JP2005152432A - Deodorizing filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that air-permeable resistance is increased by a binder for fixing a deodorant held between two non-woven fabrics in a conventional deodorizing filter. <P>SOLUTION: In the deodorizing filter using a deodorizing sheet resulting from laminating in the order and thermocompression bonding a first gas-permeable non-woven fabric material composed of a thermoplastic resin, a porous adsorbent including smell component adsorption and a second gas-permeable non-woven fabric material composed of a thermoplastic resin, apparent thickness of at least one gas-permeable non-woven fabric material before thermocompression bonding is settled within the range of 0.5 to 0.3 mm, so that the apparent thickness is reduced by 10 to 90% by thermocompression bonding. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a deodorizing filter suitable for removing a wide variety of odors in homes, office spaces, and living spaces such as automobile interiors.

  There is known a deodorizing filter obtained by pleating a deodorizing sheet in which activated carbon is sandwiched between a nonwoven fabric and a binder together with a binder.

  In this conventional deodorizing filter, since a binder is used, there exists a problem that ventilation resistance becomes high.

  Further, if the binder is not used, the ventilation resistance is lowered, but the activated carbon cannot be held and fixed, so that it is not established as a deodorizing filter.

  Japanese Patent Application Laid-Open No. 2002-291860 discloses a method in which a thermoplastic base material and an adsorbent are sandwiched between two air-permeable base materials and integrated by a fusion action of the thermoplastic base material.

  However, in this case, since the conventional binder is merely replaced with a thermoplastic base material, the decrease in the airflow resistance is small, and if a material with a high opening ratio is used to reduce the airflow resistance, the adsorbent is held and fixed. Becomes difficult.

Japanese Patent Application Laid-Open No. 2003-293253 discloses a method of incorporating particles into the nonwoven fabric by thermal shrinkage of the nonwoven fabric. However, when the particles are filled into the nonwoven fabric, the particles fall off or the outermost particles after pressing. Since it is easy to spill out, it is safer to avoid installation in a device with wind flow such as an air-conditioning filter from the viewpoint of user safety.
JP 2002-291860 A JP 2003-293253 A

  The problems to be solved are that in conventional deodorizing filters, the airflow resistance is increased by the binder that fixes the deodorant sandwiched between the two nonwoven fabrics, and the deodorant particles are retained by the thermal shrinkage of the nonwoven fabric. Attempting to do so may cause the deodorant particles to scatter. In general, deodorization performance decreases when the ventilation resistance is lowered. The present invention improves the deodorization performance while lowering the ventilation resistance.

  In the present invention, a first breathable nonwoven fabric substrate made of a thermoplastic resin, a porous adsorbent having odor component adsorptivity, and a second breathable nonwoven fabric substrate made of a thermoplastic resin are laminated in this order. A deodorizing filter using a deodorizing sheet thermocompression bonded together, and the apparent thickness of the at least one breathable nonwoven fabric substrate before thermocompression bonding is within a range of 0.5 to 3.0 mm by thermocompression bonding. Is reduced by 10 to 90%.

  In the present invention, since the binder spreads by performing thermocompression bonding while compressing the breathable nonwoven fabric substrate so that the apparent thickness is reduced, the amount of the binder to be used can be reduced. Thereby, since the surface of the porous adsorbent is not easily blocked by the binder, the airflow resistance is reduced and the odor component adsorption ability is improved. Therefore, the deodorizing performance is improved and the manufacturing cost is reduced. It should be noted that if the apparent thickness of the breathable nonwoven fabric substrate is small, it is difficult to compress, and if the apparent thickness is large, the tensile strength is reduced and manufacturing becomes difficult. It is within the range of 5 to 3.0 mm.

  Also, if the porous fabric adsorbent has a small basis weight and the porous adsorbent may spill out, the apparent thickness of one breathable nonwoven fabric base should be within the above range, and the other breathable nonwoven fabric It is preferable to make the apparent thickness of the substrate smaller than that to prevent the porous adsorbent from scattering.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The deodorizing filter of this embodiment includes a first breathable nonwoven fabric substrate made of a thermoplastic resin, a porous adsorbent having odor component adsorptivity, and a second breathable nonwoven fabric substrate made of a thermoplastic resin. A deodorizing sheet formed by laminating in this order and thermocompression bonding is used.

  And in order to ensure the effective area as a filter, this deodorizing sheet is pleated and made into the deodorizing filter.

  The first and second breathable nonwoven fabric base materials are selected from one or more materials according to breathability, strength, and workability from thermoplastic resins such as polypropylene, polyester, polyethylene, polystyrene, and polyamide resins. It is possible to use a mixed mixture.

  When polypropylene or polyester is used, the melting point is relatively low (about 100 to 150 ° C.) and the thermocompression bonding time is short, so the productivity is good and the thermal energy of the production equipment is reduced. Production costs can be reduced.

  In addition, when a non-woven fabric having polyester as a core and covered with polypropylene is used, desired strength can be ensured and polypropylene can be thermocompression bonded at a low temperature, which is advantageous in terms of productivity and cost. It is.

The basis weight of the nonwoven fabric is in the range of 25 to 70 g / m ² . When it is less than 25 g / m ² , the porous adsorbent falls off, and when it is greater than 70 g / m ² , the ventilation resistance increases, and when used in a filter for an air conditioner or an air purifier, This is because there is a risk of putting an excessive burden on the fans.

  Also, the apparent thickness of the nonwoven fabric is difficult to compress if it is small, and if it is large, the tensile strength becomes small and it becomes difficult to produce a deodorizing sheet, so the apparent thickness before thermocompression is 0.5 to 3.0 mm. And within a range of 10 to 90% by thermocompression bonding.

  Here, the apparent thickness is a thickness in a state where the nonwoven fabric is not crushed. That is, if the thickness is less than 0.3 mm, the change in thickness is small even when measured with calipers or the like, but in the present invention, a soft nonwoven fabric with a thickness of 0.5 mm or more is used. Therefore, when calipers are used, the thickness changes greatly.

  The porous adsorbent is preferably composed of an adsorbent containing at least one adsorbent selected from activated carbon, zeolite, silica gel, alumina and the like. In particular, activated carbon is preferable because it is low in cost and excellent in odor component adsorption.

As the activated carbon, those made of various raw materials can be suitably used. Among them, coconut shell activated carbon having a large specific surface area of about 800 to 1500 m ² / g is particularly preferable because of its excellent odor adsorption performance. Moreover, the mesh (particle size) of activated carbon can be used conveniently within the range of about 4 to 100 mesh.

  In addition, by combining several kinds of adsorbents, it becomes possible to adsorb various odor components with a single deodorizing sheet, so that deodorization can be performed efficiently and effectively.

  Further, depending on the use and place of use of the deodorizing filter, chemical adhering treatment may be performed so as to selectively adsorb a specific odor component to the porous adsorbent. For example, when deodorizing an aldehyde, an amino group-containing organic compound may be added. Examples of amino group-containing organic compounds include amino group-containing organic silicon compounds such as γ-glycidoxylpropyltriethoxysilane and γ-aminopropyltriexylsilane, and aromatic amines such as aniline and dimethyltrimethyl-silylamine. Can be used.

  In addition, the aniline attachment treatment may be performed by preparing an attachment solution containing aniline, and immersing the activated carbon in the attachment solution for a predetermined time and stirring it so as to be supported in the pores of the activated carbon at a predetermined weight percentage.

  In this case, the supported amount is 0.5 to 10% by weight, preferably 2 to 6% by weight. This is because if the loading amount is less than 0.5% by weight, the desired loading effect may not be obtained, and if it is more than 10% by weight, the original adsorption ability of activated carbon may be hindered.

  Moreover, if the activated carbon carries a catalyst for decomposing odor components, the life of the deodorizing filter can be extended. Examples of such a catalyst include noble metal catalysts such as ruthenium and platinum, photocatalysts such as titanium oxide, and catalyst-reactive ones such as artificial enzymes.

  If ruthenium tetroxide is present in the ruthenium catalyst, ruthenium tetroxide, which has strong oxidizing power, undergoes an oxidation-reduction reaction with some of the adjunct components and is reduced to ruthenium dioxide. It becomes difficult to obtain the amount and the effect of adhesion. Therefore, when a ruthenium catalyst and an adjunct component are used in combination, it is preferable to use a ruthenium catalyst that does not contain ruthenium tetroxide.

  A ruthenium catalyst not containing ruthenium tetroxide is prepared by preparing a solution containing a chloride containing Ru element (ruthenium chloride, ruthenium chloride hydrate, etc.), dipping the activated carbon in the solution for a predetermined time, and reducing and drying. Thus, it may be supported at a predetermined weight percent in the pores of the activated carbon.

  In this case, the loading is preferably 0.1 to 10% by weight, preferably 1 to 5% by weight. When the amount is less than 0.1% by weight, the desired odor component decomposition activity may not be obtained. When the amount is more than 10% by weight, the activity decreases due to secondary aggregation of the ruthenium catalyst. This is because the decomposition effect corresponding to the high cost cannot be expected.

  The combination of the first porous adsorbent carrying an additive such as an amino group-containing organic compound and the second porous adsorbent carrying an odor decomposable catalyst such as ruthenium catalyst is the first porous adsorption. The second porous adsorbent may be mixed in an amount of 5 to 50% by weight, preferably 7 to 25% by weight, based on the agent. When the second porous adsorbent is less than 5% by weight, the desired odor component decomposition performance may not be obtained. When the second porous adsorbent is more than 50% by weight, the cost immediately increases and is generally used later. This is because when used in a filter for an air conditioner or an air purifier, the price may not be easily purchased by the user.

When the porous adsorbent of this embodiment is processed into a sheet shape, the deodorizer is supported at 100 to 400 g / m ² , preferably 150 to 300 g / m ² . When the loading amount is less than 100 g / m ² , the desired deodorizing performance may not be obtained. When the loading amount is more than 400 g / m ² , the air permeability is low, and when used as a filter for an air conditioner or an air purifier. This is because an excessive burden may be placed on the fan for blowing air.

  When sandwiching the porous adsorbent between the nonwoven fabrics, a binder made of hot melt or the like can be used. In this case, in order to achieve both low ventilation resistance and high deodorization performance, the binder is preferably 40% by weight or less with respect to the porous adsorbent.

  The pleating process can be performed within a folding width of 10 to 50 mm, preferably 15 to 35 mm. When the folding width is smaller than 10 mm, the contact efficiency of the odor component to the porous adsorbent is low, and the desired one-pass deodorizing performance may not be obtained. When the folding width is larger than 50 mm, the air conditioner or the air cleaner This is because it takes up too much space as a filter for use, and there is a risk of securing a flow path and excessively restricting other parts.

  The pitch of the pleats can be processed within a range of 3 to 15 mm, preferably 4 to 10 mm. When the pitch is smaller than 3 mm, the ventilation resistance is increased, and when used for a filter for an air conditioner or an air purifier, an excessive load is imposed on the fan for blowing air. This is because the one-pass deodorizing performance may not be obtained.

  The method of fixing the pleated sheet-like deodorizing filter to the frame can be fixed to a plate-like frame made of resin or cardboard at a predetermined pleat pitch using an adhesive such as a binder or hot melt.

  The following examples illustrate the present invention more specifically. In addition, this Example is an example of the structure of this invention, and this invention is not limited to this.

(Example 1)
A first activated carbon in which aniline is supported at a rate of 4% by weight on the activated carbon, and a second activated carbon in which a ruthenium catalyst not containing ruthenium tetroxide is supported at a rate of 5% by weight on the activated carbon, Is a first breathable nonwoven fabric base material made of polypropylene (apparent thickness of about 1.0 to 1.2 mm, basis weight of 30 g). / M ² ) and a second breathable nonwoven fabric substrate made of polyester (apparent thickness 0.5 mm or less, basis weight 34 g / m ² ) so that the carrying amount is 200 g / m ^2. Then, thermocompression bonding was performed using a polyolefin-based binder (15% by weight with respect to the deodorizing agent) mixed in advance to prepare a deodorizing sheet. In addition, the thickness of the 1st air permeable nonwoven fabric base material after thermocompression bonding is about 0.2 mm. Then, the deodorizing sheet was pleated to obtain a deodorizing filter.

(Comparative Example 1)
A deodorizing agent having the same composition as that of Example 1 was loaded between a first and second breathable nonwoven fabric substrates made of polyester (apparent thickness of 0.5 mm or less, basis weight 34 g / m ² ) at a load of 200 g / m. ^A deodorizing sheet was prepared by performing thermocompression bonding using a polyolefin binder (30% by weight with respect to the deodorizing agent) that was laminated so as to be ² and mixed in advance. Then, the deodorizing sheet was pleated to obtain a deodorizing filter.

(Performance evaluation)
FIG. 1 shows the results of a DIN test (pseudo exhaust gas deodorization test) using the deodorization filters of Example 1 and Comparative Example 1 described above. As shown in the figure, it can be seen that the deodorization filter of Example 1 has higher deodorization efficiency than the deodorization filter of Comparative Example 1. That is, since the deodorizing filter of Example 1 has a smaller amount of binder than that of Comparative Example 1, it can effectively utilize the odor component adsorption ability of the deodorizing agent.

  Furthermore, the thing of Example 1 has the advantage that a deodorizing agent is hard to fly compared with what hold | maintains a deodorizing agent by the thermal contraction of a nonwoven fabric.

  In addition, the deodorizing filter by this invention is suitable for the air conditioner and air cleaner for general use or vehicle interior.

It is a graph which shows the performance evaluation test result of the deodorizing filter of this invention, and the conventional deodorizing filter.

Claims (11)

  A first breathable nonwoven fabric substrate made of a thermoplastic resin, a porous adsorbent having odor component adsorptivity, and a second breathable nonwoven fabric substrate made of a thermoplastic resin were laminated in this order and thermocompression bonded. A deodorizing filter using a deodorizing sheet, wherein the apparent thickness before thermocompression bonding of at least one of the breathable nonwoven fabric substrates is within a range of 0.5 to 3.0 mm, and the apparent thickness is 10 to 10 by thermocompression bonding. A deodorizing filter characterized by being reduced by 90%.   2. The deodorizing filter according to claim 1, wherein the first and second breathable nonwoven fabric substrates include at least one thermoplastic resin selected from polypropylene, polyester, polyethylene, polystyrene, and polyamide resin. .   3. The deodorizing filter according to claim 2, wherein the first and second breathable nonwoven fabric substrates are nonwoven fabric substrates having polyester as a core material and covered with polypropylene. It said first and second breathable nonwoven substrate, deodorizing filter according to claim 1 any one of claims 3 to its basis weight is equal to or is in the range of 25~70g / m ² .   The deodorizing filter according to claim 1, wherein the porous adsorbent contains at least one adsorbent selected from activated carbon, zeolite, silica gel, alumina and the like.   6. The deodorizing filter according to claim 1 or 5, wherein the porous adsorbent is subjected to a chemical attachment treatment that selectively adsorbs a specific odor component.   The deodorizing filter according to claim 1, wherein the porous adsorbent carries an odor component decomposable catalyst.   The deodorizing filter according to any one of claims 1, 5, 6, and 7, wherein the porous adsorbent is a mixture of at least two adsorbents. The deodorizing sheet, deodorizing filter of any one of claims 1,5,6,7,8, characterized in that carrying the porous adsorbent within the 100 to 400 g / ^{m 2} .   The deodorizing filter according to any one of claims 1 to 9, wherein a binder made of hot melt or the like is contained at a ratio of 40% by weight or less with respect to the porous adsorbent.   The deodorizing filter according to any one of claims 1 to 10, wherein the deodorizing sheet is pleated.

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