the release sheet from the gusset portion, but in reality, there are many cases where the distance from the outer edge of the adhesive layer to the outer edge of the filter structure is extremely close due to dimensional variations during cutting. In such cases, since there is almost no gusset, it is difficult to find the peeling line, and it is difficult to catch your fingernails or fingers on it, so the task of peeling up just the release sheet remains difficult. In addition, for example, when the ventilation device is a ventilation opening (exhaust fan) installed on the ceiling of a toilet or changing room, if one were to imagine peeling off the filter structure from the ventilation opening after use, it would be difficult to do so because the width of the gusset portion where the adhesive layer is not formed is narrow and the work would require working at a high place. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2002-85927 A [Patent Document 2] JP 2017-15297 A [Patent Document 3] JP 2021-146274 A Summary of the Invention [Problem to be solved by the invention]

[0008] On the other hand, if the thickness of the release sheet is increased, it will be more likely to be caught by fingers and peeled off from the filter structure, but the rigidity of the release sheet itself will increase. As a result, the adhesive layer has poor conformability to the filter body on which it is formed during production, and there is a risk that the release sheet will partially peel off from the adhesive layer of the filter body during the winding process of the filter structure before cutting or during the folding operation in the packaging process of the filter structure. Furthermore, compared to a case where the release sheet is thinner, the material costs are higher, making it difficult to provide a filter structure as a product at low cost.

[0009] Furthermore, if the area from the outer edge of the filter body where the adhesive layer is not formed, i.e., the gusset portion, is made larger, the release sheet will be easier to roll up, but the adhesive layer will be biased overall toward the center of the filter, meaning that the adhesive layer will be positioned over a wide area at the main ventilation points, which may reduce the ventilation capacity of the ventilation device. Similarly, if the range of the gusset portion is increased, when the ventilation device is a ventilation opening (exhaust fan) installed in the ceiling of a toilet or changing room, the frame of the ventilation opening is often not flat but has rounded edges, which reduces the ability to conform to the ventilation opening and may cause it to fall off from the non-adhesive layer.

[0010] Therefore, the problem to be solved by the present invention is to make it easy to peel off a release sheet in a filter structure even when the release sheet is thin, to prevent it from falling off from the ventilation device, and to prevent a decrease in the ventilation capacity of the ventilation device. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems, the filter structure of the invention is polygonal in a plan view and comprises at least a filter body, an adhesive layer made of an adhesive partially formed on one side of the filter body, and a release sheet laminated on top of the adhesive layer, and a gripping portion is formed on part of the outer edge of the filter body where the adhesive layer is not formed, and the width of the gripping portion is defined by the distance A from the outer edge of the filter body to the outer edge of the adhesive layer located more inward, and the distance A is 9 mm or more and 35 mm or less. In addition, the filter structure of the invention is circular in a plan view and comprises at least a filter body, an adhesive layer made of an adhesive partially formed on one side of the filter body, and a release sheet laminated on top of the adhesive layer, and a gripping portion is formed on a part of the outer edge of the filter body where the adhesive layer is not formed, and the width of the gripping portion is defined by the distance A from the outer edge of the filter body to the outer edge of the adhesive layer located more inward, and the distance A is 5 mm or more and 35 mm or less.

[0012] With this configuration, by pinching the knob of an appropriate size, the release sheet can be easily peeled off from the filter body even when the release sheet is thin. Similarly, when removing the filter structure from a ventilation device or the like that is located at a high place, the work becomes easier by using the gripping portion as a starting point.

[0013] Furthermore, when configured in this manner, the width of the knob is large enough to easily pinch, but not so large that when the filter structure is attached to an intake and exhaust ventilation device, this is the starting point from which the filter body will peel off over time. This also prevents the filter structure from falling off the ventilation device.

[0014] Furthermore, with this configuration, the tab portion is small in size, and therefore the presence of the tab portion does not cause the adhesive layer to be significantly biased toward the center of the filter structure. Therefore, it is possible to prevent a situation in which the adhesive layer becomes a hindrance and adversely affects the ventilation performance of the ventilation device.

[0015] By setting the distance A of the knob portion within the above range, such an effect can be achieved. If the distance A of the tab is more than 35 mm, the dimensions of the tab become too large, and when the filter structure is attached to a ventilation device with a rounded outer edge, the tab may peel off over time, causing the filter structure to fall off. In addition, the tab may cause the filter structure to bend or wrinkle during packaging, causing the release sheet to peel off from the adhesive layer before use. In addition, the effective ventilation area of ​​the filter body may be reduced. The effective ventilation area of ​​the filter body means the area of ​​the part that effectively functions to capture dust, oil stains, etc., relative to the total area of ​​the filter body in a plan view when the filter body is attached to a ventilation device. If the total area of ​​the filter body in a plan view is the same, the effective ventilation area of ​​the filter body will decrease as the distance A of the tab or the distance B of the gusset portion described later increases. When the filter structure is circular in a planar view and the distance A of the gripping portion is less than 5 mm, and when the filter structure is polygonal in a planar view and the distance A of the gripping portion is less than 9 mm, the dimensions of the gripping portion will be too small, making it difficult to grip and to peel off the release sheet.

[0016] In the filter structure of the invention, a gusset portion where the adhesive layer is not formed is formed along the outer edge of the filter body at a position different from the tab portion, and the width of the gusset portion is defined by the distance B from the outer edge of the filter body to the outer edge of the adhesive layer located further inward, and it is preferable to adopt a configuration in which distance B<distance A holds.

[0017] With this configuration, when the filter structure is cut to the desired dimensions by slitting during the general manufacturing process of the filter structure, the adhesive does not adhere to the slit blade, so there is no effect on productivity. In addition, since the gusset portion is narrower than the tab portion, there is no risk of the filter structure peeling off or falling off from the ventilation device at this point.

[0018] In the filter structure of the present invention, it is preferable to adopt a configuration in which the distance A of the tab portion is 9 mm or more and 30 mm or less, and the distance B of the gusset portion is 1 mm or more and 8 mm or less.

[0019] By configuring the distance B of the gusset portion in this manner, even if there is a reasonable variation in the dimensions of the filter structure, the adhesive of the adhesive layer is further prevented from adhering to the slit blade during the cutting process. In addition, the filter structure is further prevented from peeling off or falling off from the ventilation device starting from the gusset portion. If the distance B is less than 1 mm, the width of the gusset portion will be too small, and depending on the variation in the dimensions of the filter structure, the adhesive may adhere to the slit blade, making it difficult for the blade to cut the filter structure properly, which may affect the productivity of the filter structure. If the distance B is more than 9 mm, when the filter body is attached to the ventilation device, the outer edge of the filter body may rise up from the ventilation device, which may encourage the filter body to fall off. Also, the effective ventilation area of ​​the filter body may be reduced. A more preferable range for the distance A is 10 mm or more and 28 mm or less, and a more preferable range for the distance B is 2 mm or more and 8 mm or less.

[0020] In the filter structure of the invention, the filter body can be polygonal in a planar view, the distance A being the length of a line segment that bisects each vertex angle of the filter body, with one end being the outer edge of the filter body and the other end being the outer edge of the adhesive layer, and the distance B being the shortest distance from each side of the filter body to the outer edge of the adhesive layer.

[0021] In this way, the gripping portions are positioned radially from the corners of the polygon, making it easy to grip and peel off the release sheet, and since the gusset portions are located on at least a portion of each side of the polygon, adhesion of the adhesive to the slit blades during manufacturing and cutting is effectively prevented.

[0022] In the filter structure according to the present invention, it is preferable that the filter body is rectangular, and the knobs are formed at the four corners of the rectangular filter body.

[0023] In this way, by arranging the gripping portions at the four corners of the rectangular filter body, the release sheet can be easily peeled off with a simple structure.

[0024] In the filter structure according to the present invention, it is preferable to adopt a configuration in which the gusset portions are formed along each of the four sides of a rectangular filter body.

[0025] In this way, by arranging the gusset portions on the four sides of the rectangular filter body, it is possible with a simple configuration to easily prevent the adhesive from adhering to the slit blades during production.

[0026] In the filter structure of the present invention, it is preferable that the filter body has a thickness of 0.2 mm or more and 10 mm or less, and the release sheet has a thickness of 1 μm or more and 50 μm or less.

[0027] In this way, the release sheet can exhibit good releasability at low cost. If the thickness of the filter body is less than 0.2 mm, it may be too thin and may not be able to capture enough dirt in the air, and if the thickness of the filter body is more than 10 mm, the basis weight may become too large, increasing the material cost and causing the filter to peel off from the ventilation device due to its own weight. If the thickness of the release sheet is less than 1 μm, it may be too thin and difficult to catch the finger on the grip, making it difficult to peel off the release sheet. If the thickness of the release sheet is more than 50 μm, the material cost increases, and the rigidity becomes too large, making it difficult to conform to the filter body, and there is a risk that the release sheet will peel off from the filter body when the filter structure is wound up or folded during packaging. Therefore, it is preferable that the release sheet has a desired rigidity that is less likely to cause these problems.

[0028] In the filter structure according to the present invention, the adhesive layer may have a replacement time indicator for indicating the time to replace the filter structure based on a dirt pattern on the filter body.

[0029] The parts of the filter body where the adhesive layer is laminated are almost unable to breathe and do not attract much dirt, but the parts where the adhesive layer is not laminated have good breathability and attract a lot of dirt. Depending on the pattern of the adhesive layer, the dirty and unsoiled parts of the filter body appear as a contrast, and if a picture or the like is made to stand out, it becomes visually easy to see when it is time to replace the filter structure. By providing such a replacement time indicator on the adhesive layer, the convenience of the filter structure is improved. Effect of the Invention

[0030] Since the filter structure of the invention is configured as described above, it is possible to easily peel off the release sheet even when the release sheet is thin, prevent it from falling off from the ventilation device, and prevent a decrease in the ventilation capacity of the ventilation device. [Brief description of the drawings]

[0031] [Figure 1] Plan view of the filter structure [Diagram 2] Side view of the filter structure [Diagram 3] Enlarged plan view of the filter structure [Figure 4] FIG. 1 is a plan view showing another example of a filter structure; [Diagram 5] FIG. 1 is a plan view showing another example of a filter structure; [Figure 6] FIG. 1 is a plan view showing another example of a filter structure; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The filter structure 10 shown in Figs. 1 to 3 is attached to an intake ventilator to filter the air passing through it and to prevent the intake ventilator from becoming dirty.

[0033] As shown in Fig. 1, the filter structure 10 is rectangular in plan view so as to match the rectangular opening of the ventilation device, and as shown in Fig. 2, has at least three layers: a filter body 11, an adhesive layer 12, and a release sheet 13. In addition to these three layers, the filter structure 10 may have other layers such as an antibacterial layer. When mounting the device on the ventilation system, the release sheet 13 is peeled off to expose the adhesive layer 12, which is then pressed against the opening and attached. The length and width of the filter structure 10 are not particularly limited, but examples of sizes that match the length and width of typical openings in ventilation devices include relatively small ventilation devices such as ventilation openings installed in the ceilings of washrooms and toilets, indoor ventilation openings compatible with 24-hour ventilation systems, and outdoor ventilation openings installed on the walls of outdoor buildings, and both the length and width are within the ranges of 100 mm to 300 mm, while relatively large ventilation devices such as range hoods, air conditioners, air purifiers, and bathroom dryers installed in kitchens. The filter structure 10 may also be in the form of a long roll.

[0034] The filter body 11 is made of a sheet capable of capturing dust, oily stains, etc., and examples thereof include nonwoven fabric, woven fabric, and knitted fabric. However, nonwoven fabric is preferred as it has good dust, oily stain, etc. capturing performance and is relatively low cost. The material of the nonwoven fabric is not particularly limited, and examples thereof include known synthetic fibers and natural fibers such as polyester fibers such as polyethylene terephthalate, polyolefin fibers such as polyethylene and polypropylene, polyamide fibers, acrylic fibers, etc. Furthermore, the nonwoven fabric may be appropriately subjected to flame retardant, antibacterial, or antifungal treatment within a range that does not impair the effects of the present invention. When using the filter structure 10, the release sheet 13 is peeled off from the filter structure 10 to expose the adhesive layer 12, and the filter body 11 is attached so as to be sealed by facing the opening of the ventilation device and holding it down with a hand, etc. The filter body 11 attached to the ventilation device in this way filters out dust, oily dirt, etc. contained in the gas passing through it, and prevents dirt from adhering to the ventilation device. The thickness of the filter body 11 is not particularly limited, but is preferably 0.2 mm or more and 10 mm or less. When the filter body 11 is a nonwoven fabric, the basis weight is preferably 20 g / m 2 More than 200g / m 2 It is preferable that: Weight is 20g / m 2 If the weight is less than 200g / m, the fabric will be weak and prone to breakage during the manufacturing process, and will not be able to adequately capture dust, oil, etc. 2 If the thickness exceeds this value, the breathability may be reduced, which may adversely affect the ventilation performance of the ventilation device. In addition, the material cost may increase, and there is a risk that the material may peel off from the ventilation device due to its own weight. The filter body 11 is rectangular, and its outer edge constitutes the outer edge of the filter structure 10 . The color of the filter body 11 is not particularly limited, but it is preferably white so that the degree of dirt adhesion can be easily seen.

[0035] The adhesive layer 12 is formed on at least one surface of the filter body 11 as shown in FIG. 2, in a predetermined pattern as shown in FIG. The adhesive layer 12 is made of an adhesive and can be attached to the ventilation device. The type of adhesive is not particularly limited, but examples that can be used include two-component mixture adhesives containing a base agent and a curing agent, such as two-component mixture polyurethane adhesives, and hot melt adhesives, such as acrylic hot melt adhesives. The method for forming the adhesive layer 12 is not particularly limited, but examples include coating the filter body 11 and the release sheet 13 with an adhesive by a coating method such as screen printing, roll coating, spray coating, inkjet, etc. When the filter body 11 is laminated on top of the adhesive applied to the release sheet 13, the adhesive layer 12 is transferred to the filter body 11. The ratio of the area where the adhesive layer 12 is formed to the entire surface of the filter body 11, that is, the application rate of the adhesive, is not particularly limited, but is preferably 5% to 95%. If the application rate is less than 5%, the area of ​​adhesive layer 12 may be too small to provide sufficient adhesive performance for the ventilation device, and if the application rate exceeds 95%, almost the entire surface of filter body 11 may be covered with adhesive layer 12, making it difficult to ensure breathability. However, in cases where an amount of adhesive sufficient to ensure breathability of filter body 11 is formed on almost the entire surface of the filter body, such as by spray coating (for example, when the adhesive is attached to the entire surface of filter body 11 as adhesive layer 12 in a scattered manner in fine granules, or when the adhesive is applied thinly and adhesive layer 12 includes breathable portions), the application rate of the adhesive is not limited to this.

[0036] The release sheet 13 is laminated on the adhesive layer 12 as shown in FIG. 2 in order to prevent the adhesive layer 12 from unintentionally sticking to an article when the filter structure 10 is not in use. The release sheet 13 has a rectangular shape with approximately the same diameter and dimensions as the filter body 11 . The material of the release sheet 13 is not particularly limited, and examples include paper and resin film, but it is preferably made of resin film as it has good releasability from the adhesive layer 12. The thickness of the release sheet 13 is not particularly limited, but is preferably 1 μm or more and 50 μm or less. If the thickness of the release sheet is less than 1 μm, it may be too thin and difficult to peel off, and if the thickness of the release sheet exceeds 50 μm, the material costs will increase and the rigidity will be too great, which may lead to unintentional peeling off when the filter structure 10 is rolled up or folded during packaging. The bending hardness of the release sheet 13 is not particularly limited, but is preferably 0.0010 gf cm 2 / cm or more 0.200gf·cm 2 / cm or less is preferable. The bending stiffness of the release sheet is 0.200gf cm 2 If the bending stiffness exceeds 0.0010 gf·cm, there is a risk that the release sheet 13 may partially peel off from the adhesive layer 12 of the filter body 11 during the filter winding process during production or during the folding operation in the packaging process of the filter structure 10. 2 If the thickness is less than 1 / cm, the release sheet 13 will have too little stiffness, making it difficult to peel off the release sheet 13 from the filter structure 10. In addition, the meandering of the release sheet 13 during the process of forming the adhesive layer 12 on the filter body 11 may cause left-right misalignment of the adhesive pattern, resulting in defects in the adhesive processing, such as failure to achieve the expected function or design. The bending hardness was measured by cutting the release sheet into a 10 cm square specimen and testing it with a pure bending tester (model number: KES-FB2-A) manufactured by Kato Tech Co., Ltd., with a clamp distance of 1 cm and a bending deformation speed of 0.5 cm. -1 / sec, sensitivity 20gf cm, maximum curvature 2.5cm -1 The bending hardness is measured by preparing a test piece for each measurement, and the larger of the measured values ​​in the longitudinal and transverse directions of the test piece is adopted as the measured value of the bending hardness of the release sheet.

[0037] As shown in FIG. 1, the adhesive layer 12 is made up of a substantially rectangular (rectangular) adhesive main layer 12a and a heart-shaped replacement time indicator 12b disposed inside the adhesive main layer 12a. The replacement time indicator portion 12b also contributes to attaching the adhesive layer 12 to the ventilation device, but if the breathability of the filter body 11 is lost in the area where this is formed, a difference will arise in the dirt capture ability of the filter body 11 compared to other areas. As a result, while dirt accumulates around replacement time indicator 12b of filter body 11 and turns black over time, replacement time indicator 12b does not accumulate dirt because it is not breathable, and as a result, the part of filter body 11 where replacement time indicator 12b is formed remains almost the same color as the background of filter body 11. Therefore, if filter body 11 is white, this part will remain white. As a result, the heart shape of the replacement time indicator 12b will soon become clearly visible due to the color contrast. Therefore, the replacement time indicator 12b functions as a guide for when to replace the filter structure 10. The shape of the replacement time display section 12b is not limited to a heart shape, and may be a character pattern, letters, or the like.

[0038] As shown in FIG. 1, the adhesive main layer 12a is formed in a square ring shape so as to follow the outer edge of the rectangle of the filter body 11 and to be spaced a small distance from the outer edge of the rectangle. The width of the ring of the main adhesive layer 12a is not particularly limited, but is preferably 5 mm or more and 20 mm or less. If the width is less than 5 mm, there is a risk that the adhesive strength to the ventilation device will be insufficient, and if the width exceeds 20 mm, the effective ventilation area of ​​the filter body 11 will be small, and the performance of capturing dust, oil stains, etc. will be reduced.

[0039] The adhesive layer 12a has four outer corners that are cut out at an angle corresponding to the four right-angled corners of the filter body 11. The adhesive layer 12a also has four inner corners that are angled. The areas where no adhesive layer is formed, from the four corners of the outer edge of the filter body 11 to the four corners of the outer edge of the main adhesive layer 12a, are tab-shaped gripping portions 11a. When using the filter structure 10, the release sheet 13 can be easily peeled off by pinching the tab 11a. Although the provision of the tabs 11a may reduce the adhesive strength at the four corners, the inside of the rectangular adhesive layer 12a is also angled or curved rather than at a right angle, preventing a shortage of adhesive area (or adhesive strength) at the corners. As long as the effective ventilation area of ​​the filter body 11 is not reduced excessively, the adhesive strength can be ensured by making the inside of the ring angled or curved.

[0040] As shown in FIG. 1, the areas where no adhesive layer is formed from the four sides excluding the four corners of the outer edge of the filter body 11 to the four sides excluding the four corners of the outer edge of the adhesive main layer 12a form a band-shaped gusset portion 11b extending along the four sides of the filter body 11. Because gusset portions 11b are provided along the outer edges of the four sides of filter structure 10, when filter structure 10 is cut into rectangular slits from a roll-shaped sheet body, adhesive does not adhere to the slit blade, preventing effects on productivity such as the filter structure not being able to be cut properly with the blade.

[0041] As shown in FIG. 3, the width of the tab 11a is determined by the distance A from the outer edge of each of the four corners of the filter body 11 to the outer edge of the adhesive layer 12, and the distance A is 9 mm or more and 35 mm or less. In the illustrated example, distance A corresponds to the length of a line segment that bisects the apex angle of the filter body, with one end being the outer edge of the filter body 11 and the other end being the outer edge of the adhesive layer 12. If the distance A of the tab 11a exceeds 35 mm, there is a risk that the filter structure 10 will peel off and fall off from the ventilation device, starting from the tab 11a. If the distance A of the gripping portion 11a is less than 9 mm, it may be difficult to grip the gripping portion 11a and peel off the release sheet 13.

[0042] As shown in FIG. 3, the width of the gusset portion 11b is determined by a distance B from the outer edges of the four sides of the filter body 11 to the outer edge of the adhesive layer 12, where distance B<distance A. In the illustrated example, distance B corresponds to the shortest distance (length of a perpendicular line) from a side of filter body 11 to the outer edge of adhesive layer 12. Generally, when the gusset portion 11b is formed, the distance B is about 5 mm, and therefore, when the distance A has the length described above, such an inequality holds. The distance B is preferably 1 mm or more and 9 mm or less. If the distance B is less than 1 mm, the width will be too small, and depending on the dimensional variation of the filter structure 10, there is a risk that the adhesive will adhere to the blade when cutting by slitting. If the distance B exceeds 9 mm, the filter body 11 may rise up from the ventilation device when attached to the ventilation device, which may encourage the filter body 11 to fall off. EXAMPLES

[0043] The present invention will be described in more detail below with reference to examples, comparative examples and reference examples. The following filter structures were prepared for the Examples, Comparative Examples, and Reference Examples.

[0044] In addition, all filter structures have a basis weight of 40 g / m 2 The filter has a three-layer structure consisting of a nonwoven fabric filter body, an adhesive layer, and a release sheet. The adhesive layer pattern was a square shape with four missing corners as shown in the figures in Examples 1 to 5, and a square shape with four right-angled corners (similar to the outer edge of the filter body) in Comparative Examples 1 to 3, and the width of the adhesive layer was 10 mm in all cases. The adhesive layer did not have a replacement time indicator. The overall dimensions of the filter structures were all 160 mm x 160 mm.

[0045] Example 1 ·Distance A: 13mm ·Distance B: 5mm Release sheet thickness: 15μm Example 2 Distance A: 9mm ·Distance B: 5mm Release sheet thickness: 3μm Example 3 ·Distance A: 30mm ·Distance B: 5mm Release sheet thickness: 40μm Example 4 ·Distance A: 21.2mm ·Distance B: 15mm Release sheet thickness: 15μm Example 5 ·Distance A: 35mm ·Distance B: 5mm Release sheet thickness: 15μm Comparative Example 1 ·Distance A: 7mm ·Distance B: 5mm Release sheet thickness: 15μm Comparative Example 2 ·Distance A: 0mm ·Distance B: 0mm Release sheet thickness: 15μm Comparative Example 3 ·Distance A: 7mm ·Distance B: 5mm Release sheet thickness: 50μm Reference example 1 ·Distance A: 7mm ·Distance B: 5mm Release sheet thickness: 140μm

[0046] The filter structures of the Examples, Comparative Examples, and Reference Examples were subjected to a test for ease of peeling off the release sheet. The peeling time was defined as the time required from the start of peeling the release sheet from the filter structure to the end of complete peeling, and the peeling time of the release sheet from each filter structure was measured with the cooperation of 10 panelists. It can be said that the shorter the peeling time, the easier it is to peel off the release sheet, and the longer the peeling time, the more difficult it is to peel off the release sheet. The results are shown in Table 1.

[0047] Further, in the filter structures of the Examples, Comparative Examples and Reference Examples, a test was conducted to check the ease of removal of the filter body from the ventilation device. Each filter structure with the release sheet removed was attached to a ventilation fan installed on the ceiling of the bathroom, and then a sensory evaluation was conducted on the ease of removal by selecting either "easy to remove" or "difficult to remove." The results are shown in Table 1. In Table 1, ○ means that the number of panelists who selected "easy to remove" was 8 to 10, △ means that the number of panelists who selected "easy to remove" was 3 to 7, and × means that the number of panelists who selected "easy to remove" was 2 or less.

[0048] Further, the filter structures of the Examples, Comparative Examples and Reference Examples were subjected to a test for effective air permeability area. For each filter structure from which the release sheet had been peeled off, the area inside the adhesive layer was taken as the effective air permeability area, and each area was measured. Further, in the filter structures of the Examples, Comparative Examples, and Reference Examples, an evaluation test was carried out to check whether the release sheet peeled off when the filter structure was folded. The filter structures of the Examples, Comparative Examples, and Reference Examples were folded in half at the center with the release sheet facing outward, and the presence or absence of peeling of the release sheet from the adhesive layer of the filter structure was confirmed. If peeling of the release sheet occurred even in part, it was evaluated as "peeling" and if there was no peeling, it was evaluated as "not peeling." The results are shown in Table 1.

[0049] [Table 1]

[0050] The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and includes all modifications and alterations within the scope and equivalent meanings.

[0051] For example, the overall shape of the filter structure 10 and the filter body 11 is not limited to the rectangular shape of the embodiment, but may be a polygon other than a rectangle or a circle. The pattern and shape of the adhesive main layer 12a of the adhesive layer 12 is not limited to the rectangular ring shape of the embodiment, but may be a polygonal ring or a circular ring shape other than a rectangular ring, and another adhesive main layer may be included on the inner side of the adhesive main layer 12a. The filter structure 10 has a filter body 11, an adhesive layer 12, and a release sheet 13 as minimum components, and other layers may be added to these components. The shapes, positions and numbers of the tabs 11a and gussets 11b are not limited to those in the embodiment. The shape of the replacement time indicator 12b is not limited to the heart shape of the embodiment, but may be a character pattern or letters as in the example of FIG. 5 described later, or may be omitted as in the example of FIG. 4 described later.

[0052] With this in mind, another example filter structure 10 is shown in FIG. In this example, a circular annular adhesive main layer 12a is formed on the inner side of the substantially square annular (square-shaped) adhesive main layer 12a of the embodiment shown in FIG. Since the annular adhesive layer 12a is located in a position that contacts (or may be in close proximity to) the central portions of each side of the approximately rectangular adhesive layer 12a, even if the formation of the knob portions 11a on the filter body 11 raises the risk of a decrease in adhesive strength at the four corners of the filter body 11, the annular adhesive layer 12a also contributes to the attachment of the peripheral portions of the four corners of the filter body 11 to the ventilation device. That is, the annular adhesive main layer 12a also contributes to adhesion. Furthermore, in this embodiment, the adhesive strength of the adhesive main layer 12a at the four corners of the filter body 11, which is required to prevent the filter body 11 from peeling off from the ventilation device, is smaller than in the case where the annular adhesive main layer 12a is not provided. This makes it possible to better prevent the filter body 11 from falling off due to peeling off at the four corners. In this example, the replacement time display portion 12b is not formed.

[0053] FIG. 5 shows yet another example of a filter structure 10. In this example, a lattice-shaped adhesive main layer 12a is formed on the inner side of the substantially square ring-shaped (square-shaped) adhesive main layer 12a of the embodiment shown in FIG. As in the case of FIG. 4, this lattice-shaped adhesive main layer 12a can prevent the filter body 11 from falling off due to peeling at the four corners. The replacement time indicator 12b includes a pair of heart-shaped indicators scattered at appropriate locations, as well as the words "replace" that are affixed point-symmetrically with respect to the center of the filter structure 10. In this example, not only the four corners of the substantially square ring-shaped adhesive main layer 12a but also the midpoints of the four sides and the lattice angles of the lattice-shaped adhesive main layer 12a in the center of the filter structure 10 are oblique. In this way, the filter structure 10 can be easily cut into smaller filter structures using the diagonal lattice corners as guides in accordance with the dimensions of the ventilation system. Even after cutting, the diagonal lattice corners automatically form knob portions 11a at the corners (in the drawings, the leader line for knob portions 11a after cutting is shown as a dashed line), making it easier to peel off the release sheet and improving convenience. Of course, it is also possible to combine the circular adhesive main layer 12a in FIG. 4 with the lattice-shaped adhesive main layer 12a in FIG.

[0054] Yet another example filter structure 10 is shown in FIG. In this example, the filter body 11 has a circular shape in a plan view. The adhesive layer 12 is generally annular along the outer edge of the filter body 11 at a slight distance, but has a portion cut out in a straight line. The area where the adhesive layer 12 is not formed, from the outer edge of the filter body 11 to the outer edge of the linearly cut-out portion of the adhesive layer 12, serves as a tab 11a. Further, the area where the adhesive layer 12 is not formed, from the outer edge of the filter body 11 to the outer edge of the other area of ​​the adhesive layer 12, serves as a gusset portion 11b.

[0055] The width of the tab 11a is determined by the distance A from the outer edge of the filter body 11 to the outer edge of the linearly cut-out portion of the adhesive layer 12, and the distance A is 5 mm or more and 35 mm or less. 9 mm or more is more preferable. The reason for setting it in this manner is the same as in the case of the polygon. The width of the gusset portion 11b is determined by the distance B from the outer edge of the filter body 11 to a portion other than the notched portion of the adhesive layer 12, and as is clear from the drawing, the distance B is smaller than the distance A. The distance B is preferably 1 mm or more and 8 mm or less. The reason for setting it in this manner is the same as in the case of the polygon. By pinching the tab 11a, the release sheet 13 can be easily peeled off. In this example as well, it is possible to add the annular adhesive main layer 12a in FIG. 4, the lattice-shaped adhesive main layer 12a in FIG. 5, or a combination thereof. [Explanation of symbols]

[0056] 10 Filter Structure 11 Filter body 11a Knob 11b Gusset 12 Adhesive layer 12a Adhesive layer 12b Replacement time display section 13 Release sheet

Claims

1. A filter structure that is attached to a ventilation system to prevent contamination of the system, the filter structure is polygonal in plan view; Filter body, An adhesive layer made of an adhesive partially formed on one surface of the filter body; The adhesive layer is provided with at least a release sheet laminated thereon, a tab portion on which the adhesive layer is not formed is formed on a part of an outer edge of the filter body, The width of the gripping portion is defined by a distance A from the outer edge of the filter body to the outer edge of the adhesive layer located more inward than the outer edge of the filter body, and the distance A is 9 mm or more and 35 mm or less.

2. A filter structure that is attached to a ventilation system to prevent contamination of the system, The filter structure is circular in plan view; Filter body, An adhesive layer made of an adhesive partially formed on one surface of the filter body; The adhesive layer is provided with at least a release sheet laminated thereon, a tab portion on which the adhesive layer is not formed is formed on a part of an outer edge of the filter body, The width of the gripping portion is defined by a distance A from the outer edge of the filter body to the outer edge of the adhesive layer located more inward than the outer edge of the filter body, and the distance A is 5 mm or more and 35 mm or less.

3. a gusset portion on which the adhesive layer is not formed is formed at a position different from the grip portion along an outer edge of the filter body, The filter structure according to claim 1 or 2, wherein the width of the gusset portion is defined by a distance B from the outer edge of the filter body to the outer edge of the adhesive layer located further inward than the outer edge of the filter body, and distance B < distance A holds.

4. The distance A of the knob portion is 9 mm or more and 30 mm or less, The filter structure according to claim 3 , wherein the distance B of the gusset portion is 1 mm or more and 8 mm or less.

5. The filter body is polygonal in plan view, The distance A is the length of a line segment that bisects the apex angle of the filter body, one end of which is the outer edge of the filter body and the other end of which is the outer edge of the adhesive layer, The filter structure according to claim 3 , wherein the distance B is the shortest distance from a side of the filter body to an outer edge of the adhesive layer.

6. The filter body is rectangular; 2. The filter structure according to claim 1, wherein the knobs are formed at four corners of a rectangular filter body.

7. The filter body is rectangular; The knobs are formed at the four corners of the rectangular filter body, 4. The filter structure according to claim 3, wherein the gusset portions are formed along each of the four sides of the rectangular filter body.

8. The thickness of the filter body is 0.2 mm or more and 10 mm or less, 3. The filter structure according to claim 1, wherein the release sheet has a thickness of 0.001 mm or more and 0.050 mm or less.

9. 3. The filter structure according to claim 1, wherein the adhesive layer has a replacement time indicator for indicating the time to replace the filter structure based on a dirt pattern on the filter body.

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