JP2017064602A - Siloxane compound removal facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a siloxane compound removal facility which can efficiently remove a siloxane compound in a low concentration and which can be easily made.SOLUTION: A siloxane compound removal facility comprises: a siloxane compound removal chemical filter which uses, as an absorbent, an inorganic silica porous material that has 7 or less of the pH of a mixture (content: 5 wt.%) when mixed with pure water; and an inhibitory substance removal chemical filter installed on an upstream side of the siloxane compound removal chemical filter which removes an inhibitory substance causing degradation in performance of a siloxane compound removal ability of the siloxane compound removal chemical filter.SELECTED DRAWING: None

Description

  The present invention relates to an installation for removing a siloxane compound from a fluid (particularly in the air). The present invention also relates to a fluid purification method using the equipment.

  In living environments, siloxane compounds exist in all environments. For example, cyclic siloxane compounds are used for packing materials and sealing materials present in buildings such as ordinary households and clean rooms, adhesives used in construction sites, shampoos, cosmetics, etc., for all substances present in the living environment. It has been.

  In addition, it is known that a disilazane compound such as hexamethyldisilazane (HMDS) is used as a photoresist adhesive in the exposure process of the semiconductor manufacturing process. HMDS, for example, is sprayed as a gas on the wafer surface to replace the hydroxyl group on the wafer surface with a trimethylsilanol group, thereby hydrophobizing the wafer surface and improving the adhesion with the resist agent on the wafer surface. . However, when a cyclic siloxane compound is present in the air, if the cyclic siloxane compound adheres to the wafer surface, the characteristics of the semiconductor are changed, and the product yield may be reduced even at a low concentration.

  In order to remove the cyclic siloxane compound, a chemical filter using activated carbon as an adsorbent is usually used. As an adsorbent using activated carbon, for example, activated carbon for removing siloxane having two types of activated carbons having different average pore diameters is known (see Patent Document 1).

  In addition to activated carbon, resins or porous materials into which acidic functional groups such as sulfonic acid groups are introduced are used as adsorbents for cyclic siloxane compounds. As such an adsorbent, for example, a siloxane remover containing a resin having a sulfonic acid group (see Patent Document 2), a porous material in which a sulfonic acid group-modified metal oxide sol is attached to a porous material (Patent Document) 3, 4), an inorganic porous material having an average pore diameter of 3 to 20 nm, a siloxane remover containing an acidic compound having a dissociation index of 2.2 or less and a molecular weight of 1000 or less (see Patent Document 5), etc. It has been known. It is described that siloxanes can be selectively and efficiently removed by using a resin or a porous material into which such an acidic functional group is introduced as an adsorbent.

JP 2005-177737 A JP 2011-212565 A JP 2013-103153 A JP2013-103154A JP-A-2015-44175

  However, as in Patent Document 1, when activated carbon is used as the adsorbent, siloxanes once adsorbed may be desorbed.

  In addition, the cyclic siloxane compound is often present in the atmosphere together with other gas components such as an organic gas component in a normal environment. For this reason, when there are many other gas components, in the adsorbent using activated carbon as described in Patent Document 1, the removal of the cyclic siloxane compound and the removal of the other gas components are competing, The removal efficiency (removal performance or removal capability) of the cyclic siloxane compound varies depending on the amount of other gas components present. Furthermore, the amount of other gas components present in the atmosphere often varies from day to day. For this reason, since the quantity of the cyclic siloxane compound which activated carbon removes fluctuates every day, it was difficult to predict the remaining life of the adsorbent using activated carbon and the filter using the adsorbent.

  In Patent Document 2, a strong acid ion exchange resin is used. However, a resin having a sulfonic acid group usually has a low adsorption capability of the siloxane compound, and there is a problem that the siloxane gas cannot be sufficiently removed regardless of whether the resin is supported on the porous carrier. Furthermore, since the resin has a large molecular weight, the resin is always present in the vicinity of the sulfonic acid group, but the resin has a low adsorption ability of the siloxane compound, and the reaction between the sulfonic acid group and the siloxane compound proceeds slowly. There is a problem of detachment.

  In Patent Document 2, cyclic siloxanes are polymerized and adsorbed by a strong acid ion exchange resin, and in Patent Document 5, the adsorbed siloxane gas is activated by an acidic compound and is not activated. Adsorbed by reacting with gas. Thus, cited documents 2 and 5 describe that siloxane compounds react with each other and adsorb. However, when the concentration of the siloxane compound in the air is very low, the reaction between the siloxane compounds hardly occurs, and this method does not necessarily provide sufficient removal efficiency.

  In Patent Documents 3 and 4, a material obtained by attaching a sulfonic acid group-modified metal oxide sol to a porous material is used. However, in order to obtain such a sulfonic acid group-modified metal oxide sol, it is necessary to prepare by a complicated process, and an adsorbent and a chemical filter that can efficiently remove a siloxane compound cannot be easily obtained.

  For this reason, the present condition is that the chemical filter which can remove a siloxane compound efficiently in a low concentration environment and can be obtained easily is calculated | required.

Accordingly, an object of the present invention is to provide a siloxane compound removal facility that can efficiently remove a siloxane compound in a low concentration environment and can be easily obtained.
Another object of the present invention is to provide a siloxane compound removal facility capable of selectively removing a siloxane compound. Another object of the present invention is to provide a fluid purification method capable of efficiently removing a siloxane compound present in a fluid (particularly in the air).

  As a result of intensive studies to achieve the above object, the present inventors have found that a siloxane compound removing chemical filter using an inorganic silica-based porous material having a pH of 7 or less as a water mixture with pure water as an adsorbent, According to the equipment having the chemical filter for removing an inhibitory substance that reduces the siloxane compound removal ability of the siloxane compound removal chemical filter installed upstream thereof, the siloxane compound in the fluid (especially in the air) We found that it can be removed efficiently. The present invention has been completed based on these findings.

  That is, the present invention is a siloxane compound removal chemical filter using an inorganic silica-based porous material having a pH of 7 or less as a water mixture (content ratio: 5 wt%) obtained by mixing with pure water as an adsorbent, A siloxane compound having an inhibitor removal chemical filter installed upstream of the siloxane compound removal chemical filter, which removes an inhibitor that lowers the siloxane compound removal ability of the siloxane compound removal chemical filter. Provide removal equipment.

  The inhibitor removing chemical filter may be at least one selected from the group consisting of a basic substance removing chemical filter and a silanol compound removing chemical filter.

  The inorganic silica-based porous material is zeolite, silica gel, silica alumina, aluminum silicate, porous glass, diatomaceous earth, hydrous magnesium silicate clay mineral, allophane, imogolite, acidic clay, activated clay, activated bentonite, mesoporous silica, It may be at least one inorganic silica-based porous material selected from the group consisting of aluminosilicate, fumed silica, fly ash, and clinker ash.

  As the adsorbent, another adsorbent may be used together with the inorganic silica-based porous material whose pH of the water mixture (content ratio: 5 wt%) is 7 or less.

  As the inorganic silica-based porous material, at least one selected from the group consisting of synthetic zeolite, diatomaceous earth, silica gel, acid clay, and activated clay whose pH of the water mixture (content ratio: 5 wt%) is 7 or less. , 10% by weight or more based on the total weight of the adsorbent may be contained.

  The inorganic silica-based porous material includes a synthetic zeolite having a water mixture (content ratio: 5 wt%) having a pH of 7 or less, and the synthetic zeolite is A-type, ferrierite, MCM-22, ZSM-5, ZSM- 11, synthetic zeolite having at least one kind of framework structure selected from the group consisting of SAPO-11, mordenite, beta type, X type, Y type, L type, chabazite, and offretite.

  Moreover, this invention provides the fluid purification | cleaning method characterized by removing a siloxane compound using the said siloxane compound removal equipment.

  According to the siloxane compound removal equipment of the present invention, the once-adsorbed siloxane compound does not desorb again, so that the removal effect lasts longer than that of activated carbon. Moreover, since it is not necessary to react siloxane compounds in the removal of a siloxane compound, it can remove efficiently also in a low concentration environment. Furthermore, the removal effect of the siloxane compound lasts for a long time because the siloxane compound removal ability is not lowered by an inhibitor that lowers the siloxane compound removal ability. Further, the adsorbent, the chemical filter, and the siloxane compound removal equipment can be produced without the need for complicated processes and can be easily obtained.

  Furthermore, according to the siloxane compound removal equipment of the present invention, it is easy to selectively remove the siloxane compound. For this reason, it is easy to efficiently remove the siloxane compound even in an environment where other gas components exist together with the siloxane compound. This also makes it relatively easy to predict the remaining life of the siloxane compound removal equipment.

  Further, according to the siloxane compound removal equipment of the present invention, in particular, since the siloxane compound in the air can be removed extremely efficiently, the amount of the adsorbent used can be made very small, and the filter base material can be used. The number of sheets can be reduced, and there is a tendency that energy saving, low cost, and space saving can be achieved.

It is the schematic of the aeration test apparatus used in the Example. It is a partial schematic sectional drawing of the aeration test apparatus used in the Example. It is a graph (relationship between pH of a water mixture of zeolite and removal efficiency) showing aeration test results of Example 1. It is a graph (Relationship between pH and removal efficiency of water mixture of silica gel, acid clay, activated clay, and diatomaceous earth) showing the results of the aeration test of Example 1. It is a graph (relationship between pH and removal efficiency of water mixture of zeolite and diatomaceous earth) showing the aeration test result of Example 4. It is a graph (removal efficiency (time change) before and after ammonia treatment of synthetic zeolite) showing aeration test results of Example 6. It is a graph (The removal efficiency (time change) before and behind ammonia treatment of silica gel, activated clay, and diatomaceous earth) which shows the aeration test result of Example 7. It is a graph which shows the ventilation test result of Example 8 (removal efficiency (time change) before and after the TMS process of synthetic zeolite).

  The siloxane compound removing equipment of the present invention is a siloxane compound removing chemical using an inorganic silica porous material having a pH of 7 or less as a water mixture (content ratio: 5 wt%) obtained by mixing with pure water as an adsorbent. A filter, and an inhibitor removal chemical filter that removes an inhibitor that lowers the siloxane compound removal ability of the siloxane compound removal chemical filter. In the present specification, the above-mentioned “chemical filter for removing a siloxane compound using an inorganic silica-based porous material having a pH of 7 or less as a water mixture (content ratio: 5 wt%) obtained by mixing with pure water” as an adsorbent. May be referred to as “the chemical filter of the present invention”. Further, in the present specification, the above-mentioned “chemical filter for removing an inhibitory substance that removes an inhibitor that lowers the ability to remove a siloxane compound of a chemical filter for removing a siloxane compound”, that is, “the ability to remove a siloxane compound of a chemical filter of the present invention is reduced. The “inhibitory substance removing chemical filter for removing the inhibiting substance” may be simply referred to as “inhibitory substance removing chemical filter”.

[Chemical filter of the present invention]
The chemical filter of the present invention is a siloxane compound removing chemical filter using an inorganic silica-based porous material whose pH of a water mixture (content ratio: 5 wt%) obtained by mixing with pure water is 7 or less as an adsorbent. It is. In the present specification, an adsorbent using an inorganic silica-based porous material whose pH of a water mixture (content ratio: 5 wt%) obtained by mixing with pure water is 7 or less is referred to as “the adsorbent of the present invention. May be called. In the present specification, “pH of water mixture” means “pH of water mixture (content ratio: 5 wt%)” unless otherwise specified.

(Adsorbent of the present invention)
The chemical filter of the present invention uses an inorganic silica-based porous material as an essential adsorbent. As for the said inorganic silica type porous material, only 1 type may be used and 2 or more types may be used.

  The inorganic silica-based porous material has a pH of a water mixture (content ratio: 5 wt%) obtained by mixing with pure water of 7 or less (for example, 3 to 7), preferably less than 7 (for example, 3 or more). Less than 7), more preferably 3 to 6.5, and still more preferably 4 to 6. When the pH is 7 or less, the siloxane compound can be removed with high efficiency.

  In this specification, the pH of the water mixture (content ratio: 5 wt%) obtained by mixing with pure water is the content ratio of the substance (target substance) mixed in the water mixture with respect to the entire water mixture. The pH when measured under the condition of 5 wt%. For example, when the pH of the water mixture (content ratio: 5 wt%) obtained by mixing the inorganic silica porous material with pure water is measured under the condition that the content ratio of the inorganic silica porous material is 5 wt%. PH. The pH of the water mixture can be measured using, for example, a pH meter. In addition, when using the above-described inorganic silica-based porous material with an additive or the like as the adsorbent of the present invention, the above “pH of water mixture obtained by mixing with pure water (content ratio: 5 wt%)” is A water mixture (content ratio: 5 wt%) obtained by mixing inorganic silica based porous material in a state before adhering an additive or the like (that is, no adhering agent or the like) with pure water. Let us say pH.

  In the present specification, the water mixture (content ratio: 5 wt%) can be produced, for example, by the following “method for producing water mixture (content ratio: 5 wt%)”.

Preparation method of water mixture (content ratio: 5 wt%) The above water mixture (content ratio: 5 wt%) is, for example, a sample (“object” for measuring the pH of the water mixture so that the content ratio is 5 wt%. The sample may be referred to as “sample”) and mixed with pure water, stirred sufficiently, and allowed to stand for preparation. Although pure water is used for preparation of the water mixture, a mixed solvent of an organic solvent and pure water may be used. However, when an organic solvent is used, the acid dissociation constant varies greatly depending on the type and concentration of the organic solvent. Therefore, it is generally a water-soluble organic solvent such as alcohol and does not have a large effect on pH. Concentration. The “wt%” has the same meaning as “wt%”. In order to prepare a water mixture having a content ratio of 5 wt%, specifically, for example, 5 g of the target sample is weighed using a scale, and pure water is added to make the whole 100 g, and the liquid is sufficiently mixed. It can be produced by stirring. For example, the inorganic silica-based porous material water mixture (content ratio: 5 wt%) can be produced using the inorganic silica-based porous material as the target sample.

The inorganic silica-based porous material is not particularly limited, but the specific surface area (BET specific surface area) may be 10 m ² / g or more (for example, 10 to 800 m ² / g), preferably 50 m ² / g or more. (For example, 50 to 750 m ² / g), more preferably 100 m ² / g or more (for example, 100 to 700 m ² / g).

The inorganic silica-based porous material is not particularly limited, but the content of SiO ₂ in the porous material may be 5% by weight or more (for example, 5 to 100% by weight), preferably 50% by weight or more. More preferred are inorganic silica-based porous materials that are 65% by weight or more, and more preferably 75% by weight or more.

  The inorganic silica-based porous material is not particularly limited. For example, zeolite (for example, synthetic zeolite, natural zeolite, etc.), silica gel, silica alumina, aluminum silicate, porous glass, diatomaceous earth, hydrous magnesium silicate clay Minerals (for example, talc), allophane, imogolite, acid clay, activated clay, activated bentonite, mesoporous silica, aluminosilicate, fumed silica, fly ash, clinker ash and the like can be mentioned. By using the inorganic silica-based porous material as the adsorbent, the siloxane compound can be removed with high efficiency. Among these, zeolite, diatomaceous earth, silica gel, acidic clay, and activated clay are preferable, and synthetic zeolite, diatomaceous earth, silica gel, acidic clay, and activated clay are more preferable. When zeolite (particularly synthetic zeolite), diatomaceous earth, silica gel, acidic clay, or activated clay is used as the adsorbent, the siloxane compound can be efficiently removed over a longer period of time. In particular, when zeolite (particularly synthetic zeolite) or silica gel is used as the inorganic silica-based porous material, the removal efficiency of both the linear siloxane compound and the cyclic siloxane compound tends to be remarkably excellent. In addition, when silica gel or diatomaceous earth is used as the inorganic silica-based porous material, the siloxane compound tends to be more selectively removed. Only 1 type may be used for the said inorganic silica type porous material, and 2 or more types may be used for it. The synthetic zeolite includes artificial zeolite.

  The zeolite is a porous material having a skeleton mainly composed of silicon element (Si), aluminum element (Al), and oxygen element (O), but a part or all of aluminum element ( Al) may be replaced with a trivalent metal element such as iron element (Fe), boron element (B), gallium element (Ga); or a divalent metal element such as zinc element (Zn). .

  The pore structure of the zeolite is not particularly limited. Although the number of member rings of zeolite is not specifically limited, For example, it is 4-20, Preferably it is 8-20, More preferably, it is 8-12. The number of member rings of zeolite is generally represented by the number of O atoms in the pore ring structure. Moreover, the pore connection (channel system) of zeolite is not particularly limited, but is preferably 1 to 3 dimensions, and more preferably 3 dimensions. In particular, a zeolite (particularly a synthetic zeolite) having a pore structure with 12 member rings and three-dimensional pore connection is preferable.

  Although it does not specifically limit as said synthetic zeolite, For example, A type, ferrierite, MCM-22, ZSM-5, ZSM-11, SAPO-11, mordenite, beta type, X type, Y type, L type, chabazite And synthetic zeolite having a skeletal structure such as offretite. In addition, the said synthetic zeolite may use the zeolite of 1 type of frame structure, and may use it in combination of 2 or more types of zeolite. Moreover, the synthetic zeolite may be prepared in a powder form or may be used in a film form.

  Examples of the artificial zeolite generally include zeolite produced from waste containing silicon and aluminum, such as coal ash discharged from a coal-fired power plant and papermaking sludge incinerated ash discharged from a paper mill. The artificial zeolite may be used alone or in combination of two or more.

  The natural zeolite is not particularly limited, and examples thereof include clinoptilolite (clinoptilolite), mordenite (mordenite), chabazite, natrolite, gonnardite, edding tonite, analsim, leucite, yugawaralite, gismondine, porinite. , Philipsite, Chabazite, Elionite, Haujasite, Ferrierite, Mutinaite, Chernihito, Huerudite, Stillebite, Koureite, Aluminosilicate, Berylsilicate (Rogianite, Shanhalite, etc.), Zinccosilicate (Gaultite) ) And the like. The natural zeolite may be used alone or in combination of two or more.

  The zeolite has a pH of a water mixture (content ratio: 5 wt%) obtained by mixing with pure water of 7 or less (for example, 3 to 7), preferably less than 7 (for example, 3 or more and less than 7), more Preferably it is 3-6.8, More preferably, it is 3.5-6.7, Most preferably, it is 4-6.5. In addition, the water mixture (content ratio: 5 wt%) of zeolite can be prepared using zeolite as a target sample by the above “method for preparing water mixture (content ratio: 5 wt%)”.

The ratio (molar ratio) [SiO ₂ / Al ₂ O ₃ ] of SiO ₂ and Al ₂ O ₃ in the synthetic zeolite is not particularly limited, but may be 4 to 2000 from the viewpoint of the removal efficiency of the siloxane compound. , Preferably 5 to 1500, more preferably 10 to 1000, still more preferably 12 to 600. The above [SiO ₂ / Al ₂ O ₃ ] is considered as an index indicating the hydrophilicity or hydrophobicity of zeolite. When [SiO ₂ / Al ₂ O ₃ ] is high (that is, the silica ratio is high and the alumina ratio is low), the hydrophobicity tends to increase. On the other hand, when [SiO ₂ / Al ₂ O ₃ ] is low (that is, the silica ratio is low and the alumina ratio is high), the hydrophilicity tends to be high. If the hydrophilicity is too high (that is, the hydrophobicity is too low), the surface of the skeleton is covered with water molecules, and it becomes difficult for the hydrophobic siloxane compound to approach the adsorption site (adsorption site). If the hydrophilicity is too low (that is, the hydrophobicity is too high), the acid sites in the zeolite are reduced, and the removal efficiency of the siloxane compound tends to decrease. For this reason, for example, by setting [SiO ₂ / Al ₂ O ₃ ] within the above range, the hydrophilicity or hydrophobicity of the zeolite can be appropriately adjusted, and the removal efficiency of the siloxane compound can be further improved. Among these, when the siloxane compound is a cyclic siloxane compound, the synthetic zeolite preferably has high hydrophobicity, and [SiO ₂ / Al ₂ O ₃ ] is more preferable.

The zeolite is not particularly limited, but may contain a cation in the framework structure. Examples of the cation include, but are not limited to, hydrogen ion (H ⁺ ); ammonium ion (NH ₄ ⁺ ); alkyl-substituted ammonium ion (for example, methylammonium ion ((CH ₃ ) H ₃ N ⁺ )) Dimethylammonium ion ((CH ₃ ) ₂ H ₂ N ⁺ ), trimethylammonium ion ((CH ₃ ) ₃ HN ⁺ ), tetramethylammonium ion ((CH ₃ ) ₄ N ⁺ ), etc.); aryl or aralkyl-substituted ammonium Ions; alkali metal ions such as lithium ion (Li ⁺ ), sodium ion (Na ⁺ ), potassium ion (K ⁺ ); magnesium ion (Mg ²⁺ ), calcium ion (Ca ²⁺ ), barium ion (Ba ²⁺⁾ ) an alkaline earth metal such as ion; zinc ion (Zn ^2+), tin ions (Sn ^2+, Sn ^4+), Ions (Fe ^2+, Fe ^3+), a platinum ion (Pt ^2+), palladium ion (Pd ^2+), titanium ions (Ti ^3+), silver ions (Ag ^+), copper ion (Cu ^+, Cu ^{2 +} ), Manganese ions (Mn ²⁺ , Mn ⁴⁺ ), transition metal ions such as cobalt ions (Co ²⁺ ); gallium ions (Ga ⁺ ) and the like. One kind of the cation may be contained, or two or more kinds may be contained. The content of the cation in the zeolite is not particularly limited. In particular, a zeolite called a proton type zeolite having a high content of hydrogen ions (H ⁺ ) as cations contained in the skeleton structure is preferable.

  The specific surface area (BET specific surface area), average particle diameter (average particle diameter), average pore diameter (diameter), total pore volume, etc. of the zeolite are not particularly limited. Moreover, the said zeolite may use only 1 type and may use 2 or more types.

  As the zeolite, an acid-treated product obtained by acid treatment of natural zeolite or synthetic zeolite, a hydrothermal treatment product obtained by hydrothermal treatment of natural zeolite or synthetic zeolite, an ammonium-treated product obtained by calcining ammonium type zeolite, Proton type zeolite may be used.

  The acid-treated product and the hydrothermally treated product are presumed to be because silanol groups in the zeolite increase due to desorption of cations and aluminum elements in the zeolite by acid in acid treatment or heated steam in hydrothermal treatment. The pH of the water mixture becomes 7 or less, and the removal efficiency of the siloxane compound is increased.

  Examples of the proton type zeolite include, for example, at least a part of cations other than hydrogen ions in natural zeolite or synthetic zeolite (for example, metal ions, ammonium ions, etc.) replaced with hydrogen ions, Examples thereof include synthetic zeolite prepared so as to contain a large amount of hydrogen ions. The proton-type zeolite can also be produced by, for example, a method in which a cation such as sodium ion in natural zeolite or synthetic zeolite is ion-exchanged with ammonium ion and then calcined. In general, a proton type zeolite in which the cation in the zeolite is replaced with a hydrogen ion is called a proton type zeolite. In the above proton type zeolite, at least a part of the cation in the zeolite is replaced with a hydrogen ion. It is not limited to those in which all cations in the zeolite are replaced with hydrogen ions.

  Although proton type zeolite is sometimes used as a catalyst, it is not generally used as an adsorbent. Note that zeolite may be used as an adsorbent, but most of the zeolite used as the adsorbent is basic, that is, the pH of the water mixture exceeds 7. As a specific embodiment in which zeolite is used as an adsorbent, for example, molecular sieve is well known, but the substance removed by molecular sieve is water, which is present in the molecular sieving function of zeolite and in zeolite. It is mainly removed by coordinating water to metal ions such as Na ions. Thus, when utilizing Na ion in zeolite, the pH of the water mixture of zeolite used exceeds 7. Furthermore, examples in which solid acid zeolite is used as an adsorbent are very rare. For example, there is one that removes a basic compound such as ammonia by a neutralization reaction utilizing the acid of the solid acid type zeolite and ion exchange ability. However, the removal target is currently limited to inorganic compounds and basic compounds. That is, there has been no example of using a zeolite whose pH of the water mixture is 7 or less to remove the siloxane compound which is an organic compound.

  The acid clay is not particularly limited, and acid clay produced in various places can be used. Examples include acid clay from Niigata Prefecture and acid clay from Yamagata Prefecture. Only 1 type may be used for the said acid clay, and 2 or more types may be used for it.

  The activated clay is obtained by acid-treating the acid clay. For example, the acid clay is acid-treated with a mineral acid such as sulfuric acid so as not to destroy all of the basic structure of montmorillonite. Examples include those in which a metal oxide such as an oxide is eluted and the specific surface area and pore volume are increased. Only 1 type may be used for the said activated clay, and 2 or more types may be used for it.

  The acidic clay and the activated clay have a pH of a water mixture (content ratio: 5 wt%) obtained by mixing with pure water of 7 or less (for example, 3 to 7), preferably less than 7 (for example, 3 or more). Less than 7), more preferably 3 to 6.5, even more preferably 3.2 to 5, and particularly preferably 3.5 to 4.7. In addition, the acidic white clay water mixture (content ratio: 5 wt%) and the activated white clay water mixture (content ratio: 5 wt%) are either acidic white clay or active according to the above “method for preparing water mixture (content ratio: 5 wt%)”. White clay can be produced as a target sample.

  The diatomaceous earth is not particularly limited, and diatomaceous earth produced in various places can be used. For example, diatomaceous earth (diatom shale) from Wakkanai, Hokkaido, diatomaceous earth from Tsukiko, Akita Prefecture, diatomaceous earth from Ulsan, Okayama Prefecture, diatomaceous earth from Kuju, Oita Prefecture, diatomaceous earth (diatomaceous mudstone) from Noto, Ishikawa Prefecture, etc. May be. Of these, diatomaceous earth produced in Wakkanai, Hokkaido is preferred. Only 1 type may be used for the said diatomaceous earth, and 2 or more types may be used for it.

  The diatomaceous earth has a pH of a water mixture (content ratio: 5 wt%) obtained by mixing with pure water of 7 or less (for example, 3 to 7), preferably less than 7 (for example, 3 or more and less than 7), more Preferably it is 3-6.7, More preferably, it is 3.2-6.5, Most preferably, it is 3.5-6.2. In addition, the water mixture (content rate: 5 wt%) of diatomaceous earth can be produced using diatomaceous earth as a target sample by the above-described “method for producing water mixture (content rate: 5 wt%)”.

  Inorganic silica-based porous materials other than synthetic zeolite, acid clay, activated clay, and diatomaceous earth (sometimes referred to as “other inorganic silica-based porous materials”) are mixed with pure water (content ratio) : 5 wt%) is 7 or less (for example, 3 to 7), preferably less than 7 (for example, 3 or more and less than 7), more preferably 3 to 6.5, and still more preferably 3.5 to 6. 3, particularly preferably 4-6. In addition, the water mixture (content ratio: 5 wt%) of other inorganic silica-based porous materials is the target sample of other inorganic silica-based porous materials according to the above “method for preparing water mixture (content ratio: 5 wt%)”. Can be produced.

In the inorganic silica-based porous material other than the synthetic zeolite, the content of SiO ₂ is not particularly limited, but is 50% by weight or more (for example, 50% by weight based on the total weight (100% by weight) of the inorganic silica-based porous material). ˜100 wt%), preferably 60 wt% or more, more preferably 70 wt% or more.

  Although the said inorganic silica type porous material is not specifically limited, It is preferable that the additive etc. are not attached. That is, it is preferable that the inorganic silica-based porous material to which an additive or the like is added is excluded from the inorganic silica-based porous material. Examples of the additive include an acidic substance additive, a basic substance additive, and an oxidizing agent. For example, when an acidic substance additive is added, the skeleton of the inorganic silica-based porous material may be changed, or the pores may be filled with the acidic substance.

  The adsorbent of the present invention is not particularly limited, but may contain an adsorbent (other adsorbent) other than the inorganic silica-based porous material whose pH of the water mixture is 7 or less, if necessary. That is, as the adsorbent of the present invention, other adsorbents may be used together with the inorganic silica-based porous material whose pH of the water mixture is 7 or less. Examples of the other adsorbent include porous materials other than inorganic silica-based porous materials whose pH of the water mixture is 7 or less, other silicas, clay minerals, activated carbon, alumina, and glass. By using the other adsorbents as the adsorbent, in addition to the effects of the present invention, a chemical filter having the effects of other adsorbents can be obtained.

  The content of the inorganic silica-based porous material in which the pH of the water mixture in the adsorbent of the present invention (in all adsorbents) is 7 or less is not particularly limited, but from the viewpoint of the removal efficiency of the siloxane compound, the adsorbent Is preferably 10% by weight or more (for example, 10 to 100% by weight), more preferably 30% by weight or more, further preferably 50% by weight or more, and particularly preferably 70% by weight. That's it.

  Among the adsorbents of the present invention, zeolite (particularly, synthetic zeolite), diatomaceous earth, silica gel, acidic clay, or activated clay is used as the inorganic silica-based porous material having a water mixture having a pH of 7 or less, and the total weight of the adsorbent. The content is preferably 10% by weight or more (for example, 10 to 100% by weight, preferably 50% by weight or more, more preferably 70% by weight or more) with respect to (100% by weight). When the inorganic silica-based porous material includes two or more of zeolite (particularly synthetic zeolite), diatomaceous earth, silica gel, acidic clay, and activated clay, the content is the total content of the two or more. Amount.

  The chemical filter of this invention will not be specifically limited if the inorganic silica type porous material whose pH of a water mixture (content rate: 5 wt%) is 7 or less is used as an adsorbent. Examples of the chemical filter include a chemical filter in which the adsorbent of the present invention is attached (fixed) to a filter base material. In addition, when the adsorbent of the present invention also has a function as a binder, the adsorbent can be attached to the filter base material without using a binder, but the adsorbent of the present invention uses a binder to filter base. It is preferable that it adheres to the material. That is, the chemical filter may be a chemical filter in which the adsorbent of the present invention is attached to the filter substrate without using a binder (or only the adsorbent of the present invention is attached). A chemical filter in which the adsorbent of the present invention is attached to a filter base material using a binder is preferable.

  The adsorbent of the present invention is not particularly limited, but may be pelletized. That is, the adsorbent of the present invention may be a pelletized adsorbent. That is, the chemical filter of the present invention may contain the pelletized adsorbent of the present invention. The pelletization can be performed, for example, by granulating the adsorbent powder of the present invention using the binder.

(Filter base material)
It does not specifically limit as said filter base material, What is generally used as a filter base material of a chemical filter can be used. Examples of the filter base material include fibrous base materials (woven fabric or non-woven fabric) composed of fibers such as organic fibers and inorganic fibers, foams composed of paper, polyurethane foam, refractory metal oxides, and the like. Examples thereof include a filter base material using a refractory inorganic material (for example, a metal such as aluminum, ceramics, etc.). The shape of the woven fabric of the fibrous base material is not particularly limited, and examples thereof include those in which fibers are woven in a mesh shape. Among these, a fibrous substrate is preferable as the filter substrate.

  Examples of the fiber in the fibrous base material include inorganic fibers such as silica alumina fiber, silica fiber, alumina fiber, mullite fiber, glass fiber, rock wool fiber, and carbon fiber; polyethylene fiber, polypropylene fiber, nylon fiber, and polyester fiber. (For example, polyethylene terephthalate fiber, etc.), polytetrafluoroethylene fiber, polyvinyl alcohol fiber, aramid fiber, pulp fiber, rayon fiber, and other organic fibers. Among these, inorganic fibers are preferable, and glass fibers are more preferable from the viewpoint of increasing the strength of the chemical filter and less contamination due to outgas from the fibers. That is, as the filter substrate, a fibrous substrate (glass cloth (glass cloth)) using glass fibers is preferable. The said fiber may use only 1 type and may use it in combination of 2 or more type. Moreover, the shape of the said inorganic fiber and the said organic fiber is not specifically limited.

(Binder)
The binder can be used for promoting adhesion of the adsorbent to the filter base material or pelletizing the adsorbent. The binder is not particularly limited, and a known or commonly used binder for a filter (for example, for an air filter or a chemical filter) can be used. The binder may be an organic binder or an inorganic binder. The binder is not particularly limited, but is preferably an inorganic binder. The said binder may use only 1 type and may use 2 or more types.

  The binder may be acidic or basic, but is preferably acidic. If the binder is acidic, the removal efficiency of the siloxane compound tends to be higher than when a basic binder is used. The acidic binder has a pH of a water mixture (content ratio: 5 wt%) obtained by mixing with pure water of 7 or less (for example, 3 to 7), preferably less than 7 (for example, 3 or more and less than 7), More preferably, it is 3-6.8, More preferably, it is 3.5-6.7, Most preferably, it is 4-6.5. In addition, the water mixture (content ratio: 5 wt%) of the binder can be manufactured using the binder as a target sample by the above-described “method for manufacturing the water mixture (content ratio: 5 wt%)”. In addition, when the said binder is a binder containing solvents, such as colloidal silica, the said content rate is a content rate of the solid content in the said binder with respect to the said water mixture.

  Examples of the organic binder include polyethylene resins, polypropylene resins, acrylic resins such as methyl methacrylate, ABS resins, polyester resins such as PET, phenol resins, epoxy resins, urethane resins, vinyl acetate resins, and polyvinyl resins. Examples thereof include cellulose such as alcohol and carboxymethylcellulose, and arabic gum. The said organic binder may use only 1 type and may use 2 or more types.

  The inorganic binder is preferably in the form of particles that do not completely cover the surface of the inorganic silica-based porous material. For example, sodium silicate, silica sol, alumina sol, colloidal silica, colloidal alumina, colloidal tin oxide, colloidal Examples thereof include inorganic oxide particles such as titanium oxide. Among them, colloidal inorganic oxide particles such as colloidal silica, colloidal alumina, colloidal tin oxide and colloidal titanium oxide are preferable. Of these, colloidal silica is preferable. The said inorganic binder may use only 1 type and may use 2 or more types.

  The average particle diameter (primary particle diameter), specific surface area (BET specific surface area), average pore diameter (diameter), total pore volume, and the like of the inorganic binder are not particularly limited.

(Chemical filter structure)
The structure of the chemical filter of the present invention is not particularly limited, and examples thereof include a honeycomb structure, a pleat structure, a pellet filling structure, a three-dimensional network structure, and a sheet packaging structure. Among these, a honeycomb structure, a pleated structure, and a three-dimensional network structure are preferable, and a honeycomb structure is particularly preferable from the viewpoint of suppressing pressure loss. When the pelletized adsorbent (pellet) is used as the adsorbent of the present invention, it is not particularly limited, but a pleated structure, a pellet filling structure, or a three-dimensional network structure is preferable. The chemical filter of the present invention may have only one type of structure, or may have a combination of two or more types of structures.

  In addition to the so-called honeycomb structure, the honeycomb structure includes, for example, a lattice shape, a circular shape, a wave shape, a polygonal shape, an indefinite shape, a shape having a curved surface in whole or in part, and a fluid (particularly , Air) includes all structures that can pass through the cells that are the elements of the structure.

  Examples of the honeycomb structure include a structure obtained by alternately laminating corrugated sheets and flat sheets formed by corrugating (corrugated honeycomb structure), and includes a pleated sheet and a flat sheet. Examples of the structure include a structure in which a pleated sheet and a flat sheet are sequentially laminated at right angles to the ventilation direction.

  As the chemical filter of the present invention having a honeycomb structure, for example, a filter base material using a fibrous base material has a corrugated honeycomb structure, and a filter base material using a fibrous base material has a honeycomb structure. Examples thereof include a chemical filter having a honeycomb structure in which a metal filter substrate made of metal such as aluminum has a honeycomb structure.

  The pleated structure includes, for example, a structure having a bellows shape processed so that a waveform or a V shape is continuous in order to efficiently expand a filtration area in a limited space.

  Examples of the pellet filling structure include a structure in which the pelletized adsorbent is filled in a casing having a structure in which a fluid (particularly gas) can pass therethrough. In addition, when the particle size of the adsorbent powder is large enough to be held in the casing, instead of the pellet filling structure, the powder is not pelletized and the powder is filled in the casing. You can also

  The three-dimensional network structure is, for example, a mesh formed by three-dimensionally processing a foam composed of the polyurethane foam or the like, glass fiber (glass wool or the like), rock wool fiber, or fiber of the fibrous base material. A structure having a filter base material of the structure or polytetrafluoroethylene made into needle-like fibers is preferably exemplified.

  Examples of the sheet packaging structure include a structure in which an air-permeable sheet such as a non-woven fabric or PTFE is molded into a bag of any size and filled with an adsorbent. Further, the particle size of the adsorbent may be pelletized so that the adsorbent particles do not leak out of the sheet, but depending on the sheet, it can be used as a powder.

(Method for producing chemical filter of the present invention)
The manufacturing method of the chemical filter of this invention is not specifically limited, The manufacturing method of the chemical filter which has a well-known thru | or usual adsorption agent can be used. Although the chemical filter of this invention is not specifically limited, For example, it has at least the process (adsorbent adhesion process) which makes the adsorbent of this invention adhere to a filter base material. Although the manufacturing method of the chemical filter of this invention is not specifically limited, You may have processes (other processes) other than the said adsorption agent adhesion process. Moreover, the said filter base material may purchase a commercially available filter base material, and may use it as it is.

  In the adsorbent adhering step, the adsorbent of the present invention is adhered to, for example, the filter substrate, the adsorbent of the present invention, a solvent (for example, water), and a suspension containing the binder as necessary. After dipping in, it can be carried out by removing from the suspension and drying. The suspension may contain an antisettling agent as long as the effects of the present invention are not impaired.

  In addition, the adsorbent of the present invention is attached to the filter base material after being immersed in a suspension containing the solvent and, if necessary, the binder, then taken out from the suspension, dried, and then filtered. It can also be carried out by dispersing and adsorbing the adsorbent of the present invention on the substrate surface.

  In addition, the adsorbent of the present invention is attached to the filter base material (particularly, non-woven fabric) by spraying the mixed solution containing the adsorbent of the present invention, the solvent, and, if necessary, the binder. It can also be performed by applying and adhering.

  In addition, the adsorbent of the present invention can be attached to the above filter base material by adhering pellets produced by granulating the adsorbent powder of the present invention with an adhesive or filling the inside of the filter base material. It can also be done. When granulating the adsorbent powder of the present invention, the binder may be mixed as necessary. When the adsorbent powder of the present invention, the binder, and the solvent (preferably water) are mixed in an appropriate amount, the clay-like viscosity and plasticity are exhibited, and granulation becomes possible.

  In addition, the adsorbent of the present invention can be attached by using a polytetrafluoroethylene resin that has been made into acicular fibers and capturing and adsorbing the adsorbent of the present invention on the acicular fibers.

  In addition, the adsorbent of the present invention may be attached in a state where the adsorbent of the present invention is contained in nanofibers. As said nanofiber, well-known thru | or usual nanofiber can be used. Moreover, the said nanofiber can also be produced with the manufacturing method of well-known thru | or a usual nanofiber. Examples of the method for producing the nanofiber include an electrospinning (ES) method (electrospinning, electrostatic spinning), a melt blow method, a composite melt spinning method, and the like. In the ES method, a high voltage is applied to a suspension in which the adsorbent of the present invention is dispersed in a polymer solution, and the suspension is sprayed on a ground surface (for example, a filter substrate (for example, a non-woven fabric) having a zero surface potential). Do. In the ES method, when the suspension is sprayed at a high voltage, nanofibers containing the adsorbent of the present invention are formed.

  In the case of a chemical filter using a filter base material (for example, a metal filter base material) to which the adsorbent is difficult to adhere, the adsorbent of the present invention is attached to the filter base material using an adhesive. You may go.

  In the pleated structure chemical filter, the adsorbent of the present invention is adhered to, for example, by adhering the adsorbent powder or pelletized adsorbent of the present invention between two non-woven filter substrates. It can also be performed by sandwiching with an agent or the like.

  As said other process, the process (filter base material processing process) etc. which process a filter base material are mentioned, for example. The order of the filter base material processing step and the adsorbent attachment step is not particularly limited, but the order of the filter base material processing step and the adsorbent attachment step is preferable from the viewpoint of workability.

  Examples of the filter base material processing step include a step of corrugating the filter base material, a step of forming a honeycomb structure, and a step of providing pores in the filter base material as described above. The said filter base-material process process may perform only 1 process, and may perform the same or different 2 or more processes. Also when performing the said filter base-material process process 2 steps or more, the order is not specifically limited.

  The chemical filter of the present invention may be a chemical filter manufactured by a papermaking method. The chemical filter manufactured by the papermaking method is, for example, a chemical filter having at least a fibrous base material and the adsorbent of the present invention, and contains the fibers constituting the fibrous base material and the adsorbent of the present invention. A substance (floc) produced by adding a flocculant to the suspension is formed into a sheet by a wet papermaking method and then heat-treated.

  The chemical filter of the present invention may be a ceramic type chemical filter. The ceramic-type chemical filter can be produced by a known or common processing method for ceramic materials. For example, the adsorbent of the present invention can be produced by molding and firing together with a ceramic raw material. Specifically, for example, after preparing the clay by weighing and kneading the adsorbent of the present invention, the binder, the pore former, and other ceramic raw materials as required, the clay is extruded by screw type extrusion. Extrusion is performed by an extruder such as a machine to produce a molded body. The obtained molded body is dried and fired to obtain a porous ceramic type chemical filter. The ceramic type chemical filter is not particularly limited, but a ceramic type chemical filter having a honeycomb structure is preferable. The ceramic-type chemical filter can be processed into a predetermined length by a grinding tool such as a diamond cutter or a diamond saw as appropriate.

  Among the above, the chemical filter of the present invention is particularly preferably a chemical filter having a honeycomb structure in which a plurality of corrugated sheets each having the adsorbent of the present invention attached to its surface with an inorganic binder are laminated via thin sheet sheets.

  Although not particularly limited, it is preferable that the chemical filter of the present invention does not include an adsorbent to which an additive (for example, an acidic substance, a basic substance, an oxidizing agent, or the like) is attached. That is, the chemical filter of the present invention is preferably excluded from those having an adsorbent to which an additive is attached.

  The chemical filter of the present invention uses an inorganic silica-based porous material whose pH of the water mixture is 7 or less as an adsorbent. Thereby, in the chemical filter of the present invention, since the silanol group (-Si-OH) exists in the inorganic silica porous material that acts as a solid acid, the siloxane compound is hydrolyzed by the solid acid, and the compound is converted into silanol. It is assumed that a group is formed. As a result, the silanol group (—Si—OH) in the inorganic silica porous material and the silanol group generated by hydrolysis of the siloxane compound in the fluid (particularly in the air) are dehydrated and condensed. The Si-O-Si bond is formed and presumed to be mainly due to chemical adsorption, but it seems that the siloxane compound is strongly adsorbed and removed, and the once adsorbed siloxane compound becomes difficult to desorb. Yes. In addition, the bond between the inorganic silica-based porous material and the adsorbed siloxane compound is significantly stronger than the case where activated carbon is used.

  As described above, the chemical filter of the present invention removes the siloxane compound by using an inorganic silica-based porous material having a water mixture having a pH of 7 or less as an adsorbent. For this reason, unlike the case of using an adsorbent such as activated carbon, the siloxane compound once adsorbed is not desorbed because it is firmly bonded. Therefore, the adsorption capacity is easier to estimate than the chemical filter using activated carbon as the adsorbent, and the life analysis is relatively easy. Further, as will be described later, since it is difficult to desorb even when the pressure is returned from high pressure to normal pressure, it is useful to dispose the chemical filter of the present invention in a pressure pipe in the siloxane compound removal equipment of the present invention.

  Patent Documents 2 to 5 disclose that a cyclic siloxane compound is removed using a resin or a porous material into which an acidic functional group is introduced. However, the sulfonic acid as the acidic functional group is a protonic acid, and the property is completely different from the solid acid in the inorganic silica-based porous material such as zeolite. The same applies to the removal of the siloxane compound. In the said patent documents 2-5, the said acidic functional group has a role which makes siloxane compounds react. On the other hand, in the present invention, as described above, it is adsorbed by dehydration condensation between the silanol group (—Si—OH) in the inorganic silica-based porous material and the silanol group generated by hydrolysis of the siloxane compound. I guess that. As described above, the adsorption mechanism is completely different between the porous material into which the acidic functional group is introduced and the adsorbent of the present invention. And when the siloxane compound removal equipment of the present invention having the chemical filter of the present invention is used, since the reaction between the siloxane compounds is not necessary, the environment is such that the concentration of the siloxane compound in the fluid is extremely low. Also, the siloxane compound can be removed efficiently.

  Moreover, in the said patent documents 2-5, resin or porous material into which the acidic functional group was introduce | transduced is used. For this reason, in patent documents 2-5, the process of introduce | transducing an acidic functional group becomes essential when producing a chemical filter. In particular, the process for producing an acidic compound used in Patent Documents 3 and 4 is extremely complicated. On the other hand, it is not necessary to use a resin or a porous material into which an acidic functional group is introduced as the adsorbent of the present invention. For this reason, the chemical filter of this invention does not need to provide the process of attaching an acidic compound to resin or a porous material, the process of manufacturing an acidic compound, etc., and can be produced easily. Therefore, the siloxane compound removal equipment of the present invention can be easily produced.

  Furthermore, in the chemical filter using activated carbon as the adsorbent, when other gas components such as an organic gas component are present in addition to the siloxane compound in the fluid, the removal of the siloxane compound is competitive with the removal of the organic gas component. For this reason, the removal efficiency of a siloxane compound falls. In contrast, the adsorbent of the present invention is presumed to remove the siloxane compound mainly by the silanol group in the inorganic silica-based porous material as described above, but it is in competition with the removal of the organic gas component. In other words, the siloxane compound tends to be selectively and efficiently removed.

[Chemical filter for removing inhibitory substances]
The inhibitor removing chemical filter is a chemical filter for removing an inhibitor that lowers the siloxane compound removing ability of the chemical filter of the present invention. The inhibitor removing chemical filter is installed upstream of the chemical filter of the present invention.

  The chemical filter for removing the inhibitory substance is not particularly limited as long as it is a chemical filter that removes a substance (inhibitor substance) that reduces the siloxane compound removing ability of the chemical filter of the present invention. Examples of such chemical filters for removing inhibitory substances include basic substances removing chemical filters that adsorb basic substances such as ammonia and amines; acidic substances such as hydrogen sulfide, sulfur oxides, nitrogen oxides, and organic acids. Chemical filters for removing acidic substances that adsorb organic substances; Chemical filters for removing organic substances that adsorb organic substances such as benzene, toluene, and cyclohexanone; Chemical filters for removing silanol compounds that adsorb silanol compounds. As the chemical filter for removing the inhibitory substance, a chemical filter for removing a basic substance and a chemical filter for removing a silanol compound are particularly preferable. If the chemical filter for removing an inhibitory substance is a chemical filter for removing a basic substance, the basicity may reduce the acidic point of the inorganic silica porous material in the adsorbent of the present invention in the chemical filter of the present invention. It is preferable because the substance can be efficiently removed and the chemical filter of the present invention can be maintained for a long time without deteriorating the ability to remove the siloxane compound. Further, when the inhibitor removing chemical filter is a silanol compound removing chemical filter, a silanol compound that reduces silanol groups of the inorganic silica-based porous material in the adsorbent of the present invention in the chemical filter of the present invention is efficiently used. The chemical filter of the present invention is preferable because it can be maintained for a long time without deteriorating the ability to remove the siloxane compound.

The silanol compound is a compound having at least a silanol group (—Si—OH) as represented by R _4-n Si (OH) _n . N is preferably an integer of 1 to 3. R represents a hydrogen atom; a halogen atom such as a fluorine atom or a chlorine atom; an optionally substituted hydrocarbon group (preferably an alkyl group, more preferably an alkyl group having 1 to 3 carbon atoms), and the like. It is done. When there are a plurality of Rs, two or more of the plurality of Rs may be the same or different. The silanol compound is preferably volatile. As the silanol compound, trimethylsilanol (TMS) is particularly preferable.

  The chemical filter for removing the inhibitory substance may be any chemical filter that removes the inhibitory substance, and the material and shape of the chemical filter for removing the inhibitory substance are not particularly limited.

  For example, when the chemical filter for removing an inhibitory substance has an adsorbent or an ion exchange resin, the adsorbent or the ion exchange resin is not particularly limited, and can be appropriately selected depending on the kind of the inhibitor to be removed. Examples of the adsorbent and ion exchange resin include adsorbents (for example, activated carbon) and ion exchange resins that are used in known or conventional chemical filters. Further, the adsorbent may be non-added, and basic substances such as potassium hydroxide, sodium hydroxide and potassium carbonate; acidic substances such as phosphoric acid, sulfuric acid, sulfate, nitric acid and nitrate are attached. It may be. The inhibitor removing chemical filter is not limited to the one having the adsorbent or the ion exchange resin, and includes, for example, a filter base material having an ion exchange function (for example, a nonwoven fabric having an ion exchange function). The chemical filter used may be used.

  As the adsorbent in the chemical filter for removing the inhibitory substance, specifically, when the inhibitory substance is a basic substance, an adsorbent to which an acidic substance is attached (particularly, activated carbon to which an acidic substance is attached) When the inhibitor is an acidic substance, an adsorbent to which a basic substance is attached (particularly, activated carbon to which a basic substance is attached) is used. In the case where the inhibitory substance is a silanol compound, adsorbents with no addition or with an acidic substance (particularly, activated carbon with an acidic substance or no addition of activated carbon) are preferred. Note that the non-adsorbing adsorbent may have an adsorbing agent added to such an extent that removal of the organic substance or silanol compound is not significantly inhibited.

  The structure of the inhibitor removing chemical filter is not particularly limited, and examples thereof include those illustrated and described as the structure of the chemical filter of the present invention.

[Siloxane Compound Removal Equipment of the Present Invention]
The siloxane compound removal equipment of the present invention has the chemical filter of the present invention. In the chemical filter of the present invention, the presence of the surface of the inorganic silica-based porous material having a pH of 7 or less in the water mixture in the chemical filter allows the siloxane compound to be hydrolyzed by the inorganic silica-based porous material that acts as a solid acid. It is estimated that the siloxane compound can be effectively removed by decomposing and dehydrating and condensing with many silanol groups present in the inorganic silica porous material to form a siloxane bond and adsorbing the siloxane compound firmly. The Even when another adsorbent is used in combination as the adsorbent, the surface of the inorganic silica-based porous material having a pH of the water mixture of 7 or less exists in the chemical filter. The effect that it can be removed can be maintained. For this reason, the siloxane compound removal equipment of the present invention having the chemical filter of the present invention can efficiently remove the siloxane compound.

  Furthermore, the siloxane compound removal equipment of the present invention has the inhibitor removing chemical filter upstream of the chemical filter of the present invention. In the chemical filter of the present invention, the siloxane compound removing ability may be lowered depending on the substance to be adsorbed. For this reason, the siloxane compound removal system of the present invention has a chemical filter that removes a substance (inhibitor substance) that lowers the siloxane compound removal ability upstream of the chemical filter of the present invention, so that the inhibitor substance removes the inhibitor substance. By being removed by the chemical filter for use, the inhibitor can reduce the siloxane compound removing ability of the chemical filter of the present invention and can be maintained for a long time.

  The siloxane compound removal facility of the present invention is not particularly limited, but may have a chemical filter (other chemical filter) other than the chemical filter of the present invention and the above-described inhibitor removal chemical filter. In this case, the siloxane compound removing equipment of the present invention may have the chemical filter of the present invention next to the chemical filter for removing the inhibitor, or the chemical filter for removing the inhibitor and the chemical filter of the present invention. You may have the said other chemical filter in between.

  The siloxane compound removal equipment of the present invention may have only one chemical filter or inhibitor removal chemical filter of the present invention, or may have two or more. Further, when two or more chemical filters for removing an inhibitory substance are included, the two or more chemical filters for removing an inhibitory substance may remove the same inhibitory substance or remove different inhibitory substances. Also good. Further, when two or more inhibitory substance removal chemical filters are provided, it is only necessary that at least one inhibitory substance removal chemical filter is located upstream of the chemical filter of the present invention.

  In the siloxane compound removal facility of the present invention, the position of the inhibitor removing chemical filter may be upstream of the chemical filter of the present invention. That is, the siloxane compound removal equipment of the present invention has a structure in which a fluid (particularly air) containing a siloxane compound passes through the chemical filter of the present invention after passing through the chemical filter for removing an inhibitory substance. That's fine. Therefore, in the siloxane compound removal facility of the present invention, each chemical filter (the chemical filter of the present invention, the chemical filter for removing an inhibitory substance, etc.) may be partially or entirely disposed separately, All may be arranged continuously (for example, stacked). In the case where a part or all of them are arranged separately, the separation interval is not particularly limited. As an example in which a part or the whole is continuously arranged, for example, a chemical filter (a panel type filter, a cell type filter, a chemical filter for piping, which will be described later) a part or all of the chemical filter is collectively framed. Etc.). As an example in which a part or all of the chemical filters are arranged separately, for example, a chemical filter in which some or all of the chemical filters are respectively framed, and each of the framed chemical filters has one long flow. For example, a device that is arranged on the road in isolation. The inhibitor removing chemical filter may be installed immediately before the chemical filter of the present invention, or upstream of the chemical filter of the present invention in a passage through which a fluid (particularly air) containing the siloxane compound passes. In addition, it may be installed away from the chemical filter of the present invention.

  As a method of using the siloxane compound removal equipment of the present invention, for example, using a power such as a ventilation fan, the substance to be removed is introduced into the inside of the apparatus equipped with the chemical filter for removing the inhibitor and the chemical filter of the present invention in this order. In addition to the aeration method that forcibly introduces air containing air and removes the substance to be removed, air is used to power the inside of the apparatus equipped with the chemical filter for removing the inhibitory substance and the chemical filter of the present invention in this order. Rather than introducing the method, there is a stationary method in which the substance to be removed is removed by contact only with natural diffusion or natural convection. That is, the siloxane compound removal equipment of the present invention can be used in either the ventilation method or the stationary method. As the siloxane compound removal equipment using the ventilation method, for example, a ventilation fan (for example, a device for taking in air or a device for discharging air), the chemical filter of the present invention, and the chemical filter for removing an inhibitory substance are integrated. A unit (sometimes referred to as a “fan filter unit (FFU)”). The FFU can be attached to a ceiling or a clean booth, or provided in the middle of a duct.

  In the siloxane compound removal equipment of the present invention, each chemical filter (the chemical filter of the present invention, the chemical filter for removing an inhibitory substance, etc.) is a chemical filter (framed chemical filter) in a framed state. Also good. Moreover, the chemical filter in which all the chemical filters in the siloxane compound removal equipment of the present invention are framed may be used, or a chemical filter in which some chemical filters are framed may be used. Further, it may be framed for each chemical filter, or a part or all of the chemical filters may be collectively framed.

  The framed chemical filter is obtained, for example, by putting a chemical filter (filter medium) in which an adsorbent is attached to a filter base material. Examples of the framed chemical filter include a panel type filter, a cell type filter, a piping chemical filter, and the like. In addition, both the said filter medium and the said framed chemical filter correspond to the chemical filter in this specification.

  Examples of the panel type filter include a chemical filter in which the edge of a plate-shaped filter medium is fitted in a frame like a frame. The panel type filter is generally used so that a fluid containing a siloxane compound is allowed to pass in the thickness direction of a plate-shaped filter medium. The shape of the frame is not particularly limited and can be appropriately selected depending on the usage mode. Examples of the shape of the frame include a polygonal shape (for example, a triangular shape, a quadrangular shape, a hexagonal shape, a frame shape, etc.), a circular shape, an elliptical shape, a shape in which some or all of the corners of the polygon are rounded, The shape etc. which combined these shapes are mentioned. Further, the plate-shaped filter medium may be a single sheet, or may be a stack of a plurality of filter mediums.

  Examples of the cell type filter include a filter in which a filtering medium is arranged inside a cell having a hexahedral shape (cube, rectangular parallelepiped, etc.) so that a fluid containing a siloxane compound passes through the filtering medium. Examples of the cell-type filter include a chemical filter in which the filter medium has a series of bent portions so that the filter medium has a continuous V shape, and the bent portions are arranged to face the aeration direction. The cell type filter may be a chemical filter arranged in a folding screen so that each of the bent portions is cut, that is, a plurality of filter media have a V-shaped structure. In the cell type filter in which the filter medium is arranged to have a V-shaped structure, the fluid containing the siloxane compound is arranged to pass in the thickness direction of the filter medium arranged to have the V-shaped structure.

  Examples of the pipe chemical filter include a chemical filter in which a filter medium is packed in a part of a pipe (for example, a cylinder, a square cylinder, etc.). In the portion where the filter medium is packed, it is preferable that the filter medium is packed over the entire cross-section of the tubular pipe so that all the fluid containing the siloxane compound passes through the filter medium. The chemical filter for piping can be preferably used in pressure piping.

  In the siloxane compound removal equipment of the present invention, when each chemical filter is disposed separately, the environment in which each chemical filter is installed may be the same or different.

(Usage environment of the siloxane compound removal equipment of the present invention)
The siloxane compound removal equipment of the present invention can be used in various environments where chemical filters can be used. For example, the chemical filter of the present invention can be used in a high-temperature environment where activated carbon cannot be used, or in an environment such as various concentration environments and humidity environments. The chemical filter can be used in these environments.

  The chemical filter of the present invention can be used in a wide temperature environment (for example, an environment of 0 to 500 ° C.). A chemical filter using activated carbon as an adsorbent cannot be used because the activated carbon gradually oxidizes in a high-temperature environment, the activation progresses and the pores widen, and the removal performance decreases. In addition, an adsorbent using an organic substance such as a resin cannot be used in a high temperature environment because the resin melts or ignites in a high temperature environment or progresses in an environment exceeding 40 ° C. On the other hand, since the chemical filter of the present invention in the siloxane compound removal facility of the present invention does not necessarily use activated carbon as an adsorbent, it can be used in a wide temperature environment including a high temperature environment. Although the temperature of the environment where the chemical filter of this invention is used in the siloxane compound removal equipment of this invention is not specifically limited, 10-300 degreeC is preferable, More preferably, it is 15-100 degreeC, More preferably, it is 15-50 degreeC. is there.

  In addition, chemical filters using activated carbon as an adsorbent are thought to activate the molecular motion of the siloxane compound in a high-temperature environment by removing the siloxane compound by physical adsorption. Tends to decrease. On the other hand, since the adsorbent of the present invention is considered to remove the siloxane compound with a strong bond mainly as in chemical adsorption, the siloxane compound can be efficiently removed even in a high temperature environment.

The chemical filter of the present invention can be used in a wide range of humidity environments (for example, in an environment with a relative humidity of 0 to 99% RH) as long as no condensation occurs. For this reason, in the siloxane compound removal equipment of the present invention, the chemical filter of the present invention can also efficiently remove siloxane compounds in dry air or purge gas with an inert gas such as N ₂ gas. The relative humidity at which the chemical filter of the present invention is used in the siloxane compound removal equipment of the present invention is not particularly limited, but is preferably 0 to 95% RH, more preferably 0 to 60% RH, and still more preferably 0 to 40%. RH.

  When a zeolite having a pH of 7 or less is used as the inorganic silica-based porous material having a pH of 7 or less in the water mixture, the amount of hydrogen ions in the zeolite is large and the amount of other cations is relatively small. Because of its relatively high hydrophobicity, it is difficult to adsorb moisture in the fluid even in a high humidity environment, and is less susceptible to humidity. For this reason, the siloxane compound can be efficiently removed even in a high humidity environment.

The chemical filter of the present invention can be used under a wide pressure environment (for example, an environment of 10 ^{−11 to} 100 MPa). The chemical filter using activated carbon as the adsorbent increases the removal efficiency because the concentration of the substance to be removed increases under a high-pressure environment. There is a tendency to detach. On the other hand, the chemical filter of the present invention strongly adsorbs and removes the siloxane compound, and therefore does not desorb when used under a high pressure environment and then returned to normal pressure. For this reason, the chemical filter of the present invention can be used in a wide pressure environment including a high pressure environment in the siloxane compound removal facility of the present invention. Although the pressure of the environment where the chemical filter of this invention is used is not specifically limited, 10 < ^-7 > -1MPa is preferable, More preferably, it is 10 < ^-4 > -1MPa, More preferably, it is 0.05-1MPa. For this reason, the chemical filter of this invention can be preferably used also in pressure piping in the siloxane compound removal equipment of this invention. In addition, you may have the chemical filter of this invention and the chemical filter for inhibitory substance removal in one pressure piping.

  The chemical filter of the present invention can be preferably used even in a wide range of siloxane compound concentration environments (for example, 0.001 ppb to 10 ppm). In addition, the chemical filter of the present invention can remove the siloxane compound with high efficiency even in an environment where the concentration of the siloxane compound in the fluid is extremely low (for example, 1 digit ppb or less). In particular, the siloxane compound removal equipment of the present invention (particularly the chemical filter of the present invention) has a concentration of the siloxane compound in the fluid (particularly in the air) of 100 ppb or less (preferably 50 ppb or less, more preferably 10 ppb or less). It can be preferably used in an extremely low concentration environment. Although not particularly limited, the concentration of the siloxane compound in the fluid is preferably 0.001 ppb or more.

  In addition, when using the siloxane compound removal equipment of the present invention (particularly, the chemical filter of the present invention) in an environment where the concentration of the siloxane compound in the fluid is extremely low, the temperature of the environment is not particularly limited, but is 0 to 500. ° C is preferred, more preferably 15 to 50 ° C.

  The chemical filter of the present invention can be used under various wind speed environments (for example, the filtration wind speed is 0 to 5 m / s). In particular, it can be used even in a high wind speed environment (for example, in an environment where the filtration wind speed is 1 to 5 m / s). A chemical filter using activated carbon as an adsorbent tends to have lower removal efficiency as the wind speed of the passing air is higher. On the other hand, the chemical filter of the present invention can efficiently remove the siloxane compound even under a high wind speed environment. Although the wind speed of the environment in which the chemical filter of the present invention is used in the siloxane compound removal facility of the present invention is not particularly limited, the filtration wind speed is preferably 0 to 5 m / s, more preferably the filtration wind speed is 0 to 3 m / s, More preferably, the filtration wind speed is 0 to 1 m / s.

  Moreover, the siloxane compound removal equipment of the present invention (particularly, the chemical filter of the present invention) is used in an environment where the content of gas other than the siloxane compound is low (low gas environment) and in an environment where the concentration of air is low (for example, vacuum It can be used even in the environment). In addition, since the chemical filter of the present invention does not necessarily use activated carbon as an adsorbent, the chemical filter of the present invention is preferably used in an environment where flame retardancy is required in the siloxane compound removal facility of the present invention. it can.

  The siloxane compound removal equipment of the present invention is equipment for removing a siloxane compound. The siloxane compound is a compound having at least a Si—O—Si skeleton in the molecule. Examples of the siloxane compound include cyclic siloxane compounds (for example, D3-D20 cyclic siloxane compounds such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, etc.), linear siloxane compounds (for example, Straight chain siloxane compounds having 2 to 20 silicon atoms such as hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, etc.), branched siloxane compounds, and the like. Among these, a cyclic siloxane compound and a linear siloxane compound are preferable. The siloxane compound is preferably volatile.

[Fluid purification method]
Furthermore, the fluid can be purified by removing the siloxane compound in the fluid using the siloxane compound removal equipment of the present invention. As described above, the method for removing the siloxane compound in the fluid using the siloxane compound removing equipment of the present invention and purifying the fluid may be referred to as “the fluid purification method of the present invention”. For this reason, the siloxane compound removal equipment of the present invention can be installed at an appropriate place in order to remove the siloxane compound in the fluid (for example, in the air). For example, the siloxane compound removal equipment of the present invention includes equipment in buildings such as ordinary households and clean rooms, equipment in magnetic disk storage devices (for example, equipment in HDDs), equipment in construction sites, equipment in sewage treatment plants, It can be particularly preferably used as an application where removal of the siloxane compound is required, such as a facility in a landfill. As equipment in the clean room, equipment around the semiconductor manufacturing process, such as equipment inside the exposure apparatus, equipment inside the coating and developing apparatus, equipment around the semiconductor chip cutting process, equipment around the liquid crystal display manufacturing process, etc. are particularly preferable. .

  In the clean room (for example, a clean room in which gaseous pollutants are controlled, particularly a clean room in a semiconductor manufacturing factory), various gaseous organic compounds such as siloxane compounds exist. Siloxane compounds may be adsorbed on the surface of a semiconductor silicon wafer or the surface of a liquid crystal glass substrate, causing problems in these products. In the above sewage treatment plant, the digestion gas generated from the digester contains a trace amount of siloxane compounds resulting from silicone oil contained in shampoos and cosmetics. Furthermore, in the above landfill, siloxane compounds and silanol compounds contained in biogas in mud (active sludge and the like) used for landfill may be problematic. Therefore, the siloxane compound removal equipment of the present invention can be particularly preferably used for fluid (particularly air) purification for such applications.

  Moreover, it can be preferably used also for applications that require avoidance of poisoning by siloxane compounds such as gas sensors and reaction catalysts. In addition, it can also be used in the vicinity of various analyzers, gas supply lines, the periphery where cell regeneration processing is performed, the periphery where micropore processing is performed, a nuclear power plant, and the like. In addition, since the siloxane compound may reduce the electromotive force of the fuel cell, it can be preferably used in the manufacturing process of the fuel cell. Furthermore, siloxane compounds can accumulate in gas turbines, boiler burners, heat exchangers, etc., reducing efficiency and causing malfunctions and failures, so they can also be used in such locations. .

  When the siloxane compound removal equipment of the present invention can selectively remove the siloxane compound (for example, when the chemical filter for removing the inhibitor does not remove the gas to be detected by the gas sensor), the siloxane compound removal equipment of the present invention Of these, the use for gas sensor is particularly preferable. In general households, gas sensors are used as sensors (detectors) for detecting propane and butane. In such a gas sensor, it is known that when a siloxane compound adheres to the surface of the detection unit, the sensitivity of the sensor is lowered and the detection capability is affected. In order to protect the sensor from the siloxane compound, a filter for adsorbing the siloxane compound is attached to the gas sensor. In general, activated carbon is used as an adsorbent in the filter. However, a filter using such an adsorbent adsorbs even a gas that needs to be detected by a gas sensor such as propane or butane. Therefore, the gas sensor may be difficult to operate. On the other hand, the chemical filter of the present invention in the siloxane compound removal facility of the present invention can selectively remove the siloxane compound with high efficiency. For this reason, it is especially preferable that the siloxane compound removal equipment of the present invention is used as a gas sensor application (preferably an application installed on the upstream side of the detector in the gas sensor).

  When the siloxane compound removal facility of the present invention is a facility for gas sensor application, the siloxane compound removal facility of the present invention can be used in places where gas sensors can be used, such as ordinary households, canteens, kitchens, propane, butane, etc. It can be used where hydrocarbon gas may be present. More specifically, it is preferable that the siloxane compound removal equipment of the present invention is provided and used immediately before the gas detection part of the gas sensor. In addition, there is a stationary method in which the siloxane compound removal equipment of the present invention is installed in the space where the gas sensor is installed, and the siloxane compound to be removed is removed by contact with only natural diffusion or natural convection.

[Gas sensor]
The siloxane compound removal equipment of the present invention can be used as a gas sensor by being used inside the gas sensor. The gas sensor provided with the siloxane compound removal equipment of the present invention may be referred to as “the gas sensor of the present invention”. The gas sensor of the present invention includes the siloxane compound removal facility of the present invention having the chemical filter of the present invention inside. In particular, in the gas sensor of the present invention, the siloxane compound removal equipment of the present invention is preferably provided immediately before the gas detection unit. According to the gas sensor of the present invention, as the internal chemical filter in the siloxane compound removal equipment of the present invention, the chemical filter of the present invention using an inorganic silica-based porous material whose pH of the water mixture is 7 or less as an adsorbent is used. Therefore, the siloxane compound in the air can be efficiently removed as compared with a gas sensor using a conventional chemical filter for gas sensor using activated carbon as an adsorbent. In particular, the removal efficiency of the siloxane compound does not decrease in a short time, and the siloxane compound is not desorbed like activated carbon. For this reason, the fall of the gas detection function of the gas sensor resulting from the siloxane compound in air can be suppressed notably. In addition, the adsorptivity of hydrocarbon gas such as propane and butane is low and does not hinder the operation of the gas sensor. Furthermore, since the siloxane compound is not desorbed from the adsorbent and the sensitivity of the sensor in the gas sensor is not lowered, sensor failure due to the siloxane compound in the air can be remarkably suppressed.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to them. “Ppb” is based on weight unless otherwise specified.

  In addition, the VOC used in the following Examples 1 to 5 does not contain an inhibitor that reduces the ability of the test sample to remove the siloxane compound. That is, Examples 1 to 5 below are based on the assumption that an inhibitor removal chemical filter is provided upstream of the siloxane compound removal chemical filter.

Example 1
The gas removal efficiency of the adsorbent was measured using an aeration test apparatus as shown in FIG. In Example 1, two series of acrylic cylindrical test columns (inner diameter: 50 mm, length: 30 cm) 1 connected in series are arranged in parallel in six lines, and a gas supply tube 2 is arranged upstream of the column. The flow meter 3, the flow rate adjusting valve 4, and the pump 5 were attached in this order on the downstream side of the column. The nonwoven fabric 6 was sandwiched between two columns connected in series, a test sample (adsorbent) 7 was laid on the nonwoven fabric 6 with a thickness of 5 mm, and the flow rate was adjusted so that the filtration wind speed of the test sample was 5 cm / s. Air was blown. The air flowing through the column was mixed with 200 ppb of octamethylcyclotetrasiloxane (D4) in air adjusted to a temperature of 23 ° C. and a humidity of 50% using a constant temperature and humidity chamber. A schematic cross-sectional view (for one series) of the aeration test apparatus is shown in FIG.
As a test sample (adsorbent), a plurality of zeolites having different pHs in the water mixture (content ratio: 5 wt%) shown in Table 1, and a plurality of water mixtures (content ratio: 5 wt%) shown in Table 2 having different pH values. Silica gel, acid clay, activated clay and diatomaceous earth were used. The removal efficiency was measured for every six test samples, and each of the six test samples to be measured was used for each column 1 arranged in parallel in six series. Natural zeolite B is a citric acid-treated product of natural zeolite A.
On the third day after the start of the aeration test, air on the upstream and downstream sides of the column is collected by an adsorption tube, and the adsorption tube that collects the air is subjected to gas analysis by ATD (heat desorption device) -GC / MS. The gas concentration of D4 was measured. The removal efficiency of D4 was calculated from the measured D4 gas concentration on the upstream side and downstream side of the column by the following formula, and a graph of the relationship between the pH of the water mixture of the test sample and the removal efficiency was created.
Removal efficiency (%) = {(Upstream gas concentration−Downstream gas concentration) / Upstream gas concentration} × 100
The results are shown in Table 1, Table 2, FIG. 3 (zeolite), and FIG. 4 (silica gel, acid clay, activated clay, diatomaceous earth). In FIG. 4, square marks (□) indicate silica gel data, triangle marks (Δ) indicate acid clay data, circle marks (◯) indicate active clay data, and cross marks (×) diatomaceous earth data. The horizontal axis of the graph is the pH of the water mixture of the test sample, and the vertical axis is the removal efficiency (%).

  As shown in Table 1, Table 2, FIG. 3, and FIG. 4, inorganic silica-based porous materials such as zeolite, silica gel, activated clay, diatomaceous earth and the like whose water mixture has a pH of 7 or less have a pH of the water mixture of 7 The removal efficiency of D4 is remarkably large as compared with an inorganic silica-based porous material exceeding 50.

Comparative Example 1
As in the case of Example 1 except that an acidic ion exchange resin (containing a sulfonic acid group) was used as a test sample (adsorbent), gas removal of the adsorbent was performed using a ventilation test apparatus as shown in FIG. Efficiency was measured.
On the third day after the start of the aeration test, air on the upstream and downstream sides of the column is collected by an adsorption tube, and the adsorption tube that collects the air is subjected to gas analysis by ATD (heat desorption device) -GC / MS. The gas concentration of D4 was measured. The removal efficiency of D4 was calculated by the following formula from the measured D4 gas concentration on the upstream side and downstream side of the column.
Removal efficiency (%) = {(Upstream gas concentration−Downstream gas concentration) / Upstream gas concentration} × 100
As a result, the removal efficiency of D4 when using an acidic ion exchange resin was 0%.

Example 2
An extraction test with acetone was performed on some test samples after the completion of the aeration test of Example 1. Some of the above test samples were placed in 30 ml acetone solvent and shaken for 2 hours. Thereafter, the supernatant was subjected to GC-FID analysis. Table 3 shows area values measured by GC-FID of D4. For comparison, coconut shell activated carbon (manufactured by Phutamura Chemical Co., Ltd., trade name “Taiko CB”, pH of water mixture: 10.17), and acid impregnated activated carbon (potassium hydrogen sulfate was impregnated with the coconut shell activated carbon). The amount of the additive added to the activated carbon is 6% by weight, the pH of the water mixture is 2.61, and the chemical activated carbon (Futamura Chemical Co., Ltd., trade name “Dazai S”). The pH of the water mixture is 4.48. ) Was used as an adsorbent, and the same air permeability test as in Example 1 was performed. Then, the area values measured by GC-FID of D4 are shown in Table 3 in the same manner as the above test sample. In addition, the area value shown in Table 3 is a numerical value when the area value of the coconut shell activated carbon is 100 (volume conversion).

  As shown in Table 3, in the case of coconut shell activated carbon, acid-impregnated activated carbon, and chemical activated activated carbon, adsorbed D4 is desorbed by acetone extraction, but the water mixture has a pH of 7 or less, zeolite, silica gel, activated clay. In the case of an inorganic silica-based porous material such as diatomaceous earth, the adsorbed D4 is not desorbed by acetone extraction. From this, it can be seen that D4 is adsorbed to an inorganic porous silica-based material whose pH of the water mixture is 7 or less with an extremely strong force as compared with activated carbon.

Example 3
Gel permeation chromatography analysis was performed on each of some test samples (synthetic zeolite D, synthetic zeolite I, silica gel B, activated clay A, and diatomaceous earth A) after completion of the aeration test of Example 1. 0.5 g of the above test sample and 1 g of tetrahydrofuran (THF) were mixed and eluted, filtered, and the molecular weight was measured by gel permeation chromatography. That is, a molecular weight measuring device (CO-8020 UV-8020 RI-9202 DP-8020, manufactured by Tosoh Corporation) is equipped with a column with a filler (showdex KE-806M 804 802, Showa Denko Corporation), The eluent was THF (THF without a stabilizer, manufactured by Wako Pure Chemical Industries, Ltd.), and measurement was performed at a column temperature of 40 ° C. at 1.0 mL / min. As a result, a peak having a weight average molecular weight of several hundreds was detected, but a larger peak having a weight average molecular weight of several hundred thousand was not detected.
From this result, the adsorbent of the present invention does not polymerize and adsorb the siloxane compound as in the inventions described in Patent Documents 2 and 5, but directly reacts the inorganic silica porous material with the siloxane compound. You can see that it has been removed.

Example 4
As the air flowing through the column, in the same manner as in Example 1, except that air adjusted to a temperature of 23 ° C. and a humidity of 50% using a constant temperature and humidity chamber was mixed with 60 ppb decamethyltetrasiloxane. 1 was used to measure the gas removal efficiency of the adsorbent. In addition, the several zeolite and diatomaceous earth from which pH of the water mixture (content rate: 5 wt%) shown in Table 4 differs were used as a test sample (adsorbent).
On the third day after the start of the aeration test, air on the upstream and downstream sides of the column is collected by an adsorption tube, and the adsorption tube that collects the air is subjected to gas analysis by ATD (heat desorption device) -GC / MS. The gas concentration of decamethyltetrasiloxane was measured. The removal efficiency of decamethyltetrasiloxane was calculated from the gas concentration of decamethyltetrasiloxane on the upstream side and downstream side of the measured column by the following formula, and a graph of the relationship between the pH of the water mixture of the test sample and the removal efficiency was created.
Removal efficiency (%) = {(Upstream gas concentration−Downstream gas concentration) / Upstream gas concentration} × 100
The results are shown in Table 4 and FIG. In FIG. 5, rhombuses (◇) indicate zeolite data, and crosses (×) indicate diatomaceous earth data. The horizontal axis of the graph is the pH of the water mixture of the test sample, and the vertical axis is the removal efficiency (%).

  As shown in Table 4 and FIG. 5, the inorganic silica-based porous material such as zeolite or diatomaceous earth whose pH of the water mixture is 7 or less is higher than the inorganic silica-based porous material whose pH of the water mixture exceeds 7. The removal efficiency of decamethyltetrasiloxane is remarkably large.

Example 5
The air flowed through the column was the same as in Example 1 except that air adjusted to a temperature of 23 ° C. and a humidity of 50% using a constant temperature and humidity chamber was mixed with 100 ppb of n-hexane and 100 ppb of toluene. The gas removal efficiency of the adsorbent was measured using an aeration test apparatus as shown in FIG. In addition, the some inorganic silica type porous material from which pH of the activated carbon and water mixture (content rate: 5 wt%) shown in Table 5 differs was used as a test sample (adsorbent).
On the third day after the start of the aeration test, air on the upstream and downstream sides of the column is collected by an adsorption tube, and the adsorption tube that collects the air is subjected to gas analysis by ATD (heat desorption device) -GC / MS. The gas concentrations of n-hexane and toluene were measured. The removal efficiency of each gas component was calculated from the measured gas concentrations of n-hexane and toluene on the upstream side and downstream side of the column by the following formula, and a graph of the relationship between the pH of the water mixture of the test sample and the removal efficiency was created. .
Removal efficiency (%) = {(Upstream gas concentration−Downstream gas concentration) / Upstream gas concentration} × 100
The results are shown in Table 5.

  As shown in Table 5, when an inorganic silica-based porous material having a pH of the water mixture of 7 or less is used, the removal efficiency of organic compounds such as n-hexane and toluene is relatively low. For this reason, a siloxane compound can be selectively removed.

Example 6
(Production example of ammonia-treated product of synthetic zeolite)
Using an aeration test apparatus as shown in FIG. 1, an ammonia-treated product of synthetic zeolite was produced. That is, two acrylic cylindrical test columns (inner diameter 50 mm, length 30 cm) 1 connected in series are arranged in 6 series in parallel, and a gas supply tube 2 is attached to the upstream side of the column, On the downstream side of the column, a flow meter 3, a flow rate adjustment valve 4, and a pump 5 were attached in this order. A nonwoven fabric 6 is sandwiched between two columns connected in series, and zeolite for performing ammonia treatment is placed on the nonwoven fabric 6 in place of the test sample 7 in a thickness of 2.5 mm (bulk volume: 4.8 mL). The air containing ammonia gas was flowed so that the flow rate was adjusted to 3.0 cm / s.
Synthetic zeolite L (pH of water mixture: 5.25, skeleton structure: mordenite, specific surface area: 450 m ² , [SiO ₂ / Al ₂ O ₃ ]: 240), the above-mentioned synthetic zeolite G, The synthetic zeolite C and the synthetic zeolite M (pH of water mixture: 4.52, framework structure: beta type, specific surface area: 400 m ² , [SiO ₂ / Al ₂ O ₃ ]: 500) were used. Four synthetic zeolites to be treated with ammonia were respectively used in four columns 1 among six columns arranged in parallel.
Air containing ammonia gas on the upstream side and downstream side of each column was collected, and the concentration of ammonia gas was measured. The concentration of upstream ammonia gas was 5.5 ppm. After 12 hours from the start of aeration of air containing ammonia gas, it was confirmed that the concentration of ammonia gas on the downstream side of each column was 5.5 ppm, which was the same as that on the upstream side, so the ammonia treatment to each synthetic zeolite was completed. As a result, the ventilation of air containing ammonia gas was terminated. In this way, an ammonia-treated product of synthetic zeolite was produced. In addition, the density | concentration of ammonia gas was measured using 3 L of detection tubes by Gastec Corporation.

(D4 ventilation test)
A 4.8 mL test sample (adsorbent) 7 is laid on the non-woven fabric 6 in a thickness of 2.5 mm, and air that is adjusted to a temperature of 23 ° C. and a humidity of 50% using a thermostatic chamber is used as D4. As shown in FIG. 1, in the same manner as in Example 1, except that 30 ppb was used and air whose flow rate was adjusted so that the filtration wind speed of the test sample was 3.0 cm / s was passed. The gas removal efficiency of the adsorbent was measured using an aeration test apparatus.
As test samples (adsorbents), synthetic zeolite L, synthetic zeolite G, synthetic zeolite C, synthetic zeolite M, ammonia-treated product of synthetic zeolite L, ammonia-treated product of synthetic zeolite G, synthetic zeolite C shown in Table 6 And the above-mentioned ammonia-treated product of synthetic zeolite M were used. The weights of the test samples were 1.9 g of synthetic zeolite L and its ammonia-treated product, 2.0 g of synthetic zeolite G and its ammonia-treated product, 1.9 g of synthetic zeolite C and its ammonia-treated product, and synthetic zeolite M, respectively. And its ammonia-treated product was 3.2 g. In addition, when an ammonia-treated product of synthetic zeolite is used as a test sample, a siloxane compound removal facility that does not have an inhibitor removal filter is used (that is, the basic substance ammonia, which is an inhibitor, is used to remove the inhibitor). It is assumed that the filter is not removed.
The upstream and downstream air of the column was collected by an adsorption tube, and the adsorption tube which collected the air was subjected to gas analysis by ATD (heat desorption device) -GC / MS, and the gas concentration of D4 was measured. The removal efficiency of D4 was calculated from the measured D4 gas concentration on the upstream side and downstream side of the column by the following formula, and a graph of the time change of the test sample was created.
Removal efficiency (%) = {(Upstream gas concentration−Downstream gas concentration) / Upstream gas concentration} × 100
The results are shown in Table 6 and FIG. In FIG. 6, circles (◯) indicate data for synthetic zeolite L, triangles (Δ) indicate data for synthetic zeolite G, diamonds (◇) indicate data for synthetic zeolite C, and squares (□) indicate data for synthetic zeolite M. Data are shown respectively. In addition, white indicates an untreated product, and black indicates an ammonia-treated product. In FIG. 6, the horizontal axis of the graph represents elapsed days (days) and the vertical axis represents removal efficiency (%).

  For measurement of the GC / MS, a product name “JMS-Q1000GC MKII” manufactured by JEOL Ltd. was used.

  As shown in Table 6 and FIG. 6, when a synthetic zeolite whose pH of the water mixture is 7 or less is used and the synthetic zeolite is not attached with ammonia which is a basic gas, the pH of the water mixture is 7 or less. Compared with the case where the synthetic zeolite is treated with ammonia, the removal efficiency of D4 is remarkably large even if the number of days elapses. That is, in the case of having an inhibitor removal chemical filter upstream of a siloxane compound removal chemical filter using synthetic zeolite whose pH of the water mixture is 7 or less as an adsorbent, when no inhibitor removal chemical filter is provided. In comparison, it is clear that the removal efficiency of D4 is remarkably large even after days.

Example 7
(Production example of ammonia-treated product of silica gel, activated clay, diatomaceous earth)
Using an aeration test apparatus as shown in FIG. 1, ammonia-treated products of silica gel, activated clay, and diatomaceous earth were prepared. That is, two acrylic cylindrical test columns (inner diameter 50 mm, length 30 cm) 1 connected in series are arranged in 6 series in parallel, and a gas supply tube 2 is attached to the upstream side of the column, On the downstream side of the column, a flow meter 3, a flow rate adjustment valve 4, and a pump 5 were attached in this order. A nonwoven fabric 6 is sandwiched between two columns connected in series, and an inorganic silica-based porous material for carrying out ammonia treatment instead of the test sample 7 on the nonwoven fabric 6 is 2.5 mm thick (bulk volume: 4.8 mL). ), And air containing ammonia gas was flowed so that the flow rate of the inorganic silica-based porous material was adjusted to 3.0 cm / s.
Silica gel B, activated clay A, and diatomaceous earth A shown in Table 2 were used as the inorganic silica-based porous material for the ammonia treatment. Three inorganic silica-based porous materials to be treated with ammonia were respectively used for three columns 1 out of six columns arranged in parallel.
Air containing ammonia gas on the upstream side and downstream side of each column was collected, and the concentration of ammonia gas was measured. The concentration of upstream ammonia gas was 5.5 ppm. After 12 hours from the start of aeration of air containing ammonia gas, it was confirmed that the concentration of ammonia gas on the downstream side of each column was 5.5 ppm, the same as that on the upstream side, so ammonia to each inorganic silica-based porous material Judging that the treatment was completed, the ventilation of air containing ammonia gas was terminated. In this way, an ammonia-treated product of silica gel, an ammonia-treated product of activated clay, and an ammonia-treated product of diatomaceous earth were produced. In addition, the density | concentration of ammonia gas was measured using 3 L of detection tubes by Gastec Corporation.

(D4 ventilation test)
A 4.8 mL test sample (adsorbent) 7 is laid on the non-woven fabric 6 in a thickness of 2.5 mm, and air that is adjusted to a temperature of 23 ° C. and a humidity of 50% using a thermostatic chamber is used as D4. As shown in FIG. 1, in the same manner as in Example 1, except that 30 ppb was used and air whose flow rate was adjusted so that the filtration wind speed of the test sample was 3.0 cm / s was passed. The gas removal efficiency of the adsorbent was measured using an aeration test apparatus.
As a test sample (adsorbent), silica gel B, activated clay A, diatomaceous earth A, ammonia-treated product of silica gel B, ammonia-treated product of active clay A, and ammonia-treated product of diatomaceous earth A shown in Table 2 were used. . The weights of the test samples were 0.7 g for silica gel B and its ammonia-treated product, 3.9 g for activated clay A and its ammonia-treated product, and 3.0 g for diatomaceous earth A and its ammonia-treated product, respectively. In addition, when an ammonia-treated product of an inorganic silica-based porous material is used as a test sample, a siloxane compound removal facility that does not have an inhibitor removal filter is used (that is, the basic gas ammonia as an inhibitor is removed). It is assumed that the substance is not removed by the inhibitor removal filter.
The upstream and downstream air of the column was collected by an adsorption tube, and the adsorption tube which collected the air was subjected to gas analysis by ATD (heat desorption device) -GC / MS, and the gas concentration of D4 was measured. The removal efficiency of D4 was calculated from the measured D4 gas concentration on the upstream side and downstream side of the column by the following formula, and a graph of the time change of the test sample was created.
Removal efficiency (%) = {(Upstream gas concentration−Downstream gas concentration) / Upstream gas concentration} × 100
The results are shown in Table 7 and FIG. In FIG. 7, circles (◯) indicate data for silica gel B, triangles (Δ) indicate data for activated clay A, and squares (□) indicate data for diatomaceous earth A. In addition, white indicates an untreated product, and black indicates an ammonia-treated product. In FIG. 7, the horizontal axis of the graph represents elapsed days (days), and the vertical axis represents removal efficiency (%).

  As shown in Table 7 and FIG. 7, silica gel, activated clay, and diatomaceous earth whose pH of the water mixture is 7 or less are used, and these inorganic silica-based porous materials do not attach ammonia, which is a basic gas. In this case, the removal efficiency of D4 is remarkably large even when the number of days elapses, compared with the case where the silica gel, activated clay, and diatomaceous earth whose pH of the water mixture is 7 or less are treated with ammonia. That is, when a chemical filter for removing an inhibitory substance is provided upstream of a chemical filter for removing a siloxane compound using silica gel, activated clay, and diatomaceous earth having a pH of 7 or less as an adsorbent, the inhibitory substance removing chemical filter It is clear that the removal efficiency of D4 is remarkably large even if the number of days elapses, compared with the case where there is no.

Example 8
(Example of production of TMS-treated synthetic zeolite)
A TMS-treated product of synthetic zeolite was prepared using an aeration test apparatus as shown in FIG. That is, two acrylic cylindrical test columns (inner diameter 50 mm, length 30 cm) 1 connected in series are arranged in 6 series in parallel, and a gas supply tube 2 is attached to the upstream side of the column, On the downstream side of the column, a flow meter 3, a flow rate adjustment valve 4, and a pump 5 were attached in this order. A nonwoven fabric 6 is sandwiched between two columns connected in series, and zeolite for performing ammonia treatment is placed on the nonwoven fabric 6 in place of the test sample 7 in a thickness of 2.5 mm (bulk volume: 4.8 mL). The air containing TMS gas was flowed with the flow rate adjusted to be 3.0 cm / s.
As the zeolite to be subjected to the TMS treatment, the synthetic zeolite L, the synthetic zeolite G, the synthetic zeolite C, and the synthetic zeolite M were used. Four synthetic zeolites to be subjected to TMS treatment were respectively used for four columns 1 of six columns arranged in parallel.
Air containing TMS gas on the upstream side and downstream side of each column was collected, and the concentration of TMS gas was measured. The concentration of the upstream TMS gas was 5.0 ppm. 12 hours after the start of aeration of air containing TMS gas, it was confirmed that the concentration of TMS gas on the downstream side of each column was 5.0 ppm, which was the same as that on the upstream side, so that the TMS treatment for each synthetic zeolite was completed. As a result, the ventilation of the air containing TMS gas was terminated. In this way, a TMS-treated product of synthetic zeolite was produced. In addition, the density | concentration of TMS gas was measured using GC-FID.

(D4 ventilation test)
A 4.8 mL test sample (adsorbent) 7 is laid on the non-woven fabric 6 in a thickness of 2.5 mm, and air that is adjusted to a temperature of 23 ° C. and a humidity of 50% using a thermostatic chamber is used as D4. As shown in FIG. 1, in the same manner as in Example 1, except that 30 ppb was used and air whose flow rate was adjusted so that the filtration wind speed of the test sample was 3.0 cm / s was passed. The gas removal efficiency of the adsorbent was measured using an aeration test apparatus.
As test samples (adsorbents), synthetic zeolite L, synthetic zeolite G, synthetic zeolite C, synthetic zeolite M, TMS-treated product of synthetic zeolite L, TMS-treated product of synthetic zeolite G, synthetic zeolite C shown in Table 8 The TMS-treated product of the above and the TMS-treated product of the above synthetic zeolite M were used. The weights of the test samples were 1.9 g of synthetic zeolite L and its TMS-treated product, 2.0 g of synthetic zeolite G and its TMS-treated product, 1.9 g of synthetic zeolite C and its TMS-treated product, and synthetic zeolite M, respectively. And the TMS processed product was 3.2 g. In addition, when a TMS-treated product of synthetic zeolite is used as a test sample, when a siloxane compound removal facility that does not have an inhibitor removal filter is used (that is, the TMS of the silanol compound, which is an inhibitor, is removed) Is assumed to be removed).
The upstream and downstream air of the column was collected by an adsorption tube, and the adsorption tube which collected the air was subjected to gas analysis by ATD (heat desorption device) -GC / MS, and the gas concentration of D4 was measured. The removal efficiency of D4 was calculated from the measured D4 gas concentration on the upstream side and downstream side of the column by the following formula, and a graph of the time change of the test sample was created.
Removal efficiency (%) = {(Upstream gas concentration−Downstream gas concentration) / Upstream gas concentration} × 100
The results are shown in Table 8 and FIG. In FIG. 8, circles (◯) indicate data for synthetic zeolite L, triangles (Δ) indicate data for synthetic zeolite G, diamonds (◇) indicate data for synthetic zeolite C, and squares (□) indicate data for synthetic zeolite M. Data are shown respectively. In addition, white indicates an unprocessed object, and black indicates a TMS processed object. In FIG. 8, the horizontal axis of the graph is the elapsed days (days), and the vertical axis is the removal efficiency (%).

  For measurement of the GC / MS, a product name “JMS-Q1000GC MKII” manufactured by JEOL Ltd. was used.

  As shown in Table 8 and FIG. 8, when a synthetic zeolite having a pH of 7 or less in the water mixture is used and the synthetic zeolite does not adhere TMS which is a silanol compound, the pH of the water mixture is 7 or less. Compared with the case where a certain synthetic zeolite is treated with TMS, the removal efficiency of D4 is large even if the number of days elapses. That is, in the case of having an inhibitor removal chemical filter upstream of a siloxane compound removal chemical filter using synthetic zeolite whose pH of the water mixture is 7 or less as an adsorbent, when no inhibitor removal chemical filter is provided. In comparison, it is clear that the removal efficiency of D4 is large even after days.

1 Column 2 Tube 3 Flowmeter 4 Flow Control Valve 5 Pump 6 Nonwoven Fabric 7 Test Sample (Adsorbent)

Claims (7)

  A siloxane compound removing chemical filter using an inorganic silica-based porous material having a pH of 7 or less as a water mixture (content ratio: 5 wt%) obtained by mixing with pure water as an adsorbent, and the siloxane compound removing chemical A siloxane compound removal facility, comprising an inhibitor removal chemical filter installed upstream of a filter for removing an inhibitor that reduces the siloxane compound removal ability of the siloxane compound removal chemical filter.   The siloxane compound removing equipment according to claim 1, wherein the inhibitor removing chemical filter is at least one selected from the group consisting of a basic substance removing chemical filter and a silanol compound removing chemical filter.   The inorganic silica-based porous material is zeolite, silica gel, silica alumina, aluminum silicate, porous glass, diatomaceous earth, hydrous magnesium silicate clay mineral, allophane, imogolite, acidic clay, activated clay, activated bentonite, mesoporous silica, The siloxane compound removal equipment according to claim 1 or 2, which is at least one inorganic silica-based porous material selected from the group consisting of aluminosilicate, fumed silica, fly ash, and clinker ash.   4. The adsorbent according to claim 1, wherein another adsorbent is used together with the inorganic silica-based porous material having a pH of 7 or less as the water mixture (content ratio: 5 wt%) as the adsorbent. Siloxane compound removal equipment.   As the inorganic silica-based porous material, at least one selected from the group consisting of synthetic zeolite, diatomaceous earth, silica gel, acid clay, and activated clay whose pH of the water mixture (content ratio: 5 wt%) is 7 or less. The siloxane compound removal equipment according to any one of claims 1 to 4, comprising 10% by weight or more based on the total weight of the adsorbent.   The inorganic silica-based porous material includes a synthetic zeolite having a water mixture (content ratio: 5 wt%) having a pH of 7 or less, and the synthetic zeolite is A-type, ferrierite, MCM-22, ZSM-5, ZSM- 11. A synthetic zeolite having at least one skeleton structure selected from the group consisting of 11, SAPO-11, mordenite, beta type, X type, Y type, L type, chabazite, and offretite. The siloxane compound removal equipment according to any one of the above.   A fluid purification method, wherein the siloxane compound is removed by using the siloxane compound removal equipment according to any one of claims 1 to 6.

Images