JP2013052369A - Filter medium for air filter, and air filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the deformation of a filter because of excelling in water permeability while exhibiting antimicrobial, mildewproofing, deodorizing and flame resisting performance even after submerged regarding the filter usable in a place where rainwater infiltrates simultaneously with the introduction of outside air like a cabin filter.SOLUTION: This filter medium for the air filter supports a deodorant between a thermobonded nonwoven fabric and an air permeable nonwoven fabric through heat-adhesive resin. In the filter medium, the weight ratio of heat-fusion fiber to non-heat-fusion fiber in the thermobonded nonwoven fabric is in a range of 40:60 to 100:0, and a water-insoluble flame retardant, and one or both of a water-insoluble antibacterial agent and an antimicrobial agent are supported to the thermobonded nonwoven fabric through binder resin.

Description

  The present invention relates to a filter medium suitably used for an air filter, particularly a cabin filter, a method for producing the same, and an air filter.

  A filter used in a place where rainwater enters simultaneously with the introduction of outside air, such as a cabin filter attached to an air conditioner of an automobile, is easily deformed due to the influence of the entering water. Therefore, in order to prevent a load on the air conditioning system, a filter medium having a low water permeability and a good water permeability is required. So far, non-woven fabrics, etc., in which short fibers are resin-processed and hardened are widely used in that the rigidity necessary for maintaining the filter shape and suppressing an increase in pressure loss due to shape change is high. However, these non-woven fabrics are easily flammable because the main component is an organic substance, and are required to be flame retardant from the viewpoint of preventing fire in the automobile interior.

  Examples of the filter media that impart flame retardancy include organic flame retardants such as organic bromine compounds, organic chlorine compounds, and organic phosphorus compounds, and inorganic flame retardants such as antimony compounds and metal hydroxides. Patent Document 1 proposes a technique for applying a non-halogen flame retardant, a phosphorus flame retardant, or the like to a filter using a binder due to an increase in environmental orientation.

  On the other hand, filters used for air purification applications are required to have antibacterial, antifungal and deodorizing properties in accordance with recent market trends for improving the living environment. Patent Document 2 proposes a filter medium in which granular activated carbon is sandwiched between two breathable nonwoven fabrics, and various antibacterial agents and fungicides are added to the breathable nonwoven fabric.

  These filter media exhibit various functions such as antibacterial properties, antifungal properties, deodorization properties, and flame retardance before water is loaded, but in filters such as cabin filters used in situations where water is loaded. However, there are problems such as elution into the water loaded with various functional drugs and insufficient function, or the outflow of functional chemicals entering the deodorant and forming a film, resulting in a significant decrease in deodorization performance. It was.

  For such problems, Patent Document 3 discloses a technique in which a water repellent is attached to a nonwoven fabric in order to suppress the outflow of various functional agents when wet. However, the water repellent covers the functional agent. However, there still remains a problem that the conventional functions are not fully exhibited.

JP 2009-178669 A JP 2000-70646 A JP 2006-159133 A

  The present invention is a filter that can be used in a place where rainwater enters like a cabin filter in order to solve the above problems, and exhibits high antibacterial performance, antifungal performance, and flame retardancy even after being exposed to water. Therefore, an object of the present invention is to provide a filter material for an air filter and an air filter that are capable of suppressing the increase in pressure loss and are not easily deformed.

In order to solve the above problems, the present invention has the following configuration.
(1) A filter medium for an air filter in which a deodorizer is supported between a thermal bond nonwoven fabric and a breathable nonwoven fabric via a thermal adhesive resin, wherein the thermal bond nonwoven fabric is a thermal fusion fiber and a non-thermal fusion fiber. In a range of 40:60 to 100: 0 by mass ratio, a water-insoluble flame retardant and either or both of a water-insoluble antibacterial agent and a fungicide are bonded via the resin binder. A filter medium for an air filter, which is carried on a nonwoven fabric, and the amount of the resin binder attached is 3% by mass to 15% by mass with respect to the thermal bond nonwoven fabric,
(2) The air filter medium, wherein the resin binder is a polyester binder,
(3) The air filter medium according to any one of the above, wherein the water-insoluble flame retardant is melamine polyphosphate,
(4) The air filter medium according to any one of the above, wherein the water-insoluble antibacterial and antifungal agent is selected from a benzimidazole compound and zinc pyrithione,
(5) The heat-bonding fiber of the thermal bond nonwoven fabric has a core-sheath structure, and the melting point of the sheath part is 140 ° C. to 200 ° C.
(6) The air filter nonwoven fabric according to any one of the above, wherein the thermal bond nonwoven fabric has a basis weight of 15 to 60 g / m ² .
(7) The air filter medium according to any one of the above, wherein the thermal adhesive resin is selected from at least a polyester resin or a polyethylene resin,
(8) The air filter medium according to any one of the above, wherein the breathable nonwoven fabric is a thermal bond nonwoven fabric or a spunbond nonwoven fabric made of polyester fiber,
(9) An air filter characterized by using any one of the air filter media,
(10) After fixing a water-insoluble flame retardant and any one or both of a water-insoluble antibacterial agent and fungicide to a thermal bond nonwoven fabric by a heat treatment through a resin binder, the thermal bond nonwoven fabric and the breathable nonwoven fabric A method for producing an air filter medium according to any one of the above, characterized in that a deodorizing agent and a thermal adhesive resin are dispersed in between and integrated by thermocompression bonding,
(11) After fixing a water-insoluble flame retardant and a water-insoluble antibacterial and / or anti-mold agent between the breathable nonwoven fabrics by heat treatment through a resin binder, the thermal bond nonwoven fabric and the breathable properties A method for producing an air filter medium according to any one of the above, wherein a deodorizing agent and a thermal adhesive resin are dispersed between the nonwoven fabrics and integrated by thermocompression bonding.

  The filter medium for an air filter according to the present invention can exhibit sufficient antibacterial properties, antifungal properties, flame retardancy, and deodorizing properties even after being exposed to water, can suppress a decrease in rigidity after being exposed to water, and is excellent in water permeability. An increase in pressure loss can be prevented and filter deformation can be suppressed.

  The filter medium for an air filter according to the present invention includes a thermal bond nonwoven fabric containing a heat-bonding fiber and a non-heat-bonding fiber in a mass ratio of 40:60 to 100: 0, a water-insoluble flame retardant, and a water-insoluble solution. One or both of an antibacterial agent and an antifungal agent are supported on the thermal bond nonwoven fabric via a resin binder, and the amount of the resin binder attached is 3% by mass to 15% by mass with respect to the thermal bond nonwoven fabric. It is important to be mass%.

  By taking such a configuration, the following effects can be exhibited. Various water-insoluble, such as water-insoluble flame retardants and water-insoluble antibacterial and anti-fungal agents, in order to demonstrate antibacterial, antifungal, and flame retardant performance over a long period of time even in environments where water is assumed When a functional functional agent is to be attached to a non-woven fabric with a resin binder, various water-insoluble agents are often in the form of fine powders, so that a large amount of resin binder is required to prevent dust generation. As a result, problems such as the incombustibility of the resin binder fail to reach flame retardancy, or functional particles are coated on the resin binder and various functions are not exhibited.

  Therefore, in the present invention, attention was first paid to the amount of the resin binder attached and the mass ratio of the heat-sealing fiber and the non-heat-sealing fiber. By dispersing the amount of the resin binder defined in the present invention in a solvent such as water and dipping, functional particles can be attached to the thermal bond nonwoven fabric through a small amount of resin binder. At the time of dip soaking, resin binders and the like tend to gather at the fiber intersections in the nonwoven fabric, and there are concerns about the occurrence of dust generation at locations where the amount of the resin binder other than the fiber intersections is small, thereby reducing the performance of various functions. Therefore, by applying heat in the drying process and partially melting the heat-fusion fiber, various functional particles are supported on the heat-fusion fiber and the resin binder. Here, the fusion of the heat-fusible fiber is different from the case where the functional particles are adhered while being coated with the resin binder, and the fiber surface is melted so that the functional agent partially adheres to the fiber surface. Therefore, it can be carried without impairing the effects of various functional drugs.

  In addition, various functional agents are fixed in a state where they are adequately coated even when exposed to water as expected in a cabin filter, and since they do not elute in large quantities into water, deodorizers sandwiched between nonwoven fabrics It becomes possible to suppress performance degradation.

  First, the thermal bond nonwoven fabric will be described. First, in order to firmly fix various functional agents such as a flame retardant, the mass ratio of the heat-bonded fiber and the non-heat-bonded fiber in the thermal bond nonwoven fabric is important. In this invention, it discovered that it functions as a filter medium for this purpose by setting this mass ratio to 40: 60-100: 0.

  When the mass ratio of the heat-fusible fiber is less than 40% by mass, the functional drug such as a flame retardant adheres to the non-woven fabric only by the binder resin. Not only does it become difficult, but the air filter medium becomes too soft, and it is difficult to obtain the rigidity required for air filter applications.

  The preferred fiber diameter used for the thermal bond nonwoven fabric is 1.7 dtex as the lower value for both the heat-bonded fiber and the non-heat-bonded fiber, and further 2.0 dtex, while the upper value is 25 dtex or less. Furthermore, it is 15 dtex or less. If the fineness is too small, the density of the nonwoven fabric increases, pressure loss increases, and the dust life tends to be shortened. On the other hand, when the fineness is too large, not only the voids become large and the deodorizing agent tends to fall off, but also the repulsion property becomes strong when the filter is pleated, and the workability tends to be lowered.

  The heat-sealing fiber in the thermal bond nonwoven fabric is preferably a core-sheath type composite fiber having a low melting point component as a sheath and a high melting point component as a core, and examples thereof include a concentric circle type and an eccentric type.

  The mass ratio of the low melting point component and the high melting point component in the heat-sealing fiber is preferably 35:75 to 80:20. If the mass ratio of the low melting point component is too low, the intended effect of the present invention cannot be obtained sufficiently. On the other hand, if the mass ratio of the low-melting point component is too large, a functional agent such as a flame retardant tends to be buried in the melted part, making it difficult to exhibit the function.

  When the heat-fusible fiber is a core-sheath type composite fiber, the composition of the core component is not particularly limited. For example, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, nylon 6, nylon 66 Polyamide resins such as polypropylene, polyethylene and the like can be mentioned, but polyester resins are preferred from the viewpoint of flame retardancy and pleated shape retention, among which polyethylene terephthalate is more preferred, polyethylene terephthalate The melting point of is preferably 260 ° C.

  The composition of the sheath component of the heat-sealing fiber is preferably a copolyester obtained by polycondensation of a dibasic acid and a diol. Specific examples of other copolymerization components based on terephthalic acid and diethylene glycol include isophthalic acid, adipic acid, sebacic acid, diethylene glycol, butanediol, hexanediol, and polyethylene glycol. The melting point depends on the combination and copolymerization ratio. Can be adjusted.

  The melting point of the sheath component of the heat-sealing fiber is preferably 140 ° C to 200 ° C. If the melting point of the sheath component of the heat-sealable fiber is too low, the functional agent such as a flame retardant is impregnated into the thermal bond nonwoven fabric, and then the sheath component is too melted in the hot air drying process, so that the functional agent is buried and functions It becomes difficult to express. On the other hand, when the melting point is too high, melting of the sheath component in the thermal bond nonwoven fabric is difficult to occur, and the functional agent cannot be fixed. As a result, functional chemicals are eluted after being exposed to water, and various functions tend to decrease.

  Here, the melting point refers to the temperature indicating the peak position of the endothermic peak when DSC measurement is performed at a temperature elevation rate of 20 ° C./min using a differential scanning calorimeter. Since the melting start temperature of the heat-sealable fiber is lower than the melting point, the melting of the heat-sealable fiber has started even below the melting point.

  Examples of the non-heat-bonding fiber component include polyester resins such as polyethylene terephthalate, potylene butterene terephthalate, polyethylene naphthalate, and polyethylene naphthalate. Among these, polyethylene terephthalate is preferable from the viewpoint of shape retention. Further, the melting point of the non-heat-bonding fiber is preferably the same temperature as the melting point of the core component of the heat-bonding fiber, and is preferably 260 ° C., for example.

  As described above, in the present invention, the adhesion amount of the resin binder is 3% by mass to 15% by mass with respect to the thermal bond nonwoven fabric. Preferably it is 5 mass% or more. Preferably it is 10 mass% or less. If the amount is too small, the functional agent cannot be sufficiently loaded, while if too much, the functional agent tends to be coated. An appropriate amount is selected as the resin binder, and the supporting of the functional agent is aided by the heat-sealing fiber.

The preferred basis weight of the thermal bond nonwoven fabric used in the present invention is 15 to 70 g / m ² . If the basis weight is too small, not only the form of the nonwoven fabric cannot be maintained, but also the deodorant tends to fall off. Conversely, if the basis weight is too large, the pressure loss of the nonwoven fabric tends to increase.
The thickness of the thermal bond nonwoven fabric is preferably 0.15 to 0.40 mm. If the thickness is less than 0.15 mm, the fiber density becomes too high, the pressure loss is increased, and the dust retention is reduced, which is not preferable. On the other hand, if the thickness exceeds 0.40 mm, the fusion between the fibers is weakened, and the strength as a nonwoven fabric cannot be obtained sufficiently.

  The air filter medium used in the present invention is characterized in that a flame retardant is attached to a thermal bond nonwoven fabric, but the flame retardant is preferably water-insoluble. Because the flame retardant is water-insoluble, it prevents the flame retardant from degrading due to the leaching of the flame retardant into the water and detachment from the filter even in the environment where water is expected, such as in cabin filters. Is possible. Here, water-insoluble can be defined as one that dissolves 1% by mass or less (1 g / 100 g of water) in neutral water at 25 ° C.

  The water-insoluble flame retardant used in the present invention is preferably a phosphorus-based flame retardant in consideration of the environment, and specific examples include phosphate esters and melamine phosphate. These phosphorus flame retardants may be used alone or in admixture of two or more.

  The water-insoluble flame retardant used in the present invention is preferably 10% by mass to 30% by mass with respect to the thermal bond nonwoven fabric. If the content of the flame retardant is low, sufficient flame retardancy cannot be obtained. On the other hand, if it is high, clogging is likely to occur, the pressure loss of the filter medium increases, and the dust retention decreases, which is not preferable.

  In the air filter medium used in the present invention, either or both of a water-insoluble antibacterial agent and an antifungal agent are supported on a thermal bond nonwoven fabric. The antibacterial and antifungal agents are insoluble in water, so that the antibacterial and antifungal agents elute in water even under an environment where water is expected, such as in cabin filters, resulting in a decrease in antibacterial and antifungal performance. Can be prevented. Here, water-insoluble can be defined as 1% by mass or less (1 g / 100 g of water) with respect to neutral water at 25 ° C.

  The water-insoluble antibacterial and antifungal agent used in the present invention is preferably an organic compound containing at least one of a nitrogen-containing heterocyclic ring and a sulfur atom and a particulate material. Specific examples include organic antibacterial and antifungal agents such as benzimidazole compounds, pyrithione compounds, and isothiazoline compounds. Among these, combinations of pyrithione compounds and benzimidazole compounds are preferable. By adopting this combination formulation, it is also possible to develop antiviral performance.

The adhesion amount of the water-insoluble antibacterial agent and fungicide used in the present invention is preferably 0.1% by mass to 5.0% by mass with respect to the mass of the thermal bond nonwoven fabric. It can exhibit sufficient antibacterial, antifungal, and antiviral properties by setting a certain amount or more, but if it is too much, the antibacterial and antifungal agents tend not to be sufficiently fixed to the thermal bond nonwoven fabric. It is.
The breathable nonwoven fabric used in the present invention is preferably a hydrophilic nonwoven fabric. Here, the hydrophilic nonwoven fabric refers to a nonwoven fabric having a water resistance of 300 mm or less according to JIS L1092 (2009) A method. As a method for producing a hydrophilic nonwoven fabric, a spunbond nonwoven fabric, a thermal bond nonwoven fabric, a resin bond dry nonwoven fabric, a wet papermaking nonwoven fabric, a needle punched nonwoven fabric, a spunlace nonwoven fabric, a water jet punched dry nonwoven fabric, and an airlaid nonwoven fabric can be used. In consideration of the strength after exposure to water, a spunbond dry nonwoven fabric or a thermal bond nonwoven fabric is preferably used. Moreover, in order to improve water permeability, these nonwoven fabrics may be subjected to a hydrophilic treatment as necessary.

It is preferred that the basis weight of the breathable nonwoven fabric is ^{15g / m 2 ~60g / m 2} . When the basis weight is small, not only the form of the nonwoven fabric cannot be maintained, but also the deodorant tends to fall off. Conversely, when the basis weight increases, the pressure loss of the nonwoven fabric increases, and the water resistance increases and the water permeability tends to decrease.

  Examples of fibers constituting these breathable nonwoven fabrics include fibers using a thermoplastic resin such as polyethylene, polypropylene, and polyester alone, or composite fibers using a plurality of these resins. From the viewpoint of properties, polyester is preferred. The polyester fiber may be either a single polyester fiber, a composite of other fibers and polyester fibers, or a fiber having a core-sheath structure in which the polyester fibers protrude on the sheath side. In addition, hydrophilic fibers such as rayon, cotton, lyocell, tencel, acetate, and natural pulp, particularly cellulosic fibers, can also be present in these nonwoven fabrics in order to increase water permeability.

  It is important for the filter medium for an air filter of the present invention to carry a deodorizer between a thermal bond nonwoven fabric and a breathable nonwoven fabric via a thermal adhesive resin.

Examples of the deodorizer employed in the present invention include activated carbon, zeolite, porous silica, activated alumina and the like, and can be selected from these according to the purpose.
The particle size of the deodorizer employed in the present invention is preferably 90% by mass or more of the deodorizer in the range of 100 μm to 500 μm.

  The fixing method is preferably a method in which a mixed powder of a deodorizing agent and a thermal adhesive resin is sprayed on a thermal bond nonwoven fabric or a breathable nonwoven fabric, and then the other nonwoven fabric is superposed and heat-pressed for integration.

  The thermal adhesive resin that fixes the deodorizer to the thermal bond nonwoven fabric or the breathable nonwoven fabric is a resin that is thermally bonded to the thermal bond nonwoven fabric or the breathable nonwoven fabric. For example, EVA resin, polyester, polyamide, nylon, low Density polyethylene and copolymers thereof, and resin compositions containing these can be used. When the thermal bond nonwoven fabric or breathable nonwoven fabric is polyester, the thermal adhesive resin is polyester, EVA resin, or low density polyethylene. It is more preferable because the adhesiveness is improved, and it may be used alone or in admixture of two or more.

  The preferred range of the particle size of the thermal adhesive resin is 50 μm or more, further 100 μm or more, on the other hand, 1000 μm or less, and further 800 μm or less. By making it more than a specific amount, it is possible to prevent the thermal bond nonwoven fabric or breathable nonwoven fabric from falling off and to prevent scattering. It can prevent that the surface smoothness after fixing to a thermal bond nonwoven fabric or a breathable nonwoven fabric falls by setting it as the amount below a specific.

  The binder resin to be used can be appropriately selected and used, such as acrylic resin, styrene-acrylic copolymer resin, urethane resin, polyester resin, etc., but polyester resin from the viewpoint of flame retardancy and functional drug expression Is preferred.

Adhesion amount of the binder resin to the mass of the thermal bond nonwoven fabric, is preferably 3 mass% to 1 0% by weight. If the amount of binder resin attached is too low, the amount required to attach a functional agent such as a flame retardant to the thermal bond nonwoven fabric cannot be secured, before the solvent enters the hot air drying process and the heat-fusible fiber melts. It is not preferable because it will fall off from the fiber. On the other hand, if the adhesion amount is too large, the flame retardant performance is lowered, and the functional agent is covered with a binder resin, so that the function is hardly exhibited.

  Next, the example of the manufacturing method of the filter material for air filters of this invention is demonstrated. A flame retardant, a water-insoluble antibacterial agent and / or antifungal agent, and a binder resin are mixed in a water-based solvent in the same bath to obtain a processing liquid. The working liquid is impregnated into the thermal bond nonwoven fabric and then dried to remove the solvent. And it can fix by heat-processing and a heat-fusion fiber fuse | melting. In this step, added value to the filter medium can be added by adding a functional agent such as a water repellent, a fragrance, a colorant, and a deodorant to the aqueous solvent.

  Examples of the method for drying the thermal bond nonwoven fabric coated with the working fluid include a hot air drying method and a Yankee drum method, but a hot air drying method that is less likely to cause migration such as a flame retardant, an antibacterial agent, and an antifungal agent is preferably employed. . The drying temperature is preferably 100 ° C to 190 ° C. If the temperature is low, drying tends to be insufficient. If the temperature is too high, the heat-bonding fiber of the thermal bond nonwoven fabric will melt excessively, and the flame retardant, antibacterial agent, and fungicide will be buried in the fiber. There is a tendency not to be effective.

  Next, the integration process of the thermal bond nonwoven fabric, the deodorant and the breathable nonwoven fabric will be described in detail. First, a sufficiently mixed and stirred deodorant and thermal adhesive resin are sprayed on the thermal bond nonwoven fabric, and heat treated to melt the thermal adhesive resin. A heating furnace can be used as a heating method. As for temperature, the temperature in a heating furnace has preferable 130 to 160 degreeC. The heat treated material can be covered with a breathable nonwoven fabric and pressed to be integrated. A cold roll can be used for pressurization. On the contrary, thermal adhesive resin may be sprayed and heat-treated on the breathable nonwoven fabric to melt the thermal adhesive resin, and the thermal bond nonwoven fabric may be covered and pressed to be integrated.

  Moreover, it is preferable that the bending resistance of the filter medium for an air filter of the present invention according to JIS L1096 Gurley method is 350 mg or more. When the bending resistance is 350 mg or more, sufficient filter dimensional stability is obtained, and the increase in structural pressure loss caused by deformation is suppressed without deformation even under the high airflow used in cabin filters. Can do.

  The filter of the present invention may use the laminated filter media as they are, but in order to put more filter media in a limited size, it is preferable to increase the filter media area by applying a mountain-shaped folding process called pleating. .

  As a pleating method, there are a reciprocating method, a rotary method, and the like, and any method may be used as long as it is a method of processing in a mountain-valley shape. Further, in order to maintain the pleat shape, ribbon processing may be applied to the downstream layer with respect to the air inflow direction.

  Hereinafter, the present invention will be described in detail based on examples, but the present invention is not necessarily limited thereto.

The following methods are used for measurement of the basis weight, pressure loss, flame retardancy, antibacterial property, antifungal property, antiviral property, solubility, deodorizing performance, water resistance, filter deformation, and water load test in this example.
(1) <Unit weight>
Let stand at room temperature of 23 ° C. and 50% RH for 8 hours or longer to obtain the mass of the evaluation sample (thermal bond nonwoven fabric, breathable nonwoven fabric, filter medium), and then change the mass per 1 m 2 from the area to the basis weight of each evaluation sample Asking. The minimum sampling area is 0.01 m 2 or more.
(2) <Pressure loss>
A flat air filter medium was attached to an experimental duct, and air having a temperature of 23 ° C. and a humidity of 50% RH was blown into the duct at a speed of 0.1 m / sec. The differential pressure between the upstream side and the downstream side of the air filter medium at that time was measured with a digital manometer MA2-04P manufactured by MODUS.
(3) <Flame retardance>
Carried out from both sides of the filter medium for air filter according to FMVSS 302 method, “self-extinguishing” when not reaching the marked line A, “◯” when the burning speed is within 100 m / min beyond the marked line A, marked The case where the burning rate was 100 m / min or more beyond the line A was defined as “x”.
(4) <Antimicrobial test>
According to JIS L1902 (2008) (antibacterial test of fiber products, quantitative test (bacterial solution absorption method)), Staphylococcus aureus was used as the bacterial species and bacteriostatic activity value of 2.0 or more was regarded as having antibacterial properties.
(5) <Anti-mold test>
In JIS Z2911 (2010) (mold resistance test (wet method)), a sample or test piece inoculated with no growth of mycelium (indicated by 0) was regarded as having antifungal properties.
(6) <Antiviral test>
Antiviral evaluation was performed according to JIS Z2801 (antibacterial processed product-antibacterial test method / antibacterial effect).

  The test conditions adopted are as follows.

・ Bacteria: Influenza A virus (H1N1)
-Bacterial solution conditions: Amount of virus acting 0.2 mL
-Action condition: 25 ° C for 24 hours-Effect determination: When the virus infection titer was 10% or less of the initial value, it was determined as "effective", and when it exceeded 10%, it was determined as "no effect".
(7) <Deodorization performance evaluation>
A plate-shaped filter medium preheated in a drying cabinet at 120 ° C. for 2 hours was attached to the experimental column, and air at a temperature of 23 ° C. and a humidity of 50% RH was blown through the column at a speed of 0.1 m / sec. Further, from the upstream side, toluene is volatilized by a permeator and added so that the upstream concentration becomes 80 ppm. Air is sampled on the upstream side and downstream side of the filter medium, and each toluene concentration is measured using an infrared absorption type continuous monitor. Was measured over time, and the removal efficiency was calculated by the following equation.
Removal efficiency (%) = [(C ₀ −C) / C ₀ ] × 100
Where C ₀ : upstream toluene concentration (= 80 ppm)
C: Toluene concentration on the downstream side (ppm)
The removal efficiency 3 minutes after the start of the addition of toluene was defined as the initial removal efficiency, and the initial removal efficiency was compared.
(8) <Water resistance of nonwoven fabric>
The water resistance was measured according to Method A (low water pressure method) described in JIS L1092. Five test pieces of 150 mm x 150 mm are collected, attached to the water resistance test equipment so that the test pieces touch water, the water level is raised at a speed of 100 mm / min, and water comes out from three places downstream of the test piece. The water level was measured in mm. The measurement was performed 5 times, and the average value was taken as the measurement value.

(9) <Solubility measurement>
When the target compound is in the form of a lump, it is finely pulverized in advance with a mortar to make the particle size 100 μm or less. 100 g of pure water is prepared and dissolved while stirring until the target compound is saturated while keeping the water temperature at a constant temperature of 25 ° C. The portion insoluble in water is removed by filtration, and the filtrate is distilled off under reduced pressure. The obtained product was completely heat-dried at 100 ° C., and the weight was measured. Next, the solubility was calculated by the following formula.

  Solubility (wt%) = (A (g) / 100 (g) water) × 100.

(10) <Filter deformation>
The filter material for an air filter according to the present invention is pleated and framed so as to be 43 in a size of width 200 mm × depth 250 mm × height 20 mm. The solution was dropped while allowing a flow rate of 300 m <3> / h to pass through at a dropping speed, and the filter deformation was visually confirmed. A filter medium that was not deformed at all was indicated by “◯”, a filter medium that was slightly deformed by a distortion, “△”, and a filter medium that was largely deformed and could be detached from the flange was indicated by “X”.

(11) <Water load test method>
A sample for measurement of 15 cm × 15 cm was taken and held in a duct of 10 cm × 10 cm so as to be horizontal with respect to the ground, while air of a wind speed of 0.75 m / sec was vented, and 600 cc from 30 cm above the sample position. The distilled water was uniformly added dropwise to the filter medium with a dropper at a rate of 30.0 cc / min.

[Example 1]
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 40g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 100: 0
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ Composition of core part of heat-sealing fiber: Polyester Melting point of sheath part of heat-sealing fiber: 180 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
(Breathable nonwoven fabric)
A thermal bond nonwoven fabric made of polyester with a basis weight of 40 g / m 2 and a water resistance of 120 mm was used.
(Flame retardance)
Melamine phosphate (manufactured by Sanwa Chemical Co., Ltd.) having a solubility in water of 0.68% was used.
(Antimicrobial agent)
Zinc pyrithione (trade name: MRT-100 (manufactured by Osaka Kasei Co., Ltd.)) having a solubility in water of 0.08% was used.
(Anti-mold agent)
Thiabendazole having a water solubility of 0.05% was used.
(Resin binder)
As the resin binder, an ester binder (trade name: Casezole (registered trademark) ES-7 (manufactured by Nikka Chemical Co., Ltd.)) was used.
(Deodorant)
Coconut shell activated carbon sized to 180 to 355 μm was used.
(Thermo-adhesive resin)
A polyester resin having a melting point of 120 ° C. divided to 50 to 300 μm was used.
(Production method)
Melamine phosphate 9g / m2, zinc pyrithione 0.2g / m2 and thiabendazole 0.3g / m2 were mixed with ester binder 3g / m2 in water system, and this was dip-dipped into a thermal bond nonwoven fabric for adhesion processing. Was dried for 10 minutes to produce a thermal bond processed nonwoven fabric A having a basis weight of 53 g / m 2. “G / m 2” indicates the mass per unit area that finally adheres to the nonwoven fabric.
Next, after the mixed granular material mixed and stirred so that the deodorizing agent is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2 is sprayed on the thermal bond processed nonwoven fabric A, the thermal adhesive resin in a drying oven at 150 ° C. Then, a breathable non-woven fabric was laminated thereon and pressed to prepare a filter medium A for air filter.
The bending resistance of the air filter medium A was 650 mg.

[Example 2]
Only the thermal bond nonwoven fabric was produced with the following composition, and the filter medium B for air filters was produced with the composition and method similar to Example 1 other than that.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 45g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 80: 20
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ Composition of core part of heat-sealing fiber: Polyester Melting point of sheath part of heat-sealing fiber: 180 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
-Composition of non-heat-bonding fiber: Polyester-Fineness of non-heat-bonding fiber: 2.2 dtex
The bending resistance of the filter medium B for air filter was 640 mg.

[Example 3]
Only the thermal bond nonwoven fabric was produced with the following composition, and the filter medium C for air filters was produced with the composition and method similar to Example 1 other than that.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 55g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 40: 60
-Fineness of heat-sealing fiber: 2.2 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ The composition of the core portion of the heat-sealing fiber: polyester. The melting point of the sheath portion of the heat-sealing fiber: 150 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
-Composition of non-heat-bonding fiber: Polyester-Fineness of non-heat-bonding fiber: 4.4 dtex
The bending resistance of the filter medium C for air filter was 480 mg.

[Example 4]
A thermal bond nonwoven fabric and a flame retardant were prepared with the following composition, and the air filter medium D was prepared with the same composition and method as in Example 1 except that.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 35g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 80: 20
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
-Composition of the core part of the heat-sealing fiber: Polyester- Melting point of the sheath part of the heat-sealing fiber: 200 ° C
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
-Composition of non-heat-bonding fiber: Polyester-Fineness of non-heat-bonding fiber: 2.2 dtex
(Flame retardants)
A phosphate ester compound having a water solubility of 0.45% was used.
(Production method)
6 g / m2 of phosphate ester, 0.2 g / m2 of zinc pyrithione and 0.3 g / m2 of thiabendazole were mixed in an aqueous system with 3 g / m2 of ester binder, and this was dip-dipped in a thermal bond nonwoven fabric to perform adhesion processing. Was dried for 10 minutes to produce a thermal bond processed nonwoven fabric D having a basis weight of 45 g / m 2.
Next, after the mixed granular material mixed and stirred so that the deodorizing agent is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2 is sprayed on the thermal bond processed nonwoven fabric A, the thermal adhesive resin in a drying oven at 150 ° C. Was melted, and a breathable nonwoven fabric was stacked and pressed to produce a filter medium A for air filter.
The bending resistance of the filter medium D for air filter was 580 mg.

[Example 5]
A thermal bond nonwoven fabric, an antifungal agent, and a thermal adhesive resin were prepared by the following composition and method, and a filter medium E for air filter was prepared by the same composition and method as in Example 1 except that.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 25g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 100: 0
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ Composition of core part of heat-sealing fiber: Polyester Melting point of sheath part of heat-sealing fiber: 180 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
(Anti-mold agent)
Carbendazim with a water solubility of 0.08% was used.
(Thermo-adhesive resin)
A polyester resin having a melting point of 120 ° C. divided into 50 to 300 μm and a polyethylene resin having a melting point of 105 ° C. divided into 150 to 500 μm were mixed and used at a mass ratio of 1: 1.
(Production method)
Melamine phosphate 9 g / m2, zinc pyrithione 0.2 g / m2 and carbendazim 0.3 g / m2 were mixed with ester binder 2 g / m2 in water, and this was dip-dipped into a thermal bond nonwoven fabric to perform adhesion processing. Drying was performed at a temperature of 10 ° C. for 10 minutes to prepare a thermal bond processed nonwoven fabric E having a basis weight of 38 g / m 2.
Next, after mixing the mixed granular material that has been mixed and stirred so that the deodorizer is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2, the thermal bonded resin nonwoven fabric E is dispersed, and then the thermal adhesive resin is heated in a drying oven at 150 ° C. Was melted, and a breathable nonwoven fabric was stacked and pressed to produce a filter medium E for air filter.
The bending resistance of the filter medium E for air filter was 680 mg.

[Example 6]
A thermal bond nonwoven fabric was prepared with the following composition, and no antibacterial agent was added. Other than that, the filter medium E for air filters was produced by the same composition and method as Example 1.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 40g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 100: 0
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ Composition of core part of heat-sealing fiber: Polyester Melting point of sheath part of heat-sealing fiber: 180 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
(Production method)
Melamine phosphate 9g / m2 and thiabendazole 0.3g / m2 are mixed with ester binder 3g / m2 in water system, and this is dip-immersed in a thermal bond nonwoven fabric, followed by adhesion processing, and dried at 160 ° C for 10 minutes. A 52 g / m 2 thermal bond processed nonwoven fabric F was produced.
Next, after spraying the mixed granular material mixed and stirred so that the deodorizer is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2 on the thermal bond processed nonwoven fabric F, the thermal adhesive resin in a drying oven at 150 ° C. Was melted, and a breathable non-woven fabric was superimposed and pressed to produce a filter medium F for air filter.
The bending resistance of the air filter medium F was 680 mg.

[Example 7]
The thermal bond nonwoven fabric and the resin binder were produced with the following composition, and the filter medium G for air filters was produced by the same composition and method as Example 1 other than that.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 45g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 60: 40
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ Composition of core part of heat-sealing fiber: Polyester Melting point of sheath part of heat-sealing fiber: 180 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
-Composition of non-heat-bonding fiber: Polyester-Fineness of non-heat-bonding fiber: 2.2 dtex
(Resin binder)
An acrylic binder was used as the resin binder.
(Production method)
Melamine phosphate 14g / m2, zinc pyrithione 0.2g / m2, and thiabendazole 0.3g / m2 were mixed with acrylic binder 5g / m2 in water system, and this was dip-dipped into a thermal bond nonwoven fabric for adhesion processing. And dried for 10 minutes to produce a thermal bond processed nonwoven fabric G having a basis weight of 65 g / m 2.
Next, after the mixed granular material mixed and stirred so that the deodorizer is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2 is sprayed on the thermal bond processed nonwoven fabric G, the thermal adhesive resin is heated in a drying oven at 150 ° C. Was melted, and a breathable non-woven fabric was laminated and pressed to produce a filter medium G for air filter.
The bending resistance of the air filter medium G was 650 mg.

[Example 8]
The thermal bond nonwoven fabric was produced with the following composition, and the filter medium H for air filters was produced with the composition and method similar to Example 1 other than that.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 85g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 60: 40
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ Composition of core part of heat-sealing fiber: Polyester Melting point of sheath part of heat-sealing fiber: 180 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
-Composition of non-heat-bonding fiber: Polyester-Fineness of non-heat-bonding fiber: 2.2 dtex
(Production method)
Melamine phosphate 13 g / m2, zinc pyrithione 0.2 g / m2, and thiabendazole 0.3 g / m2 were mixed with an ester binder 5 g / m2 in an aqueous system. Was dried for 10 minutes to produce a thermal bond processed nonwoven fabric H having a basis weight of 104 g / m 2.
Next, after the mixed granular material mixed and stirred so that the deodorizer is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2 is sprayed on the thermal bond processed nonwoven fabric H, the thermal adhesive resin in a drying oven at 150 ° C. Was melted, and a breathable nonwoven fabric was superposed and pressed to produce a filter medium H for air filter.
The bending resistance of the air filter medium H was 820 mg.

[Comparative Example 1]
The thermal bond nonwoven fabric was produced with the following composition, and the filter medium I for air filters was produced with the composition and method similar to Example 1 other than that.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 40g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 20: 80
-Fineness of heat-sealing fiber: 2.2 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ The composition of the core portion of the heat-sealing fiber: polyester. The melting point of the sheath portion of the heat-sealing fiber: 150 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
-Composition of non-heat-bonding fiber: Polyester-Fineness of non-heat-bonding fiber: 4.4 dtex
(Production method)
Melamine phosphate 9g / m2, zinc pyrithione 0.2g / m2 and thiabendazole 0.3g / m2 were mixed with ester binder 3g / m2 in water system, and this was dip-dipped into a thermal bond nonwoven fabric for adhesion processing. And dried for 10 minutes to produce a thermal bond processed nonwoven fabric I having a basis weight of 53 g / m 2.
Next, after the mixed granular material mixed and stirred so that the deodorizing agent is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2 is sprayed on the thermal bond processed nonwoven fabric I, the thermal adhesive resin in a drying oven at 150 ° C. Was melted, and a breathable nonwoven fabric was laminated and pressed to produce a filter medium I for air filter.
The bending resistance of the air filter medium I was 240 mg.

[Comparative Example 2]
A thermal bond nonwoven fabric was prepared with the following composition, and no resin binder was used. Other than that, the filter medium J for air filters was produced by the same composition and method as Example 1.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 45g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 80: 20
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ The composition of the core portion of the heat-sealing fiber: polyester. The melting point of the sheath portion of the heat-sealing fiber: 150 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
-Composition of non-heat-bonding fiber: Polyester-Fineness of non-heat-bonding fiber: 2.2 dtex
(Production method)
Melamine phosphate 9g / m2, zinc pyrithione 0.2g / m2 and thiabendazole 0.3g / m2 were mixed in water system, and this was dip dipped into a thermal bond nonwoven fabric to perform adhesion processing and dried at 180 ° C for 10 minutes, A thermal bond processed nonwoven fabric J having a basis weight of 55 g / m 2 was produced.
Next, after spraying the mixed granular material mixed and stirred so that the deodorizing agent is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2 on the thermal bond processed non-woven fabric J, the thermal adhesive resin in a drying oven at 150 ° C. Was melted, and a breathable nonwoven fabric was superposed and pressed to produce a filter medium J for air filter.
The bending resistance of the air filter medium J was 540 mg.
[Comparative Example 3]
A thermal bond nonwoven fabric was prepared with the following composition, and ammonium polyphosphate was used as a flame retardant. Other than that, the filter medium K for air filters was produced by the same composition and method as Example 1.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 50g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 80: 20
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ The composition of the core portion of the heat-sealing fiber: polyester. The melting point of the sheath portion of the heat-sealing fiber: 150 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
-Composition of non-heat-bonding fiber: Polyester-Fineness of non-heat-bonding fiber: 2.2 dtex
(Flame retardants)
Ammonium polyphosphate having a water solubility in water of 36.8% was used.
(Production method)
Ammonium polyphosphate 9 g / m 2, zinc pyrithione 0.2 g / m 2 and thiabendazole 0.3 g / m 2 were mixed with an ester binder 3 g / m 2 in an aqueous system, and this was dip-dipped into a thermal bond nonwoven fabric to carry out adhesion processing. And dried for 10 minutes to produce a thermal bond processed nonwoven fabric K having a basis weight of 63 g / m 2.
Next, after the mixed granular material mixed and stirred so that the deodorizer is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2 is sprayed on the thermal bond processed nonwoven fabric K, the thermal adhesive resin is heated in a drying oven at 150 ° C. Was melted, and a breathable nonwoven fabric was laminated and pressed to produce a filter medium K for air filter.
The bending resistance of the filter medium K for air filter was 560 mg.

[Comparative Example 4]
A thermal bond nonwoven fabric was prepared with the following composition, and catechin was used as an antibacterial agent. Other than that, the filter medium L for air filters was produced by the same composition and method as Example 1.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 50g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 80: 20
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ Composition of core part of heat-sealing fiber: Polyester Melting point of sheath part of heat-sealing fiber: 180 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid modified polyester-Mass ratio of core part and sheath part: 60:40
-Composition of non-heat-bonding fiber: Polyester-Fineness of non-heat-bonding fiber: 2.2 dtex
(Antimicrobial agent)
Catechin (polyphenone 70s (manufactured by Mitsui Norin)) having a solubility in water of 35.0% was used.
(Production method)
Melamine phosphate 9g / m2 and catechin 1.5g / m2 are mixed with ester binder 3g / m2 in water system, and this is dip-immersed in a thermal bond nonwoven fabric and attached, dried at 160 ° C for 10 minutes, A 64 g / m 2 thermal bond processed nonwoven fabric L was produced.
Next, after the mixed granular material mixed and stirred so that the deodorizer is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2 is sprayed on the thermal bond processed nonwoven fabric L, the thermal adhesive resin in a drying oven at 150 ° C. The air-permeable filter material L was produced by fusing the gas, laminating a breathable nonwoven fabric, and performing pressing.
The bending resistance of the air filter medium L was 560 mg.
[Comparative Example 5]
The thermal bond nonwoven fabric was produced with the following compositions, and the resin binder amount was changed. Other than that, the filter medium M for air filters was produced by the same composition and method as Example 1.
(Thermal bond nonwoven fabric)
The thermal bond nonwoven fabric of the following prescription was used.
・ Weight: 45g / m2
・ Heat-bonding fiber: Non-heat-bonding fiber = 70: 30
-Fineness of heat-bonded fiber: 4.4 dtex
-Melting point of the core of the heat-sealing fiber: 260 ° C
・ Composition of core part of heat-sealing fiber: Polyester Melting point of sheath part of heat-sealing fiber: 180 ° C.
-Composition of sheath part of heat-sealing fiber: isophthalic acid-modified polyester-Mass ratio of core part and sheath part: 60:40
-Composition of non-heat-bonding fiber: Polyester-Fineness of non-heat-bonding fiber: 2.2 dtex
(Production method)
Melamine phosphate 6 g / m2, zinc pyrithione 0.2 g / m2 and thiabendazole 0.3 g / m2 were mixed with acrylic binder 8 g / m2 in water system, and this was dip-dipped into a thermal bond nonwoven fabric for adhesion processing. Was dried for 10 minutes to produce a thermal bond processed nonwoven fabric M having a basis weight of 45 g / m 2.
Next, after the mixed granular material mixed and stirred so that the deodorizer is 80 g / m 2 and the thermal adhesive resin is 35 g / m 2 is sprayed on the thermal bond processed nonwoven fabric M, the thermal adhesive resin in a drying oven at 150 ° C. The air-permeable filter medium M was produced by melting the material, superposing the breathable nonwoven fabric, and performing pressing.
The bending resistance of the air filter medium M was 460 mg.

  As can be seen from the table, the air filter medium within the scope of the present invention is an air filter medium that is used under conditions where water is loaded as expected in a cabin filter. In addition, it can exhibit flame retardancy and deodorization performance, and has high rigidity and high water permeability, so that filter deformation can be suppressed.

  In Examples 1 to 4, after fixing a water-insoluble flame retardant, antibacterial agent, and fungicide to the thermal bond nonwoven fabric with a small amount of binder, heat is applied to melt the sheath component of the heat-bonded fiber in the thermal bond nonwoven fabric. As a result, various functional chemicals can be firmly fixed, and high flame retardancy, antibacterial properties and antifungal properties are exhibited before and after being exposed to water. Furthermore, the antiviral property can be expressed because the functional agent is not coated and is attached to the fiber.

  In Example 6, it was confirmed that both antibacterial performance and fungicidal performance could be achieved with only thiabendazole, and within the scope of the present invention, antibacterial performance, fungicidal performance, and flame retardancy performance before and after water exposure It was confirmed that the standard was achieved.

  In Example 7, an acrylic binder was used as the binder. Since the acrylic binder is flammable, a large amount of flame retardant is added.

  In Example 8, the basis weight of the thermal bond nonwoven fabric was 85 g / m2. Since the amount of fiber is large, a large amount of flame retardant is added.

  In Comparative Example 1, the ratio of the heat-sealing fiber to the non-heat-sealing fiber is 20:80, and the ratio of the heat-sealing fiber is extremely low, so that various functional agents cannot be firmly fixed to the fiber surface. Has reduced antibacterial and antifungal performance. In addition, it was confirmed that the deodorizing performance was lowered by the eluted functional agent blocking the pores of the deodorizing agent.

  In Comparative Example 2, since no binder is used, various functional agents are not easily fixed to the surface of the thermal bond nonwoven fabric, and the anti-mold performance is low even before being exposed to water. Furthermore, it was confirmed that both the flame retardant performance and the antibacterial performance were degraded after being exposed to water.

  In Comparative Example 3, since water-soluble ammonium polyphosphate was used as the flame retardant, the flame retardant eluted during exposure to water and entered into the pores of the deodorant. A decline in performance was also confirmed.

  In Comparative Example 4, water-soluble tea catechin was used as the antibacterial agent, but it was eluted at the time of exposure to water, and a decrease in antibacterial performance was confirmed. Moreover, since the tea catechin has no antifungal performance, it was confirmed that the antifungal performance is extremely low.

  In Comparative Example 5, since the amount of the resin binder was large, a large amount of the functional particles were covered with the resin binder, and the antibacterial performance was not sufficiently developed. Moreover, it was confirmed that the flame retardance was not sufficient because the amount of the resin binder was large.

  The filter material for an air filter according to the present invention is an air filter for purifying air in a vehicle interior of an automobile, a railway vehicle, etc., an air cleaner used in a healthy house, a pet-compatible apartment, an elderly entrance facility, a hospital, an office, etc. It is preferably used as an air filter medium such as a machine filter, an air conditioner filter, an OA equipment intake / exhaust filter, a building air conditioner filter, and an industrial clean room filter.

Claims (11)

A filter medium for an air filter in which a deodorizer is supported between a thermal bond nonwoven fabric and a breathable nonwoven fabric via a thermal adhesive resin, wherein the thermal bond nonwoven fabric masses the heat-bonded fiber and the non-heat-bonded fiber. A water-insoluble flame retardant and a water-insoluble antibacterial and / or antifungal agent are supported on the thermal bond nonwoven fabric via a resin binder, in a ratio of 40:60 to 100: 0. The air filter medium is characterized in that the amount of the resin binder attached is 3% by mass to 15% by mass with respect to the thermal bond nonwoven fabric. The air filter medium according to claim 1, wherein the resin binder is a polyester binder. The air filter medium according to any one of claims 1 to 2, wherein the water-insoluble flame retardant is melamine polyphosphate. The air filter medium according to any one of claims 1 to 3, wherein the water-insoluble antibacterial and antifungal agent is selected from a benzimidazole compound and zinc pyrithione. The air according to any one of claims 1 to 4, wherein the heat-bonding fiber of the thermal bond nonwoven fabric has a core-sheath structure, and the melting point of the sheath part is 140 ° C to 200 ° C. Filter media for filters. The filter medium for an air filter according to claim 1, basis weight of the thermal bond nonwoven fabric is characterized in that it is a 15 to 60 g / m ^2. The air filter medium according to any one of claims 1 to 6, wherein the thermal adhesive resin is selected from at least a polyester resin or a polyethylene resin. The air-permeable filter medium according to any one of claims 1 to 7, wherein the breathable nonwoven fabric is a thermal bond nonwoven fabric or a spunbond nonwoven fabric made of polyester fibers. An air filter comprising the air filter medium according to claim 1. After fixing a water-insoluble flame retardant and / or a water-insoluble antibacterial and antifungal agent to the thermal bond nonwoven fabric by heat treatment through a resin binder, deodorization is performed between the thermal bond nonwoven fabric and the breathable nonwoven fabric. The method for producing an air filter medium according to any one of claims 1 to 8, wherein the agent and the thermoadhesive resin are dispersed and integrated by thermocompression bonding. After fixing a water-insoluble flame retardant and one or both of a water-insoluble antibacterial agent and fungicide through a resin binder between the breathable nonwoven fabric by heat treatment, between the thermal bond nonwoven fabric and the breathable nonwoven fabric. The method for producing an air filter medium according to any one of claims 1 to 8, wherein the deodorizer and the thermal adhesive resin are dispersed and integrated by thermocompression bonding.