JP5083487B2 - Removal method of harmful substances generated from direct methanol fuel cell - Google Patents

Description

  The present invention relates to a method for suppressing a harmful substance that may be generated from a fuel cell using organic matter as a fuel from being discharged out of the system and maintaining a favorable environment in which the fuel cell is used.

A solid polymer electrolyte fuel cell has a solid electrolyte membrane such as a perfluorosulfonic acid membrane as an electrolyte, and a fuel electrode and an oxidant electrode are joined to both sides of the membrane. Hydrogen or methanol is used for the anode and oxygen is used for the cathode. Is a device that generates electricity through an electrochemical reaction. The electrochemical reaction that occurs at each electrode is as follows:
CH ₃ OH + H ₂ O → 6H ⁺ + CO ₂ + 6e ⁻ [1]
And at the cathode,
3/2 O ₂ + 6H ⁺ + 6e ⁻ → 3H ₂ O [2]
It is. In order to cause this reaction, both electrodes are composed of a mixture of carbon fine particles carrying a catalyst material and a solid polymer electrolyte.

  In such a solid polymer electrolyte fuel cell, when methanol is used as the fuel, the methanol supplied to the anode reaches the catalyst through the pores in the electrode, and the methanol is decomposed by the catalyst. Electrons and hydrogen ions are generated by the reaction of reaction formula [1]. The hydrogen ions reach the cathode through the electrolyte in the anode and the solid electrolyte membrane between the electrodes, react with oxygen supplied to the cathode and electrons flowing from the external circuit, and water is formed as in the above reaction formula [2]. Arise. On the other hand, electrons emitted from methanol are led to the external circuit through the catalyst carrier in the anode, and flow into the cathode from the external circuit. As a result, in the external circuit, electrons flow from the anode to the cathode and electric power is taken out.

  This direct methanol fuel cell using methanol as a fuel has a high possibility of being applicable as a small fuel cell for portable devices, and in recent years, development has become active as a next-generation secondary battery such as a portable computer or a cellular phone. .

  However, in fuel cells that use organic substances such as direct methanol as the direct fuel, all fuel components ideally release hydrogen and carbon dioxide, but side reactions and incomplete reactions due to contamination with impurities, etc. To produce an intermediate organic substance, carbon monoxide, and the like. As a result of various studies, it has been clarified that some of these may have harmful effects on the living body (toxic substances) [Kazuhide Totsuka, Automotive Research, 24 (2), p. . 59-62 (2002)]. According to these studies, for example, it is known that formic acid, formaldehyde, methyl formate, carbon monoxide and the like are produced from a direct methanol fuel cell. Since some of these by-products are discharged out of the fuel cell system as fuel cell exhaust gas, there is a concern that the working environment may deteriorate when the fuel cell is used in a closed space such as an office. For this reason, there has been a demand for a system capable of suppressing the discharge of these harmful substances into the external environment even when a solid polymer fuel cell is used.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for capturing harmful substances generated from a fuel cell and suppressing the discharge thereof.

A method for removing harmful substances generated from a fuel cell according to the present invention is a method for removing harmful substances generated from a fuel cell, comprising: a solid substance capable of adsorbing and / or including the harmful substances; It is characterized by being captured by contact and suppressing release of the harmful substance to the environment surrounding the fuel cell ( Invention 1). Thereby, the safety | security of a fuel cell can be improved.

The method of the present invention can be suitably applied to a solid polymer fuel cell, particularly a direct methanol fuel cell ( Inventions 2 and 3).

Moreover, the method for removing harmful substances generated from the fuel cell of the present invention is particularly suitable for portable small fuel cells ( Invention 4). Since portable small fuel cells are often used in a small room or the like, the concentration of harmful substances may increase. Therefore, it is necessary to suppress the discharge, which is excellent in this respect.

The fuel for the fuel cell is preferably one or more selected from the group consisting of alcohols, ethers, hydrocarbons and acetals ( Invention 5).

Further, the solid substance capable of adsorbing and / or inclusion of the harmful substance is a molecular compound containing a fuel for a fuel cell ( Invention 6). In particular, this molecular compound is formed from the fuel for a fuel cell and a host compound. It is preferable that it is an inclusion compound ( Invention 7). The solid substance capable of adsorbing and / or including these harmful substances may be a mixture of a molecular compound containing fuel for fuel cells and a solid substance not containing fuel for fuel cells ( Invention 8). The same kind of clathrate compound containing fuel for fuel cells can be diverted for capturing harmful substances, and the fuel cell system can be simplified. In addition, when a harmful substance cannot be sufficiently removed by using only a molecular compound containing a fuel for a fuel cell, a solid substance having excellent adsorption performance such as activated carbon may be used in combination.

  According to the present invention, harmful substances generated from a fuel cell can be easily removed, and the safety of the fuel cell can be improved. Such a method of the present invention is often used in a small room or the like, and is particularly suitable for small fuel cells such as portable devices in which the concentration of harmful substances tends to be high.

Hereinafter, a method for removing harmful substances generated from the fuel cell of the present invention will be described in detail.
The form of the fuel cell according to the present invention is not particularly limited, but is preferably a solid polymer electrolyte fuel cell, including a direct methanol fuel cell.

  The fuel for the fuel cell according to the present invention may be any fuel that can be used as a fuel for the fuel cell, and examples thereof include hydrogen, alcohols, ethers, hydrocarbons, acetals, and the like. It is not limited. More specifically, examples of the fuel material include alcohols such as hydrogen, methanol, ethanol, n-propanol, isopropanol, and ethylene glycol; ethers such as dimethyl ether, methyl ethyl ether, and diethyl ether; hydrocarbons such as propane and butane. Acetals such as dimethoxymethane and trimethoxymethane, and the like may be used singly or as a mixture of two or more.

  The present invention basically captures a harmful substance generated from a fuel cell by bringing the harmful substance into contact with the solid substance capable of adsorbing and / or inclusion, and releases the harmful substance to the environment surrounding the fuel cell. It suppresses.

  In the present invention, as a solid substance capable of adsorbing harmful substances, activated carbon, calcium oxide, zeolite, titanium oxide, graphite, alumina, transition metal dicardogenite, lanthanum fluoride, clay mineral (montmorillonite, etc.), silver salt, silicate General-purpose adsorption materials such as phosphate, zeolite, silica, and porous glass can be used. For the purpose of removing acidic substances such as organic acids, alkaline solids (calcium oxide, basic magnesium carbonate, chitosan, etc.) can also be used.

  In addition, a fuel composition for a fuel cell such as a solid molecular compound that can take in fuel for fuel cell such as methanol, which will be described later, adsorbs or encapsulates harmful substances after releasing methanol as a fuel. It has the property of being captured by an action such as contact. Therefore, this fuel composition may be applied as a solid substance for removing harmful substances, so that fuel cell fuel supply and harmful substance removal can be performed simultaneously. Further, the harmful substance removability can be improved by mixing and using the above-mentioned general adsorbing material and a solid substance incorporating the fuel for the fuel cell.

Hereinafter, embodiments of the method of the present invention will be described with reference to the drawings.
[First Reference Form]
Figure 1 is a longitudinal sectional view of the applicable fuel cell systems the instructions for removing harmful substances generated from the fuel cell according to the first referential embodiment of the present invention.

  In FIG. 1, the fuel cell system 1 includes a fuel electrode 3 and an air electrode 4 that are electrically connected to each other by an external circuit A on both sides of an electrolyte membrane 2. It is connected to the fuel electrode 3 and is detachable. On the other hand, an oxidant flow path 6 is provided in the air electrode 4 so as to be connected to the air electrode 4. The fuel flow path 5 is filled with a solid substance (hereinafter referred to as a harmful substance capturing body) 7 capable of adsorbing or enclosing a harmful substance, and a fuel supply part 8 on one side and a discharge part 9 on the other side, respectively. Is provided. In addition, an air or oxygen suction part 10 and a discharge part 11 are provided on one side of the oxidant flow path 6.

In the fuel cell system 1 having such a structure, when a methanol aqueous solution (methanol + H ₂ O) is supplied from the fuel supply unit 8, hydrogen ions (H ⁺ ), carbon dioxide (CO ₂ ), and electrons are generated by the catalyst component of the fuel electrode 3. (E ⁻ ), electrons (e ⁻ ) are introduced from the external circuit A by electrical connection, and hydrogen ions (H ⁺ ) are introduced into the air electrode 4 by passing through the electrolyte membrane 2. CO ₂ , H ₂ O and unreacted methanol are discharged. On the other hand, in the air electrode 4, air or oxygen (O ₂ ) is supplied from the suction portion 10, and this oxygen (O ₂ ) reacts with hydrogen ions (H ⁺ ) and electrons (e ⁻ ) generated at the fuel electrode 3. Thus, water or oxygen (O ₂ ) and water (H ₂ O) that were not involved in the reaction are discharged from the discharge unit 11. In such a reaction, electrons flow from the fuel electrode 3 toward the air electrode 4 to extract electric power.

  However, the decomposition of methanol at the fuel electrode 3 does not necessarily proceed ideally, and harmful substances such as formic acid, formaldehyde, methyl formate, and carbon monoxide may be generated. Therefore, in this embodiment, by filling the fuel flow path 5 with the harmful substance capturing body 7, even if a harmful substance is generated, the fuel flow path 5 captures the harmful substance capturing body 7. These are suppressed from being discharged from the discharge portion 9.

[ First embodiment]
Next, a first embodiment of the present invention will be described with reference to FIG. Since this embodiment basically has the same configuration as the first reference embodiment described above, the same reference numeral is given to the same configuration, and detailed description thereof is omitted.

  In FIG. 2, the fuel flow path 5 has the same configuration as that of the first embodiment described above except that the methanol clathrate compound 12 which is a fuel composition containing fuel for fuel cells is filled.

In the fuel cell system 1 having such a structure, when water (H ₂ O) is supplied from the fuel supply unit 8, methanol is released by contact between the methanol clathrate compound 12 filled in the fuel flow path 5 and water. The methanol is converted into hydrogen ions (H ⁺ ), carbon dioxide (CO ₂ ), and electrons (e ⁻ ) by the catalyst component of the fuel electrode 3, and the electrons (e ⁻ ) are electrically connected from the external circuit A, Hydrogen ions (H ⁺ ) are introduced into the air electrode 4 by passing through the electrolyte membrane 2, and CO ₂ , H ₂ O and unreacted methanol are discharged from the discharge unit 9. On the other hand, in the air electrode 4, when air or oxygen (O ₂ ) is supplied from the suction portion 10, the oxygen (O ₂ ) is generated from hydrogen ions (H ⁺ ) and electrons (e ⁻ ) generated in the fuel electrode 3. Water is generated by the reaction, and air or oxygen (O ₂ ) and water (H ₂ O) that are not involved in the reaction are discharged from the discharge unit 11. In such a reaction, electrons flow from the fuel electrode 3 toward the air electrode 4 to extract electric power.

  However, the decomposition of methanol at the fuel electrode 3 does not necessarily proceed ideally, and harmful substances such as formic acid, formaldehyde, methyl formate, and carbon monoxide may be generated. Therefore, in the present embodiment, the methanol clathrate compound 12 is filled in the fuel flow path 5, so that even if harmful substances are generated, the clathrate compound 12 after the methanol is released in the fuel flow path 5 has the gap. These harmful substances are captured and the discharge of these harmful substances from the discharge unit 9 is suppressed. As described above, by using the methanol clathrate compound 12 which is a fuel composition containing fuel for fuel cells as the harmful substance capturing body, it is possible to simultaneously supply fuel and capture harmful substances. In this embodiment, the fuel flow path 5 is filled only with the methanol clathrate compound 12 which is a fuel composition, but it may be used by being mixed with the harmful substance capturing body 7 in the first embodiment. Alternatively, a host compound of an inclusion compound that does not include methanol may be mixed and used.

  In the above embodiment, the methanol clathrate compound 12 is used. However, since the fuel composition for a fuel cell similarly has the property of trapping by adsorbing or clathrating harmful substances after releasing the fuel, the same is applied. Can be applied. Examples of the fuel cell fuel composition include [1] a fuel cell fuel made of a molecular compound, and [2] a fuel cell fuel absorbed by a polymer. It is not limited to.

  Subsequently, the fuel compositions of the above [1] and [2], which are typical fuel compositions containing the fuel cell fuel according to the present invention, will be described.

[1] Molecular Compound of Fuel Cell Fuel and Opposite Compound The molecular compound referred to in the present invention is represented by two or more kinds of compounds that can exist stably alone, such as hydrogen bond and van der Waals force. These compounds are bonded by relatively weak interactions other than covalent bonds, and include hydrates, solvates, addition compounds, inclusion compounds, and the like. Such a molecular compound can be formed by a contact reaction between a partner compound that forms the molecular compound and a fuel for a fuel cell. For example, a gas or liquid fuel cell fuel is changed to a solid compound and compared. It is possible to store the fuel for the fuel cell stably and lightly.

  Examples of the molecular compound according to the present invention include an inclusion compound in which a fuel for a fuel cell is included by a contact reaction between a host compound and a fuel for a fuel cell.

  As a host compound that forms an inclusion compound that includes a fuel for a fuel cell, an organic compound, an inorganic compound, and an organic / inorganic composite compound are known. Multimolecular and high molecular weight hosts are known.

  Monomolecular host compounds include cyclodextrins, crown ethers, cryptands, cyclophanes, azacyclophanes, calixarenes, cyclotriveratrylenes, spherands, cyclic oligopeptides, etc. . Examples of the multi-molecular host compound include ureas, thioureas, deoxycholic acids, perhydrotriphenylenes, tri-o-thymotides, beansryls, spirobifluorenes, cyclophosphazenes, monoalcohols, Diols, acetylene alcohols, hydroxybenzophenones, phenols, bisphenols, trisphenols, tetrakisphenols, polyphenols, naphthols, bisnaphthols, diphenylmethanols, carboxylic acid amides, thioamides, bixanthenes, Examples thereof include carboxylic acids, imidazoles, and hydroquinones. In addition, examples of the polymer host compound include celluloses, starches, chitins, chitosans, polyvinyl alcohols, polyethylene glycol arm type polymers having 1,1,2,2-tetrakisphenylethane as a core, α, Examples include polyethylene glycol arm type polymers having α, α ′, α′-tetrakisphenylxylene as a core. In addition, an organophosphorus compound, an organosilicon compound, etc. are also mentioned.

  Examples of inorganic host compounds include titanium oxide, graphite, alumina, transition metal dicargogenite, lanthanum fluoride, clay minerals (such as montmorillonite), silver salts, silicates, phosphates, zeolites, silica, and porous glass. It is done.

  Furthermore, some organometallic compounds exhibit properties as host compounds. For example, organoaluminum compounds, organotitanium compounds, organoboron compounds, organozinc compounds, organoindium compounds, organogallium compounds, organotellurium compounds, organotins. Examples thereof include compounds, organic zirconium compounds, and organic magnesium compounds. Moreover, it is also possible to use a metal salt of an organic carboxylic acid, an organic metal complex, or the like, but it is not particularly limited as long as it is an organic metal compound.

  Of these host compounds, multi-molecular host compounds whose inclusion ability is hardly influenced by the molecular size of the guest compound are preferable.

Specific examples of the multimolecular host compound include urea, 1,1,6,6-tetraphenylhexa-2,4-diyne-1,6-diol, and 1,1-bis (2,4-dimethyl). Phenyl) -2-propyn-1-ol, 1,1,4,4-tetraphenyl-2-butyne-1,4-diol, 1,1,6,6-tetrakis (2,4-dimethylphenyl)- 2,4-hexadiyne-1,6-diol, 9,10-diphenyl-9,10-dihydroanthracene-9,10-diol, 9,10-bis (4-methylphenyl) -9,10-dihydroanthracene- 9,10-diol, 1,1,2,2-tetraphenylethane-1,2-diol, 4-methoxyphenol, 2,4-dihydroxybenzophenone, 4,4′-dihydroxybenzophenone, 2, 2'-dihydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-sulfonylbisphenol, 2,2'-methylenebis (4- Methyl-6-tert-butylphenol), 4,4′-ethylidenebisphenol, 4,4′-thiobis (3-methyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy) -5-t-butylphenyl) butane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethylene, 1,1,2, 2-tetrakis (3-methyl-4-hydroxyphenyl) ethane, 1,1,2,2-tetrakis (3-fluoro-4-hydroxyphenyl) Ethane, α, α, α ′, α′-tetrakis (4-hydroxyphenyl) -p-xylene, tetrakis (p-methoxyphenyl) ethylene, 3,6,3 ′, 6′-tetramethoxy-9,9 ′ -Bi-9H-xanthene, 3,6,3 ', 6'-tetraacetoxy-9,9'-bi-9H-xanthene, 3,6,3', 6'-tetrahydroxy-9,9'-bi -9H-xanthene, gallic acid, methyl gallate, catechin, bis-β-naphthol, α, α, α ′, α′-tetraphenyl-1,1′-biphenyl-2,2′-dimethanol, diphenic acid Bis (dicyclohexylamide), bis (dicyclohexylamide) fumarate, cholic acid, deoxycholic acid, 1,1,2,2-tetraphenylethane, tetrakis (p-iodophenyl) ethylene, 9,9′-bianthryl, 1 , 1, 2,2-tetrakis (4-carboxyphenyl) ethane, 1,1,2,2-tetrakis (3-carboxyphenyl) ethane, acetylenedicarboxylic acid, 2,4,5-triphenylimidazole, 1,2,4 5-tetraphenylimidazole, 2-phenylphenanthro [9,10-d] imidazole, 2- (o-cyanophenyl) phenanthro [9,10-d] imidazole, 2- (m-cyanophenyl) phenanthro [9] , 10-d] imidazole, 2- (p-cyanophenyl) phenanthro [9,10-d] imidazole, hydroquinone, 2-t-butylhydroquinone, 2,5-di-t-butylhydroquinone, 2,5-bis (2,4-dimethylphenyl) hydroquinone and the like.

  Among the compounds described above, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, 1,1,2,2-tetrakis (4 -Hydroxyphenyl) phenolic host compounds such as ethylene, amide host compounds such as diphenic acid bis (dicyclohexylamide), fumaric acid bis (dicyclohexylamide), 2- (m-cyanophenyl) phenanthro [9,10- d] An imidazole host compound such as imidazole is advantageous in terms of inclusion ability, and a phenol host compound such as 1,1-bis (4-hydroxyphenyl) cyclohexane is industrially easy to use. Is advantageous.

  These host compounds may be used individually by 1 type, and may use 2 or more types together. These host compounds may be any shape compounds as long as they form a solid clathrate compound with the fuel for the fuel cell.

  Of the host compounds described above, the organic host compound can also be used as an organic / inorganic composite material supported on an inorganic porous material. In this case, examples of the porous material supporting the organic host compound include intercalation compounds such as clay minerals and montmorillonites in addition to silicas, zeolites and activated carbons, but are not limited thereto. is not. Such an organic / inorganic composite material is prepared by dissolving the above-mentioned organic host compound in a solvent capable of dissolving it, impregnating the solution in a porous material, drying the solvent, drying under reduced pressure, etc. It can be manufactured by the method. The amount of the organic host compound supported on the porous material is not particularly limited, but is usually about 10 to 80% by mass with respect to the porous material.

  Examples of a method for synthesizing a fuel cell fuel clathrate compound using a host compound such as 1,1-bis (4-hydroxyphenyl) cyclohexane described above include direct contact between a fuel cell fuel and a host compound, The method of mixing is mentioned, By this, the inclusion compound which included the fuel for fuel cells can be synthesize | combined easily. Further, the clathrate compound can also be synthesized by heating and dissolving the host compound in the fuel cell fuel and then recrystallizing it. If the fuel for the fuel cell is a gas or a liquid, the clathrate compound can be obtained by bringing the fuel into contact with the host compound in a pressurized state.

  In the synthesis of the clathrate compound, the temperature at which the fuel for the fuel cell and the host compound are brought into contact with each other is not particularly limited, but is preferably from room temperature to about 100 ° C. There is no particular limitation on the pressure condition at this time. The time for contacting the fuel cell fuel with the host compound is not particularly limited, but is preferably about 0.01 to 24 hours from the viewpoint of work efficiency.

  The fuel for the fuel cell to be brought into contact with the host compound is preferably a high-purity fuel. However, when a host compound having the selective inclusion ability of the fuel for the fuel cell is used, the fuel for the fuel cell and other components are used. And a mixed liquid.

  The clathrate compound thus obtained varies depending on the type of the host compound used, the contact conditions with the fuel for the fuel cell, etc. An inclusion compound containing 10 moles.

  The clathrate compound thus obtained can stably store fuel for fuel cells over a long period of time in a normal temperature / normal pressure environment. Moreover, since this inclusion compound is lightweight, excellent in handleability, and can be made solid, it can be easily stored in a glass, metal, plastic or other container, and there is also a problem of liquid leakage. It will be resolved. Moreover, normally, the gaseous or liquid fuel cell fuel becomes solid by inclusion so that the properties as a deleterious substance or a dangerous substance can be avoided. Further, the chemical reactivity of the fuel for the fuel cell can be reduced, and for example, the corrosiveness to metals can be alleviated.

  The host compound after the fuel cell fuel is released from such an inclusion compound by the method described later has a selective inclusion ability with respect to the fuel cell fuel. It can be effectively reused.

[2] Fuel composition in which fuel cell fuel is absorbed in polymer This fuel composition is obtained by adding a liquid fuel cell fuel (hereinafter referred to as “liquid fuel”) to a crosslinked product (A) of the following polymer compound (1). Is absorbed (impregnated).

  Polymer compound (1): a polymer compound obtained by polymerizing or copolymerizing a structural unit having a carboxyl group and / or a sulfonic acid group in the molecule (hereinafter referred to as “acidic group-containing structural unit (a)”). In the polymer compound (2) having a content of the acidic group-containing structural unit (a) of 20 to 100% by mass, 30 to 100 mol% of protons of the carboxyl group and / or the sulfonic acid group Polymer compound substituted with onium cation

  As will be described later, in the present invention, the polymer compound (1) is produced by substituting a predetermined amount of protons of the carboxyl group and / or sulfonic acid group of the polymer compound (2) with an onium cation. The polymer compound (1) is not limited in any way, and the polymer compound (1) is produced by previously substituting the proton of the carboxyl group and / or sulfonic acid group of the acidic group-containing structural unit (a) with an onium cation, and then polymerizing or copolymerizing it. It may be what was done. Similarly, the crosslinked body (A) of the polymer compound (1) is not necessarily limited to a crosslinked polymer compound (1) produced in advance, and a crosslinked body of the polymer compound (1) can be obtained. As long as the polymer compound (2) or the polymer compound (1) is produced, crosslinking may be performed. The introduction and crosslinking of the onium cation may be performed in two or more stages.

  The acidic group-containing structural unit (a) constituting the polymer compound (2) includes a monomer having a carboxyl group [for example, (meth) acrylic acid, ethacrylic acid, crotonic acid, sorbic acid, maleic acid, itaconic acid , Fumaric acid, cinnamic acid, and anhydrides thereof]; monomers having a sulfonic acid group [for example, aliphatic vinyl sulfonic acid [vinyl sulfonic acid, allyl sulfonic acid, vinyl toluene sulfonic acid, styrene sulfonic acid, etc.], (Meth) acrylate type sulfonic acid [sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, etc.] and (meth) acrylamide type sulfonic acid [acrylamido-2-methylpropanesulfonic acid, etc.]. The carbon number of the acidic group-containing structural unit (a) is preferably 3-30.

  In the polymer compound (2), one kind of these acidic group-containing structural units (a) may be contained alone, or two or more kinds may be contained. Further, in the polymer compound (2), a structural unit that is copolymerizable with the acidic group-containing structural unit (a) other than the acidic group-containing structural unit (a) (hereinafter referred to as “other structural unit (b)”). May be included).

Other structural units (b) include, for example, alkyl (meth) acrylate (C 1-30) esters [methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth ) Butyl acrylate, ethyl hexyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, phenyl (meth) acrylate, octylphenyl (meth) acrylate, (meta Cyclohexyl acrylate, etc.]; oxyalkyl (meth) acrylate (1 to 4 carbon atoms) [hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, mono (polyethylene glycol) ester (meth) acrylate (PEG number average molecular weight: 100 to 4000), (meth) acrylic acid mono ( (Propylene glycol) ester (PPG number average molecular weight: 100 to 4000), (meth) acrylic acid monomethoxypolyethylene glycol (PEG number average molecular weight: 100 to 4000), (meth) acrylic acid monomethoxypropylene glycol (PPG number average molecular weight) : (100-4000) etc.]; (meth) acrylamides [(meth) acrylamide, (di) methyl (meth) acrylamide, (di) ethyl (meth) acrylamide, (di) propyl (meth) acrylamide etc.]]; allyl ether [Methyl allyl ether, ethyl allyl ether, propyl allyl ether, glycerol monoallyl ether, trimethylolpropane triallyl ether, pentaerythritol monoallyl ether, etc.]; α-olefins having 4 to 20 carbon atoms [ Isobutylene, 1-hexene, 1-octene, isooctene, 1-nonene, 1-decene, 1-dodecene, etc.]; aromatic vinyl compounds having 8 to 20 carbon atoms [styrene, t-butylstyrene, octylstyrene, etc.]; Other vinyl compounds [N-vinylacetamide, vinyl caproate, vinyl laurate, vinyl stearate, etc.]; amino group-containing monomers [dialkyl (alkyl carbon number: 1 to 5) aminoethyl (meth) acrylate, meta (acryloyl) ) Oxyethyltrialkyl (alkyl carbon number: 1 to 5) ammonium chloride, bromide or sulfate, etc.]; and alkali metal salts, primary to tertiary amine salts or alkanolamine salts of monomers having the carboxyl group or sulfonic acid group Can be mentioned. Also about these other structural units (b), 1 type may be contained independently in the high molecular compound (2), and 2 or more types may be contained.

  Content of the acidic group containing structural unit (a) in a high molecular compound (2) is 20-100 mass% normally, Preferably it is 40-100 mass%, More preferably, it is 60-100 mass%. When the content of the acidic group-containing structural unit (a) in the polymer compound (2) is less than 20%, even if the proton of a carboxyl group or a sulfonic acid group is replaced with an onium cation described later, it becomes a storage target. The amount of liquid fuel absorbed decreases, and the liquid fuel may not be gelled with a small amount.

  In the case where the polymer compound (2) contains another structural unit (b), among the above-mentioned exemplary structural units, from the viewpoint of the polymerizability of the monomer and the stability of the produced polymer, (meth) acrylic acid alkyl esters, Oxyalkyl (meth) acrylates, allyl ethers, α-olefins and aromatic vinyl compounds are preferred.

  In order to efficiently absorb and gel the liquid fuel, the difference in SP value between the liquid fuel and the other structural unit (b) is 5 or less in accordance with the SP value (solubility parameter) of the liquid fuel. It is preferable to select a liquid fuel because the amount of absorption and gelling power are likely to increase. The difference between the SP value of the liquid fuel to be absorbed and the SP value of the other structural unit (b) is selected to be 3 or less. More preferred.

  The method for producing the polymer compound (2) is not particularly limited as long as the polymer compound (2) containing a predetermined amount of the acidic group-containing structural unit (a) is finally obtained. In addition to the method of polymerizing a predetermined amount of the acidic group-containing structural unit (a), the polymer compound (2) is easily carboxylated such as an esterified product or amidated product of the carboxyl group- or sulfonic acid group-containing monomer. It can also be produced by polymerizing a monomer which can be changed into a group or a sulfonic acid group and introducing a predetermined amount of a structural unit of a carboxyl group or a sulfonic acid group into the molecule by a method such as hydrolysis. In addition, the polymer compound (2) may be a polysaccharide polymer containing carboxyl group and sulfonic acid group represented by carboxymethylcellulose, or a graft copolymer of the polysaccharide polymer and another monomer. There may be.

  The polymer compound (1) is obtained by replacing 30 to 100 mol% of the protons of the carboxyl group and / or sulfonic acid group of such a polymer compound (2) with an onium cation.

  Here, the onium cation is selected from the group of cations consisting of a quaternary ammonium cation (I), a tertiary phosphonium cation (II), a quaternary phosphonium cation (III), and a tertiary oxonium cation (IV). 1 type, or 2 or more types.

Examples of the quaternary ammonium cation (I) include the following (I-1) to (I-11).
(I-1) C4-C30 or higher aliphatic quaternary ammonium having an alkyl and / or alkenyl group; tetramethylammonium, ethyltrimethylammonium, diethyldimethylammonium, triethylmethylammonium, tetraethylammonium, trimethyl Propylammonium, tetrapropylammonium, butyltrimethylammonium, tetrabutylammonium, etc .;

  (I-2) Aromatic quaternary ammonium having 6 to 30 or more carbon atoms; trimethylphenylammonium, dimethylethylphenylammonium, triethylphenylammonium and the like;

  (I-3) C3-C30 or more alicyclic quaternary ammonium; N, N-dimethylpyrrinium, N-ethyl-N-methylpyrrolidinium, N, N-dimethylmorpholinium N, N-diethylmorpholinium, N, N-dimethylpiperidinium, N, N-diethylpiperidinium, etc .;

  (I-4) imidazolinium having 3 to 30 or more carbon atoms; 1,2,3-trimethylimidazolinium, 1,2,3,4-tetramethylimidazolinium, 1,3,4-trimethyl 2-ethylimidazolinium, 1,2-dimethyl-3,4-diethylimidazolinium, 1,2-dimethyl-3-ethylimidazolinium, 1-ethyl-3-methylimidazolinium, 1,2 , 3,4-tetraethylimidazolinium, 1,2,3-triethylimidazolinium, 4-cyano-1,2,3-trimethylimidazolinium, 2-cyanomethyl-1,3-dimethylimidazolinium, 4 -Acetyl-1,2,3-trimethylimidazolinium, 4-methylcarboxymethyl-1,2,3-trimethylimidazolinium, 4-formyl-1,2, - trimethyl imidazolinium, 3-hydroxyethyl-1,2,3-trimethyl imidazolinium, 1,2 3-hydroxyethyl dimethyl imidazolinium like;

  (I-5) imidazolium having 3 to 30 or more carbon atoms; 1,3-dimethylimidazolium, 1-ethyl-3-methylimidazolium, 1-methyl-3-ethylimidazolium, 1,2,3 , 4-tetramethylimidazolium, 1,2-dimethyl-3-ethylimidazolium, 1-ethyl-3-methylimidazolium, 1-methyl-3-ethylimidazolium, 1,2,3-triethylimidazolium, 1,2,3,4-tetraethylimidazolium, 1,3-dimethyl-2-phenylimidazolium, 1,3-dimethyl-2-benzylimidazolium, 4-cyano-1,2,3-trimethylimidazolium, 3-cyanomethyl-1,2-dimethylimidazolium, 4-acetyl-1,2,3-trimethylimidazolium, 4-methoxy- , 2,3-trimethylimidazolium, 3-formylmethyl-1,2-dimethylimidazolium, 2-hydroxyethyl-1,3-dimethylimidazolium, N, N'-dimethylbenzimidazolium, N, N'- Diethyl benzimidazolium, N-methyl-N′-ethyl benzimidazolium, etc .;

  (I-6) Tetrahydropyrimidinium having 4 to 30 or more carbon atoms; 1,3-dimethyltetrahydropyrimidinium, 1,2,3-trimethyltetrahydropyrimidinium, 1,2,3,4-tetra Methyltetrahydropyrimidinium, 8-methyl-1,8-diazabicyclo [5,4,0] -7-undecenium, 5-methyl-1,5-diazabicyclo [4,3,0] -5-nonenium, 3- Cyanomethyl-1,2-dimethyltetrahydropyrimidinium, 3-acetylmethyl-1,2-dimethyltetrahydropyrimidinium, 4-methylcarboxymethyl-1,2,3-trimethyl-tetrahydropyrimidinium, 3-methoxymethyl -1,2-dimethyltetrahydropyrimidinium, 4-hydroxymethyl-1,3-dimethyltetra Mud pyrimidinium and the like;

  (I-7) Dihydropyrimidinium having 4 to 30 or more carbon atoms; 1,3-dimethyl-2,4- or -2,6-dihydropyrimidinium [these are 1,3-dimethyl-2, This is expressed as 4, (6) -dihydropyrimidinium, and the same expression is used hereinafter. 1,2,3-trimethyl-2,4, (6) -dihydropyrimidinium, 1,2,3,4-tetramethyl-2,4, (6) -dihydropyrimidinium, 1,2 , 3,5-tetramethyl-2,4, (6) -dihydropyrimidinium, 8-methyl-1,8-diazacyclo [5,4,0] -7,9, (10) -undecandienium, 2-cyanomethyl-1,3-dimethyl-2,4, (6) -dihydropyrimidinium, 3-acetylmethyl-1,2-dimethyl-2,4, (6) -dihydropyrimidinium, 4-methyl Carboxymethyl-1,2,3-trimethyl-2,4, (6) -dihydropyrimidinium, 4-formyl-1,2,3-trimethyl-2,4, (6) -dihydropyrimidinium, 3 -Hydroxyethyl-1,2-dimethyl-2,4 (6) - dihydropyrimidinium like;

  (I-8) Guanidium having 3 to 30 or more carbon atoms having an imidazolinium skeleton; 2-dimethylamino-1,3,4-trimethylimidazolinium, 2-diethylamino-1,3,4-trimethylimidazole Linium, 2-dimethylamino-1-methyl-3,4-diethylimidazolinium, 2-dimethylamino-1,3-dimethylimidazolinium, 2-diethylamino-1,3-dimethylimidazolinium, 2- Diethylamino-1,3-diethylimidazolinium, 1,5,6,7-tetrahydro-1,2-dimethyl-2H-pyrimido [1,2a] imidazolinium, 1,5-dihydro-1,2-dimethyl -2H-pyrimido [1,2a] imidazolinium, 2-dimethylamino-3-methylcarboxymethyl-1-methylimidazo 2-dimethylamino-3-methoxymethyl-1-methylimidazolinium, 2-dimethylamino-3-hydroxyethyl-1-methylimidazolinium, 2-dimethylamino-4-hydroxymethyl-1,3- Dimethylimidazolinium, etc .;

  (I-9) Guanidium having 3 to 30 or more carbon atoms having an imidazolium skeleton; 2-dimethylamino-1,3,4-trimethylimidazolium, 2-diethylamino-1,3,4-trimethylimidazolium, 2-diethylamino-1,3-dimethyl-4-ethylimidazolium, 2-diethylamino-1,3,4-triethylimidazolium, 2-dimethylamino-1,3-dimethylimidazolium, 1,5,6,7 -Tetrahydro-1,2-dimethyl-2H-imide [1,2a] imidazolium, 1,5-dihydro-1,2-dimethyl-2H-pyrimido- [1,2a] imidazolium, 2-dimethylamino-3 -Cyanomethyl-1-methylimidazolium, 2-dimethylamino-4-methylcarboxymethyl-1,3-dimethyli Dazolium, 2-dimethylamino-3-methoxymethyl-1-methylimidazolium, 2-dimethylamino-3-formylmethyl-1-methylimidazolium, 2-dimethylamino-4-hydroxymethyl-1,3-dimethylimidazole Lithium, etc .;

  (I-10) C 4-30 or more guanidinium having a tetrahydropyrimidinium skeleton; 2-dimethylamino-1,3,4-trimethyltetrahydropyrimidinium, 2-diethylamino-1,3,4- Trimethyltetrahydropyrimidinium, 2-dimethylamino-1,3-dimethyltetrahydropyrimidinium, 2-diethylamino-1,3-dimethyltetrahydropyrimidinium, 1,3,4,6,7,8-hexahydro-1 , 2-dimethyl-2H-imide [1,2a] pyrimidinium, 1,3,4,6,7,8-hexahydro-1,2-dimethyl-2H-pyrimido [1,2a] pyrimidinium, 2-dimethylamino- 3-cyanomethyl-1-methyltetrahydropyrimidinium, 2-dimethylamino-4-acetyl-1 3-dimethyltetrahydropyrimidinium, 2-dimethylamino-4-methylcarboxymethyl-1,3-dimethyltetrahydropyrimidinium, 2-dimethylamino-3-methoxymethyl-1-methyltetrahydropyrimidinium, 2-dimethyl Amino-3-hydroxyethyl-1-methyltetrahydropyrimidinium, 2-dimethylamino-4-hydroxymethyl-1,3-dimethyltetrahydropyrimidinium, and the like;

  (I-11) Guanidium having 4 to 30 or more carbon atoms having a dihydropyrimidinium skeleton; 2-dimethylamino-1,3,4-trimethyl-2,4, (6) -dihydropyrimidinium, 2 -Diethylamino-1,3,4-trimethyl-2,4, (6) -dihydropyrimidinium, 2-diethylamino-1,3,4-triethyl-2,4, (6) -dihydropyrimidinium, 2 -Diethylamino-1,3-dimethyl-2,4, (6) -dihydropyrimidinium, 2-dimethylamino-1-ethyl-3-methyl-2,4, (6) -dihydropyrimidinium, 1, 6,7,8-tetrahydro-1,2-dimethyl-2H-imide [1,2a] pyrimidinium, 1,6-dihydro-1,2-dimethyl-2H-pyrimido [1,2a] pyrimidinium 2-Dimethylamino-4-cyano-1,3-dimethyl-2,4, (6) -dihydropyrimidinium, 2-dimethylamino-3-acetylmethyl-1-methyl-2,4, (6)- Dihydropyrimidinium, 2-dimethylamino-3-methylcarboxymethyl-1-methyl-2,4, (6) -dihydropyrimidinium, 2-dimethylamino-4-formyl-1,3-dimethyl-2, 4, (6) -dihydropyrimidinium, 2-dimethylamino-3-formylmethyl-1-methyl-2,4, (6) -dihydropyrimidinium, etc .;

Examples of the tertiary phosphonium cation (II) include the following (II-1) to (II-3).
(II-1) Aliphatic tertiary phosphonium having an alkyl and / or alkenyl group having 1 to 30 or more carbon atoms; trimethylphosphonium, triethylphosphonium, ethyldimethylphosphonium, diethylmethylphosphonium and the like;

  (II-2) Aromatic tertiary phosphonium having 6 to 30 or more carbon atoms; phenyldimethylphosphonium, phenylethylmethylphosphonium, phenylmethylbenzylphosphonium, etc .;

  (II-3) alicyclic tertiary phosphonium having 3 to 30 or more carbon atoms; methylthiolanium, phenylthiolanium, methylthianium, etc .;

Examples of the quaternary phosphonium cation (III) include the following (III-1) to (III-3).
(III-1) Aliphatic quaternary phosphonium having an alkyl and / or alkenyl group having 1 to 30 or more carbon atoms; tetramethylphosphonium, tetraethylphosphonium, tetrapropylphosphonium, tetrabutylphosphonium, methyltriethylphosphonium, methyl Tripropylphosphonium, methyltributylphosphonium, dimethyldiethylphosphonium, dimethyldibutylphosphonium, trimethylethylphosphonium, trimethylpropylphosphonium, trimethylbutylphosphonium, etc .;

  (III-2) Aromatic quaternary phosphonium having 6 to 30 or more carbon atoms; triphenylmethylphosphonium, diphenyldimethylphosphonium, triphenylbenzylphosphonium and the like;

  (III-3) alicyclic quaternary phosphonium having 3 to 30 or more carbon atoms; 1,1-dimethylphosphoranium, 1-methyl-1-ethylphosphonium, 1,1-diethylphosphonium, 1,1-diethyl phosphorinanium, 1,1-pentaethylene phosphorinanium, etc .;

Examples of the quaternary oxonium cation (IV) include the following (IV-1) to (IV-3).
(IV-1) Aliphatic tertiary oxonium having an alkyl and / or alkenyl group having 1 to 30 or more carbon atoms; trimethyloxonium, triethyloxonium, ethyldimethyloxonium, diethylmethyloxonium and the like;

  (IV-2) Aromatic tertiary oxonium having 6 to 30 or more carbon atoms; phenyldimethyloxonium, phenylethylmethyloxonium, phenylmethylbenzyloxonium, etc .;

  (IV-3) An alicyclic tertiary oxonium having 3 to 30 or more carbon atoms; methyl oxolanium, phenyl oxolanium, methyl oxonium and the like;

  Among these, a preferred onium cation is a quaternary ammonium cation (I), more preferred are the above (I-1), (I-4) and (I-5), and particularly preferred are ( I-4) and (I-5). These onium cations may be used alone or in combination of two or more.

  In the present invention, as a method for substituting the proton of the carboxyl group and / or sulfonic acid group of the polymer compound (2) with the onium cation, any method can be used as long as a predetermined amount of this proton can be replaced with the onium cation. However, for example, the above onium cation hydroxide salt (for example, tetraethylammonium hydroxide) or monomethyl carbonate salt (for example, 1,2,3,4-trimethylimidazolinium monomethyl carbonate) may be used. It can be easily replaced by adding to the polymer compound (2) and performing dehydration, decarboxylation or demethanol if necessary. Moreover, you may substitute similarly in the step of the monomer which comprises a high molecular compound (2).

  As a method for producing the polymer compound (1) by performing substitution with an onium cation, for example, polymerization is performed after the proton of the carboxyl group and / or the sulfonic acid group of the acidic group-containing structural unit (a) is substituted with an onium cation. Alternatively, a method of copolymerizing, a method of substituting the proton of the carboxyl group and / or the sulfonic acid group of the polymer compound (2) with an onium cation, etc. may be mentioned, but a polymer into which a predetermined amount of onium cation has been introduced. As long as the compound (1) is obtained, substitution of the proton of the carboxyl group and / or sulfonic acid group of the acidic group-containing structural unit (a) with the onium cation may be performed at any stage.

  The proportion (hereinafter referred to as “onium cation substitution rate”) of the proton of the carboxyl group and / or sulfonic acid group of the polymer compound (2) by an onium cation is usually 30 to 100 mol%, preferably 50 to 50%. It is 100 mol%, More preferably, it is 70-100 mol%. If the onium cation substitution rate is less than 30 mol%, the dissociation of the carboxyl group, sulfonic acid group and onium cation of the polymer compound (1) may be too low, and the swelling power and gelling power may be low.

  In the present invention, the polymer compound (1) is crosslinked by performing crosslinking in any of the above-described production process of the polymer compound (2), the production process of the polymer compound (1), or a subsequent process. It is assumed that the body (A). The crosslinking method may be a known method, and examples thereof include the following methods (1) to (5).

(1) Crosslinking with a copolymerizable crosslinking agent;
Of the acidic group-containing structural unit (a) and / or the onium cation-substituted product of the acidic group-containing structural unit (a), which is a raw material of the polymer compound (2), and other structural units (b) used as necessary A copolymerizable cross-linking agent that can be copolymerized with one or more types (hereinafter collectively referred to as “raw material components”) or has two or more double bonds in the molecule [for example, divinylbenzene, etc. Polyvalent vinyl type crosslinking agents, (meth) acrylamide type crosslinking agents such as N, N′-methylenebisacrylamide, polyvalent allyl ether type crosslinking agents such as pentaerythritol triallyl ether, and multivalents such as trimethylolpropane triacrylate ( (Meth) acrylic acid ester type cross-linking agent, etc.] is copolymerized with the raw material components and crosslinked before or during synthesis of the polymer compound (2).

(2) Cross-linking with a reactive cross-linking agent;
Reactive crosslinking agent having two or more functional groups capable of reacting with the functional group of the raw material component in the molecule [for example, polyisocyanate type crosslinking agent such as 4,4′-diphenylmethane diisocyanate, polyglycerol polyglycidyl ether, etc. Polyhydric epoxy type crosslinking agent, polyhydric alcohol type crosslinking agent such as glycerin, polyvalent amine / imine type crosslinking agent such as hexamethylenetetramine and polyethyleneimine, haloepoxy type crosslinking agent such as epichlorohydrin, and polyvalent metal salt such as aluminum sulfate And a crosslinking method before or during the synthesis of the polymer compound (2).

(3) Crosslinking with a polymerization reactive crosslinking agent;
Polymerization-reactive cross-linking agent having a functional group in the molecule that can be copolymerized with the raw material component or that has a double bond in the molecule and can react with the functional group of the raw material component [for example, glycidyl such as glycidyl methacrylate (Meth) acrylate type cross-linking agent, allyl epoxy type cross-linking agent such as allyl glycidyl ether, etc.], and a method of cross-linking before or during synthesis of the polymer compound (2).

(4) Cross-linking by irradiation;
A method of crosslinking the polymer compound (1) by irradiating the polymer compound (1) with radiation such as ultraviolet rays, electron beams, γ rays, or the like, or irradiating the raw material components with ultraviolet rays, electron beams, γ rays, etc. A method in which polymerization and crosslinking are simultaneously performed during the synthesis of the molecular compound (2).

(5) Crosslinking by heating;
The polymer compound (2) or the polymer compound (1) is heated to 100 ° C. or more and thermally crosslinked between the molecules of the polymer compound (2) or the polymer compound (1) [between carbon due to generation of radicals by heating. Or cross-linking between functional groups].

  Among these crosslinking methods, the preferred method varies depending on the use and form of the final product, but from a comprehensive aspect, (1) crosslinking with a copolymerizable crosslinking agent, (2) crosslinking with a reactive crosslinking agent, and (4) Cross-linking by radiation irradiation.

  Preferred among the copolymerizable crosslinking agents are polyvalent (meth) acrylamide type crosslinking agents, allyl ether type crosslinking agents, and polyvalent (meth) acrylic acid ester type crosslinking agents, and more preferred are: It is an allyl ether type crosslinking agent. Among the reactive crosslinking agents, preferred are a polyvalent isocyanate type crosslinking agent and a polyvalent epoxy type crosslinking agent, and more preferred are a polyvalent isocyanate type crosslinking agent having three or more functional groups in the molecule. Or a polyvalent epoxy type crosslinking agent.

  The degree of cross-linking can be appropriately selected depending on the purpose of use, but when a copolymerizable cross-linking agent is used, the addition amount is preferably 0.001 to 10% by mass with respect to all raw material components, and 0.01 to 5 More preferred is mass%.

  When a reactive crosslinking agent is used, the addition amount thereof varies depending on the shape of the crosslinked body (A), but is preferably 0.001 to 10% by mass with respect to all raw material components. In order to produce a good integrated gel containing liquid fuel, which will be described later, 0.01 to 5% by mass is particularly preferable with respect to all raw material components.

  In the present invention, a raw material component, that is, an acidic group-containing structural unit (a) and / or an onium cation-substituted product of the acidic group-containing structural unit (a), and a polymerization method of other structural unit (b) used as necessary are also known. Examples thereof include a solution polymerization method in a solvent in which each of the above monomers and the polymer to be formed dissolves, a bulk polymerization method in which polymerization is performed without using a solvent, and an emulsion polymerization method. Among these, the solution polymerization method is preferable.

  The solvent used in the case of solution polymerization can be appropriately selected depending on the solubility of the monomer and polymer to be used. For example, alcohols such as methanol and ethanol; carbonates such as ethylene carbonate, propylene carbonate and dimethyl carbonate; γ-butyrolactone Lactams such as ε-caprolactam; Ketones such as acetone and methyl ethyl ketone; Carboxylic acid esters such as ethyl acetate; Ethers such as tetrahydrofuran and dimethoxyethane; Aromatic hydrocarbons such as toluene and xylene The organic solvent, water, etc. can be mentioned. These solvents may be used alone or in combination of two or more.

  The polymerization concentration in the solution polymerization is not particularly limited and may vary depending on the intended use, but is preferably 1 to 80% by mass, and more preferably 5 to 60% by mass.

  The polymerization initiator may be a normal one, such as an azo initiator [azobisisobutyronitrile, azobiscyanovaleric acid, azobis (2,4-dimethylvaleronitrile), azobis (2-amidinopropane) dihydrochloride, azobis { 2-methyl-N- (2-hydroxyethyl) propionamide}, etc.], peroxide initiators [benzoyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, succinic acid peroxide, di ( 2-ethoxyethyl) peroxydicarbonate, hydrogen peroxide, etc.] and redox initiators [a combination of the above peroxide-based initiators and a reducing agent (ascorbic acid or persulfate), etc.].

  Examples of other polymerization methods include a method of adding a photosensitizer (such as benzophenone) and irradiating with ultraviolet rays, a method of irradiating with radiation such as γ rays and electron beams, and the like.

  The amount of initiator added when a polymerization initiator is used is not particularly limited, but is preferably 0.0001 to 5% by mass and 0.001 to 2% by mass based on the total weight of the raw material components used. Further preferred.

  The polymerization temperature also varies depending on the target molecular weight, the decomposition temperature of the initiator, the boiling point of the solvent used, etc., but is preferably -20 to 200 ° C, more preferably 0 to 100 ° C.

  Such a crosslinked body (A) has the ability to absorb liquid fuel, and absorbs liquid fuel to form a stable fuel composition.

  The amount of liquid fuel absorbed in the cross-linked body (A) varies depending on the type of the target fuel, the composition of the cross-linked body (A), the gel strength, and the like. It is preferable to design to ˜1000 (g-methanol / g-crosslinked body (A)), and more preferably to design to 50 to 900 (g-methanol / g-crosslinked body (A)). If this absorption amount is 10 (g-methanol / g-crosslinked product (A)) or more, the liquid retention amount is sufficient and the storage efficiency is excellent. If it is 1000 (g-methanol / g-crosslinked product (A)) or less, there is no problem that the gel strength of the fuel composition retaining the liquid fuel is too weak.

  When making the crosslinked body (A) which concerns on this invention into a particulate form, the particle diameter is 0.1-5000 micrometers in a volume average particle diameter, More preferably, it is 50-2000 micrometers. Moreover, it is preferable that the crosslinked body (A) particle | grains less than 0.1 micrometer are 10 mass% or less of the whole, and the crosslinked body (A) particle | grains exceeding 5000 micrometers are 10 mass% or less of the whole, and each is 5% or less. Is more preferable.

  The particle size was measured using a low-tap test sieve shaker and a standard sieve specified in JIS Z8801-2000, Perry's Chemical Engineers Handbook, 6th edition (MacGlow Hill Book Company, 1984). , P. 21) (hereinafter, the particle diameter is measured by this method).

  The method for making the crosslinked product (A) into a particulate form is not particularly limited as long as it finally becomes a particulate form, and examples thereof include the following methods (i) to (iv).

  (I) If necessary, using a solvent, the copolymerizable crosslinking agent is copolymerized to prepare a crosslinked product (A) of the polymer compound (1), and if necessary, the solvent is distilled off by a method such as drying, A method in which particles are pulverized using a known pulverization method.

  (Ii) If necessary, polymerize using a solvent to prepare the polymer compound (1), and then crosslink the polymer compound (1) by the reactive crosslinking agent or means such as irradiation, and if necessary, dry, etc. The method of distilling a solvent by the method of this, and grind | pulverizing using a well-known grinding | pulverization method, and making it a particulate form.

  (Iii) The acidic group-containing structural unit (a) and, if necessary, another structural unit (b) are copolymerized using a solvent in the presence of the copolymerizable cross-linking agent to crosslink to form a polymer. Then, after adding the onium cation compound and replacing the proton of the acidic group with a predetermined amount of onium cation, if necessary, the solvent is distilled off by a method such as drying, and pulverization is performed using a known pulverization method. how to.

  (Iv) An uncrosslinked polymer obtained by copolymerizing the acidic group-containing structural unit (a) and, if necessary, another structural unit (b) with a solvent as necessary in the presence of the copolymerizable crosslinking agent. Then, by performing irradiation with the onium cation compound and reactive crosslinking agent or radiation, the polymer is crosslinked at the same time as replacing the proton of the acidic group, and if necessary, the solvent is distilled off by a method such as drying, A method in which particles are pulverized using a known pulverization method.

  In the above method, the drying performed as necessary in the process of forming the crosslinked body (A) in the form of particles may be a known drying method, such as aeration drying (air circulation dryer or the like), air permeation drying (band type drying). Etc.), vacuum drying (vacuum dryer etc.), contact drying (drum dryer etc.) and the like.

  The drying temperature for drying is not particularly limited as long as the polymer or the like does not deteriorate or excessively cross-linked, but is preferably 0 to 200 ° C, more preferably 50 to 150 ° C.

  When the cross-linked body (A) is in the form of particles, the pulverization method may be a known method, for example, impact pulverization (pin mill, cutter mill, ball mill type pulverizer, high-speed rotation type pulverizer such as ACM pulverizer, etc.), Examples thereof include air pulverization (jet pulverizer, etc.), freeze pulverization, and the like.

  The fuel composition comprising the cross-linked product (A) and the fuel can be processed into various forms depending on the purpose, and the shape is not particularly limited, but preferred forms are particles, sheets, and integral gelation. Can be mentioned.

  Hereinafter, although the preparation method of a preferable form is demonstrated, since the preparation method etc., a preferable method, etc. differ a little with the form of a fuel composition, each is demonstrated.

  The particulate fuel composition may be one in which the particulate crosslinked body (A) has absorbed liquid fuel, or may have been particulate after absorbing liquid fuel. The method for forming particles may be the same as the method for producing the granular crosslinked body (A) described above, and the volume average particle diameter and the like are preferably the same values.

  When the fuel composition is formed into a sheet, examples of the sheet forming method include the following methods (v) to (vii).

  (V) A method in which the particulate crosslinked product (A) is sandwiched between a nonwoven fabric or paper to form a sandwich sheet, and then liquid fuel is absorbed.

  (Vi) After impregnating and / or applying a non-crosslinked body of the polymer compound (1) to a base material composed of one or more of nonwoven fabric, woven fabric, paper, and film, crosslinking with the crosslinking agent In addition, the polymer compound (1) is crosslinked using one or two or more crosslinking means selected from the group consisting of crosslinking by radiation irradiation and crosslinking by heating, and if necessary, the solvent is distilled off to form a sheet. A method of absorbing liquid fuel.

  (Vii) From 20 to 100% by mass of the acidic group-containing structural unit (a) in which 30 to 100 mol% of protons are substituted with the onium cation, from 0 to 80% by mass of the other structural unit (b), and from the crosslinking agent After the resulting mixed solution is impregnated and / or coated on a substrate composed of one or more of nonwoven fabric, woven fabric, paper and film, the substrate is added with a polymerization initiator and / or radiation, etc. A method of polymerizing using one or two or more cross-linking means selected from the group consisting of cross-linking by irradiation and cross-linking by heating, forming a sheet by distilling off the solvent if necessary, and then absorbing liquid fuel.

  Among these methods, (vi) or (vii) is preferable from the viewpoint of easy adjustment of the thickness of the prepared sheet and the absorption rate of the prepared sheet. When the shape is a sheet, the thickness of the fuel composition sheet is preferably 1 to 50000 μm, more preferably 5 to 30000 μm, and particularly preferably 10 to 10,000 μm. When the thickness of the sheet is 1 μm or more, the basis weight of the crosslinked body (A) is not too small, and when it is 50000 μm or less, the thickness of the sheet is not too thick. The sheet length and width can be appropriately selected depending on the size to be used, and are not particularly limited. However, the preferred length is 0.01 to 10 m, and the preferred width is 0.1 to 300 cm.

The basis weight of the cross-linked product (A) in the fuel composition sheet is not particularly limited, but the weight per unit area is determined by taking into account the absorption / holding capacity of the target liquid fuel and the thickness not being too thick. 10 to 3000 g / m ² is preferable, and 20 to 1000 g / m ² is more preferable.

In the present invention, a base material such as a nonwoven fabric, a woven fabric, paper, or a film that is used as necessary in order to form a sheet may be a known substrate, for example, a synthetic fiber having a basis weight of about 10 to 500 g / m ^2. Examples thereof include a nonwoven fabric or woven fabric made of natural fibers, paper (fine paper, thin paper, Japanese paper, etc.), a film made of a synthetic resin, and two or more substrates thereof and a composite thereof.

  Among these substrates, preferred are nonwoven fabrics or composites of nonwoven fabrics and plastic films or metal films, and particularly preferred are nonwoven fabrics, composites of nonwoven fabrics and plastic films.

  Although there is no limitation in particular about the thickness of these base materials, it is 1-50000 micrometers normally, Preferably it is 10-20000 micrometers. When the thickness is less than 1 μm, it is difficult to impregnate or apply a predetermined amount of the polymer compound (1). On the other hand, when the thickness exceeds 50000 μm, the sheet is too thick to provide a fuel composition containing fuel for fuel cells. Occasionally, the entire body becomes large and difficult to use.

  The coating method and impregnation method of the polymer compound (1) on the substrate may be a known method, and for example, a usual method such as coating or padding may be applied. After performing the coating and padding treatment, the solvent used for polymerization, dilution, viscosity adjustment and the like may be distilled off by a method such as drying, if necessary.

The amount of fuel absorbed (fuel content) in the sheet-shaped fuel composition is not particularly limited as long as the amount of fuel supply can be sufficiently ensured, but is 0.1 to 500 (g-fuel / cm ^2). - sheet) are preferred, 1 to 400 (g- fuel / cm ² - more preferably has a sheet). When the absorption amount is 0.1 (g-fuel / cm ² -sheet) or more, a sufficient amount of liquid fuel can be absorbed, and when it is 500 (g-fuel / cm ² -sheet) or less, the liquid fuel is reduced. The absorbed sheet is not too thick.

  The fuel composition according to the present invention may be an integral gelled fuel composition comprising the crosslinked body (A) and a liquid fuel. The ratio of the crosslinked body (A) / fuel in this integral gelled fuel composition is preferably 0.1 to 99/1 to 99.9% by mass, more preferably 0.5 to 50/50 to 99. 0.5 mass%, particularly preferably 1-30 / 70-99 mass%, most preferably 1-20 / 80-99 mass%. When the ratio of the crosslinked body (A) is 0.1% by mass or more, the gel strength of the produced fuel-containing gel may not be weak or the entire gel may not be gelled, whereas it is 99% by mass or less. In addition, since the content of the crosslinked body (A) is too large, the required amount of fuel added is too small, and there is no problem that a sufficient amount of fuel cannot be secured.

  Examples of a method for producing an integral gelled fuel composition include (viii) a method of adding a predetermined amount of fuel to the above-described particulate crosslinked body (A) of the present invention, and (ix) a crosslinked body (A). Although a method of adding fuel to the contained sheet may be used, these fuel-containing gels are preferably prepared by the methods listed in (x) and (xi) below.

  (X) The polymer compound (1) is dissolved in a liquid fuel, and the polymer compound (1) is integrated by crosslinking by any of crosslinking means such as crosslinking by the crosslinking agent, crosslinking by radiation irradiation, and crosslinking by heating. To make a gel.

  (Xi) 20-100 mass% of acidic group-containing structural unit (a) in which 30-100 mol% of protons are substituted with the onium cation in the liquid fuel, and 0-80 mass of other structural unit (b) if necessary % Is polymerized in the presence of the copolymerizable crosslinking agent to form an integrated gel.

  The form of the integrated gel fuel composition composed of the crosslinked body (A) and the liquid fuel can be selected as appropriate. Examples of the shape include a sheet shape, a block shape, a spherical shape, and a cylindrical shape. be able to. Among these, a preferable shape is a sheet shape, a block shape, or a column shape.

  1-50000 micrometers is preferable and, as for the thickness of the gel in the case of setting it as a sheet-like gel, 10-20000 micrometers is more preferable. What is necessary is just to select suitably about the width | variety and length of a sheet-like gel according to the use purpose, a place, a use, etc.

  There is no particular limitation on the method for producing an integral gelled fuel composition having a desired shape, for example, a method of gelling in a container or a cell according to the shape to be produced, a release paper, a film, a nonwoven fabric, etc. Further, there can be exemplified a method in which a gel is formed in the form of a sheet by laminating or coating a mixture of the polymer compound (1), raw material components and the like and a liquid fuel.

  Further, the fuel composition of this embodiment may contain other gelling agents (fatty acid soap, dibenzal sorbite, hydroxypropylcellulose, benzylidene sorbitol, carboxyvinyl polymer, polyethylene glycol, polyoxyalkylene, sorbitol, nitro as necessary. Cellulose, methylcellulose, ethylcellulose, acetylbutylcellulose, polyethylene, polypropylene, polystyrene, ABS resin, AB resin, acrylic resin, acetal resin, polycarbonate, nylon, phenol resin, phenoxy resin, urea resin, alkyd resin, polyester, epoxy resin, phthalate Acid diallyl resin, polyallomer, etc.), adsorbent (dextrin, dextran, silica gel, silica, alumina, molecular sieve, kaolin, diatom , Carbon black, activated carbon, etc.), a thickener, a binder, and fuel may be blended with one or more selected from the group consisting of substances which non-fluidized by chemical transformation. These are not particularly limited as long as they can exhibit their respective functions, and may be solid or liquid. Moreover, these can be mix | blended in the arbitrary steps which produce a fuel composition.

[3] Method of releasing fuel cell fuel from fuel composition In the present invention, the above-mentioned [1] fuel composition containing a molecular compound of fuel for fuel cell, or [2] fuel cell fuel absorbed in polymer When releasing the fuel cell fuel from the fuel composition such as the fuel composition, the fuel composition is brought into contact with water to elute the fuel cell fuel in the fuel composition to the water side to thereby remove the fuel. It can be taken out.

  In this case, the water may be an aqueous fuel cell fuel solution. Further, heating is not particularly required for the contact between the fuel composition and water, and it may be performed at room temperature, but it may be heated to about 50 to 150 ° C.

[ Second reference form]
Next, a second reference embodiment of the present invention will be described with reference to FIG. Since this reference embodiment basically has the same configuration as the first reference embodiment shown in FIG. 1, the same reference numerals are given to the same configuration, and detailed description thereof is omitted.

  In FIG. 3, the fuel flow path 5 is not filled with anything, and is filled with a solid substance (hereinafter referred to as a harmful substance trapping body) 7 that communicates with the discharge part 9 and can adsorb or contain the harmful substances. A similar configuration is provided except that the harmful substance capturing unit 13 is provided.

In the fuel cell system 1 having such a structure, when a methanol aqueous solution (methanol + H ₂ O) is supplied from the fuel supply unit 8, hydrogen ions (H ⁺ ), carbon dioxide (CO ₂ ), and electrons are generated by the catalyst component of the fuel electrode 3. (E ⁻ ), electrons (e ⁻ ) are introduced from the external circuit A by electrical connection, and hydrogen ions (H ⁺ ) are introduced into the air electrode 4 by passing through the electrolyte membrane 2. CO ₂ , H ₂ O and methanol are discharged. On the other hand, in the air electrode 4, when air or oxygen (O ₂ ) is supplied from the suction portion 10, the oxygen (O ₂ ) is generated from hydrogen ions (H ⁺ ) and electrons (e ⁻ ) generated in the fuel electrode 3. Water is generated by the reaction, and air or oxygen (O ₂ ) and water (H ₂ O) that are not involved in the reaction are discharged from the discharge unit 11. In such a reaction, electrons flow from the fuel electrode 3 toward the air electrode 4 to extract electric power.

  However, the decomposition of methanol at the fuel electrode 3 does not always proceed ideally, and harmful substances such as formic acid, formaldehyde, methyl formate and carbon monoxide may be generated. Therefore, in the present embodiment, by providing the hazardous substance capturing part 13 that is in communication with the discharge part 9 and filled with the harmful substance capturing body 7, even if a harmful substance is generated, the harmful substance is captured in the exhaust part 9. Since they are captured by the body 7, they are suppressed from being discharged from the discharge portion 9.

[ Third Reference Form]
Further, a third reference embodiment of the present invention will be described with reference to FIG. Since the present reference embodiment basically has the same configuration as the second reference embodiment described above, the same reference numeral is given to the same configuration, and detailed description thereof is omitted.

  In FIG. 4, there is further provided a harmful substance capturing part 14 that is in communication with the discharge part 11 on the air electrode 4 side and is filled with a solid substance (hereinafter referred to as a harmful substance capturing body) that can adsorb or contain harmful substances. It has the same configuration except that.

  Thus, by providing the harmful substance capturing part 14 in the discharge part 11 on the air electrode 4 side, the harmful substance generated at the air electrode 4 can also be captured and the discharge thereof can be suppressed.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not limited to the following examples at all, unless the summary is exceeded.

[ Reference Example 1]
In the direct methanol fuel cell system schematically shown in FIG. 3, the hazardous substance trap 13 is filled with calcium oxide (1.0 g), and a 3 mass% methanol aqueous solution is supplied from the fuel flow path 5 to the fuel electrode 3 as fuel. Was supplied at 0.1 mL / min. The aqueous methanol solution that passed through the fuel electrode 3 was discharged from the discharge section 9, and the gas contained in the discharged liquid was collected by a dry ice strap (-79 ° C., using methanol as a refrigerant). The air flow rate of the air electrode was set to 1.0 L / min.

  The motor was rotated with the fuel cell under the test conditions and operated for 24 hours. After the test, by-products in the gas collected in the dry ice strap were analyzed by gas chromatography (formaldehyde analysis) and high performance liquid chromatograph (formic acid analysis), neither formaldehyde nor formic acid was detected.

[Example 1 ]
In a direct methanol fuel cell system as schematically shown in FIG. 3, a methanol clathrate compound (host compound: 1,1-bis (4-hydroxyphenyl) cyclohexane) that clathrates about 10% by mass of methanol in the fuel flow path 5 ) 45 g was charged, and ion-exchanged water was supplied from the fuel flow path 5 to the fuel electrode 3 at 0.1 mL / min. The gas contained in the effluent was collected with a dry ice strap (−79 ° C., using methanol as the refrigerant). The air flow rate of the air electrode was set to 1.0 L / min.

  The motor was rotated with the fuel cell under the test conditions and operated for 24 hours. After the test, by-products in the gas collected in the dry ice strap were analyzed by gas chromatography (formaldehyde analysis) and high performance liquid chromatograph (formic acid analysis), neither formaldehyde nor formic acid was detected.

[ Reference Example 2 ]
The test was performed under the same conditions as in Reference Example 1 except that the harmful substance capturing part 13 was not filled with calcium oxide in Reference Example 1.

  The motor was rotated with the fuel cell under the test conditions and operated for 24 hours. After the test, by-products in the gas collected in the dry ice strap were analyzed by gas chromatograph (formaldehyde analysis) and high performance liquid chromatograph (formic acid analysis), and 0.3 mg formaldehyde and 0.7 mg formic acid were detected. It was done.

It is sectional drawing of the vertical direction of the fuel cell system which concerns on the 1st reference form to which the method of this invention is applied. It is sectional drawing of the vertical direction of the fuel cell system which concerns on 1st embodiment to which the method of this invention is applied. It is sectional drawing of the vertical direction of the fuel cell system which concerns on the 2nd reference form to which the method of this invention is applied. It is sectional drawing of the vertical direction of the fuel cell system which concerns on the 3rd reference form to which the method of this invention is applied.

Explanation of symbols

1 Fuel cell system 7 Solid substances that can adsorb toxic substances (harmful substance traps)
12 Methanol clathrate compound (fuel composition, hazardous substance trap)
2 Electrolyte membrane 3 Fuel electrode (anode)
4 Air electrode (cathode)

Claims (2)

A method for removing harmful substances generated by side reactions or incomplete reactions of methanol in a direct methanol fuel cell, including any of formic acid, formaldehyde, methyl formate and carbon monoxide,
The direct methanol fuel cell is provided with a fuel flow path for supplying methanol to the fuel electrode connected to the fuel electrode,
A solid inclusion compound formed from methanol and host compounds, the toxic substances by mixing the adsorbent and / or inclusion possible solid material was placed in the fuel flow path, wherein the clathrate compound with A harmful substance generated from a direct methanol fuel cell, wherein the harmful substance is captured by bringing the solid substance into contact with the harmful substance, and the release of the harmful substance to the environment surrounding the fuel cell is suppressed. How to remove material. The method for removing harmful substances generated from a direct methanol fuel cell according to claim 1 , wherein the direct methanol fuel cell is a small fuel cell for portable equipment.

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