JPWO2020145345A1 - Air filter - Google Patents

Abstract

Provided is an air filter filled with a filler in charge of activation, which has improved adsorption efficiency and sustainability while suppressing an increase in pressure loss. The air filter of the present invention is a planar air filter having a first surface and a second surface, and has a corrugated honeycomb structure (1) defining a plurality of cells (30) arranged in the surface direction. The plurality of cells (30) include a plurality of porous fillers (50) filled in the plurality of cells (30), and the plurality of cells (30) include a plurality of minimum diameter cells (31) and a plurality of large diameter cells (first). It is composed of one large diameter cell (32) and a second large diameter cell (33), and the plurality of minimum diameter cells are cells having the smallest diameter of the inscribed circle, and the plurality of large diameter cells are inscribed. The number of minimum diameter cells (31) filled with the filler, which is a cell in which the diameter of the circle is larger than the diameter of the inscribed circle of the plurality of minimum diameter cells and occupies the number of the minimum diameter cells (31). The ratio of the number of large-diameter cells to the number of the large-diameter cells is 25 to 100%, and the ratio of the number of large-diameter cells filled with the filler is 25 to 100%.

Description

The present invention relates to an air filter used for a purpose such as deodorization.
This application claims priority based on application number 201910020245.3., Which was filed with the China National Intellectual Property Office on January 9, 2019, and the contents thereof are incorporated herein by reference.

As an air filter used for the purpose of deodorizing in an air purifier or the like, a corrugated honeycomb structure in which a large number of cells are formed by alternately stacking a plurality of liner members and a plurality of corrugated members is known. ..
The air to be treated is purified by adsorbing malodorous components and the like on the corrugated honeycomb structure while passing through the cell.
As the material of the corrugated honeycomb structure, paper to which an adsorbent is attached or contained is usually used.
Further, for the purpose of improving adsorption efficiency and sustainability, a deodorizing filter in which a cell of a corrugated honeycomb structure is filled with activated carbon or the like has also been proposed (Patent Document 1).

Japanese Unexamined Patent Publication No. 2003-47649

However, as in Patent Document 1, in order to fill the cell with activated carbon or the like, a cell having a certain size is required. In that case, the air to be treated cannot sufficiently contact the corrugated honeycomb structure while passing through the cell, and it becomes difficult to exhibit the immediate adsorption performance which is an advantage of the corrugated honeycomb structure.

If activated carbon or the like is made finer, it is possible to fill the cell without making it too large. However, in that case, the cell becomes clogged with fine activated carbon or the like, and the pressure loss becomes very high.
Therefore, the air filter in which the cells of the corrugated honeycomb structure are filled with activated carbon or the like as in Patent Document 1 has not been put into practical use.

The present invention has been made in view of the above circumstances, and provides an air filter having improved adsorption efficiency and sustainability by filling with a filler such as activated carbon while suppressing an increase in pressure loss. Is the subject.

In order to achieve the above problems, the present invention has adopted the following configuration.
[1] A planar air filter having a first surface and a second surface.
A corrugated honeycomb structure demarcating a plurality of cells arranged in a plane direction and a plurality of porous fillers filled in the plurality of cells are provided.
The plurality of cells consist of a plurality of minimum diameter cells and a plurality of large diameter cells.
The plurality of minimum diameter cells are the cells having the smallest diameter of the inscribed circle.
The plurality of large-diameter cells are cells in which the diameter of the inscribed circle is larger than the diameter of the inscribed circle of the plurality of minimum-diameter cells.
The ratio of the number of the minimum diameter cells filled with the filler to the number of the minimum diameter cells is 50% or less.
An air filter characterized in that the ratio of the number of large-diameter cells filled with the filler to the number of large-diameter cells is 25 to 100%.
[2] The air filter according to [1], wherein the ratio of the minimum diameter cell to the plurality of cells is 10 to 90 area%.
[3] The corrugated honeycomb structure is configured such that a plurality of liner members and a plurality of corrugated members are bonded to each other.
The plurality of liner members are linear when observed from a direction perpendicular to the plane direction.
The plurality of corrugated members have a wavy shape in which peaks and valleys repeat along the direction in which the liner member extends when observed from a direction perpendicular to the plane direction.
The air filter according to [1] or [2], wherein the plurality of corrugated members include two or more types of corrugated members having different heights and pitches of the corrugated shape.
[4] The air filter according to [3], wherein the plurality of corrugated members include a pair or more of corrugated members in which mountain portions are directly adhered to each other without interposing the liner member.
[5] The air filter according to any one of [1] to [4], wherein the adsorbent is held in the corrugated honeycomb structure.
[6] The air filter according to any one of [1] to [5], wherein the plurality of fillers are spherical.
[7] The air filter according to any one of [1] to [6], wherein the filler is activated carbon.
[8] The air filter according to any one of [1] to [7], wherein a breathable sheet is arranged on one or both of the first surface and the second surface.

According to the air filter filled with a filler such as activated carbon of the present invention, it is possible to improve the adsorption efficiency and sustainability while suppressing the increase in pressure loss.

It is a top view of the corrugated honeycomb structure used for the air filter which concerns on one Embodiment of this invention. It is a partially enlarged view of the corrugated honeycomb structure of FIG. It is sectional drawing of the air filter which concerns on one Embodiment of this invention. It is an enlarged photograph of the air filter which concerns on Example.

The air filter of the present invention includes a corrugated honeycomb structure that demarcates a plurality of cells arranged in the plane direction, and a plurality of porous fillers filled in the plurality of cells.
FIG. 1 is a view of the corrugated honeycomb structure 1 used in the air filter according to the embodiment of the present invention as viewed from a direction perpendicular to the plane direction. The corrugated honeycomb structure 1 is composed of a liner member 10 and a corrugated member 20, and is a planar body in which the front side of the paper surface in FIG. 1 is the first surface 61 and the back side of the paper surface is the second surface 62.
The thickness of the corrugated honeycomb structure (the length of the corrugated honeycomb structure in the depth direction, which will be described later) may be adjusted in the range of 5 to 100 mm, and is usually 5 to 50 mm.

As shown in FIG. 1, the liner member 10 is a strip-shaped member which looks linear or substantially linear when observed from a direction perpendicular to the plane direction and has a width in the paper surface thickness direction of FIG.
As shown in FIG. 1, the corrugated member 20 has a corrugated shape in which strip-shaped members are repeatedly bent and peaks and valleys are repeated along the direction in which the liner member 10 is stretched when observed from a direction perpendicular to the plane direction. It is a shaped member.

In this embodiment, two types of corrugated members 20 are used, a small corrugated member 21 and a large corrugated member 22. The pitch and height of the large corrugated member 22 is larger than the pitch and height of the small corrugated member 21.
As shown in FIG. 2, the valley portion 21b of the small corrugated member 21 is adhered to one liner member 10, and the mountain portion 21a is adhered to the other liner member 10.
On the other hand, the valley portion 22b of the large corrugated member 22 is adhered to one liner member 10, but the mountain portion 22a is attached to the other large corrugated member 22 without going through the other one liner member 10. It is directly adhered to the mountain portion 22a of.

As shown in FIGS. 1 and 2, the corrugated honeycomb structure 1 is formed so that a plurality of cells 30 defined by the liner member 10 and the corrugated member 20 are arranged in the plane direction.
In the present embodiment, as the cell 30, a minimum diameter cell 31 and two types of large diameter cells (first large diameter cell 32 and second large diameter cell 33) are formed.
The minimum diameter cell 31 is a space defined by the liner member 10 and the small corrugated member 21. The first large-diameter cell 32 is a space defined by the liner member 10 and the large corrugated member 22. Further, the second large-diameter cell 33 is a space defined by a pair of large corrugated members 22 to which the mountain portions 22a are directly adhered to each other.

In FIG. 2, the minimum diameter inscribed circle 41 is the inscribed circle of the minimum diameter cell 31, the first large diameter inscribed circle 42 is the inscribed circle of the first large diameter cell 32, and the second large diameter inscribed circle 42. The circle 43 is the inscribed circle of the second large-diameter cell 33.
Of these inscribed circles, the diameter of the smallest diameter inscribed circle 41 is the smallest, and the diameters of the first large diameter inscribed circle 42 and the second large diameter inscribed circle 43 are larger than the diameter of the smallest diameter inscribed circle 41. big. Further, the diameter of the second large diameter inscribed circle 43 is larger than the diameter of the first large diameter inscribed circle 42.

Since the minimum diameter cell 31 inscribed by the minimum diameter inscribed circle 41 has a small opening area, it is difficult for the filler to be filled and the gas can pass smoothly. Further, since the minimum diameter cell 31 has a small opening area, the gas passing through the minimum diameter cell 31 can sufficiently contact the liner member 10 and the small corrugated member 21, and the malodorous component or the like is adsorbed on these members. Cheap.

Further, the first large-diameter cell 32 and the second large-diameter cell 33, in which the inscribed circle having a diameter larger than the minimum-diameter inscribed circle 41 is inscribed, have a sufficient size of filler that is difficult to enter into the minimum-diameter cell 31. Can be filled. Therefore, the adsorption efficiency and sustainability can be improved by the filler while suppressing the increase in pressure loss.
Further, when there are a plurality of types of large-diameter cells (first large-diameter cell 32, second large-diameter cell 33) having different diameters of the inscribed circles as in the present embodiment, the effect of suppressing an increase in pressure loss is obtained. In addition to further increasing, it is possible to prevent clogging at the same time when used for a long period of time. In addition, it is easy to fill a plurality of types of fillers having different sizes. Therefore, it is easy to use a plurality of types of fillers having different adsorption characteristics.

The ratio of the total area of the minimum diameter cell 31 to the total area (100%) of the cells 30 in the corrugated honeycomb structure 1 (meaning the ratio (area%) of the minimum diameter cell 31 to the plurality of cells 30 of the corrugated honeycomb structure 1). ) Is preferably 10 to 90%, more preferably 15 to 75%, and even more preferably 20 to 50%.
When the ratio is at least a preferable lower limit value, it is easy to secure air permeability and suppress an increase in pressure loss. Further, when the ratio is not more than the preferable upper limit value, it is easy to fill the first large diameter cell 32 and the second large diameter cell 33 with a sufficient amount of filler.
The total area of the first large-diameter cell 32 and the total area of the second large-diameter cell 33 may be appropriately adjusted according to the blending amount for each size of the filler to be filled.

It is preferable that the minimum diameter cell 31, the first large diameter cell 32, and the second large diameter cell 33 are distributed as evenly as possible in the direction in which the liner members 10 are arranged. As a result, it is possible to prevent the pressure loss from being partially increased.

The diameter of the minimum diameter inscribed circle 41 is preferably 0.5 to 3 mm, more preferably 1 to 2.5 mm, and even more preferably 1.5 to 2.0 mm.
When the diameter of the minimum diameter inscribed circle 41 is equal to or greater than the lower limit of the preferable range, it is difficult to prevent the gas passage of the minimum diameter cell 31. If the diameter of the minimum diameter inscribed circle 41 is equal to or less than the upper limit of the preferable range, the gas passing through the minimum diameter cell 31 is sufficiently brought into contact with the corrugated honeycomb structure 1, and the malodorous component or the like is transferred to the corrugated honeycomb structure 1. It can be adsorbed.

The diameter of the first large diameter inscribed circle 42 and the second large diameter inscribed circle 43 is preferably 1.1 times or more, preferably 1.5 times or more the diameter of the minimum diameter inscribed circle 41. More preferred.
When the ratio is more than the above preferable ratio, it is easy to fill the first large-diameter cell 32 and the second large-diameter cell 33 with the filler while suppressing the filling of the filler in the minimum-diameter cell 31.

The diameter of the first large-diameter inscribed circle 42 is preferably 1 to 6 mm, more preferably 1 to 4 mm, and even more preferably 2 to 3 mm.
When the diameter of the first large diameter inscribed circle 42 is equal to or greater than the lower limit of the preferable range, the first large diameter cell 32 can be easily filled with the filler. When the diameter of the first large-diameter inscribed circle 42 is not more than the upper limit of the preferable range, the area of the first large-diameter cell 32 does not become excessive, and it is easy to secure the strength of the corrugated honeycomb structure 1.

The diameter of the second large-diameter inscribed circle 43 is preferably 1.1 times or more, more preferably 1.25 times or more the diameter of the first large-diameter inscribed circle 42.
When the ratio is more than the above preferable ratio, it is easy to fill the fillers of different sizes by using the first large diameter cell 32 and the second large diameter cell 33.

The pitch and height of the corrugated shape of the small corrugated member 21 can be determined so that the diameter of the minimum diameter inscribed circle 41 becomes the preferable value.
Specifically, the pitch of the corrugated shape of the small corrugated member 21 is preferably 2 to 7 mm, more preferably 3 to 6 mm.
The height of the corrugated shape of the small corrugated member 21 is preferably 0.5 to 3 mm, more preferably 1 to 2.5 mm.
The height of the corrugated shape of the small corrugated member 21 is the distance between the valley portion 21b and the mountain portion 21a on one surface of the small corrugated member 21 in the height direction, and the height direction is defined as the liner member 10. The directions are orthogonal.

Further, the pitch and height of the corrugated shape of the large corrugated member 22 can be determined so that the diameters of the first large diameter inscribed circle 42 and the second large diameter inscribed circle 43 are the preferable values.
Specifically, the wavy pitch of the large corrugated member 22 is preferably 4 to 12 mm, more preferably 5 to 10 mm.
The height of the corrugated shape of the large corrugated member 22 is preferably 2 to 6 mm, more preferably 2.5 to 5 mm.
The height of the corrugated shape of the large corrugated member 22 is the distance between the valley portion 22b and the mountain portion 22a on one surface of the large corrugated member 22 in the height direction, and the height direction is defined as the liner member 10. The directions are orthogonal.

The liner member 10 and the corrugated member 20 of the corrugated honeycomb structure 1 are preferably composed of a base material and an adsorbent held on the base material.
The base material is not particularly limited as long as it is a sheet-shaped base material such as papers, non-woven fabrics, and plastic films, but a fiber base material is preferable from the viewpoint of easily holding an adsorbent. Examples of the fiber base material include a paper base material containing cellulose fiber as a main component and a plastic base material containing synthetic fiber as a main component. Of these, a paper base material containing cellulose fibers as a main component is preferable.
In addition, "as a main component" means that the ratio to the whole base material is 50% by mass or more.

The paper substrate is typically composed of pulp containing cellulose fibers. Examples of pulp containing cellulose fibers include wood pulp and non-wood pulp. Examples of wood pulp include softwood pulp and hardwood pulp. Examples of non-wood pulp include hemp pulp, kenaf pulp, bamboo pulp and the like.

The wood pulp may have undergone a cooking step and / or a bleaching step. Generally, wood pulp is used by subjecting it to various cooking steps and bleaching steps in order to remove components other than cellulose from the raw wood. In the present invention, the cooking step and the bleaching step are not particularly limited, and a known method can be used as appropriate.
These pulps may be used alone or in combination of two or more.

The paper substrate may further contain fibers other than the cellulose fibers. Examples of other fibers include synthetic fibers such as rayon fiber, polyethylene fiber, polypropylene fiber and polyester fiber, inorganic fiber such as glass fiber, ceramic fiber and mineral fiber, and animal fiber.
The paper substrate may contain an internal chemical such as a sizing agent, a paper strength enhancer, a colorant, a preservative, and a flame retardant. As the internal medicine, a known one can be used.

Examples of the plastic base material include those containing one or more synthetic fibers such as rayon fiber, polyethylene fiber, polypropylene fiber, and polyester fiber as the main component.
The basis weight of the base material is preferably 10 to 500 g / ^{m 2,} more preferably from 10 to 400 g / ^{m 2,} further preferably 10 to 300 g / ^{m 2.}
The fiber base material is preferably obtained by the papermaking method.

Examples of the adsorbent to be retained on the substrate include activated carbon such as granular, powder and fibrous, zeolites such as mordenite, ferrierite and molecular sieves, silica gel and known adsorbents such as alumina gel. These adsorbents may carry a chemical that reacts with the component to be removed (for example, a compound that reacts with ammonia or formaldehyde). Further, a chemical that reacts with the component to be removed may be directly supported on the base material.
The adsorbent to be retained on the substrate may be retained inside the substrate, adhered to the surface, or may be present both inside and on the surface.
The adsorbent to be retained on the substrate may be internally added at the time of papermaking, or may be applied or impregnated after papermaking.

The method for manufacturing the corrugated honeycomb structure 1 is not particularly limited, but a single corrugated cardboard (hereinafter referred to as “small corrugated cardboard”) in which a small corrugated cardboard member 21 is bonded to a liner member 10 and a large corrugated cardboard 22 are bonded to the liner member 10. It is preferable to stack and bond the corrugated cardboard (hereinafter referred to as "large corrugated cardboard").

Further, in the large piece corrugated cardboard, the mountain portions 22a of the pair of large corrugated members 22 are adhered to each other, the pair of large corrugated members 22 are adhered between the pair of liner members 10, and the mountain portions 22a of the pair of large corrugated members 22 are adhered to each other. It is preferable to form a structure sandwiched in the above-mentioned state (hereinafter referred to as “X-structured flute”; in the present embodiment, the X-structured flute 70 in FIG. 2), and to laminate and bond the X-structured flute 70 and the small piece of corrugated cardboard.

In the case of laminating and adhering the X-structured flute 70 and the small piece of corrugated cardboard, the liner member 10 of the X-structured flute 70 and the liner member 10 of the small piece of corrugated board may be overlapped. Further, the small corrugated board member 21 side of the small corrugated cardboard is adhered to the liner member 10 of the X-structured flute 70, and the liner member 10 of the small corrugated cardboard and the liner member 10 of another small corrugated cardboard are laminated and bonded so as to overlap each other. May be good.
That is, when the corrugated honeycomb structure 1 is manufactured by laminating and adhering a small piece of corrugated cardboard and an X-structured flute, a portion in which a liner member 10 constituting one piece of corrugated board exists alone and two pieces constituting a pair of piece of corrugated board are formed. A portion existing in a state of being overlapped with the liner member 10 of the above is formed.

FIG. 3 is a schematic cross-sectional view of the air filter according to the embodiment of the present invention. In the air filter of FIG. 3, a plurality of porous fillers 50 are filled in the cells 30 of the corrugated honeycomb structure 1 shown in FIGS. 1 and 2, and the first surface 61 and the second surface of the corrugated honeycomb structure 1 are filled. A breathable sheet 71 and a breathable sheet 72 are arranged in 62, respectively.

Since the filler 50 is porous, it has an ability to adsorb components for removing malodor and the like. Examples of the filler 50 include activated carbon such as granular, powder, and fibrous, zeolite such as mordenite, ferrierite, and molecular sieves, silica gel, and alumina gel. Of these, activated carbon is preferable, granular activated carbon is more preferable, and spherical or substantially spherical activated carbon is particularly preferable.

The filler 50 may carry a chemical that reacts with a component to be removed, such as an inorganic acid.
The filler 50 is preferably granular, more preferably substantially spherical, and particularly preferably spherical. If it is spherical or substantially spherical, it is easy to fill the cell 30, and an appropriate gap is formed between the liner member 10 and the corrugated member 20 that demarcate the cell 30, and it is easy to secure ventilation.

The average particle size of the filler 50 is preferably 500 to 10000 μm, more preferably 1000 to 5000 μm. The average particle size is measured by the mass average particle size method in accordance with JIS K1474 (activated carbon test method-average particle size measurement method).

The specific surface area of the filler 50 ^{is preferably 600 to 2200 m 2} / g. The specific surface area is the BET specific surface area measured by the nitrogen gas adsorption method.
When the specific surface area of the filler 50 is at least the above-mentioned preferable lower limit value, it is easy to exhibit the adsorption performance of malodorous components and the like. Further, when the specific surface area of the filler 50 is equal to or less than the preferable upper limit value, the strength of the filler 50 can be easily maintained.

The ratio (filling rate) of the number of the minimum diameter cells 31 filled with the filler 50 to the number of the minimum diameter cells 31 (100%) is preferably 50% or less, and more preferably 25% or less. It is preferably 10% or less, and more preferably 10% or less.
When the filling rate of the minimum diameter cell 31 is not more than the preferable upper limit value, it is easy to secure the air permeability.
In order to make the filling rate of the minimum diameter cell 31 equal to or less than the preferable upper limit value, the ratio of the filler 50 having a diameter smaller than that of the minimum diameter inscribed circle 41 to the entire filler 50 may be reduced.
The lower limit of the filling rate of the minimum diameter cell 31 may be 0%. That is, the minimum diameter cell 31 may not be filled with the filler 50.

On the other hand, the ratio (filling rate) of the number of large-diameter cells filled with the filler 50 to the number (100%) of the large-diameter cells (first large-diameter cell 32 and second large-diameter cell 33 in the case of the present embodiment). ) Is preferably 25 to 100%, more preferably 50 to 100%, and even more preferably 75 to 100%.
When the filling rate of the large-diameter cell is equal to or higher than the preferable lower limit value, the filler 50 can easily increase the adsorption efficiency and sustainability. If the filling rate of the large-diameter cell is equal to or less than the preferable upper limit, the filling operation is easy.
In determining the filling factor, regardless of the size of the filler 50, a cell filled with at least one is regarded as a filled cell.

FIG. 3 schematically shows an example in which a spherical small filler 51 and a large filler 52 larger than the small filler 51 are filled as the filler 50.
The diameter of the small filler 51 is preferably larger than the minimum diameter inscribed circle 41. This makes it difficult for the small filler 51 to fill the minimum diameter cell 31.
Even if the diameter of the filler 50 is larger than the minimum diameter inscribed circle 41, the minimum diameter cell 31 may be filled with the filler 50 or the like as fragments due to cracking or the like.

Since the filler 50 is filled in the cell 30, any diameter is smaller than the second large diameter inscribed circle 43. Further, the diameter of the large filler 52 is preferably larger than that of the first large diameter inscribed circle 42. As a result, the large-diameter cell 52 can be easily filled with the large-diameter cell 33, and the filling rate of the second large-diameter cell 33 can be improved.

The breathable sheet 71 and the breathable sheet 72 are made of a breathable material such as a non-woven fabric or a mesh cloth. Examples of the material constituting the non-woven fabric, mesh cloth, etc. include rayon, polyester, nylon, and the like.
The breathable sheet 71 and the breathable sheet 72 are arranged so as to be adhered to the first surface 61 value and the second surface 62 of the corrugated honeycomb structure 1, respectively.
By locating the breathable sheet 71 and the breathable sheet 72, it is possible to prevent the filler 50 from falling off from the air filter. In addition, dust and the like can be removed from the gas passing through the air filter.

In FIGS. 1 and 2, the corrugated honeycomb structure 1 having the X-structured flute 70 is used, but it is not always necessary to have the X-structured flute 70. For example, three types of corrugated cardboard of different sizes may be used in combination and laminated.
Further, the large-diameter cell is not limited to two types as shown in FIGS. 1 and 2, and may be one type or three or more types.
Further, the shape of the cell 30 is not particularly limited.
Further, in FIGS. 1 and 2, the large corrugated member 22 and the small corrugated member 21 have different configurations in both pitch and height, but a plurality of types of corrugated members 20 having different pitch and height are used. May be good.
Further, as long as the cell 30 can include cells having different sizes, the corrugated member 20 may be of one type. For example, a plurality of X-structured flutes created using one type of corrugated cardboard may be laminated.
Further, the shape and size of the filler 50 are not limited to two types as shown in FIG. 3, and may be three or more types.

[Example 1]
A liner base paper is made of glass fiber mixed paper with a basis weight of 50 g / m ² (manufactured by Oji F-Tex) and impregnated with an adsorbent dispersion containing activated carbon, an inorganic adsorbent, a chemical adsorbent, etc. at a ratio of 200 g / L. It was made into a member.
Glass fiber mixed paper (manufactured by Oji Ftex) with a basis weight of 50 g / m ² is used as corrugated base paper, and is impregnated with an adsorbent dispersion containing activated carbon, an inorganic adsorbent, a chemical adsorbent, etc. at a ratio of 200 g / L. It was used as a base material for corrugated use.
After the corrugated base material was corrugated to form a corrugated member, a liner member and a laminated piece corrugated cardboard were formed. Two types of corrugated cardboard, small corrugated cardboard and large corrugated cardboard, with different heights and pitches were prepared. For the small corrugated cardboard, a small corrugated member having a pitch of 4.9 mm and a height of 2 mm was used, and for the large corrugated cardboard, a large corrugated member having a pitch of 5.9 mm and a height of 3 mm was used.

The two obtained large pieces of corrugated cardboard are bonded together so that the ridgelines of the large corrugated cardboards are aligned with each other so that the liner members are on both outer sides, and the corrugated members of the small pieces of corrugated board are bonded to the liner members on both outer sides. Got A plurality of these laminated bodies were stacked to obtain a corrugated honeycomb structure equivalent to that shown in FIG. In addition, each piece of corrugated cardboard was laminated by aligning the ridge line direction of the corrugated member. The thickness of the corrugated honeycomb structure (length in the depth direction of the cell) was set to 15 mm.

A breathable sheet was adhered to one surface of the obtained corrugated honeycomb structure, and from the other surface, a chemical-supported spherical activated carbon manufactured by Osaka Gas Chemical Co., Ltd. ((average particle size 2 mm, BET specific surface area 930 m)) was used as a filler. ^It was filled with 23 g of 2 / g). Then, a breathable sheet was also adhered to the other surface to obtain an air filter of Example 1.
As the breathable sheet, a polyester mesh (opening 1 mm) was used.

[Comparative Example 1]
An air filter was obtained in the same manner as in Example 1 except that only the large piece corrugated cardboard used in Example 1 had a structure in which a plurality of liner members and corrugated members were bonded to each other and laminated. In addition, a plurality of large pieces of corrugated cardboard were laminated so that the ridgeline directions of the corrugated members were aligned.

[Pressure loss evaluation]
After putting the obtained air filter in a resin case with an opening of 100 mm × 100 mm, it is set in a wind tunnel device, and each line of 0.5 m / s, 1.0 m / s, 1.5 m / s, and 2.0 m / s. The pressure loss at high speed was measured.
The results are shown in Table 1.

As shown in Table 1, it can be seen that the air filter of Example 1 is superior to Comparative Example 1 in terms of pressure loss.
FIG. 4 is an enlarged photograph taken from the other surface side of the air filter of Example 1 before adhering the breathable sheet to the other surface. As shown in FIG. 4, it was confirmed that the minimum diameter cell was hardly filled with the filler and the filling rate did not exceed 50%. Further, it was confirmed that most of the large-diameter cells could be filled with the filler, and the filling rate was at least 25% or more. In particular, the filling rate of the large-diameter cell (corresponding to the second large-diameter cell 33 in FIG. 1) having a large diameter of the inscribed circle was high.
That is, in Example 1, it was confirmed that the filler such as activated carbon could be filled while securing the cell in which the filler was not filled and the gas could easily pass through and suppressing the increase in the pressure loss.

[Comparative Example 2]
In Example 1, an air filter was obtained in the same manner as in Example 1 except that the spherical activated carbon was not filled.

[Formaldehyde removal performance evaluation]
Employing an evaluation test based on the Chinese GB standards (GB / T 18801-2015), by the simple test of the size of the test chamber was 1 m ^3, the clean air supply rate after formaldehyde loading of the air filter (CADR) and clean air Formaldehyde removal performance was evaluated by measuring the supply rate maintenance rate (CADR maintenance rate).

(Measurement of initial CADR)
An air purifier fan equipped with the air filter obtained in Example 1 and Comparative Example 2 was set, and the air purifier was sealed in a test chamber so that the aerial concentration of formaldehyde was 1 ppm, and the air purifier was the same as the target air purifier. It is operated at a linear speed (LV) of 1.0 m / s, and the formaldehyde air concentration is measured for 60 minutes at 5-minute intervals using a formaldehyde meter http. The air supply rate (initial CADR) was measured.
The results are shown in Table 2.

(Measurement of CADR after formaldehyde loading)
Next, the air-cleaning fan equipped with the air filter obtained in Example 1 and Comparative Example 2 was set, and the filter paper on the volatilization fan was impregnated with a formaldehyde solution so that the mass of formaldehyde was 20 mg. And the volatilization fan was operated and left for 12 hours.

Furthermore, an air purifier equipped with an air filter that has undergone the above treatment is set and sealed in a ^{test room (1 m 3) so that the aerial concentration of formaldehyde is 1 ppm.} It was operated at the same linear velocity (LV) of 1.0 m / s, and the formaldehyde air concentration was measured for 60 minutes at 5-minute intervals using a formaldehyde meter http. The clean air supply rate (CADR) after loading 20 mg / sheet was measured.

From the relationship between the initial clean air supply rate (initial CADR) and the clean air supply rate (CADR) after the formaldehyde 20 mg / sheet load, the clean air supply rate maintenance rate (CADR maintenance rate) after the 20 mg load was calculated.

As shown in Table 2, the air filter of Example 1 showed high adsorption performance not only at the initial stage but also after adsorption equivalent to 20 mg.

The air filter filled with a filler such as activated carbon of the present invention can improve adsorption efficiency and sustainability while suppressing an increase in pressure loss.
The air filter of the present invention can be used in an air purifier, an air conditioner, a dehumidifier, etc. for the purpose of removing malodorous components, harmful components, and the like.

1 Corrugated honeycomb structure 10 Liner member 20 Corrugated member 21 Small corrugated member 22 Large corrugated member 30 Cell 31 Minimum diameter cell 32 1st large diameter cell 33 2nd large diameter cell 41 Minimum diameter inscribed circle 42 1st large diameter inscribed circle Circle 43 Second large diameter inscribed circle 50 Filler 51 Small filler 52 Large filler 61 First surface 62 Second surface 71 Breathable sheet 72 Breathable sheet

Claims (8)

A planar air filter having a first surface and a second surface.
A corrugated honeycomb structure demarcating a plurality of cells arranged in a plane direction and a plurality of porous fillers filled in the plurality of cells are provided.
The plurality of cells consist of a plurality of minimum diameter cells and a plurality of large diameter cells.
The plurality of minimum diameter cells are the cells having the smallest diameter of the inscribed circle.
The plurality of large-diameter cells are cells in which the diameter of the inscribed circle is larger than the diameter of the inscribed circle of the plurality of minimum-diameter cells.
The ratio of the number of the minimum diameter cells filled with the filler to the number of the minimum diameter cells is 50% or less.
An air filter characterized in that the ratio of the number of large-diameter cells filled with the filler to the number of large-diameter cells is 25 to 100%. The air filter according to claim 1, wherein the ratio of the minimum diameter cell to the plurality of cells is 10 to 90 area%. The corrugated honeycomb structure is configured such that a plurality of liner members and a plurality of corrugated members are bonded to each other.
The plurality of liner members are linear when observed from a direction perpendicular to the plane direction.
The plurality of corrugated members have a wavy shape in which peaks and valleys repeat along the direction in which the liner member extends when observed from a direction perpendicular to the plane direction.
The air filter according to claim 1 or 2, wherein the plurality of corrugated members include two or more types of corrugated members having different one or both of the heights and pitches of the corrugated shape. The air filter according to claim 3, wherein the plurality of corrugated members include a pair or more corrugated members in which the mountain portions are directly adhered to each other without interposing the liner member. The air filter according to any one of claims 1 to 4, wherein the adsorbent is held in the corrugated honeycomb structure. The air filter according to any one of claims 1 to 5, wherein the plurality of fillers are spherical. The air filter according to any one of claims 1 to 6, wherein the filler is activated carbon. The air filter according to any one of claims 1 to 7, wherein a breathable sheet is arranged on one or both of the first surface and the second surface.

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