JP2008289955A - Humidity-conditioning gas-absorbing agent and humidity-conditioning gas-absorbing implement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a humidity-conditioning gas-absorbing agent capable of efficiently catching an acidic gas by virtue of its moisture absorption property without releasing the acidic gas in discharging moisture, and a humidity-conditioning gas-absorbing implement using the same. <P>SOLUTION: The humidity-conditioning gas-absorbing agent is comprised of an aggregate of porous pellets prepared by pelletizing two primary materials of a powdery humidity-conditioning agent 1 comprising a clay mineral consisting primarily of montmorillonite and a powdery acidic-gas adsorbent 2 and controlling the moisture content of the aggregate. The humidity-conditioning gas-absorbing implement is comprised of a gas permeable bag or container filled with the above agent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a humidity-controlling agent having a humidity-control function and an acid-gas capturing / adsorption function, and being placed in a space to be humidity-controlled to simultaneously control the humidity in this space. The present invention relates to a humidity-controlled gas-absorbing device that captures and adsorbs acidic gas in the interior and prevents deterioration of articles in the space.

  When humidity control and removal of acid gas are required simultaneously in a certain space, in general, a humidity control agent such as silica gel is allowed to stand in this space, and a chemical adsorbent for acid gas is allowed to remain static. The method is used.

  For example, in art museums and museums, in order to prevent deterioration of exhibits, humidity control in these display cases is required, and acid gases such as acetic acid gas that adversely affect these exhibits must be removed. It is where it is done. Such acetic acid gas has a ppb level generated from a cloth adhesive or the like stuck in the display case, but its rapid removal is required as a factor of display deterioration.

Here, when the humidity control agent and the chemical adsorbent are allowed to stand in the display case, the acid gas is physically adsorbed by the humidity control agent and chemically adsorbed by the chemical adsorbent. Since the wetting agent repeatedly absorbs and releases moisture, the component of the acid gas physically adsorbed at the time of moisture absorption is released again into the display case at the time of moisture release. For this reason, in this case, although the concentration of the acid gas in the display case can be gradually reduced, it cannot be lowered rapidly. In addition, when the space where humidity control and removal of acid gas are required at the same time, such as the space in the display case, is narrow, a space where the humidity control agent and the chemical adsorbent are allowed to stand at the same time is provided. In some cases, it cannot be secured. If the humidity control agent and the chemical adsorbent are simply mixed, the static space can be reduced, but when the mixed humidity control agent is released, the components of the physically adsorbed acid gas are released again. There is no change in the point. As a humidity-controlling and gas-absorbing molded product formed by kneading and molding a thermoplastic resin together with a humidity control agent and a gas adsorbent, there is one shown in Patent Document 1, but the one shown in Patent Document 1 is also humidity control The adsorbent and the adsorbent are not uniformly mixed and tied, and are not different from the case where the two are simply mixed.
JP-A-8-217913

  The main problem to be solved by the present invention is that the moisture-controlling agent that efficiently captures the acid gas by utilizing the moisture absorption property and does not release the acid gas captured at the time of moisture release, and The object is to provide a humidity-controlled gas-absorbing device using this.

  In order to achieve the above-mentioned object, in the present invention, the moisture-adsorbing agent includes a moisture-conditioning material in the form of a powder made of a clay mineral mainly composed of montmorillonite, and an adsorbent for the acidic gas in the form of a powder. The water content was adjusted for an aggregate of porous granules obtained by granulating as a main raw material.

  In addition, the humidity-adjusting and gas-absorbing device is formed by sealing the humidity-adjusting and absorbing agent in a bag or container having air permeability.

  According to the humidity control gas absorbent according to the present invention, while the acid gas is efficiently captured by utilizing the moisture absorption characteristics of the contained humidity control material, the moisture absorbent is integrated with the humidity control material at the time of moisture release. The trapped acid gas is not released, and as a result, the concentration of the acid gas in the space in which it is placed can be rapidly reduced. In addition, according to the humidity control apparatus according to the present invention, the humidity control device in the space is controlled by the enclosed humidity control gas absorbent by leaving it in a space where humidity control and removal of acid gas are required. The concentration of acid gas in this space can be rapidly reduced while humidifying.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The humidity control gas absorbent according to this embodiment is an aggregate of porous granules having a humidity control function and an acid gas capture and adsorption function, and is placed in a space to be controlled. In addition to adjusting the humidity in this space, the acidic gas in this space is captured and adsorbed.

  In addition, the humidity control and gas absorption device according to this embodiment is formed by enclosing the humidity control gas absorbent in a bag or container having air permeability and leaving it in the space to be controlled by humidity. It is used to prevent deterioration of articles in the space through humidity control and acid gas removal in the space.

  As such a bag, for example, a bag made of a bag constituent material having air permeability such as a woven mesh or a non-woven fabric and having eyes smaller than the granular material can be used. Moreover, as such a container, for example, a box-shaped body having a smaller air hole than the granular body can be used.

  The humidity-adjusting gas-absorbing agent is obtained by adjusting the moisture content of the aggregate of granules formed by adding a binder to the humidity-adjusting material and the adsorbent as necessary.

  The humidity control material is made of a clay mineral mainly composed of montmorillonite and is in powder form. As such a humidity control material, acid clay, bentonite or the like is used.

  The adsorbent is in a powder form and chemically adsorbs acid gas. As the adsorbent, when the acidic gas to be removed is acetic acid gas, slaked lime (calcium hydroxide) or potassium carbonate is used.

  As the binder, colloidal silica or the like can be used.

  In granulation, the granule is generated, the generated granule is made of a porous structure, and the humidity control material and the adsorbent are made as uniform particles with as many grains as possible. Made to unite. The humidity control material and the adsorbent are kneaded prior to granulation or simultaneously with granulation. In wet granulation, water is added. Granulation can be carried out by well-known methods such as compression granulation, stirring and mixing granulation, rolling granulation, fluidized bed granulation, etc., but the above-mentioned porous structure and homogenization and mixing state of particles of both materials From the viewpoint of homogenization, it was recognized that the granulation was optimally performed by extrusion granulation. Typically, such extrusion granulation produces long and thin granules having a diameter of 1 mm to 3 mm and a length of 4 mm to 8 mm from the humidity control material and the adsorbent as main raw materials.

  Although each material can be mix | blended in the ratio of 40-90 wt% of humidity control materials and 10-60 wt% of adsorbents, from the viewpoint of fully satisfying both humidity control performance and gas adsorption performance, the humidity control material 60 is used. It was recognized that it was optimal to blend in a ratio of ˜80 wt% and adsorbent 20-40 wt%.

  For example, when the humidity adjustment target space is a space that should be maintained at a relative humidity of 55%, the humidity adjustment gas absorbent keeps the humidity adjustment gas absorbent in this space. In this case, the space has a moisture absorption / release characteristic with a relative humidity of 55%. More specifically, such moisture absorption / release characteristics are typically imparted by imparting a certain amount of moisture to the dried moisture conditioning gas absorbent. The amount of water to be applied at this time is, for example, when the moisture-adsorbing agent has a moisture absorption / release characteristic of 55% relative humidity, and the humidity-adsorbing agent dried (for testing) has a relative humidity of 55%. % Until the moisture absorption stops (the state where the weight increase due to the moisture absorption of the humidity control gas absorbent is ceased, hereinafter referred to as the equilibrium state), and the weight before the standing (before moisture absorption) and this equilibrium. It can be grasped by obtaining the difference from the weight in the state.

  The aggregate of granular materials whose moisture has been adjusted in this way, that is, the humidity-adjusting gas-absorbing agent, is packaged in an airtight state, etc., and is unpacked and used for use. Even if it exists in the said humidity control gas absorption tool, it is packaged etc. in an airtight state, is unpacked at the time of use, and is used.

  Such a humidity control gas-absorbing agent is an aggregate of particulates and has a porous structure, and thus has a high humidity control capability and gas adsorption capability. The acid gas in the space where the humidity adjusting gas-absorbing agent is allowed to stand is taken into the particulate matter by the moisture absorbing action of the humidity adjusting material. The incorporated acidic gas component is physically adsorbed on the humidity control material and chemisorbed on the adsorbent. The acidic gas component physically adsorbed on the humidity control material is released by the moisture release action of the humidity control material, but the humidity control material and the adsorbent are integrated without any deviation by granulation. Unlike the case where the adsorbent is simply mixed, the released acid gas component is captured and adsorbed by the adsorbent and does not escape from the particulate matter. That is, according to such a humidity control gas absorbent, the acidic gas is efficiently captured by utilizing the moisture absorption characteristics of the contained humidity control material, and is captured when the moisture is released by the adsorbent integrated with the humidity control material. As a result, the concentration of the acid gas in the space in which it is placed can be rapidly reduced. The image of the structure of one grain of the humidity adjustment gas absorbent concerning FIG. 1 is shown typically. The humidity control material 1 and the adsorbent 2 are integrated without any deviation, and one particle of the humidity control gas absorbent has a porous structure. (In FIG. 1, the hole is indicated by reference numeral 3).

  The following examples and comparative examples 1 and 2 were prepared and tested under the following test conditions.

Example: Aggregate of granules obtained by granulating 70 parts by weight of acid clay, 30 parts by weight of slaked lime, and 5 parts by weight of binder Comparative Example 1: 70 parts by weight of granular acid clay and 30 parts by weight of granular slaked lime Comparative Example 2: Mixture of 70 parts by weight of silica gel and 30 parts by weight of granular slaked lime

(Test conditions)
Example, Comparative Example 1 and Comparative Example 2 were each left in a 50 L sealed container in which 2 g of acetic acid was allowed to stand and allowed to stand for 24 hours to adsorb acetic acid. A glass column having a diameter of 25 mm and a length of 350 mm was filled with Example, Comparative Example 1 and Comparative Example 2 in which acetic acid was adsorbed in a length of 50 mm, and air having a relative humidity of 20% RH was 3.0 L / min. Aeration was performed with a ventilation amount. After 2 hours and 24 hours of aeration, acetic acid gas on the downstream side of the glass column by the gas detector tube method (referred to as detector tube method in the table below) and ion chromatograph method (referred to as IC method in the table below), respectively. Concentration was measured. The results are shown below.

  As compared with Comparative Example 1 and Comparative Example 2, it was found that the amount of acetic acid gas desorbed and released was obviously smaller in Examples than in Comparative Examples 1 and 2.

Conceptual configuration diagram of humidity control gas absorbent

Explanation of symbols

1 Humidity control material 2 Adsorbent 3 Hole

Claims (2)

  Moisture content of a porous granular material obtained by granulation using a moisture conditioning material made of a clay mineral mainly composed of montmorillonite and an acid gas adsorbent made of powder as the main raw material. A humidity-adsorbing gas absorbent.   A humidity-controlled gas-absorbing device obtained by enclosing the humidity-controlled gas-absorbing agent according to claim 1 in a bag or container having air permeability.

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