WO2010106925A1

WO2010106925A1 - Catalyst with supported platinum-group metal, process for producing water in which hydrogen peroxide has been decomposed, process for producing water from which dissolved oxygen has been removed, and method of cleaning electronic part

Info

Publication number: WO2010106925A1
Application number: PCT/JP2010/053647
Authority: WO
Inventors: 洋井上; 仁高田; 一重高橋; 広菅原
Original assignee: オルガノ株式会社
Priority date: 2009-03-18
Filing date: 2010-03-05
Publication date: 2010-09-23
Also published as: TWI476048B; CN102355952A; KR20110133559A; JP2010214322A; TW201038326A; KR101668132B1; JP5430983B2; CN102355952B

Abstract

A catalyst with a supported platinum-group metal, the catalyst comprising: an organic porous anion exchanger which is a continuous macroporous structure having cellular macropores overlapping each other, the overlapping parts in a water-wet state forming openings having an average diameter of 30-300 µm, and has a total pore volume of 0.5-5 mL/g and a water-wet-state anion-exchange capacity of 0.4-1.0 mg-eq/mL, and in which anion-exchange groups are evenly distributed in the organic porous anion exchanger and, in an SEM image of a cut section of the continuous macroporous structure (dry state), the area of skeletal parts appearing in the section is 25-50% of the image region; and platinum-group metal nanoparticles having an average particle diameter of 1-100 nm and deposited on the anion exchanger in an amount of 0.004-20 wt.% in terms of dry-state content. This catalyst is a high-performance catalyst which renders the decomposition and removal of hydrogen peroxide or the removal of dissolved oxygen possible even when water is passed at a high SV exceeding 2,000 h^-1 and when the catalyst is packed in a reduced thickness.

Description

Platinum group metal supported catalyst, method for producing hydrogen peroxide decomposition treatment water, method for producing dissolved oxygen removal treatment water, and method for cleaning electronic components

The present invention relates to a platinum group metal-supported catalyst for removing oxidizing substances such as hydrogen peroxide and dissolved oxygen in ultrapure water, which are used in water for precision processing such as power plant water and semiconductor manufacturing. It is.

It is known that dissolved oxygen in the water used at power plants will cause corrosion of components such as pipes and heat exchangers. In particular, dissolved oxygen is used as much as possible in the primary and secondary systems of nuclear power plants. There is a need to reduce.

In the semiconductor manufacturing industry, silicon wafers are cleaned using ultrapure water from which impurities are highly removed. Ultrapure water generally removes part of suspended matter and organic matter contained in raw water (river water, groundwater, industrial water, etc.) in the pretreatment process, and then treats the treated water with the primary pure water system and secondary pure water. Manufactured by sequential processing in an aqueous system (subsystem) and supplied to a use point for wafer cleaning. Such ultrapure water has such a purity that it is difficult to quantify the impurities, but it does not have no impurities at all.

For example, dissolved oxygen contained in ultrapure water forms a natural oxide film on the surface of the silicon wafer. When a natural oxide film is formed on the wafer surface, it prevents growth of epitaxial Si thin films at low temperatures, hinders precise control of gate oxide film pressure and film quality, and causes increase in contact resistance of contact holes. It becomes. Therefore, it is necessary to suppress the formation of the natural oxide film on the wafer surface as much as possible.

Therefore, in the ultrapure water production apparatus, particularly in the primary pure water system, dissolved oxygen is reduced using a deaeration device. With this deaeration device, the dissolved oxygen concentration in the water to be treated (primary pure water) at the entrance of the secondary pure water system is usually reduced to 100 μg / L or less. Furthermore, it may be controlled to 10 μg / L or less.

In the above-described production of ultrapure water, organic substances are generally decomposed by an ultraviolet oxidizer installed in a secondary pure water system. Since hydrogen peroxide is by-produced in the process of ultraviolet oxidation, it is common that hydrogen peroxide remains in the treated water of the ultraviolet oxidation apparatus. This hydrogen peroxide is partially decomposed in the polisher process of the secondary pure water system to generate oxygen, and increase the dissolved oxygen concentration in the treated water.

Therefore, a method of adsorbing and removing hydrogen peroxide contained in the treated water of the ultraviolet oxidizer using a synthetic carbon-based granular adsorbent has been proposed (Japanese Patent Laid-Open No. 9-29233). According to this method, it is possible to suppress the formation of a natural oxide film on the wafer surface because hydrogen peroxide itself remaining in the treated water of the ultraviolet oxidation apparatus is removed. However, this method requires a large adsorption tower filled with a large amount of a synthetic carbon-based particulate adsorbent in order to achieve a predetermined hydrogen peroxide removal rate.

In addition, a method has been proposed in which hydrogen peroxide contained in the treated water of the ultraviolet oxidation apparatus is decomposed by a catalyst in which platinum group metal nanocolloid particles are supported on a carrier (Japanese Patent Laid-Open No. 2007-185587).

JP-A-9-29233 (Claims) JP 2007-185587 A (Claims)

However, the catalyst described in JP-A-2007-185587 can not be used only at relatively low region passing water space velocity (SV) is a 100 ~ 2000h ^-1, the SV exceeds 2000h ^-1, peroxide There was a disadvantage that the decomposition and removal of hydrogen was insufficient.

Accordingly, it is an object of the present invention to be able to decompose and remove hydrogen peroxide or remove dissolved oxygen even when water is passed through a large SV exceeding SV of 2000 h ⁻¹ , and further reduce the packed bed height of the catalyst. It is an object to provide a high-performance catalyst that can decompose hydrogen peroxide or remove dissolved oxygen.

Under such circumstances, the present inventors have conducted intensive studies, and as a result, the existence of a monolithic organic porous material (intermediate) having a relatively large pore volume obtained by the method described in JP-A-2002-306976. Below, if the vinyl monomer and the cross-linking agent are allowed to stand in a specific organic solvent, a monolithic organic porous material having a large opening diameter and a thicker skeleton than that of the intermediate organic porous material can be obtained. It was found that when an ion exchange group was introduced into a thick monolithic organic porous material, the swelling was large due to the thick bone, and therefore the opening could be further increased. A platinum group having an average particle diameter of 1 to 100 nm is added to the monolithic organic porous anion exchanger (hereinafter also referred to as “first monolithic anion exchanger”) in which an anion exchange group is introduced into the thick monolithic organic porous body. A platinum group metal-supported catalyst supporting metal nanoparticles (hereinafter also referred to as “first platinum group metal-supported catalyst”) is peroxidized even when water is passed through a large SV such that the SV exceeds 2000 h ⁻¹ . It is found that hydrogen can be decomposed and removed or dissolved oxygen can be removed, and that hydrogen peroxide can be decomposed and dissolved oxygen can be removed even if the catalyst packed bed height is reduced, and the present invention is completed. It came to.

Further, as a result of intensive studies, the present inventors have found that in the presence of a monolithic organic porous material (intermediate) having a large pore volume obtained by the method described in JP-A-2002-306976, fragrance Group vinyl monomer and cross-linking agent are allowed to stand in a specific organic solvent to form a three-dimensionally continuous aromatic vinyl polymer skeleton and three-dimensionally continuous pores between the skeleton phases. A monolith with a co-continuous structure intertwined with each other, this monolith with a co-continuous structure has a high continuity of pores, is not biased in size, and has a low pressure loss during fluid permeation, It was found that a monolithic organic porous ion exchanger having a large ion exchange capacity per volume can be obtained by introducing an ion exchange group because the skeleton of this co-continuous structure is thick. This monolithic organic porous anion exchanger (hereinafter also referred to as “second monolith anion exchanger”) in which an anion exchange group is introduced into this co-continuous monolith is combined with a platinum group metal nanoparticle having an average particle diameter of 1 to 100 nm. Similar to the first platinum group metal supported catalyst, the platinum group metal supported catalyst supporting the particles (hereinafter also referred to as “second platinum group metal supported catalyst”) has a large SV exceeding 2000 h ^−1. It is possible to decompose and remove hydrogen peroxide or remove dissolved oxygen even if water is passed through the SV, and further to decompose and remove hydrogen peroxide or dissolved oxygen even if the packed bed height of the catalyst is reduced. As a result, the present invention has been completed.

That is, the present invention (1) is a platinum group metal supported catalyst in which platinum group metal nanoparticles having an average particle diameter of 1 to 100 nm are supported on an organic porous anion exchanger.
The organic porous anion exchanger is a continuous macropore structure in which cellular macropores overlap each other, and the overlapped portion is an opening having an average diameter of 30 to 300 μm in a wet state of water, and has a total pore volume of 0.5 to 5 ml. / G, an anion exchange capacity per volume in a wet state of water of 0.4 to 1.0 mg equivalent / ml, anion exchange groups are uniformly distributed in the organic porous anion exchanger, and the continuous In the SEM image of the cut surface of the macropore structure (dried body), the skeleton area that appears in the cross section is 25 to 50% in the image region,
The supported amount of the platinum group metal is 0.004 to 20% by weight in a dry state;
The platinum group metal supported catalyst characterized by these is provided.

The present invention (2) is a platinum group metal-supported catalyst in which platinum group metal nanoparticles having an average particle diameter of 1 to 100 nm are supported on an organic porous anion exchanger.
The organic porous anion exchanger is composed of an aromatic vinyl polymer containing 0.3 to 5.0 mol% of a cross-linking structural unit among all the structural units into which an anion exchange group has been introduced. A co-continuous structure comprising a three-dimensionally continuous skeleton of ˜60 μm and three-dimensionally continuous pores having a diameter of 10 to 100 μm in a water wet state between the skeletons, and the total pore volume is 0.5 to 5 ml / g, an anion exchange capacity per volume in a water-wet state is 0.3 to 1.0 mg equivalent / ml, and an anion exchange group is uniformly distributed in the organic porous anion exchanger. Distributed,
The supported amount of the platinum group metal is 0.004 to 20% by weight in a dry state;
The platinum group metal supported catalyst characterized by these is provided.

In addition, the present invention (3) is a method in which the platinum group metal-supported catalyst according to the present invention (1) or (2) is contacted with water to be treated containing hydrogen peroxide, so The present invention provides a method for producing hydrogen peroxide-decomposed water, which comprises decomposing and removing hydrogen peroxide in treated water.

Further, the present invention (4) is an electronic device characterized by washing an electronic component or an electronic component manufacturing instrument with treated water obtained by performing the method for producing hydrogen peroxide decomposition treated water of the present invention (3). A method for cleaning parts is provided.

In the present invention (5), in the presence of the platinum group metal-supported catalyst according to either the present invention (1) or (2), water is reacted with dissolved oxygen in the water to be treated to contain water. The present invention provides a method for producing dissolved oxygen-removed treated water, characterized in that dissolved oxygen is removed from water to be treated containing the oxygen.

Further, the present invention (6) is an electronic component characterized by washing an electronic component or an electronic component manufacturing instrument with treated water obtained by performing the method for producing dissolved oxygen removal treated water of the present invention (5). The cleaning method is provided.

According to the platinum group metal-supported catalyst of the present invention, it is possible to decompose and remove hydrogen peroxide or remove dissolved oxygen even when water is passed through a large SV with SV exceeding 2000 h ^−1. Even if the layer height is reduced, hydrogen peroxide can be decomposed or dissolved oxygen can be removed.

It is a SEM image of the 1st monolith. It is the EPMA image which showed the distribution state of the chloride ion in the surface of a 1st monolith anion exchanger. It is the EPMA image which showed the distribution state of the chloride ion in the cross section (thickness) direction of a 1st monolith anion exchanger. It is a manual transfer of the skeleton part that appears as a cross section of the SEM image of FIG. It is a TEM image which showed the dispersion state of the palladium nanoparticle in a 1st platinum group metal carrying | support catalyst. It is the figure which showed typically the co-continuous structure of the 2nd monolith anion exchanger. It is a SEM image of the 2nd monolith. It is the EPMA image which showed the distribution state of the chloride ion in the surface of a 2nd monolith anion exchanger. It is the EPMA image which showed the distribution state of the chloride ion in the cross section (thickness) direction of a 2nd monolith anion exchanger. It is a TEM image which showed the dispersion state of the palladium nanoparticle in the 2nd platinum group metal carrying | support catalyst. It is a SEM image of the monolith (reference product) of Reference Example 3. It is a SEM image of the 2nd monolith intermediate. It is a typical flowchart of the 1st form example of the washing | cleaning method (I) of the electronic component of this invention. It is a typical flowchart of the 2nd form example of the washing | cleaning method (I) of the electronic component of this invention.

The organic porous anion exchanger used as the carrier of the platinum group metal supported catalyst of the present invention is a “first monolith anion exchanger” or a “second monolith anion exchanger”. In the present specification, “monolithic organic porous body” is simply “monolith”, “monolithic organic porous anion exchanger” is simply “monolith anion exchanger”, and “monolithic organic porous intermediate”. Is also simply referred to as “monolith intermediate”. Further, a platinum group metal supported catalyst in which a platinum group metal is supported on the first monolith anion exchanger is referred to as “first platinum group metal supported catalyst”, and a platinum group metal is supported on the second monolith anion exchanger. The platinum group metal supported catalyst is also referred to as “second platinum group metal supported catalyst”.

<Description of the first monolith anion exchanger>
The first monolith anion exchanger is obtained by introducing an anion exchange group into the monolith. Cellular macropores overlap each other, and the overlapping portion is in a wet state in water with an average diameter of 30 to 300 μm, preferably 30 A continuous macropore structure having an opening (mesopore) of ˜200 μm, particularly preferably 40 to 100 μm. The average diameter of the opening of the monolith anion exchanger is larger than the average diameter of the opening of the monolith because the entire monolith swells when an anion exchange group is introduced into the monolith. If the average diameter of the openings in the water-wet state is less than 30 μm, the pressure loss at the time of passing water increases, which is not preferable. If the average diameter of the openings in the water-wet state is too large, the water to be treated and the monolith The contact between the anion exchanger and the supported platinum group metal nanoparticles becomes insufficient, and as a result, the hydrogen peroxide decomposition characteristics or the dissolved oxygen removal characteristics deteriorate, which is not preferable. In the present invention, the average diameter of the opening of the monolith intermediate in the dry state, the average diameter of the opening of the monolith in the dry state, and the average diameter of the opening of the monolith anion exchanger in the dry state are values measured by a mercury intrusion method. It is. Further, the average diameter of the openings of the monolith anion exchanger in the wet state is a value calculated by multiplying the average diameter of the openings of the monolith anion exchanger in the dry state by the swelling rate. Specifically, the diameter of the monolith anion exchanger in the water wet state is x1 (mm), the monolith anion exchanger in the water wet state is dried, and the diameter of the resulting monolith anion exchanger in the dry state is y1 ( mm), and the average diameter of the opening of the monolith anion exchanger in the dry state measured by the mercury intrusion method is z1 (μm), the average diameter of the opening of the monolith anion exchanger in the water wet state ( μm) is calculated by the following formula “average diameter (μm) = z1 × (x1 / y1) of the opening of the monolith anion exchanger in a wet state of water”. In addition, the average diameter of the opening of the dry monolith before the introduction of the anion exchange group and the swelling ratio of the monolith anion exchanger in the water wet state relative to the dry monolith when the anion exchange group is introduced into the dry monolith are known. In this case, the average diameter of the opening of the monolith anion exchanger in the wet state can be calculated by multiplying the average diameter of the opening of the monolith in the dry state by the swelling ratio.

In the first monolith anion exchanger, in the SEM image of the cut surface of the continuous macropore structure, the skeleton area appearing in the cross section is 25 to 50%, preferably 25 to 45% in the image region. When the area of the skeletal part appearing in the cross section is less than 25% in the image region, the skeleton becomes a thin skeleton, the mechanical strength is lowered, and the monolith anion exchanger is greatly deformed particularly when water is passed at a high flow rate. Therefore, it is not preferable. Furthermore, the contact efficiency between the water to be treated and the monolith anion exchanger and the platinum group metal nanoparticles supported thereon is lowered, and the catalytic effect is lowered, which is not preferable. If it exceeds 50%, the skeleton becomes too thick, and the This is not preferable because the pressure loss during water increases. Note that the monolith described in JP-A-2002-306976 is actually limited to the blending ratio in order to ensure a common opening even if the blending ratio of the oil phase part to water is increased to make the skeleton portion thick. The maximum value of the skeleton part area appearing in the cross section cannot exceed 25% in the image region.

The conditions for obtaining the SEM image may be any conditions as long as the skeleton appearing in the cross section of the cut surface appears clearly. For example, the magnification is 100 to 600, and the photographic area is about 150 mm × 100 mm. The SEM observation is preferably performed on three or more images, preferably five or more images, taken at arbitrary locations on an arbitrary cut surface of the monolith excluding subjectivity and at different locations. The monolith to be cut is in a dry state for use in an electron microscope. The skeleton part of the cut surface in the SEM image will be described with reference to FIGS. FIG. 4 is a transcribed skeleton that appears as a cross section of the SEM photograph of FIG. In FIGS. 1 and 4, what is generally indeterminate in shape and shown in cross section is the “skeleton portion (reference numeral 12)” in the present invention, the circular hole shown in FIG. 1 is an opening (mesopore), and A relatively large curvature or curved surface is a macropore (reference numeral 13 in FIG. 4). The skeleton part area appearing in the cross section of FIG. 4 is 28% in the rectangular image region 11. Thus, the skeleton can be clearly determined.

In the SEM image, the method for measuring the area of the skeletal part appearing in the cross section of the cut surface is not particularly limited, and after specifying the skeletal part by performing known computer processing or the like, calculation by automatic calculation or manual calculation by a computer or the like A method is mentioned. The manual calculation includes a method in which an indefinite shape is replaced with an aggregate such as a quadrangle, a triangle, a circle, or a trapezoid, and the areas are obtained by stacking them.

The total pore volume of the first monolith anion exchanger is 0.5 to 5 ml / g, preferably 0.8 to 4 ml / g. If the total pore volume is less than 0.5 ml / g, the pressure loss during water flow will increase, which is not preferable. Further, the amount of permeated fluid per unit cross-sectional area decreases, and the processing capacity decreases. Therefore, it is not preferable. On the other hand, if the total pore volume exceeds 5 ml / g, the mechanical strength decreases, and the monolith anion exchanger is greatly deformed particularly when water is passed at a high flow rate. Furthermore, since the contact efficiency between the water to be treated, the monolith anion exchanger and the platinum group metal nanoparticles supported thereon is lowered, the catalytic effect is also lowered, which is not preferable. In the present invention, the total pore volume of the monolith (monolith intermediate, monolith, monolith anion exchanger) is a value measured by a mercury intrusion method. In addition, the total pore volume of the monolith (monolith intermediate, monolith, monolith anion exchanger) is the same both in the dry state and in the water wet state.

In addition, the pressure loss at the time of making water permeate | transmit the 1st monolith anion exchanger is the pressure loss at the time of water-flowing at the water velocity (LV) of 1 m / h to the column packed with this 1m (henceforth, " In the range of 0.001 to 0.1 MPa / m · LV, particularly 0.005 to 0.05 MPa / m · LV is preferable.

The first monolith anion exchanger has an anion exchange capacity per volume of 0.4 to 1.0 mg equivalent / ml in a water-wet state. In the conventional monolithic organic porous anion exchanger having a continuous macropore structure different from the present invention as described in JP-A-2002-306976, in order to achieve a low pressure loss that is practically required, When the opening diameter is increased, the total pore volume also increases accordingly, so the anion exchange capacity per volume decreases, and the total pore volume is decreased to increase the exchange capacity per volume. In addition, since the opening diameter is reduced, the pressure loss increases. In contrast, the first monolith anion exchanger can further increase the opening diameter and thicken the skeleton of the continuous macropore structure (thicken the skeleton wall), so that the pressure loss can be kept low. The anion exchange capacity per volume can be dramatically increased. If the anion exchange capacity per volume is less than 0.4 mg equivalent / ml, the amount of platinum group metal nanoparticles supported per volume will be unfavorable. On the other hand, if the anion exchange capacity per volume exceeds 1.0 mg equivalent / ml, the pressure loss at the time of passing water increases, which is not preferable. The anion exchange capacity per weight of the first monolith anion exchanger is not particularly limited. However, since the anion exchange groups are uniformly introduced to the surface of the porous body and the inside of the skeleton, the capacity of 3.5 to 4. 5 mg equivalent / g. Note that the ion exchange capacity of the porous body in which the ion exchange group is introduced only on the surface cannot be determined unconditionally depending on the kind of the porous body or the ion exchange group, but is at most 500 μg equivalent / g.

In the first monolith anion exchanger, the material constituting the skeleton of the continuous macropore structure is an organic polymer material having a crosslinked structure. The crosslink density of the polymer material is not particularly limited, but includes 0.3 to 10 mol%, preferably 0.3 to 5 mol% of cross-linked structural units with respect to all structural units constituting the polymer material. It is preferable. If the cross-linking structural unit is less than 0.3 mol%, the mechanical strength is insufficient, which is not preferable. On the other hand, if it exceeds 10 mol%, it may be difficult to introduce an anion exchange group. The type of the polymer material is not particularly limited, and examples thereof include aromatic vinyl polymers such as polystyrene, poly (α-methylstyrene), polyvinyl toluene, polyvinyl benzyl chloride, polyvinyl biphenyl, and polyvinyl naphthalene; polyolefins such as polyethylene and polypropylene; Poly (halogenated polyolefin) such as vinyl chloride and polytetrafluoroethylene; Nitrile-based polymer such as polyacrylonitrile; Cross-linking weight of (meth) acrylic polymer such as polymethyl methacrylate, polyglycidyl methacrylate, and polyethyl acrylate Coalescence is mentioned. The polymer may be a polymer obtained by copolymerizing a single vinyl monomer and a crosslinking agent, a polymer obtained by polymerizing a plurality of vinyl monomers and a crosslinking agent, or a blend of two or more types of polymers. It may be what was done. Among these organic polymer materials, the cross-linking weight of the aromatic vinyl polymer is easy due to the ease of forming a continuous macropore structure, the ease of introducing an anion exchange group and the high mechanical strength, and the high stability to acids or alkalis. A styrene-divinylbenzene copolymer and a vinylbenzyl chloride-divinylbenzene copolymer are particularly preferable materials.

Examples of the anion exchange group of the first monolith anion exchanger include a quaternary ammonium group such as a trimethylammonium group, a triethylammonium group, a tributylammonium group, a dimethylhydroxyethylammonium group, a dimethylhydroxypropylammonium group, and a methyldihydroxyethylammonium group. , Tertiary sulfonium group, phosphonium group and the like.

In the first monolith anion exchanger, the introduced anion exchange groups are uniformly distributed not only on the surface of the porous body but also inside the skeleton of the porous body. Here, “anion exchange groups are uniformly distributed” means that the distribution of anion exchange groups is uniformly distributed on the surface and inside the skeleton in the order of at least μm. The distribution of anion exchange groups can be confirmed relatively easily by using EPMA after ion exchange of the counter anion with chloride ion, bromide ion or the like. In addition, if the anion exchange groups are uniformly distributed not only on the surface of the monolith but also within the skeleton of the porous body, the physical and chemical properties of the surface and the interior can be made uniform, so that the swelling and shrinking The durability against is improved.

(Method for producing first monolith anion exchanger)
The first monolith anion exchanger prepares a water-in-oil emulsion by stirring a mixture of oil-soluble monomer, surfactant and water that does not contain ion-exchange groups, and then polymerizes the water-in-oil emulsion. Step I to obtain a monolithic organic porous intermediate (monolith intermediate) having a continuous macropore structure with a total pore volume of 5 to 16 ml / g, a vinyl monomer, and a cross-link having at least two vinyl groups in one molecule Agent, the vinyl monomer and the crosslinking agent dissolve, but the polymer produced by polymerization of the vinyl monomer does not dissolve the organic solvent and the polymerization initiator II step II, the mixture obtained in step II is left standing, And polymerizing in the presence of the monolith intermediate obtained in the step I to obtain a thick organic porous body having a skeleton thicker than the skeleton of the monolith intermediate II Step IV the step of introducing an anion exchange group boned organic porous body obtained in the step III, obtained by performing.

In the first method for producing a monolith anion exchanger, the step I may be performed according to the method described in JP-A-2002-306976.

In the production of the monolith intermediate of step I, the oil-soluble monomer that does not contain an ion exchange group includes, for example, an ion exchange group such as a carboxylic acid group, a sulfonic acid group, and a quaternary ammonium group, and is soluble in water. Low and lipophilic monomers may be mentioned. Preferable examples of these monomers include styrene, α-methylstyrene, vinyl toluene, vinyl benzyl chloride, divinyl benzene, ethylene, propylene, isobutene, butadiene, ethylene glycol dimethacrylate, and the like. These monomers can be used singly or in combination of two or more. However, a crosslinkable monomer such as divinylbenzene or ethylene glycol dimethacrylate is selected as at least one component of the oil-soluble monomer, and the content thereof is 0.3 to 10 mol% in the total oil-soluble monomer, preferably 0.3 to 5 mol% is preferable because the amount of anion exchange groups can be quantitatively introduced in the subsequent step.

The surfactant is not particularly limited as long as it can form a water-in-oil (W / O) emulsion when an oil-soluble monomer containing no ion exchange group and water are mixed, and sorbitan monooleate, Nonionic surfactants such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan trioleate, polyoxyethylene nonylphenyl ether, polyoxyethylene stearyl ether, polyoxyethylene sorbitan monooleate; potassium oleate Anionic surfactants such as sodium dodecylbenzene sulfonate and dioctyl sodium sulfosuccinate; cationic surfactants such as distearyl dimethyl ammonium chloride; amphoteric surfactants such as lauryl dimethyl betaine can be used. That. These surfactants can be used singly or in combination of two or more. The water-in-oil emulsion refers to an emulsion in which an oil phase is a continuous phase and water droplets are dispersed therein. The amount of the surfactant added may vary depending on the type of oil-soluble monomer and the size of the target emulsion particles (macropores), but it cannot be generally stated, but the total amount of oil-soluble monomer and surfactant Can be selected within a range of about 2 to 70%.

In Step I, a polymerization initiator may be used as necessary when forming a water-in-oil emulsion. As the polymerization initiator, a compound that generates radicals by heat and light irradiation is preferably used. The polymerization initiator may be water-soluble or oil-soluble, for example, azobisisobutyronitrile, azobisdimethylvaleronitrile, azobiscyclohexanenitrile, azobiscyclohexanecarbonitrile, benzoyl peroxide, persulfate Examples thereof include potassium, ammonium persulfate, hydrogen peroxide-ferrous chloride, sodium persulfate-sodium acid sulfite, and tetramethylthiuram disulfide.

The mixing method for mixing the oil-soluble monomer not containing an ion exchange group, a surfactant, water, and a polymerization initiator to form a water-in-oil emulsion is not particularly limited. Method of mixing at once, oil-soluble monomer, surfactant and oil-soluble polymerization initiator oil-soluble component and water or water-soluble polymerization initiator water-soluble component separately and uniformly dissolved, A method of mixing the components can be used. The mixing apparatus for forming the emulsion is not particularly limited, and a normal mixer, homogenizer, high-pressure homogenizer, or the like can be used, and an appropriate apparatus may be selected to obtain a desired emulsion particle size. Moreover, there is no restriction | limiting in particular about mixing conditions, The stirring rotation speed and stirring time which can obtain the target emulsion particle size can be set arbitrarily.

The monolith intermediate obtained in step I has a continuous macropore structure. When this coexists in the polymerization system, a porous structure having a thick skeleton with the structure of the monolith intermediate as a mold is formed. The monolith intermediate is an organic polymer material having a crosslinked structure. The crosslinking density of the polymer material is not particularly limited, but it contains 0.3 to 10 mol%, preferably 0.3 to 5 mol% of crosslinked structural units with respect to all the structural units constituting the polymer material. Is preferred. When the cross-linking structural unit is less than 0.3 mol%, the mechanical strength is insufficient, which is not preferable. In particular, when the total pore volume is as large as 10 to 16 ml / g, it is preferable to contain 2 mol% or more of crosslinked structural units in order to maintain a continuous macropore structure. On the other hand, if it exceeds 10 mol%, it may be difficult to introduce an anion exchange group, which is not preferable.

The type of polymer material of the monolith intermediate is not particularly limited, and examples thereof include the same materials as the monolith polymer material described above. Thereby, the same polymer can be formed in the skeleton of the monolith intermediate, and the skeleton can be thickened to obtain a monolith having a uniform skeleton structure.

The total pore volume of the monolith intermediate is 5 to 16 ml / g, preferably 6 to 16 ml / g. If the total pore volume is too small, the total pore volume of the monolith obtained after polymerizing the vinyl monomer becomes too small, and the pressure loss during fluid permeation increases, which is not preferable. On the other hand, if the total pore volume is too large, the structure of the monolith obtained after polymerizing the vinyl monomer deviates from the continuous macropore structure, which is not preferable. In order to make the total pore volume of the monolith intermediate within the above numerical range, the ratio of monomer to water may be about 1: 5 to 1:20.

In addition, in the monolith intermediate, the average diameter of the opening (mesopore) that is the overlapping portion of the macropore and the macropore is 20 to 200 μm in a dry state. If the average diameter of the openings in the dry state is less than 20 μm, the opening diameter of the monolith obtained after polymerizing the vinyl monomer is reduced, and the pressure loss during water passage is increased, which is not preferable. On the other hand, if it exceeds 200 μm, the opening diameter of the monolith obtained after polymerizing the vinyl monomer becomes too large, and the contact between the water to be treated and the monolith anion exchanger becomes insufficient. Or, the dissolved oxygen removing property is not preferable. Monolith intermediates preferably have a uniform structure with uniform macropore size and aperture diameter, but are not limited to this, and the uniform structure is dotted with nonuniform macropores larger than the size of the uniform macropore. You may do.

Step II consists of a vinyl monomer, a crosslinking agent having at least two vinyl groups in one molecule, an organic solvent and a polymerization initiator that dissolves the vinyl monomer and the crosslinking agent but does not dissolve the polymer formed by polymerization of the vinyl monomer. A step of preparing a mixture of In addition, there is no order of I process and II process, II process may be performed after I process, and I process may be performed after II process.

The vinyl monomer used in step II is not particularly limited as long as it is a lipophilic vinyl monomer containing a polymerizable vinyl group in the molecule and having high solubility in an organic solvent, but is allowed to coexist in the polymerization system. It is preferred to select a vinyl monomer that produces the same or similar polymer material as the monolith intermediate. Specific examples of these vinyl monomers include aromatic vinyl monomers such as styrene, α-methylstyrene, vinyl toluene, vinyl benzyl chloride, vinyl biphenyl and vinyl naphthalene; α-olefins such as ethylene, propylene, 1-butene and isobutene; Diene monomers such as butadiene, isoprene and chloroprene; halogenated olefins such as vinyl chloride, vinyl bromide, vinylidene chloride and tetrafluoroethylene; nitrile monomers such as acrylonitrile and methacrylonitrile; vinyl such as vinyl acetate and vinyl propionate Esters: methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-methacrylic acid 2- Hexyl, cyclohexyl methacrylate, benzyl methacrylate, and (meth) acrylic monomer of glycidyl methacrylate. These monomers can be used singly or in combination of two or more. The vinyl monomer suitably used in the present invention is an aromatic vinyl monomer such as styrene or vinyl benzyl chloride.

The amount of these vinyl monomers added is 3 to 50 times, preferably 4 to 40 times, by weight with respect to the monolith intermediate coexisting during polymerization. If the amount of vinyl monomer added is less than 3 times that of the porous material, the resulting monolith skeleton (the thickness of the monolith skeleton wall) cannot be increased, and the anion exchange capacity per volume after the introduction of anion exchange groups is reduced. Since it becomes small, it is not preferable. On the other hand, if the amount of vinyl monomer added exceeds 50 times, the opening diameter becomes small, and the pressure loss during water passage becomes large, which is not preferable.

As the crosslinking agent used in Step II, a crosslinking agent containing at least two polymerizable vinyl groups in the molecule and having high solubility in an organic solvent is preferably used. Specific examples of the crosslinking agent include divinylbenzene, divinylnaphthalene, divinylbiphenyl, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, butanediol diacrylate, and the like. These crosslinking agents can be used singly or in combination of two or more. Preferred cross-linking agents are aromatic polyvinyl compounds such as divinylbenzene, divinylnaphthalene and divinylbiphenyl because of their high mechanical strength and stability to hydrolysis. The amount of the crosslinking agent used is preferably 0.3 to 10 mol%, particularly 0.3 to 5 mol%, based on the total amount of the vinyl monomer and the crosslinking agent. When the amount of the crosslinking agent used is less than 0.3 mol%, the mechanical strength of the monolith is insufficient, which is not preferable. On the other hand, if it exceeds 10 mol%, the amount of introduced anion exchange groups may decrease, which is not preferable. In addition, it is preferable to use the said crosslinking agent usage-amount so that it may become substantially equal to the crosslinking density of the monolith intermediate body coexisted at the time of vinyl monomer / crosslinking agent polymerization. If the amounts used of both are too large, the crosslink density distribution will be biased in the produced monolith, and cracks are likely to occur during the anion exchange group introduction reaction.

The organic solvent used in Step II is an organic solvent that dissolves the vinyl monomer and the crosslinking agent but does not dissolve the polymer formed by polymerization of the vinyl monomer. In other words, it is a poor solvent for the polymer formed by polymerization of the vinyl monomer. . Since the organic solvent varies greatly depending on the type of vinyl monomer, it is difficult to list general specific examples. For example, when the vinyl monomer is styrene, the organic solvent includes methanol, ethanol, propanol, butanol, Alcohols such as hexanol, cyclohexanol, octanol, 2-ethylhexanol, decanol, dodecanol, ethylene glycol, propylene glycol, tetramethylene glycol, glycerin; diethyl ether, ethylene glycol dimethyl ether, cellosolve, methyl cellosolve, butyl cellosolve, polyethylene glycol, polypropylene Chain (poly) ethers such as glycol and polytetramethylene glycol; hexane, heptane, octane, isooctane, decane, dode Chain saturated hydrocarbons such as down, ethyl acetate, isopropyl acetate, cellosolve acetate, esters such as ethyl propionate. Moreover, even if it is a good solvent of polystyrene like a dioxane, THF, and toluene, when it is used with the said poor solvent and the usage-amount is small, it can be used as an organic solvent. These organic solvents are preferably used so that the vinyl monomer concentration is 30 to 80% by weight. If the amount of the organic solvent used deviates from the above range and the vinyl monomer concentration is less than 30% by weight, the polymerization rate is lowered, or the monolith structure after polymerization deviates from the range of the present invention. On the other hand, if the vinyl monomer concentration exceeds 80% by weight, the polymerization may run away, which is not preferable.

As the polymerization initiator, a compound that generates radicals by heat and light irradiation is preferably used. The polymerization initiator is preferably oil-soluble. Specific examples of the polymerization initiator used in the present invention include 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis ( 2-methylbutyronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile),

dimethyl

2,2′-azobisisobutyrate, 4,4′-azobis (4-cyanovaleric acid) 1,1′-azobis (cyclohexane-1-carbonitrile), benzoyl peroxide, lauroyl peroxide, potassium persulfate, ammonium persulfate, tetramethylthiuram disulfide and the like. The amount of the polymerization initiator used varies greatly depending on the type of monomer, polymerization temperature, etc., but can be used in the range of about 0.01 to 5% with respect to the total amount of vinyl monomer and crosslinking agent.

In step III, the mixture obtained in step II is allowed to stand and polymerize in the presence of the monolith intermediate obtained in step I to obtain a thick monolith having a skeleton thicker than the skeleton of the monolith intermediate. It is a process to obtain. The monolith intermediate used in the step III plays a very important role in creating the monolith having the novel structure of the present invention. As disclosed in JP-A-7-501140 and the like, when a vinyl monomer and a crosslinking agent are allowed to stand in a specific organic solvent in the absence of a monolith intermediate, a particle aggregation type monolithic organic porous material is obtained. The body is obtained. On the other hand, when a monolith intermediate having a continuous macropore structure is present in the polymerization system as in the present invention, the structure of the monolith after polymerization changes dramatically, the particle aggregation structure disappears, and the above-mentioned thick monolith is lost. Is obtained. The reason for this has not been elucidated in detail, but in the absence of a monolith intermediate, the cross-linked polymer produced by polymerization precipitates and precipitates in the form of particles, while a particle aggregate structure is formed. When a porous body (intermediate) is present in the system, the vinyl monomer and the crosslinking agent are adsorbed or distributed from the liquid phase to the skeleton of the porous body (intermediate), and polymerization proceeds in the porous body (intermediate). Thus, it is considered that a monolith having a thick bone skeleton can be obtained. Although the opening diameter is narrowed by the progress of the polymerization, since the total pore volume of the monolith intermediate is large, an appropriate opening diameter can be obtained even if the skeleton becomes thick.

The internal volume of the reaction vessel is not particularly limited as long as it is large enough to allow the monolith intermediate to exist in the reaction vessel. When the monolith intermediate is placed in the reaction vessel, there is a gap around the monolith in plan view. Or a monolith intermediate in the reaction vessel with no gap. Of these, the thick monolith after polymerization is not pressed from the inner wall of the container and enters the reaction container without any gap, and the monolith is not distorted, and the reaction raw materials are not wasted and efficient. Even when the internal volume of the reaction vessel is large and there are gaps around the monolith after polymerization, the vinyl monomer and the crosslinking agent are adsorbed and distributed on the monolith intermediate, so the gaps in the reaction vessel A particle aggregate structure is not generated in the portion.
In step III, the monolith intermediate is placed in a reaction vessel impregnated with the mixture (solution). As described above, the blending ratio of the mixture obtained in Step II and the monolith intermediate is such that the amount of vinyl monomer added is 3 to 50 times, preferably 4 to 40 times, by weight with respect to the monolith intermediate. It is suitable to mix. Thereby, it is possible to obtain a monolith having a thick skeleton while having an appropriate opening diameter. In the reaction vessel, the vinyl monomer and the crosslinking agent in the mixture are adsorbed and distributed on the skeleton of the monolith intermediate that has been allowed to stand, and polymerization proceeds in the skeleton of the monolith intermediate.

Polymerization conditions are selected according to the type of monomer and the type of initiator. For example, when 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl peroxide, potassium persulfate, etc. are used as initiators The polymerization may be carried out by heating at 30 to 100 ° C. for 1 to 48 hours in a sealed container under an inert atmosphere. By heat polymerization, the vinyl monomer adsorbed and distributed on the skeleton of the monolith intermediate and the cross-linking agent are polymerized in the skeleton to thicken the skeleton. After completion of the polymerization, the contents are taken out and extracted with a solvent such as acetone for the purpose of removing unreacted vinyl monomer and organic solvent to obtain a thick monolith.

Next, the method of introducing an anion exchange group after producing a monolith by the above method is preferable in that the porous structure of the resulting monolith anion exchanger can be strictly controlled.

There is no restriction | limiting in particular as a method of introduce | transducing an anion exchange group into the said monolith, Well-known methods, such as a polymer reaction and graft polymerization, can be used. For example, as a method of introducing a quaternary ammonium group, if the monolith is a styrene-divinylbenzene copolymer or the like, a method of introducing a chloromethyl group with chloromethyl methyl ether or the like and then reacting with a tertiary amine; A method in which chloromethylstyrene and divinylbenzene are produced by copolymerization and reacted with a tertiary amine; N, N, N-trimethylammonium is introduced into the monolith by introducing radical initiation groups and chain transfer groups uniformly into the skeleton surface and inside the skeleton. Examples include a method of graft polymerization of ethyl acrylate and N, N, N-trimethylammoniumpropylacrylamide; a method of grafting glycidyl methacrylate in the same manner and then introducing a quaternary ammonium group by functional group conversion. Among these methods, quaternary ammonium groups can be introduced by introducing a chloromethyl group into a styrene-divinylbenzene copolymer with chloromethyl methyl ether and reacting with a tertiary amine. A method of producing a monolith by copolymerization with divinylbenzene and reacting with a tertiary amine is preferable in that the ion exchange groups can be introduced uniformly and quantitatively. Examples of ion exchange groups to be introduced include quaternary ammonium groups such as trimethylammonium group, triethylammonium group, tributylammonium group, dimethylhydroxyethylammonium group, dimethylhydroxypropylammonium group, methyldihydroxyethylammonium group, and tertiary sulfonium. Group, phosphonium group and the like.

The first monolith anion exchanger swells greatly, for example, 1.4 to 1.9 times as thick as the bone monolith, since an anion exchange group is introduced into the bone monolith. That is, the degree of swelling is much greater than that obtained by introducing an ion exchange group into a conventional monolith described in JP-A No. 2002-306976. For this reason, even if the opening diameter of the thick monolith is small, the opening diameter of the monolith ion exchanger generally increases at the above magnification. In addition, the total pore volume does not change even when the opening diameter increases due to swelling. Therefore, the first monolith ion exchanger has a high mechanical strength because it has a thick bone skeleton despite the remarkably large opening diameter.

<Description of Second Monolith Anion Exchanger>
The second monolith anion exchanger has an average thickness composed of an aromatic vinyl polymer containing 0.3 to 5.0 mol% of a cross-linking structural unit among all the structural units into which an anion exchange group has been introduced. A co-continuous structure comprising a three-dimensionally continuous skeleton of 1 to 60 μm and three-dimensionally continuous pores having an average diameter of 10 to 100 μm in a wet state between the skeletons. The volume is 0.5 to 5 ml / g, the ion exchange capacity per volume under water wet condition is 0.3 to 1.0 mg equivalent / ml, and the anion exchange group is uniform in the porous ion exchanger. Distributed.

The second monolith anion exchanger has a three-dimensionally continuous skeleton having an average thickness of 1 to 60 μm, preferably 3 to 58 μm in an wet state in which an anion exchange group is introduced, and an average diameter between the skeletons. A co-continuous structure comprising three-dimensionally continuous pores of 10 to 100 μm, preferably 15 to 90 μm, particularly preferably 20 to 80 μm in a wet state. That is, as shown in the schematic diagram of FIG. 6, the co-continuous structure is a structure 10 in which a continuous skeleton phase 1 and a continuous vacancy phase 2 are intertwined and each of them is three-dimensionally continuous. The continuous vacancies 2 have higher continuity of the vacancies than the conventional open-cell monolith and particle aggregation monolith, and the size of the vacancies 2 is not biased. Therefore, an extremely uniform ion adsorption behavior can be achieved. Moreover, since the skeleton is thick, the mechanical strength is high.

The skeleton thickness and pore diameter of the second monolith anion exchanger are larger than the monolith skeleton thickness and pore diameter because the entire monolith swells when an anion exchange group is introduced into the monolith. It becomes. These continuous pores have higher continuity of the pores than the conventional open-cell type monolithic organic porous anion exchanger and particle aggregation type monolithic organic porous anion exchanger, and the size thereof is not biased. Therefore, an extremely uniform anion adsorption behavior can be achieved. If the average diameter of the three-dimensionally continuous pores is less than 10 μm in a water-wet state, it is not preferable because the pressure loss at the time of water flow increases, and if it exceeds 100 μm, the water to be treated and the organic porous anion The contact with the exchanger becomes insufficient, and as a result, decomposition of hydrogen peroxide in the water to be treated or removal of dissolved oxygen becomes insufficient, which is not preferable. In addition, when the average thickness of the skeleton is less than 1 μm in a wet state, the anion exchange capacity per volume is reduced, and the mechanical strength is reduced. This is not preferable because the anion exchanger is greatly deformed. Furthermore, the contact efficiency between the water to be treated and the monolith anion exchanger is lowered, and the catalytic effect is lowered. On the other hand, if the thickness of the skeleton exceeds 60 μm, the skeleton becomes too thick and pressure loss during water passage increases, which is not preferable.

The average diameter of the pores of the continuous structure in the water-wet state is a value calculated by multiplying the average diameter of the pores of the dry monolith anion exchanger measured by the mercury intrusion method and the swelling ratio. Specifically, the water-wet monolith anion exchanger has a diameter of x2 (mm), the water-wet monolith anion exchanger is dried, and the resulting dried monolith anion exchanger has a diameter y2 ( mm), and the average diameter of the pores when the dried monolith anion exchanger was measured by mercury porosimetry was z2 (μm), the pores of the monolith anion exchanger in the water-wet state The average diameter (μm) is calculated by the following formula: “average diameter of pores of monolith anion exchanger in water wet state (μm) = z2 × (x2 / y2)”. In addition, the average diameter of the pores of the dried monolith before introduction of the anion exchange group, and the swelling ratio of the monolith anion exchanger in the water wet state relative to the dried monolith when the anion exchange group is introduced into the dried monolith If it is known, the average diameter of the pores of the monolith anion exchanger in the water wet state can be calculated by multiplying the average diameter of the pores of the monolith in the dry state by the swelling rate. The average thickness of the skeleton of the continuous structure in the water-wet state is obtained by performing SEM observation of the monolith anion exchanger in a dry state at least three times, and measuring the thickness of the skeleton in the obtained image. It is a value calculated by multiplying the average value by the swelling rate. Specifically, the water-wet monolith anion exchanger has a diameter of x3 (mm), the water-wet monolith anion exchanger is dried, and the resulting dry monolith anion exchanger has a diameter of y3 ( SEM observation of the dried monolith anion exchanger at least three times, and the thickness of the skeleton in the obtained image was measured, and the average value was z3 (μm). The average thickness (μm) of the skeleton of the continuous structure of the monolith anion exchanger in the wet state is expressed by the following formula: “average thickness of the skeleton of the continuous structure of the monolith anion exchanger in the wet state of water (μm) = z3 × ( x3 / y3) ". In addition, the average thickness of the skeleton of the dried monolith before introduction of the anion exchange group, and the swelling ratio of the monolith anion exchanger in the water wet state relative to the dried monolith when the anion exchange group is introduced into the dried monolith If it is known, the average thickness of the skeleton of the monolith anion exchanger in the wet state can be calculated by multiplying the average thickness of the skeleton of the monolith in the dry state by the swelling rate. The skeleton has a rod-like shape and a circular cross-sectional shape, but may have a cross-section with a different diameter such as an elliptical cross-sectional shape. The thickness in this case is the average of the minor axis and the major axis.

The total pore volume of the second monolith anion exchanger is 0.5 to 5 ml / g. If the total pore volume is less than 0.5 ml / g, the pressure loss at the time of water flow is increased, which is not preferable. Further, the amount of permeated water per unit cross-sectional area is decreased, and the amount of treated water is decreased. Therefore, it is not preferable. On the other hand, if the total pore volume exceeds 5 ml / g, the anion exchange capacity per volume decreases, the amount of platinum group metal nanoparticles supported decreases, and the catalytic effect decreases. Further, the mechanical strength is lowered, and the monolith anion exchanger is greatly deformed particularly when water is passed at a high flow rate, which is not preferable. Furthermore, since the contact efficiency between the water to be treated and the monolith anion exchanger is lowered, the hydrogen peroxide decomposition effect or the dissolved oxygen removal effect is also lowered, which is not preferable. If the three-dimensional continuous pore size and total pore volume are within the above ranges, the contact with the water to be treated is extremely uniform, the contact area is large, and water can flow through under low pressure loss. Become. Note that the total pore volume of the monolith (monolith intermediate, monolith, monolith anion exchanger) is the same in both the dry state and the water wet state.

The pressure loss when water is permeated through the second monolith anion exchanger is the pressure loss when water is passed through a column filled with 1 m of a porous material at a water flow rate (LV) of 1 m / h (hereinafter referred to as “pressure loss”). , Referred to as “differential pressure coefficient”) in the range of 0.001 to 0.5 MPa / m · LV, particularly 0.005 to 0.1 MPa / m · LV.

In the second monolith anion exchanger, the material constituting the skeleton of the co-continuous structure comprises 0.3 to 5 mol%, preferably 0.5 to 3.0 mol% of the crosslinked structural unit in all the structural units. It is an aromatic vinyl polymer containing and is hydrophobic. If the cross-linking structural unit is less than 0.3 mol%, the mechanical strength is insufficient, which is not preferable. On the other hand, if it exceeds 5 mol%, the structure of the porous body tends to deviate from the bicontinuous structure. There is no restriction | limiting in particular in the kind of this aromatic vinyl polymer, For example, a polystyrene, poly ((alpha) -methylstyrene), polyvinyl toluene, polyvinyl benzyl chloride, polyvinyl biphenyl, polyvinyl naphthalene etc. are mentioned. The polymer may be a polymer obtained by copolymerizing a single vinyl monomer and a crosslinking agent, a polymer obtained by polymerizing a plurality of vinyl monomers and a crosslinking agent, or a blend of two or more types of polymers. It may be what was done. Among these organic polymer materials, a styrene-divinylbenzene copolymer is obtained due to the ease of forming a co-continuous structure, the ease of introducing an anion exchange group and the high mechanical strength, and the high stability to acids or alkalis. And vinylbenzyl chloride-divinylbenzene copolymer is preferred.

The second monolith anion exchanger has an anion exchange capacity of 0.3 to 1.0 mg equivalent / ml per volume in a water-wet state. In the conventional monolithic organic porous ion exchanger having a continuous macropore structure different from the present invention as described in JP-A-2002-306976, in order to achieve a low pressure loss that is practically required, When the opening diameter is increased, the total pore volume is increased accordingly, so that the ion exchange capacity per volume is decreased, and the total pore volume is decreased to increase the exchange capacity per volume. In addition, since the opening diameter is reduced, the pressure loss increases. On the other hand, the second monolith anion exchanger of the present invention has high continuity and uniformity of three-dimensionally continuous pores, so that the pressure loss does not increase so much even if the total pore volume is reduced. Therefore, the anion exchange capacity per volume can be dramatically increased while keeping the pressure loss low. If the anion exchange capacity per volume is less than 0.3 mg equivalent / ml, the amount of platinum group metal nanoparticles supported per volume will be unfavorable. On the other hand, if the anion exchange capacity per volume exceeds 1.0 mg equivalent / ml, the pressure loss at the time of passing water increases, which is not preferable. In addition, the anion exchange capacity per weight in the dry state of the second monolith anion exchanger is not particularly limited. However, since the ion exchange groups are uniformly introduced to the skeleton surface and inside the skeleton of the porous body. 5 to 4.5 mg equivalent / g. The ion exchange capacity of a porous body in which ion exchange groups are introduced only on the surface of the skeleton cannot be determined unconditionally depending on the kind of the porous body or ion exchange groups, but is at most 500 μg equivalent / g.

The anion exchange group in the second monolith anion exchanger is the same as the anion exchange group in the first monolith anion exchanger, and the description thereof is omitted. In the second monolith anion exchanger, the introduced anion exchange groups are uniformly distributed not only on the surface of the porous body but also inside the skeleton of the porous body. The definition of the uniform distribution is the same as the definition of the uniform distribution of the first monolith anion exchanger.

(Method for producing second monolith anion exchanger)
The second monolith anion exchanger prepares a water-in-oil emulsion by stirring a mixture of oil-soluble monomer, surfactant and water that does not contain ion-exchange groups, and then polymerizes the water-in-oil emulsion. Step I to obtain a monolithic organic porous intermediate having a continuous macropore structure having a total pore volume of more than 16 ml / g and 30 ml / g or less, an aromatic vinyl monomer, and at least two or more vinyl groups in one molecule From 0.3 to 5 mol% of the cross-linking agent, aromatic vinyl monomer and cross-linking agent dissolved in the total oil-soluble monomer, but from the organic solvent and polymerization initiator that does not dissolve the polymer formed by polymerization of the aromatic vinyl monomer Polymerization is carried out in the presence of the monolithic organic porous intermediate obtained in Step I, while allowing the mixture obtained in Step II and Step II to stand. Obtained by performing a co-continuous structure III to obtain a, IV introducing an anion exchange group to the resulting co-continuous structure in the step III.

The step I for obtaining the monolith intermediate in the second monolith anion exchanger may be performed according to the method described in JP-A-2002-306976.

That is, in the step I, as the oil-soluble monomer not containing an ion exchange group, for example, it does not contain an ion exchange group such as a carboxylic acid group, a sulfonic acid group, and a quaternary ammonium group, has low solubility in water, and is lipophilic. These monomers are mentioned. Specific examples of these monomers include aromatic vinyl monomers such as styrene, α-methylstyrene, vinyl toluene, vinyl benzyl chloride, vinyl biphenyl and vinyl naphthalene; α-olefins such as ethylene, propylene, 1-butene and isobutene; butadiene Diene monomers such as vinyl chloride, vinyl bromide, vinylidene chloride and tetrafluoroethylene; nitrile monomers such as acrylonitrile and methacrylonitrile; vinyl esters such as vinyl acetate and vinyl propionate Methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethyl methacrylate Sill, cyclohexyl methacrylate, benzyl methacrylate, and (meth) acrylic monomer of glycidyl methacrylate. Among these monomers, preferred are aromatic vinyl monomers such as styrene, α-methylstyrene, vinyl toluene, vinyl benzyl chloride, divinyl benzene and the like. These monomers can be used singly or in combination of two or more. However, a crosslinkable monomer such as divinylbenzene or ethylene glycol dimethacrylate is selected as at least one component of the oil-soluble monomer, and its content is 0.3 to 5 mol%, preferably 0.3 to 3 mol% is preferable because it is advantageous for forming a co-continuous structure.

The surfactant is the same as the surfactant used in Step I of the first monolith anion exchanger, and the description thereof is omitted.

In Step I, a polymerization initiator may be used as necessary when forming a water-in-oil emulsion. As the polymerization initiator, a compound that generates radicals by heat and light irradiation is preferably used. The polymerization initiator may be water-soluble or oil-soluble. For example, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2 , 2′-azobis (2-methylbutyronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile),

dimethyl

2,2′-azobisisobutyrate, 4,4′-azobis ( 4-cyanovaleric acid), 1,1'-azobis (cyclohexane-1-carbonitrile), benzoyl peroxide, lauroyl peroxide, potassium persulfate, ammonium persulfate, tetramethylthiuram disulfide, hydrogen peroxide-ferrous chloride Sodium persulfate-sodium acid sulfite and the like.

As a mixing method when an oil-soluble monomer not containing an ion exchange group, a surfactant, water, and a polymerization initiator are mixed to form a water-in-oil emulsion, the first monolith anion exchanger in Step I is used. This is the same as the mixing method, and the description thereof is omitted.

In the second method for producing a monolith anion exchanger, the monolith intermediate obtained in step I is an organic polymer material having a crosslinked structure, preferably an aromatic vinyl polymer. The crosslinking density of the polymer material is not particularly limited, but it contains 0.3 to 5 mol%, preferably 0.3 to 3 mol% of crosslinked structural units with respect to all the structural units constituting the polymer material. Is preferred. When the cross-linking structural unit is less than 0.3 mol%, the mechanical strength is insufficient, which is not preferable. On the other hand, if it exceeds 5 mol%, the structure of the monolith tends to deviate from the co-continuous structure, which is not preferable. In particular, when the total pore volume is as small as 16 to 20 ml / g in the present invention, in order to form a co-continuous structure, the cross-linking structural unit is preferably less than 3 mol%.

The kind of the polymer material of the monolith intermediate is the same as the kind of the polymer material of the monolith intermediate of the first monolith anion exchanger, and the description thereof is omitted.

The total pore volume of the monolith intermediate is more than 16 ml / g and not more than 30 ml / g, preferably more than 16 ml / g and not more than 25 ml / g. In other words, this monolith intermediate is basically a continuous macropore structure, but the opening (mesopore) that is the overlap between macropores and macropores is remarkably large. It has a structure that is as close as possible to the original rod-like skeleton. When this coexists in the polymerization system, a porous body having a co-continuous structure is formed using the structure of the monolith intermediate as a mold. If the total pore volume is too small, the structure of the monolith obtained after polymerizing the vinyl monomer is not preferable because it changes from a co-continuous structure to a continuous macropore structure. On the other hand, if the total pore volume is too large, This is not preferable because the mechanical strength of the monolith obtained after polymerizing the vinyl monomer is lowered and the anion exchange capacity per volume is lowered. In order for the total pore volume of the monolith intermediate to be in a specific range of the second monolith anion exchanger, the ratio of monomer to water may be approximately 1:20 to 1:40.

In addition, in the monolith intermediate, the average diameter of openings (mesopores), which are the overlapping portions of macropores and macropores, is 5 to 100 μm in a dry state. When the average diameter of the openings is less than 5 μm in the dry state, the opening diameter of the monolith obtained after polymerizing the vinyl monomer is reduced, and the pressure loss during fluid permeation is increased, which is not preferable. On the other hand, if it exceeds 100 μm, the opening diameter of the monolith obtained after polymerizing the vinyl monomer becomes too large, resulting in insufficient contact between the water to be treated and the monolith anion exchanger, resulting in hydrogen peroxide decomposition characteristics. Or, the dissolved oxygen removing property is not preferable. Monolith intermediates preferably have a uniform structure with uniform macropore size and aperture diameter, but are not limited to this, and the uniform structure is dotted with nonuniform macropores larger than the size of the uniform macropore. You may do.

In the second method for producing a monolith anion exchanger, the step II includes 0.3 to 5 mol% of a crosslinking agent in the aromatic vinyl monomer and the total oil-soluble monomer having at least two or more vinyl groups in one molecule. This is a step of preparing a mixture comprising an organic solvent and a polymerization initiator that dissolves the aromatic vinyl monomer and the crosslinking agent but does not dissolve the polymer formed by polymerization of the aromatic vinyl monomer. In addition, there is no order of I process and II process, II process may be performed after I process, and I process may be performed after II process.

In the second method for producing a monolith anion exchanger, the aromatic vinyl monomer used in step II includes a lipophilic aromatic vinyl monomer that contains a polymerizable vinyl group in the molecule and has high solubility in an organic solvent. If it is, there is no particular limitation, but it is preferable to select a vinyl monomer that produces the same or similar polymer material as the monolith intermediate coexisting in the polymerization system. Specific examples of these vinyl monomers include styrene, α-methylstyrene, vinyl toluene, vinyl benzyl chloride, vinyl biphenyl, vinyl naphthalene and the like. These monomers can be used singly or in combination of two or more. Aromatic vinyl monomers preferably used in the present invention are styrene, vinyl benzyl chloride and the like.

The amount of these aromatic vinyl monomers added is 5 to 50 times, preferably 5 to 40 times, by weight with respect to the monolith intermediate coexisting during polymerization. If the amount of the aromatic vinyl monomer added is less than 5 times that of the monolith intermediate, the rod-like skeleton cannot be made thick, and the anion exchange capacity per volume after the introduction of the anion exchange group becomes small. On the other hand, if the amount of the aromatic vinyl monomer added exceeds 50 times, the diameter of the continuous pores becomes small and the pressure loss during water passage becomes large, which is not preferable.

As the crosslinking agent used in Step II, a crosslinking agent containing at least two polymerizable vinyl groups in the molecule and having high solubility in an organic solvent is preferably used. Specific examples of the crosslinking agent include divinylbenzene, divinylnaphthalene, divinylbiphenyl, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, butanediol diacrylate, and the like. These crosslinking agents can be used singly or in combination of two or more. Preferred cross-linking agents are aromatic polyvinyl compounds such as divinylbenzene, divinylnaphthalene and divinylbiphenyl because of their high mechanical strength and stability to hydrolysis. The amount of the crosslinking agent used is 0.3 to 5 mol%, particularly 0.3 to 3 mol%, based on the total amount of vinyl monomer and crosslinking agent (total oil-soluble monomer). When the amount of the crosslinking agent used is less than 0.3 mol%, it is not preferable because the mechanical strength of the monolith is insufficient. On the other hand, when the amount is too large, it may be difficult to quantitatively introduce the anion exchange group. . In addition, it is preferable to use the said crosslinking agent usage-amount so that it may become substantially equal to the crosslinking density of the monolith intermediate body coexisted at the time of vinyl monomer / crosslinking agent polymerization. If the amounts used of both are too large, the crosslink density distribution will be biased in the produced monolith, and cracks are likely to occur during the anion exchange group introduction reaction.

The organic solvent used in step II is an organic solvent that dissolves the aromatic vinyl monomer and the crosslinking agent but does not dissolve the polymer formed by polymerization of the aromatic vinyl monomer, in other words, is formed by polymerization of the aromatic vinyl monomer. It is a poor solvent for polymers. Since the organic solvent varies greatly depending on the type of the aromatic vinyl monomer, it is difficult to list general specific examples. For example, when the aromatic vinyl monomer is styrene, the organic solvent includes methanol, ethanol, Alcohols such as propanol, butanol, hexanol, cyclohexanol, octanol, 2-ethylhexanol, decanol, dodecanol, propylene glycol, tetramethylene glycol; chain structures such as diethyl ether, butyl cellosolve, polyethylene glycol, polypropylene glycol, polytetramethylene glycol (Poly) ethers; chain saturated hydrocarbons such as hexane, heptane, octane, isooctane, decane, dodecane; ethyl acetate, isopropyl acetate, cellosolve acetate, propionic acid Examples include esters such as ethyl. Moreover, even if it is a good solvent of polystyrene like a dioxane, THF, and toluene, when it is used with the said poor solvent and the usage-amount is small, it can be used as an organic solvent. These organic solvents are preferably used so that the concentration of the aromatic vinyl monomer is 30 to 80% by weight. If the amount of the organic solvent used deviates from the above range and the aromatic vinyl monomer concentration becomes less than 30% by weight, the polymerization rate is lowered, or the monolith structure after polymerization deviates from the scope of the present invention, which is not preferable. On the other hand, if the concentration of the aromatic vinyl monomer exceeds 80% by weight, the polymerization may run away, which is not preferable.

The polymerization initiator is the same as the polymerization initiator used in Step II of the first monolith anion exchanger, and the description thereof is omitted.

In the second method for producing a monolith anion exchanger, in the step III, the mixture obtained in the step II is allowed to stand and the polymerization is carried out in the presence of the monolith intermediate obtained in the step I. This is a process of obtaining a monolith having a co-continuous structure by changing the continuous macropore structure of the body into a co-continuous structure. The monolith intermediate used in the step III plays a very important role in creating the monolith having the novel structure of the present invention. As disclosed in JP-A-7-501140 and the like, when a vinyl monomer and a crosslinking agent are allowed to stand in a specific organic solvent in the absence of a monolith intermediate, a particle aggregation type monolithic organic porous material is obtained. The body is obtained. On the other hand, when a monolith intermediate having a specific continuous macropore structure is present in the polymerization system as in the second monolith of the present invention, the structure of the monolith after the polymerization changes dramatically and the particle aggregation structure disappears. Thus, a monolith having the above-described bicontinuous structure can be obtained. The reason for this has not been elucidated in detail, but in the absence of a monolith intermediate, the cross-linked polymer produced by polymerization precipitates and precipitates in the form of particles, while a particle aggregate structure is formed. When a porous body (intermediate) having a large total pore volume is present in the system, the vinyl monomer and the crosslinking agent are adsorbed or distributed from the liquid phase to the skeleton of the porous body, and polymerization proceeds in the porous body. It is considered that the skeleton constituting the monolith structure is changed from a two-dimensional wall surface to a one-dimensional rod-like skeleton to form a monolithic organic porous body having a co-continuous structure.

The internal volume of the reaction vessel is the same as the description of the internal volume of the reaction vessel of the first monolith anion exchanger, and the description thereof is omitted.

In step III, the monolith intermediate is placed in a reaction vessel impregnated with a mixture (solution). As described above, the blending ratio of the mixture obtained in Step II and the monolith intermediate is 5 to 50 times, preferably 5 to 40 times, by weight of the aromatic vinyl monomer added to the monolith intermediate. It is preferable to blend them as described above. Thereby, it is possible to obtain a monolith having a co-continuous structure in which pores of an appropriate size are three-dimensionally continuous and a thick skeleton is three-dimensionally continuous. In the reaction vessel, the aromatic vinyl monomer and the cross-linking agent in the mixture are adsorbed and distributed on the skeleton of the monolith intermediate that is allowed to stand, and polymerization proceeds in the skeleton of the monolith intermediate.

The basic structure of a monolith having a co-continuous structure is a three-dimensional structure having a three-dimensionally continuous average thickness of 0.8 to 40 μm in a dry state and a mean diameter of 8 to 80 μm in a dry state between the skeletons. In this structure, continuous holes are arranged. The average diameter of the three-dimensionally continuous pores in the dry state can be obtained as a maximum value of the pore distribution curve by measuring the pore distribution curve by a mercury intrusion method. The thickness of the skeleton of the dried monolith may be calculated by performing SEM observation at least three times and measuring the average thickness of the skeleton in the obtained image. A monolith having a co-continuous structure has a total pore volume of 0.5 to 5 ml / g.

Polymerization conditions are the same as the description of the polymerization conditions in the III step of the first monolith anion exchanger, and the description thereof is omitted.

In the IV step, the method for introducing an anion exchange group into a monolith having a co-continuous structure is the same as the method for introducing an anion exchange group into the monolith in the first monolith anion exchanger, and the description thereof is omitted.

The second monolith anion exchanger swells to be 1.4 to 1.9 times larger than the monolith, for example, because an anion exchange group is introduced into the monolith having a co-continuous structure. Further, the total pore volume does not change even if the pore diameter becomes larger due to swelling. Therefore, the second monolith anion exchanger has a high mechanical strength because it has a thick bone skeleton, although the size of three-dimensionally continuous pores is remarkably large. Further, since the skeleton is thick, the anion exchange capacity per volume in a water-wet state can be increased, and furthermore, the water to be treated can be passed for a long time at a low pressure and a large flow rate.

<First platinum group metal supported catalyst and second platinum group metal supported catalyst>
The first platinum group metal-supported catalyst of the present invention is a platinum group metal-supported catalyst in which platinum group metal nanoparticles are supported on a first monolith anion exchanger. The second platinum group metal supported catalyst of the present invention is a platinum group metal supported catalyst in which platinum group metal nanoparticles are supported on the second monolith anion exchanger.

The platinum group metal according to the present invention is ruthenium, rhodium, palladium, osmium, iridium, or platinum. These platinum group metals may be used alone or in combination of two or more metals, and more than one metal may be used as an alloy. Among these, platinum, palladium, and platinum / palladium alloys have high catalytic activity and are preferably used.

The average particle diameter of the platinum group metal nanoparticles according to the present invention is 1 to 100 nm, preferably 1 to 50 nm, and more preferably 1 to 20 nm. If the average particle size is less than 1 nm, the possibility that the nanoparticles are detached from the carrier increases, which is not preferable. On the other hand, if the average particle size exceeds 100 nm, the surface area per unit mass of the metal is reduced and the catalytic effect is reduced. Is not preferred because it cannot be obtained efficiently. When the average particle diameter of the nanoparticles is within the above range, the nanoparticles are strongly colored by surface plasmon resonance and can be confirmed by visual observation.

The amount of platinum group metal nanoparticles supported in the dried first platinum group metal supported catalyst ((platinum group metal nanoparticles / dried first platinum group metal supported catalyst) × 100) is 0.004 to 20% by weight, preferably 0.005 to 15% by weight. The amount of platinum group metal nanoparticles supported in the second platinum group metal supported catalyst in the dry state ((platinum group metal nanoparticles / second platinum group metal supported catalyst in the dry state) × 100) is 0.00. 004 to 20% by weight, preferably 0.005 to 15% by weight. If the supported amount of platinum group metal nanoparticles is less than 0.004% by weight, the effect of decomposing hydrogen peroxide or the effect of removing dissolved oxygen becomes insufficient. On the other hand, when the amount of platinum group metal nanoparticles is more than 20% by weight, metal elution into water is observed, which is not preferable.

There are no particular restrictions on the method for producing the first platinum group metal-supported catalyst and the second platinum group metal-supported catalyst, and platinum is added to the first monolith anion exchanger or the second monolith anion exchanger by a known method. The first platinum group metal-supported catalyst or the second platinum group metal-supported catalyst can be obtained by supporting the group metal nanoparticles. For example, the first monolith anion exchanger or the second monolith anion exchanger in a dry state is immersed in an aqueous hydrochloric acid solution of palladium chloride, the chloropalladate anion is adsorbed on the monolith anion exchanger by ion exchange, and then the reducing agent The palladium metal nanoparticles are brought into contact with the first monolith anion exchanger or the second monolith anion exchanger, or the column is packed with the first monolith anion exchanger or the second monolith anion exchanger. Then, a hydrochloric acid aqueous solution of palladium chloride is passed through and the chloropalladate anion is adsorbed on the first monolith anion exchanger or the second monolith anion exchanger by ion exchange, and then a reducing agent is passed through the palladium metal nanoparticle. The particles are supported on the first monolith anion exchanger or the second monolith anion exchanger Law, and the like. There are no particular restrictions on the reducing agent used, alcohols such as methanol, ethanol and isopropanol, carboxylic acids such as formic acid, oxalic acid, citric acid and ascorbic acid, ketones such as acetone and methyl ethyl ketone, aldehydes such as formaldehyde and acetaldehyde, Examples thereof include sodium borohydride and hydrazine.

In the first platinum group metal-supported catalyst, the ionic form of the first monolith anion exchanger, which is the carrier of the platinum group metal nanoparticles, is usually in the form of chloride after the platinum group metal nanoparticles are supported. It becomes salt form. In the present invention, such a salt form may be used as a catalyst for decomposing hydrogen peroxide or removing dissolved oxygen. In addition, the first platinum group metal supported catalyst is not limited to this, and the ion form of the first monolith anion exchanger may be regenerated to OH form. Of these, the ionic form of the first monolith anion exchanger is preferably OH form, since a high catalytic effect is obtained. Similarly, in the second platinum group metal-supported catalyst, the ionic form of the second monolith anion exchanger, which is the carrier of the platinum group metal nanoparticles, is usually chlorinated after the platinum group metal nanoparticles are supported. It becomes a salt form like a physical form. In the present invention, such a salt form may be used as a catalyst for decomposing hydrogen peroxide or removing dissolved oxygen. In addition, the second platinum group metal supported catalyst is not limited to this, and may be the one obtained by regenerating the ion form of the second monolith anion exchanger into the OH form. Of these, the ionic form of the second monolith anion exchanger is preferably OH form, because a high catalytic effect is obtained. The method for regenerating the monolith anion exchanger after supporting the platinum group metal nanoparticles to the OH form is not particularly limited, and a known method such as passing a sodium hydroxide aqueous solution may be used.

<Method for Producing Hydrogen Peroxide Decomposition Treatment Water>
In the method for producing hydrogen peroxide decomposition treated water according to the present invention, the first platinum group metal-supported catalyst or the second platinum group metal-supported catalyst is brought into contact with the treated water containing hydrogen peroxide, and then the peroxide is oxidized. This is a method for producing hydrogen peroxide decomposition treated water by decomposing and removing hydrogen peroxide in water to be treated containing hydrogen. Hereinafter, the first platinum group metal supported catalyst and the second platinum group metal supported catalyst are collectively referred to as the platinum group metal supported catalyst of the present invention.

The water to be treated containing hydrogen peroxide is not particularly limited as long as it contains hydrogen peroxide. For example, ultrapure water used for manufacturing electronic components such as semiconductor manufacturing and for cleaning electronic device manufacturing equipment. In the production of water, water generated by various processes therein can be mentioned, and specifically, water after performing an ultraviolet oxidation process for decomposing organic substances in the water. In addition, as the water to be treated containing hydrogen peroxide, in addition to the treatment liquid or treatment water obtained by adding hydrogen peroxide to the waste water system, and performing oxidation, reduction, sterilization and washing, these treatment liquids or The waste liquid or waste water after processing using treated water is mentioned. For example, in order to collect and reuse cleaning wastewater containing hydrogen peroxide discharged from the semiconductor manufacturing process and cleaning wastewater containing organic matter discharged from the semiconductor manufacturing process as ultrapure water, ultraviolet rays are used in the presence of hydrogen peroxide. Treated water obtained by oxidative decomposition of organic matter by irradiation, treated water obtained by decomposing organic matter using Fenton reagent, reverse osmosis membrane, waste water after sterilizing or washing ultrafiltration membrane with hydrogen peroxide, Examples thereof include treated water obtained by reducing wastewater containing hexavalent chromium with hydrogen peroxide.

The hydrogen peroxide concentration in the water to be treated containing hydrogen peroxide is not particularly limited, but is usually 0.01 to 100 mg / L. In the ultrapure water production subsystem, the hydrogen peroxide concentration is typically 10-50 μg / L. When the hydrogen peroxide concentration exceeds 100 mg / L, deterioration of the base monolith anion exchanger tends to proceed.

The method for bringing the water to be treated containing hydrogen peroxide into contact with the platinum group metal supported catalyst of the present invention is not particularly limited. For example, the catalyst packed tower is packed with the platinum group metal supported catalyst of the present invention, Examples include a method of supplying water to be treated containing hydrogen peroxide to the platinum group metal-supported catalyst of the present invention by supplying the liquid to be treated containing hydrogen peroxide to the catalyst packed tower.

In the case of the above method, water to be treated containing hydrogen peroxide can be passed through the platinum group metal supported catalyst of the present invention at SV = 2000 to 20000 h ⁻¹ , preferably SV = 5000 to 10000 h ^−1. . When the platinum group metal-supported catalyst of the present invention is used, hydrogen peroxide can be decomposed and removed even when water to be treated is passed through with a large SV such that the SV exceeds 2000 h- ¹ . Furthermore, even if SV is 10,000 h- ¹ , if the platinum group metal-supported catalyst of the present invention is used, hydrogen peroxide can be decomposed. The platinum group metal-supported catalyst of the present invention can be used as a particulate anion exchange resin. It shows outstanding performance that far exceeds the processing limit of conventional supported catalysts supporting platinum group metal nanoparticles. The flow rate of the water to be treated containing hydrogen peroxide to the platinum group metal supported catalyst of the present invention is not particularly limited, but is preferably SV = 2000 to 20000 h ⁻¹ , particularly preferably SV = 5000 to 10000 h ^−1. It is. The platinum group metal-supported catalyst of the present invention has a remarkably high hydrogen peroxide decomposing ability. Therefore, it is not necessary to set the water flow rate to an area below SV = 2000 h ^−1, but the water flow rate is set to SV = 2000 h ^−. It may be less than ^one region, even if the water flow rate was region below SV = 2000h ^-1, platinum group metal supported catalyst of the present invention exhibits excellent hydrogen peroxide decomposition ability. On the other hand, when SV exceeds 20000 h ⁻¹ , the water flow differential pressure tends to be too large.

Furthermore, since the platinum group metal-supported catalyst of the present invention has a remarkably high hydrogen peroxide decomposition ability, hydrogen peroxide can be decomposed and removed even if the packed bed height of the catalyst is reduced.

It is preferable that the hydrogen peroxide concentration in the treated water obtained by performing the method for producing hydrogen peroxide-decomposed treated water of the present invention is 1 μg / L or less.

The electronic component cleaning method (I) of the present invention is an electronic component cleaning method of cleaning an electronic component or an electronic component manufacturing instrument with treated water obtained by performing the method for producing hydrogen peroxide decomposition treated water of the present invention. It is.

Embodiments of the electronic component cleaning method (I) according to the present invention will be described with reference to FIGS. FIG. 13 is a schematic flow diagram of the first embodiment of the electronic component cleaning method (I) of the present invention, and FIG. 14 is the second embodiment of the electronic component cleaning method (I) of the present invention. It is a typical flowchart of an example.

As shown in FIG. 13, in the first embodiment of the electronic component cleaning method (I) of the present invention, an object to be cleaned is brought into contact with water containing ozone (hereinafter also referred to as ozone-containing water). The object to be cleaned is brought into contact with the first step 21 for cleaning the object to be cleaned and water containing hydrogen (hereinafter also referred to as hydrogen-containing water), and vibrations of 500 kHz or more are applied. A second process 22 for cleaning the object, a third process 23 for cleaning the object to be cleaned by bringing the object to be cleaned into contact with water containing hydrofluoric acid and hydrogen peroxide, and a process for cleaning the hydrogen-containing water. And a fourth step 24 for cleaning the object to be cleaned while bringing the object into contact with each other and applying a vibration of 500 kHz or more.

The cleaning water supplied to the first step 21 is ozone-containing water prepared by dissolving ozone in the ultrapure water 32. And the ultrapure water contains hydrogen peroxide because it has been subjected to an ultraviolet oxidation process or the like in its manufacturing process. Therefore, in the first embodiment of the electronic component cleaning method (I) of the present invention, before the ozone 33 is dissolved in the ultrapure water 32, the ultrapure water 32 is used as water to be treated. A hydrogen peroxide removal step 25 that performs a method for producing decomposition treated water is performed, ozone 33 is dissolved in the obtained treated water, and supplied as cleaning water in the first step 21.

The cleaning water supplied to the second step 22 is hydrogen-containing water prepared by dissolving hydrogen in the ultrapure water 32. Therefore, in the first embodiment of the electronic component cleaning method (I) of the present invention, before the hydrogen 34 is dissolved in the ultrapure water 32, the ultrapure water 32 is used as water to be treated. A hydrogen peroxide removing step 26 that performs a method for producing decomposition treated water is performed, and hydrogen 34 is dissolved in the obtained treated water and supplied as cleaning water in the second step 22. In the first embodiment of the electronic component cleaning method (I) of the present invention, in the fourth step 24 as well, before the hydrogen 36 is dissolved in the ultrapure water 32, the ultrapure water 32 is used as the water to be treated. The hydrogen peroxide removal step 28 in which the method for producing hydrogen peroxide decomposition treatment water according to the invention is performed, hydrogen 36 is dissolved in the obtained treated water, and supplied as cleaning water in the fourth step 24. It should be noted that the

hydrogen

34 or 36 may be dissolved before the hydrogen

peroxide removing step

26 or 28.

Further, in the first embodiment of the electronic component cleaning method (I) of the present invention, the hydrogen peroxide removing step of performing the method for producing hydrogen peroxide decomposition treated water of the present invention using ultrapure water 32 as water to be treated. 27, hydrofluoric acid and hydrogen peroxide 35 are dissolved in the treated water obtained, and the water containing the obtained hydrofluoric acid and hydrogen peroxide is supplied as cleaning water in the third step 23. You can also.

Then, using the electronic component 20a before cleaning as the object to be cleaned, the first step 21 to the fourth step 24 are sequentially performed to obtain the cleaned electronic component 30a.

As shown in FIG. 14, in the second embodiment of the electronic component cleaning method (I) of the present invention, the object to be cleaned is brought into contact with a liquid containing sulfuric acid and hydrogen peroxide to clean the object to be cleaned. The first step 41 for cleaning, the second step 42 for rinsing with ultrapure water, and the object to be cleaned in contact with water containing hydrofluoric acid (dilute hydrofluoric acid) for cleaning the object to be cleaned A third step 43, a fourth step 44 for rinsing with ultrapure water, a fifth step 45 for cleaning the object to be cleaned by contacting the object to be cleaned with water containing ammonia and hydrogen peroxide, A sixth step 46 for rinsing with ultrapure water, a seventh step 47 for bringing the object to be cleaned into contact with the heated ultrapure water and cleaning the object to be cleaned, and an eighth step 48 for rinsing with ultrapure water And a ninth step for cleaning the cleaning object by bringing the cleaning object into contact with water containing hydrochloric acid and hydrogen peroxide. 9, an eleventh step 50 for rinsing with ultrapure water, an eleventh step 51 for cleaning the object to be cleaned by bringing the object to be cleaned into contact with water containing hydrofluoric acid (dilute hydrofluoric acid), And a twelfth step 52 of rinsing with ultrapure water.

The washing waters 63, 65, 69 and 71 supplied to the third, fifth, ninth and eleventh steps in FIG. 14 are water in which chemicals necessary for each step are dissolved in ultrapure water. Therefore, in the second embodiment of the electronic component cleaning method (I) of the present invention, as in the first embodiment of the electronic component cleaning method (I) of the present invention shown in FIG. Before dissolving the necessary chemicals in each step, a hydrogen peroxide removal step is performed in which the method for producing hydrogen peroxide decomposition treatment water of the present invention is performed using ultrapure water as water to be treated. The chemicals required in the process are dissolved and supplied as cleaning water (cleaning liquid) for each process.

Further, the cleaning

waters

62, 64, 66, 67, 68, 70 and 72 supplied to the second, fourth, sixth, seventh, eighth, tenth and twelfth steps in FIG. 14 are ultrapure water. Therefore, in the second embodiment of the electronic component cleaning method (I) of the present invention, a hydrogen peroxide removal step is performed in which the method for producing hydrogen peroxide decomposition treated water of the present invention is performed using ultrapure water as the treated water. The treated water obtained is supplied as cleaning water for each step.

Then, using the electronic component 20b before cleaning as the object to be cleaned, the first step 41 to the twelfth step 52 are sequentially performed to obtain the cleaned electronic component 30b.

As described above, in the present invention, washing an electronic component or an electronic component manufacturing instrument with treated water obtained by performing the method for producing hydrogen peroxide-decomposed treated water of the present invention means that the peroxidation of the present invention is used. Ultrapure water used for cleaning electronic components or electronic component manufacturing equipment as well as cleaning electronic components or electronic component manufacturing equipment with treated water immediately after the hydrogen decomposition treatment water manufacturing method is performed. In any one or two or more of the steps of producing the hydrogen peroxide decomposition treatment water production method of the present invention, ultrapure water obtained by performing all steps of the ultrapure water production step, It means that an electronic component or an electronic component manufacturing apparatus is cleaned.

<Method for Producing Dissolved Oxygen Removal Water of the Present Invention>
The method for producing treated water for removing dissolved oxygen according to the present invention comprises dissolving dissolved oxygen and hydrogen in treated water containing oxygen in the presence of the first platinum group metal-supported catalyst or the second platinum group metal-supported catalyst. This is a method for producing dissolved oxygen-removed treated water in which dissolved oxygen is removed from water to be treated containing oxygen by reacting to produce water.

The water to be treated containing oxygen is not particularly limited as long as it contains oxygen. For example, the manufacture of electronic parts such as semiconductor manufacturing and the manufacture of ultrapure water for cleaning electronic parts manufacturing equipment, etc. The raw water used in the production process or various kinds of water in the production process thereof, specifically, circulating water of the ultrapure water production subsystem, for example, the outlet water of the ultraviolet oxidizer. Other examples of water to be treated containing dissolved oxygen include water used at power plants, boiler water and cooling water used at various factories.

The dissolved oxygen concentration in the water to be treated containing oxygen is not particularly limited, but is usually 0.01 to 10 mg / L.

The amount of hydrogen to be reacted with dissolved oxygen is not particularly limited, but is 1 to 10 equivalents, preferably 1.1 to 5 equivalents of the oxygen concentration.

The method for reacting dissolved oxygen and hydrogen in the water to be treated containing oxygen in the presence of the platinum group metal supported catalyst of the present invention is not particularly limited. For example, the platinum group metal of the present invention is added to a catalyst packed tower. The supported catalyst is packed, and the treatment liquid containing oxygen is supplied to the catalyst packed tower, and hydrogen gas is injected into the supply pipe of the treatment liquid to dissolve in the platinum group metal supported catalyst of the present invention. Examples include a method of passing hydrogen and water to be treated containing dissolved oxygen.

In the case of the above method, water to be treated containing oxygen can be passed through the platinum group metal supported catalyst of the present invention at SV = 2000 to 20000 h ⁻¹ , preferably SV = 5000 to 10000 h ⁻¹ . When the platinum group metal-supported catalyst of the present invention is used, dissolved oxygen can be removed even when the water to be treated is passed through with a large SV such that the SV exceeds 2000 h- ¹ . Furthermore, even if SV is 10000h- ¹ , if the platinum group metal-supported catalyst of the present invention is used, dissolved oxygen can be removed. The platinum group metal-supported catalyst of the present invention has platinum as a particulate anion exchange resin. Excellent performance, far exceeding the processing limit of conventional supported catalysts supporting group metal nanoparticles. The flow rate of the water to be treated containing oxygen to the platinum group metal supported catalyst of the present invention is not particularly limited, but is preferably SV = 2000 to 20000 h ⁻¹ , particularly preferably SV = 5000 to 10000 h ⁻¹ . . The platinum group metal-supported catalyst of the present invention has a remarkably high ability to remove dissolved oxygen. Even if the water to be treated is passed, dissolved oxygen in the water to be treated can be decomposed.

Furthermore, since the platinum group metal-supported catalyst of the present invention has a remarkably high ability to remove dissolved oxygen, it is possible to remove dissolved oxygen even if the packed bed height of the catalyst is reduced.

It is preferable that the dissolved oxygen concentration in the treated water obtained by the method for producing the treated water for removing dissolved oxygen of the present invention is 10 μg / L or less.

The electronic component cleaning method (II) of the present invention is an electronic component cleaning method of cleaning an electronic component or an electronic component manufacturing instrument with treated water obtained by performing the dissolved oxygen removal treated water manufacturing method of the present invention. is there. *

Oxygen in the air dissolves in the water as dissolved oxygen. Dissolved oxygen is managed as impurities in ultrapure water. As described above, the dissolved oxygen concentration in the treated water (primary pure water) at the secondary pure water system entrance of the ultrapure water production apparatus is usually 100 μg / It is reduced to L or less. Furthermore, it may be controlled to 10 μg / L or less. And the dissolved oxygen concentration in ultrapure water may be controlled to 10 μg / L or less, and further to 1 μg / L or less. On the other hand, in the production process of ultrapure water, oxygen is generated when hydrogen peroxide generated by ultraviolet oxidation or the like is decomposed. Therefore, in the embodiment of the electronic component cleaning method (II) of the present invention, the dissolved oxygen removal step is performed in which the dissolved oxygen removal treatment water production method of the present invention is performed, and the resulting treated water is washed with the electronic components. The cleaning water (cleaning liquid) supplied to each step of the method or ultrapure water for its preparation is used.

The first embodiment of the electronic component cleaning method (II) of the present invention uses the hydrogen peroxide removal steps 25, 26, 27 and 28 in FIG. It replaces the dissolved oxygen removal process which performs the manufacturing method of the removal water of oxygen removal. Then, using the electronic component 20a before cleaning as an object to be cleaned, the first step 21 to the fourth step 24 are sequentially performed to obtain the electronic component 30a after cleaning.

In the second embodiment of the electronic component cleaning method (II) of the present invention, cleaning water (cleaning liquid) 63, 65, 69 and 71 supplied to the third, fifth, ninth and eleventh steps in FIG. Prepared by performing a dissolved oxygen removal step in which the method for producing treated water for removing dissolved oxygen of the present invention is performed using ultrapure water as treated water, and dissolving the necessary chemicals in each step in the obtained treated water, and The cleaning

water

62, 64, 66, 67, 68, 70 and 72 supplied to the second, fourth, sixth, seventh, eighth, tenth and twelfth steps in FIG. It is obtained by performing the dissolved oxygen removal process which performs the manufacturing method of the removal water of the dissolved oxygen removal process of the invention. Then, using the electronic component 20b before cleaning as the object to be cleaned, the first step 41 to the twelfth step 52 are sequentially performed to obtain the cleaned electronic component 30b.

As described above, in the present invention, washing an electronic component or an electronic component manufacturing instrument with treated water obtained by performing the method for producing dissolved oxygen removal treated water of the present invention means that the dissolved oxygen of the present invention is used. Produces ultra-pure water used for cleaning electronic components or electronic component manufacturing equipment, as well as cleaning electronic components or electronic component manufacturing equipment with treated water immediately after the removal treatment water manufacturing method is performed. In any one or two or more of the steps to be performed, the method for producing dissolved oxygen removal treated water of the present invention is performed, and the ultrapure water obtained by performing all steps of the ultrapure water production step This means that the electronic component manufacturing equipment is cleaned.

Next, the present invention will be specifically described with reference to examples, but this is merely an example and does not limit the present invention.

<Production of first monolith anion exchanger (Reference Example 1)>
(Step I; production of monolith intermediate)
19.9 g of styrene, 0.4 g of divinylbenzene, 1.0 g of sorbitan monooleate (hereinafter abbreviated as SMO) and 0.26 g of 2,2′-azobis (isobutyronitrile) were mixed and dissolved uniformly. Next, the styrene / divinylbenzene / SMO / 2,2′-azobis (isobutyronitrile) mixture is added to 180 g of pure water containing 1.8 ml of THF, and a vacuum stirring defoaming mixer which is a planetary stirring device. (EM Co., Ltd.) was used and stirred under reduced pressure in a temperature range of 5 to 20 ° C. to obtain a water-in-oil emulsion. The emulsion was immediately transferred to a reaction vessel, and after sealing, it was allowed to polymerize at 60 ° C. for 24 hours. After completion of the polymerization, the content was taken out, extracted with isopropanol, and then dried under reduced pressure to produce a monolith intermediate having a continuous macropore structure. The average diameter of the openings (mesopores) where the macropores and macropores of the monolith intermediate were measured by mercury porosimetry was 56 μm, and the total pore volume was 7.5 ml / g.

(Manufacture of monoliths)
Next, 49.0 g of styrene, 1.0 g of divinylbenzene, 50 g of 1-decanol, and 0.5 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were mixed and dissolved uniformly (step II). Next, the monolith intermediate was cut into a disk shape having an outer diameter of 70 mm and a thickness of about 20 mm, and 7.6 g was collected. The separated monolith intermediate is put in a reaction vessel having an inner diameter of 90 mm, immersed in the styrene / divinylbenzene / 1-decanol / 2,2′-azobis (2,4-dimethylvaleronitrile) mixture, and removed in a vacuum chamber. After bubbling, the reaction vessel was sealed and allowed to polymerize at 60 ° C. for 24 hours. After completion of the polymerization, the monolith-like contents having a thickness of about 30 mm were taken out, subjected to Soxhlet extraction with acetone, and dried under reduced pressure at 85 ° C. overnight (step III).

FIG. 1 shows the result of observing the internal structure of a monolith (dry body) containing 1.3 mol% of a cross-linking component composed of a styrene / divinylbenzene copolymer obtained by SEM, as described above. The SEM image in FIG. 1 is an image at an arbitrary position on a cut surface obtained by cutting a monolith at an arbitrary position. As is clear from FIG. 1, the monolith has a continuous macropore structure, and the skeleton constituting the continuous macropore structure is much thicker than the SEM image of the known product of Reference Example 3 (FIG. 11). Moreover, the thickness of the wall part which comprises frame | skeleton was thick.

Next, the thickness of the wall part and the area of the skeleton part appearing in the cross section were measured from two SEM images obtained by cutting the obtained monolith at a position different from the above position, excluding subjectivity, and three convenient points. The wall thickness was an average of 8 points obtained from one SEM photograph, and the skeleton area was determined by image analysis. The wall portion has the above definition. Moreover, the skeleton part area was shown by the average of three SEM images. As a result, the average thickness of the wall portion was 30 μm, and the area of the skeleton portion represented by the cross section was 28% in the SEM image. Moreover, the average diameter of the opening of the monolith measured by mercury porosimetry was 31 μm, and the total pore volume was 2.2 ml / g.

(Production of monolith anion exchanger)
The monolith produced by the above method was cut into a disk shape having an outer diameter of 70 mm and a thickness of about 15 mm. To this, 1400 ml of dimethoxymethane and 20 ml of tin tetrachloride were added, and 560 ml of chlorosulfuric acid was added dropwise under ice cooling. After completion of the dropwise addition, the temperature was raised and reacted at 35 ° C. for 5 hours to introduce a chloromethyl group. After completion of the reaction, the mother liquor was extracted with a siphon, washed with a mixed solvent of THF / water = 2/1, and further washed with THF. To this chloromethylated monolith, 1000 ml of THF and 600 ml of a 30% trimethylamine aqueous solution were added and reacted at 60 ° C. for 6 hours. After completion of the reaction, the product was washed with a methanol / water mixed solvent, then washed with pure water and isolated.

The swelling ratio of the obtained monolith anion exchanger before and after the reaction was 1.7 times, and the anion exchange capacity per volume was 0.60 mg equivalent / ml in a wet state with water. The average diameter of the opening of the monolith anion exchanger in the water wet state was estimated from the value of the monolith and the swelling ratio of the monolith anion exchanger in the water wet state to be 54 μm, which constitutes the skeleton obtained by the same method as the monolith. The average wall thickness was 50 μm, the skeleton area was 28% in the photographic region of the SEM photograph, and the total pore volume was 2.2 ml / g. The differential pressure coefficient, which is an index of pressure loss when water is permeated, is 0.017 MPa / m · LV, which is a lower pressure loss than that required for practical use. It was. Furthermore, when the ion exchange zone length regarding the fluoride ion of the monolith anion exchanger was measured, the ion exchange zone length at LV = 20 m / h was 25 mm, and amberlite which is a commercially available strong basic anion exchange resin. Compared with the value (165 mm) of IRA402BL (Rohm and Haas), it was overwhelmingly short.

Next, in order to confirm the distribution state of the quaternary ammonium group in the monolith anion exchanger, the monolith anion exchanger was treated with an aqueous hydrochloric acid solution to form a chloride form, and then the distribution state of chloride ions was observed by EPMA. . FIG. 2 shows the distribution state of chloride ions on the surface of the monolith anion exchanger, and FIG. 3 shows the distribution state of chloride ions in the skeleton cross section. It was uniformly distributed inside, and it was confirmed that quaternary ammonium groups were uniformly introduced into the monolith anion exchanger. In FIG. 3, the chloride ion concentration in the lower part of the skeleton is apparently higher than that in the upper part of the skeleton, but this is not sufficient in cross-sectional flatness at the time of cutting, and the lower part of the skeleton is raised from the upper part of the skeleton This is because the distribution of chloride ions is substantially uniform.

<Production of Second Monolith Anion Exchanger (Reference Example 2)>
(Step I; production of monolith intermediate)
5.29 g of styrene, 0.28 g of divinylbenzene, 1.39 g of sorbitan monooleate (hereinafter abbreviated as SMO) and 0.26 g of 2,2′-azobis (isobutyronitrile) were mixed and dissolved uniformly. Next, the styrene / divinylbenzene / SMO / 2,2′-azobis (isobutyronitrile) mixture was added to 180 g of pure water, and a vacuum stirring defoaming mixer (manufactured by EM Co.) as a planetary stirring device. Was stirred under reduced pressure in a temperature range of 5 to 20 ° C. to obtain a water-in-oil emulsion. This emulsion was quickly transferred to a reaction vessel and allowed to polymerize at 60 ° C. for 24 hours in a static state after sealing. After completion of the polymerization, the content was taken out, extracted with methanol, and then dried under reduced pressure to produce a monolith intermediate having a continuous macropore structure. When the internal structure of the monolith intermediate (dry body) obtained in this way was observed with an SEM image (FIG. 12), the wall portion separating two adjacent macropores was extremely thin and rod-shaped, but the open cell structure The average diameter of the opening (mesopore) where the macropore overlaps with the macropore measured by the mercury intrusion method was 70 μm, and the total pore volume was 17.8 ml / g.

(Manufacture of monoliths)
Next, 39.2 g of styrene, 0.8 g of divinylbenzene, 60 g of 1-decanol, and 0.8 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were mixed and dissolved uniformly (step II). Next, the monolith intermediate was cut into a disk shape having a diameter of 70 mm and a thickness of about 30 mm to obtain 2.4 g. The separated monolith intermediate is placed in a reaction vessel having an inner diameter of 75 mm, immersed in the styrene / divinylbenzene / 1-decanol / 2,2′-azobis (2,4-dimethylvaleronitrile) mixture, and removed in a vacuum chamber. After bubbling, the reaction vessel was sealed and allowed to polymerize at 60 ° C. for 24 hours. After completion of the polymerization, the monolithic contents having a thickness of about 60 mm were taken out, subjected to Soxhlet extraction with acetone, and then dried under reduced pressure at 85 ° C. overnight (step III).

FIG. 7 shows the result of observing the internal structure of the monolith (dry body) containing 1.3 mol% of the crosslinking component composed of the styrene / divinylbenzene copolymer obtained by SEM as described above. As is clear from FIG. 7, the monolith has a co-continuous structure in which the skeleton and the pores are three-dimensionally continuous and both phases are intertwined. Moreover, the thickness of the skeleton measured from the SEM image was 8 μm. Moreover, the average diameter of the three-dimensionally continuous pores of the monolith measured by the mercury intrusion method was 18 μm, and the total pore volume was 2.0 ml / g.

(Production of monolith anion exchanger)
The monolith produced by the above method was cut into a disk shape having a diameter of 70 mm and a thickness of about 15 mm. To this, 1400 ml of dimethoxymethane and 20 ml of tin tetrachloride were added, and 560 ml of chlorosulfuric acid was added dropwise under ice cooling. After completion of the dropping, the temperature was raised and the reaction was carried out at 35 ° C. for 5 hours to introduce a chloromethyl group. After completion of the reaction, the mother liquor was extracted with a siphon, washed with a mixed solvent of THF / water = 2/1, and further washed with THF. To this chloromethylated monolith, 1000 ml of THF and 600 ml of a 30% trimethylamine aqueous solution were added and reacted at 60 ° C. for 6 hours. After completion of the reaction, the product was washed with a methanol / water mixed solvent, then washed with pure water and isolated.

The swelling ratio before and after the reaction of the obtained monolith anion exchanger was 1.6 times, and the anion exchange capacity per volume was 0.44 mg equivalent / ml in a water-wet state. The average diameter of the continuous pores of the monolith ion exchanger in the water wet state was estimated from the value of the monolith and the swelling ratio of the monolith anion exchanger in the water wet state, and was 29 μm. The average thickness of the skeleton was 13 μm, The pore volume was 2.0 ml / g.

Further, the differential pressure coefficient, which is an index of the pressure loss when water is permeated, is 0.040 MPa / m · LV, which is a low pressure loss with no practical problem. Furthermore, when the ion exchange zone length regarding the fluoride ion of the monolith anion exchanger was measured, the ion exchange zone length at LV = 20 m / h was 22 mm, and amberlite which is a commercially available strong basic anion exchange resin. It was overwhelmingly shorter than the value (165 mm) of IRA402BL (made by Rohm and Haas).

Next, in order to confirm the distribution state of the quaternary ammonium group in the monolith anion exchanger, the monolith anion exchanger was treated with an aqueous hydrochloric acid solution to form a chloride form, and then the distribution state of chloride ions was observed by EPMA. . FIG. 8 shows the distribution state of chloride ions on the surface of the monolith anion exchanger, and FIG. 9 shows the distribution state of chloride ions on the cross section of the skeleton. It was uniformly distributed inside, and it was confirmed that quaternary ammonium groups were uniformly introduced into the monolith anion exchanger. In FIG. 9, the chloride ion concentration in the peripheral part of the skeleton is apparently higher than that in the central part of the skeleton, but this is not sufficient in cross-sectional flatness at the time of cutting. It is because it cut | disconnected in the raised state, and the distribution of a chloride ion is substantially uniform.

Reference example 3
(Manufacture of monolithic organic porous material having a continuous macropore structure (known product))
A monolithic organic porous material having a continuous macropore structure was produced according to the production method described in JP-A-2002-306976. That is, 19.2 g of styrene, 1.0 g of divinylbenzene, 1.0 g of SMO and 0.26 g of 2,2′-azobis (isobutyronitrile) were mixed and dissolved uniformly. Next, the styrene / divinylbenzene / SMO / 2,2′-azobis (isobutyronitrile) mixture is added to 180 g of pure water, and a vacuum stirring defoaming mixer (manufactured by EM Corp.) which is a planetary stirring device. Was stirred under reduced pressure in a temperature range of 5 to 20 ° C. to obtain a water-in-oil emulsion. The emulsion was immediately transferred to a reaction vessel, and after sealing, it was allowed to polymerize at 60 ° C. for 24 hours. After completion of the polymerization, the content was taken out, extracted with isopropanol, and then dried under reduced pressure to produce a monolithic organic porous body having a continuous macropore structure.

FIG. 11 shows the result of observation by SEM of the internal structure of the monolith containing 3.3 mol% of a cross-linking component made of a styrene / divinylbenzene copolymer thus obtained. As is clear from FIG. 11, the monolith has a continuous macropore structure, but the thickness of the wall portion constituting the skeleton of the continuous macropore structure was thinner than that of Reference Example 1 (FIG. 1). The average thickness of the wall part measured from the SEM image of the monolith was 5 μm, and the skeleton part area was 10% in the SEM image region. Moreover, the average diameter of the opening of the said monolith measured by the mercury intrusion method was 29 micrometers, and the total pore volume was 8.6 ml / g.

Example 1
(Preparation of first platinum group metal supported catalyst)
The monolith anion exchanger (first monolith anion exchanger) of Reference Example 1 was ion-exchanged into Cl form, cut into a cylindrical shape in a water-wet state, and dried under reduced pressure. The weight of the monolith anion exchanger after drying was 1.2 g. This dried monolith anion exchanger was immersed in dilute hydrochloric acid in which 270 mg of palladium chloride was dissolved, and ion exchanged to the palladium chloride acid form. After completion of the immersion, the monolith anion exchanger was washed several times with pure water, and immersed in an aqueous hydrazine solution for 24 hours for reduction treatment. The chloropalladium acid form monolith anion exchanger was brown, whereas the monolith anion exchanger after the reduction treatment was colored black, suggesting the formation of palladium nanoparticles. The first palladium nanoparticle-supported catalyst a thus obtained was washed several times with pure water and dried.

The amount of palladium nanoparticles supported on the dried first palladium nanoparticle-supported catalyst a was 10.9% by weight. In order to measure the average particle diameter of the supported palladium nanoparticles, observation with a transmission electron microscope (TEM) was performed. The obtained TEM image is shown in FIG. The average particle diameter of the palladium nanoparticles was 5 nm. A palladium nanoparticle-supported catalyst a in a dry state was packed in a column having an inner diameter of 10 mm, and an aqueous sodium hydroxide solution was passed through to convert the monolith anion exchanger as a carrier into OH form, which was used for evaluation of hydrogen peroxide decomposition characteristics. The packed bed height of the first palladium nanoparticle-supported catalyst a was 11 mm. At this time, the supported amount of palladium nanoparticles with respect to the water-wet resin volume was 9.7 g-Pd / LR (weight of palladium supported per liter of palladium nanoparticle-supported catalyst).

(Evaluation of catalyst)
Ultrapure water containing 15 to 30 μg / L of hydrogen peroxide was passed through the first palladium nanoparticle-supported catalyst a packed in a column having an inner diameter of 10 mm for 27 hours at SV = 5000 h ^{−1 for} 27 hours, Sample water was collected at the column outlet and the hydrogen peroxide concentration was measured. As a result, the hydrogen peroxide concentration in the sample water collected at the column outlet was less than 1 μg / L, and the hydrogen peroxide was decomposed and removed. Next, the SV was set to 10,000 h ⁻¹ and the same processing was performed. The hydrogen peroxide concentration in the sample water sampled at the column outlet is very fast as SV is 10,000 h ⁻¹ and the catalyst packed bed height is as thin as 11 mm, and is less than 1 μg / L. It was disassembled and removed.

Example 2
(Preparation of second platinum group metal supported catalyst)
As the catalyst carrier, the monolith anion exchanger (second monolith anion exchanger) of Reference Example 2 was used in place of the monolith anion exchanger (first monolith anion exchanger) of Reference Example 1 and was cut out. The monolith anion exchanger (second monolith anion) of Reference Example 2 was prepared in the same manner as in Example 1, except that the dry weight of the monolith anion exchanger was changed to 1.4 g instead of 1.2 g. The palladium nanoparticles were supported on the exchanger to obtain a second palladium nanoparticle-supported catalyst a.

The supported amount of palladium nanoparticles supported on the dried second palladium nanoparticle-supported catalyst a was 9.8% by weight. In order to measure the average particle diameter of the supported palladium nanoparticles, observation with a transmission electron microscope (TEM) was performed. The obtained TEM image is shown in FIG. The average particle diameter of the palladium nanoparticles was 3 nm. A column with a diameter of 10 mm is packed with a second palladium nanoparticle-supported catalyst in a dry state, and an aqueous sodium hydroxide solution is passed through to convert the monolith anion exchanger as a carrier into OH form, which is used for evaluation of hydrogen peroxide decomposition characteristics. It was. The packed bed height of the catalyst was 13 mm. At this time, the supported amount of palladium nanoparticles with respect to the water-wet resin volume was 8.7 g-Pd / LR.

(Evaluation of catalyst)
Except that the second palladium nanoparticle-supported catalyst a was used in place of the first palladium nanoparticle-supported catalyst as the catalyst, the excess of the second palladium nanoparticle-supported catalyst a was the same as in Example 1. The hydrogen oxide decomposition effect was evaluated. As a result, in either case that passed through the ultra-pure water at SV = 5000h ^-1 and 10000h ^-1, the hydrogen peroxide concentration of the sample water and water sampling in the column outlet is less than 1 [mu] g / L, hydrogen peroxide It was disassembled and removed.

Example 3
The weight of dried first monolith anion exchanger is changed to 1.2 g instead of 1.7 g, and 2.5 mg of palladium chloride is dissolved instead of dissolving 270 mg of palladium chloride. Except for the above, palladium nanoparticles were supported on the monolith anion exchanger of Reference Example 1 (first monolith anion exchanger) in the same manner as in Example 1 to obtain a first palladium nanoparticle-supported catalyst b.

The supported amount of palladium nanoparticles supported on the obtained first palladium nanoparticle-supported catalyst b in a dry state was 0.05% by weight. For the evaluation of hydrogen peroxide decomposition characteristics, the first palladium nanoparticle-supported catalyst b in a dry state is packed in a column having an inner diameter of 10 mm, and an aqueous sodium hydroxide solution is passed to form a monolith anion exchanger as a carrier in OH form. Using. The packed bed height of the catalyst was 19 mm. At this time, the supported amount of palladium nanoparticles with respect to the water-wet resin volume was 0.07 g-Pd / LR.

(Evaluation of catalyst)
As the catalyst, the first palladium nanoparticle-supported catalyst b was prepared in the same manner as in Example 1 except that the first palladium nanoparticle-supported catalyst b was used instead of the first palladium nanoparticle-supported catalyst a. The hydrogen peroxide decomposition effect was evaluated. When water was passed at SV = 5000 h ⁻¹ , the hydrogen peroxide concentration in the sample water collected at the column outlet was less than 1 μg / L, and the hydrogen peroxide was decomposed and removed. Next, SV was set to 10,000 h ⁻¹ and the same processing was performed. Although the concentration of hydrogen peroxide in the sample water collected at the column outlet is 1.7 μg / L, the amount of palladium nanoparticles supported is extremely low, 0.07 g-Pd / LR, and thus the peroxide is oxidized. The result with high hydrogenolysis effect was obtained.

Comparative Example 1
Moisture retention capacity is 60 to 70% on the basis of OH type, and palladium nanoparticle is supported by a well-known method on particulate strong base anion exchange resin (type I) in gel form. A resin catalyst was obtained. The Cl-type particulate anion exchange resin was immersed in an aqueous hydrochloric acid solution of palladium chloride, washed with water, and then reduced with an aqueous hydrazine solution. An aqueous sodium hydroxide solution was passed through to convert the particulate anion exchange resin into OH form, which was used for evaluation of hydrogen peroxide decomposition characteristics. At this time, the supported amount of palladium nanoparticles was 0.4% by weight in a dry state and 970 mg-Pd / LR in a water-wet state. An OH-type particulate ion exchange resin carrying palladium was packed in a column with an inner diameter of 25 mm in 40 mL (layer height 80 mm), and an experiment for reducing hydrogen peroxide was conducted in the same manner as in Example 1.

(Evaluation of catalyst)
As the catalyst, the above-described palladium nanoparticle-supported granular ion exchange resin catalyst was used instead of the first palladium nanoparticle-supported catalyst a, and ultrapure water was passed through at SV = 1500 h ⁻¹ and 2500 h ^−1. In the same manner as in Example 1, the hydrogen peroxide decomposition effect of the palladium nanoparticle-supported granular ion exchange resin catalyst was evaluated. As a result, the hydrogen peroxide concentrations in the sample water collected at the column outlet were less than 1 μg / L and 1.6 μg / L, respectively. At SV = 1500 h ⁻¹ , hydrogen peroxide was less than 1 μg / L, but when SV was increased to 2500 h ⁻¹ , hydrogen peroxide leaked into the treated water. In this way, in the catalyst in which palladium nanoparticles are supported on the particulate anion exchange resin that is the prior art, even if the conditions for easily removing hydrogen peroxide such as SV slower than the example and the high catalyst packed bed height are set, At SV = 2500 h ⁻¹ , hydrogen peroxide leaked.

Comparative Example 2
By using only the monolith anion exchanger (first monolith anion exchanger) of Reference Example 1 without supporting palladium nanoparticles, the hydrogen peroxide decomposition effect at SV = 10000 h ^{−1 was obtained} in the same manner as in Example 1. evaluated. As a result, the decomposition effect of hydrogen peroxide was not recognized.

<Production of monolith according to first monolith anion exchanger (Reference Examples 4 to 13)>
(Manufacture of monoliths)
Table 1 shows the amount of styrene used, the type and amount of crosslinking agent, the type and amount of organic solvent, the porous structure of the monolith intermediate that coexists during styrene and divinylbenzene impregnation polymerization, the crosslinking density and the amount used. A monolith was produced in the same manner as in Reference Example 1 except for the change. The results are shown in Tables 1 and 2. From the SEM images (not shown) of Reference Examples 4 to 13 and Table 2, the average diameter of the monolithic openings of Reference Examples 4 to 13 is as large as 22 to 70 μm, and the average thickness of the walls constituting the skeleton is also 25 to It was as thick as 50 μm, and the skeletal area was 26-44% in the SEM image area, which was a thick monolith. In Table 1, the preparation column shows, in order from the left, the vinyl monomer used in Step II, the crosslinking agent, the monolith intermediate obtained in Step I, and the organic solvent used in Step II. The mesopore diameter, wall thickness, skeleton diameter (thickness), and pore diameter shown in the following table are average values.

<Production of first monolith anion exchanger (Reference Example 14)>
(Manufacture of monoliths)
A monolith was produced in the same manner as in Reference Example 1 except that the amount of styrene used, the amount of crosslinking agent used, and the amount of organic solvent used were changed to the amounts shown in Table 1. The results are shown in Tables 1 and 2. In the monolith of Reference Example 14, an organic porous body having a thick wall portion with an average diameter of the opening of the overlapping portion of the macropores as large as 38 μm and an average thickness of the wall portion constituting the skeleton of 25 μm was obtained.

The swelling ratio of the obtained monolith anion exchanger before and after the reaction was 1.6 times, and the anion exchange capacity per volume was 0.56 mg equivalent / ml in a water wet state. The average diameter of the opening of the monolith anion exchanger in the water wet state was estimated from the value of the monolith and the swelling ratio of the monolith anion exchanger in the water wet state, and was 61 μm, and constituted the skeleton obtained by the same method as the monolith. The average wall thickness was 40 μm, the skeleton area was 26% in the photographic region of the SEM photograph, and the total pore volume was 2.9 ml / g. The differential pressure coefficient, which is an index of pressure loss when water is permeated, is 0.020 MPa / m · LV, which is a lower pressure loss than that required for practical use. It was.

Next, in order to confirm the distribution state of the quaternary ammonium group in the monolith anion exchanger, the monolith anion exchanger was treated with an aqueous hydrochloric acid solution to form a chloride form, and then the distribution state of chloride ions was observed by EPMA. . As a result, it was confirmed that the chloride ions were uniformly distributed not only on the skeleton surface of the monolith anion exchanger but also inside the skeleton, and the quaternary ammonium groups were uniformly introduced into the monolith anion exchanger. It was.

<Production of Second Monolith Anion Exchanger (Reference Example 15)>
(Step I; production of monolith intermediate)
5.4 g of styrene, 0.17 g of divinylbenzene, 1.4 g of sorbitan monooleate (hereinafter abbreviated as SMO) and 0.26 g of 2,2′-azobis (isobutyronitrile) were mixed and dissolved uniformly. Next, the styrene / divinylbenzene / SMO / 2,2′-azobis (isobutyronitrile) mixture was added to 180 g of pure water, and a vacuum stirring defoaming mixer (manufactured by EM Co.) as a planetary stirring device. Was stirred under reduced pressure in a temperature range of 5 to 20 ° C. to obtain a water-in-oil emulsion. This emulsion was quickly transferred to a reaction vessel and allowed to polymerize at 60 ° C. for 24 hours in a static state after sealing. After completion of the polymerization, the content was taken out, extracted with methanol, and then dried under reduced pressure to produce a monolith intermediate having a continuous macropore structure. The internal structure of the monolith intermediate (dry body) thus obtained was observed by SEM images (not shown), and the wall part that divides two adjacent macropores was extremely thin and rod-shaped, but the open-cell structure The average diameter of the openings (mesopores) where the macropores overlap with each other as measured by the mercury intrusion method was 70 μm, and the total pore volume was 21.0 ml / g.

(Manufacture of monocontinuous monolith)
Subsequently, 76.0 g of styrene, 4.0 g of divinylbenzene, 120 g of 1-decanol, and 0.8 g of 2,2′-azobis (2,4-dimethylvaleronitrile) were mixed and dissolved uniformly (step II). Next, the monolith intermediate was cut into a disk shape having a diameter of 70 mm and a thickness of about 40 mm to fractionate 4.1 g. The separated monolith intermediate is placed in a reaction vessel having an inner diameter of 75 mm, immersed in the styrene / divinylbenzene / 1-decanol / 2,2′-azobis (2,4-dimethylvaleronitrile) mixture, and removed in a vacuum chamber. After bubbling, the reaction vessel was sealed and allowed to polymerize at 60 ° C. for 24 hours. After completion of the polymerization, the monolithic contents having a thickness of about 60 mm were taken out, subjected to Soxhlet extraction with acetone, and then dried under reduced pressure at 85 ° C. overnight (step III).

When the internal structure of the monolith (dry body) containing 3.2 mol% of the crosslinking component composed of the styrene / divinylbenzene copolymer obtained in this way was observed by SEM, the monolith had a skeleton and pores, respectively. It was a three-dimensional continuous structure with both phases intertwined. Moreover, the average thickness of the skeleton measured from the SEM image was 10 μm. Further, the average diameter of the three-dimensionally continuous pores of the monolith measured by mercury porosimetry was 17 μm, and the total pore volume was 2.9 ml / g. The results are summarized in Tables 3 and 4. In Table 4, the thickness of the skeleton is represented by the average diameter of the skeleton.

(Production of monolith anion exchanger having a co-open cell structure)
The monolith produced by the above method was cut into a disk shape having a diameter of 70 mm and a thickness of about 15 mm. To this, 1400 ml of dimethoxymethane and 20 ml of tin tetrachloride were added, and 560 ml of chlorosulfuric acid was added dropwise under ice cooling. After completion of the dropping, the temperature was raised and the reaction was carried out at 35 ° C. for 5 hours to introduce a chloromethyl group. After completion of the reaction, the mother liquor was extracted with a siphon, washed with a mixed solvent of THF / water = 2/1, and further washed with THF. To this chloromethylated monolith, 1000 ml of THF and 600 ml of a 30% trimethylamine aqueous solution were added and reacted at 60 ° C. for 6 hours. After completion of the reaction, the product was washed with a methanol / water mixed solvent, then washed with pure water and isolated.

The swelling ratio before and after the reaction of the obtained monolith anion exchanger was 1.5 times, and the anion exchange capacity per volume was 0.54 mg equivalent / ml in a water-wet state. The average diameter of the continuous pores of the monolithic ion exchanger in the water wet state was estimated from the value of the monolith and the swelling ratio of the monolith anion exchanger in the water wet state, and was 26 μm, the average thickness of the skeleton was 15 μm, The pore volume was 2.9 ml / g.

Further, the differential pressure coefficient, which is an index of pressure loss when water is permeated, is 0.045 MPa / m · LV, which is a low pressure loss that has no practical problem. Furthermore, when the ion exchange zone length regarding the fluoride ion of the monolith anion exchanger was measured, the ion exchange zone length at LV = 20 m / h was 20 mm, and amberlite which is a commercially available strong basic anion exchange resin. In addition to being overwhelmingly shorter than the value of IRA402BL (Rohm and Haas) (165 mm), it was also shorter than the value of a monolithic porous anion exchanger having a conventional open cell structure. The results are summarized in Table 5. Moreover, the internal structure of the obtained monolith anion exchanger having a co-continuous structure was observed by an SEM image (not shown).

Next, in order to confirm the distribution state of the quaternary ammonium group in the monolith anion exchanger, the monolith anion exchanger was treated with an aqueous hydrochloric acid solution to form a chloride form, and then the distribution state of chloride ions was observed by EPMA. . As a result, it was confirmed that chloride ions were uniformly distributed not only on the surface of the monolith anion exchanger but also inside, and that quaternary ammonium groups were uniformly introduced into the monolith anion exchanger.

<Production of Second Monolith Anion Exchanger (Reference Examples 16 and 17)>
(Manufacture of monolith with co-continuous structure)
Except for changing the amount of styrene used, the amount of crosslinking agent used, the amount of organic solvent used, the porous structure of the monolith intermediate coexisting during styrene and divinylbenzene impregnation polymerization, the crosslinking density and the amount used as shown in Table 3. A monolith having a co-continuous structure was produced in the same manner as in Reference Example 15. When the internal structure of the monolith (dried body) was observed by SEM (not shown), the monolith had a co-continuous structure in which the skeleton and the vacancies were each three-dimensionally continuous and the two phases were intertwined. The results are shown in Tables 3 and 4.
Table 1, Table 2, Table 3, and Table 4 are sequentially shown below in order.

The monoliths obtained in the above Reference Examples 4 to 13 and Reference Examples 16 to 17 can be prepared by appropriately applying known methods, for example, by the method shown in Reference Example 1 or Reference Example 2, for example. Can be introduced. Further, the monolith anion exchanger obtained by introducing an anion exchange group into the monoliths obtained in Reference Examples 4 to 13 and Reference Examples 16 to 17 and the monolith anion exchanger obtained in Reference Examples 14 and 15 are known. By appropriately applying the above method, for example, the platinum group metal nanoparticles can be supported by the method shown in Example 1 or Example 2.

Example 4
Palladium nanoparticles were added to the monolith anion exchanger (first monolith anion exchanger) of Reference Example 1 in the same manner as in Example 1 except that 190 mg of palladium chloride was dissolved instead of 270 mg of palladium chloride. To obtain a first palladium nanoparticle-supported catalyst c.

The amount of palladium nanoparticles supported on the dried first palladium nanoparticle-supported catalyst c was 7.4% by weight. The first palladium nanoparticle-supported catalyst c in a dry state was packed in a column having an inner diameter of 10 mm and used for evaluation of dissolved oxygen removal characteristics. The packed bed height of the catalyst was 20 mm. At this time, the supported amount of palladium nanoparticles with respect to the water-wet resin volume was 10.5 g-Pd / LR.

(Evaluation of catalyst)
Ultrapure water adjusted to a dissolved oxygen concentration of 32 μg / L and a dissolved hydrogen concentration of 11 μg / L was passed through the first palladium nanoparticle-supported catalyst c packed in a column having an inner diameter of 10 mm at SV = 7500 h ⁻¹ . The measurement was performed until the dissolved oxygen concentration in the treated water at the column outlet was stabilized. As a result, the dissolved oxygen concentration at the column outlet was reduced to 3.8 μg / L.

(Comparative Example 3)
Cl form in which palladium is supported on 910 mg-Pd / LR in a wet state in a particulate strongly basic anion exchange resin (Cl form) having a moisture retention capacity of 60 to 70% on the basis of OH form. A catalyst resin was prepared. Catalyst evaluation was performed in the same manner as in Example 4 except that this Cl-type catalyst resin was passed through the column having an inner diameter of 10 mm with a packed bed height of 360 mm and a flow rate of SV430. As a result, the dissolved oxygen concentration at the column outlet when the treated water was stabilized was 4.1 μg / L. The evaluation results in Example 4 and Comparative Example 3 are summarized in Table 5.
Table 5 is shown below.

Example 4 has a very high flow rate with SV7500, and even though the flow rate of water per mass of the supported palladium metal catalyst is higher in Example 4 than in Comparative Example 3, Comparative Example 3 As a result, treated water with a dissolved oxygen concentration of about the same level was obtained. Therefore, if the platinum group metal supported catalyst of the present invention is used, it is possible to effectively remove dissolved oxygen even at a high flow rate and a low resin layer height. Can be reduced.

DESCRIPTION OF SYMBOLS 1 Skeletal phase 2 Pore phase 10 Monolith 11 Image area 12 Skeletal part shown in cross section 13 Macropore

Claims

A platinum group metal-supported catalyst in which platinum group metal nanoparticles having an average particle diameter of 1 to 100 nm are supported on an organic porous anion exchanger,
The organic porous anion exchanger is a continuous macropore structure in which cellular macropores overlap each other, and the overlapped portion is an opening having an average diameter of 30 to 300 μm in a wet state of water, and has a total pore volume of 0.5 to 5 ml. / G, an anion exchange capacity per volume in a wet state of water of 0.4 to 1.0 mg equivalent / ml, anion exchange groups are uniformly distributed in the organic porous anion exchanger, and the continuous In the SEM image of the cut surface of the macropore structure (dried body), the skeleton area that appears in the cross section is 25 to 50% in the image region,
The supported amount of the platinum group metal is 0.004 to 20% by weight in a dry state;
A platinum group metal supported catalyst.
A platinum group metal-supported catalyst in which platinum group metal nanoparticles having an average particle diameter of 1 to 100 nm are supported on an organic porous anion exchanger,
The organic porous anion exchanger has an average thickness composed of an aromatic vinyl polymer containing 0.3 to 5.0 mol% of a cross-linking structural unit among all the structural units into which an anion exchange group has been introduced. A co-continuous structure comprising a three-dimensionally continuous skeleton of 1 to 60 μm and three-dimensionally continuous pores having an average diameter of 10 to 100 μm in a wet state between the skeletons. The volume is 0.5 to 5 ml / g, the anion exchange capacity per volume under water wet condition is 0.3 to 1.0 mg equivalent / ml, and an anion exchange group is contained in the organic porous anion exchanger. Evenly distributed,
The supported amount of the platinum group metal is 0.004 to 20% by weight in a dry state;
A platinum group metal supported catalyst.
The platinum group metal-supported catalyst according to claim 1 or 2 is brought into contact with water to be treated containing hydrogen peroxide to decompose and remove hydrogen peroxide in the water to be treated containing hydrogen peroxide. A method for producing hydrogen peroxide decomposition-treated water.
The method for producing hydrogen peroxide-decomposed water according to claim 3, wherein the organic porous anion exchanger is in the OH form.
5. The hydrogen peroxide solution according to claim 3, wherein the platinum group metal-supported catalyst is brought into contact with water to be treated containing hydrogen peroxide at SV = 2000 to 20000 h −1 . A method for producing cracked water.
An electronic component cleaning method, comprising: cleaning an electronic component or an electronic component manufacturing instrument with treated water obtained by performing the method for producing hydrogen peroxide decomposition treated water according to any one of claims 3 to 5. .
In the presence of the platinum group metal-supported catalyst according to claim 1 or 2, the oxygen is contained by reacting hydrogen with dissolved oxygen in the water to be treated containing oxygen to produce water. A method for producing dissolved oxygen-removed treated water, wherein dissolved oxygen is removed from water to be treated.
The method for producing dissolved oxygen-removed treated water according to claim 7, wherein the organic porous anion exchanger is in the OH form.
9. The treated water for removing dissolved oxygen according to claim 7, wherein the water to be treated containing oxygen is brought into contact with the platinum group metal supported catalyst at SV = 2000 to 20000 h −1. Manufacturing method.
10. A method for cleaning an electronic component, characterized in that the electronic component or an electronic component manufacturing apparatus is cleaned with the treated water obtained by performing the dissolved oxygen removal treated water production method according to any one of claims 7 to 9.