JP2009113026A - Gas adsorbent and gas adsorbing base stock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas adsorbent which exhibits excellent adsorptive performance to acid malodorous gas of acetic acid or the like and aldehyde-based malodorous gas and the gas adsorptive performance of which is hardly deteriorated by heat. <P>SOLUTION: The gas adsorbent is obtained by depositing an organic silicon compound having an amino group and/or an imino group on a carrier and neutralizing a part or the whole of the amino group and/or the imino group by using at least one acid selected from the group consisting of carbonic acid, formic acid and acetic acid. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gas adsorbent and a gas adsorbing material, and more particularly to a gas adsorbent and a gas adsorbing material that can adsorb an acidic malodor gas such as acetic acid or an aldehyde malodor gas.

  Conventionally, inexpensive activated carbon has been widely used as a material for a gas adsorbent for adsorbing and removing various odorous gases. In addition to activated carbon, porous materials such as silica and alumina are also used as gas adsorbents. However, in these materials, since adsorption of odor gas is mainly due to physical adsorption action to a large number of micropores, a sufficient amount of adsorption may not be obtained depending on the type of gas. In physical adsorption, odorous substances are easily adsorbed while the adsorbed gas tends to be easily desorbed. Therefore, further improvement of performance as a gas adsorbent is required for the above materials.

  In response to such problems, the surface of porous materials such as activated carbon and silica is modified by chemical treatment, and in addition to physical adsorption action, chemical adsorption action is manifested, and attempts to improve adsorption performance Has been made. For example, Patent Documents 1 to 3 below propose an adsorbent in which an organosilicon compound having an amino group is supported on a porous material. Such modification with an amino group is considered to be effective in improving adsorption performance for acidic malodorous gases such as acetic acid and aldehyde-based malodorous gases.

JP-A-8-257346 JP 2000-218159 A JP 2006-312164 A

  The gas adsorbent may be used as it is, but may be used as a material for the gas adsorbing material, such as an air purifier filter or a gas adsorbing sheet. Most of the gas adsorbing materials are usually manufactured by applying a gas adsorbent to a predetermined base material.

  However, when a gas adsorbing material is produced using the gas adsorbents described in Patent Documents 1 to 3, gas adsorbing performance commensurate with the amount used may not be obtained. According to the study by the present inventors, it has been found that the adsorption performance of the gas adsorbent is remarkably deteriorated due to the heat treatment during the production of the gas adsorbing material and the heat history with time.

  The present invention has been made in view of the above-described problems of the prior art, and is excellent in adsorption performance for acidic malodorous gas such as acetic acid and aldehyde-based malodorous gas, and the decrease in gas adsorption performance due to heat is sufficiently small. An object is to provide a gas adsorbent and a gas adsorbing material using the gas adsorbent.

  As a result of intensive investigations to solve the above problems, the present inventors have found that the degradation of gas adsorption performance due to the heat of the conventional gas adsorbent as described above is caused by the amino group derived from the amino group-containing silicon compound supported. It was found that this was largely caused by heat denaturation. Furthermore, when the present inventors examined based on this knowledge, by protecting an amino group using a specific acid, the adsorption performance of the gas adsorbent can be effectively expressed, It has been found that the gas adsorption performance can be sufficiently prevented from being lowered by the above, and the present invention has been completed.

  That is, the gas absorbent of the present invention carries an organosilicon compound having an amino group and / or imino group on a carrier, and a part or all of the amino group and / or imino group is composed of carbonic acid, formic acid and acetic acid. It is obtained by neutralizing with at least one acid selected from the group.

  According to the present invention, by neutralizing part or all of the amino group and / or imino group with the acid, it is excellent in the adsorption performance of acidic malodorous gas such as acetic acid and aldehyde malodorous gas, In addition, it is possible to realize a gas adsorbent excellent in heat resistance with a sufficiently small decrease in gas adsorption performance due to heat.

  In addition, according to the gas adsorbent of the present invention, sufficient gas adsorbability can be maintained even if heat treatment is performed during production of the gas adsorbent material, so that it is possible to efficiently produce a gas adsorbent material having excellent gas adsorbability. It becomes possible.

  In the gas adsorbent of the present invention, the carrier is preferably activated carbon or a metal oxide having a hydroxyl group.

  Furthermore, the metal oxide having a hydroxyl group is preferably silica. In this case, it becomes easy to secure a sufficient amount of the organosilicon compound having an amino group and / or an imino group, and a higher level of gas adsorbability is easily obtained.

  In the gas adsorbent of the present invention, the average particle diameter of the carrier is preferably 1 nm to 5 μm from the viewpoint of obtaining sufficient gas adsorbability more reliably.

  Moreover, this invention provides the gas adsorption raw material formed by providing the gas adsorbent of this invention to a base material. According to the gas adsorbing material of the present invention, acidic odor gas such as acetic acid and aldehyde odor gas can be efficiently adsorbed by being provided with the gas adsorbent of the present invention. In addition, since the gas adsorption material of the present invention can sufficiently suppress a decrease in gas adsorption property due to heat treatment during production or processing of the material and thermal history over time, the productivity or workability, It is possible to achieve both the adsorption performance at a higher level than before.

  According to the present invention, the adsorption performance of aldehyde-based malodorous gases such as formaldehyde and acetaldehyde, and acidic malodorous gases typified by organic acids such as acetic acid and butyric acid is sufficiently excellent, and the gas adsorption performance is reduced by heat. It is possible to provide a gas adsorbent that can be made smaller. In addition, according to the present invention, it is possible to provide a gas adsorbing material capable of maintaining higher adsorption performance for the malodorous gas than in the past even when subjected to heat treatment or thermal history over time. .

  The gas adsorbent of the present invention carries an organosilicon compound having an amino group and / or imino group on a carrier, and part or all of the amino group and / or imino group is selected from the group consisting of carbonic acid, formic acid and acetic acid. And obtained by neutralization with at least one acid.

  The gas adsorbent of the present invention can be obtained, for example, by selecting those that can react with each other as a carrier and the organosilicon compound, reacting them, and then neutralizing with the acid. The organosilicon compound is preferably one in which the amino group and / or imino group can be sufficiently present on the support after the reaction with the support.

  As the carrier, a compound having a hydroxyl group can be used from the viewpoint of good reactivity with an organosilicon compound having an amino group and / or an imino group, and activated carbon or a metal oxide having a hydroxyl group can be used. It is preferable to use it. Examples of the metal oxide having a hydroxyl group include silica, alumina, titania, zirconia, and zinc oxide.

  Activated carbon and hydroxyl group-containing metal oxides have their surfaces immersed in alkali such as alkali metal or alkaline earth metal hydroxides, carboxylates, ammonia, aliphatic or aromatic amines, and amino group-containing polymers. It may be subjected to alkali treatment by a method such as

  In the present invention, it is preferable to use a metal oxide having a hydroxyl group among the above carriers. In this case, when the gas adsorbent is applied to the substrate to obtain the gas adsorbing material, the influence on the hue of the substrate can be further reduced. Further, silica is particularly preferable because it is rich in hydroxyl groups on the surface and can increase the amount of the organosilicon compound having an amino group and / or an imino group.

  The average particle size of the carrier used in the present invention is preferably in the range of 1 nm to 5 μm, more preferably in the range of 1 nm to 1 μm, still more preferably in the range of 1 nm to 500 nm, Most preferably, it is in the range of 1 nm to 200 nm. If the average particle size of the support is less than 1 nm, the ability to support an organosilicon compound having an amino group and / or imino group tends to be poor, and sufficient gas adsorbability tends to be difficult to obtain. Further, even if the average particle diameter exceeds 5 μm, the surface area of the carrier becomes small, and thus there is a tendency that sufficient gas adsorbability is hardly obtained. Furthermore, when the average particle diameter of the carrier is within the above range, it is possible to produce a gas adsorbing material while sufficiently reducing the influence on the hue of the substrate (in particular, suppressing whitening). In addition, when the gas adsorbent is adhered to the substrate, it may be processed by a spray method, but if the average particle size is within the above range, clogging of the spray hardly occurs and the gas adsorbent is sprayed. Suitability can be improved. In the present invention, the average particle diameter means a median diameter of 50% cumulative.

  The organosilicon compound having an amino group and / or imino group used in the present invention has at least one amino group and / or imino group and a functional group capable of reacting with and binding to the functional group of the carrier. Compounds are preferred. In the case where the carrier has a hydroxyl group, examples of the functional group capable of reacting with the hydroxyl group to bind thereto include -SiOH group and -SiOR group (where R represents a hydrocarbon group, preferably carbon And an alkyl group having a number of 1 to 3).

  Examples of the organosilicon compound having such a functional group include 3-aminopropyltrihydroxysilane, methoxy (3-aminopropyl) dihydroxysilane, ethoxy (3-aminopropyl) dihydroxysilane, and γ-aminopropyltrimethoxysilane. Γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropyldimethylethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldiethoxysilane, γ- (2-aminoethyl) aminop Pyrdimethylmethoxysilane, γ- (2-aminoethyl) aminopropyldimethylethoxysilane, γ- (2-aminoethylamino) propyl (isopropoxy) dimethoxysilane, 2- (2-aminoethyl) -3-aminopropyltri Examples include silane coupling agents such as methoxysilane.

  In order to support the organosilicon compound having an amino group and / or imino group on the carrier, for example, the carrier is added to an aqueous solution of the organosilicon compound (usually about 5 to 40% by mass), and at room temperature for 10 minutes to The method of stirring for about 5 hours is mentioned. The amount of the organosilicon compound used is preferably 0.1 to 5 g, more preferably 0.5 to 2 g, relative to 1 g of the carrier.

  In order to neutralize part or all of the amino group and / or imino group with at least one acid selected from the group consisting of carbonic acid, formic acid and acetic acid, for example, the aqueous solution obtained above is adjusted to pH The method of neutralizing by adding one or more of carbon dioxide gas, dry ice, formic acid, and acetic acid until from 1 to 12 to 4 to 10, preferably from 6 to 10 is mentioned. Through such neutralization treatment, an aqueous dispersion containing the gas adsorbent of the present invention can be obtained. In addition, after neutralization, you may add conventionally well-known components, such as a dispersing agent (preferably nonionic surfactant), a thickener, and antiseptic | preservative, as needed. It is also possible to obtain a powdery gas adsorbent by removing water from the aqueous dispersion.

  In the gas adsorbent of the present invention, the amino group and / or imino group derived from the organosilicon compound supported on the carrier is neutralized with one or more acids selected from the group consisting of carbonic acid, formic acid and acetic acid. Thus, even when subjected to heat treatment or a heat history over time, it is possible to have excellent heat resistance that the gas adsorbability with respect to acidic gas such as acetic acid and aldehyde gas is sufficiently maintained. Specifically, the gas adsorbability can be sufficiently maintained up to about 5 minutes at 200 ° C. in the case of heat treatment and up to about 100 hours at 100 ° C. in terms of the heat history over time.

  The present inventors infer the following regarding the mechanism by which heat resistance develops in the gas adsorbability of the gas adsorbent of the present invention. That is, the amino group and / or imino group derived from the organosilicon compound neutralized with the acid described above is deoxidized to a free amino group or imino group even when subjected to heat, so that the modification is difficult to proceed. It is thought that. Therefore, it is considered that a sufficient amount of amino groups and / or imino groups remain after the heat treatment, and the gas adsorption property is maintained.

  In the present invention, at least one acid selected from the group consisting of carbonic acid, formic acid and acetic acid is used as the acid for neutralizing the amino group and / or imino group derived from the organosilicon compound supported on the carrier. This is very important. When a strong acid such as hydrochloric acid or sulfuric acid or an organic acid such as citric acid or malic acid is used as the neutralizing acid, the effect of the present invention cannot be obtained. The reason is considered that the neutralized salt is strong, so that the gas adsorbability itself is lowered and the heat resistance due to the deoxidation is hardly exhibited.

  The gas adsorbent of the present invention can be used as it is because it has sufficient gas adsorbability even without heat treatment.

  Next, the gas adsorption material of the present invention will be described.

  The gas adsorption material of the present invention is obtained by applying the gas adsorbent of the present invention to a base material, and may be appropriately air-dried or heat-treated after application of the gas adsorbent.

  Examples of the substrate include fibers, plastics, paper, glass, activated carbon, ceramics and the like. The fiber material is not particularly limited, and natural fibers such as cotton, hemp, wool and silk, synthetic fibers such as polyester, nylon, acrylic and polyolefin, semi-synthetic fibers such as acetate, regenerated fibers such as rayon and the like. A composite fiber is mentioned.

  The shape in particular of a base material is not restrict | limited, It can select suitably according to a usage form. Moreover, after manufacturing a gas adsorption raw material, it can also be shape | molded suitably as needed.

  As a method for applying the gas adsorbent to the base material, a known method such as spraying or coating using the dispersion of the gas adsorbent of the present invention as it is or appropriately diluted or concentrated with a solvent such as water or alcohol. The method of apply | coating by, the method of immersing, etc. are mentioned. At this time, a binder may be appropriately added to the gas adsorbent or the dispersion thereof. As the binder, conventionally known binders can be used without particular limitation. For example, polyvinyl alcohol, acrylic emulsion, vinyl acetate emulsion, ethylene-vinyl acetate copolymer emulsion, methyl cellulose, acrylic-ethylene copolymer emulsion, urethane type An emulsion, a silicone emulsion, etc. are mentioned.

  Further, as described above, when the gas adsorbent of the present invention is obtained as a dispersion containing a solvent such as water, the powdered gas adsorbent obtained by distilling off the solvent from the dispersion, the binder, And the mixture can be applied to a substrate.

  About the usage-amount of a binder, when there are too many binders, gas adsorption property may fall. Therefore, the amount of the binder used is up to 0.1 g, preferably 0.02 to 0.5 g with respect to 1 g of the gas adsorbent, in order to balance the retention of the gas adsorbent on the base material and the gas adsorbability. It is good to do.

  After applying the gas adsorbent to the substrate, heat treatment can be performed under appropriate conditions depending on the type and amount of the substrate.

  Furthermore, the method for producing the gas adsorbing material of the present invention will be described with reference to specific examples. For example, when the substrate is a textile product, particularly when the substrate is a fabric such as a woven fabric, a knitted fabric, or a nonwoven fabric, a treatment liquid containing a gas adsorbent is prepared and applied to the substrate, or the treatment liquid A gas adsorbent can be applied to the substrate by a method of immersing the substrate. Thereafter, the gas adsorption material is obtained by heating and drying the base material. As a dispersion medium for the gas adsorbent in the treatment liquid, water, lower alcohols such as methanol and ethanol are preferable from the viewpoint of environment and safety.

  The concentration of the gas adsorbent in the treatment liquid is appropriately set depending on the purpose and application of the gas adsorbing material to be manufactured. However, when the gas adsorbing property, texture, appearance, and the like are taken into consideration, the content of the gas adsorbing agent is 0. It is preferable that it is 001-3 mass%.

  In addition to the gas adsorbent of the present invention, the above-described treatment liquid appropriately contains conventionally known components used for fiber processing, such as antibacterial agents, flame retardants, antistatic agents, softeners, antifungal agents, and the like. It can be included.

  As heat drying conditions, heat treatment conditions in ordinary fiber products can be applied. In the present invention, excellent gas adsorbability can be achieved even when heat drying is performed at 200 ° C. under a heat treatment condition of up to about 5 minutes.

  Examples of the gas adsorbing material of the present invention include various types such as air purifier filters, gas adsorbing sheets, interior materials such as wallpaper, curtains and carpets, and gas adsorbing decorative materials such as car seats and automotive interior materials such as ceiling materials. The member can be used in a space where gas adsorption is required. These members composed of the gas-adsorbing material of the present invention maintain the ability to adsorb and remove acidic gases and aldehyde-based gases higher than before even when subjected to heat treatment and thermal history over time. Is possible. In addition, the above-mentioned member is excellent in productivity and workability because it can maintain gas adsorbability at a higher level than before even when heat treatment is performed in the manufacturing process. Can be a thing.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples.

<Manufacture of gas adsorption material>
Example 1
Addition of 67 g of γ- (2-aminoethyl) aminopropyltrimethoxysilane to 437 g of colloidal silica (Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle size 10-20 nm, silica content 30% by mass) The reaction solution was stirred at room temperature for about 2 hours. Next, carbon dioxide gas was blown into the reaction solution until the pH of the reaction solution reached 9, neutralization treatment was performed, 496 g of water was further added, and water dispersion with a gas adsorbent concentration of 20 mass% was added. A liquid was obtained. The pH of the reaction solution before neutralization was 11.6.

  Next, the aqueous dispersion obtained above was diluted 50 times to prepare a 0.4 mass% gas adsorbent aqueous dispersion (treatment liquid). ) (Made by Color Dyeing Co., Ltd.) was immersed in a pickup at 50% by mass (conditions in which the amount of the gas absorbent applied was 0.4% by mass × 50% by mass = 0.2% by mass with respect to the cloth). The cloth after the immersion treatment was dried at 160 ° C. for 2 minutes to obtain a gas adsorption material.

(Example 2)
A reaction solution obtained by adding 67 g of γ-aminopropylmethyldimethoxysilane to 437 g of colloidal silica (Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle size 10 to 20 nm, silica content 30% by mass) For about 2 hours. Next, carbon dioxide gas was blown into the reaction solution until the pH of the reaction solution reached 9, neutralization treatment was performed, 496 g of water was further added, and water dispersion with a gas adsorbent concentration of 20 mass% was added. A liquid was obtained. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Example 3)
A reaction solution obtained by adding 67 g of γ-aminopropylmethyldimethoxysilane to 665 g of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex 20L”, average particle size 50 nm, silica content 20 mass%) at room temperature Stir for about 2 hours. Next, formic acid is added to the reaction solution until the pH of the reaction solution reaches 9, neutralization treatment is performed, and then 268 g of water is further added to form an aqueous dispersion in which the concentration of the gas adsorbent is 20% by mass. Got. The pH of the reaction solution before neutralization was 11.4.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

Example 4
The aqueous dispersion obtained in the same manner as in Example 1 was diluted 50 times to prepare a 0.4 mass% gas adsorbent aqueous dispersion (treatment liquid). (Made by Color Dyeing Co., Ltd.) was dipped with a pickup of 50 mass%. And the gas-adsorbing material was obtained by air-drying the cloth after the immersion treatment at room temperature for one day and night.

(Example 5)
To 665 g of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex PS-S”, average particle size 100 nm, silica content 20 mass%), 67 g of γ- (2-aminoethyl) aminopropyltrimethoxysilane The added reaction solution was stirred at room temperature for about 2 hours. Next, after carbon dioxide gas was blown into the reaction solution until the pH of the reaction solution reached 9, neutralization was performed, and then 268 g of water was further added to disperse the water in which the concentration of the gas adsorbent was 20% by mass. A liquid was obtained. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Example 6)
300 g of water was added to 133 g of silica (trade name “E-220A” manufactured by Tosoh Silica Co., Ltd., particle size of about 1 μm) and stirred, and then 67 g of γ- (2-aminoethyl) aminopropyltrimethoxysilane was added thereto. The reaction solution to which was added was stirred at room temperature for about 2 hours. Next, the reaction solution was neutralized by adding formic acid until the pH of the reaction solution reached 9. The pH of the reaction solution before neutralization was 11. 10% by mass of “cellopol PC-300” (trade name, manufactured by Sanyo Kasei Co., Ltd.) 15 g, “road pole 23” (trade name, manufactured by Rhodia Nikka Co., Ltd.) as a dispersant in the reaction solution after the neutralization treatment. Add 20 g of aqueous solution and 10 g of “Softanol 120” (trade name, manufactured by Nippon Shokubai Co., Ltd.) and 455 g of water, and stir them thoroughly to obtain an aqueous dispersion having a gas adsorbent concentration of 20% by mass. Obtained.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Example 7)
To 437 g of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle size 10-20 nm, silica content 30% by mass), 67 g of γ- (2-aminoethyl) aminopropylmethyldimethoxysilane was added. The added reaction solution was stirred at room temperature for about 2 hours. Next, carbon dioxide gas was blown into the reaction solution until the pH of the reaction solution reached 9, neutralization treatment was performed, 496 g of water was further added, and water dispersion with a gas adsorbent concentration of 20 mass% was added. A liquid was obtained. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Example 8)
To 437 g of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle size 10-20 nm, silica content 30 mass%), 67 g of γ- (2-aminoethyl) aminopropyldimethylmethoxysilane was added. The added reaction solution was stirred at room temperature for about 2 hours. Next, carbon dioxide gas was blown into the reaction solution until the pH of the reaction solution reached 9, neutralization treatment was performed, 496 g of water was further added, and water dispersion with a gas adsorbent concentration of 20 mass% was added. A liquid was obtained. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

Example 9
A reaction solution obtained by adding 67 g of γ-aminopropyltrimethoxysilane to 437 g of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle diameter 10 to 20 nm, silica content 30% by mass), Stir at room temperature for about 2 hours. Next, carbon dioxide gas was blown into the reaction solution until the pH of the reaction solution reached 9, neutralization treatment was performed, 496 g of water was further added, and water dispersion with a gas adsorbent concentration of 20 mass% was added. A liquid was obtained. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Example 10)
A reaction solution obtained by adding 67 g of γ-aminopropyltrimethoxysilane to 665 g of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex O”, average particle size 10 to 20 nm, silica content 20 mass%), Stir at room temperature for about 2 hours. Next, carbon dioxide gas was blown into the reaction solution until the pH of the reaction solution reached 6, neutralization treatment was performed, and then 268 g of water was further added to disperse the water in which the concentration of the gas adsorbent was 20% by mass. A liquid was obtained. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Comparative Example 1)
Addition of 67 g of γ- (2-aminoethyl) aminopropyltrimethoxysilane to 437 g of colloidal silica (Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle size 10-20 nm, silica content 30% by mass) The reaction solution was stirred at room temperature for about 2 hours, and then 496 g of water was further added to obtain an aqueous dispersion having a gas adsorbent concentration of 20% by mass.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Comparative Example 2)
Addition of 67 g of γ- (2-aminoethyl) aminopropyltrimethoxysilane to 437 g of colloidal silica (Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle size 10-20 nm, silica content 30% by mass) The reaction solution was stirred at room temperature for about 2 hours. Next, the reaction solution is neutralized by adding hydrochloric acid until the pH of the reaction solution reaches 9, and then 496 g of water is further added to the aqueous dispersion in which the concentration of the gas adsorbent is 20% by mass. Got. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Comparative Example 3)
Addition of 67 g of γ- (2-aminoethyl) aminopropyltrimethoxysilane to 437 g of colloidal silica (Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle size 10-20 nm, silica content 30% by mass) The reaction solution was stirred at room temperature for about 2 hours. Next, citric acid is added to the reaction solution until the pH of the reaction solution becomes 9, neutralization treatment is performed, 496 g of water is further added, and water dispersion in which the concentration of the gas adsorbent is 20% by mass is added. A liquid was obtained. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Comparative Example 4)
300 g of water was added to 133 g of silica (trade name “E-220A” manufactured by Tosoh Silica Co., Ltd., particle size of about 1 μm) and stirred, and then 67 g of γ- (2-aminoethyl) aminopropyltrimethoxysilane was added thereto. The reaction solution to which was added was stirred at room temperature for about 2 hours. Next, a 10% by mass aqueous solution of “cellopol PC-300” (trade name, manufactured by Sanyo Kasei Co., Ltd.) 15 g and “load pole 23” (trade name, manufactured by Rhodia Nikka Co., Ltd.) as a dispersant is added to the reaction solution. And 10 g of “Softanol 120” (trade name, manufactured by Nippon Shokubai Co., Ltd.) and 455 g of water are sufficiently stirred to obtain an aqueous dispersion having a gas adsorbent concentration of 20% by mass. It was.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Comparative Example 5)
To 437 g of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle size 10-20 nm, silica content 30 mass%), 67 g of γ- (2-aminoethyl) aminopropylmethyldimethoxysilane was added. The added reaction solution was stirred at room temperature for about 2 hours. Next, the reaction solution was neutralized with hydrochloric acid until the pH of the reaction solution reached 9, and then 496 g of water was further added to obtain an aqueous dispersion having a gas adsorbent concentration of 20% by mass. It was. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Comparative Example 6)
To 437 g of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle size 10-20 nm, silica content 30 mass%), 67 g of γ- (2-aminoethyl) aminopropylmethyldimethoxysilane was added. The added reaction solution was stirred at room temperature for about 2 hours. Next, this reaction solution is neutralized with citric acid until the pH of the reaction solution reaches 9, and then 496 g of water is further added to form an aqueous dispersion having a gas adsorbent concentration of 20% by mass. Obtained. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Comparative Example 7)
To 437 g of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle size 10-20 nm, silica content 30 mass%), 67 g of γ- (2-aminoethyl) aminopropyldimethylmethoxysilane was added. The added reaction solution was stirred at room temperature for about 2 hours. Next, the reaction solution was neutralized with hydrochloric acid until the pH of the reaction solution reached 9, and then 496 g of water was further added to obtain an aqueous dispersion having a gas adsorbent concentration of 20% by mass. It was. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Comparative Example 8)
A reaction solution obtained by adding 67 g of γ-aminopropyltrimethoxysilane to 437 g of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex 30”, average particle diameter 10 to 20 nm, silica content 30% by mass), Stir at room temperature for about 2 hours. Next, the reaction solution was neutralized with hydrochloric acid until the pH of the reaction solution reached 9, and then 496 g of water was further added to obtain an aqueous dispersion having a gas adsorbent concentration of 20% by mass. It was. The pH of the reaction solution before neutralization was 11.6.

  Next, a gas adsorption material was obtained in the same manner as in Example 1 except that the aqueous dispersion obtained above was used.

(Reference Example 1)
The aqueous dispersion obtained in the same manner as in Comparative Example 1 was diluted 50 times to prepare a 0.4 mass% gas adsorbent aqueous dispersion (treatment liquid). (Made by Color Dyeing Co., Ltd.) was dipped with a pickup of 50% by mass. And the gas-adsorbing material was obtained by air-drying the cloth after the immersion treatment at room temperature for one day and night.

[Evaluation of sprayability of gas adsorbent]
About the water dispersion liquid of the gas adsorbent obtained by the Example and the comparative example, the spray processing aptitude was evaluated by the following method. The results are shown in Table 1.

50 mL of a gas adsorbent aqueous dispersion having a gas adsorbent concentration of 20% by mass is placed in a hand spray bottle (trade name “Spray Pump Z-305-101”, manufactured by Mitani Valve Co., Ltd.) The spraying operation was repeated until there was no more. From the degree of clogging of the spray at this time, the suitability for spray processing was determined in three stages based on the following criteria.
○: The resistance does not change between the beginning and the end of the test, and all the gas adsorbent can be sprayed.
(Triangle | delta): Although resistance when taking out gas adsorbent from a spray increases gradually, all gas adsorbent can be taken out.
X: The spray is clogged, and all the gas adsorbent cannot be taken out.

[Evaluation of gas adsorption material]
About the gas adsorption material obtained by said Example and comparative example, gas adsorption property and hue were evaluated with the following method. The results are shown in Table 2.

(Gas adsorption)
The gas adsorbing material obtained was cut into a size of 10 cm × 10 cm (100 cm ² ) into a 5 L Tedlar bag, sealed, and the air inside was completely removed with an aspirator. In this, 3 L of nitrogen gas containing an initial concentration of acetic acid of 50 ppm or an initial concentration of acetaldehyde of 20 ppm was sealed, the concentration of acetic acid or acetaldehyde after standing at room temperature for 2 hours was measured, and the reduction rate was obtained by the following formula. .

(Hue)
The hue of the gas adsorbing material was visually determined in three stages based on the following criteria.
○: The color tone is the same as that of an unprocessed 100% polyester black dyed cloth.
Δ: Spots and white powder are not seen, but the entire surface of the material looks slightly whitish.
X: White spots are seen on the material surface, or white powder is seen.

  As shown in Table 2, the gas adsorbing material of Example 1 manufactured using a gas adsorbent obtained by neutralizing an amino group derived from an organosilicon compound supported on silica with carbonic acid, It was confirmed that the gas adsorbability with respect to acetic acid and acetaldehyde was maintained at the same level as in the case without heat treatment (Example 4) in spite of being subjected to heat treatment. Further, the gas adsorbing materials of Examples 2 to 10 produced using a gas adsorbent obtained by neutralizing an amino group derived from an organosilicon compound supported on silica with carbonic acid or formic acid are also used for acetic acid and acetaldehyde. It was confirmed that the gas adsorption property was sufficient.

  On the other hand, the gas adsorbing material of Comparative Example 1 manufactured using a gas adsorbent that does not neutralize the amino group derived from the organosilicon compound supported on silica is subjected to heat treatment in the manufacturing process. It can be seen that the gas adsorbability with respect to acetic acid and acetaldehyde is considerably reduced as compared with the case without heat treatment (Reference Example 1). It can also be seen that Comparative Examples 2, 5, 7, and 8 in which the amino group was neutralized with hydrochloric acid and Comparative Examples 3 and 6 in which the amino group was neutralized with citric acid also show low gas adsorbability to acetic acid and acetaldehyde.

(Example 11)
The aqueous dispersion obtained in the same manner as in Example 1 was diluted 10 times to prepare a 2 mass% gas adsorbent aqueous dispersion (treatment liquid). ) (Made by Color Dyeing Co., Ltd.) was immersed in a pickup at 50% by mass (conditions in which the amount of the gas absorbent applied was 2% by mass × 50% by mass = 1% by mass). The cloth after the immersion treatment was dried at 160 ° C. for 2 minutes to obtain a gas adsorption material.

Example 12
A gas adsorbing material was obtained in the same manner as in Example 11 except that the aqueous dispersion obtained in the same manner as in Example 5 was used.

(Example 13)
A gas adsorbing material was obtained in the same manner as in Example 11 except that the aqueous dispersion obtained in the same manner as in Example 6 was used.

(Example 14)
A gas adsorbing material was obtained in the same manner as in Example 11 except that the aqueous dispersion obtained in the same manner as in Example 7 was used.

(Comparative Example 9)
A gas adsorbing material was obtained in the same manner as in Example 11 except that the aqueous dispersion obtained in the same manner as in Comparative Example 4 was used.

  The hues of the gas adsorbing materials obtained in Examples 11 to 14 and Comparative Example 9 were evaluated by the above method. The results are shown in Table 3 together with the results of Examples 1, 5, 6 and 7, and Comparative Example 4.

  As shown in Table 3, it was found that the gas adsorbents of Examples 1, 5, 6 and 7 had almost no influence on the hue of the substrate even if the amount of adhesion to the substrate was increased. On the other hand, it can be seen that the gas adsorbent of Comparative Example 4 has a greater change in the hue of the base material when the amount of adhesion is large, and is inferior in practicality when used as an interior material.

  As described above, the gas adsorbent according to the present invention can exhibit excellent gas adsorbability even when heat treatment is performed in the production process of the gas adsorbing material. In addition, the conventional gas adsorbent like the comparative example 1 can exhibit sufficient gas adsorbability, if heat processing is not added at the time of manufacture of a gas adsorption raw material. However, usually, when various materials are processed using an aqueous dispersion of a gas adsorbent, it is indispensable to evaporate water by heat treatment or the like in order to speed up the process. On the other hand, according to the gas adsorbent according to the present invention having excellent heat resistance, a gas adsorbing material having excellent gas adsorbability can be efficiently produced.

  According to the present invention, the adsorption performance of aldehyde-based malodorous gases such as formaldehyde and acetaldehyde, and acidic malodorous gases typified by organic acids such as acetic acid and butyric acid is sufficiently excellent, and the gas adsorption performance is reduced by heat. It is possible to provide a gas adsorbent that can be made smaller. In addition, according to the present invention, it is possible to provide a gas adsorbing material capable of maintaining higher adsorption performance for the malodorous gas than in the past even when subjected to heat treatment or thermal history over time. .

In addition, according to the gas adsorption material of the present invention, it is possible to sufficiently suppress a decrease in gas adsorption performance even when the material is subjected to heat treatment or heat history over time during production or processing. Performance or workability and gas adsorption performance can be achieved at a higher level than before. The gas adsorbing material of the present invention can be used for interior and exterior materials such as wallpaper, curtains and carpets, interior materials for vehicles such as car seats and ceiling materials, including filters for air cleaners for home use or vehicles. Adsorption and removal of acid-based gas and aldehyde-based gas can be achieved at a higher reduction rate than before.

Claims (5)

  An organosilicon compound having an amino group and / or imino group is supported on a carrier, and a part or all of the amino group and / or imino group is at least one acid selected from the group consisting of carbonic acid, formic acid and acetic acid. A gas adsorbent obtained by neutralization.   The gas adsorbent according to claim 1, wherein the carrier is activated carbon or a metal oxide having a hydroxyl group.   The gas adsorbent according to claim 2, wherein the metal oxide is silica.   The gas adsorbent according to any one of claims 1 to 3, wherein the carrier has an average particle diameter of 1 nm to 5 µm. The gas adsorption material formed by providing the gas adsorbent as described in any one of Claims 1-4 to a base material.