JP2020098704A - Catalyst ink composition for bio fuel cell anode, anode for bio fuel cell, and bio fuel cell device - Google Patents

Abstract

To provide a catalyst ink composition for a bio fuel cell anode, a bio fuel cell anode, and a bio fuel cell device, a bio fuel cell being excellent in output and durability and further low in cost, and using a reductive organic matter as fuel.SOLUTION: A catalyst ink composition for a bio fuel cell anode, contains at least a conductive carbon material (A) and a nitrogen-containing heterocyclic compound (B), a bio fuel cell anode using a reductive organic matter as fuel. The catalyst ink composition for a bio fuel cell anode is characterized in that a mass ratio between the conductive carbon material (A) and the nitrogen-containing heterocyclic compound (B) is 5:95-99:1.SELECTED DRAWING: None

Description

The present invention relates to a catalyst ink composition for a biofuel cell anode, a biofuel cell anode, and a biofuel cell device.

With the spread of portable electronic devices such as mobile phones and laptop computers, and the advent of the IoT society in which all things are connected to the Internet and exchange information, the usage forms of power sources are becoming diverse. Presently, primary batteries and secondary batteries are mentioned as main portable power sources and are widely used in electronic devices. In addition, for small devices such as sensors, which are expected to be used in the future, utilization of fuel cells, solar power generation, etc. in addition to conventional batteries is being considered.

A biofuel cell, which has been developed in recent years, is a power generation device that uses electric energy generated by an enzymatic reaction or the like by using an organic substance such as sugar, alcohol, or organic acid as a fuel. Most of the oxidoreductases are used for the cathode and anode, and it is an energy system that uses a wide variety of organic substances and oxygen in the air as a fuel to generate electricity. It can be operated at room temperature, abundant organic energy sources can be utilized, The high safety is cited as an advantage (Patent Document 1). However, since further improvement of the output characteristics is required, a biofuel cell using an electrode in which an enzyme and a mediator are immobilized on carbon paper (Patent Document 2), carbon and/or an inorganic compound as a fuel, an enzyme, A biofuel cell using an electrode composed of an enzyme-immobilized compound such as a pyrene compound has also been reported (Patent Document 3).
On the other hand, studies have also been conducted on a biofuel cell that uses an electrode that does not use expensive precious metals or enzymes to generate electricity by direct oxidation of an organic substance that serves as a fuel. For example, a biofuel cell in which ascorbic acid or the like is used as a fuel and a carbon cloth impregnated with carbon black is used as an anode without using a noble metal as a catalyst for the anode has been reported (Non-Patent Document 1, Patent Document 1). 4). Furthermore, a study example has also been reported in which carbon black and a carbon felt coated with a polyvinyl pyridine resin are used for the anode, and a solution in which imidazole or the like is used in combination with ascorbic acid is used as the fuel to improve power generation characteristics (Patent Document) 5). However, the output characteristics are still insufficient because no catalyst is used.

JP, 2005-310613, A JP 2006-49215 A WO2012105462 WO2004019436 WO2014098171

Electrochem. Solid-State Lett. (2003), volume 6, issue 12, 257-259.

Since the above fuel cells use organic substances that are safe for living organisms as fuels, they are expected to be used as power sources for wearable devices and implant devices for living organisms. However, at present, expensive noble metal catalysts are used for the cathode and the anode, and there is a problem in material cost. When an enzyme is used for the cathode and the anode, the durability is not sufficient in addition to the material cost. Further, if no precious metal catalyst or enzyme is used, further improvement of output is required.

An object of the present invention is to provide a catalyst ink composition for a biofuel cell anode, a biofuel cell anode, and a biofuel cell device which are excellent in output and durability and which use a reducing organic material as a fuel at a low cost.

The present inventor has reached the present invention as a result of repeated studies to solve the above problems.
That is, the present invention relates to a catalyst ink composition for a biofuel cell anode, which uses as a fuel a reducing organic substance containing at least a conductive carbon material (A) and a nitrogen-containing heterocyclic compound (B).

In the present invention, the catalyst ink composition for a biofuel cell anode is characterized in that the mass ratio of the conductive carbon material (A) and the nitrogen-containing heterocyclic compound (B) is 5:95 to 99:1. Regarding things.

The present invention also relates to the above catalyst ink composition for a biofuel cell anode, wherein the nitrogen-containing heterocyclic compound (B) has a molecular weight of 250 or more and less than 5000.

The present invention also relates to the above catalyst ink composition for a biofuel cell anode, which further comprises a binder resin (C).

The present invention also relates to a biofuel cell anode that uses as a fuel a reducing organic substance having a coating film formed from the above catalyst ink composition for a biofuel cell anode.

The present invention also relates to a biofuel cell device including the biofuel cell anode, the biofuel cell cathode, and a fuel containing a reducing organic substance.

In the present invention, the fuel is at least one organic substance selected from the group consisting of ascorbic acid, ascorbic acid derivative, erythorbic acid, erythorbic acid derivative, nicotinamide adenine dinucleotide, and nicotinamide adenine dinucleotide derivative. The present invention relates to the above biofuel cell device.

By using the biofuel cell of the present invention, it is possible to provide a fuel cell that uses a reducing organic material as a fuel, which is excellent in output and durability. In addition, since it is possible to reduce the use of expensive metal materials and enzymes, it is possible to manufacture low-cost devices.

Hereinafter, the present invention will be described in detail.

<Catalyst ink composition for biofuel cell anode>
The catalyst ink composition for a biofuel cell anode of the present invention can be used for forming an electrode of a biofuel cell anode. The catalyst ink composition for a biofuel cell anode contains at least a conductive carbon material (A) and a nitrogen-containing heterocyclic compound (B).
The mass ratio of the conductive carbon material and the nitrogen-containing heterocyclic compound is not particularly limited as long as conductivity is obtained, but is preferably 5:95 to 99:1, more preferably 15:85 to 95:. It is 5.
The catalyst ink composition for a biofuel cell anode of the present invention may contain a binder resin, a dispersant, and a solvent.
When it contains a binder resin, it is 0.01 to 40% by mass, preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass of the solid content of the whole catalyst ink for biofuel cell anode. It is% by mass.
When it contains a dispersant, it is 0.01 to 10% by mass, preferably 0.05 to 8% by mass, and more preferably 0.1 to 10% by mass of the total solid content of the catalyst ink for a biofuel cell anode. Is about 5% by mass.
When a solvent is contained, it is 1 to 9900% by mass, preferably 5 to 1900% by mass, and more preferably 25 to 9% by mass based on 100% by mass of the solid content of the entire catalyst ink for biofuel cell anode. It is 400 mass %.
The appropriate viscosity of the catalyst ink composition for a biofuel cell anode depends on the method of coating the composition, but in general, it is preferably 10 mPa·s or more and 30,000 mPa·s or less.

<Conductive carbon material (A)>
Next, the conductive carbon material (A) will be described. Although the efficiency of directly oxidizing the fuel is low only with the conductive carbon material, the fuel can be efficiently oxidized directly by combining with the nitrogen-containing heterocyclic compound (B). The conductive carbon material used in the present invention is not particularly limited as long as it is a conductive carbon material that functions as a biofuel cell, as long as it can extract electrons from the anode reaction, The higher the electron conductivity, the more easily the anodic reaction occurs, which leads to an increase in current, which is preferable.

An inorganic carbon material is preferable as the conductive carbon material used in the present invention. For example, graphite, carbon black (furnace black, acetylene black, ketjen black, medium thermal carbon black, nanoporous carbon), activated carbon, carbon nanohorn, carbon fiber (carbon nanotube, carbon nanofiber, carbon felt), graphene, hetero element and And/or a carbon material doped with a base metal element. Carbon materials have various crystallinity, particle diameter, shape, BET specific surface area, pore volume, pore diameter, bulk density, DBP oil absorption, surface acid-basic degree, surface hydrophilicity, conductivity, etc., depending on the type and manufacturer. Since the physical properties and costs are different, it is possible to select the most suitable material according to the intended use and the required performance.

As the graphite, for example, artificial graphite or natural graphite can be used. Artificial graphite is an artificially oriented fine graphite crystal with an irregular array by heat treatment of amorphous carbon, and is generally manufactured from petroleum coke or coal-based pitch coke as the main raw material. It As the natural graphite, flake graphite, lump graphite, earth graphite and the like can be used. It is also possible to use expanded graphite obtained by chemically treating scaly graphite (also referred to as expandable graphite), expanded graphite obtained by heat treatment of expanded graphite and expansion, and then miniaturization or pressing. I can.

The surface of these graphites has been subjected to surface treatment, such as epoxy treatment, urethane treatment, silane coupling treatment, and oxidation treatment, in order to increase the affinity with the binder resin as long as the characteristics of the present invention are not impaired. Good.

The average particle size of the graphite used is preferably 0.5 to 500 μm, and particularly preferably 2 to 100 μm.

In the present invention, the average particle size is a particle size (D50) at which the volume ratio of the particles is 50% when the volume ratio of the particles is integrated in the volume particle size distribution. Particle size distribution meter, for example, a dynamic light scattering particle size distribution meter (“Microtrac UPA” manufactured by Nikkiso Co., Ltd.).

As commercially available graphite, for example, as flaky graphite, CMX, UP-5, UP-10, UP-20, UP-35N, CSSP, CSPE, CSP, CP, CB-150, CB manufactured by Nippon Graphite Industry Co., Ltd. -100, ACP, ACP-1000, ACB-50, ACB-100, ACB-150, SP-10, SP-20, J-SP, SP-270, HOP, GR-60, LEP, F#1, F #2, F#3, CX-3000, FBF, BF, CBR, SSC-3000, SSC-600, SSC-3, SSC, CX-600, CPF-8, CPF-3, CPB- manufactured by Chuetsu Graphite Co., Ltd. 6S, CPB, 96E, 96L, 96L-3, 90L-3, CPC, S-87, K-3, CF-80, CF-48, CF-32, CP-150, CP-100, CP, HF-. 80, HF-48, HF-32, SC-120, SC-80, SC-60, SC-32, EC1500, EC1000, EC500, EC300, EC100, EC50 manufactured by Ito Graphite Industry Co., Ltd. 10099M manufactured by Nishimura Graphite Co., Ltd. , PB-99 and the like. Examples of the spherical natural graphite include CGC-20, CGC-50, CGB-20, and CGB-50 manufactured by Nippon Graphite Industry Co., Ltd. Examples of the earth-like graphite include Blue P, AP, AOP, P#1 manufactured by Nippon Graphite Industry Co., Ltd., and APR, S-3, AP-6, 300F manufactured by Chuetsu Graphite Co., Ltd. As artificial graphite, PAG-60, PAG-80, PAG-120, PAG-5, HAG-10W, HAG-150 manufactured by Nippon Graphite Industry Co., Ltd., RA-3000, RA-15, RA- manufactured by Chuetsu Graphite Co., Ltd. 44, GX-600, G-6S, G-3, G-150, G-100, G-48, G-30, G-50, SEC carbon SGP-100, SGP-50, SGP-25. , SGP-15, SGP-5, SGP-1, SGO-100, SGO-50, SGO-25, SGO-15, SGO-5, SGO-1, SGX-100, SGX-50, SGX-25, SGX. -15, SGX-5 and SGX-1 are mentioned.

As carbon black, furnace black produced by continuously thermally decomposing a gas or liquid raw material in a reaction furnace, especially Ketjen black made from ethylene heavy oil as a raw material, and burning the raw material gas to burn the flame into the channel steel bottom surface. Channel blacks that have been rapidly cooled and deposited to heat, thermal blacks obtained by periodically repeating combustion and thermal decomposition using gas as a raw material, especially various materials such as acetylene black using acetylene gas as a raw material, or 2 More than one type can be used together. Further, commonly used oxidation-treated carbon black, hollow carbon and the like can also be used.

Oxidation treatment of carbon is carried out by subjecting carbon to high temperature treatment in air or secondary treatment with nitric acid, nitrogen dioxide, ozone, etc., such as phenol group, quinone group, carboxyl group, carbonyl group. This is a treatment in which an oxygen-containing polar functional group is directly introduced (covalent bond) to the carbon surface, and is generally performed to improve the dispersibility of carbon. However, since the conductivity of carbon generally decreases as the amount of introduced functional groups increases, it is preferable to use carbon that has not been subjected to oxidation treatment.

The larger the specific surface area of the carbon black used, the more the number of contact points between the carbon black particles increases, which is advantageous for lowering the internal resistance of the electrode. Is a specific surface area (BET) obtained from the adsorption amount of nitrogen, and it is desirable to use a specific surface area (BET) of 10 m ² /g or more and 3000 m ² /g or less, preferably 20 m ² /g or more and 1500 m ² /g or less.

The particle size of the carbon black used is preferably 0.005 to 1 μm in primary particle size, and particularly preferably 0.01 to 0.2 μm. However, the primary particle size mentioned here is an average of the particle sizes measured by an electron microscope or the like.

Examples of commercially available carbon blacks include Toka Black #4300, #4400, #4500, #5500 manufactured by Tokai Carbon Co., Printex L manufactured by Degussa, Raven 7000, 5750, 5250, 5000 ULTRAIII manufactured by Columbyan, and 5000 ULTRA, Conductex SC ULTRA, Conductex 975 ULTRA, PUERBLACK 100, 115, 205, Mitsubishi Chemical Corporation #2350, #2400B, #2600B, #3050B, #3030B, #3230B, #3350B, #3400B, #5400B, Cabot Corporation. MONARCH1400, 1300, 900, VulcanXC-72R, BlackPearls2000, TIMCAL's Ensaco250G, Ensaco260G, Ensaco350G, Furnace black such as SuperP-Li), Lion's EC-300J, EC-600JD's Ketjenblack, etc. DENKA BLACK, DENKA BLACK HS-100, FX-35 and other acetylene blacks, Knobel MH grade, Knobel P(2)010 grade, Knobel P(3)010 grade, Knobel P(4)050 grade, Knobel MJ( 4) Nanoporous carbons manufactured by Toyo Tanso Co., Ltd. such as 030 grade and Knobel MJ(4)010 grade can be mentioned, but the invention is not limited to these and two or more kinds may be used in combination.

Specific examples of the activated carbon include phenol-based, coconut husk-based, rayon-based, acrylic-based, coal-petroleum-based pitch coke, mesocarbon microbeads (MCMB) and the like activated carbon. It is preferable that the specific surface area is large so that an interface having a larger area can be formed with the same mass. Specifically, the specific surface area is preferably 30 m ² /g or more, more preferably 500 to 5000 m ² /g, and further preferably 1000 to 3000 m ² /g.

As the carbon fiber, those obtained by firing from a petroleum-derived raw material are preferable, but those obtained by firing from a plant-derived raw material can also be used. Further, the carbon nanotubes include single-walled carbon nanotubes in which a graphene sheet forms a tube having a diameter in the nanometer range, and multi-walled carbon nanotubes in which graphene sheets are multilayered. Therefore, the diameter of the multi-walled carbon nanotube shows a large value of 30 nm, compared with 0.7 to 2.0 nm of a typical single-walled carbon nanotube.

Commercially available carbon fibers include vapor grown carbon fibers such as VGCF manufactured by Showa Denko KK, single-walled carbon nanotubes such as EC1.0, EC1.5, EC2.0, EC1.5-P manufactured by Meijo Nano Carbon Co., Ltd. , FloTube 9000, FloTube 9100, FloTube 9110, FloTube 9200 manufactured by CNano, NC7000 manufactured by Nanocyl, and 100T manufactured by Knano.

<Nitrogen-containing heterocyclic compound (B)>
Next, the nitrogen-containing heterocyclic compound (B) will be described. The fuel cannot be directly oxidized only by the nitrogen-containing heterocyclic compound, but the fuel can be directly oxidized by combining with the conductive carbon material (A).
The nitrogen-containing heterocyclic compound (B) used in the present invention is an aromatic or aliphatic cyclic compound which contains at least one nitrogen atom and may further contain an oxygen atom, a sulfur atom or a phosphorus atom. Say.
Specific examples of the nitrogen-containing heterocyclic compound (B) include pyrrole, imidazole, pyrazole, pyridine, azatropylidene, thiazole, imidazoline, thiazine, triazole, indole, isoindole, benzimidazole, purine, benzotriazole, quinoline, Examples thereof include low molecular weight nitrogen-containing heterocyclic compounds such as isoquinoline, quinazoline, quinoxaline, carbazole and acridine, and polymers of monomers containing these rings.
Further, a preferable example of the nitrogen-containing heterocyclic compound (B) is a nitrogen-containing organic pigment, and specifically, a phthalocyanine pigment, an azo pigment, a porphyrin pigment, a quinacridone pigment, an anthraquinone pigment, a dioxazine pigment, a diketopyrroloyl pigment. Pyrrole pigment, benzimidazolone pigment, indigo pigment, thioindigo pigment, perylene pigment, perinone pigment, isoindolinone pigment, quinoline pigment, indanone pigment, spiro pigment, azobarbituric acid pigment, thiazine indigo pigment, triazine pigment, carbazole pigment And so on.
These pigments may be derivatives or metal complexes. For example, when phthalocyanine is used as an example, phthalocyanine, naphthalocyanine, phthalocyanine derivatives such as 2,9,16,23-tetra-tert-butylphthalocyanine, and metal of phthalocyanine. It indicates a complex or a metal complex of a phthalocyanine derivative. The transition metal used for the metal complex contains at least one selected from copper, iron, cobalt, nickel, manganese, titanium, vanadium, zinc, tin, aluminum, magnesium and the like.

As these specific nitrogen-containing organic pigments,
Examples of red pigments include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 37, 38, 41, 47, 48, 48:1, 48:2, 48:3, 48:4, 49, 49:1, 49:2, 50:1, 52:1, 52:2, 53, 53:1, 53:2, 53: 3, 57, 57:1, 57:2, 58:4, 60, 63, 63:1, 63:2, 64, 64:1, 68, 69, 81, 81:1, 81:2, 81: 3, 81:4, 112, 114, 122, 123, 144, 146, 147, 149, 151, 166, 169, 170, 173, 175, 176, 177, 178, 179, 181, 183, 184, 185, 187, 188, 190, 193, 194, 200, 202, 206, 207, 208, 209, 210, 214, 220, 221, 237, 238, 239, 242, 243, 245, 247, 249, 250, 251, 253, 254, 255, 256, 257, 258, 260, 262, 263, 264, 266, 267, 268, 269, 270, 271, 272, 273, 274, 276 and the like.

Examples of orange pigments that work similarly to red pigments include C.I. I. Pigment Orange 36, 38, 43, 51, 55, 59, 61, 62, 64, 66, 69, 71 or the like can be used.

Examples of blue pigments include C.I. I. Pigment Blue 1, 9, 14, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 19, 25, 56, 60, 61, 61:1, 62, 63, 66, 68, 75, 76, 78, 79 and the like.

Examples of green pigments include C.I. I. Pigment Green 1, 4, 7, 8, 10, 13, 18, 36, 48, 58.

Examples of the yellow pigment include C.I. I. Pigment Yellow 1, 1:1, 2, 3, 4, 5, 6, 9, 10, 12, 13, 14, 16, 17, 24, 34, 55, 61, 62, 62:1, 63, 64, 65, 73, 74, 75, 81, 83, 87, 93, 94, 95, 97, 100, 101, 104, 105, 108, 109, 110, 111, 116, 117, 120, 126, 127, 127: 1, 128, 129, 133, 134, 136, 138, 139, 142, 147, 148, 150, 151, 153, 154, 155, 165, 166, 167, 168, 169, 170, 172, 173, 174, 175, 176, 180, 181, 182, 183, 185, 188, 190, 191, 191: 1, 192, 193, 194, 195, 198, 199, 202, 203, 204, 205, 206 and the like. it can.

Examples of purple pigments include C.I. I. Pigment Violet 1, 2, 2:2, 3, 3, 19, 23, 25, 27, 29, 32, 37, 39, 42, 44, 50 and the like.

The molecular weight of the nitrogen-containing heterocyclic compound used in the present invention is not particularly limited as long as there is no problem such as dissolution in an electrolytic solution, but the molecular weight is preferably 250 or more and less than 5000. If the molecular weight is small, it may be dissolved in the electrolytic solution and the electrode structure may be destroyed to impair the power generation characteristics. On the other hand, if the molecular weight is large, uniform mixing with the conductive carbon material is difficult, and contact with the conductive carbon material is likely to be uneven, which deteriorates the conductivity of the electrode and impairs power generation characteristics. It may end up.

<Binder resin (C)>
Next, the binder resin (C) will be described. By using the binder resin, the conductive carbon material (A) and the nitrogen-containing heterocyclic compound (B) and those and the base material can be strongly bound to each other, thereby improving good power generation characteristics and durability. You can Examples of the binder resin include polyurethane resin, polyamide resin, acrylonitrile resin, acrylic resin, butadiene resin, polyvinyl butyral resin, polyolefin resin, polyester resin, polystyrene resin, EVA resin, polyvinylidene fluoride resin. One or more selected from the group consisting of resins and silicone resins can be included. However, the binder resin is not limited to these resins, and the binder resin may be used alone or in combination of two or more kinds.
As such a binder resin, a solvent-based resin used by being dissolved in an organic solvent or an aqueous resin used by being dissolved or dispersed in water can be used.
In addition, the binder resin may be a curable resin that undergoes a curing (crosslinking) reaction after producing a catalyst ink composition for a biofuel cell anode in which a conductive carbon material, a nitrogen-containing heterocyclic compound and a binder resin are mixed. it can. As the binder resin, a self-curable binder resin may be selected or combined with a curing agent to be described later, and the catalyst ink composition for a biofuel cell anode may be coated on a substrate and then cured (crosslinked).

The solvent-based resin used by dissolving it in an organic solvent will be described.

<Polyurethane resin>
The method for synthesizing the polyurethane resin is not particularly limited. For example, the polyol compound (a) is reacted with the diisocyanate (b), or the polyol compound (a), the diisocyanate (b), and the diol compound (c) having a carboxyl group. To obtain a urethane prepolymer (d) having an isocyanate group, further reacting the urethane prepolymer (d) with a polyamino compound (e), or in any of the above three cases, reacting as necessary. Examples thereof include those obtained by reacting a terminating agent.

As the polyol compound (a), various polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene glycols, or a mixture thereof, which are generally known as a polyol component constituting a polyurethane resin, can be used.

The number average molecular weight (Mn) of the above-mentioned polyol compound takes into consideration the solubility of the polyurethane resin in the production of the catalyst ink composition for a biofuel cell anode, the durability of the biofuel cell anode to be formed, the binding strength, etc. The range is preferably 580 to 8000, more preferably 1000 to 5000.
The above polyol compounds may be used alone or in combination of two or more kinds. Furthermore, a part of the above-mentioned polyol compounds may be replaced with low-molecular diols, for example, various low-molecular diols used in the production of the above-mentioned polyol compounds, as long as the performance of the polyurethane resin is not lost.

As the diisocyanate compound (b), aromatic diisocyanate, aliphatic diisocyanate, alicyclic diisocyanate, or a mixture thereof can be used, but isophorone diisocyanate is particularly preferable.

Examples of the diol compound (c) having a carboxyl group include dimethylolalkanoic acid such as dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid, and dimethylolpentanoic acid, dihydroxysuccinic acid, and dihydroxybenzoic acid. Particularly, dimethylolpropionic acid and dimethylolbutanoic acid are preferable from the viewpoint of reactivity and solubility.
Conditions for reacting the polyol compound (a) with the diisocyanate (b) and the diol compound (c) having a carboxyl group to obtain the urethane prepolymer (d) having an isocyanate group are as follows: Although there is no particular limitation, the isocyanate group/hydroxyl group equivalent ratio is preferably within the range of 1.05/1 to 3/1. More preferably, it is 1.2/1 to 2/1. The reaction is usually carried out at room temperature to 150° C., and preferably at 60 to 120° C. from the viewpoint of production time and side reaction control.

The polyamino compound (e) functions as a chain extender, and includes ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, norbornanediamine, and 2 It is also possible to use amines having a hydroxyl group such as -(2-aminoethylamino)ethanol, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine and di-2-hydroxypropylethylenediamine. it can. Of these, isophoronediamine is preferably used.

When the polyurethane prepolymer (d) having an isocyanate group is reacted with the polyamino compound (e) to synthesize a polyurethane resin, a reaction terminator can be used in combination to adjust the molecular weight of the obtained polyurethane resin. As the reaction terminator, dialkylamines such as di-n-butylamine, dialkanolamines such as diethanolamine, and alcohols such as ethanol and isopropyl alcohol can be used.

The conditions for reacting the urethane prepolymer (d) having an isocyanate group with the polyamino compound (e) and, if necessary, the reaction terminator are not particularly limited, but free isocyanates at both terminals of the urethane prepolymer are used. When the groups are 1 equivalent, the total equivalent of the amino groups in the polyamino compound (e) and the reaction terminator is preferably in the range of 0.5 to 1.3. More preferably, it is within the range of 0.8 to 0.995.
The weight average molecular weight of the polyurethane resin is preferably in the range of 5,000 to 200,000.

At the time of synthesizing the polyurethane resin, one or two kinds selected from ester solvents, ketone solvents, glycol ether solvents, aliphatic solvents, aromatic solvents, alcohol solvents, carbonate solvents, water, etc. The above can be used in combination.

<Polyamide resin>
The polyamide resin used in the present invention is a general term for polymers having an amide bond obtained by various reactions such as polycondensation of dibasic acid and diamine, polycondensation of aminocarboxylic acid, or ring-opening polymerization of lactam. In addition, various modified polyamides, products produced by partially hydrogenated reaction products, products obtained by partially copolymerizing other monomers, or other substances such as various additives were mixed. It is a broad concept including things.

The polyamide resin used in the present invention is not particularly limited as long as the above conditions are satisfied, but a dimer acid-modified polyamide resin obtained by condensation-polymerizing a dibasic acid containing dimer acid as a main component and polyamines is preferable. .. As the dimer acid for producing the dimer acid-modified polyamide resin, tall oil fatty acid, dimer acid obtained by polymerizing natural monobasic unsaturated fatty acid contained in soybean oil fatty acid and the like is widely used industrially, but in principle In addition, various dicarboxylic acids such as saturated aliphatic, unsaturated aliphatic, alicyclic and aromatic may be used.
In addition to the dimer acid, various dicarboxylic acids can be used as the dibasic acid in order to obtain a polyamide resin having appropriate flexibility.

Further, a dibasic acid having a phenolic hydroxyl group can also be used. By using the dibasic acid having a phenolic hydroxyl group, the phenolic hydroxyl group can be introduced into the side chain of the polyamide resin and can be used for the reaction with the curing agent.

Further, in order to obtain a polyamide resin having an appropriate fluidity when heated, various monocarboxylic acids are used if necessary.
The polyamines as a reaction product when producing the dimer acid-modified polyamide resin are, for example, various diamines such as aliphatic, alicyclic and aromatic diamines, triamines and polyamines.

<Water-based resin>
Next, the water-based resin will be described. Examples of the water-based resin include a water-soluble resin that is used by dissolving it in water, and an aqueous resin particle (generally called an aqueous emulsion) that is used by dispersing resin particles that are insoluble in water in water. These resins may be used alone or in combination of two or more.

The water-soluble resin is not particularly limited as long as it is a water-soluble resin as described above, for example, acrylic resin, polyurethane resin, polyester resin, phenol resin, epoxy resin, polyvinyl alcohol derivative, xanthan gum derivative, Examples include guar gum derivatives, chitosan derivatives, cellulose derivatives, alginic acid, alginic acid derivatives, and corn starch derivatives. Further, a modified product, a mixture, or a copolymer of these resins may be used as long as it is water-soluble. These water-soluble resins may be used alone or in combination of two or more.
The molecular weight of the water-soluble resin is not particularly limited, but the weight average molecular weight is preferably 5,000 to 2,500,000. The weight average molecular weight (Mw) indicates a polyethylene oxide-equivalent molecular weight in gel permeation chromatography (GPC).

As the water-based resin fine particles, (meth)acrylic emulsion, nitrile emulsion, urethane emulsion, diene emulsion (styrene-butadiene rubber (SBR), etc.), fluorine emulsion (polyvinylidene fluoride (PVDF), polytetrafluoroethylene, etc.) (PTFE) and the like. Unlike the water-soluble polymer, the emulsion preferably has excellent binding properties between particles and flexibility (flexibility of the film).

(Particle structure of aqueous resin particles)
Further, the particle structure of the aqueous resin fine particles used in the present invention may be a multilayer structure, so-called core-shell particle. For example, by localizing a resin in which a monomer having a functional group is mainly polymerized in the core part or the shell part, or by providing a difference in Tg and composition depending on the core and the shell, curability and drying can be obtained. Property, film-forming property, and mechanical strength of the binder can be improved.

(Particle size of water-based resin particles)
The average particle diameter of the aqueous resin fine particles used in the present invention is preferably 10 to 500 nm, and more preferably 10 to 300 nm, from the viewpoint of binding properties and particle stability. Further, if a large amount of coarse particles exceeding 1 μm is contained, the stability of the particles is impaired. Therefore, the amount of coarse particles exceeding 1 μm is preferably at most 5% or less. The average particle size in the present invention means a volume average particle size and can be measured by a dynamic light scattering method.

The average particle size can be measured by the dynamic light scattering method as follows. The crosslinked resin fine particle dispersion is diluted with water 200 to 1000 times depending on the solid content. About 5 ml of the diluted solution is injected into the cell of a measuring device [Microtrac (manufactured by Nikkiso Co., Ltd.)], and the solvent (water in the present invention) and the refractive index condition of the resin according to the sample are input, and then the measurement is performed. The peak of the volume particle size distribution data (histogram) obtained at this time is the average particle size of the present invention.

<(Meth)acrylic emulsion>
Next, the (meth)acrylic emulsion will be described. The (meth)acrylic emulsion is an emulsion polymer containing 10 parts by mass or more of a monomer having a (meth)acryloyl group, preferably 20 parts by mass or more, and more preferably 30 parts by mass or more. Good. Since the monomer having an acryloyl group is excellent in reactivity, resin fine particles can be prepared relatively easily. In addition, the biofuel cell anode using the (meth)acrylic emulsion has excellent binding properties.

<Method for producing crosslinked resin fine particles in (meth)acrylic emulsion preferably used in the present invention>
The crosslinked resin fine particles in the (meth)acrylic emulsion preferably used in the present invention are synthesized by a conventionally known emulsion polymerization method.

<Emulsifier used in emulsion polymerization>
As the emulsifier used in the emulsion polymerization in the present invention, any conventionally known emulsifier such as a reactive emulsifier having an ethylenically unsaturated group or a non-reactive emulsifier having no ethylenically unsaturated group may be used. it can.

<Other materials used for reaction>
Further, if necessary, sodium acetate, sodium citrate, sodium bicarbonate or the like as a buffering agent, and octyl mercaptan, 2-ethylhexyl thioglycolate, octyl thioglycolate, stearyl mercaptan, lauryl mercaptan as a chain transfer agent. Suitable amounts of mercaptans such as t-dodecyl mercaptan can be used.

When a monomer having an acidic functional group such as a carboxyl group-containing ethylenically unsaturated monomer is used for the polymerization in the (meth)acrylic emulsion preferably used in the present invention, it is basic before or after the polymerization. It can be neutralized with a compound. When neutralizing, it can be neutralized with ammonia or alkylamines such as trimethylamine, triethylamine, butylamine; alcohol amines such as 2-dimethylaminoethanol, diethanolamine, triethanolamine, aminomethylpropanol; bases such as morpholine. .. However, a base having a high volatility has a high effect on the drying property, and preferable bases are aminomethyl propanol and ammonia.

<Solvent>
Next, the solvent will be described. When the materials in the catalyst ink composition for a biofuel cell anode are uniformly mixed, a solvent can be appropriately used. Examples of such a solvent include organic solvents and water.
The organic solvent, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol methyl ether, diethylene glycol methyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether Depending on the composition of the catalyst ink composition from among ethers such as hexane, heptane, octane and other hydrocarbons, benzene, toluene, xylene, cumene and other aromatics, ethyl acetate, butyl acetate and other esters, etc. Any suitable one can be used. Moreover, you may use 2 or more types of solvents.
When water is used, for example, a liquid medium compatible with water may be used in order to improve dispersibility of the catalyst ink composition and coatability on a substrate.
The liquid medium compatible with water includes alcohols, glycols, cellosolves, amino alcohols, amines, ketones, carboxylic acid amides, phosphoric acid amides, sulfoxides, carboxylic acid esters, and phosphoric acid esters. Examples thereof include ethers, ethers, nitriles, etc., and may be used in a range compatible with water.

Further, a thickening agent, a dispersant, a film-forming aid, a defoaming agent, a leveling agent, a preservative, a pH adjusting agent and the like can be added to the catalyst ink composition for a biofuel cell anode, if necessary.

<Method for preparing catalyst ink composition for biofuel cell anode>
The method for preparing the catalyst ink composition for the biofuel cell anode is not particularly limited. The preparation method is
(1) Each component may be dispersed at the same time,
(2) After dispersing the conductive carbon material in the solvent, other materials may be added,
(3) After the conductive carbon material and the nitrogen-containing heterocyclic compound are dispersed in a solvent, another material may be added,
(4) After the conductive carbon material and the binder resin are dispersed in the solvent, another material may be added,
It can be selected depending on the conductive carbon material, nitrogen-containing heterocyclic compound, binder resin, and solvent used.

<Disperser/Mixer>
As a device used for obtaining the catalyst ink composition for the biofuel cell anode, a disperser or a mixer which is usually used for pigment dispersion can be used.

For example, mixers such as disperser, homomixer, or planetary mixer; homogenizers such as "Clearmix" manufactured by M Technique Co., Ltd. or "Fillmix" manufactured by PRIMIX; paint conditioner (manufactured by Red Devil Co.), ball mill, sand mill Media type dispersing machine such as (Dimino Mill manufactured by Shinmaru Enterprises Co., Ltd.), attritor, pearl mill (“DCP mill” manufactured by Eirich, etc.), or co-ball mill; wet jet mill (“Genus PY” manufactured by Genus, Sugino) Machineless "Starburst", Nanomizer "Nanomizer" etc.), M Technique "Clear SS-5" or Nara Machinery "MICROS" medialess disperser; or other roll mill etc. However, the present invention is not limited to these.

For example, when using a media type disperser, a method in which the agitator and vessel are made of a ceramic or resin disperser, or a metal agitator and a disperser in which the vessel surface is treated with tungsten carbide spraying or resin coating, etc. Is preferably used. Then, as the medium, it is preferable to use glass beads, or ceramic beads such as zirconia beads or alumina beads. Also, when using a roll mill, it is preferable to use a ceramic roll. Only one type of dispersion device may be used, or a plurality of types of devices may be used in combination. Further, when the catalyst-supporting carbon material is easily cracked or crushed by a strong impact, a medialess disperser such as a roll mill or a homogenizer is preferable to the media type disperser.

<Biofuel cell anode>
The biofuel cell anode can be produced by applying a catalyst ink composition for a biofuel cell anode to a substrate to form a coating film.

<Substrate>
The base material used in the anode of the present invention is preferably one having excellent corrosion resistance, electrical conductivity, large surface area, and excellent diffusion of reactants and products, and the material and shape are not particularly limited. For example, in addition to carbon materials such as graphite paper (carbon paper), graphite cloth (carbon cloth) and graphite felt (carbon felt), metallic materials such as stainless steel mesh, copper mesh and platinum mesh can be used. Absent. The conductive base material used for the electrodes may be previously subjected to a water repellent treatment. For example, water repellency is exhibited by impregnating the cathode with a dispersion liquid of PTFE, and drying and heating at about 400° C. A conductive material may be dispersed in the PTFE dispersion liquid. The water repellent treatment is not limited to these.

<Coating method>
The method of applying the catalyst ink composition for a biofuel cell anode of the present invention to a substrate is not particularly limited, and a known method can be used. Examples include gravure coating method, spray coating method, screen printing method, dip coating method, die coating method, roll coating method, doctor coating method, knife coating method, screen printing method or electrostatic coating method. As a drying method, standing drying, blower dryer, warm air dryer, infrared heater, far infrared heater and the like can be used, but the drying method is not particularly limited thereto.

<Biofuel cell device>
A biofuel cell device of the present invention comprises the biofuel cell anode, a biofuel cell cathode, and a fuel containing a reducing organic substance. A separator and an ionic conductor may be included if necessary.

<Biofuel cell cathode>
The biofuel cell cathode can be produced by a conventionally known method or the same material configuration and process as the anode except that an oxygen reduction catalyst is used.
As the enzyme reduction catalyst, a known enzyme used for a biofuel cell cathode can be used.

<Fuel>
The fuel used in the biofuel cell of the present invention contains at least one reducing organic substance that can be directly oxidized on the electrode. Ascorbic acid, an ascorbic acid derivative, erythorbic acid, an erythorbic acid derivative, a nicotinamide adenine dinucleotide, a nicotinamide adenine dinucleotide derivative, a nicotinamide adenine dinucleolinic acid, a citric acid, a tartaric acid etc. can be illustrated. Here, the term "derivative" includes condensates with alcohols and amines such as acid esters and acid amides, as well as those substituted with substituents such as alkyl groups.
Of these, ascorbic acid, erythorbic acid, nicotinamide adenine dinucleotide, nicotinamide adenine dinucleolinic acid, and derivatives thereof are preferable, and ascorbic acid is more preferable.

<Separator>
The separator is not particularly limited as long as it can electrically separate the cathode and the anode (prevents a short circuit), and a conventionally known material can be used. Specifically, polyethylene fiber, polypropylene fiber, glass fiber, resin non-woven fabric, glass non-woven fabric, felt, filter paper, Japanese paper and the like can be used. Further, if the cathode and the anode have a sufficient distance to prevent a short circuit due to contact, a separator may not be used.

<Ion conductor>
The ionic conductor in the present invention conducts ions between the anode and the cathode. The form of the ion conductor is not particularly limited as long as it has ion conductivity. As the ionic conductor, for example, an electrolyte solution in which an electrolyte is dissolved in a liquid such as a phosphate buffer solution, a solid polymer electrolyte, or the like may be used. The solid polymer electrolyte may also have a separator function.

<Applications of biofuel cell devices>
As described above, the biofuel cell using a reducing organic substance as a fuel in the present invention functions as a power source using generated electric power, a self-generating sensor that also serves as a power source and a sensor, an organic substance sensor, a moisture sensor, etc. It is expected to be used for various purposes. As a usage, a different type of battery (coin cell, etc.) is used as a power source, a biofuel cell device using the reducing organic substance of the present invention as a fuel is used as a sensor, or the reducing organic substance of the present invention is used as a fuel in a power source and a sensor. One or more types of fuel cell devices can be used, a biofuel cell device using the reducing organic material of the present invention as a fuel can be used as a power source, and another type of sensor can be used as a sensor.

The power source of the biofuel cell device using the reducing organic material as a fuel in the present invention includes, for example, household power sources, mobile device power sources, disposable power sources, bio-wearable power sources/implant power sources, biomass fuel power sources, IoT sensors. For example, there is a power supply for use, and an energy harvesting power supply that can generate power using the surrounding reducing organic substances as fuel.

Examples of the use of the sensor include, for example, an organic substance sensor for reducing organic substances, a biological sensor for reducing organic substances or body fluids in biological samples such as blood, sweat, urine, stool, tears, saliva, and breath, and water. Sensor for water, food sensor for reducing organic matter in fruits and food, IoT sensor, environmental sensor for reducing organic matter in environment such as air, river and soil, animals, insects, plants And the like. The above may be a self-powered sensor that doubles as a power source and a sensor, or may be used only as a sensor that is not used as a power source. Examples of the biological sensor include a perspiration sensor that senses sweat and water in urine, a urination sensor, and the like. In addition, examples of applications as a wearable sensor for a living body include a urine sensor in which a sensor is provided in a diaper and a percutaneous stick-type perspiration sensor.
As the IoT sensor, a combination of a wireless device and a sensor can be used to wirelessly transmit sensing information to the outside. In that case, the fuel cell device of the present invention using the reducing organic material as a fuel can be preferably used.
For example, a biofuel cell device that uses a reducing organic substance as a fuel is used as a power source and a sensor of a wireless device, or a biofuel cell device that uses a reducing organic substance as a fuel for a power source of a wireless device, and another reducing organic substance is used as a sensor. One or more types of power source for the radio and sensor, such as using a biofuel cell device as a fuel, using a biofuel cell device that uses a reducing organic substance as a power source for the radio, and using a sensor of another method as a sensor Biofuel cell device that uses reducible organic substances as a fuel, another type of sensor is used as a sensor, another type of battery (coin cell, etc.) is used as the power source of the radio, and biofuel that uses reducible organic substances as a sensor A battery device can be used.
When the above IoT sensor is used as a biosensor for a diaper, a biofuel cell device using a reducing organic substance as a fuel can be placed in the diaper and used as follows. In the case of a urination sensor, the fuel in advance is used to sense the water content in the urine, and at the same time the power is generated by using the water to operate the wireless device, or the built-in fuel is used in advance to generate the power using the water content in the urine. The wireless device and another method of urination sensor are operated with the obtained power, or the wireless device is operated with the power of another method battery (coin battery, etc.) by preliminarily incorporating a fuel to detect moisture in urine. it can.

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, unless otherwise indicated, part and% represent a mass part and the mass %, and Mw means a weight average molecular weight.

<Synthesis example (1) Binder resin solution>
A polyester polyol (manufactured by Kuraray Co., Ltd.) obtained from terephthalic acid, adipic acid, and 3-methyl-1,5-pentanediol in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube. "Kuraray Polyol P-2011", Mn=2011) 455.5 parts, dimethylolbutanoic acid 16.5 parts, isophorone diisocyanate 105.2 parts, and toluene 140 parts were charged and reacted at 90°C for 3 hours under a nitrogen atmosphere. To the mixture, 360 parts of toluene was added to obtain a urethane prepolymer solution having an isocyanate group. Next, a mixture of 19.9 parts of isophoronediamine, 0.63 part of di-n-butylamine, 294.5 parts of 2-propanol, and 335.5 parts of toluene was added to the resulting urethane prepolymer solution having an isocyanate group. 969.5 parts was added, the mixture was reacted at 50° C. for 3 hours and then at 70° C. for 2 hours, diluted with 126 parts of toluene and 54 parts of 2-propanol, Mw=61,000, acid value=10 mgKOH/g, urethane prepolymer. A polyurethane resin solution was obtained in which the total equivalent weight of the polyamino compound and the amino groups in the reaction terminator was 0.98 with respect to the free isocyanate groups at both ends of the polymer. This solution was diluted with toluene/methyl ethyl ketone/2-propanol (1/1/1) to obtain a solution of binder resin (C-1) having a solid content of 20%.

<Preparation of Catalytic Ink Composition for Biofuel Cell Anode Using Reducing Organic Material as Fuel>
[Example A1]
Graphene nanoplatelet xGnP-C-750 (manufactured by XGscience) 40 parts, iron phthalocyanine P-26 (manufactured by Sanyo Dye Co.) 20 parts, emulsion type acrylic resin dispersion solution (manufactured by Toyochem: W-168) 40 as a binder resin 40 Parts (50% solid content), 380 parts of water as a solvent, and 20 parts of an aqueous solution of carboxymethyl cellulose as a thickener are mixed in a mixer and further mixed in a sand mill to disperse and use a reducing organic substance as a fuel. A catalyst ink composition (1) for anode was obtained.

[Examples A2 to A9]
Using the materials shown in Table 1 and in the same manner as in Example 1, catalyst ink compositions (2) to (9) for biofuel cell anodes using a reducing organic material as a fuel were obtained.

[Comparative Example A1]
70 parts of graphene nanoplatelets xGnP-C-750 (manufactured by XGscience), 30 parts of polyfukka vinylidene #1700 (manufactured by Kureha) as a binder resin, and 400 parts of N-methylpyrrolidone as a solvent were mixed in a mixer, and further mixed. It was placed in a sand mill and dispersed to obtain a catalyst ink composition (I) for a biofuel cell anode using a reducing organic material as a fuel.

[Comparative Example A2]
60 parts of iron phthalocyanine P-26 (manufactured by Sanyo dye company), 40 parts of emulsion type acrylic resin dispersion solution (manufactured by Toyochem Co.: W-168) as binder resin (solid content 50%), 380 parts of water as solvent, and further thickening 20 parts of carboxymethyl cellulose as an agent was put into a mixer and mixed, and then put into a sand mill and dispersed to obtain a catalyst ink composition (II) for a biofuel cell anode, which uses a reducing organic substance as a fuel.

[Comparative Example A3]
Acetylene black HS-100 (manufactured by Denka) 60 parts, poly(4-vinylpyridine) (Mw=160,000, manufactured by Sigma-Aldrich) as a binder resin, N-methylpyrrolidone 400 parts as a solvent, and a thickener As a result, 20 parts of carboxymethyl cellulose was put into a mixer and mixed, and then put into a sand mill and dispersed to obtain a catalyst ink composition (III) for a biofuel cell anode using a reducing organic material as a fuel.

<Fabrication of biofuel cell anode using reducing organic material as fuel>
[Examples B1 to B9, Comparative Examples B1 to B3]
The catalyst ink compositions (1) to (9) and (I) to (III) for biofuel cell anodes using the reducing organic substances as fuels of Examples A1 to A9 and Comparative Examples A1 to A3 were dried with a doctor blade. The biocatalyst anode catalyst layer using a reducing organic material as a fuel is coated on a conductive base material (carbon paper, manufactured by Toray Industries, Inc.) so that the basis weight is 1.5 mg/cm ^2, and then the oven is heated at 100° C. In it, it was dried for 1 hour to prepare biofuel anodes (1) to (9) and (I) to (III) using a reducing organic material as a fuel.

<Evaluation of power generation characteristics of biofuel cell anode using reducing organic material as fuel>
The working electrode shown in Table 1 has an anode for a biofuel cell that uses the reducing organic material as a fuel, the counter electrode is a platinum wire coil, the reference electrode is an Ag/AgCl electrode, and the reducing organic fuel ascorbic acid is 10 mM. An electrochemical cell was prepared using the 100 mM phosphate buffer solution (pH 7.0) thus added as an electrolyte solution. Next, using a potentio-galvanostat, at room temperature, a Linear Sweep Voltammetry (LSV) measurement was performed in a range of a measurement potential of −0.1 to +0.1 V, and a current (μA/cm ² ) at a measurement potential of +0.1 V. ) Was calculated. The evaluation results are shown in Table 2.

A-1: Graphene nanoplatelet xGnP-C-750 (manufactured by XGscience)
A-2: Acetylene black HS-100 (manufactured by Denka)
A-3: Ketjen Black EC-300J (manufactured by Lion Corporation)
B-1: Iron phthalocyanine (manufactured by Sanyo Dye Co., molecular weight 568.38)
B-2: Copper (II) 5,9,14,18,23,27,32,36-octabutoxy-2,3-naphthalocyanine (Sigma-Aldrich, molecular weight 1353.15)
B-3: Carbazole (manufactured by Tokyo Kasei Co., molecular weight 167.21)
B-4: Pigment Red 255 (manufactured by Tokyo Kasei Co., molecular weight 288.31)
B-5: Phthalocyanine (manufactured by Tokyo Kasei Co., molecular weight 514.55)
B-6: 5-aminobenzimidazole (Tokyo Kasei Co., molecular weight 133.15)
B-7: Polyvinylimidazole (Maruzen Petrochemical Co., Ltd., molecular weight 10,000)
B-8: Imidazole (Tokyo Kasei Co., 68.08)
C-1: Polyurethane resin solution (Synthesis example (1), solid content 20%)
C-2: Acrylic resin dispersion solution W-168 (manufactured by Toyochem, solid content 50%)
C-3: Polyvinylidene fluoride #1700 (manufactured by Kureha)
C-4: poly(4-vinylpyridine) (Sigma-Aldrich)

D-1: Carboxymethyl cellulose D-2: Polyvinylpyrrolidone

NMP: N-methylpyrrolidone TMP: Toluene/methyl ethyl ketone/2-propanol (1/1/1)

<Fabrication of biofuel cell cathode using reducing organic matter as fuel>
A catalyst ink for a biofuel cell cathode was prepared in the same manner as in Example A-1, except that the graphene nanoplatelet xGnP-C-750 and the iron phthalocyanine P-26 of Example 1 were changed to the carbon catalyst for the cathode. A cathode for a biofuel cell was produced in the same manner as in Example B-1.
The carbon catalyst for the cathode was Ketjen Black EC-600JD (manufactured by Lion Specialty Chemicals) and cobalt phthalocyanine (manufactured by Tokyo Kasei) with a mass ratio of 1/0.5 (Ketjen black/cobalt phthalocyanine). Each is weighed and dry-mixed to obtain a mixture, which is then filled in an alumina crucible and heat-treated at 700° C. for 2 hours in an electric furnace in a nitrogen atmosphere to be used for synthesis. did.

<Preparation of biofuel cell using reducing organic material as fuel>
[Examples C1 to C9, Comparative Examples C1 to C3]
The biofuel cell cathode and the biofuel cell anode prepared above, and a separator in which 100 mM phosphate buffer solution (pH 7.0) added so that ascorbic acid was 10 mM was soaked in a filter paper as a cathode. A biofuel cell using a reducing organic material as a fuel was produced by sandwiching it between the anodes, and the output characteristics were evaluated by LSV measurement at room temperature. The output characteristics were compared by the percentage (%) of the maximum output in each example with respect to the maximum output of Comparative Example 1 calculated from the LSV measurement, and evaluated according to the following criteria.
A: Percentage of maximum output relative to Comparative Example 1 is 300% or more.
◯: Percentage of maximum output relative to Comparative Example 1 is 200% or more and less than 300%.
B: Percentage of maximum output relative to Comparative Example 1 is 150% or more and less than 200%.
Δ: Percentage of maximum output relative to Comparative Example 1 is 100% or more and less than 150%.
X: Percentage of maximum output relative to Comparative Example 1 is less than 100%.

From the results of Examples B1 to B9, it was revealed that the power generation characteristics were better than those of Comparative Examples. Therefore, a catalyst ink for a biofuel cell anode combining the conductive carbon material of the present invention and a nitrogen-containing heterocyclic compound It is considered that, due to the above, good catalyst characteristics were realized for reducing organic substances. In particular, the output characteristics of Examples B1, B2, B4 and B5 were good. The balance of the composition ratio of the conductive carbon material and the nitrogen-containing heterocyclic compound, and the reason that the nitrogen-containing heterocyclic compound had a moderately large molecular weight, the conductive path (network) of the catalyst layer was very good, and the nitrogen-containing heterocyclic compound was contained. It is considered that the power generation characteristics were good because the heterocyclic compound was difficult to dissolve in the electrolytic solution and the structure of the anode did not collapse.
On the other hand, from the results of Examples C1 to C9, it was clarified that the fuel cell operates as a biofuel cell exhibiting better output characteristics than the comparative example. It has been clarified that the catalyst ink for a biofuel cell anode in which the conductive carbon material and the nitrogen-containing heterocyclic compound of the present invention are combined has realized good catalyst characteristics for reducing organic substances.

Claims (7)

A catalyst ink composition for a biofuel cell anode, which uses, as a fuel, a reducing organic material containing at least a conductive carbon material (A) and a nitrogen-containing heterocyclic compound (B). The catalyst ink composition for a biofuel cell anode according to claim 1, wherein a mass ratio of the conductive carbon material (A) and the nitrogen-containing heterocyclic compound (B) is 5:95 to 99:1. The catalyst ink composition for a biofuel cell anode according to claim 1 or 2, wherein the nitrogen-containing heterocyclic compound (B) has a molecular weight of 250 or more and less than 5,000. The catalyst ink composition for a biofuel cell anode according to claim 1, further comprising a binder resin (C). A biofuel cell anode using a reducing organic material as a fuel, which has a coating film formed from the catalyst ink composition for a biofuel cell anode according to claim 1. A biofuel cell device comprising the biofuel cell anode according to claim 5, a biofuel cell cathode, and a fuel containing a reducing organic substance. The fuel is characterized by containing at least one organic substance selected from the group consisting of ascorbic acid, ascorbic acid derivative, erythorbic acid, erythorbic acid derivative, nicotinamide adenine dinucleotide, and nicotinamide adenine dinucleotide derivative. The biofuel cell device according to claim 6.