JP2000015020A - Air filter, its manufacture and high performance cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remover gaseous inorganic or organic impurities without releasing the gaseous organic or inorganic impurities and being safe by forming an inorganic matter layer by fixing respective powders of fraipontite mineral, manganese oxide and/or permanganate by a binder of an inorganic matter powder onto a surface of a substrate. SOLUTION: Aluminum made outer frames 15a, 15b, 15c, 15d being open in a circulating direction 13 of treating air are assembled around a honeycomb structured body 12, and a corrugated sheet and a plain sheet are laminated alternately parrallel to a circulation direction of air 13. Respective powders of fraipontite mineral, manganese oxide and/or permanganate are fixed by using powder of inorganic matter and a binder onto the whole of the honeycome structured by 12 to form an inorganic matter layer. Both of gaseous inorganic and organic impurities being causes for staining a surface of a substrate in an atmosphere can be removed by adsorption. Thereby, combustibles are not contained in the composition, prevention of disasters is excellent, gaseous inorganic and organic matter are not generated, and both of acidic and basic inorganic impurities and organic impurities can be collectively removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purification filter for removing gaseous inorganic impurities and gaseous organic impurities in an atmosphere, which is used in advanced cleaning equipment such as a clean room, a clean bench or a storage. Further, the present invention relates to a method for manufacturing such an air purification filter and an advanced cleaning device using the air purification filter.

[0002]

2. Description of the Related Art Today, advanced cleaning apparatuses are widely used for manufacturing semiconductors, LCD panels and the like. For example, a semiconductor manufacturing line from a bare wafer to the manufacture of 1MDRAM chips includes about 200 steps, and an LCD panel manufacturing line from elementary glass to a 9.4-type TFT includes about 80 steps. I have. In these production lines, it is difficult to continuously flow a wafer or a glass substrate through each process. For example, TFT-LCD
In a production line, a semi-finished substrate on which a single circuit has been formed in a previous process takes several hours to several tens of hours in a transport container (carrier) or a storage (stocker) before being transferred to a subsequent process.
Inside, it stands by while exposing to the atmosphere of the advanced cleaning equipment.

As described above, when a semiconductor substrate or an LCD substrate is left for a long time in a normal high-purity device atmosphere, gaseous impurities derived from the high-purity device atmosphere adhere to their surfaces. In recent years, silicon wafers and LCDs that exist in gaseous form in such advanced cleaning equipment and are used in semiconductor manufacturing
An acidic substance, a basic substance, an organic substance, a dopant, and the like, which adhere to the surface of a glass substrate used for panel production and affect the characteristics of a semiconductor or an LCD panel, are included.

An example of actual measurement of the concentration of chemical contamination contained in an ordinary clean room atmosphere in which no countermeasures against chemical contamination for gaseous impurities has been taken is as follows.
000 ppt, basic substance is 1,000 ppt-10,
000 ppt, organic matter is 1,000 ppt to 10,000
0 ppt and the dopant is about 10 to 100 ppt. US SEMATECH May 31, 1995
Technology Transfer announced today
# 95052812A-TR "Forecast of
Airborne Molecular Contami
nationLimits for the 0.25 M
iron High Performance Log
ic Process ”, the allowable concentration of chemical contamination required for the 0.25 μm process ('98 or later) (pp
According to t), for acidic substances, 180
Strict control of 5 ppt is required in the ppt and wiring process. In particular, sulfur oxide SOx reacts with ammonia gas in the air to produce silicon wafers, glass substrates, lenses,
A cloudy stain made of ammonium sulfate is generated on the surface of each of the mirror, hard disk, and magnetic disk, which adversely affects the manufacture of semiconductor elements, liquid crystal substrates, and magnetic recording components. For a basic substance, strict control of 1 ppb is required in a photolithography process. For the dopant, an extremely strict control of 0.1 ppt is required in the step before the gate oxide film. Strict control of organic substances is required at 1 ppb in the gate oxide film pre-process and 2 ppb in the wiring process.

[0005] Various advanced cleaning apparatuses for manufacturing semiconductor substrates and glass substrates, for example, various scale advanced cleaning apparatuses such as clean rooms, clean benches, clean chambers, various stockers for storing clean products, and mini-environments. In a local high-level cleaning apparatus referred to as an apparatus, impurities such as various gaseous acidic substances, basic substances, organic substances, and dopants are problematic. Of these, the dopant exhibits a chemical behavior similar to an acidic substance as a water-soluble boric acid compound or a phosphoric acid compound, and a filter capable of adsorbing and removing a gaseous acidic substance can also adsorb and remove the dopant to some extent. SEMATECH's Tech mentioned above
nology Transfer # 95052812A
According to -TR, regarding the control of gaseous contaminants in these advanced cleaning apparatuses, it is necessary to remove organic substances and dopants at one time in the gate oxide film pre-process, and collectively remove acids and organic substances at the wiring step.

Of these four types of chemical contaminants, three of the acidic, basic, and dopant are water-soluble, and are prone to ion exchange reactions and neutralization reactions. Therefore, as means for removing these three types of chemical pollutants from the air in a clean space, means for dissolving and removing them in an aqueous solution by wet cleaning (scrubber) and so-called chemical filters such as ion-exchange fiber and chemically impregnated activated carbon are used. There was an adsorption means. On the other hand, among the four types of chemical pollutants, many organic substances are hardly soluble in water.
As means for removing air from the clean space, there has been physical adsorption means using activated carbon.

Here, gaseous inorganic impurities such as acidic substances, basic substances, and dopants have been conventionally removed by three methods: wet cleaning, ion exchange fiber, and chemically impregnated activated carbon.

[0008] In the wet cleaning, an acidic substance,
Dissolve and remove basic substances and dopants. The simplest type of chemical filter using chemical-impregnated activated carbon is
2. Description of the Related Art A filling cylinder having a structure in which a predetermined case or the like is packed with granular carbon impregnated with a chemical is known. In particular, a chemical filter in which a chemical solution of potassium permanganate is impregnated into activated carbon to remove sulfur oxides SOx harmful to the manufacture of semiconductor elements, liquid crystal substrates, and magnetic recording components has been conventionally used.
Other types of chemical filters include a fibrous activated carbon impregnated with a chemical compound and an organic binder made of low-melting polyester or polyester non-woven fabric. Also known are block-shaped and sheet-shaped chemical filters which are firmly adhered to an adhesive with an adhesive.
Chemical filters that use ion-exchange fibers can convert various ions that are acidic and basic impurities contained in the air into non-woven fabrics, papermaking, felt, etc. based on acidic cation-exchange fibers and basic anion-exchange fibers. The ion exchange and removal are performed by a filter composed of

[0009]

In the wet cleaning, the initial cost of the spraying device is large, and the running cost due to the high pressure loss of the spray cannot be ignored. Furthermore, the advanced cleaning equipment used in the manufacture of semiconductor devices (LSIs) and liquid crystal displays (LCDs) is maintained at a temperature of 23 to 25 ° C and a relative humidity of 40 to 55%. When circulating while performing wet cleaning, it is necessary to perform temperature and humidity control again on the air after droplet spraying in order to cope with a temperature drop and humidity rise after droplet spraying. In addition, it is necessary to remove the liquid droplets remaining in the air after the liquid droplets are sprayed later in the spraying device (so-called carryover problem). further,
There is a problem specific to water treatment, such as treatment of a washing liquid circulated in a spray device, for example, prevention of generation of bacteria and concentration and separation of dissolved contaminants.

A so-called chemical filter using activated carbon or ion exchange fiber impregnated with a chemical has the following problems. First, as a problem common to both, for example, in the case of a clean room in which the ceiling surface is a clean air blowing surface, a chemical filter is arranged upstream of the particle removal filter mounted on the ceiling. This is a very effective means for removing gaseous impurities in the air atmosphere of a clean room. However,
Activated carbon is a flammable substance specified by the Fire Service Law, and ion-exchange fiber is also a material that is extremely easy to ignite. Therefore, from the viewpoint of disaster prevention, it is difficult to dispose a chemical filter using activated carbon or ion-exchange fiber on the ceiling.

Further, the chemical filter using activated carbon impregnated with a chemical has the following problems. That is, the conventional chemical filter of the filling cylinder type has a drawback that although the adsorption efficiency of impurities is high, the pressure loss (ventilation resistance) is high. In addition, conventional chemical filters in the form of felt or sheet have excellent air permeability, and the adsorption efficiency is not so inferior to that of the filled cylinder. Adhesives (eg, neoprene resin, urethane resin, epoxy resin, silicone resin, etc.) and sealing materials (eg, neoprene rubber, silicone rubber, etc.) used to fix the filter medium to the surrounding frame The gaseous organic impurities generated from the gas are contained in the air after passing through the chemical filter, which may adversely affect the manufacture of semiconductors.
In other words, the chemical filter using the felt- or sheet-shaped chemical-impregnated activated carbon is capable of removing chemical or acidic impurities in the clean room atmosphere, such as ppb-order trace impurities and ppt-order dopants. The gaseous organic impurities generated from the filter itself are mixed into the passing air. Further, there is a problem that sulfur dioxide gas cannot be sufficiently removed by a neutralization reaction with a conventional chemical filter containing a basic chemical or a metal. As a removal principle, only a chemical filter that has both a neutralization reaction and an oxidation reaction can sufficiently remove sulfite gas, and as a filter used to remove sulfur dioxide gas, a chemical filter in which a chemical solution of potassium permanganate is impregnated into activated carbon. Are also commercially available. However,
Potassium permanganate is a dangerous substance stipulated by the Fire Service Law, and it is difficult to install in a clean room because it causes bleaching and corrodes skin and clothes. This chemical filter has been attached to an external air conditioner in order to treat outside air taken into a clean room.

A chemical filter using a chemical-impregnated activated carbon is disclosed in Japanese Patent Application Laid-Open No. Sho 61-103518. A filter made by impregnating a base material made of urethane foam with an aqueous solution containing powdered activated carbon, an emulsion-type adhesive, and a solid acid, and then drying it. Desorption of gaseous organic substances occurs from the organic adhesive and also from the urethane foam itself.

A so-called chemical filter using ion exchange fibers has the following problems. That is, binders and adhesives used for processing non-woven fabrics, papermaking, felt, etc. based on ion exchange fibers into filter media having excellent air permeability, and used for fixing the filter media to the surrounding frame. Gaseous organic impurities generated from a sealing material or the like are included in the air after passing through the chemical filter, which may adversely affect semiconductor manufacturing. There is also dust from the filter media.

Japanese Patent Application Laid-Open No. 6-633 describes this type of filter.
33 and JP-A-6-142439. In the so-called chemical filter using ion exchange fibers used in the former air purification system, gaseous organic substances are desorbed from various additives contained in the constituent polymer fibers, and some of the ion exchange groups are removed. May be eliminated as a carboxylic acid or ammonia. In the latter case, the so-called chemical filter using ion-exchange fibers used in the method for purifying trace amounts of contaminated air in a clean room, desorbs gaseous organic matter from various additives contained in the nonwoven fabric of the polymer fiber as a constituent material. And some of the ion-exchange groups may be eliminated as sulfonic acid, carboxylic acid, phosphoric acid, ammonia or amine.

[0015] A filter for removing particulate impurities must be provided on the downstream side for dust generation from the chemical filter medium. When a filter for removing particulate impurities (a filter for removing particles) is provided downstream of the chemical filter, the filter for removing particulate impurities contains a material that generates gaseous organic impurities as a component. There is also a problem that the gas itself generates gaseous organic impurities.

Further, as a problem common to conventional chemical filters that use activated carbon impregnated with chemicals or ion-exchange fibers as an adsorption layer for removing inorganic impurities, when air containing both acidic and basic inorganic impurities is treated, Separately prepare an adsorbent material for removing acidic impurities and an adsorbent material for removing basic impurities, and use a mixture of these two adsorbent materials in a single adsorbent layer, or use them separately. There has been the complication that the adsorption layer for removing acidic impurities and the adsorption layer for removing basic impurities are manufactured and used in an overlapping manner.

In addition, when the clean room atmospheres of a plurality of processes are mixed without being separated, for example, when a plurality of processes are present in one large room clean room, the following inconvenience has occurred. By removing gaseous impurities such as acids, bases, and dopants in a process sensitive to inorganic impurities using a conventional chemical filter, the quality of the substrate was improved. In the process, gaseous organic impurities generated by the chemical filter itself did not affect the quality of the substrate. However, the same gaseous organic impurities caused surface contamination of the substrate in another process sensitive to the organic impurities in the same room, resulting in a decrease in quality. Therefore, in a large clean room where multiple processes coexist, a chemical filter that removes gaseous inorganic impurities such as acids, bases and dopants not only has excellent performance in removing these gaseous inorganic impurities, The filter itself must not generate gaseous organic impurities. There has been a strong demand for the development of a chemical filter which can remove not only gaseous inorganic impurities such as acids, bases and dopants but also gaseous organic impurities which cause substrate surface contamination in a clean room atmosphere.

If one kind of adsorbing material capable of removing both acidic and basic inorganic impurities at once can be used for the adsorbing layer for removing the inorganic impurities, the adsorbing layer volume can be reduced, the pressure loss can be reduced, and the adsorbing layer manufacturing cost can be reduced. Advantages such as reduction of the amount can be expected. In the case of treating air containing both inorganic impurities and organic impurities, conventionally, a chemical filter for removing organic impurities using activated carbon has been required separately from a chemical filter for removing inorganic impurities. If there is a chemical filter that can remove both inorganic impurities and organic impurities, advantages such as a reduction in filter volume, a reduction in pressure loss, and a reduction in filter manufacturing cost can be expected.

The following points should be noted when applying the chemical filter to an advanced cleaning device such as a clean room or a clean bench that can prevent acid / base contamination and organic contamination. (1) The chemical filter itself does not become a source of contamination of gaseous impurities or particulate impurities (a so-called secondary contamination source). (2) The pressure loss of the chemical filter is low. (3) High removal performance of gaseous impurities and long life. As described above, the conventional chemical filter cannot be said to satisfy these points.

Therefore, an object of the present invention is to provide a filter which is excellent in disaster prevention, does not desorb gaseous organic impurities and gaseous inorganic impurities from the filter itself, and has only a small amount of gaseous inorganic impurities contained in the air to be treated. It is another object of the present invention to provide an air purification filter capable of simultaneously removing gaseous organic impurities and preventing surface contamination of a substrate or the like due to the gaseous impurities, and an advanced cleaning device using the air purification filter. An object of the present invention is to provide an air purifying filter having both neutralizing action and oxidizing action with high efficiency even for sulfurous acid gas which has conventionally been difficult to remove by only the neutralizing action.
Sources of sulfur dioxide gas include those generated from sulfuric acid used as a chemical in the cleaning process inside the clean room and contaminate the surrounding atmosphere, and air pollutants and volcanic What was originally included as is considered. As an obstacle to the sulfurous acid gas, it reacts with the ammonia gas in the air and adversely affects the production of semiconductor elements, liquid crystal substrates, and magnetic recording components as described above.

[0021]

Means for Solving the Problems In order to solve the above-mentioned problems, the invention of claim 1 relates to a method in which a powder of frypontite mineral and a powder of manganese oxide and / or a powder of permanganate are replaced with a powder of an inorganic substance. An air purification filter characterized in that an inorganic material layer is formed by fixing the inorganic material layer to a surface of a support, using as a binder.

The invention of claim 2 provides a first inorganic material layer in which a powder of frypontite mineral is fixed with an inorganic powder as a binder, a powder of manganese oxide and / or a powder of permanganate. Are laminated with a second inorganic material layer to which an inorganic powder is fixed as a binder such that one of the first inorganic material layer and the second inorganic material layer is in contact with the surface of the support. An air purification filter characterized by the following.

Further, the invention of claim 3 provides a pellet of granulated flytonite mineral powder, manganese oxide powder and / or permanganate powder, and inorganic powder as a binder. An air purification filter characterized by being fixed to a surface.

Further, according to the invention of claim 4, a powder of manganese oxide and / or a powder of permanganate is provided around the first pellets obtained by granulating a powder of frypontite mineral using an inorganic powder as a binder. Around the second pellet coated with the powder of the inorganic material as a binder, or the first pellet obtained by granulating the powder of manganese oxide and / or the powder of permanganate with the inorganic powder as a binder Further, an air purification filter is characterized in that a second pellet coated with a powder of frypontite mineral and a powder of an inorganic substance as a binder is fixed to the surface of a support.

In the air purifying filter according to any one of the first, second, third and fourth aspects, the support is, for example, a honeycomb structure as described in the fifth aspect. The honeycomb structure according to the fifth aspect is preferably a structure containing inorganic fibers as an essential component. In addition, a honeycomb structured support reduces ventilation resistance. If the support is made of a ceramic material such as inorganic fibers, it has a hard surface and is suitable for installation and maintenance. The adsorbing layer fixed to this is integrated with the support, and generates a very small amount of dust as compared with a conventional chemical filter using activated carbon or ion exchange fiber impregnated with a chemical. In addition to this support, the powders of the adsorbents frypontite mineral and manganese oxide are originally inorganic substances, and the binder used to fix them on the surface of the support is also made of inorganic powder. There is no desorption of gaseous organic matter from the material constituting the air purification filter of the present invention. In this specification, the term “honeycomb structure” includes not only a so-called honeycomb structure but also any structure in which a cross section has a lattice shape, a wavy shape, or the like, and in which air can pass through cells serving as elements of the structure. In the present invention, the support is not limited to the honeycomb structure. A three-dimensional network structure such as rock wool can also be suitably used as a support. In this case, as will be described later, it is preferable to fix the adsorbent of the present invention, i.e., the powder of the pontoite mineral and the powder of manganese oxide, not only in the plane direction but also in the depth direction of the network structure. The method of adhering the adsorbent to the surface of the support may be a method of adhering with an inorganic powder binder, or a method using the adsorbent powder of frypontite mineral and the powder of manganese oxide as a binder using the inorganic powder as a binder. There is a method in which granules are formed into pellets, and the pellets are adhered to the surface of the support.

Further, the invention of claim 6 provides a pellet obtained by granulating a powder of a flypontite mineral and a powder of a manganese oxide and / or a powder of a permanganate using an inorganic powder as a binder. A second pellet in which manganese oxide powder and / or permanganate powder is coated with the inorganic powder as a binder around the first pellets obtained by granulating the powder of pontitite mineral with the inorganic powder as a binder; Pellets or a powder of manganese oxide and / or a powder of permanganate are wrapped around the first pellets granulated using inorganic powder as a binder.
An air purification filter, characterized in that a casing is filled with second pellets coated with a powder of frypontite mineral using an inorganic powder as a binder.

Here, the frypontite mineral is a 1: 1 type whose composition formula is represented by the following formula (1) or (2).
(Double structure) A metal salt of aluminosilicate belonging to the serpentine subgroup clay mineral. As shown in FIG. 1, it has a double structure crystal in which one surface is solid basic and the other surface is solid acidic.

[0028]

Embedded image

Each surface of solid basic and solid acidic forms an adsorption site for each of acid and base. Noriyuki Takahashi, Masanori Tanaka, Teiji Sato, "Structure of Synthetic Flypontite", The Chemical Society of Japan, 1991, No. 7, p. 962
According to No. 967, the thickness of the unit layer of frypontite is 7.1 angstroms.

When the frypontite mineral is used to remove gaseous acidic impurities and gaseous basic impurities in the atmosphere as in the present invention, a fly having a two-layer structure is used as shown in FIG. The unit layer or at most several layers of pontite are dispersed in the space one by one without overlapping each other via, for example, inorganic fine particles, and the air to be treated is dispersed in the unit layer of each frypontite or It is essential to contact the adsorption sites present on the surface of several layers of the laminate. Therefore, the unit layer or several layers of fly pontites are uniformly distributed inside the porous structure (for example, the inorganic material layer of the present invention) through which air can easily flow, and the air to be treated is uniformly distributed. By entering and exiting through the pores of the porous structure, it is effectively contacted with adsorption sites existing on the surface of microcrystallites of frypontite (for example, a disk having a thickness of several tens angstroms and a diameter of 100 angstroms to 1 μm). Thereby, gaseous acidic impurities and gaseous basic impurities can be removed.

The microcrystallites of frypontite do not have micropores or mesopores which are involved in the physical adsorption of gaseous organic impurities, so that they can adsorb gaseous organic impurities.
No ability to remove. In addition, since the frypontite mineral powder has no self-bonding property, a binder must be added in order to form the frypontite mineral powder into pellets or to fix it to the surface of the support in a layered manner. .

In the air purifying filters according to the first to sixth aspects, the inorganic material layer, the first and second inorganic material layers, the pellets, or the first and second pellets (hereinafter referred to as “inorganic material layer and the like”). ), The powder of frypontite mineral,
A gap serving as an air hole is formed at a position where the fine particles of the manganese oxide powder or the inorganic binder powder are adjacent to each other. It enters the inside of the layer or the like, and conversely, goes out from the inside of the inorganic material layer or the like to the outside. When passing through the inside of the inorganic material layer and the like, acidic and basic gaseous impurities in the air are adsorbed and removed by the frypontite mineral, and the semiconductor, LCD panel, hard disk, Sulfur oxides SOx harmful to the manufacture of magnetic disks and the like (hereinafter referred to as "precision electronic components and the like") are removed. In addition, DOP and DB can be selected by appropriately selecting the type of the inorganic powder used as the binder having pores in the micropore region or the mesopore region.
Since gaseous organic substances such as P, BHT, and siloxane can be adsorbed and removed, most of these chemical contaminants can be captured even in an atmosphere in which various kinds of chemical contaminants related to the surface contamination of the substrate are mixed. In particular, in the air purifying filter of the second and fourth aspects, if the layer containing the manganese oxide powder is placed outside, the inorganic material layer composed of the binder of the manganese oxide powder and the inorganic powder on the outside is used. It has an effect of preventing dust generation from an inorganic material layer formed of a binder of the powder of the fly pontit mineral and the powder of the inorganic substance at the bottom.

In the air purifying filter according to the second, fourth, and sixth aspects, since an inorganic substance such as silica having a high affinity (adsorption rate) with the gaseous boron compound exists in both of the two inorganic material layers, the silica is used. And the like, the total amount of inorganic substances, such as, increases, the change over time in the removal efficiency of the gaseous boron compound is small, and the gaseous boron compound can be removed for a relatively long time.

In the air purification filter of the present invention, it is preferable that the outer frame and other accessory parts are also made of only a material that does not generate gaseous organic impurities, and are made of only a material that does not contain combustible materials.

In the air purifying filters according to the first to sixth aspects, as described in the seventh aspect, the manganese oxide is composed of trimanganese tetroxide (Mn ₃ O ₄ ) and dimanganese trioxide (Mn ₂ O ₃ ). , Manganese dioxide (MnO ₂ ). For example, sulfur dioxide, a typical sulfur oxide, does not readily undergo a neutralization reaction with zinc (or magnesium) as it is. However, if sulphite gas is oxidized by manganese oxide and converted into sulfuric acid, neutralization reaction with zinc (or magnesium) in the frypontite mineral easily occurs, so that it can be removed. In addition, among manganese oxides, MnO has a weak oxidizing power, and thus is difficult to use in the present invention. In addition, 7 oxidation 2
Manganese (VII) (Mn ₂ O ₇ ) is difficult to use in the present invention because of its detection for disaster prevention and the like.

Here, the case where the sulfur dioxide gas SO ₂ is removed by manganese dioxide (MnO ₂ ) will be described as follows. That is, first, sulfur dioxide gas in the air dissolves in the water adsorbed in the honeycomb pores according to the following equation. SO ₂ + H ₂ O → ← H ₂ SO ₃

Next, due to the synergistic effect of the reducing action of sulfurous acid and the oxidizing action of manganese dioxide, sulfurous acid is immediately oxidized,
It becomes sulfuric acid according to the following formula. H ₂ SO ₃ +2 MnO ₂ → H ₂ SO ₄ + Mn ₂ O ₃

According to manganese oxide other than manganese dioxide (MnO ₂ ), sulfuric acid is produced according to the following reaction formula. H ₂ SO ₃ + Mn ₃ O ₄ (trimanganese tetroxide) → H ₂ SO ₄ + 3MnO H ₂ SO ₃ + Mn ₂ O ₃ (dimanganese trioxide) → H ₂ SO ₄ + 2MnO If manganese oxide has only an oxidizing action, It also has the function of oxidizing sulfurous acid as a catalyst to convert it to sulfuric acid. When manganese oxide functions as a catalyst, the oxidation number of manganese does not change.

Next, sulfuric acid reacts with zinc in the frypontite mineral according to the following formula to produce zinc sulfate. Zn + H ₂ SO ₄ → ZnSO ₄ + H ₂ ↑ The above reaction formulas for manganese dioxide can be summarized as follows. SO ₂ + H ₂ O + 2MnO ₂ + Zn → ZnSO ₄ + Mn
₂ O ₃ + H ₂ ↑

In this way, the sulfurous acid gas in the air is removed as a salt with zinc and removed, and an environment suitable for manufacturing precision electronic parts and the like can be obtained. Note that manganese dioxide is insoluble in water and is preferably bulk particles having a particle size of several microns.

Further, MnO₂→ Mn₂O₃Change occurs
By doing so, Mn₂O₃Is bulk MnO₂Of particles
MnO covering the surface₂Inhibits the oxidation reaction of
There is a concern that the ability to adsorb sulfur oxides
To be reminded. However, Mn₂O ₃Is soluble in acid, sulfuric acid
Constantly with MnO₂Thought that a fresh surface of will appear
There is no such concern. The above action is a reaction
Although omitting the formula in detail, manganese dioxide
(MnO₂) Instead of trimanganese tetroxide (Mn
₃O₄), Dimanganese trioxide (Mn₂O₃)
The same is true in the case, and there is no such concern.

In the air purifying filter according to any one of the first to seventh aspects, as described in the eighth aspect, the permanganate comprises M ^I MnO ₄ (M ^I : alkali metal), M
^II (MnO ₄ ) ₂ (M ^II : alkaline earth metal). Due to the synergistic effect of the oxidizing action of these permanganates and the reducing action of sulfurous acid, sulfurous acid is immediately oxidized and converted to sulfuric acid, and in the same manner as described for manganese oxide, zinc and magnesium are mixed. It is possible to cause a summation reaction and to remove it.

In the air purifying filter according to any one of claims 1 to 8, the inorganic substance may be talc, kaolin mineral, bentonite, diatomaceous earth, silica, alumina, or a mixture of silica and alumina. , Aluminum silicate, activated alumina, porous glass, hydrated magnesium silicate clay mineral with ribbon-like structure, activated clay,
It is preferred that it be made of at least one kind of activated bentonite. For example, silica gel is used as silica.
As the alumina, for example, alumina gel is used. As the mixture of silica and alumina, for example, a mixed gel of silica gel and alumina gel is used.

Further, in the above-mentioned inorganic substance, 15 to 300
Preferably, the total volume of the pores distributed in the range of Angstroms is 0.2 cc / g or more per weight, or the specific surface area of the pores is 100 m ² / g or more. When the above inorganic substances are selected, the inorganic powder contained in the inorganic material layer or pellets used as the binder for the powder of the frying-pontite mineral or the powder of the manganese oxide or permanganate may be used as the powder of the frying-pontite mineral. Ability to mechanically fix powder of manganese oxide or manganese oxide or permanganate to the surface of the support, or as a binder when granulating powder of frypontite mineral or manganese oxide into pellets And the porosity that allows the gas to be treated to easily reach the acidic and basic points present on the surface of the crystal layer of the frypontite mineral and the surface of the manganese oxide or permanganate particles. Have the same structure.

Here, for the inorganic powder used as the binder, the total volume of pores distributed in the range of 15 to 300 angstroms and the specific surface area of the pores of the inorganic substance were determined as follows:
Table 1 shows the results measured by the gas adsorption method.

[0046]

[Table 1]

Incidentally, silica gel was used as a powder sample as silica. Alumina gel was used as a powder sample for alumina. As a mixture of silica and alumina, a mixed gel of silica gel and alumina gel was used as a powder sample. 15 ~
The reason for focusing on pores distributed in the range of 300 Å is that pores having a size in this range excel at physical adsorption of gaseous organic impurities. The air to be treated is treated with fine crystallites of pontoonite and manganese oxide fine particles through the air holes in the gap formed adjacent to the powder of pontoite mineral, manganese oxide or permanganate, and the inorganic powder used as a binder. Alternatively, the gaseous acidic impurities and gaseous basic impurities can be easily reached to the surface of the permanganate fine particles to remove them. At this time, gaseous organic impurities are removed by physical adsorption on the surface of the pores having the size in the above range existing on the surface of the inorganic powder used as the binder. In addition to the removal of gaseous acidic impurities and gaseous basic impurities, which is the main object of the present invention, it is possible to realize the simultaneous removal of gaseous organic impurities as a secondary effect of the pores of the inorganic powder used as the binder.

The specific surface area and pore volume of the binder of the group (I) shown in Table 1 are considerably larger than those of the binder of the group (II). Therefore, the physical adsorption capacity of the gaseous organic impurities is as follows.
It is considerably better than the binder of I). Binders such as talc, kaolin mineral and bentonite of the group (II) place importance on air permeability, and are formed in the gap between adjacent binder fine particles or between the adjacent binder fine particles and the adsorbent fine particles carried on the support. The primary size of the vent will be over 500 angstroms. In other words, the air holes are macro holes that have very good air permeability but are unlikely to cause physical adsorption. In addition, there are not many pores that easily cause physical adsorption on the surface of the binder fine particles such as talc, kaolin mineral and bentonite. The binders of the group (II) are used merely for mechanically supporting the powder of the frypontite mineral or the powder of manganese oxide or permanganate to be supported on the surface of the support, in this case, In order to increase the ability to adsorb inorganic impurities, increase the loading of frying-ponite mineral powder and manganese oxide or permanganate powder as much as possible, and use the binder for frying-ponite mineral and manganese oxide or permanganate. The content should be as small as possible. However, if the content ratio of the binder is too low, the adhesion of the powder of the frypontite mineral or the powder of the manganese oxide or permanganate to the surface of the support becomes incomplete and causes peeling and dust generation. For example, even when a binder of bentonite is added to the frypontite mineral powder and silica is mixed as a fixing aid and then fixed to the support, the content of the frypontite mineral powder in the inorganic material layer on the support surface ( (By weight) exceeds 75%, the mechanical strength of the inorganic material layer on the surface of the support becomes weak, and the inorganic material layer cannot be put to practical use. That is, the binder of the group (II)
Carrying capacity of frying-pontite mineral powder or manganese oxide or permanganate powder, and the target gas can easily reach the surface of the supported frying-pontite mineral powder or manganese oxide or permanganate powder Such excellent ventilation capacity is required, and the ability to adsorb gaseous organic impurities is not required. On the other hand, when the binder of the group (I) is used, the fine particles are formed in the gap between adjacent fine particles of the binder or between the fine particles of the adjoining binder and the fine particles of the flypontite mineral or manganese oxide or the fine particles of permanganate. The vent holes are the same as those of the group (II). Therefore, since the gas to be treated has excellent air permeability so that the gas to be treated can easily reach the surface of the powder of the frypontite mineral or the powder of the manganese oxide or permanganate, the surface of the fine crystallite of the frypontite mineral powder is The characteristics that gaseous acidic impurities and gaseous basic impurities are removed at existing adsorption sites and that sulfurous acid gas is oxidized on the surface of manganese oxide fine particles and changes into sulfuric acid are the same as those of the binder of group (II). It is exhibited in.

The ease of physical adsorption of gaseous molecules is in the order of micropores, mesopores, and macropores, and it is said that macropores hardly participate in physical adsorption. In the binders of the group (I), the pores which are liable to cause physical adsorption on the surface of the binder fine particles themselves, that is, micropores having a pore size of 20 Å or less,
Since there are mesopores, which are pores having a size of 0 Å to 500 Å, gaseous organic impurities that can contaminate the substrate surface, such as DOP, DBP, BHT, and siloxane, which cannot be adsorbed by the frypontite mineral, The binder particles are adsorbed and removed on the surface of the binder particles themselves by physical adsorption.

In the case where the binder of the group (I) is used, the content ratio (weight basis) of the powder of frypontite mineral or the powder of manganese oxide or permanganate in the inorganic material layer on the surface of the support is also considered. Has an upper limit. For example, when the frypontite mineral powder is fixed to a support using silica gel as a binder, when the content (by weight) of the frypontite mineral powder in the inorganic material layer on the support surface exceeds 72%, the inorganic material layer is immobilized. Became weak in mechanical strength and could not withstand practical use.

According to a tenth aspect, at least one of the inorganic material layer, the first inorganic material layer, the second inorganic material layer, the pellet, the first pellet, and the second pellet. May be mixed with an inorganic fixing aid.
In this case, it is preferable that the inorganic fixing aid contains at least one of sodium silicate, silica and alumina. As silica, for example, silica sol is used. For example, alumina sol is used as alumina.

According to a twelfth aspect of the present invention, a support is provided in a suspension in which powder of frypontite mineral, powder of manganese oxide and / or powder of permanganate, and powder of an inorganic substance as a binder are dispersed. A method for producing an air purification filter, comprising drying the support after impregnation and fixing an inorganic material layer on the surface of the support.

According to a thirteenth aspect of the present invention, the support is impregnated with a suspension in which the powder of the frypontite mineral and the inorganic powder as the binder are dispersed, and then the support is dried to form a support. A first inorganic material layer is formed on the surface, and the support on which the first inorganic material layer is formed is further combined with a manganese oxide powder and / or a permanganate powder and an inorganic powder as a binder. After impregnating the dispersed suspension,
After drying to form a second inorganic material layer on the surface of the first inorganic material layer, or after forming the second inorganic material layer on the surface of the support, the second inorganic material layer is further formed. Forming the first inorganic material layer on the surface of
This is a method for manufacturing an air purification filter.

According to the method for manufacturing an air purifying filter according to the twelfth or thirteenth aspect, the air purifying filter can be composed only of a material that does not generate gaseous organic impurities. Further, the air purification filter is substantially composed of only a material that does not contain combustibles. In the manufacturing methods of claims 12 and 13, for example, silica gel is used as silica. As the alumina, for example, alumina gel is used. As the mixture of silica and alumina, for example, a mixed gel of silica gel and alumina gel is used. When forming an inorganic material layer on the surface of the support, further forming a second inorganic material layer on the first inorganic material layer, or forming a first inorganic material layer on the second inorganic material layer When forming a sol, the inorganic material layer and the first and second inorganic material layers each contain an inorganic adhesive agent when the suspension is mixed with an inorganic adhesive agent in a sol state. become.

According to a fourteenth aspect of the present invention, there is provided an advanced cleaning apparatus provided with a circulation path for circulating air in a space where a clean atmosphere is required.
The air purification filter according to any one of 4, 5, 6, 7, 8, 9, 10, and 11, and the removal of particulate impurities upstream of the space and downstream of the air purification filter. It is an advanced cleaning device characterized by a filter. According to the advanced cleaning device of the present invention, the gaseous acidic impurities and gaseous basic impurities in the air circulating in the advanced cleaning device and, in some cases, the gaseous organic impurities are also removed. It is possible to prevent surface contamination due to the atmosphere of the substrate surface handled in the processing space in the advanced cleaning apparatus.

The high-purity cleaning apparatus according to the fourteenth aspect is excellent in disaster prevention because it does not use activated carbon or ion-exchange fiber, which is a combustible material.
The air purification filter and the filter for removing particulate impurities can be arranged on the ceiling of the space.

[0057]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an air purification filter and a method for manufacturing the same according to the present invention will be described below in detail with reference to the accompanying drawings. In the following description, the term "filter" refers to a filter for removing gaseous impurities, and the term "filter for removing particles" refers to a filter for removing particles.

FIG. 3 is a schematic exploded view of the filter 1 according to the embodiment of the present invention. As shown in the figure, a thin sheet 1 having no unevenness is provided between adjacent corrugated sheets 10.
1 is provided. The outer frames 15a, 15b, 15c, 15c are made of aluminum so as to open around the honeycomb structure 12 in the flow direction of the processing air (the direction indicated by the white arrow 13 in the figure).
Assemble 15d, corrugated sheet 10 and thin sheet 11
Are alternately stacked substantially parallel to the air flow direction 13. The outer shape and dimensions of the filter 1 can be arbitrarily designed according to the installation space.

Then, the entire honeycomb structure 12 is
(1) A configuration in which an inorganic material layer is formed by fixing powdery frypontite mineral and manganese oxide powder and / or permanganate powder as an inorganic powder as a binder, or (2) the honeycomb structure 12 A first inorganic material layer is formed by adhering a powder of frypontite mineral as a binder with the inorganic powder as a binder. (3) the honeycomb structure 1 is fixed to the surface of the first inorganic material layer to form the second inorganic material layer.
2, a manganese oxide powder and / or a permanganate powder is fixed to the inorganic powder as a binder to form a second inorganic material layer, and the flypontite mineral powder is replaced with the inorganic powder. Is used as a binder to adhere to the surface of the second inorganic material layer to form the first inorganic material layer, or (4) the fly pontitite mineral powder and the manganese oxide powder And / or permanganate powder is fixed to pellets obtained by granulating with inorganic powder as a binder, or (5) fly ponite mineral powder is applied to the entire honeycomb structure 12;
A structure in which manganese oxide powder and / or permanganate powder is coated with second pellets coated with inorganic powder as a binder around the first pellets obtained by granulating inorganic powder as a binder. , (6) Manganese oxide powder and / or permanganate powder are granulated on the entire honeycomb structure 12 around the first pellets obtained by granulating the inorganic powder as a binder. The powder is fixed to a second pellet coated with an inorganic powder as a binder.

Here, manganese oxide means trimanganese tetroxide (Mn ₃ O ₄ ), dimanganese trioxide (Mn)
₂ O ₃ ) or manganese dioxide (MnO ₂ ). Furthermore, ^{_{permanganate, M I MnO 4 (M I}} : alkali ^{_{metal), M II (MnO 4)}} 2: it is preferable to either of the ^{(M II} alkaline earth metals). Also,
The inorganic substances used as the binder include talc, kaolin mineral, bentonite, diatomaceous earth, silica, alumina, a mixture of silica and alumina, aluminum silicate, activated alumina, porous glass, hydrated magnesium silicate clay mineral having a ribbon-like structure, It is preferable to use at least one inorganic powder of activated clay and activated bentonite.
As silica, for example, silica gel is used.
As the alumina, for example, alumina gel is used. As the mixture of silica and alumina, for example, a mixed gel of silica gel and alumina gel is used. Hereinafter, these inorganic powders used as binders are simply referred to as inorganic binders.

Here, an example of a method for manufacturing the filter 1 will be described.
I will tell. First, inorganic fibers (ceramic fibers, glass fibers)
Fiber, silica fiber, alumina fiber, etc.) and organic materials (pal
Mixture of molten vinylon) and calcium silicate
The materials are mixed in an equal weight of 1: 1: 1 and wet papermaking is used.
The paper is formed to a thickness of about 0.3 mm. In addition, calcium silicate
Instead of magnesium silicate
Using fibrous crystalline clay minerals such as
May be used. This sheet is waved by a corrugator.
Shaped and finished corrugated sheet 10 is made of similar material
Adhesively bonded to a thin sheet 11 made into a thin sheet shape
Then, a honeycomb structure 12 as shown in FIG. 3 is obtained. this
The honeycomb structure 12 is placed in an electric furnace at about 400 ° C. for 1 hour.
Heat treatment for about an hour to remove all organic components
You. Surface of honeycomb structure after removal of organic components
Innumerable micron-sized depression holes remain in the
It is possible to manufacture a porous honeycomb structure 12 having holes as holes.
Can be. Later, the cavities are filled with adsorbent or inorganic binder.
The fine particles will get stuck. Next, fly tie
Mineral powder and manganese oxide powder and / or
Suspension in which the powder of ganates and the inorganic binder are dispersed
Then, the honeycomb structure 12 is immersed for several minutes and then pulled up.
And dried by heat treatment at about 300 ° C for about 1 hour.
As shown in FIG.
Tight mineral powder and manganese oxide powder and / or excess
Fixing the ganganate powder using an inorganic binder
The filter 1 is obtained by forming the mechanical material layer 20.
be able to. The suspension contains an inorganic fixing aid, for example,
At least one of sodium silicate or silica or alumina
Can also be mixed. In this case, as silica
For example, silica sol is used. Examples of alumina
For example, alumina sol is used. Role of inorganic fixing aid
The percentages are frypontite mineral powder and manganese oxide powder.
Powder and / or permanganate powder and inorganic binder
The surface of the honeycomb structure 12 (the element of the honeycomb structure 12
Firmly fixed to the inner surface of the cell (including the following)
It functions as an auxiliary agent for The resulting file
Filter 1 does not contain flammable materials in its constituent materials and is safe for disaster prevention.
Significantly increase. When the filter is heat treated,
Gaseous organics that cause surface contamination contained in raw materials
Since all impurity components are desorbed and removed, the filter 1
No gaseous organic impurities are generated from the body. Processing sky
The cross-sectional shape of the space through which the air passes is half-moon
The shape is not limited to the shape, and may be any shape. Note that excessive
Manganates are M^IMnO₄(M^I: Alkali gold
Genus), M ^II(MnO₄)₂(M^II: Alkaline earth gold
Genus). However, it is an alkali metal
Potassium, rubidium and cesium permanganate is water
Solubility in water is relatively small, about 11g / 100g water (25 ℃)
However, other permanganates are well soluble in water. Well in water
Of soluble permanganate powder and frypontite mineral
A honeycomb structure is added to a suspension of powder and an inorganic binder.
A filter manufactured by immersing the structure 12 and pulling it up and drying it
In 1, the permanganate contained in the inorganic material layer 20 is not
Can no longer maintain the morphology of the particles.
Entering the gap formed in the adjacent part of the inorganic binder powder
Is fixed. Powder and acid of frypontite mineral
Instead of manganese iodide powder,
Powder and permanganate powder may be used.

FIG. 5 is an enlarged sectional view of a part of the inorganic material layer 20 shown in FIG. The gas to be treated is obtained from the surface of the inorganic material layer 20 (the contact surface with the gas to be treated) from the powder of frypontite mineral, the powder of manganese oxide and / or the powder of permanganate, and the fine particles of the inorganic binder. The gas enters the inside of the inorganic material layer 20 or goes out of the inside of the inorganic material layer 20 so as to pass through the ventilation hole formed therebetween. At that time, gaseous acidic impurities and gaseous basic impurities are removed from the powder of the frypontite mineral, and molecules of the gaseous organic impurities enter the pores suitable for physical adsorption existing on the surface of the binder fine particles. Removed. In this case, due to the presence of manganese oxide and / or permanganate, sulfur oxides such as sulfurous acid gas are also removed by the frypontite mineral.

Next, another method of manufacturing the filter 1 will be described. Until the honeycomb structure 12 is manufactured, the manufacturing method is the same as the above-described manufacturing method, and a description thereof will be omitted. In this production method, pellets produced by granulating a powder of fly pontoite mineral, a powder of manganese oxide, and / or a powder of permanganate are adhered to the surface of the honeycomb structure 12 with an adhesive.
When granulating the powder of frypontite mineral and the powder of manganese oxide and / or permanganate, the powder of frypontite mineral and the powder of manganese oxide and / or permanganate are mixed. When an inorganic binder is mixed with an appropriate amount of water and an inorganic fixing aid mixed therein, clay-like viscosity and plasticity are exhibited and granulation becomes possible.
In this case, for example, city water is mixed with both the powder of the frypontite mineral, the powder of the manganese oxide and / or the powder of the permanganate, and the powder of the inorganic substance to form a clay.
Granulate into pellets of about 0.8 mm with a granulator. The pellets can be fixed to the surface of the honeycomb structure 12 by spraying the support using a high-speed air onto a support to which an inorganic and nonflammable adhesive has been attached in advance. The types of the inorganic binder and the inorganic fixing aid are the same as those in the above-described production method.

FIG. 6 shows a case where inorganic powder is used as a binder.
Pellets 21 obtained by granulating powder of frypontite mineral, powder of manganese oxide and / or powder of permanganate
FIG. 3 is a partially enlarged cross-sectional view of a filter 1 having a configuration in which is fixed to the surface of a honeycomb structure 12. The pellets 21 are fixed to the entire surfaces of the corrugated sheet 10 and the thin sheet 11 with no corners using a nonflammable adhesive. In this embodiment, the processing air passes through a thin cylindrical portion 17 having a pseudo-half moon cross section. Then, the honeycomb structure 12 to which the pellets 21 are fixed is placed in an electric furnace and subjected to a heat treatment at about 100 ° C., which is lower than the heat resistant temperature of the adhesive, for about 2 hours. The filter 1 can be manufactured by desorbing and removing all the gaseous organic impurity components. The filter 1 thus manufactured can also adsorb and remove gaseous acidic impurities, gaseous basic impurities, and gaseous organic impurities as in the case described above with reference to FIG. 5, and can remove manganese oxide and / or permanganate. Due to the presence of sulfur dioxide, sulfur oxides such as sulfurous acid gas can also be removed by the frypontite mineral.

As shown in the AA cross section and the BB cross section in FIG. 7, the frypontite mineral is mainly formed by an inorganic binder having pores in a mesopore region or a micropore region.
A filter 1 'is formed by molding manganese oxide powder and / or permanganate powder into a pellet 21 and filling the pellet 21 into a double cylindrical casing 22 having a large number of vents 23 on the side surface. By doing so, the object of the present invention can be achieved. The processing air flows in from the inner cylinder of the casing 22 and the pellets 21 in the casing 22.
After passing through the packed layer of the casing 22, it passes through the space between the outer cylinder of the casing 22 and the outer cylinder 24 and exits. The flow direction of the processing air is indicated by an arrow 13. The shape of the casing 22 is not limited to the double cylindrical shape as shown in FIG.
As another form of the casing, for example, a metal flat plate having a large number of vents is formed into a pleated shape, and two pleated shaped plates are arranged in parallel at a predetermined interval.
A structure in which the parallel space portion is filled with pellets is also conceivable. Such a casing resembles the shape of HEPA or ULPA which is a filter for removing particles, and can process a large air volume with a low ventilation resistance by increasing the ventilation area.

Here, a method of synthesizing microcrystallites of frypontite having several to several tens of unit layers of frypontite having a two-layer structure shown in FIG. 1 on an industrial scale is known as a hydrothermal method. And Noriyuki Takahashi, Masanori Tanaka, Teiji Sato, "Synthesis of Frypontite", The Chemical Society of Japan, 199
0, No. 4, p. Details are described in 370-375.

For example, the thus-obtained disk-shaped synthetic frypontite microcrystal powder having a thickness of several tens of angstroms and a spread diameter of 100 angstroms to 1 μm is converted into a manganese oxide powder and / or a permanganate powder. Along with the powder, an inorganic binder of powdered acid-treated montmorillonite (activated clay) having a particle diameter of several tens of nm is mixed and fixed to the surface of the honeycomb structure 12, or the mixture is formed into pellets 21 to form a honeycomb structure. The filter 1 of the present invention is fixed to the surface of the filter 12 or filled in the casing 22.
And 1 '. Montmornite is Al ₄ Si produced in Montmorion, France.
₈ (OH) ₄ .nH ₂ O is a name given to a clay mineral having a chemical composition of: When montmorillonite is treated with an acid, the pore volume is 15 to 300 angstroms, the pore volume is about 0.37 cc / g, and the specific surface area. Is about 300 m ² / g. The ratio of the pore volume in the range of 40 Å to 600 Å of the pore volume in the whole pore volume is as high as 22%, and the acid-treated montmorillonite (activated clay) is used as a binder for the powder of flypontite mineral or the powder of manganese oxide. Utilization makes it possible to physically adsorb gaseous organic impurities, which cannot be adsorbed by the powder of frypontite mineral, manganese oxide, or permanganate, into the pores of the binder.

Among the binders of the group (II) in Table 1, talc and kaolin minerals have a large crystallite size and a large volume of macropores, but have a small internal surface area and volume of micropores and mesopores. ， Physical adsorption ability is small. Among the binders in the group (II), bentonite also has a large volume in the macropore region, but has a small internal surface area and volume in the micropore region and the mesopore region, and has a small physical adsorption capacity. On the other hand, among the binders of the group of (I) in Table 1,
For example, the pores of sepiolite, a hydrated magnesium silicate clay mineral with a ribbon-like structure, consist of 10 Å micropores and 200 Å mesopores.
The internal surface area and volume of the micropore region and the mesopore region are large and the physical adsorption capacity is large. Binders of the group (I), namely diatomaceous earth, silica (silica gel), alumina (alumina gel), a mixture of silica and alumina (a mixed gel of silica gel and alumina gel), aluminum silicate, activated alumina, porous glass, ribbon Hydrated magnesium silicate clay mineral with a flake-like structure, acid-treated montmorillonite (activated clay),
Activated bentonite inorganic powder has a large physical adsorption capacity. As shown in Table 1, all of the inorganic substances of the group (I) have a pore volume per unit weight of 0.1 Å distributed in a range of 15 Å to 300 Å.
2 cc / g or more, or a specific surface area of 100 m ²
/ G or more. Of course, the inorganic powder of the group (I) can be suitably used as a binder for the second inorganic material layer formed on the first inorganic material layer containing the powder of frypontite mineral, as described later. .

Next, another method of manufacturing the filter 1 will be described. Until the honeycomb structure 12 is manufactured, the manufacturing method is the same as the above-described manufacturing method, and a description thereof will be omitted. First, the honeycomb structure 12 is immersed for several minutes in a suspension in which a powder of frypontite mineral and an inorganic binder are dispersed, and then dried by heat treatment at about 300 ° C. for about 1 hour to form a first inorganic material. A layer 25 is formed. Next, a suspension of manganese oxide powder and / or permanganate powder and an inorganic binder is dispersed,
After the honeycomb structure 12 having the first inorganic material layer formed thereon is immersed for several minutes, the honeycomb structure 12 is dried by a heat treatment at about 300 ° C. for about one hour to form the second inorganic material layer 26. Thus, the honeycomb structure 12 in which the second inorganic material layer 26 is coated on the first inorganic material layer 25 can be obtained.
The inorganic powder used for forming the first inorganic material layer 25 and the second inorganic material layer 26 includes an inorganic fixing aid,
For example, at least one of sodium silicate, silica, and alumina may be mixed. As silica, for example, silica sol is used. For example, alumina sol is used as alumina. The role of the inorganic fixing auxiliary agent is to function as an auxiliary agent for firmly fixing the powder of the frypontite mineral or the inorganic binder forming the first inorganic material layer 25 to the pores of the honeycomb structure 12 or the like. And an auxiliary agent for firmly fixing the manganese oxide powder and / or the permanganate powder or the inorganic binder forming the second inorganic material layer 26 to the first inorganic material layer 25. Function as

As shown in FIG. 8, the filter 1 manufactured as described above has the powder of frypontite mineral adhered to the surface of the honeycomb structure 12 in which the corrugated sheet 10 and the thin sheet 11 are laminated using an inorganic binder. To form a first inorganic material layer 25, and further fix a manganese oxide powder and / or a permanganate powder on the surface thereof using an inorganic binder to form a second inorganic material layer 26. Has become. In addition, as an inorganic binder used when forming the first inorganic material layer 25 and the second inorganic material layer 26,
If inorganic powders of the group (I) in Table 1 are used,
As described above, since these inorganic binders have a large physical adsorption capacity, gaseous organic impurities that cannot be adsorbed by the powder of flypontite mineral or manganese oxide and / or permanganate are physically contained in the pores of the binder. Can be adsorbed. Further, the inorganic binder of (I) in Table 1 can be replaced with an inorganic fixing aid in a sol state of silica sol or alumina sol. The reason is that silica sol and alumina sol are suspensions containing monodispersed nanometers to tens of nanometers of primary particles, but when they are fixed to the surface of the support and dried, the three-dimensional aggregates in which the primary particles are aggregated To silica gel or alumina gel, which has the ability to adsorb gaseous organic impurities. Accordingly, the inorganic fixing aids of silica sol and alumina sol alone are exactly the same as silica gel and alumina gel, which are inorganic binders for adsorbing gaseous organic impurities of the first inorganic material layer 25 and the second inorganic material layer 26. Available to

FIG. 9 is a partially enlarged cross-sectional view showing the first inorganic material layer 25 and the second inorganic material layer 26 in the filter 1 thus manufactured. This filter 1
The second inorganic material layer 26 covers the drawback that the flypontite mineral contained in the first inorganic material layer 25 has a layered structure, so that the powder of the flypontite mineral is liable to peel off and generate dust. There is an advantage that it can be eliminated by (coating). In addition, even when the gaseous organic impurities are desorbed from the support itself, either the first inorganic material layer 25 or the second inorganic material layer 26 is made of an inorganic binder (for example, a table) that adsorbs the gaseous organic impurities. If (1)) is included, it becomes possible to adsorb and remove gaseous organic impurities desorbed from the support.

Next, another method of manufacturing the filter 1 will be described. Until the honeycomb structure 12 is manufactured, the manufacturing method is the same as the above-described manufacturing method, and a description thereof will be omitted. In this manufacturing method, the second structure in which the surface of the honeycomb structure 12 is coated with a manganese oxide powder and / or a permanganate powder around a first pellet obtained by granulating a powder of frypontite mineral. Is attached with an inorganic adhesive. When granulating frypontite mineral powder, mixing the frypontite mineral powder with an inorganic binder with a suitable amount of water and an inorganic fixing aid mixed shows clay-like viscosity and plasticity. And granulation becomes possible. In this case, for example, city water is mixed with both the powder of the frypontite mineral and the powder of the inorganic substance to form a clay, and 0.3 to 0.8 mm
Granulate into pellets of the order with a granulator. Around the first pellets thus granulated, manganese oxide powder and / or permanganate powder are further coated with inorganic powder as a binder to form second pellets. The second pellets can be fixed to the surface of the honeycomb structure 12 by blowing the second pellets on a support to which an inorganic and nonflammable adhesive has been attached in advance using high-speed air. . The types of the inorganic binder and the inorganic fixing aid are the same as those in the above-described production method. The filter 1 thus manufactured can also adsorb and remove gaseous acidic impurities, gaseous basic impurities, and gaseous organic impurities as in the case described above with reference to FIG. Due to the presence of sulfur oxides, sulfur oxides such as sulfurous acid gas can also be removed by the frypontite mineral.

Even if the order of fixing the first inorganic material layer and the second inorganic material layer is reversed, a similar sulfurous acid gas removing effect can be obtained. In other words, when the order of the fixation in FIG. 9 is reversed, the gas to be treated starts from the surface of the inorganic material layer 26 (the surface in contact with the gas to be treated) and the fine particles of frypontite mineral in the inorganic material layer 26 and the inorganic gas. It penetrates the inside of the inorganic material layer 25 so as to pass through the air hole formed between the fine particles of the binder. Due to the presence of manganese oxide and / or permanganate in the inorganic material layer 25, sulfur oxides such as sulfurous acid gas change to sulfuric acid. This sulfuric acid is leached out of the inorganic material layer 26 of the frying-pontite mineral and removed. Other gaseous acidic impurities and gaseous basic impurities are adsorbed and removed at solid basic points and solid acidic points existing on the surface of the crystal layer of frypontite mineral in the inorganic material layer 26, respectively. In the case of FIG. 9, the manganese oxide and / or permanganate in the inorganic material layer 26 converts sulfur oxides such as sulfurous acid gas into sulfuric acid, and the sulfuric acid leaches into the inorganic material layer 25 on the support side and flies. Removed by Pontite minerals. Other gaseous acidic impurities and gaseous basic impurities are adsorbed and removed by the frypontite mineral in the inorganic material layer 25.

FIG. 10 is an explanatory diagram schematically showing the configuration of an advanced cleaning apparatus 100 according to an embodiment of the present invention.
The advanced cleaning device 100 is, for example, a clean room or a clean bench. Advanced cleaning equipment 1
Reference numeral 00 denotes a processing space 102 for manufacturing, for example, an LSI or an LCD, a ceiling (supply plenum) 103 and a lower floor (return plenum) 104 located above and below the processing space 102, and a side of the processing space 102. Is formed from the urethane passage 105 located on the side.

The ceiling unit 103 has a fan unit 110
111 for removing gaseous impurities having air permeability
And a clean fan unit 113 having a filter 112 for removing particles. In the processing space 102, for example, a semiconductor manufacturing apparatus 114 serving as a heat generation source is installed. The lower floor 104 is partitioned by a grating 115 having a large number of holes. The lower floor 1
In 04, a dry cooler (a cooler configured to prevent dew condensation) 116 for processing the heat load of the semiconductor manufacturing apparatus 114 is installed. Dry cooler 116
Means an air cooler that cools the air under conditions that do not cause condensation on the heat exchange surface. A temperature sensor 117 is provided in the urethane passage 105, and the cold water flow control valve 118 of the dry cooler 116 is controlled so that the temperature detected by the temperature sensor 117 becomes a predetermined set value.

When the fan unit 110 of the clean fan unit 113 is operated, the air inside the advanced cleaning device 100 flows from the ceiling 103 to the processing space 102 to the lower floor 104 while the airflow velocity is appropriately adjusted.
It is configured to flow and circulate from the urethane passage 105 to the ceiling 103 in this order. Further, during this circulation, it is cooled by the dry cooler 116 and the clean fan unit 11 is cooled.
The gaseous impurities and particulate impurities in the air are removed by the filter 111 for removing gaseous impurities and the filter 112 for removing particles in 3 so that clean air at an appropriate temperature is supplied into the processing space 102. Has become.

The filter 111 for removing gaseous impurities is
A filter 1 according to the present invention as described above, which comprises a powder of frypontite mineral, a powder of permanganate and / or a powder of permanganate, and is supplied in gaseous acidic / basic form from circulating air. It also removes impurities and, in some cases, gaseous organic impurities. The air purification filter 111
Is made of only a nonflammable material and is made of only a material that does not generate gaseous organic impurities by performing a baking process.

The particle removing filter 112 is disposed downstream of the air purification filter 111.
2 has a function capable of removing particulate impurities. The particle removal filter 112 is made of aluminum or ceramics for the outer frame and other components, and is made of only a material that does not generate gaseous organic impurities.

The lower part 104 of the advanced cleaning device 100
Inside, the intake outside air is appropriately supplied through an air flow path 120. The air flow path 120 is also provided with an air purification filter 121 according to the present invention for removing gaseous impurities from the taken-in outside air. A unit type air conditioner 122 for performing humidity control is provided. Further, a humidity sensor 127 is disposed in the air flow path 120, and a water supply pressure adjusting valve of a humidity control unit of the unit type air conditioner 122 so that the humidity detected by the humidity sensor 127 becomes a predetermined set value. 129 is controlled. On the other hand, in the processing space 102, a humidity sensor 128 is installed.
At 28, the humidity of the atmosphere in the processing space 102 is detected.

The intake outside air supplied from the air flow path 120 to the lower floor 104 of the advanced cleaning apparatus 100 is introduced into the processing space 102 via the retentate passage 105 and the ceiling 103. Then, an amount of air corresponding to the intake outside air is exhausted from the exhaust port 125 to the outside of the room through the exhaust gallery 126.

The air purification filter 111 according to the present invention
When the air purification filter 111 is mounted on the ceiling surface as shown in FIG. 11 because the constituent materials do not contain combustible materials, a conventional chemical filter based on activated carbon or ion exchange fiber, which is a combustible material, is mounted on the ceiling surface. Compared to the case,
Disaster prevention safety is greatly improved. In the advanced cleaning apparatus 100 shown in FIG. 10, if the air purification filter 121 for treating the intake outside air has the same configuration as the air purification filter 111 for treating the circulating air, the activated carbon or the ion-exchange fiber which is a combustible material can be used. Compared to the case where the conventional chemical filter as the base was attached to the outside air intake,
Safety in disaster prevention is further enhanced.

Medium-performance filter for removing ordinary particles, HE
The PA filter or ULPA filter uses a filter material binder containing volatile organic material as the fiber filter material, or uses a sealing material containing volatile organic material to bond the fiber filter material and the filter frame material. There is degassing from the agent. Therefore, the filter 112 for removing particles constituting the present invention uses a filter medium that does not use a filter medium binder containing a volatile organic substance, or performs baking even if a filter medium binder containing a volatile organic substance is used. Use a filter medium from which volatile organic substances have been removed, and select a type that does not generate degassing for the sealing material that is a means for fixing the filter medium to the frame. It is desirable to fix it to the frame.

Next, FIG. 11 shows an advanced cleaning apparatus 100 'according to another embodiment of the present invention. The advanced cleaning apparatus 100 'shown in FIG. 11 is a high-purity cleaning apparatus for cleaning the air-purifying filter 111 of a honeycomb structure containing the powder of the frypontite mineral according to the present invention and the powder of manganese oxide and / or permanganate. Rather than being mounted on the entire surface of the ceiling 103 of the 100 ', it is thinned out in places. In the present example, the air purification filter 11 is compared with FIG.
The number of installations of 1 was halved. Other points are described earlier in FIG.
Has the same configuration as that of the advanced cleaning device 100 described in (1). Therefore, in the advanced cleaning device 100 ′ shown in FIG. 11, the same components as those in the advanced cleaning device 100 described above with reference to FIG.

The chemical pollutants to be removed by the air purification filter of the present invention are acidic substances, basic substances, dopants, and organic substances. To explain a typical failure example, a failure common to all acidic gases is corrosion of metal wiring, but a failure specific to sulfur oxide SOx reacts with ammonia gas in the air, as described above. It adversely affects the production of precision parts. Hydrofluoric acid (HF) promotes the volatilization of boron (B) from glass fibers as a filter material for removing particles, and the basic gas hinders the resolution of the resist.
Boron (B) and phosphorus (P) cause operation failure of the semiconductor device. When a gaseous organic substance adheres to the substrate surface, a defective insulating oxide film, poor adhesion of a resist film and a high surface resistance value tend to cause electrostatic adsorption of fine particles. Further, gaseous organic substances cause clouding of lenses and mirrors of the exposure apparatus. Sources of these gaseous impurities include a source existing inside the advanced cleaning device such as a cleaning device, a worker, and a member of a clean room, and contaminants derived from outside air entering the advanced cleaning device from the outside. Therefore, the role of the air purification filter 111 is to mainly remove gaseous contaminants generated inside the advanced cleaning device from the circulating air and reduce the concentration of these gaseous contaminants inside the advanced cleaning device. For example, SOx generated from sulfuric acid, which is a chemical used in a cleaning process in an advanced cleaning device, is removed. On the other hand, the role of the air purification filter 121 disposed in the air passage 120 is to remove contaminants derived from the outside air entering the advanced cleaning device from the outside and reduce the concentration of these gaseous contaminants inside the advanced cleaning device. That is. For example,
Examples include SOx derived from air pollution and volcanic activity contained in the outside air. When the advanced cleaning apparatus equipped with the air purification filters 111 and 121 is operated, the concentration of the chemical contaminants in the advanced cleaning apparatus is highest in the initial stage of operation, and these chemical contaminants are removed from the circulating air one by one as the operation time elapses. As a result, the concentration decreases, and finally stabilizes at a concentration equilibrium with the amount generated inside the advanced cleaning device. The amount of chemical contaminants removed during a single circulation of air is determined by the advanced cleaning device 100 of FIG.
Comparing the one advanced cleaning device 100 ', there is a 2: 1 relationship. In other words, in the case of the thinned-out high-purity cleaning apparatus 100 'in FIG. 11, the time required to reach the concentration in equilibrium with the amount generated inside the high-purity cleaning apparatus from the highest concentration in the initial stage of operation is the high-purity cleaning in FIG. It is considerably longer than in the case of the device 100. In addition, the ultimately reached equilibrium concentration is slightly higher when thinned out than when mounted on the entire ceiling. In other words, although thinning takes a long time to reduce the concentration, and the equilibrium concentration after the reduction is slightly higher than the case where the thinning is not thinned, the initial cost of the air purification filter 111 and the running cost associated with the periodic replacement are reduced. Due to economic demands to do so, the number of installed air purification filters 111 is often thinned out as in the example shown in FIG.

As described above, an example of the preferred embodiment of the present invention has been described with respect to an advanced cleaning apparatus (so-called clean room) for the whole semiconductor or LCD manufacturing process. However, the present invention is not limited to this embodiment. Mini-environment high-level cleaning equipment of various scales such as local high-level cleaning equipment, clean benches, clean chambers, and various stockers for storing clean products; Various forms are conceivable depending on the processing environment such as the ratio of the amount of air and the presence or absence of gaseous impurities from inside the advanced cleaning device.

For example, using a 300 mm diameter silicon wafer, a 256 Mbit DRAM or a 1 Gbit DRAM
Semiconductor production is about to start around 1999.
In such a semiconductor manufacturing apparatus, an inert gas such as nitrogen or argon is supplied from an inert gas supply device until the reaction process is started after a wafer is introduced into the chamber in the apparatus and the wafer is introduced into the chamber. To fill. This inert gas has an extremely high purity specification, and the inert gas itself does not cause surface contamination of the wafer. However, in order to turn on and off the supply of the inert gas, a valve is provided between the inert gas supply device and the chamber, and various chemical contaminants causing wafer surface contamination are generated from the constituent material of the valve. . By providing the air purifying filter according to the present invention in the gas flow path between the valve and the chamber, the air purifying filter removes various chemical contaminants generated from the valve without generating gaseous contaminants from itself. By doing so, it is useful for preventing surface contamination of the wafer and improving the quality.

[0087]

Next, the operation and effect of the filter according to the embodiment of the present invention described above will be described with reference to examples.

FIG. 12 shows the weight mixing ratio of the frypontite mineral and manganese dioxide, where frypontite mineral: manganese dioxide (MnO ₂ ) = 5: 1 (A1) and 5: 2 (A1).
2), 5: 4 (A3)
Filters A1, A2, and A according to the embodiment of the present invention in Table 2
For 3 is a graph showing the removal performance of sulfurous acid gas SO ₂ over time. For comparison, the SO2 removal performance of a filter B0 of a comparative example having a configuration in which only the powder of the frypontite mineral was fixed to the surface of the support with an inorganic binder is also shown. Each of the filters A1, A2 and A3 is made of a powder of frypontite mineral and a powder of manganese dioxide.
In this configuration, inorganic powder is fixed as a binder on the surface of a honeycomb-shaped support. Table 2 shows each filter A1, A
2 shows the loading rate of the frypontite mineral, the loading rate of manganese dioxide, and the loading rate of the binder in A3 and B0.
Incidentally, 900Vol the SO ₂ as the processing target air pp
b containing air, ventilation air velocity 1.2 m / s, temperature 2
The temperature was 3 ° C., the relative humidity was 45%, and the thickness of the honeycomb was 50 mm. SO ₂ concentration in normal clean room atmosphere 5v
ol · ppb, the SO ₂ in this measurement
The concentration becomes 140 times the acceleration load concentration as usual.

[0089]

[Table 2]

By mixing manganese dioxide capable of oxidizing sulfurous gas into the frypontite mineral,
_It can be seen that the removal performance of No. ₂ can be exhibited. The ability to remove acidic gases such as hydrogen chloride, hydrogen sulfide, boron compounds, and hydrogen fluoride by the frypontite mineral is not impaired by mixing manganese dioxide.

[0091] Figure 13 is a fly Pont tight mineral powder and potassium permanganate powder removal performance of sulfur dioxide SO ₂ in air purifying filter A4 of the present invention having the structure is affixed to the surface of the support by the inorganic binder Change over time,
A filter B0 of a comparative example in which only a powder of frypontite mineral was fixed to the surface of a honeycomb-shaped support with an inorganic binder, and a conventional chemical filter in which granular activated carbon impregnated with potassium carbonate was bonded to a breathable urethane mat. B1 and a conventional chemical filter B in which activated carbon fibers impregnated with potassium permanganate are formed into a honeycomb shape.
2 is a graph shown in comparison with FIG. The air to be treated was air containing 800 vol ppb of SOx, the air velocity was 0.9 m / s, the temperature was 23 ° C., and the relative humidity was 4
5% and a filter thickness of 50 mm.

The sulfur dioxide SO ₂ is supplied to the chemical filter B
Since neutralization reaction with potassium carbonate 1 and zinc (or magnesium) of filter B0 is unlikely to occur, 5 vol pp
In the case of removing SO2 of b, if only 900 hours pass with the chemical filter B1 and only 600 hours pass with the filter B0, the removal efficiency becomes 50% or less. On the other hand, since potassium permanganate of the chemical filter A4 of the present invention and the conventional chemical filter B2 oxidizes sulfurous acid gas to change to sulfuric acid, 5 vol ppb of SO ₂
7000 hours and 2600 hours, respectively.
After the passage of time, the removal efficiency was below 50%. Also,
As described in FIG. 12, the filter A according to the embodiment of the present invention is used.
For 1, A2 and A3, the removal efficiency was reduced to 50% or less after about 8000 hours to about 8000 hours. From the comparison of the filters A1, A2, A3, and A4 of the embodiment of the present invention with the chemical filter B2 and the filter B0, only the frypontite mineral is insufficient for removing the sulfite gas.
It turns out that manganese oxide and permanganate are essential.

FIG. 14 shows the performance of the filter A for removing hydrogen chloride of the filter A according to the embodiment of the present invention in which the powder of frypontite mineral and the powder of manganese oxide are fixed to the surface of a honeycomb-shaped support with an inorganic binder. Change over time,
5 is a graph showing a comparison between a chemical filter B1 in which granular activated carbon impregnated with potassium carbonate is adhered to a breathable urethane mat and a chemical filter B3 in which activated carbon fibers impregnated with potassium carbonate are formed into a honeycomb shape.
The air to be treated is hydrogen chloride acceleration load concentration of 2-3.
vol 1 air containing 0.9 ppm air flow rate 0.9
m / s, temperature 23 ° C., relative humidity 45%, and filter thickness 50 mm. The filter A according to the embodiment of the present invention is a chemical filter B having a hydrogen chloride removal rate of a comparative example.
It turns out that it is considerably better than 1 and B3.

FIG. 15 shows the removal performance of hydrogen sulfide of the filter A according to the embodiment of the present invention having the structure in which the powder of the frypontite mineral and the powder of manganese oxide are fixed to the surface of the honeycomb-shaped support with an inorganic binder. Change over time,
5 is a graph showing a comparison between a chemical filter B1 in which granular activated carbon impregnated with potassium carbonate is adhered to a breathable urethane mat and a chemical filter B3 in which activated carbon fibers impregnated with potassium carbonate are formed into a honeycomb shape.
The air to be treated has a hydrogen sulfide acceleration load concentration of 90%.
Using 0 vol ppb air, ventilation air velocity 0.9 m /
s, temperature 23 ° C, relative humidity 45%, filter thickness 5
0 mm. The filter A according to the embodiment of the present invention includes:
Chemical filter B of comparative example in hydrogen sulfide removal rate
There is no inferiority to 1 and B3.

FIG. 16 shows a filter A according to an embodiment of the present invention in which powder of frypontite mineral and powder of manganese oxide are fixed to the surface of a honeycomb-shaped support with an inorganic binder. _(H 3 B
O _3), boron trifluoride (BF ₃₎ is a graph showing changes over time in removal rate. 162p of H ₃ BO ₃ as air to be treated upstream of the filter A
For pb (boron 80000 ng / m ³ ) and BF ₃ , air containing 17 ppb (boron 8560 ng / m ³ ) was used. The running condition is ventilation air velocity 0.9
m / s and the filter thickness was 50 mm. The pressure loss was 1.5 mmAq. The filter A according to the embodiment of the present invention has a filter capacity of 80 ng / m measured in a clean room.
^When converted to a concentration of ³ , the life with a removal rate of 80% or more is
Boric acid (H ³ BO ₃ ) for over 6 years, boron trifluoride (BF)
₃ ) It can be seen that it is more than one year. For comparison, FIG. 16 shows the removal rate of gaseous boric acid (H ₃ BO ₃ ) of the filter B5 of the comparative example having a configuration in which only the manganese oxide powder was fixed to the surface of the honeycomb-shaped support with an inorganic binder.
Shown inside. Filter A for boric acid (H ₃ BO ₃ )
The removal rate of the filter B5 is considerably lower than that of
It can be seen that the powder of frypontite mineral greatly increased the removal rate of gaseous boric acid.

[0096]

According to the present invention, the following effects can be obtained. In preventing contamination of the substrate surface of semiconductors and liquid crystals handled by the advanced cleaning apparatus, both gaseous inorganic impurities and gaseous organic impurities that cause substrate surface contamination contained in the atmosphere can be adsorbed and removed. In particular, sulfur oxides harmful to the production of precision electronic components and the like can be removed. For this reason, clean air suitable for production of precision electronic components and the like can be produced. In the manufacture of semiconductors and LCDs,
By using the clean air thus created as an atmosphere of an advanced cleaning device to which the substrate surface is exposed, contamination of the substrate surface could be prevented.

Also, powders of frypontite mineral and manganese oxide are used as adsorbents for adsorbing and removing gaseous inorganic impurities, and various inorganic substances are used as adsorbents for adsorbing and removing gaseous organic impurities. By appropriately selecting and combining the powders, it is possible to provide an air purification filter containing no combustible substances in the constituent materials. The advanced cleaning device constructed using this air purification filter is superior in terms of disaster prevention compared to the advanced purification device constructed using the conventional activated carbon adsorbent and the air purification filter of ion exchange fiber. In addition, it is possible to provide an air purification filter composed only of a material that does not generate gaseous organic substances that cause substrate surface contamination. Compared to an advanced cleaning device constructed using an air purification filter made of chemicals and ion exchange fibers, inorganic and organic contamination on the substrate surface could be more completely prevented.

The main impurities to be removed by the air purification filter of the present invention are gaseous inorganic impurities such as acidic substances, basic substances, and dopants. There is also an effect on the removal of water. Conventionally, four types of dedicated chemical filters had to be prepared according to each of the impurities of acid, basic, dopant, and organic substances. However, the air purification filter of the present invention requires both acidic and basic inorganic impurities. Not only collectively, but also organic impurities can be collectively removed, so that the advantages such as a reduction in the volume of the adsorption layer, a reduction in pressure loss, and a reduction in the production cost of the adsorption layer are further enhanced. In particular, an air purification filter in which an inorganic substance such as silica having a high affinity (adsorption rate) with a gaseous boron compound is present in both the first inorganic material layer and the second inorganic material layer, is a sum of inorganic substances such as silica. It is characterized in that the amount is large, the removal efficiency of the gaseous boron compound with time is small, and the gaseous boron compound can be removed for a relatively long time.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of a frypontite mineral having a double-structured crystal in which one surface is solid basic and the other surface is solid acid.

FIG. 2 is an enlargement of an inorganic material layer showing a state in which unit layers or at most several layers of frypontite having a two-layer structure are dispersed in space one by one without overlapping each other. FIG.

FIG. 3 is a schematic exploded view of the filter according to the embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of a filter in which an inorganic material layer is formed by fixing a powder of frypontite mineral and a powder of manganese oxide and / or a powder of permanganate on the surface of a honeycomb structure using an inorganic binder. FIG.

FIG. 5 is a partial enlarged cross-sectional view of the inorganic material layer showing the inorganic material layer in which the powder of the frypontite mineral, the powder of manganese oxide, and / or the powder of permanganate are supported on the surface of the support with an inorganic binder in the present invention. FIG.

FIG. 6 is a cross-sectional view of a filter having a configuration in which pellets obtained by granulating powder of fly pontitite mineral and powder of manganese oxide and / or powder of permanganate using an inorganic binder are fixed to the surface of a honeycomb structure. It is an enlarged view.

FIG. 7 is a cross-sectional view and a vertical cross-sectional view of an air purification filter in which pellets composed of powder of frypontite mineral, manganese oxide powder, and / or permanganate powder are filled in a double cylindrical casing. is there.

FIG. 8 shows a first inorganic material layer formed by fixing a fly-pontite mineral powder on the surface of a honeycomb structure in which a corrugated sheet and a thin sheet sheet are laminated using an inorganic binder, and further forming an inorganic binder on the surface. FIG. 4 is a partially enlarged cross-sectional view of a filter having a configuration in which a second inorganic material layer is formed by fixing a manganese oxide powder and / or a permanganate powder using the method described above.

FIG. 9 is a partially enlarged view of a cross section of a composite layer including a first inorganic material layer and a second inorganic material layer in the present invention.

FIG. 10 is an explanatory diagram schematically showing a configuration of an advanced cleaning device according to an embodiment of the present invention.

FIG. 11 is an explanatory view schematically showing a configuration of an advanced cleaning apparatus according to another embodiment of the present invention.

FIG. 12 shows a filter according to an embodiment of the present invention.
It is over time graph illustrating the relationship between removal performance of the fly Pont tight minerals and mixing weight ratio of manganese dioxide and sulfur dioxide SO _2.

[13] The time course of removal performance of the sulfur dioxide SO ₂ of the filter according to an embodiment of the present invention, is a graph showing, in comparison with the chemical filter.

FIG. 14 is a graph showing the change over time in the removal performance of hydrogen chloride of the filter according to the example of the present invention, as compared with a chemical filter.

FIG. 15 is a graph showing the change over time in the removal performance of hydrogen sulfide of the filter according to the example of the present invention, as compared with a chemical filter.

FIG. 16 shows a filter according to an embodiment of the present invention.
Gaseous boric acid (H ₃ BO ₃ ) or boron trifluoride (B
F ₃₎ is a graph showing, in comparison with the chemical filter over time change of the removal rate of.

[Explanation of symbols]

 Reference Signs List 1 filter 12 support body 20 inorganic material layer 21 pellet 22 casing 25 first inorganic material layer 26 second inorganic material layer 100 advanced cleaning device

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D019 AA01 AA10 BA01 BA04 BA05 BA06 BA07 BB05 BB10 BB12 BC05 BC07 BC20 CA01 CA03 CB04 CB06 4D058 JA33 JB02 JB05 JB06 JB26 JB39 JB41 KA12 KB11 KC02 SA04 TA01 TA02 TA02 TA04

Claims (15)

[Claims] An inorganic material layer is formed by fixing a powder of frypontite mineral, a powder of manganese oxide and / or a powder of permanganate to a surface of a support using an inorganic powder as a binder. An air purification filter characterized by the following. 2. A first inorganic material layer in which frypontite mineral powder is fixed with an inorganic powder as a binder, a manganese oxide powder and / or a permanganate powder, and the inorganic powder is a binder. Characterized by laminating a second inorganic material layer that has been fixed as a layer so that one of the first inorganic material layer and the second inorganic material layer is in contact with the surface of the support. Purification filter. 3. A pellet obtained by granulating a powder of a frypontite mineral, a powder of a manganese oxide and / or a powder of a permanganate using an inorganic powder as a binder, and fixing the pellet to a surface of a support. An air purification filter characterized by the following. 4. A manganese oxide powder and / or a permanganate powder, and an inorganic powder, around a first pellet obtained by granulating a powder of frypontite mineral using the inorganic powder as a binder. A second pellet coated with a binder, or a powder of manganese oxide and / or a powder of permanganate, is wrapped around the first pellet obtained by granulating an inorganic powder as a binder. An air purification filter, wherein a second pellet coated with a powder of an inorganic substance as a binder is fixed to a surface of a support. 5. The air purification filter according to claim 1, wherein the support is a honeycomb structure. 6. A pellet obtained by granulating a powder of a frypontite mineral and a powder of a manganese oxide and / or a powder of a permanganate using a powder of an inorganic substance as a binder, or a powder of the frypontite mineral, Around the first pellets granulated by using the powder of (1) as a binder, a second pellet coated with manganese oxide powder and / or permanganate powder as an inorganic powder as a binder, or manganese oxide. Powder and / or permanganate powder is granulated around the first pellets using the inorganic powder as a binder, and frying-ponite mineral powder is coated around the first pellets using the inorganic powder as a binder. An air purification filter characterized by filling pellets in a casing. 7. The manganese oxide is one of trimanganese tetroxide (Mn ₃ O ₄ ), dimanganese trioxide (Mn ₂ O ₃ ), and manganese dioxide (MnO ₂ ). Item 7. An air purification filter according to any one of Items 1, 2, 3, 4, 5 and 6. 8. The method according to claim 1, wherein the permanganate is M ^I MnO.
₄ (M ^I : alkali metal), M ^II (MnO ₄ ) ₂ (M
The air purification filter according to any one of claims 1, 2, 3, 4, 5, 6 and 7, wherein the air purification filter is any one of ( ^II : alkaline earth metal). 9. The method according to claim 9, wherein the inorganic substance is talc, kaolin mineral,
It must be at least one of bentonite, diatomaceous earth, silica, alumina, a mixture of silica and alumina, aluminum silicate, activated alumina, porous glass, hydrous magnesium silicate clay mineral having a ribbon-like structure, activated clay, and activated bentonite. Claims 1, 2, 3,
The air purification filter according to any one of 4, 5, 6, 7 and 8. 10. The inorganic material layer, the first inorganic material layer,
The second inorganic material layer, the pellet, the first pellet and the second
4. The method according to claim 1, wherein an inorganic fixing aid is mixed into at least one of the pellets.
The air purification filter according to any one of 4, 5, 6, 7, 8 and 9. 11. The air purification filter according to claim 10, wherein the inorganic fixing aid contains at least one of sodium silicate, silica and alumina. 12. A support in which a suspension of a powder of frypontite mineral, a powder of manganese oxide and / or a powder of permanganate, and a powder of an inorganic substance as a binder is impregnated with the support, A method for producing an air purification filter, comprising drying the support and fixing an inorganic material layer on the surface of the support. 13. A support in which a suspension of a powder of frypontite mineral and a powder of an inorganic substance as a binder is impregnated with a support, and the support is dried to form a first surface on the surface of the support. A support in which an inorganic material layer is formed, and the support on which the first inorganic material layer is formed is a suspension in which manganese oxide powder and / or permanganate powder and inorganic powder as a binder are dispersed. After impregnating with the liquid, drying is performed to form a second inorganic material layer on the surface of the first inorganic material layer, or after forming the second inorganic material layer on the surface of the support, A method for manufacturing an air purification filter, comprising forming the first inorganic material layer on a surface of the second inorganic material layer. 14. An advanced cleaning apparatus having a circulation path for circulating air in a space where a clean atmosphere is required,
Claims 1, 2, 3, 4, 5, 6, 7,
The air purifying filter according to any one of 8, 9, 10 and 11, and a filter for removing particulate impurities is disposed upstream of the space and downstream of the air purifying filter. Advanced cleaning equipment. 15. The advanced cleaning apparatus according to claim 14, wherein the air purification filter and the filter for removing particulate impurities are arranged on a ceiling of the space.