JP2019166515A - Air filter filter-material and air filter - Google Patents

Abstract

To provide an air filter filter-material and an air filter which are easily pleated, hardly change a pleat shape of the air filter under in high wind-velocity and have excellent dust-collecting performance and deodorization performance.SOLUTION: An aldehyde adsorbent having an average particle size of 1 to 50 μm is carried on nonwoven fabric which has a unit weight of 40 to 100 g/m, a thickness of 0.1 to 1.4 mm and wind pressure resistance 6.5 g or more on MD of nonwoven fabric 1 and of 4.5 g or more on CD of nonwoven fabric, or on nonwoven fabric composed of two layers of a support body layer and a dust collecting layer, the support body layer has a unit weight of 40 to 100 g/mand a thickness of 0.2 to 1.4 mm with binder, and the dust collecting layer is nonwoven fabric which is subjected to electret processing, has a unit weight of 10 to 30 g/m, has veneer pressure loss upon 5.3 cm/s, of 9.5 Pa or less, has collection efficiency of atmospheric dust of particle size upon 5.3 cm/s, of 0.3 μm or more and less than 0.5 μm, of 80% or more, wind pressure durability is 8 to 33 g on MD of air filter filter-material 1 and is 6 to 20 g on CD thereof.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an air filter medium and an air filter. More specifically, the present invention relates to an air filter medium and an air filter that can be used as an air purification filter in general rooms such as buildings and houses, automobiles, airplanes, and the like.

  In recent years, from the influence of infectious diseases caused by viruses such as influenza, such as dust from the deserts and dry areas in the inland of East Asia (yellow sand), pollen of PM2.5, cedar, cypress, etc. There are many living environments in which indoor air is purified, temperature-controlled, and humidity-controlled using air purifiers and air conditioners instead of ventilation of indoor air with windows open. In particular, there is a strong market demand for the function of improving the comfort of spaces such as homes, workplaces, and automobiles, and the use of air purification means is progressing. As familiar air purifying means, an air filter mounted on an air purifier, an air conditioner or the like is known.

Malodorous gas components present in living environments such as homes, workplaces, and automobiles include lower aldehydes such as formaldehyde and acetaldehyde, amines such as ammonia and trimethylamine, and lower odors such as acetic acid and isovaleric acid. There are fatty acids, mercaptans such as methyl mercaptan, SO ₂ , NO ₂ , aromatic hydrocarbons such as toluene and xylene, and in particular, acetaldehyde has 22 types specified by the Malodor Control Law. It falls under both of the specific malodorous substances and 13 kinds of volatile organic compounds (VOC) whose concentration guidelines are set by the Ministry of Health, Labor and Welfare.

  From these backgrounds, the air filter material, which is the material of the air filter, has a high dust collection efficiency, a pressure loss as small as possible, a long life, and a deodorizing performance of acetaldehyde. It has been demanded. In addition, a nonwoven fabric is generally used as the air filter medium, but in order to increase the contact area with air and improve the collection efficiency, the nonwoven fabric is pleated and used as an air filter. The Therefore, air filter media and air filters can be easily and reliably pleated on air filter media (pleatability), and pleated when the air filter is used at high wind speeds. The wind pressure deformation resistance etc. which can hold | maintain are required (for example, refer patent document 1).

  As an air filter medium having pleatability or wind pressure deformation resistance, an air filter medium having improved mechanical strength represented by rigidity has been proposed. As the stiffness index, “flexibility” is used. The bending resistance is defined in JIS L 1913 “General nonwoven fabric test method”, JIS L 1096 “Fabric and knitted fabric test method” and the like, and is constant as an air filter medium having pleatability and wind pressure deformation resistance. An air filter medium composed of a non-woven fabric satisfying a bending resistance greater than or equal to the value is disclosed. As a method for measuring the bending resistance, a cantilever method, a Gurley method, a handle ohm method, a slide method, or the like is used (for example, see Patent Documents 2 to 6). However, when the applicant has studied, even air filter media composed of non-woven fabric with a bending resistance specified by JIS standards exceeding a certain value is used when pleating is difficult or under high wind speeds. In some cases, the pleated shape of the air filter could not be maintained.

JP 2014-100654 A1 JP 05-031310 A JP 2006-130369 A JP-A-11-293555 JP 2017-056386 A JP2015-140495A

  It is an object of the present invention to provide an air filter medium that can provide an air filter that is easy to pleat and is less likely to change its pleat shape when used at high wind speeds. It is another object of the present invention to provide an air filter medium and an air filter having excellent dust collection performance and deodorization performance.

  The problems according to the present invention can be solved by the following means.

(I) The basis weight is 40 to 100 g / m ² , the thickness is 0.1 to 1.4 mm, and the wind pressure resistance [unit: g] defined below is 6.5 g or more in the MD of the nonwoven fabric, An air filter medium comprising a nonwoven fabric having a CD of 4.5 g or more.
Wind pressure resistance: Two pedestals (57 mm wide x 40 mm deep x 155 mm high, made of polystyrene) are fixed at a distance of 52 mm, and a non-woven fabric having a long side of 140 mm and a short side of 40 mm is placed between the top plates of the two pedestals. The long side direction and the width direction of the pedestal are passed in parallel, the container is suspended from the center line in the long side direction of the nonwoven fabric, the weight is gradually added to the container, and the "mass of the container at the time the container falls + Mass of weight is defined as “wind pressure resistance”.

(II) An air filter medium composed of two layers, a support layer and a dust collection layer,
The support layer has a basis weight of 40 to 100 g / m ² and a non-woven fabric having a thickness of 0.2 to 1.4 mm, and an aldehyde adsorbent that is particles having an average particle diameter of 1 to 50 μm is supported by a binder. Non-woven,
The dust collection layer is electret processed, has a basis weight of 10 to 30 g / m ² , a single plate pressure loss at 5.3 cm / s is 9.5 Pa or less, and a particle diameter at 5.3 cm / s is 0.3 μm or more. It is a non-woven fabric with an air dust collection efficiency of less than 0.5 μm and 80% or more,
An air filter medium characterized in that the air pressure resistance [unit: g] defined below is 8 to 33 g in MD of the air filter medium and 6 to 20 g in CD.
Wind pressure resistance: Two pedestals (width 57mm x depth 40mm x height 155mm, made of polystyrene) are fixed at a distance of 52mm, and air filter media with a long side 140mm x short side 40mm is mounted on the top plate of the two pedestals The long side direction and the width direction of the pedestal are passed in parallel, the container is suspended from the center line of the long side direction of the air filter medium, weights are gradually added to the container, and the container is dropped “Mass of container + mass of weight” is defined as “wind pressure resistance”.

(III) The air filter medium according to the above (II), wherein the content of the aldehyde adsorbent is 5 to 25 g / m ² and the content of the binder is 10 to 50% by mass with respect to the aldehyde adsorbent.

(IV) The air filter medium according to (II) or (III), wherein the support layer is a chemical bond nonwoven fabric containing polyethylene terephthalate fibers or a thermal bond nonwoven fabric containing polyethylene terephthalate fibers.
(V) An air filter using the air filter medium according to any one of (I) to (IV) above.

  The air filter medium of the present invention is easy to pleat, and by using the air filter medium of the present invention, to provide an air filter in which the pleat shape of the air filter is less likely to change when used at high wind speeds. Can do. Moreover, the air filter which has the outstanding dust collection performance and deodorizing performance can be provided.

It is a figure which shows the measuring method of wind pressure tolerance. It is a figure which shows the measuring method of wind pressure tolerance.

  The air filter medium and air filter of the present invention will be described in detail below. Note that the present invention is not limited to these embodiments. Further, the “air filter medium” may be referred to as “filter medium”.

The air filter medium (I) of the present invention has a basis weight of 40 to 100 g / m ² , a thickness of 0.1 to 1.4 mm, and a wind pressure resistance [unit: g] of 6.5 g or more in the nonwoven fabric MD. It is an air filter medium characterized by being comprised with the nonwoven fabric which is 4.5 g or more in CD.

The air filter medium (II) of the present invention is an air filter medium composed of two layers, a support layer and a dust collection layer. A nonwoven fabric in which an aldehyde adsorbent that is particles having an average particle diameter of 1 to 50 μm is supported by a binder on a nonwoven fabric having a basis weight of 40 to 100 g / m ² and a thickness of 0.2 to 1.4 mm. It is. The dust collection layer is electret processed, the basis weight is 10 to 30 g / m ² , the single plate pressure loss at 5.3 cm / s is 9.5 Pa or less, and the particle diameter at 5.3 cm / s is 0.3 μm or more 0 It is a non-woven fabric with an air dust collection efficiency of less than 5 μm of 80% or more. And wind pressure tolerance [unit: g] is 8-33g in MD of an air filter medium, and is 6-20g in CD.

  In the present invention, the nonwoven fabric constituting the air filter medium (I) and the support layer and the dust collection layer of the air filter medium (II) are polyamide fibers, polyester fibers, polyalkylene paraoxybenzoate fibers, polyurethane fibers, Synthetic fibers such as polyvinyl alcohol fiber, polyvinylidene chloride fiber, polyvinyl chloride fiber, polyacrylonitrile fiber, polyolefin fiber, phenol fiber; glass fiber, metal fiber, alumina fiber, carbon fiber, activated carbon fiber, etc. Inorganic fibers: wood pulp, bamboo pulp, hemp pulp, kenaf pulp, straw pulp, bagasse pulp, cotton linter pulp, cotton, wool, silk and other natural fibers; recycled paper fibers such as recycled paper pulp and rayon; proteins such as collagen, Alginic acid, chitin, chitosan, starch Recycled fibers such as polysaccharides and the like as a raw material of, can be used alone or in combination. These fibers may be provided with functions such as hydrophilicity and flame retardancy. The support layer contains polyethylene terephthalate fiber, which is a kind of polyester fiber, so that it can be more easily pleated and the air filter does not deform when the pleated air filter is used at high wind speeds. It is preferable.

  There are no particular restrictions on the method for producing the nonwoven fabric constituting the air filter medium (I) and the air filter medium (II) support layer and dust collecting layer. Depending on the purpose and application, the dry method, the wet papermaking method, the melt blown Web, spunbond method, flash spinning method, airlaid method, hydroentanglement method, needle punch method, stitch bond method, physical method such as thermal bond method, thermal bond method, chemical bond method, It can be produced by appropriately combining methods for developing strength by an adhesive method such as a resin bond method. The nonwoven fabric may be a single layer or a multilayer. In order to obtain an air filter medium that is more easily pleated, a chemical bond nonwoven fabric or a thermal bond nonwoven fabric is preferable.

In the air filter medium (I), the basis weight of the nonwoven fabric is 40 to 100 g / m ² , more preferably 50 to 80 g / m ² . When the basis weight is less than 40 g / m ² , the air filter may be deformed when the pleated air filter is used at a high wind speed. When the basis weight is more than 100 g / m ² , pleatability Decrease and pressure loss (pressure loss) increase.

  In the air filter medium (I), the thickness of the nonwoven fabric is 0.1 to 1.4 mm and 0.3 to 1.0 mm in order to obtain good pleatability and wind pressure deformation resistance. Is more preferable. If the thickness of the non-woven fabric is less than 0.1 mm, the physical strength is inferior, so that tearing may occur during pleating. On the other hand, if it is thicker than 1.4 mm, it becomes difficult to perform pleating. The problem of unevenness and the problem of meandering of the filter medium occur.

In the air filter medium (II), the basis weight of the nonwoven fabric of the support layer is 40 to 100 g / m ² , more preferably 50 to 80 g / m ² . When the basis weight is less than 40 g / m ² , it becomes difficult to perform pleating, and when the pleated air filter is used at high wind speed, the air filter may be deformed. When the basis weight is over 100 g / m ² In this case, a decrease in pleatability, an increase in pressure loss (pressure loss), and a decrease in dust holding amount occur.

  In the air filter medium (II), the thickness of the nonwoven fabric of the support layer is 0.2 to 1.4 mm, more preferably 0.4 to 1.0 mm. If the thickness of the nonwoven fabric is thinner than 0.2 mm, it becomes difficult to perform pleating, and the air filter may be deformed when the pleated air filter is used at a high wind speed. However, it is not necessary to be too thick, and if it is thicker than 1.4 mm, it becomes difficult to perform pleating, and there arises a problem that the peak height of the pleats is not uniform and a meandering of the filter medium occurs.

  In the air filter medium (II), as aldehyde adsorbent, natural zeolite, synthetic zeolite, activated alumina, activated clay, sepiolite, iron oxide and other iron compounds, zinc oxide, magnesium oxide, aluminum silicate, silica, silica- Examples include deodorizers such as zinc oxide composites, silica-alumina-zinc oxide composites, and composite phyllosilicates. Moreover, the mixture etc. are mentioned. More preferably, these deodorant particles are modified with a compound capable of chemisorbing aldehyde. Examples of the compound include amino compounds, saturated cyclic secondary amine compounds (for example, morpholine), azole compounds, and aromatic amino acid acidic salts (for example, o-, m-, p-aminobenzoic acid, o-, m-, p-). Aminosalicylic acid, etc.), imidazole and / or derivatives thereof, acid hydrazide compounds, polyamine compounds, aminoguanidine salt compounds, and the like.

  In the air filter medium (II), the average particle diameter of the aldehyde adsorbent is 1 to 50 μm, more preferably 3 to 20 μm. When the average particle diameter of the adsorbent is smaller than 1 μm or larger than 50 μm, the adsorbent is more frequently dropped, and the acetaldehyde deodorizing performance is lowered.

  In the present invention, the average particle diameter refers to a median diameter (d50) measured using a particle size distribution measuring apparatus by a laser diffraction / scattering method.

In air filter medium (II), the content of aldehyde adsorbent, it in order to obtain easily the air filter medium more pleating is preferably 5 to 25 g / ^{m 2,} is 10 to 15 g / ^{m 2} Is more preferable.

  In the air filter medium (II), examples of the water-soluble binder include polyvinyl alcohol and starch. Examples of the water-dispersible binder include poly (meth) acrylic acid esters, polyvinyl acetate, polyvinyl chloride, styrene-acrylic resin, vinyl chloride-acrylic resin, silicone resin, styrene-butadiene latex, and the like. It is done. The binder is not limited to these.

  In the air filter medium (II), the binder content is easier to pleat and to prevent deformation of the air filter when the pleated air filter is used at high wind speed, The solid content is preferably 10% by mass or more based on the mass. Moreover, in order to obtain a higher dust holding amount and a higher acetaldehyde deodorizing performance, it is preferably 50% by mass or less.

In the air filter medium (II), the basis weight of the nonwoven fabric of the dust collection layer is 10 to 30 g / m ² , more preferably 15 to 25 g / m ² . When the basis weight is less than 10 g / m ² , the collection efficiency decreases. When the basis weight exceeds 30 g / m ² , the pressure loss increases and the dust holding amount decreases.

  In the air filter medium (II), the single plate pressure loss at 5.3 cm / s of the nonwoven fabric of the dust collection layer is 9.5 Pa or less, more preferably 8.0 Pa or less. When the single plate pressure loss of the nonwoven fabric of the dust collection layer is more than 9.5 Pa, the pressure loss of the air filter increases and the dust holding amount decreases.

  In the air filter medium (II), the electret processing method of the nonwoven fabric of the dust collection layer includes electro electret, thermal electret, radio electret, mechano electret, photo electret, magnet electret, etc. The electret processing methods that have been used are mainly electroelectrets and thermal electrets. The material is preferably a polyolefin-based material, and a copolymer mainly composed of polypropylene or propylene is often used. For the purpose of improving heat resistance, for example, a fatty acid salt such as aluminum stearate or calcium palmitate is used. May contain a small amount.

  In the air filter medium (II), the collection efficiency of atmospheric dust having a particle size of 0.3 μm or more and less than 0.5 μm at 5.3 cm / s of the nonwoven fabric of the dust collection layer is 80% or more, more preferably 90%. That's it. When the collection efficiency of the nonwoven fabric of the dust collection layer is less than 80%, the collection efficiency of the air filter is also lowered. The same applies when the electret processing is not performed.

  In the air filter medium (II), as a method of laminating the support layer and the dust collecting layer, partial or whole fusion such as pin sonic method, hot melt spray method or hot melt such as so-called sinter method is used. Examples thereof include a method of bonding by powder laminating or the like, stitching by a stitch bond method or the like, or confounding by a hydroentanglement method such as a needle punch method or a so-called spunlace method, and the like.

  “Wind pressure resistance” will be described with reference to FIGS. 1 and 2. FIG. 1 is a view showing a method for measuring wind pressure resistance, FIG. 1 (A) is a view seen from the side, and FIG. 1 (B) is a view seen from above. In the present invention, the two pedestals 2 are fixed so that the distance L2 is 52 mm, and the non-woven fabric or the filter medium 1 having a long side of 140 mm × short side of 40 mm is placed between the top plates of the two pedestals 2 with the non-woven fabric or The long side direction of the filter medium 1 and the width direction of the pedestal 2 are passed in parallel, the container 3 is suspended from the center line in the long side direction of the nonwoven fabric or the filter medium 1, and as shown in FIG. The weight 4 is gradually added, and “mass of the container 3 + mass of the weight 4” when the container 3 falls is defined as “wind pressure resistance”. As the base 2, a polystyrene box having a width L1 of 57 mm, a depth of more than 40 mm, and a height H of 155 mm was used. The depth of the base 2 may be any length as long as the width of the nonwoven fabric or the filter medium 1 exceeds 40 mm. The container 3 was hung on the center line in the long side direction of the nonwoven fabric or the filter medium 1 using a thread passed through a resin tube (made of straw, polypropylene) 5 having an outer diameter of 4 mm. For the weight 4, a weight for an upper pan balance was used.

  The wind pressure resistance of MD is the wind pressure resistance of the nonwoven fabric or the filter medium 1 whose long side (140 mm) is MD and the short side (40 mm) is CD, and the wind pressure resistance of CD is the short side (140 mm) is CD and short. It is the wind pressure tolerance of the nonwoven fabric or filter medium 1 whose side (40 mm) is MD.

  In addition, in the air filter medium (I), the nonwoven fabric 1 is conveyed by conveyance supports, such as a wire and a felt, at the time of manufacture. The non-woven fabric 1 is arranged so that the surface that does not contact the carrier for support is the “front surface”, the surface that is in contact with the carrier for support is the “back surface”, and the “front surface” is on the top. The nonwoven fabric 1 is arranged so that the “front surface average value” and the “back surface”, which are the average values of the measured values of the wind pressure resistance of 5 or more nonwoven fabrics 1, are on the top. The “back surface average value”, which is the average value of the measured wind pressure resistance, was calculated, and the average value of the “front surface average value” and the “back surface average value” was defined as “wind pressure resistance”.

  In the air filter medium (II), the filter medium 1 is disposed so that the support layer side is the “front side”, the dust collection layer side is the “back side”, and the “front side” is on the top. The filter medium 1 is arranged so that the “front surface average value” and the “back surface”, which are the average values of the measured values of the wind pressure resistance of one or more sheets of filter medium 1, are on top, and the wind pressure resistance of five or more sheets of filter medium 1 The “back surface average value”, which is the average value of the measured values, was calculated, and the average value of the “front surface average value” and the “back surface average value” was defined as “wind pressure resistance”.

  In the air filter medium (I), the wind pressure resistance [unit: g] of the nonwoven fabric is 6.5 g or more in MD of the nonwoven fabric and 4.5 g or more in CD. More preferably, it is 7.0 g or more in the MD of the nonwoven fabric and 4.8 g or more in the CD. When the wind pressure resistance of MD is 6.5 g or more and the wind pressure resistance of CD is 4.5 g or more, the air filter is not easily deformed when the pleated air filter is used at a high wind speed.

  In the air filter medium (I), the method of adjusting the wind pressure resistance of the nonwoven fabric includes a method of adjusting the basis weight and thickness of the nonwoven fabric, a method of changing the material of the fibers constituting the nonwoven fabric, and the fiber diameter of the fibers constituting the nonwoven fabric. And / or a method of adjusting the fiber length, a method of changing the composition of fibers constituting the nonwoven fabric, a manufacturing condition for producing the nonwoven fabric (heating temperature, pressure, stretching degree, adhesive or binder fiber melting or softening temperature, adhesion And the like, and the like, and the like can be selected appropriately from these methods.

  In the air filter medium (II), the wind pressure resistance [unit: g] of the filter medium after lamination is 8 to 33 g, more preferably 10 to 30 g, still more preferably 12 to 20 g in the MD of the filter medium. In CD, it is 6-20g, More preferably, it is 9-17g, More preferably, it is 10-14g. When the wind pressure resistance of MD is less than 8 g and / or the wind pressure resistance of CD is less than 6 g, the air filter may be deformed when the pleated air filter is used at a high wind speed, and the wind pressure resistance of MD is 33 g. When the wind pressure resistance of the super and / or CD is more than 20 g, the pleatability is lowered and the pressure loss is increased.

  In the air filter medium (II), as a method of adjusting the wind pressure resistance of the filter medium, a method of adjusting the basis weight and thickness of the nonwoven fabric of the support layer, a method of changing the material of the fibers constituting the nonwoven fabric, and configuring the nonwoven fabric A method for adjusting the fiber diameter and / or fiber length of the fiber, a method for changing the composition of the fibers constituting the nonwoven fabric, and the production conditions for producing the nonwoven fabric (heating temperature, pressure, stretching degree, melting of the adhesive or binder fiber or And a method of adjusting the softening temperature, the amount of the adhesive or the binder fiber, and the like, and the like can be appropriately selected from these methods.

  In the air filter medium (II), the fiber diameter of the fibers constituting the nonwoven fabric of the support layer is not particularly limited, but is preferably 1 to 10 dtex, more preferably 3 to 7 dtex. The larger the fiber diameter is, the better the wind pressure resistance is. However, since the adsorbent falls off only with thick fibers, thin fibers are also necessary. On the other hand, when the fiber is too thin, the pressure loss may be inferior. Although it does not specifically limit about fiber length, 5-50 mm is preferable, More preferably, it is 15-35 mm. The longer the fiber length, the better the wind pressure resistance. However, the short fiber is necessary because the air permeability is impaired only by the long fiber. When the fiber length is too short, the strength of the nonwoven fabric may be inferior.

  In the air filter medium (II), the composition of the fibers constituting the nonwoven fabric of the support layer is not particularly limited, but preferably contains polyethylene terephthalate fibers. Also, fibers with relatively high rigidity, mainly polyethylene terephthalate fibers (for example, binder fibers having a core-sheath structure, polyvinyl alcohol fibers, glass fibers, metal fibers, alumina fibers, carbon fibers, regenerated cellulose fibers, bamboo pulp) Good wind pressure resistance can also be obtained by partially blending hemp pulp, etc.).

  In the air filter medium (II), the production conditions for producing the nonwoven fabric of the support layer are not particularly limited. For example, the higher the heating temperature and the applied pressure in the drying step, the better the wind pressure resistance. On the other hand, if the heating temperature and the applied pressure are too high, the fibers may be crushed and air permeability may be impaired. The production conditions may be adjusted in a timely manner so that the nonwoven fabric of the present invention can be obtained.

  If necessary, without departing from the spirit of the present invention, deodorization, antibacterial, antifungal, antiviral, antiallergen, insecticide, insecticidal, deodorant, aroma, temperature sensing, heat retention, heat storage, heat storage, heat generation, Various functions such as heat absorption, waterproofing, water resistance, water repellency, hydrophobicity, hydrophilicity, dehumidification, humidity adjustment, moisture absorption, oil repellency, lipophilicity, oil absorption, and transpiration or sustained release of water and volatile chemicals, etc. on nonwoven fabric It may be added.

  In the air filter medium (I), only the non-woven fabric may be used as an air filter medium, or may be laminated with another non-woven fabric as an air filter medium. As a method of laminating the above-mentioned non-woven fabric and another non-woven fabric, it is possible to partially or totally fuse by a pin sonic method, adhesion by a hot melt powder type laminating method such as a hot melt spray method or a so-called sinter method, stitch bond, etc. Examples are a method of integrating by applying tangling by a water tangling method such as a stitching method or a needle punch method or a so-called spunlace method.

  The air filter medium of the present invention is pleated and used as an air filter. The pleating process is a mountain-folded folding process, and is preferable because the area of the air filter medium can be increased with respect to a certain ventilation area. The shape of the pleat is not particularly limited, and may be appropriately selected according to the use of the air filter.

  The air filter medium and the air filter of the present invention are used in various scenes such as general residential use, commercial use, automobiles and railway vehicles, air conditioners, air purifiers, vacuum cleaners, dehumidifiers, dryers, humidifiers. By installing and using in various air treatment devices such as a ventilation fan and a heat exchange device, an air cleaning effect such as dust removal and deodorization can be obtained. Moreover, you may use the air filter medium and air filter of this invention for the external airflow inlet (a vent hole, a window, etc.) for natural air supply / exhaust.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the examples. In the examples, “%” and “part” represent “% by mass” and “part by mass”, respectively, unless otherwise specified.

<Air filter medium (I)>

  The chemical bond nonwoven fabric containing the polyester fiber which has the fabric weight, thickness, and wind pressure resistance described in Table 1 was used as the air filter medium of each Example and each Comparative Example.

  Using the air filter media of each example and each comparative example, the pleats with a folding height of 26 mm are performed, and frame materials are attached to four sides of the filter media for 36 peaks, and the length is 180 mm, the width is 180 mm, the height Air filters of each example and each comparative example having 29 mm and a pleat interval of about 5 mm were produced.

[Evaluation]
About the air filter medium of each Example and each comparative example, as shown below, pressure loss (pressure loss) and pleat workability (folding resistance, folding workability) were evaluated. Moreover, using the produced air filter, the structural durability under high wind speed was evaluated, and the results are shown in Table 2.

(Test 1-1) Measurement of pressure loss According to JIS B 9908, the pressure loss of the air filter medium was measured at a wind speed of 5.3 cm / second, and the result was determined based on the following evaluation criteria.
○: Pressure loss is less than 1.5 Pa Δ: Pressure loss is 1.5 Pa or more and less than 2.0 Pa x: Pressure loss is 2.0 Pa or more In the present invention, Δ or more is regarded as a practical level.

(Test 1-2) Evaluation of pleat workability (folding resistance) Using a pleating machine, air filter media was pleated at a fold mountain height of 26 mm, and air filter media was pleated based on the following criteria. The property (folding resistance) was determined.
○: The filter material after folding is not torn and can be processed without problems. X: The filter material after folding is torn. In the present invention, ○ is set to a practical level.

(Test 1-3) Evaluation of pleat workability (folding workability) In the same manner as test 1-2, the air filter medium 300m was pleated, and the pleatability (folding) of the filter medium based on the following criteria. Sex).
○: No irregularities in height and meandering occur during processing of filter medium 300m, and can be processed without problems. Δ: Unevenness in height and meandering occur at least once and less than 3 times during processing of filter medium 300m. Can be processed without problems x: During the processing of the filter medium 300 m, unevenness in the height and meandering occurred three times or more, and stable pleating cannot be performed. In the present invention, Δ or more was regarded as a practical level.

(Test 1-4) Structural durability evaluation under high wind speed Using a test apparatus according to JIS B 9908, the pleat shape was visually observed through the air filter at a wind speed of 3.0 m / s. The results were judged based on the judgment criteria.
◎: No disturbance in the pleat interval ○: One or more places where the crease interval is less than 3 mm or 7 mm or more is seen △: Three places where the crease interval is less than 3 mm or 7 mm or more More than 6 places are observed x: 6 or more places where the crease interval is less than 3 mm or 7 mm or more are seen.

As is apparent from Table 2, the basis weight is 40 to 100 g / m ² , the thickness is 0.1 to 1.4 mm, the wind pressure resistance of MD of the nonwoven fabric is 6.5 g or more, and the wind pressure resistance of CD is The air filter media of Examples 1-1 to 1-7 and the air filter of Examples 1-1 to 1-7 using the air filter media composed of non-woven fabric having a weight of 4.5 g or more were tested. A practical level of judgment was obtained in any of -1 to 1-4.

On the other hand, although the fabric weight is 40 to 100 g / m ² and the thickness is 0.1 to 1.4 mm, the wind pressure resistance of MD of the nonwoven fabric is less than 6.5 g and / or the wind pressure resistance of CD. In the air filters of Comparative Examples 1-1 to 1-3, which are composed of a nonwoven fabric having a weight of less than 4.5 g, there are many places where the pleat shape is deformed under high wind speed, and the practical level of the present invention has not been reached. It was.

In addition, the air filter medium of Comparative Example 1-4, which is composed of a nonwoven fabric having a basis weight of less than 40 g / m ² and a nonwoven fabric CD having a wind pressure resistance of less than 4.5 g, has a pleat processability (processing resistance and folding processing). In addition, in the air filter of Comparative Example 1-4, there were many places where the pleated shape was deformed under high wind speed, and the practical level of the present invention was not reached.

Moreover, although a fabric weight is more than 100g / m < ² > and thickness is more than 1.4mm, it is comprised with the nonwoven fabric whose wind pressure tolerance of MD of a nonwoven fabric is 6.5 g or more, and the wind pressure tolerance of CD is 4.5 g or more. In the air filter of Comparative Example 1-5, folding workability was poor and the practical level of the present invention was not reached. Moreover, although a fabric weight is more than 100g / m < ² >, thickness is 0.1-1.4mm, the wind pressure tolerance of MD of a nonwoven fabric is 6.5g or more, and the wind pressure tolerance of CD is 4.5g or more. In the air filter of Comparative Example 1-6 composed of a certain nonwoven fabric, the pressure loss was high, the foldability was poor, and the practical level of the present invention was not reached.

《Air filter media (II)》

  A non-woven fabric that has been processed so that the aldehyde adsorbent having the average particle diameter in Table 3 has the adsorbent content and binder content in Table 3 is applied to the non-woven fabric having the constituent fibers, type, basis weight, and thickness described in Table 3. As a support layer, two layers are laminated by a hot melt spray method using a non-woven fabric having the constituent fibers, types, presence or absence of electret processing, basis weight, single plate pressure loss, and collection efficiency described in Table 4 as a dust collection layer. The filter medium having cantilever bending resistance and wind pressure resistance described in 5 was used as the air filter medium of each Example and each Comparative Example. The aldehyde adsorbent used was an aluminum silicate modified with an amino compound, and the binder used was a styrene-acrylic resin emulsion binder. The support layer was prepared by dispersing a binder and an aldehyde adsorbent in water, applying a coating solution prepared by mixing and stirring to a non-woven fabric by size pressing, and drying at 120 ° C.

  Using the air filter media of each example and each comparative example, the pleats with a folding height of 26 mm were performed, and a frame material (polyethylene terephthalate fiber nonwoven fabric) was attached to four sides of the filter media for 36 mountains, and the length was 180 mm. An air filter of each example and each comparative example having a width of 180 mm, a height of 29 mm, and a pleat interval of about 5 mm was produced.

[Evaluation]
The air filter media of each Example and each Comparative Example were evaluated for the adsorbent dropping and folding workability as shown below. Moreover, using the produced air filter, structural durability under high wind speed, pressure loss (pressure loss), collection efficiency, dust retention, acetaldehyde deodorization performance were evaluated, and the results are shown in Table 6.

(Test 2-1) Evaluation of adsorbent dropout Each of the air filter media was cut into a size of 10 cm × 10 cm to make a sample. Place the sample on an A4 size black drawing paper on the test bench, above the sample. A 200 g weight was vertically dropped three times from a height of 5 cm, the amount of the aldehyde adsorbent dropped off on the black drawing paper was visually evaluated, and the folding property of the filter medium was determined based on the following criteria.

A: Adsorbent has not fallen off ○: Adsorbent has dropped off a little ×: Adsorbent has dropped off a lot In the present invention, ○ or more was regarded as a practical level.

(Test 2-2) Evaluation of folding workability (pleating processability) Using a pleating machine, the air filter medium 300m was pleated at a folding height of 26 mm, and the filter medium was folded based on the following criteria. Was judged. In the present invention, Δ or more is regarded as a practical level.

○: No irregularities in height and meandering occur during processing of filter medium 300m, and can be processed without problems. Δ: Unevenness in height and meandering occur at least once and less than 3 times during processing of filter medium 300m. Can be processed without problems. X: Unevenness of mountain height and meandering occurred 3 times or more during the processing of the filter medium 300 m, and stable pleating cannot be performed.

(Test 2-3) Structural durability evaluation under high wind speed Using a test apparatus according to JIS B 9908, the pleat shape was visually observed through the air filter at a wind speed of 3.0 m / s. The results were judged based on the judgment criteria. In this evaluation, Δ or more was regarded as a practical level.

◎: No disturbance in the fold mountain interval is observed ○: One or more places where the fold mountain interval is less than 3 mm or 7 mm or more is seen △: Three places where the fold mountain interval is less than 3 mm or 7 mm or more More than 6 locations can be seen x: 6 or more locations where the crease interval is less than 3 mm or 7 mm or more

(Test 2-4) Measurement of Pressure Loss Using a test apparatus according to JIS B 9908, the pressure loss of the air filter was measured at a wind speed of 2.5 m / s, and the result was determined based on the following evaluation criteria. In the present invention, a value of ○ or more was regarded as a practical level.

A: Pressure loss is less than 65 Pa B: Pressure loss is 65 Pa or more and less than 95 Pa X: Pressure loss is 95 Pa or more

(Test 2-5) Measurement of collection efficiency Air dust having a particle diameter of 0.3 μm or more and less than 0.5 μm when air is passed through an air filter at a wind speed of 1.5 m / s using a test apparatus according to JIS B 9908 The collection efficiency was measured, and the results were determined based on the following evaluation criteria. In the present invention, a value of ○ or more was regarded as a practical level.

◎: Collection efficiency is 95% or more ○: Collection efficiency is 70% or more and less than 95% ×: Collection efficiency is less than 70%

(Test 2-6) Measurement of Dust Holding Amount Using a test apparatus according to JIS B 9908, dust holding amount (Dust Holding Capacity, DHC) was evaluated. While passing through the air filter at a wind speed of 2.5 m / s, the test dust JIS15 species was loaded from the upstream side at a concentration of 70 mg / m ³ , and dust was increased until the initial pressure loss before the dust load increased by 100 Pa. Loaded. The dust mass held by the air filter was measured, the dust holding amount per air filter opening area was calculated, and the result was judged based on the following evaluation criteria. In the present invention, a value of ○ or more was regarded as a practical level.

A: Dust holding amount is 150 g / m ² or more ○: Dust holding amount is 120 g / m ² or more and less than 150 g / m ² ×: Dust holding amount is less than 120 g / m ²

(Test 2-7) Measurement of acetaldehyde deodorization performance An air purifier equipped with an air filter was placed in a 1 m ³ stainless steel box and sealed, and 10 ppm of acetaldehyde gas was injected, and at the same time the wind speed was 1.5 m / s. The air purifier was operated, the acetaldehyde concentration in the box after 30 minutes was measured with a gas detector tube, and the result was judged based on the following evaluation criteria. In the present invention, a value of ○ or more was regarded as a practical level.

A: Acetaldehyde concentration in the box after 30 minutes is less than 1 ppm B: Acetaldehyde concentration in the box after 30 minutes is 1 ppm or more and less than 3 ppm X: Acetaldehyde concentration in the box after 30 minutes is 3 ppm or more

(Test 2-8) Measurement of cantilever bending resistance The 45 ° cantilever bending resistance was measured according to JIS L 1096. The test piece size was 297 mm for the long side and 20 mm for the short side. The MD cantilever bending resistance is that the long side (297 mm) is MD, the support layer side is the “front side”, and the filter media is placed so that the “front side” is on the top. The filter media were arranged so that the “front side average value”, which is the average value of the measured cantilever stiffness, and the “back surface” were on top, and the cantilever stiffness of five or more filter media was measured. The “back surface average value”, which is the average value of the values, was calculated, and the average value of the “front surface average value” and the “back surface average value” was defined as “MD cantilever stiffness”. The cantilever stiffness of the CD was the same as the method for measuring the MD cantilever stiffness, except that the long side (297 mm) was CD. From the results of cantilever bending resistance in Table 5 and the folding workability results in Table 6, it can be said that folding workability cannot be evaluated with cantilever bending resistance.

As is clear from Table 6, the support layer is 40 to 100 g / m ² in basis weight and 0.2 to 1.4 mm in thickness of non-woven fabric having an average particle diameter of 1 to 50 μm. The agent is a nonwoven fabric supported by a binder, the dust collection layer is electret processed, the basis weight is 10 to 30 g / m ² , the single plate pressure loss at 5.3 cm / s is 9.5 Pa or less, and 5.3 cm The non-woven fabric has an air dust collection efficiency of 80% or more when the particle size is 0.3 μm or more and less than 0.5 μm at / s, and the wind pressure resistance of MD of the filter medium in which the support layer and the dust collection layer are laminated is 8 The air filter of Examples 2-1 to 2-20 using Example 2-1 to 2-20 air filter medium and the air filter medium having a wind pressure resistance of CD of 6 to 20 g, Practical level in any of tests 2-1 to 2-7 Is the judgment was obtained.

In contrast, the air filter medium of Comparative Example 2-1 in which the basis weight of the nonwoven fabric of the support layer is less than 40 g / m ² , the thickness is less than 0.2 mm, and the wind pressure resistance of CD of the laminated filter medium is less than 6 g. Folding workability was bad. Further, in the air filter of Comparative Example 2-1, there were many places where the pleated shape was deformed under high wind speed, and the practical level of the present invention was not reached.

Moreover, the air filter medium of Comparative Example 2-2, in which the basis weight of the nonwoven fabric of the support layer was over 100 g / m ² and the wind pressure resistance of CD of the laminated filter medium was over 20 g, had poor foldability. Moreover, in the air filter of Comparative Example 2-2, the pressure loss was high, the dust holding amount was low, and the practical level of the present invention was not reached.

  In addition, the air filter medium of Comparative Example 2-3 in which the thickness of the nonwoven fabric of the support layer was more than 1.4 mm had poor foldability and did not reach the practical level of the present invention.

  In addition, the air filter medium of Comparative Example 2-4, in which the average particle size of the aldehyde adsorbent is less than 1 μm, often drops off the aldehyde adsorbent, and the air filter of Comparative Example 2-4 has poor acetaldehyde deodorization performance. The practical level of the present invention was not reached.

  In addition, the air filter medium of Comparative Example 2-5 in which the average particle diameter of the aldehyde adsorbent is more than 50 μm is often dropped of the aldehyde adsorbent, and the air filter of Comparative Example 2-5 has poor acetaldehyde deodorization performance. The practical level of the present invention was not reached.

  Further, the air filter of Comparative Example 2-6, in which the non-woven fabric of the dust collection layer was not electret processed and the collection efficiency was less than 80%, had a low collection efficiency and did not reach the practical level of the present invention.

Further, the air filter of Comparative Example 2-7, in which the basis weight of the nonwoven fabric of the dust collection layer is less than 10 g / m ² and the collection efficiency is less than 80%, the collection efficiency is low, and the practical level of the present invention has not been reached. It was.

Moreover, in the air filter of Comparative Example 2-8 in which the basis weight of the nonwoven fabric of the dust collection layer is more than 30 g / m ² and the single plate pressure loss is more than 9.5 Pa, the pressure loss is high and the dust holding amount is low. The practical level was not reached.

  Further, in the air filter of Comparative Example 2-9 in which the wind pressure resistance of MD of the filter medium is less than 8 g and the wind pressure resistance of CD is less than 6 g, the pleat shape is deformed at a high wind speed, and the dust holding amount is low. The practical level of the present invention was not reached.

  Further, the air filter medium of Comparative Example 2-10, in which the filter medium had a wind pressure resistance of MD of more than 33 g and the CD had a wind pressure resistance of more than 20 g, had poor folding workability. Further, the air filter of Comparative Example 2-10 had high pressure loss, and did not reach the practical level of the present invention.

From the results of Examples 2-1 and 2-10 to 2-13, the air filter media of Examples 2-1 and 2-11 and 2-12 in which the content of the aldehyde adsorbent is 5 to 25 g / m ² was obtained. The folding workability was better. Moreover, from the results of Examples 2-1 and 2-14 to 2-17, Examples 2-1 to 2-15 and 2-16 in which the binder content is 10 to 50% by mass with respect to the aldehyde adsorbent. The air filter medium had a higher dust retention.

  From the results of Examples 2-1 and 2-18, the air filter medium of Example 2-1 in which the fiber constituting the support layer is a polyethylene terephthalate fiber has better folding workability, and the pleats under high wind speed. There was no disturbance in the interval, and the structural durability was good. Moreover, from the results of Examples 2-1, 2-19, and 2-20, the nonwoven fabric constituting the support layer was a chemical bond nonwoven fabric or a thermal bond nonwoven fabric. The folding workability was better.

  The air filter medium and the air filter of the present invention are used in various scenes such as general residential use, commercial use, automobiles and railway vehicles, air conditioners, air purifiers, vacuum cleaners, dehumidifiers, dryers, humidifiers. It can be used for various air treatment devices such as ventilation fans and heat exchange devices. It can also be used for an external air flow inlet (such as a vent or a window) for natural supply and exhaust.

1 Nonwoven fabric or filter medium 2 Base 3 Container 4 Weight 5 Resin tube

Claims (5)

The basis weight is 40 to 100 g / m ² , the thickness is 0.1 to 1.4 mm, and the wind pressure resistance [unit: g] defined below is 6.5 g or more in the MD of the nonwoven fabric, and 4 in the CD. An air filter medium comprising a non-woven fabric of 5 g or more.
Wind pressure resistance: Two pedestals (57 mm wide x 40 mm deep x 155 mm high, made of polystyrene) are fixed at a distance of 52 mm, and a non-woven fabric having a long side of 140 mm and a short side of 40 mm is placed between the top plates of the two pedestals. The long side direction and the width direction of the pedestal are passed in parallel, the container is suspended from the center line in the long side direction of the nonwoven fabric, the weight is gradually added to the container, and the "mass of the container at the time the container falls + Mass of weight is defined as “wind pressure resistance”. An air filter medium composed of two layers, a support layer and a dust collection layer,
The support layer has a basis weight of 40 to 100 g / m ² and a non-woven fabric having a thickness of 0.2 to 1.4 mm, and an aldehyde adsorbent that is particles having an average particle diameter of 1 to 50 μm is supported by a binder. Non-woven,
The dust collection layer is electret processed, has a basis weight of 10 to 30 g / m ² , a single plate pressure loss at 5.3 cm / s is 9.5 Pa or less, and a particle diameter at 5.3 cm / s is 0.3 μm or more. It is a non-woven fabric with an air dust collection efficiency of less than 0.5 μm and 80% or more,
An air filter medium characterized in that the air pressure resistance [unit: g] defined below is 8 to 33 g in MD of the air filter medium and 6 to 20 g in CD.
Wind pressure resistance: Two pedestals (width 57mm x depth 40mm x height 155mm, made of polystyrene) are fixed at a distance of 52mm, and air filter media with a long side 140mm x short side 40mm is mounted on the top plate of the two pedestals The long side direction and the width direction of the pedestal are passed in parallel, the container is suspended from the center line of the long side direction of the air filter medium, weights are gradually added to the container, and the container is dropped “Mass of container + mass of weight” is defined as “wind pressure resistance”. The air filter medium according to claim ² , wherein the content of the aldehyde adsorbent is 5 to 25 g / m2, and the content of the binder is 10 to 50 mass% with respect to the aldehyde adsorbent.   The air filter medium according to claim 2 or 3, wherein the support layer is a chemical bond nonwoven fabric containing polyethylene terephthalate fibers or a thermal bond nonwoven fabric containing polyethylene terephthalate fibers.   An air filter using the air filter medium according to claim 1.