JP2002113075A - Regenerative nitrogen oxide deodorizing filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long-life regenerative nitrogen oxide deodorizing filter comprising two base sheets with a deodorant and a regenerating agent enclosed in-between, which is plural times regenerated by a simple regeneration method. SOLUTION: The regenerative nitrogen oxide deodorizing filter has a flat enclosing deodorizing filter comprising the base material sheet A, the base material sheet B, and a deodorant layer enclosed between them, and a nitrogen oxide deodorant and a regenerating agent for the nitrogen oxide deodorant are enclosed in the deodorant layer. In addition, the regenerative nitrogen oxide deodorizing filter with the pleated filter and a method of regenerating the filters are also provided here.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing indoors,
Nitrogen oxides contained in outside air taken into the room when you are young
The present invention relates to a nitrogen oxide deodorizing filter configuration for effectively deodorizing (hereinafter referred to as NOx) and a method for regenerating the nitrogen oxide deodorizing filter.

[0002]

2. Description of the Related Art From the viewpoint of energy saving, recent living spaces are becoming highly airtight and highly insulated, and higher air conditioning is required. The main elements related to such air conditioning are:
Examples include temperature control, humidity control, and harmful air component control. Among these, various types of heating systems, cooling systems, or humidification systems have been developed for devices that realize temperature control and humidity control, and are generally satisfactory.
However, regarding a device for controlling harmful air components, a harmful air component control technology itself is under development, and a device that can provide sufficient control has not yet been developed.

[0003] As a device for controlling harmful air components, a home air purifier for purifying air by removing indoor odorous gas has been put to practical use, but the outside air introduced into an air conditioning system having a ventilation function has been introduced. No technology for air purification has been established. The main pollutants of the outside air are harmful gases such as nitrogen oxides (NOx) contained in vehicle exhaust gas and unpleasant odorous gases generated from the environment.

[0004] Many chemical species are known as nitrogen oxides, which are pollutants of the atmosphere. However, the only thing that stably exists in the atmosphere is nitric oxide (NO) contained in vehicle exhaust gas, Nitrogen dioxide (NO2) oxidized in the atmosphere. It is well known that nitrogen dioxide is harmful to the human body, and 40 to 60 ppb is specified as an environmental standard concentration that does not adversely affect health. Since there is no data indicating that nitric oxide is harmful, no environmental standard concentration is specified. Therefore, removal of nitrogen oxides targets NO2 harmful to the human body.

Conventionally, many techniques for removing nitrogen monoxide in exhaust gas have been developed as techniques for removing nitrogen oxides. For example, Japanese Patent Application Laid-Open No. 50-104783 discloses a technique for efficiently removing nitrogen monoxide in exhaust gas using a catalyst mainly comprising a cobalt complex.
Japanese Patent Application Laid-Open No. 52-134867 discloses a technique for reducing nitrogen monoxide in exhaust gas using a catalyst mainly composed of metal phthalocyanine and metal porphyrin to render the catalyst harmless. However, such a technique for removing nitrogen oxides in exhaust gas cannot be used as it is for removing nitrogen oxides for air conditioning. That is, the former and the latter have different target nitrogen oxides, and the gas concentration to be handled is on the ppm level in the former, whereas the latter is on the ppb level in the latter, and different measures are required.

Under these circumstances, Japanese Patent Application Laid-Open No. 56-133549
And Japanese Patent Application Laid-Open No. 5-220337 disclose a technique for removing nitrogen oxides for air conditioning. The former is a heat exchange type ventilator that treats outside air, incorporating a filter-type air purifier that combines a dry NOx / SOx remover with a composition similar to gypsum and an activated carbon, and the device is a stationary type. It is. In the latter, a heat-exchange rotor is made to rotate coaxially with a NOx removal rotor in which activated carbon fiber made into a sheet is formed into a cylindrical shape, and the apparatus is a rotary type.

When the adsorbent is actually used, it is indispensable from the economical point of view to regenerate the adsorbent having reduced adsorbing power by adsorbing nitrogen oxides so that the adsorbent can be used repeatedly. . In order to regenerate such adsorbents, a regeneration method using overheat treatment is generally known. However, it is necessary to develop a regeneration system that can easily treat end users who handle general household air purifiers. Had been.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have come to invent a regenerative nitrogen oxide deodorizing filter.

(1) In a planar encapsulated deodorizing filter comprising a base material A, a base material B and a deodorant layer enclosed between the substrates, a nitrogen oxide deodorant and a nitrogen oxide deodorant are added to the deodorant layer. A regenerative nitrogen oxide deodorizing filter that contains a regenerating agent.

(2) In the regeneration type nitrogen oxide deodorizing filter of claim 1, the nitrogen oxide regeneration treatment agent is potassium hydroxide, sodium hydroxide, calcium hydroxide, potassium carbonate, sodium carbonate, calcium carbonate, hydrogen carbonate. A regenerative nitrogen oxide deodorizing filter comprising at least one selected from potassium, sodium bicarbonate, and calcium bicarbonate.

(3) A regenerative nitrogen oxide filter unit obtained by processing the regenerative nitrogen oxide deodorizing filter of claims 1 and 2 into a pleated shape.

(4) The nitrogen oxide deodorizing agent having a reduced effect by absorbing the nitrogen oxides by dissolving the encapsulated regenerating agent by washing the regenerative nitrogen oxide deodorizing filters of claims 1 to 3 with water. A deodorant treatment method for regenerating characteristics.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The components relating to the regenerative nitrogen oxide deodorizing filter of the present invention will be described. First, the configuration of the regenerative nitrogen oxide deodorizing filter in the first invention of the present invention will be described in detail in order.

The base material or base material B according to the present invention includes woven fabrics, nonwoven fabrics, nets, sponges, etc., as well as general-purpose thermoplastic films and thin plates such as polyethylene films, polypropylene films, and polyester films. Is mentioned. Of these, a sheet having poor air permeability such as a film or a thin plate may be provided with fine holes to improve the air permeability. Among them, in particular, when a nonwoven fabric or the like is used, relatively uniform air permeability can be ensured, and the encapsulation process is also easy, so that it is advantageously used. The substrate A and the substrate B may be the same or different substrates.

As the base material A or base material B according to the present invention, a material having functions such as antibacterial, antifungal, antiviral, insect repellent, deodorizing, deodorizing, and dust removal may be used as necessary. . Among them, those having antibacterial, antifungal and antiviral functions are preferable, and the substrate A or the substrate B may be an electret or a filter carrying a photocatalyst.

The non-woven fabric is made of polyamide fiber, polyester fiber, polyalkylene paraoxybenzoate fiber, polyurethane fiber, polyvinyl alcohol fiber, polyvinylidene chloride fiber, polyvinyl chloride fiber, polyacrylonitrile fiber, polyolefin fiber. , Synthetic fibers such as phenolic fibers, inorganic fibers such as glass fibers, metal fibers, alumina fibers, activated carbon fibers,
It is produced by various methods using natural fibers such as wood pulp, hemp pulp, and cotton linter pulp, regenerated fibers, or fibers obtained by imparting functions such as hydrophilicity and flame retardancy to these fibers.

The method for producing the nonwoven fabric is not particularly limited, and the web obtained by a dry method, a wet papermaking method, a melt blow method, a spun bond method, etc. may be subjected to a hydroentanglement method, a needle punch method, a stitch according to the purpose and application. Physical method such as bonding method, thermal bonding method such as thermal bonding method,
It can be manufactured by appropriately combining methods of developing strength by an adhesion method using an adhesive such as a resin bond.

An electret filter, a HEPA filter, a filter carrying a fragrance as a substrate according to the present invention, a filter in which an adsorbent or a catalyst is kneaded in a thermoplastic resin and a part thereof is exposed on the surface,
A filter carrying a deodorant such as an enzyme or a filter carrying a deodorant or an antibacterial agent can be used.

The electret filter according to the present invention is a filter that maintains electric polarization semipermanently and applies an electric force to the outside, and traps particles by the electrostatic force. Examples of the charging method include an electro-electret, a heat electret, a radio-electret, a mechano-electret, a photo-electret, a magnet-electret and the like. As a filter material, polypropylene or a propylene-based copolymer is often used.

Since the nonwoven fabric is bulky and has three-dimensional voids, it is difficult to obtain a stable charging effect by charging treatment using corona discharge or the like. However, a film that has been subjected to charging treatment by corona discharge or the like is cut into fibers, and a split fiber electret filter made of non-woven fabric, or a high voltage is applied during melt-blow spinning and melt spinning to charge the fibers as heat electret. The melt blown nonwoven fabric type electret filter and the spunbond nonwoven fabric type electret filter can obtain a stable polarization charge. In addition, since the melt blown nonwoven fabric type electret filter alone has low mechanical strength, it may be used by laminating a dry nonwoven fabric or a spun bond.

The HEPA filter according to the present invention is:
An ultra-high-performance dust collection filter having a dust collection efficiency of 99.97% or more for 0.3 μm particles. Conventionally, HEPA filters have been used for special purposes such as for military use, for radioactive waste, and for clean rooms. However, in recent years, the use of HEPA filters has tended to expand to household use such as home air purifiers.

The nitrogen oxide deodorant according to the present invention is a general term for chemicals used for the purpose of removing nitrogen oxides by adsorption and catalytic action. Specifically, activated carbon, impregnated activated carbon, zeolite, activated alumina, Activated clay, ion-exchange resin, adsorption deodorants such as iron ascorbic acid and iron phthalocyanine derivatives, low-temperature oxidation catalysts such as manganese oxides and perovskite catalysts, photocatalysts such as titanium oxide and zinc oxide, and compounds contained in plant extraction components And deodorants using catechin, tannin, flavonoid and the like. If necessary, a plurality of these deodorants may be used in combination, or a hybrid deodorant obtained by combining these deodorants may be used.

Examples of the nitrogen oxide regeneration treatment agent according to the present invention include water-soluble agents such as potassium hydroxide, potassium carbonate, sodium carbonate, sodium hydrogencarbonate, calcium hydroxide, calcium carbonate, sodium hydroxide, and potassium hydroxide. Alkaline agents are preferred. However, when used as a filter enclosed in a state mixed with an adsorbent, any filter may be used as long as the ability to remove nitrogen oxides can be recovered by performing some kind of regeneration treatment. is not.

The nitrogen oxide regenerating agent does not act when the filter is used, and is used as a treating agent after the nitrogen oxide filter has been used for a long period of time, after the deodorizing performance has been reduced. By immersing the filter in water as a regeneration method, the enclosed water-soluble treatment agent dissolves out,
The deodorant whose deodorization performance has been reduced is subjected to a regeneration treatment. A similar effect can be obtained by preparing a cleaning solution in which similar chemicals are dissolved and performing a regenerating process, but it is not very practical for an actual filter user to perform such a cleaning process. By enclosing the regenerating agent of the present invention in a state mixed with a deodorant, the regenerating process can be performed only by immersing the agent in a certain amount of water.

The binder according to the present invention is a thermoplastic resin, a thermosetting resin, a hot melt, a heat seal, a two-part curable adhesive, a moisture curable adhesive, an ultraviolet ray or an electron beam curable adhesive, and the like. Among them, examples of the thermoplastic resin that is used predominantly include ethylene vinyl acetate copolymers or modified products thereof, ethylene acrylate copolymers, ionomers, polyamides, nylons, polyesters, polyethylenes, polypropylenes, and polyurethane-based resins. it can.

The softening point or melting point of the binder according to the present invention is not particularly limited, and may be appropriately selected in consideration of the post-processing conditions of the filter, the environmental temperature of use, the heat resistance of the substrate or the deodorant, and the like. .

The deodorant according to the present invention may be in the form of a powder,
It is preferably in the form of granules, whiskers, short fibers, or long fibers. The particle size of the deodorant or the thermoplastic adhesive according to the present invention is preferably 10 to 100 mesh. If the particle size is less than 10 mesh, there are problems such as cracking of the activated carbon at the time of pressurization and non-uniform bonding points between the base materials. There is a problem. For the same reason, the shape of the binder according to the present invention is powdery, granular, whisker-like,
Various forms such as a short fiber form and a long fiber form can be adopted, and further, a liquid form, a semi-solid form, a sheet form and the like can be adopted.

Although the amount of the deodorant according to the present invention is not particularly limited, it is preferably 800 g / m ² or less. If the encapsulation amount exceeds 800 g / m ² , the adhesive strength between the substrates becomes low, and when the thickness becomes large and pleating is performed, the processing becomes difficult and the practicability is reduced.

When the deodorant and the thermoplastic adhesive are sprayed on the base material according to the present invention, both may be sprayed individually, but if the deodorizing property is not particularly affected, they are mixed in advance. Is preferably sprayed. As a method of spraying,
Spraying by free fall from the lower part of the hopper, continuous feeding to gravure rolls or other rolls with recesses and feeding onto the substrate, spraying by air blowing in the air, spray coating or die coating with aqueous dispersion And the like.

In the present invention, it is necessary to provide a portion in which the deodorant is arranged at regular intervals and a portion in which the deodorant is not arranged on the inner surface of the planar encapsulated deodorizing sheet, and bond the planar encapsulated deodorizing sheet. To arrange deodorants at regular intervals A method of continuing and suspending the deodorant from the hopper at regular intervals while the base material is running, regularly forming concave parts on rolls with concave parts such as gravure rolls A method of controlling the supply of deodorants by regularly interrupting the ventilation in the method of dispersing in the air, creating a place where no deodorant is regularly supplied to the substrate, Means for mechanically controlling the supply of the deodorant by spray coating or die coating.

In the present invention, it is necessary to supply only the binder to the portion where the deodorant is not disposed on the inner surface of the planar enclosed deodorizing sheet. There are roughly two methods. The first is a method of spraying a binder over the entire surface of the substrate regardless of the presence or absence of a deodorant. The spraying of the binder may be performed before or after spraying the deodorant. The second method is to place the binder only in the area where the deodorant was not placed.This is a method of dropping the binder from the hopper so that the intermittent supply of the deodorant is completely reversed while the substrate is running. Is continued and interrupted, and the binder is regularly (ie, only the portion where the deodorant is not disposed) supplied onto the substrate by another gravure roll having a concave portion only in the non-supply portion of the gravure roll supplied with the deodorant. The method can be used by applying a technique for intermittently supplying a deodorant, such as a method for performing the method. In this case, there is no problem in detecting the presence or absence of the deodorant with a timing mark or the like and determining the timing of binder supply.

In the present invention, the bonding of two substrates can be achieved by heating, pressing, or both. The heating method is not particularly limited, but when the binder is a thermoplastic resin, it is preferable to heat from the side where the binder is sprayed. When heating from the side where the thermoplastic resin is sprayed, since it is difficult to heat by contact heat conduction, it is preferable to use a non-contact heating means such as hot air, among which infrared heaters and gas burner heaters Such a means using radiant heat is particularly preferred.

As the pressurization after the substrates according to the present invention are overlaid, for example, a method of passing between pressurized rolls can be adopted. The degree of pressurization may be appropriately set in consideration of the adhesive strength, the crush of the deodorant, the influence on the air permeability, and the like.

According to the present invention, in the case of a planar encapsulated deodorizing sheet in which a deodorant is sandwiched between two base materials, if the deodorant falls off from the cut surface or is pleated (folded), the inside of the folded portion is formed. In order to solve the problem that the deodorant breaks through the base sheet, etc., it is necessary to provide a deodorant at regular intervals on the inner surface of the planar enclosed deodorant sheet and provide an area where the deodorant is not disposed. Thus, the area where the deodorant is not disposed is cut or formed into a folded portion of the pleat, thereby preventing the deodorant from falling off and breaking the base sheet.

[0035]

EXAMPLES The present invention will be described below with reference to examples, but it should not be construed that the invention is limited thereto without departing from the spirit of the present invention.

Preparation Example 1 Polypropylene fiber (4d, 38mm, 50w%), polyethylene fiber (6d, 51mm, 30w%) and viscose rayon fiber (3d, 51mm, 20w%) were mixed and dried in air by a dry method. To form a web, then
It was impregnated in acrylic latex, which is a thermoplastic binder, and was bonded to fibers to form a nonwoven fabric. Next, this nonwoven fabric is impregnated with a coating solution containing an antibacterial / antifungal agent comprising fine particles of pyridinethiol zinc salt to carry 1 g / m ^{2 of the} pyridinethiol zinc salt.
Was prepared.

Preparation Example 2 Polyester fiber (Tetron, 3d, 38 mm, 50 w
% / 6d, 51 mm, 30 w%) and viscose rayon fiber (3 d, 51 mm, 20 w%), form a web in the air by a dry method, and then form an acrylic latex as a thermoplastic binder A nonwoven fabric was obtained by impregnating the inside and bonding the fibers. Next, the nonwoven fabric was impregnated with a coating solution containing an antibacterial agent in which persimmon catechin was supported on a silica gel carrier to carry an antibacterial agent coating solution at 20 g / m ² ,
A substrate 2 supporting an antimicrobial agent was prepared.

Preparation Example 3 Ultrafine glass fiber (average fiber diameter: 0.6 μm) was 12% by weight.
And polyester fiber (fiber diameter 18μm, fiber length 5m
m) is 38% by weight, and a core-sheath type heat-fusible polyester fiber (fiber diameter: 14 μm, fiber length: 5 m) is used as a binder fiber.
m, a sheath melting point of 110 ° C.) and 50% by weight to prepare an aqueous slurry. From these slurries, a HEPA filter having a basis weight of 40 g / m ² was prepared using a mesh paper machine. It was set to 3.

Preparation Example 4 A mixture of 40 parts by weight of granular activated carbon, 40 parts by weight of granular zeolite adsorbent, and 20 parts by weight of a household alkaline detergent as a regenerating agent was used as a deodorant. As a binder for use, ethylene vinyl acetate resin powder having a softening point of 100 ° C. as a thermoplastic adhesive was used.

Preparation Example 5 A mixture of 40 parts by weight of granular activated carbon, 40 parts by weight of a granular zeolite adsorbent, and 20 parts by weight of sodium hydrogencarbonate as a regenerating agent was used as a deodorant. As a binder, ethylene vinyl acetate resin powder having a softening point of 100 ° C. as a thermoplastic adhesive was used.

Preparation Example 6 A mixture of 50 parts by weight of granular activated carbon and 50 parts by weight of a granular zeolite adsorbent was used as a deodorizing agent, and a total of 100 parts of the mixture was a thermoplastic adhesive as a binder for a deodorizing agent. 100 ° C. ethylene vinyl acetate resin powder was used.

Example 1 The deodorized mixed powder of Preparation Example 4 was sprayed on the substrate 1 of Preparation Example 1 at a rate of 100 g / m ² over a square area of 24 cm square. The squares on which the deodorized mixed powder is sprayed are arranged at a rate of 2 cm from the four sides through the portion where the deodorized mixed powder (the deodorizing agent) is not provided, and the squares on which the adjacent deodorized mixed powder is sprayed. In production, using a gravure type rotating roll,
The supply and non-supply of the deodorized mixed powder were determined by the arrangement of the concave portions of the gravure roll. Heating was performed from the side where the mixed powder was sprayed using a far-infrared heater having a surface temperature of 150 ° C. After the thermoplastic binder is plasticized, the heating is stopped, and the base material 2 of Preparation Example 2 is immediately superimposed on the deodorant spraying side of the base material B, sandwiched between two rolls, and pressed into a single unit. A shape-enclosed deodorizing sheet was manufactured. This was used as the regeneration type nitrogen oxide deodorizing filter of Example 1.

Example 2 Example 3 was repeated except that the substrate 2 of Preparation Example 2 was used instead of Example 2.
Example 1 except that the deodorized mixed powder of Preparation Example 5 was used instead of Preparation Example 4 as the deodorized mixed powder as the base material 3 of Example 1.
A regenerative nitrogen oxide deodorizing filter was obtained in the same manner as described above.

Example 3 The regeneration type nitrogen oxide deodorizing filter of Example 3 was pleated to obtain a regeneration type nitrogen oxide deodorizing filter unit of Example 3.

Example 4 The regeneration type nitrogen oxide deodorizing filter of Example 2 was pleated to obtain a regeneration type nitrogen oxide deodorizing filter unit of Example 4.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the deodorized mixed powder of Preparation Example 4 was replaced with the deodorized mixed powder of Preparation Example 6, and the spraying amount was 80 g / m ² . A nitrogen oxide deodorizing filter was obtained by the method.

Comparative Example 2 The nitrogen oxide deodorizing filter of Comparative Example 1 was pleated to obtain a nitrogen oxide deodorizing filter unit of Comparative Example 2.

As described above, the planar encapsulated deodorizing sheets obtained in Examples and Comparative Examples were evaluated for the nitrogen oxide deodorizing performance test and the regenerating performance after water immersion treatment by the following methods. Indicated.

[Nitrogen dioxide removal performance] The area of the specimen was 0.1
A sample of m ² is placed in a 1 m ³ stainless steel container while being attached to a commercially available air purifier “Daikin / Hikari Criere (ACEF-3DS)” and sealed. A gas was prepared so that the concentration of nitrogen dioxide in the container became 200 ppm. After confirming that the concentration of nitrogen dioxide in the container was constant, the air cleaner was operated, and the concentration of nitrogen dioxide in the container after 20 minutes was measured. Was evaluated.

[Regeneration performance after water immersion] After the nitrogen dioxide removal performance, the specimen was taken out of the air purifier and placed in 30 L of water.
Then, it was immersed for 100 minutes, dried with a hot air dryer at 100 ° C., and regenerated. The sample subjected to the regeneration treatment was again subjected to the same nitrogen dioxide removal test, and the regeneration performance was evaluated.

[0051]

[Table 1]

As shown in the examples, all of the samples using the deodorized powder mixed with the regenerating agent are superior in the initial deodorizing performance as compared with the sample of the comparative example not using the regenerating agent. I have. This means that there is an interaction effect between the treating agent and the adsorbent in the adsorbent layer.
Even after the regeneration treatment by immersion in water, the same level of performance as in the initial state was obtained, and this effect could be confirmed not less than the second time. As shown in the comparative examples, it can be seen that the performance of the sample using the regenerating agent hardly recovered after immersion in water.

[0053]

According to the present invention, in a nitrogen oxide deodorizing filter in which a deodorizing agent and a regenerating agent are enclosed in two base sheets, the initial nitrogen oxide deodorizing performance and the regenerating performance several times can be obtained. It is possible to provide a life-type regenerative nitrogen oxide deodorizing filter.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // B01J 20/34 F term (reference) 4C080 AA05 AA07 BB02 CC07 HH05 JJ05 KK08 LL02 MM02 MM03 MM04 MM05 MM31 4D048 AA06 AA22 AB03 BA05X BA06X BA11X BA14X BA15X BA16X BA41X BA45X BA46X BA50X BB04 BB08 BD06 CC40 EA04 4G066 AA05B AA13D AA14D AA43D AA61B BA01 CA02 CA28 DA03 FA20 FA22 GA11 GA31

Claims (4)

[Claims] 1. A planar encapsulated deodorizing filter comprising a base material A, a base material B and a deodorant layer enclosed therebetween, wherein the deodorant layer has a nitrogen oxide deodorant and a regeneration of the nitrogen oxide deodorant. A regenerative nitrogen oxide deodorizing filter containing a treatment agent. 2. The regeneration type nitrogen oxide deodorizing filter according to claim 1, wherein said nitrogen oxide regeneration treatment agent is potassium hydroxide, sodium hydroxide, calcium hydroxide, potassium carbonate, sodium carbonate, calcium carbonate, potassium hydrogen carbonate. A regenerative nitrogen oxide deodorizing filter comprising at least one selected from the group consisting of sodium hydrogen carbonate and calcium hydrogen carbonate. 3. A regenerative nitrogen oxide filter unit obtained by processing the regenerative nitrogen oxide deodorizing filter of claim 1 or 2 into a pleated shape. 4. The characteristics of the nitrogen oxide deodorizing agent whose effect is reduced by absorbing the nitrogen oxides by dissolving the encapsulated regenerating agent by washing the regenerative nitrogen oxide deodorizing filter of claims 1 to 3 with water. A deodorant treatment method for regenerating.