Adsorption column for collecting acid or base components in gas and its use

Abstract

A collection adsorption column is provided that can quantify acid or base components in a gas in a short time with high sensitivity. [Solution] An adsorption column for capturing acidic or basic components in gas is used, which is filled with a non-porous substrate that holds a basic adsorbent for adsorbing acidic components or an acidic adsorbent for adsorbing basic components, and which has a pressure loss of 10 kPa or less when the gas inside is sucked at a suction rate of 2.0 L / min.

Description

[Technical Field]

[0001] The present invention relates to an adsorption column for collecting acid or base components in gas and uses thereof, specifically to a method for collecting acid or base components in gas, a method for quantifying the concentration of acid or base components in gas using the collection method, and a method for controlling the cleanliness of a clean room using the quantification method. [Background technology]

[0002] In environments where electronic substrates (hereinafter referred to as substrates), such as semiconductor wafers, liquid crystal substrates, and magnetic disks, are manufactured, contaminants, such as acidic substances (acidic components) and basic substances (basic components), in the manufacturing space can adsorb onto the substrates, resulting in reduced product yield and quality. To prevent this, the manufacturing process of such substrates is carried out in a clean room. It is necessary to evaluate the contamination level of the clean room caused by the acidic substances, basic substances, etc., during each manufacturing process, i.e., the cleanliness level, and to manage the cleanliness of the clean room by, for example, removing the cause of contamination if the cleanliness level deteriorates. Furthermore, in recent years, clean rooms have been required to ensure highly clean spaces. Accordingly, there has been a demand for methods for evaluating the contamination level of acidic or basic components, i.e., the cleanliness level, with higher sensitivity. Furthermore, in recent years, there has been a demand for shortening the time required for the evaluation in order to simplify clean room cleanliness management.

[0003] Examples of methods for evaluating the cleanliness level with high sensitivity and in a short time include a method for quantifying contaminants using a gas adsorption column described in Patent Documents 1 and 2, or a liquid-free trap described in Patent Document 3. Here, the contaminants refer to acidic and / or basic components in the air. Specifically, the method for quantifying contaminants involves passing air in a clean room through the gas adsorption column or liquid-free trap to adsorb the contaminants in the air, and then quantifying the amount of the adsorbed contaminants. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-14522 [Patent Document 2] International Publication No. 2010 / 067464 [Patent Document 3] Patent No. 6563396 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the evaluation methods using gas adsorption columns described in Patent Documents 1 and 2 leave room for improvement in terms of the time required for evaluation. Also, the evaluation method using a liquid-free trap described in Patent Document 3 leaves room for improvement in terms of sensitivity.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a collection adsorption column that can be used to quantify acid or base components in gases in a short time with high sensitivity, and a method for collecting and quantifying the acid or base components. Another object of the present invention is to provide a method for managing the cleanliness of a space, which can easily ensure a highly clean space. [Means for solving the problem]

[0007] In order to achieve the above object, an adsorption column for collection according to one embodiment of the present invention is an adsorption column for collection of acid components or base components in a gas, The non-porous substrate is filled, the non-porous substrate holds a basic adsorbent for adsorbing an acid component or an acidic adsorbent for adsorbing a base component; the pressure loss when the gas in the collection adsorption column is sucked through the collection adsorption column at a suction rate of 2.0 L / min is 10 kPa or less; This is an adsorption column for collecting acid or base components in gas.

[0008] In order to achieve the above object, a method for capturing an acid component or a base component in a gas is provided, which comprises passing the gas through an adsorption column for capture according to an embodiment of the present invention, and capturing the acid component or the base component in the gas.

[0009] Furthermore, in order to achieve the above object, a quantitative determination method according to one embodiment of the present invention includes a collection step of collecting an acid component or a base component in the gas using a collection method according to one embodiment of the present invention; an elution step of passing a solvent through the adsorption column in which the acid component or the base component has been collected, thereby eluting the collected acid component or the base component into the solvent to obtain an eluate; and The method for quantifying the concentration of an acid component or a base component in a gas includes a measuring step of measuring the concentration of the acid component or the base component in the eluate.

[0010] In addition, in order to achieve the other object, a management method according to one embodiment of the present invention includes a quantification step of quantifying the concentration of an acid component or a base component in a gas in a space using a quantification method according to one embodiment of the present invention; This is a method for managing the cleanliness of a space, which includes a step of identifying and eliminating a source of the acid component or base component in the gas inside the space when the concentration of the acid component or base component quantified in the quantification step exceeds a threshold value. [Effects of the Invention]

[0011] The adsorption column for collection according to one embodiment of the present invention, the collection method according to one embodiment of the present invention, and the quantification method according to one embodiment of the present invention enable the quantification of acid or base components in gas in a short time with high sensitivity. Furthermore, the method for managing the cleanliness of a space according to one embodiment of the present invention allows a highly clean space to be easily ensured. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a quantitative measurement device used in Examples 4 and 5. DETAILED DESCRIPTION OF THE INVENTION

[0013] Although one embodiment of the present invention will be described below, the present invention is not limited to the following embodiments. Various modifications of the present invention are possible within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0014] [Embodiment 1: Collection adsorption column] A collection adsorption column according to one embodiment of the present invention (hereinafter also referred to as "the collection adsorption column") is an adsorption column for collecting acidic or basic components in gas, which is packed with a non-porous substrate, and which holds a basic adsorbent for adsorbing acidic components or an acidic adsorbent for adsorbing basic components. The non-porous substrate holds a basic adsorbent for adsorbing acidic components or an acidic adsorbent for adsorbing basic components, and the pressure loss when gas is drawn into the collection adsorption column at a suction rate of 2.0 L / min through the collection adsorption column is 10 kPa or less.

[0015] Hereinafter, this adsorption column packed with a non-porous substrate carrying a basic adsorbent is also referred to as an "acid component adsorption column" because it is a column for collecting acid components in gas. Hereinafter, this adsorption column packed with a non-porous substrate carrying an acidic adsorbent is also referred to as a "base component adsorption column" because it is a column for collecting base components in gas. This adsorption column is either an acid component adsorption column or a base component adsorption column.

[0016] (Non-porous base material) The collection adsorption column is packed with a non-porous substrate, and the non-porous substrate holds a basic adsorbent for adsorbing acidic components or an acidic adsorbent for adsorbing basic components.

[0017] Generally, porous materials have been used as constituent materials of the adsorbent packed into a collection adsorption column, due to their large surface area and the ability to easily capture the target substance. However, when quantifying a substance adsorbed in a collection adsorption column, the adsorbed substance is desorbed and eluted in a solvent to prepare an eluate, which is then used for quantification. Adsorbent components made of porous materials have a strong adsorption ability for the target substance, making it difficult to desorb the substance into the solvent when adsorbing extremely small amounts of the substance. Therefore, it is believed that quantitative determination methods using collection adsorption columns packed with adsorbent components made of porous materials cannot quantify extremely small amounts of the substance.

[0018] Furthermore, the adsorbent composed of a porous material may also incorporate substances other than the substance to be adsorbed. Therefore, in a quantitative determination method using a collection adsorption column filled with an adsorbent composed of a porous material, substances other than the substance to be adsorbed, i.e., substances other than the substance to be quantified, are trapped inside the adsorption column. As a result, the presence of these other substances becomes noise, making it impossible to quantify extremely small amounts of the substance.

[0019] On the other hand, the non-porous substrate has a weaker adsorption force for the substance to be adsorbed than the porous material, and even when adsorbing a very small amount of substance, the adsorbed substance can be easily desorbed into the solvent. Therefore, the quantitative determination method using this adsorption column for collection can quantify very small amounts of substance.

[0020] In addition, the present adsorption column is packed with a non-porous substrate, and the other substances are not incorporated into the non-porous substrate. This prevents the presence of the other substances from making it impossible to quantify trace amounts of the substance. Here, in one embodiment of the present invention, the substance to be quantified is an acid component or a base component in a gas.

[0021] As described above, the present adsorption column for collection can collect and quantify acid or base components in gas with high sensitivity. In this specification, collection and quantification with high sensitivity means, for example, measuring the concentration of acid or base components in gas at a level of about 10 -2 μg / m 3 This means that the amount of the collected and quantified particles is on the order of 100 ppm.

[0022] The non-porous substrate may be made of any material, as long as it has no pores. Examples of the material for the non-porous substrate include quartz, glass, polycarbonate resin, polystyrene resin, polyamide resin, silicon carbide (SiC), alumina (Al2O3), and silicon nitride (SiN). From the viewpoint of effectively preventing contamination of the non-porous substrate during use of the adsorption column, the material for the non-porous substrate is preferably quartz or glass, and particularly preferably quartz.

[0023] The shape of the non-porous substrate is not particularly limited, but from the viewpoint of the adsorption column for collection of acid or base components in gas, a shape with a large surface area is preferred. Examples of shapes with a large surface area include a particulate shape and a fibrous shape. The shape of the non-porous substrate is more preferably a particulate shape.

[0024] The lower limit of the average particle size or average cross-sectional diameter of the non-porous substrate is preferably 300 μm or more, more preferably 400 μm or more, even more preferably 450 μm or more, even more preferably 500 μm or more, and particularly preferably 600 μm or more, from the viewpoint of increasing the efficiency of aeration to the adsorption column. The upper limit of the average particle size or average cross-sectional diameter of the non-porous substrate is preferably 1200 μm or less, more preferably 1100 μm or less, even more preferably 1050 μm or less, even more preferably 1000 μm or less, and particularly preferably 850 μm or less, from the viewpoint of increasing the efficiency of capturing the acid component or the base component to the adsorption column. The method for measuring the average particle size and average cross-sectional diameter is in accordance with JIS K0069 "Sieving Test Method for Chemical Products."

[0025] The basic adsorbent is an adsorbent for adsorbing acid components, and specifically may be made of or contain a basic substance, while the acidic adsorbent is an adsorbent for adsorbing base components, and specifically may be made of or contain an acidic substance.

[0026] In one embodiment of the present invention, the acid component is not particularly limited. Examples of the acid component include acids such as hydrogen chloride, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, formic acid, acetic acid, bromic acid, iodine, lactic acid, propionic acid, butyric acid, and valeric acid, as well as ammonium fluoride, ammonium formate, and ammonium acetate. In addition, in one embodiment of the present invention, the base component is not particularly limited. Examples of the base component include bases such as ammonia, trimethylamine, triethylamine, alkanolamine, dimethylamine, and diethylamine, as well as ammonium fluoride, ammonium formate, and ammonium acetate.

[0027] The amount of the basic adsorbent or acidic adsorbent in the adsorption column is preferably 0.4 μeq or more, more preferably 0.7 μeq or more, and even more preferably 0.8 μeq or more. Adjusting the amount of the basic adsorbent or acidic adsorbent to 0.4 μeq or more is preferable in terms of preventing breakthrough of the column when collecting high-concentration gases. On the other hand, the amount of the basic adsorbent or acidic adsorbent is preferably 50 μeq or less, more preferably 30 μeq or less, and even more preferably 20 μeq or less. Adjusting the amount of the basic adsorbent or acidic adsorbent to 50 μeq or less is preferable in terms of preventing measurement interference due to excess adsorbent components. The amount of the basic adsorbent or acidic adsorbent is a value expressed in equivalents and can be measured by the method described in the Examples.

[0028] The basic adsorbent may be an inorganic base or an organic base. The inorganic base may be an alkali metal carbonate or an alkali metal hydroxide. The organic base may be an amine or an ammonium compound.

[0029] Of the compounds listed above, the basic adsorbent is preferably at least one compound selected from the group consisting of alkali metal carbonates, alkali metal hydroxides, amines, and ammonium compounds.

[0030] Examples of the alkali metal carbonates include sodium carbonate, potassium carbonate, and potassium hydrogen carbonate. Examples of the alkali metal hydroxides include strontium hydroxide, potassium hydroxide, and sodium hydroxide. Examples of the amines include triethanolamine. Examples of the ammonium compounds include tetramethylammonium hydroxide and tetrabutylammonium hydroxide.

[0031] The basic adsorbent is more preferably at least one compound selected from the group consisting of sodium carbonate, sodium hydroxide, and triethanolamine.

[0032] The acidic adsorbent may include inorganic acids and organic acids.

[0033] Examples of the inorganic acid include sulfuric acid, phosphoric acid, etc. Examples of the organic acid include methanesulfonic acid, maleic acid, malonic acid, etc.

[0034] Of the compounds listed above, the acidic adsorbent is preferably at least one compound selected from the group consisting of sulfuric acid, phosphoric acid, and methanesulfonic acid.

[0035] In one embodiment of the present invention, the form in which the non-porous substrate holds the basic adsorbent or the acidic adsorbent is not particularly limited. For example, the form may be such that the solid basic adsorbent or the acidic adsorbent is attached to the surface of the non-porous substrate, or such that the non-porous substrate is covered with a liquid phase containing the basic adsorbent or the acidic adsorbent.

[0036] The liquid phase is a liquid containing the basic adsorbent or the acidic adsorbent, and optionally contains a solvent. In other words, if the basic adsorbent or the acidic adsorbent is solid, the liquid phase can be prepared by dissolving the basic adsorbent or the acidic adsorbent in a solvent. The solvent is not particularly limited and can be any solvent that can dissolve the basic adsorbent or the acidic adsorbent and does not adversely affect the non-porous substrate. Specific examples of the solvent include water, hydrogen peroxide, ethanol, acetonitrile, and mixtures thereof. The solvent is preferably a water-containing solvent, such as a mixture of water and a non-water solvent from the specific examples of the solvents listed above, and more preferably a solvent consisting solely of water. On the other hand, if the basic adsorbent or the acidic adsorbent is liquid, the basic adsorbent or the acidic adsorbent can be used as the liquid phase as is.

[0037] In one embodiment of the present invention, the method for coating the nonporous substrate with the liquid phase is not particularly limited. Examples of such methods include applying the liquid phase to the nonporous substrate, and immersing the nonporous substrate in the liquid phase, then lifting it out and drying it. Specific examples of methods for applying the liquid phase to the nonporous substrate include a method in which the liquid phase is passed through the porous substrate. Here, the term "passing through" refers to passing the liquid phase through a container, such as a column, filled with the porous substrate. If the drying conditions are high temperature and long time, the solvent in the liquid phase may evaporate, and the solid basic adsorbent or acidic adsorbent may precipitate on the surface of the nonporous substrate. In such cases, the nonporous substrate can be obtained in a form in which the solid basic adsorbent or acidic adsorbent is attached to the surface.

[0038] In one embodiment of the present invention, the nonporous substrate may further contain a humectant. In the nonporous substrate further containing a humectant, if the basic adsorbent or the acidic adsorbent is held in the form of a liquid phase, the liquid phase may further contain the humectant. Examples of the humectant include polyhydric alcohols such as ethylene glycol, propylene glycol, and glycerin; and polyalkylene glycols such as polyethylene glycol and polypropylene glycol. The content of the humectant may be 0.01 wt % or more and 1.0 wt % or less, and preferably 0.1 wt % or more and 0.5 wt % or less, based on the total weight of the nonporous substrate covered with the liquid phase.

[0039] (Configuration of the collection adsorption column) The adsorption column for collection may be composed of a housing (i.e., an exterior part) and a frit, which is a filter for preventing the non-porous substrate disposed inside the housing from leaking out. The materials for the housing and the frit are not particularly limited, as long as they do not affect the acid or base components to be collected and are not adversely affected, such as by corrosion, by the basic adsorbent or the acidic adsorbent. Examples of materials for the housing include polypropylene, glass, polyethylene (PE), polyether ether ketone (PEEK), polyvinyl chloride (PVC), polystyrene (PS), ABS resin (ABS), methacrylic resin, acrylic resin (PMMA), polyamide (PA), polyacetal (POM), polycarbonate (PC), modified polyphenylene ether (mPPE), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polysulfone (PSU), polyarylate (PAR), fluororesin (PFA), and mixtures thereof. Examples of materials for the frit include polyethylene, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyethersulfone (PES), cellulose, glass fiber, carbon fiber, diatomaceous earth, cellulose, polyethylene terephthalate (PET), nylon, and mixtures thereof. The materials of the housing and the frit may be the same or different.

[0040] The shape of the adsorption column is not particularly limited, and a cylindrical column is usually used. The adsorption column is preferably a column consisting of a column body, a frit, a sleeve, and end fittings, such as that described in JP-A-2001-249120.

[0041] The internal volume of the collection adsorption column (the internal volume of the housing) can be set to an appropriate size depending on the amount of analysis to be processed, and the volume is, for example, 0.6 ml to 5 ml, 0.6 ml to 3 ml, or 0.7 ml to 2 ml.

[0042] The void volume of the present collection adsorption column refers to the volume of the gaps in the present collection adsorption column that are not filled with the non-porous substrate covered with the liquid phase. The void volume can be measured, for example, by the method described in the Examples. The larger the void volume, the greater the amount of gas passing through the present collection adsorption column per unit time when capturing acid or base components in the gas, i.e., the greater the airflow rate. Here, when performing quantification using the present collection adsorption column, a predetermined amount of gas is sampled into the present collection adsorption column, the gas is passed through, and the acid or base components contained in the predetermined amount of gas are captured. Therefore, the larger the void volume, the shorter the time required to sample and pass the predetermined amount of gas through the present collection adsorption column. Therefore, in the present collection adsorption column, the larger the void volume, the shorter the time it takes to capture and quantify the acid or base components in the gas.

[0043] From the viewpoint of quantifying the acid or base components in a gas in a shorter time using this adsorption column for collection, the void volume is preferably 200 μL or more, more preferably 300 μL or more, and even more preferably 400 μL or more.

[0044] On the other hand, when the void volume is equal to or less than a predetermined value, the amount of non-porous substrate carrying the basic or acidic adsorbent in the adsorption column is sufficiently large, ensuring sufficient ability to capture the acid or base components in the gas. Therefore, the adsorption column can capture and quantify the acid or base components in the gas with higher sensitivity. From the viewpoint of capturing and quantifying the acid or base components in the gas with higher sensitivity, the void volume is preferably equal to or less than 5000 μL, more preferably equal to or less than 3000 μL, even more preferably equal to or less than 600 μL, and particularly preferably equal to or less than 500 μL.

[0045] The porosity of the present collection adsorption column can be defined as "porosity (%) = void volume ÷ internal volume of the present collection adsorption column × 100." In this case, the lower limit of the porosity of the present collection adsorption column is not limited and may be, for example, 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, or 70% or more. On the other hand, the upper limit of the porosity of the present collection adsorption column is not limited and may be, for example, 90% or less, 80% or less, or 70% or less. The above configuration is preferable in that it can fully exhibit the effect of preventing a decrease in the suction speed during air sampling due to low porosity while not reducing the amount of acid or base components adsorbed to the adsorbent.

[0046] The upper limit of the pressure drop of this collection adsorption column when gas is drawn into the column at a suction rate of 2.0 L / min is 10 kPa or less. Hereinafter, the pressure drop when drawing gas at a suction rate of 2.0 L / min is referred to as "pressure drop A." As described above, when quantitative measurement is performed using this collection adsorption column, a predetermined amount of gas must be drawn into the collection adsorption column and passed through it to capture the acid or base components contained in the predetermined amount of gas. By setting the pressure drop A to 10 kPa or less, the gas to be measured can be drawn into the collection adsorption column at high speed without placing a load on the gas drawing suction pump. This allows a predetermined amount of gas to be drawn into the collection adsorption column and passed through it in a short period of time. Therefore, this collection adsorption column allows the acid or base components in gas to be drawn and quantified in a short period of time.

[0047] From the viewpoint of quantitatively determining the amount of acid or base components in a gas in a short period of time using the present adsorption column for collection, the upper limit of the pressure drop A is preferably 7 KPa or less, and more preferably 5 KPa or less.

[0048] [Embodiment 2] A capture method according to one embodiment of the present invention (hereinafter also referred to as "the capture method") is a method for capturing acidic or basic components in a gas, in which the gas is passed through the capture adsorption column and the acidic or basic components in the gas are captured.

[0049] The present collection method uses the present adsorption column to collect acid or base components in a gas. As described above, the present adsorption column can collect trace amounts of acid or base components in a gas in a short period of time. Therefore, the present collection method can be used to collect and quantify acid or base components in a gas in a short period of time with high sensitivity.

[0050] Hereinafter, the present collection method, which uses an acid component adsorption column to collect the concentration of acid components in a gas, will also be referred to as the "acid component collection method." Furthermore, the present collection method, which uses a base component adsorption column to collect the concentration of base components in a gas, will also be referred to as the "base component collection method." The present collection method is a method for collecting acid components or a method for collecting base components.

[0051] The configuration of the adsorption column for use in this collection method is the same as that described in [Embodiment 1: Adsorption column for collection]. The acid and base components to be quantified in this collection method are not particularly limited and may be any of the acid and base components exemplified in the section [Embodiment 1: Adsorption column for collection] above.

[0052] Here, both the acid component collection method and the base component collection method can be carried out on the same gas together to collect both the acid component and the base component in the gas.

[0053] In this method, the gas to be collected is passed through the adsorption column, and the acidic or basic components in the gas are adsorbed onto the non-porous substrate carrying the acid component adsorbent or the base component adsorbent, thereby being collected. The aeration is usually carried out using a suction pump.

[0054] In this collection method, by passing the gas through an adsorption column for collecting the acid or base components in the gas at a higher flow rate, the time required to collect the acid or base components in the gas can be shortened in the collection step. As a result, the collection method allows the acid or base components in the gas to be collected and quantified in a short time. From the viewpoint of collecting and quantifying the acid or base components in the gas in a short time, the flow rate is preferably 2.0 L / min or more, more preferably 3.0 L / min or more. On the other hand, if the flow rate is excessively high, the pressure applied to the adsorption column when passing the gas through the column increases, which may damage the adsorption column. From the viewpoint of effectively preventing damage to the adsorption column, the flow rate is preferably 10 L / min or less, more preferably 7 L / min or less. From the viewpoint of being excellent in both the time required for the metered amount and the prevention of breakage, it is particularly preferable that the aeration flow rate is 5 L / min.

[0055] The ventilation of the collection adsorption column is usually carried out in the space to be evaluated, such as a clean room, a clean booth, etc. The collection adsorption column is transported by sealing the opening of the column with a stopper that is not contaminated by the analyte and / or by storing the column in a sealed container that is not contaminated by the analyte.

[0056] When the acid component collection method and the base component collection method are carried out together, the acid component collection method and the base component collection method may be carried out continuously using an apparatus having an acid component adsorption column and a base component adsorption column arranged in series. That is, the air may be sucked into the apparatus and continuously passed through both the acid component adsorption column and the base component adsorption column constituting the apparatus. More specifically, (i) air that has passed through the acid component adsorption column may be passed through the base component adsorption column, or (ii) air that has passed through the base component adsorption column may be passed through the acid component adsorption column. In this case, the acid component adsorption column and the base component adsorption column may be connected directly or via a connecting pipe.

[0057] [Embodiment 3: Quantitation method] A quantification method according to one embodiment of the present invention (hereinafter also referred to as "this quantification method") is a method for quantifying the concentration of an acid component or a base component in a gas, comprising: a collection step of collecting an acid component or a base component in the gas using this collection method; an elution step of passing a solvent through the collection adsorption column that has collected the acid component or the base component, thereby eluting the collected acid component or the base component into the solvent to obtain an eluate; and a measurement step of measuring the concentration of the acid component or the base component in the eluate.

[0058] This quantitative determination method utilizes the present collection method using the present collection adsorption column to capture and quantify acid or base components in gas. As described above, the present collection adsorption column and the present collection method allow acid or base components in gas to be captured and quantified in a short time with high sensitivity. Therefore, the present quantitative determination method also allows acid or base components in gas to be captured and quantified in a short time with high sensitivity.

[0059] Hereinafter, this method for quantifying the concentration of an acid component in a gas using an acid component adsorption column will also be referred to as the "method for quantifying an acid component." Furthermore, this method for quantifying the concentration of a base component in a gas using a base component adsorption column will also be referred to as the "method for quantifying a base component." This method is either a method for quantifying an acid component or a method for quantifying a base component.

[0060] The configuration of the adsorption column for collection used in this quantitative determination method is the same as that described in [Embodiment 1: Adsorption column for collection]. The acid and base components to be quantified in this quantitative determination method are not particularly limited and may be the acid and base components exemplified in the section [Embodiment 1: Adsorption column for collection] above.

[0061] Here, both the acid component quantitative determination method and the base component quantitative determination method can be performed on the same gas to simultaneously quantify the acid component and the base component in the gas. Furthermore, this quantitative determination method can be performed offline, in which the collection step and elution step described below are performed on the collection adsorption column without being connected to a measuring device that measures the concentration of the acid component or the base component in the eluate.

[0062] (Collection process) This quantitative determination method includes a collection step of collecting an acid component or a base component in the gas using this collection method. Note that the configuration of this collection method used in the collection step is the same as that described in [Embodiment 2: Collection method].

[0063] When the acid component quantitative determination method and the base component quantitative determination method are carried out in combination, the trapping steps in each of the acid component quantitative determination method and the base component quantitative determination method may be carried out simultaneously in the same manner as in the case of carrying out the acid component trapping method and the base component trapping method in combination described above. That is, the air may be sucked into an apparatus having an acid component adsorption column and a base component adsorption column arranged in series, and the air may be simultaneously passed through both the acid component adsorption column and the base component adsorption column that make up the apparatus. Thereafter, the acid component adsorption column and the base component adsorption column may be separated from the apparatus, and the elution step and measurement step described below may be carried out for each.

[0064] (Elution process) This quantification method includes an elution step in which a solvent is passed through the adsorption column for collection in which the acid component or the base component has been collected, thereby eluting the collected acid component or the base component into the solvent to obtain an eluate.

[0065] In the elution step, the acid component or the base component captured by the adsorption column is eluted into the solvent, resulting in an eluate containing the acid component or the base component. The solvent is not particularly limited as long as it can elute the acid component or the base component. From the viewpoint of the sensitivity of the present quantification method, it is preferable to use a solvent that does not contain impurities that may cause a decrease in sensitivity, or that contains only a minimal amount of such impurities. From this perspective, it is particularly preferable to use pure water as the solvent. Here, pure water refers to water with an electrical resistivity in the range of 0.1 MΩ·cm or more and 18 MΩ·cm or less.

[0066] (Measurement process) This quantitative method includes a measuring step of measuring the concentration of the acid component or the base component in the eluate.

[0067] The acid component or the base component in the eluate is the same as the acid component or the base component in the gas captured in the capturing step. Therefore, the concentration of the acid component or the base component in the eluate measured in the measuring step corresponds to the concentration of the acid component or the base component in the gas. Therefore, the measuring step can quantify the concentration of the acid component or the base component in the gas.

[0068] The method for measuring the concentration of the acid component or the base component in the eluate (hereinafter also referred to as the "measurement method") can be a known method and is not particularly limited. The measurement method can be, for example, a liquid chromatography method. Examples of the liquid chromatography method include an anion exchange method using an ion exchange column, a cation exchange method, and a suppressor type ion chromatography method using a suppressor.

[0069] The acid component exists as an anion in the eluate, and the base component exists as a cation in the eluate. Therefore, the total concentration of anions in the eluate is measured by the above-mentioned method, and the measured value of the concentration is used as the concentration of the acid component. Similarly, the total concentration of cations in the eluate is measured by the above-mentioned method, and the measured value of the concentration is used as the concentration of the base component.

[0070] [Embodiment 4: Method for managing the cleanliness of a space] A method for managing the cleanliness of a space according to one embodiment of the present invention (hereinafter also referred to as "this management method") is a method for managing the cleanliness of a space, comprising: a quantification step of quantifying the concentration of an acid component or a base component in a gas in a space using this quantification method; and a step of identifying and excluding a source of the acid component or base component in the gas inside the space when the concentration of the acid component or base component quantified in the quantification step exceeds a threshold value.

[0071] According to this management method, the concentration of an acid or base component, which is a contaminant in a space, is quantified in a short time with high sensitivity in the quantification step. Then, when the quantified concentration of the acid or base component exceeds a specific threshold, the method proceeds to a step of identifying and eliminating the source of the acid or base component in the gas inside the space.

[0072] Since the quantification can be performed with high sensitivity, the present management method allows the predetermined threshold to be set to a low value. Therefore, according to the present management method, by setting the predetermined threshold to a low value, it is possible to identify and eliminate the contamination source at a stage when the amount of the contaminant acid component or base component is small, thereby ensuring a highly clean space. Furthermore, since the quantification can be performed in a short time, the time from the start of the quantification to the completion of identification and elimination of the contamination source can be shortened, resulting in a highly clean space being easily ensured. Therefore, according to the present management method, a highly clean space can be easily ensured. In this specification, the term "contamination source" means "a source of the acid component or base component in the gas inside the space."

[0073] (Quantitative process) This management method includes a quantification step of quantifying the concentrations of acidic and basic components in the gas in the space using the quantification method. By carrying out the quantification step, the concentrations of acidic and basic components, which are contaminants in the gas in the space, can be easily quantified.

[0074] The space in this specification refers to a space that is the subject of evaluation using the present adsorption column for the aforementioned quantitative analysis, and may be, for example, a space in which the concentrations of the acid component and the base component as contaminants are required to be below a specific threshold value for the purpose of performing operations such as the manufacture of electronic substrates. The space in this management method may typically be a space having a predetermined volume formed by walls, a floor, etc. The space is not particularly limited, and examples thereof include a clean room, a clean booth, and the space inside a manufacturing device.

[0075] The configuration and the like of the quantification method in the quantification step are the same as those described in [Embodiment 3: Quantification method] above.

[0076] In this control method, to ensure a highly clean space, the amount (concentration) of the acid component and / or the base component, which are contaminants in the gas in the space, is quantified. Then, based on the quantified concentrations, the source of contamination is identified and eliminated. Therefore, in the quantification step, either the acid component quantification method or the base component quantification method may be performed, or both the acid component quantification method and the base component quantification method may be performed simultaneously. However, it is preferable to perform both the acid component quantification method and the base component quantification method simultaneously. To perform these simultaneously, it is preferable to use an apparatus having the aforementioned acid component adsorption column and base component adsorption column arranged in series. When using this apparatus, a single suction operation can be performed on both the acid component adsorption column and the base component adsorption column, simplifying the quantification step and this control method.

[0077] (Process of identifying and eliminating the source of contamination) This management method includes a step of identifying and eliminating a source of contamination when the concentration of the acid or base component quantified in the quantification step exceeds a threshold value. By carrying out this step, the concentration of the acid or base component, which is a contaminant, inside the space can be controlled to be equal to or lower than the threshold value, thereby ensuring a highly clean space.

[0078] The threshold value in the process can be appropriately determined depending on the type of operation performed in the space and the quality required for the product manufactured by the operation, and is not particularly limited. For example, when manufacturing high-quality electronic substrates in the space, the threshold value is 1.0 μg / m 3 , 0.1 μg / m 3 or 0.01 μg / m 3 etc.

[0079] Identifying and eliminating the source of contamination means grasping the concentrations of the acid components and base components, which are contaminants inside the space, and taking appropriate measures. The specific method for this is not particularly limited, and any known method can be used.

[0080] One embodiment of the present invention may be the inventions shown in [1] to [7] below. [1] An adsorption column for collecting acid or base components in a gas, a non-porous substrate is filled, the non-porous substrate retaining a basic adsorbent for adsorbing an acid component or an acidic adsorbent for adsorbing a base component; the pressure loss when the gas in the collection adsorption column is sucked through the collection adsorption column at a suction rate of 2.0 L / min is 10 kPa or less; An adsorption column for capturing acid or base components in gas. [2] The adsorption column for collection according to [1], wherein the void volume of the adsorption column for collection is 200 μL or more and 3000 μL or less. [3] The adsorption column for collection according to [1] or [2], wherein the amount of the basic adsorbent or the acidic adsorbent is 0.4 μeq or more and 50 μeq or less. [4] A method for collecting an acid component or a base component in a gas, comprising passing the gas through the adsorption column described in any one of [1] to [3] and collecting the acid component or the base component in the gas. [5] The method for collecting an acid component or a base component in a gas, comprising passing the gas through the adsorption column described in [4] at a flow rate of 2.0 L / min or more. [6] A capturing step of capturing an acid component or a base component in the gas using the capturing method according to [4] or [5]. an elution step of passing a solvent through the adsorption column in which the acid component or the base component has been collected, thereby eluting the collected acid component or the base component into the solvent to obtain an eluate; and a measuring step of measuring the concentration of the acid component or the base component in the eluate. [7] A quantitative determination step of quantifying the concentration of an acid component or a base component in a gas in a space using the quantitative determination method described in [6]; and A method for managing the cleanliness of a space, comprising a step of identifying and eliminating a source of the acid component or base component in the gas inside the space when the concentration of the acid component or base component quantified in the quantification step exceeds a threshold value. [Example]

[0081] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0082] [Measurement method] The methods for measuring the physical properties of the adsorption column for collection described in the examples are as follows.

[0083] (weight) In this example, the weight of the collection adsorption column was measured using a weighing scale (manufacturer: Mettler Toledo K.K., product name: electronic non-automatic scale PB3003-L).

[0084] (void volume) The collection adsorption column described in the Examples was dried by passing compressed air through it at a flow rate of 2 L / min for 17 hours. The weight of the dried collection adsorption column was measured. The measured value was designated W0 (g). Next, room temperature pure water was introduced into the dried collection adsorption column, and the interior of the collection adsorption column was filled with the pure water. The weight of the collection adsorption column filled with the pure water was measured. The measured value was designated W1 (g). Here, the density of the pure water was set to 1 g / cm. 3 Specifically, the void volume was calculated based on the following formula (1) assuming that the void volume was the same value as the weight W2 (g) of pure water packed in the collection adsorption column. Void volume of the adsorption column for collection (cm 3 ) = W2(g) = W1(g) - W0(g)…(1) (Equivalent amount of basic adsorbent contained in the acid component adsorption column and acidic adsorbent contained in the base component adsorption column) 10 mL of pure water was passed through the acid component adsorption column described in the Examples to elute the basic adsorbent in the acid component adsorption column, thereby obtaining a first eluate. Subsequently, 40 mL of pure water was passed through the acid component adsorption column after the 10 mL of pure water had been passed through, thereby eluting the basic adsorbent in the acid component adsorption column, thereby obtaining a second eluate. Each of the first eluate and the second eluate was subjected to ion chromatography, and the equivalent weight of the basic adsorbent contained in each eluate was measured. The sum of the equivalent weights of the basic adsorbent contained in each measured eluate was taken as the equivalent weight of the basic adsorbent contained in the acid component adsorption column.

[0085] Similarly, 10 mL of pure water was passed through the base component adsorption column described in the Examples to elute the acidic adsorbent in the base component adsorption column, yielding a first eluate. Subsequently, 40 mL of pure water was passed through the base component adsorption column after the 10 mL of pure water had been passed through, yielding a second eluate. Each of the first and second eluates was subjected to ion chromatography, and the equivalent weight of the acidic adsorbent contained in each eluate was measured. The sum of the equivalent weights of the acidic adsorbent contained in each measured eluate was taken as the equivalent weight of the acidic adsorbent contained in the base component adsorption column.

[0086] (pressure loss) A gas suction pump was connected to the adsorption column for collection described in the examples, and suction was performed at a suction rate of 2.0 L / min. The pressure loss during this process was measured with a differential pressure gauge. In this example, a gas suction pump manufactured by Shibata Scientific Co., Ltd., product name: Mini Pump-MP MP-Σ300, was used for the pressure loss measurements and in Examples 3 to 5 described below.

[0087] (ion chromatography) The measurement method using an ion chromatograph used to measure the equivalent weight of the basic adsorbent and acidic adsorbent shown above, and to measure the amount of attached anions and cations described in Examples 3 to 5 below, was as follows.

[0088] The eluate was analyzed using an ion chromatography system with electrolysis suppression and conductivity detection. The anion channel of the ion chromatography system uses a potassium hydroxide (KOH) eluent gradient and inorganic and organic acid anion analytical columns. The cation channel of the ion chromatography system uses a methanesulfonic acid eluent gradient and a cation analytical column.

[0089] [Example 1: Production of acid component adsorption column] 0.9 g of quartz particles with particle diameters of 0.5 mm to 1.0 mm was packed into a cylindrical polypropylene column housing with an internal volume of 0.92 mL. After passing methanol through the column, the column was washed by passing ultrapure water (resistivity 18 MΩ cm) through the column.

[0090] After the washing, an aqueous solution of sodium carbonate and glycerin was passed through the column, and then clean air was passed through the column to dry it, thereby producing an acid component adsorption column.

[0091] The physical properties of the acid component adsorption column were measured by the method described above. As a result, the void volume of the acid component adsorption column was 0.44 cm 3 The equivalent weight of the adsorbent contained was 1.80 μeq, and the pressure loss when suctioned at a suction rate of 2.0 L / min was 2.73 kPa.

[0092] [Example 2: Production of base component adsorption column] 0.9 g of quartz particles with particle diameters of 0.5 mm to 1.0 mm was packed into a cylindrical polypropylene column housing with an internal volume of 0.92 mL. After passing methanol through the column, the column was washed by passing ultrapure water (resistivity 18 MΩ cm) through the column.

[0093] A mixed aqueous solution of sulfuric acid and glycerin was passed through the washed column, and then clean air was passed through the column to dry it, thereby producing a base component adsorption column.

[0094] The physical properties of the prepared base component adsorption column were measured by the method described above. As a result, the void volume of the base component adsorption column was 0.44 cm 3 The equivalent weight of the adsorbent contained was 1.01 μeq, and the pressure loss when suctioned at a suction rate of 2.0 L / min was 2.70 kPa.

[0095] Example 3: Elution from a collection adsorption column that collected air in a clean booth The acid component adsorption column prepared in Example 1 and the base component adsorption column prepared in Example 2 were each connected to a gas suction pump, and air from a clean booth in a laboratory was passed through them at a suction rate of 2.0 L / min for 5 hours.

[0096] After the aeration, ultrapure water was passed through the acid component adsorption column and the base component adsorption column at 2 mL / min for 5 minutes to obtain an eluate containing the anions and cations, i.e., acid and base components, eluted from the columns. The resulting eluate was subjected to ion chromatography to measure the concentrations (unit: ng / mL) of the anions and cations, i.e., acid and base components, in the eluate. The lower limit of quantitation was also determined from the results of a similar procedure performed without sampling air. The measured lower limit of quantitation and the concentrations of acid and base components in the eluate are listed in Table 1. In Table 1, the acid component adsorption column is referred to as "Column A," and the base component adsorption column is referred to as "Column B." The concentrations of acid and base components in the eluate are simply referred to as "concentrations in the eluate."

[0097] [Table 1]

[0098] [Example 4: Analysis results of air in clean booth] A quantitative measurement apparatus having the configuration shown in Fig. 1 was produced. Specifically, the acid component adsorption column 1 produced in Example 1 and the base component adsorption column 2 produced in Example 2 were connected via a connecting pipe 4, and the quantitative measurement apparatus was produced by connecting the base component adsorption column 2 to a suction pump 3 on the side opposite to the side connected to the acid component adsorption column 1.

[0099] The side of the acid component adsorption column 1 in the quantitative measurement device opposite the side connected to the base component adsorption column 2 was connected to a clean booth equipped with a chemical filter. Subsequently, using a suction pump 3, air was drawn into both the acid component adsorption column 1 and the base component adsorption column 2 at a flow rate of 2 L / min for 5 hours to aerate them. After the aeration, 10 mL of pure water was passed through each of the acid component adsorption column 1 and the base component adsorption column 2 to obtain eluates (4a) and (4b). The eluates (4a) and (4b) were each subjected to ion chromatography to quantify the concentrations of anions (i.e., acid components) in the eluate (4a) and cations (i.e., base components) in the eluate (4b). The concentrations of acid components and base components in the air in the clean booth were calculated by multiplying the quantified concentrations in the obtained eluates (4a) and (4b) by the volume of the eluate and dividing the result by the volume of the air sampled. The same procedure was carried out without sampling air, and the lower limit of quantification was calculated from the results. The calculation of each concentration and the lower limit of quantification was carried out twice, and the average of the two calculated values ​​was used as each concentration and the lower limit of quantification.

[0100] The calculated lower limit of quantitation and the concentrations of acid and base components in the clean booth are shown in Table 2 below. As in Table 1, in Table 2 the acid component adsorption column is referred to as "Column A" and the base component adsorption column is referred to as "Column B." In addition, in Table 2, the concentrations of acid and base components in the clean booth are simply referred to as "concentrations in the clean booth."

[0101] [Table 2]

[0102] [Example 5: Results of periodic analysis of the air in the clean booth] The concentrations of acidic and basic components in the air within the clean booth, as well as the lower limit of quantification, were calculated using the same method as in Example 4 for the clean booth immediately after startup and one month, two months, and three months after startup.

[0103] The calculated lower limit of determination and the concentrations of the acid and base components in the clean booth are shown in Table 3. As in Table 2, in Table 3, the acid component adsorption column is referred to as "Column A," the base component adsorption column is referred to as "Column B," and the concentrations of the acid and base components in the clean booth are simply referred to as "concentrations in the clean booth."

[0104] [Table 3]

[0105] [result] As shown in Examples 1 and 2, the collection adsorption columns produced in Examples 1 and 2 satisfy the following requirements (i) to (iii), and therefore correspond to the present collection adsorption columns. (i) The non-porous substrate is filled. (ii) The non-porous substrate carries a basic adsorbent for adsorbing acidic components or an acidic adsorbent for adsorbing basic components. (iii) The pressure loss when gas is sucked into the collection adsorption column at a suction rate of 2.0 L / min is 10 kPa or less.

[0106] Furthermore, from the description of Examples 4 and 5, the methods for capturing acid and base components in Examples 4 and 5 correspond to the present capture method, since they involve passing a gas through the present capture adsorption column and capturing the acid or base components in the gas.

[0107] Furthermore, from the description of Examples 4 and 5, the methods for quantifying acid components and base components in Examples 4 and 5 include the following steps (iv) to (vi) for quantifying the concentrations of acid components or base components in a gas, and therefore fall under the present quantification method. (iv) a collection step of collecting the acid or base components in the gas using the collection method of the present invention, and (v) an elution step of passing a solvent through the adsorption column in which the acid or base components have been collected, thereby eluting the collected acid or base components into the solvent to obtain an eluate. (vi) A measuring step of measuring the concentration of the acid component or the base component in the eluate.

[0108] Furthermore, the descriptions in Examples 3 to 5 and Tables 1 to 3 demonstrate that the collection and quantification methods using the collection adsorption columns produced in Examples 1 and 2 enable high-sensitivity collection and quantification of acid and base components even when the aeration time is as short as 5 hours. Similarly, the descriptions in Examples 4 and 5 and Tables 2 and 3 demonstrate that the collection and quantification methods in Examples 4 and 5 enable high-sensitivity collection and quantification of acid and base components even when the aeration time is as short as 5 hours.

[0109] Therefore, it was found that the present adsorption column, the present collection method, and the present quantification method can collect and quantify acid or base components in gases in a short time with high sensitivity. Furthermore, it was found that the present management method, which utilizes the present adsorption column and the present quantification method, can quickly identify and remove the contamination source even when the concentration of the contaminant is low, thereby easily ensuring a highly clean space. [Industrial Applicability]

[0110] The present adsorption column, collection method, and quantification method enable the collection and quantification of acid or base components in gases in a short time with high sensitivity. Furthermore, the present management method, which utilizes the present adsorption column, collection method, and quantification method, allows the source of contamination to be identified and removed in a short time, even when the concentration of the contaminant is low, thereby easily ensuring a highly clean space. Therefore, the present adsorption column, collection method, quantification method, and management method can be used to manage spaces where work requiring a highly clean space is performed, such as in the manufacture of electronic circuit boards. [Explanation of symbols]

[0111] 1. Acid component adsorption column 2. Base component adsorption column 3. Suction pump 4 Connecting pipes

Claims

1. An adsorption column for collecting acid or base components in a gas, comprising: The non-porous substrate is filled, the non-porous substrate holds a basic adsorbent for adsorbing an acid component or an acidic adsorbent for adsorbing a base component; the pressure loss when the gas in the collection adsorption column is sucked through the collection adsorption column at a suction rate of 2.0 L / min is 10 kPa or less; An adsorption column for capturing acid or base components in gas.

2. 2. The collection adsorption column according to claim 1, wherein the void volume of the collection adsorption column is 200 μL or more and 3000 μL or less.

3. 2. The collection adsorption column according to claim 1, wherein the amount of the basic adsorbent or the acidic adsorbent is 0.4 μeq or more and 50 μeq or less.

4. A method for capturing an acid component or a base component in a gas, comprising passing the gas through the adsorption column for capture according to any one of claims 1 to 3, and capturing the acid component or the base component in the gas.

5. The collection method according to claim 4, wherein the gas is passed through the collection adsorption column at a flow rate of 2.0 L / min or more.

6. a collection step of collecting an acid component or a base component in the gas using the collection method according to claim 4; an elution step of passing a solvent through the adsorption column in which the acid component or the base component has been collected, thereby eluting the collected acid component or the base component into the solvent to obtain an eluate; and a measuring step of measuring the concentration of the acid component or the base component in the eluate.

7. a quantifying step of quantifying the concentration of an acid component or a base component in a gas in a space using the quantifying method according to claim 6; A method for managing the cleanliness of a space, comprising a step of identifying and eliminating a source of the acid component or base component in the gas inside the space when the concentration of the acid component or base component quantified in the quantification step exceeds a threshold value.

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