JP4874092B2 - Conductive polymer, conductive polymer composition, and use thereof - Google Patents

Description

Field of Invention

  The present invention relates to conductive polymers and conductive polymer electrode compositions and their use, in particular carbon electrodes joined with polymers.

  Conductive polymers and conductive polymer compositions have industrial uses such as electrodes, separators, bipolar plates, electromagnetic shields and antistatic products in electrochemical cells.

  Carbon electrode materials include fuel cells, batteries, energy storage capacitors, catalyst supports, metal and concrete corrosion prevention, water purification, water sterilization, desalination, sludge treatment, acid mine wastewater treatment, flue gas desulfurization, It is used or has potential for many electrochemical applications and industrial processes, including soil amendments, metal recovery, electrochemical sensors and electrosynthesis.

  Electrochemical water treatment methods are becoming increasingly important because they are more beneficial than conventional physical, chemical and biological methods. Being electrically driven, rapid reaction rates can be achieved, and smaller and more efficient equipment can be designed. Electrochemical methods have the advantage of replacing the need for chemical processing and biological systems and other benefits such as reduced sludge formation and reduced need to transport hazardous chemicals.

  According to a report from Water UK in 2002 (ENDS report 339 1/4/03), water treatment in the UK has become more expensive to improve quality standards. The energy used for both drinking water and wastewater treatment is increasing. Drinking water currently requires 600 kilowatt hours per megaliter for processing and supply for the additional processing and pumping required to meet Cryptosporidium regulations, rising 28% since 1998. Even on the wastewater side, energy use has increased by 37% from 437 kWh / Ml in 1998 to 598 kWh / Ml. This is because environmental quality requirements are becoming increasingly stringent and the company is obliged to introduce more secondary treatment and UV sterilization facilities, increasing the amount of sewage sludge to be treated and disposed of.

  Clearly there is a need for more efficient and low cost water treatment. Although not widely used, electrochemical water treatment devices have been developed and are commercially available. Existing carbon materials used for electrodes are typically graphite, porous carbon, such as carbon felt, airgel, nanofoam and reticulated vitreous carbon. Graphite is relatively cheaper than porous carbon material, but is a brittle material and requires high temperature machining techniques to achieve the design shape.

  Porous carbon electrodes are manufactured from a thermosetting resin by a process in which the resin is pre-formed into a specific shape and then exposed to high temperatures for a long time until complete carbonization occurs. The volume of carbon formed is much smaller than the original resin size, which reduces the product yield. This is a serious problem when a specific geometric shape or size is required. This manufacturing technique also has the disadvantages of high material costs and low material strength because the precursor carbon “shrinks” at high carbonization temperatures.

  High surface area steric carbon electrodes are produced by carbonizing organic compounds using sol-gel technology. A vitreous carbon material having a high surface area and high conductivity can be produced by the pyrolysis method. However, this manufacturing technique is very expensive to manufacture and may require additional processing to produce a particular geometry.

  Porous carbon electrodes made from a polymeric binder mixed with carbon powder are generally poor conductors. The disadvantage of using a polymeric binder to form a carbon electrode is that the conductivity of the electrode is degraded because most binders are non-conductive.

  Clearly, the production of carbon electrodes is limited to low volume production techniques and the resulting products are expensive due to machining needs, processing costs, or both.

  Manufacturing techniques used in the manufacture of carbon electrodes can be improved, and there is a need for a more efficient, inexpensive, more flexible and method for manufacturing large quantities of carbon electrodes.

Summary of the Invention

  There is a need for solutions to these problems.

According to the present invention,
(A) negative electrode,
An electrical device comprising (b) a positive electrode, and (c) an electrolyte means, and optionally (d) a separator and / or a bipolar plate, wherein the one or more electrodes and / or separator or bipolar plate are Provided is an electrical device comprising an ester-cured alkaline phenolic resole resin comprising a conductive alkali salt and doped with a conductive material.

  The bipolar and / or separator plate used in the electrical device of the invention is preferably a separator plate of the invention. Of course, if the electrical device comprises a bipolar plate, the device need not comprise a negative electrode (a) and a positive electrode (b). This is because bipolar plates contain negative and positive electrodes.

  In accordance with the present invention, a separator plate suitable for use in a fuel cell having one or more gas counter-current flow fields, the plate comprising a conductive alkaline salt and doped with a conductive material, an ester cured. A separator plate comprising the alkaline phenolic resole resin.

  According to the present invention, there is further provided an electrode comprising an ester-cured alkaline phenolic resin comprising a conductive alkali salt and doped with a conductive material.

  Cured phenolic resins are thermosetting polymers and are superior to other resin systems due to their good thermal and mechanical stability and their flame resistance. Usually, these resins are also excellent in electrical insulation ability. Thus, it is surprising that ester cured alkaline resole resins are useful as electrodes.

  It is known that phenolic resins can be cured by reaction with organic esters under alkaline conditions. The ester curing of such alkaline phenolic resole resins is described in DE-C No. 1,065,605, DE-C No. 1,171,606, JP-A no. 49-16793 and JP-A no. 50-130627. According to these documents, a highly alkaline phenolic resole resin in an aqueous solution can be cured by contacting the resin with an ester in liquid or gaseous form at room temperature by reaction with an organic ester. Such techniques are used for sand bonding in fireproof applications such as mold and core manufacturing (US Pat. Nos. 4,426,467, 4,68,359 and 4,474,904). ). A process of this kind is also described in EP 0241156, in which an aqueous alkaline phenol-formaldehyde resin is cured with an ester curing agent to agglomerate the wet coal powder, followed by drying and agglomeration. It is cured.

  Ester-cured alkaline phenolic resole resins have been used in the industry for over 20 years. Industrial applications benefit from this rapid room temperature polymerization reaction. This polymer is unique in that it contains a high level of electrolytic salt that is formed in situ as a by-product of the polymerization reaction. We have found that due to the presence of salt in the polymer, this polymer has much higher conductive properties than other thermoset polymers.

  We have also found that the conductivity of the ester-cured alkaline phenolic resole resin is enhanced by adding a conductive material to the polymer composition. Any conductive material can be added to the resin or ester component to improve conductivity as long as the material is compatible with the polymer component and does not interfere with the cure mechanism. Carbon, particularly in the form of graphite, is very compatible with the resin and ester components of this polymer system and does not affect the chemistry of the reaction.

  The carbon form preferentially selected to improve conductivity is preferably natural or synthetic graphite powder or flakes. The main requirements for carbon are resin compatibility, carbon wettability and electrical conductivity. Two or more types of carbon can be used in combination with different carbons, such as activated carbon powder, polyacrylonitrile (PAN) based carbon fibers, pitch based carbon fibers and a mixture of carbon black. Combinations of carbon and non-carbon conductive fillers such as metal and metal oxide powders, and metal-coated graphite and glass such as nickel-coated graphite and silver-coated glass can be used. Alternatively, one or more non-carbon conductive fillers themselves can be used.

  Non-carbon conductive fillers that are compatible with the ester component of the resin and the conductive mixture and do not inhibit the polymerization reaction, such as metal and metal oxide powders and metal-coated graphite and glass, such as nickel-coated graphite and Silver-coated glass can be used as a conductive filler.

  The resin is preferably a conductive material and the weight ratio of resin to conductive material is preferably at least 0.001: 1, more preferably at least 0.002: 1, most preferably at least 1: 1, preferably Doping is done in such an amount that it is at most 100: 1, more preferably at most 20: 1, most preferably at most 10: 1.

Ester-cured alkaline phenolic resoles are distinguishable from acid-cured resoles in that the polymer matrix of the cured alkaline phenolic composition contains high levels of alkaline salts. Dispersing or dissolving a carboxylic acid salt is very difficult in a liquid resol because the phenolic resin loses solubility and may precipitate out of solution. Second, to acidify the phenolic resole containing a salt of dispersed carboxylic acid, CO ₂ is generated by the salt reacts with the acid. Thus, a unique feature of cured alkaline resole compositions is the presence of large amounts of carboxylate in the cured polymer matrix formed during the curing reaction.

In the present invention, as an advantage of using an ester-cured alkaline phenolic resole resin containing a conductive alkali salt and doped with a conductive material,
・ Because the composition can be molded at room temperature, the manufacturing process becomes faster, easier and cheaper.
The composition can be molded under low and high pressure,
-Since the resin has a higher conductivity than the binder normally used for carbon bonding, the decrease in conductivity is minimized,
-Since the resin is cured at room temperature and shrinkage is minimized, there is no need for machining, and a highly durable product with good material strength is obtained.
The resin can be diluted indefinitely with water, and the added water can improve the wettability of the carbon or graphite powder or flakes to produce an electrode material with a high carbon content,
-Resin can be foamed to produce a three-dimensional, high surface area porous conductive structure,
The resin can be doped with a conductive filler,
・ Starting materials are relatively inexpensive, and manufacturing costs can be saved.
・ Mass production is possible,
-The reaction is only mildly exothermic and can be used to form large, bulky products.

  To illustrate cost savings, the following numbers are provided. Commercially available carbon RF [resorcinol-formaldehyde] airgel materials are supplied by Marketetech International Inc. in the form of blocks, granules, powders and paper. As of November 2003, the price of a 100g RF aerogel is US $ 185 before machining. The price of the RF airgel paper sheet (3.5 inches x 10 x 0.01) is US $ 665 per 100 sheets. Carbon airgel is more expensive, 100 g US $ 275, and 100 paper sheets are $ 100. A molded form 100 g of the carbon-doped resin material used in the present invention would be about US $ 0.42.

  For low cost electrode materials such as graphite and copper, this material cost represents only a small portion of the total electrode manufacturing cost. Graphite and copper require high temperature machining tools to produce precise shapes. Manufacturing time, machining time, labor and scrap are very important to the overall cost. The carbon-doped resin used in the present invention can be molded into a precise shape and cured without machining, and labor and scrap can be reduced.

  As a result of the cost savings afforded by the electrical device of the present invention, industrial electrochemical processes that are currently not cost competitive with other industrial processes such as chlorination, ozonation and coagulation. Can be used economically.

  The electric device of the present invention is preferably a battery including two or more batteries, or a capacitor (particularly an electrolytic capacitor). When the electrical device is a fuel cell, the device includes at least one bipolar plate and an inlet and an outlet that control the flow of oxygen and hydrogen through the cell.

  The separator of the present invention has a single flow field. This is useful as a current collector, particularly in fuel cells. Bipolar plates are flat, gas impermeable, conductive separators between individual fuel cells in a stacked structure. Bipolar plates have flow fields on both sides. The flow field is preferably at least one passage machined or molded into the plate. The flow field is suitable for carrying fuel (usually hydrogen) on one side and oxidant on the other side from the entry point to the exit point in the fuel cell.

  The electrolyte means of the electrical device of the present invention is optionally in the form of an electrolyte or arranged to receive the electrolyte. For example, the electrolyte means may be in the form of a conduit through which the electrolyte can flow as the battery operates, or the electrolyte means may be in the form of a container that can contain the electrolyte at least when the battery operates. .

  The present invention also provides the use of carbon-doped, ester-cured salt-containing alkaline resole resins as electrodes.

  The present invention also provides the use of a conductive ester-cured salt-containing alkaline resole resin or composition as an electromagnetic shielding material or to prevent electrostatic discharge at a location. Examples of applications of the resin used in the present invention as an electromagnetic shielding material include electronic products such as computers, cash registers, mobile phones, other daily electronic devices, housings, electronic components, or electrostatic discharge. Examples include antistatic packaging materials used for fines, such as foods, that can cause a dust explosion.

  The present invention further provides a method of suppressing electromagnetic interference in a product, comprising shielding the product with a conductive ester-cured salt-containing alkaline resole resin or composition. This shielding preferably involves providing the product with a housing constructed of at least partially conductive ester-cured salt-containing alkaline resole resin or composition. The product may be an electrical or electronic product.

  The present invention also provides a method for preventing electrostatic discharge at any location, comprising providing the location with a conductive ester-cured salt-containing alkaline resole resin or composition. Suitable locations are packaging for fines or electronic devices or components, such as microchips or printed circuit boards, or for floor coverings, gas meter parts, water pump seals or self-lubricating bearings, or electrostatic discharge It may be a workbench or similar location that operates or processes sensitive devices or parts.

（式中、Ｒ^１は、直鎖状または分岐鎖状の、所望により不飽和の、１〜８個の炭素原子（好ましくは１〜４個の炭素原子、より好ましくは１〜２個の炭素原子）を含み、所望によりハロゲン原子（好ましくは塩素）またはヒドロキシ基により置換されたアルキル基、ハロゲン原子（好ましくは塩素）、ヒドロキシ基、および／またはフェニルまたはベンジル基（所望によりヒドロキシ基および／または直鎖状または分岐鎖状の、１〜８個の炭素原子（好ましくは１〜４個の炭素原子、より好ましくは１〜２個の炭素原子）を含み、所望によりハロゲン原子（好ましくは塩素）またはヒドロキシ基により置換されたアルキル基により置換されている）であり、
Ｍは、水素イオンと少なくとも一種の他の陽イオン（好ましくは、少なくとも一種の他の陽イオンは、アルカリ金属陽イオン（好ましくはナトリウム、リチウムまたはカリウム）、アルカリ土類金属陽イオン（好ましくはバリウム、マグネシウムまたはカルシウム）、および／またはＮ（Ｒ^２）_４ ^＋イオン（ここで各Ｒ^２は、同一であるか、または異なるものであって、水素または直鎖状または分岐鎖状の、１〜４個の炭素原子を含むアルキル基）である）の混合物であり、水素イオンと少なくとも一種の他の陽イオンのモル比は、ｐＨが７を超えるのに十分であり、好ましくは２：１〜１：１であり、
ｎは０〜２である）
のアルカリ性化合物の反応生成物である。 The ester-cured salt-containing alkaline phenolic resole resin doped with a conductive material is preferably a reaction product of an ester curing agent, a phenolic resole and a base. The phenolic resole is preferably a phenol-reactive aldehyde and a formula

Wherein R ¹ is linear or branched, optionally unsaturated, 1 to 8 carbon atoms (preferably 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms. An alkyl group optionally containing a halogen atom (preferably chlorine) or a hydroxy group, a halogen atom (preferably chlorine), a hydroxy group, and / or a phenyl or benzyl group (optionally a hydroxy group and / or Linear or branched, containing 1 to 8 carbon atoms (preferably 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms), optionally halogen atom (preferably chlorine) Or an alkyl group substituted by a hydroxy group)
M is a hydrogen ion and at least one other cation (preferably at least one other cation is an alkali metal cation (preferably sodium, lithium or potassium), an alkaline earth metal cation (preferably barium). , Magnesium or calcium), and / or N (R ² ) ₄ ⁺ ions, where each R ² is the same or different and is hydrogen or linear or branched, 1 to And a molar ratio of hydrogen ion to at least one other cation is sufficient for the pH to exceed 7, preferably 2: 1 to 1: 1
n is 0-2)
It is a reaction product of an alkaline compound.

  Examples of suitable compounds of formula (I) are salts of phenol itself, substituted phenols such as salts of alkylated phenols, halogenated phenols and polyhydric phenols, and hydroxy-substituted polynuclear aromatic compounds. However, it is not limited to these. Examples of alkylated phenols are methylphenol (also called cresol), dimethylphenol (also called xylenol), 2-ethylphenol, pentylphenol and tert-butylphenol. Examples of halogenated phenols are chlorophenol and bromophenol. Examples of polyphenols include 1,3-benzenediol (also called resorcinol), 1,2-benzenediol (also called pyrocatechol), 1,4-benzenediol (also called hydroquinone), 1,2,3 -Benzenetriol (also called pyrogallol), 1,3,5-benzenetriol and 4-tert-butyl-1,2-benzenediol (also called tert-butylcatechol). Examples of hydroxy substituted polynuclear aromatic compounds include 4,4'-isopropylidene bisphenol (also referred to as bisphenol A), 4,4'-methylidene bisphenol (also referred to as bisphenol F) and naphthol.

  Salts of compounds formed by condensation reactions of two or more compounds of formula (I) with one or more molecules of a phenol-reactive aldehyde are suitable for use in ester-cured alkaline resole resins. Examples include resinous reaction products of phenol itself, salts of substituted phenols such as alkylated phenols, halogenated phenols and polyhydroxyphenols, and hydroxy-substituted polycyclic aromatic compounds. It is not limited to. In addition, mixtures of aldehyde-reactive phenols, such as those obtained from coal tar fractionation, depolymerized lignin and cashew nut shell liquid can be used as all or part of the resol component.

The phenol-reactive aldehyde used to react with the compound of formula (I) to form an alkaline phenolic resole is preferably of the formula:
RCHO (II)
Wherein R contains a hydrogen atom or a straight or branched chain of 1 to 8 (preferably 1 to 4, more preferably 1 to 2, most preferably 1) carbon atoms. Represents an alkyl group)
Or a precursor of a compound of formula (II).

  Examples of suitable aldehydes are formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, n-valeraldehyde, caproaldehyde. Suitable compounds for use as precursors for compounds of formula (II) include compounds that decompose to formaldehyde, such as paraformaldehyde, trioxane, furfural, hexamethylenetriamine, acetals that release formaldehyde upon heating, and benzaldehyde. .

  The aldehyde is preferably reacted with the compound of (I) in a ratio of 1: 1 to 1: 3, preferably 1: 1.2 to 1: 3, more preferably 1: 1.5 to 1: 3.

Certain alkali M (OH) _x (where M is a cation as defined above and represents a non-hydrogen cation and x represents 1 or 2), such as calcium hydroxide, is not It is not soluble. These compounds can also be used by dehydrating the resin and using the ester as a solvent for the resole. An alkali insoluble in water can be dispersed in the resin to form a paste. In that case, a polar solvent (eg water) is required to initiate the reaction.

The ester curing agent used for curing the alkaline phenolic resole resin is preferably of the formula:
R ³ COOR ⁴ (III)
Where
R ³ contains a hydrogen atom or a linear or branched chain of 1 to 8 carbon atoms (preferably 1 to 4, more preferably 1 to 2 carbon atoms), and optionally a halogen atom Represents an alkyl group substituted by
R ⁴ is linear or branched and contains 1 to 8 carbon atoms (preferably 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms), optionally one or more Alkyl groups substituted by hydroxy and / or R ³ COO groups, or optionally linear or branched, optionally unsaturated, 1 to 8 carbon atoms (preferably 1 to 4 carbon atoms) An alkyl group, preferably a halogen atom (preferably chlorine), a hydroxy group, and / or a phenyl or benzyl group (optionally a hydroxy group and And / or a linear or branched alkyl group containing 1 to 8 carbon atoms (preferably 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms). R ³ represents a chemical bond with R ⁴ and R ⁴ represents a linear or branched 2-10 carbon atom (preferably Represents an alkyl group containing 2 to 4 carbon atoms).

  Ester curing agents for alkaline resole resins must be reactive with alkali so as to form salts in the cured resin. Reactive esters include, but are not limited to, carboxylic esters, polyhydric alcohol esters, lactones and carbonates, phenolic esters and resole esters. Examples of reactive carboxylic acid esters are methyl formate and ethyl formate. Examples of reactive polyhydric alcohol esters that can be used as curing agents for resins include glycerol triacetate and ethylene glycol diacetate. Examples of reactive carbonates include cyclic carbonates such as propylene carbonate and ethylene carbonate. Examples of reactive lactones are propiolactone, butyrolactone, valerolactone and caprolactone. Examples of reactive phenolic esters are phenyl acetate and resorcinol diacetate. An example of a reactive resole ester is 2,4,6-tris-acetoxymethylphenyl acetate. Mixtures of esters, such as propylene carbonate and triacetin, can be used to vary the cure rate.

The rate of cure of the resole by the ester is mainly determined by the acidity of the conjugate acid, for example the acidity of formic acid is greater than that of acetic acid, so that ethyl formate (R ³ = H) is better than ethyl acetate (R ³ = CH ₃ ). , Reacts about 1000 times faster. The gel times that can be achieved using each ester also show similar order differences. The extent to which the carbon chain length of the alcohol (R4) affects the saponification rate and gel time is smaller, with each additional carbon the saponification rate decreases and the gel time increases. It has also been found that as the chain length and / or branching of R ³ and R ⁴ increases, the miscibility of the resin and ester decreases. Good compatibility between the ester and the resin is essential for the curing reaction to proceed. Thus, the choice of ester curing agent determines the rate of cure of the reaction, and also determines the carboxylate ions formed during the reaction, and ultimately the salts contained in the polymer matrix that affect the properties of the electrode. Is clear.

  The base used in the reaction for forming the ester-cured salt-containing alkaline phenolic resole resin used in the present invention is preferably an alkaline compound capable of forming a conductive salt soluble in the resin used in the present invention. is there. Examples of suitable bases are hydroxides or oxides of alkali or alkaline earth metals or ammonia, such as lithium, sodium, potassium, magnesium, calcium, barium or ammonia.

  The ester-cured salt-containing alkaline phenolic resole resin used in the present invention is preferably made from a resole resin, an ester curing agent, one or more bases, and optionally a polar solvent. Their synthetic methods are well known to those skilled in the art and are described in DE-C-10656605, DE-C-11171606, JP-A49-16793 and JP-A50-130627. According to these documents, a highly alkaline phenolic resole resin in an aqueous solution can be cured by contacting the resin with an ester in liquid or gaseous form at room temperature by reaction with an organic ester. The ester-cured alkaline phenolic resole resin containing conductive alkali salt used in the present invention is in a dry or anhydrous form, as desired, depending on the specific properties required.

  Another feature of the ester-cured alkaline phenolic resin is that it is aqueous and can be diluted with water, unlike most common thermosetting polymer systems. The polymerization reaction is not affected by adding an ester curing agent to the resin diluted with water, and the curing of the polymer proceeds at a slow rate. However, by using a faster curing ester, the speed of the curing process can be increased to the desired speed. The main advantage that the properties that can be diluted with water give to the ester-cured phenolic resin mixture doped with the conductive material is that the electrode material wets the carbon or graphite powder or flakes and has a high content of conductive material And a highly conductive electrode can be formed from the material. Upon room temperature curing, the added water evaporates from the formed electrode material, resulting in a hard, solid, highly conductive material, low water content, conductive material doped, ester cured phenolic polymer. It is done.

  The controlled addition of water to the resin / carbon mixture is important for processing as it can change the consistency of the mixture and adapt it to the room temperature injection molding, pouring and casting techniques used. When highly water is added, the mixture can be increased by including thickeners such as starch or starch derivatives, cellulose or cellulose derivatives, natural gums such as gum arabic or guar gum, or synthetic thickeners such as polyamide or polyacrylate. The consistency can be adjusted effectively.

  The resin used in the present invention optionally contains a plasticizer in order to increase the flexibility of the resin. Clearly, flexible resins are useful for certain applications. The plasticizer is preferably inert, compatible with alkali, non-volatile and / or liquid. Preferably, the plasticizer is soluble in the resin and / or ester hardener. The level of plasticizer is determined by the application requirements and is limited by the effect on the conductivity of the cured electrode material. Examples of plasticizers are excess ester hardeners, polyvinyl acetate and / or polyethylene glycol.

  The ester-cured phenolic resin can be foamed using a foaming agent in the resin formulation to form a three-dimensional structure. Examples of blowing agents include low boiling solvents with low water miscibility, such as trichloromonofluoromethane (CFC-11), hydrogenated chloroperfluorocarbons (referred to as "HCFC"), partially hydrogenated There are perfluorinated hydrocarbons (referred to as “HFC”), hydrocarbons such as iso-pentane and cyclopentane. The foaming agent is used in this application not only to produce an insulating foam, but to form a three-dimensional open cell structure. Accordingly, the foaming agent is lost during the curing process and can be recovered and recycled after forming a three-dimensional structure. Other blowing agents such as carbon dioxide and nitrogen can also be used.

  The present invention will be described with reference to the accompanying drawings, wherein FIGS. 1 and 2 show the results obtained from tests using the battery of the present invention having electrodes in the form of rotating cylinders.

  FIG. 3 shows an electrical device having a block of electrolyte 2 and having asymmetric electrodes 3a, 3b on both sides thereof. The asymmetric electrode includes electrical connection portions 4a and 4b, respectively. These electrodes are asymmetric electrodes in that one acts as a cathode and the other acts as an anode. The asymmetric electrode is made of, for example, a resin manufactured according to Example 2.

  FIG. 4 shows an electrical device in the form of a fuel cell 10 having, for example, a hydrogen inlet 30 and outlet 35 and an oxygen inlet 40 and outlet 45. The fuel cell 10 in this example has electrodes 20 and 25 and a bipolar plate 15. Bipolar plate 15 is shown in more detail in FIG. 5 as having grooves 50 on its surface. The opposite surface of the plate 15 also has a groove 50. A modification of the bipolar plate 15 is a separator plate having grooves 50 only on one side.

  The following example illustrates the method of manufacturing the electrode used in the present invention. The benefits of the present invention are also demonstrated. In these examples, the materials used are conventional alkaline phenolic resole (resin A), neutral resole resin (B), butyrolactone (ester), triacetin (ester), and graphite, nickel powder and copper powder (conductive) Reinforcing agent).

Example 1
This example illustrates the preparation of an alkaline phenol-formaldehyde resin where the molar ratio of formaldehyde to phenol is 2.0: 1 and the molar ratio of sodium hydroxide to phenol is 0.65: 1. Phenol (5.0 mol) and sodium hydroxide (0.1 mol) were placed in a reaction vessel and 50% formalin (3.0 mol) was added while maintaining the temperature at 65 ° C. The temperature was raised to 80 ° C. and maintained at 80 ° C. while a second charge of 50% formalin (7.0 mol) was gradually added over 30 minutes. The mixture was then maintained at 80 ° C. for 60 minutes before 50% sodium hydroxide solution (3.15 moles) was added to maintain the temperature at 80 ° C. The resin was concentrated at 80 ° C. to a viscosity of 400 cP.

Example 2
A carbon-doped, ester-cured resole resin used as an electrode was prepared by mixing 50 g of resin A with 100 g of graphite, 50 g of water and 10 g of butyrolactone in a paper cup. A portion of the mixture was poured into a latex mold and allowed to cure. Gel time was recorded from the time the mixture was placed in the cup.

Example 3
The cast sample from Example 2 was allowed to stand at room temperature for 24 hours before measuring the conductivity using a Como DT3800 Digital Multimeter. The resistance of the sample was measured as 9 ohms at 20 ° C.

Example 4
This example demonstrates how the resin produced in Example 2 functions as an electrode material for efficiently recovering metal ions from solution. The resin was processed into a cylinder and the epoxy resin was fixed to the rotating disk electrode by using silver to produce a rotating cylinder electrode RCE.

  This RCE was then used in various experiments, primarily to show how efficient the electrode material was under the test conditions. First, this electrode was used to obtain current-potential curves for 1 mmol of Cu2 + and Cd2 + deposition at pH 2 in 0.5 MH 2 SO 4.

  FIG. 1 shows five curves giving results for five different rotational speeds. The rotation speed for each curve is as follows in order. The first curve (bottom on the graph and reaching -0.02 mA) is measured at 200 rpm, the second curve is measured at 400 rpm, the third curve is measured at 800 rpm, and the fourth curve is Measurement was performed at 1600 rpm, and the fifth curve was measured at 3200 rpm.

  Each curve shows a change in current when the potential is changed. In this scan, the potential is changed (at 1 mVs-1) and the current is recorded. The intensity of the current depends on the reaction taking place (in this case copper and cadmium deposition). The initial curve (range -150 to -750 mV) is caused by copper deposition on the electrode surface, cadmium begins to deposit at -750 to 1050 mV, and hydrogen evolution (as a secondary reaction) after -1050 mV. Start.

  From FIG. 1, it is clear that the resin of Example 2 functions as an electrode when copper and cadmium are removed from the mixed solution.

Example 5
In this example, the electrode of Example 2 was used to collect copper from the solution for 2 hours, samples were taken at intervals, and the amount of copper in the solution was analyzed.

  First, from FIG. 2, as expected, the rate at which copper is removed from the solution increases as the potential increases during the experiment. In addition, when the electrode is already coated (pretreated) with copper at the same potential (−0.43 V), the speed at which copper is removed is also the speed when the experiment is performed at −0.60 V. Increases to a speed close to. It can be seen that pretreatment of the electrode or increasing the potential during the experiment further increases the removal rate by 10%. Over the 2 hour period, the amount of copper removed is just less than 50%.

  These results indicate that this polymeric material can be used to remove metal ions from water.

Example 6
Carbon doped ester cured phenolic resin electrode materials were prepared from graphite grade carbon of various particle size distributions.

  Sample A: Graphite grade KL96 / 97 (96-97% carbon flake graphite, ground to 20-25 microns d50, supplied by Branwell, UK) 100 g resin 40 g (from Example 1), water 75 g, guar gum thickening Mixed with 0.6 g of agent and 8 g of triacetin curing agent. This mixture was mixed in Kenwood Chef for 2 minutes, then poured into a 10 ml cylindrical mold and allowed to cure at room temperature. After 15 minutes, the sample was removed from the mold. One hour after removal from the mold, resistivity measurements were started and continued for several days.

Sample B: Similar to A using a coarser grade of graphite grade 2300 d50 36-42 microns.

Sample C: Similar to A using flake grade graphite KFL96 / 97 “small flakes” (typically 35-40%> 100 microns, 40% <75 microns, ie having an average particle size of 80-90 microns) What

  Table 1 shows that all samples have a high initial resistance and that as the cure proceeds, the resistance rapidly decreases over the next few hours and reaches <10 ohm cm.

Example 7
Carbon-doped ester-cured phenolic resin electrode material was prepared from carbon graphite mixed with other conductive fillers.

  Sample D: 40 g of graphite grade 2300 supplied from Branwell, UK was mixed with 80 g of copper particles and added to 20 g of resin (from Example 1). 4 g of triacetin hardener was added and the mixture was mixed in the cup for 2 minutes, then poured into a 10 ml cylindrical mold and allowed to cure at room temperature. After 15 minutes, the sample was removed from the mold. One hour after removal from the mold, resistivity measurements were started and continued for several days.

  Sample E: Nickel particles 36 to 42 microns were used, and the same as D was used.

  Table 2 shows that all samples give high initial resistance and that as the cure progresses, the resistance drops rapidly over the next few hours and reaches <20 ohm cm.

Example 8
Preparation of carbon-doped, ester-cured phenolic solid foam structure Carbon-doped, ester-cured phenolic solid foam structure, 50 parts of phenolic foam resin IDP292 supplied by Borden Chemical UK Ltd, from Dow Corning Prepared by premixing with 2 parts of the supplied DC193 silicone oil. Then 100 parts of KL96 / 97 graphite powder and 50 parts of water were mixed with this resin until a smooth mixture was achieved. Using a high speed laboratory mixer, 10 parts of HCFC 14lb blowing agent was mixed into the resin mixture to obtain a smooth emulsion. To initiate the reaction, 15 parts of butyrolactone hardener was mixed into the emulsion using a high speed mixer. After mixing for 10 seconds, the foam mixture was transferred to a plastic mold and immediately placed in a 50 ° C. oven where the foam was expanded and allowed to cure overnight. When the foam was cut, a fine foam structure with open cell density of 265 kgm-3 was measured. After 24 hours, a resistance of 1 K ohm cm was measured.

Example 9
Resin B Preparation of Neutral Resol Phenol (1 mol) and sodium hydroxide (0.004 mol) were placed in a reaction vessel and 50% formalin (0.6 mol) was added while maintaining the temperature at 50 ° C. The temperature was then raised to 80 ° C. The temperature was maintained at 80 ° C. while a second charge of 50% formalin (1.0 mole) was gradually added over 30 minutes. The mixture was then maintained at 80 ° C. for 45 minutes. The pH was adjusted to 6.0 ± 0.2 with p-toluenesulfonic acid solution. The resin was cooled to 60 ° C. and then dehydrated by vacuum distillation until a viscosity of 200 cP was reached. The obtained resin had a resin solid content of 72%.

Example 10
An ester-cured resol resin used as an electrode was prepared by mixing 50 g of resin A with 10 g of butyrolactone in a paper cup. A portion of the mixture was poured into a latex mold and allowed to cure. Gel time was recorded from the time the mixture was placed in the cup.

Example 11
In Example 11, 50 g of Resin B was cooled below 10 ° C. (to suppress heat generation) and mixed with 2 g of acid.

  The cast samples from Examples 10 and 11 were allowed to stand at room temperature for 24 hours before measuring resistance using a Como DT3800 Digital Multimeter.

  Table 3 shows the result of the resistance value.

  Examples 10 and 11 show the conductivity induced by alkali metal salt formation in an ester cured phenolic resole reaction (Example 10) compared to an acid cured resole composition (Example 11).

Example 12
100 g of graphite grade 2369 (98% carbon flake graphite, 80% min.> 180 microns ground, supplied by Branwell, UK) was mixed with 50 g of Resin A and 10 g of triacetin curing agent. This mixture was mixed in Kenwood Chef for 2 minutes, then poured into a 20 ml cylindrical mold, pressed using a hydraulic press, released from the mold and allowed to cure at room temperature. Samples were prepared under a range of pressures. Resistivity measurement was started 24 hours after removal from the mold.

Example 13
This example demonstrates how the carbon electrode bonded with the ester cured phenolic resin prepared in Example 2 functions as an electrode material (in this case an anode). This may be useful, for example, for reducing Cl- ions to chlorine gas. The electrode composition was processed into a cylinder and anodically polarized in saturated saline solution at 50 mAcm-3 for 65 hours. The anode weight at the start of polarization was 12.5 g. After 65 hours, this weight was measured at 12.8 g, indicating good anode stability.

  A standard graphite rod was anodically polarized in saturated saline for the same time and found to be significantly eroded compared to a carbon electrode bonded with an ester-cured phenolic resin. This is illustrated by comparing the electrode sizes shown in FIG. In FIG. 6, the right electrode is a standard graphite rod after 65 hours of polarization. It can be seen that it is significantly smaller than the electrode, shown on the left, made according to the invention and also subjected to a 65 hour polarization treatment.

Figure 6 shows plots for copper and cadmium deposition at various rotational speeds of a rotating cylinder. The change of the impairment rate in various electric potentials is shown. It is sectional drawing which shows the 1st embodiment of the electric apparatus of this invention typically. It is a top view which shows the 2nd embodiment of the electric apparatus of this invention typically. It is a top view which shows typically the bipolar plate of this invention. FIG. 6 is a photograph showing significant wear after polarization of a graphite rod anode (shown on the right) for 65 hours in saline compared to a carbon anode bonded with an ester-cured phenolic resin (shown on the left).

Claims (13)

  An electrode comprising an alkaline phenolic resole resin doped with a conductive material, containing a conductive alkaline salt and ester-cured.   The electrode according to claim 1, wherein a weight ratio of the resin to the conductive material is 0.001 to 100: 1.   The electrode according to claim 1 or 2, wherein the conductive material comprises carbon and / or non-carbon conductive filler.   The carbon is in the form of graphite or amorphous carbon and / or the non-carbon conductive filler is in the form of a metal, metal oxide, and / or metal-coated graphite, and / or glass. Item 4. The electrode according to Item 3.   The electrode according to any one of claims 1 to 4, wherein the resin is a reaction product of an ester curing agent, a phenolic resole and a base. The phenolic resol is a phenol-reactive aldehyde and a formula:

(In the formula, R ¹ represents a linear or branched chain having 1 to 8 carbon atoms including an alkyl group substituted by a halogen atom or a hydroxy group, a halogen atom, hydroxy group, and / or phenyl or A benzyl group,
M is a mixture of hydrogen ions and at least one other cation, and the molar ratio of hydrogen ions to the at least one other cation is sufficient for the pH to exceed 7, 2: 1 : 1
n is 0-2)
The electrode according to claim 5, which is a reaction product of an alkaline compound. The phenol reactive aldehyde has the formula:
RCHO (II)
(In the formula, R represents a hydrogen atom or a linear or branched alkyl group containing 1 to 8 carbon atoms)
The electrode according to claim 6, which is a precursor of a compound of formula (II) or a compound of formula (II).   The electrode according to claim 6 or 7, wherein the phenol-reactive aldehyde reacts with the compound of formula (I) in a ratio of 1: 1 to 1: 3. The ester curing agent has the formula:
R ³ COOR ⁴ (III)
(In the formula, R ³ represents a hydrogen atom or an alkyl group substituted with a halogen atom containing 1 to 8 carbon atoms which are linear or branched,
R ⁴ represents a linear or branched, 1-8 including alkyl group carbon atoms or a linear or branched 1-8 alkyl group containing a carbon atom, a halogen atom, represent a hydroxy group, and / or phenyl or phenyl group substituted by a benzyl group, or R ³ represents a chemical bond with R ^4, R ⁴ represents a linear or branched, 2-10 Represents an alkyl group containing one carbon atom)
The electrode according to any one of claims 5 to 8, comprising:   The electrode according to claim 1, wherein the resin contains a plasticizer to increase the flexibility of the resin.   Use as an electrode in a three-dimensional form in which an alkaline phenolic resole resin containing a conductive alkali salt doped with a conductive material and ester-cured is foamed.   Use of an alkaline phenolic resole resin doped with a conductive material, containing a conductive alkali salt and ester-cured, as an electrode. The use according to claim 11 or 12 , wherein the ester-cured salt-containing alkaline resole resin is as defined in any one of claims 1 to 10.

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