JP6349945B2 - Composite particle for capacitor electrode composition layer for lead storage battery, and method for producing capacitor electrode composition layer for lead storage battery - Google Patents

Description

  The present invention relates to a composite particle for a capacitor electrode composition layer for a lead storage battery used in a lead storage battery, a method for producing a capacitor electrode composition layer for a lead storage battery using the composite particle, and an electrode for a lead storage battery.

  Lead-acid batteries that use lead dioxide as the positive electrode active material, lead as the negative electrode active material, and sulfuric acid as the electrolyte are inexpensive and suitable for high-current discharge in many industries compared to other secondary batteries. Even today, the importance of high-capacity secondary batteries such as lithium-ion secondary batteries is prominent, and their importance has not been lost.

In recent years, a technique using activated carbon has been reported regarding the improvement of short-time large current discharge characteristics, which is an advantage of a lead-acid battery, and the improvement of cycle characteristics with a large discharge depth, which is a disadvantage.
For example, increasing the charging speed of a lead-acid battery or providing a capacitor electrode composition layer to improve the depth of discharge has been performed.

  In Patent Document 1, a capacitor electrode composition layer is formed by coating a slurry for forming a capacitor electrode composition layer on a lead electrode. In Patent Document 2, a capacitor electrode composition layer is formed by dry molding using composite particles containing a capacitor electrode active material such as activated carbon and a binder.

JP 2011-71110 A JP 2010-192417 A

  However, when the capacitor electrode composition layer is formed by applying and drying the slurry as in Patent Document 1, migration of the binder occurs, and thus the resistance of the obtained lead storage battery increases. Further, when the capacitor electrode composition layer is formed by dry molding as in Patent Document 2, the strength of the obtained capacitor electrode composition layer is required.

  An object of the present invention is to provide a composite electrode for a capacitor electrode composition layer for a lead storage battery capable of obtaining a lead storage battery having a low strength and a capacitor electrode composition layer for a lead storage battery having excellent strength, and for a lead storage battery using the composite particle It is providing the manufacturing method of a capacitor electrode composition layer, and the electrode for lead acid batteries.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by incorporating a predetermined amount of water in the composite particles, and have completed the present invention.

That is, according to the present invention,
(1) Composite particles for a capacitor electrode composition layer for a lead storage battery containing activated carbon, a conductive material, a binder, and water, wherein the binder is 2 wt. % Or more and 20 wt. %, And the water is 2 wt. % Or more and 40 wt. Composite particles for a capacitor electrode composition layer for a lead storage battery having a volume average particle size of 50 μm or more and less than 200 μm,
(2) A lead-acid battery capacitor electrode composition layer comprising a step of supplying the composite particles for a lead-acid battery capacitor electrode composition layer according to (1) onto a support and press-molding with a pair of press rolls. Production method,
(3) The method for producing a capacitor electrode composition layer for a lead storage battery according to (2), wherein at least one of the press rolls constituting the pair of press rolls is a rubber roll,
(4) The method for producing a capacitor electrode composition layer for a lead storage battery according to (3), wherein the rubber constituting the rubber roll has a hardness of 10 ° or more and less than 95 °,
(5) A lead-acid battery electrode comprising the lead-acid battery capacitor electrode composition layer produced by the method for producing a lead-acid battery capacitor electrode composition layer according to any one of (2) to (4) is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the capacitor electrode composition layer for lead storage batteries which can obtain the capacitor electrode composition layer excellent in intensity | strength, and the lead storage battery with small resistance, the capacitor electrode composition for lead storage batteries using this composite particle The manufacturing method of a physical layer and the electrode for lead acid batteries can be provided.

It is the schematic which shows the aspect of the manufacturing process of the capacitor layer of this invention.

  Hereinafter, composite particles for a capacitor electrode composition layer for a lead storage battery according to an embodiment of the present invention will be described with reference to the drawings. The composite particle for a capacitor electrode composition layer for a lead storage battery according to the present invention is a composite particle for a capacitor electrode composition layer for a lead storage battery containing activated carbon, a conductive material, a binder, and water, wherein the binder is the activated carbon. 2 wt. % Or more and 20 wt. %, And the water is 2 wt. % Or more and 40 wt. The volume average particle diameter is 50 μm or more and less than 200 μm.

(Activated carbon)
The activated carbon used for the composite particles for the capacitor electrode composition layer for lead-acid batteries of the present invention (hereinafter sometimes referred to as “composite particles”) has a function as a capacitor electrode active material that transfers electrons in the electrode.

  Specifically, as the activated carbon, it is preferable to use activated carbon made of phenol resin, rayon, acrylonitrile resin, petroleum pitch, coconut shell, or the like, and from the viewpoint of adhesion to the lead plate, petroleum pitch is used as a raw material. More preferably, activated carbon is used.

  The volume average particle diameter of the activated carbon is preferably 0.1 to 100 μm, more preferably 1 to 50 μm, and still more preferably 5 to 20 μm.

The specific surface area of the activated carbon is preferably 30 m ² / g or more, more preferably 500~5,000m ² / g, more preferably 1,000~3,000m ² / g. Since the density of the obtained capacitor electrode composition layer for a lead storage battery tends to decrease as the specific surface area of the activated carbon increases, a capacitor layer having a desired density can be obtained by appropriately selecting the activated carbon.

(Conductive material)
The conductive material used in the present invention is composed of an allotrope of particulate carbon that has conductivity and does not have pores that can form an electric double layer. Specifically, furnace black, acetylene black, and ketjen And carbon black such as black (registered trademark of Akzo Nobel Chemicals Besloten Fennaut Shap). Among these, acetylene black and ketjen black are preferable.

  The volume average particle diameter of the conductive material used in the present invention is preferably smaller than the volume average particle diameter of activated carbon, and preferably 0.001 to 10 μm, more preferably from the viewpoint of obtaining high conductivity with a smaller amount of use. Is 0.005 to 5 μm, more preferably 0.01 to 1 μm. These conductive materials can be used alone or in combination of two or more.

  The amount of the conductive material is preferably 0.1 wt. % Or more and 20 wt. %, More preferably 0.5 wt. % Or more and 20 wt. %, More preferably 2 wt. % Or more and 20 wt. %.

  When there is too much quantity of the electrically conductive material in a composite particle, the capacity | capacitance of the capacitor electrode composition layer for lead storage batteries obtained will fall. Moreover, when there is too little quantity of the electrically conductive material in a composite particle, the resistance of the capacitor electrode composition layer for lead storage batteries obtained will increase.

(Binder)
The binding material used in the present invention is not particularly limited as long as it is a compound capable of binding activated carbon or a conductive material to each other. A suitable binder is a dispersion type binder having a property of being dispersed in a solvent. Examples of the dispersion-type binder include polymer compounds such as a fluoropolymer, a diene polymer, an acrylic polymer, a polyimide, a polyamide, and a polyurethane polymer, and a diene polymer and an acrylic polymer are preferable.

  The diene polymer is a homopolymer of a conjugated diene or a copolymer obtained by polymerizing a monomer mixture containing a conjugated diene, or a hydrogenated product thereof. Specific examples of the diene polymer include conjugated diene homopolymers such as polybutadiene and polyisoprene; aromatic vinyl / conjugated diene copolymers such as carboxy-modified styrene / butadiene copolymer (SBR); acrylonitrile -Vinyl cyanide * conjugated diene copolymers, such as a butadiene copolymer (NBR); Hydrogenated SBR, hydrogenated NBR, etc. are mentioned.

  The acrylic polymer is a copolymer obtained by polymerizing a homopolymer of acrylic ester or methacrylic ester or a monomer mixture containing a monomer copolymerizable therewith. Examples of the copolymerizable monomer include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, and fumaric acid; two or more carbons such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and trimethylolpropane triacrylate. -Carboxylic acid ester having a carbon double bond; styrene, chlorostyrene, vinyl toluene, t-butyl styrene, vinyl benzoic acid, vinyl benzoate methyl, vinyl naphthalene, chloromethyl styrene, hydroxymethyl styrene, α-methyl styrene, Styrene monomers such as divinylbenzene; Amide monomers such as acrylamide, N-methylolacrylamide, and acrylamide-2-methylpropane sulfonic acid; α, β-defect such as acrylonitrile and methacrylonitrile Japanese nitrile compounds; olefins such as ethylene and propylene; diene monomers such as butadiene and isoprene; monomers containing halogen atoms such as vinyl chloride and vinylidene chloride; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate Vinyl esters such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, etc .; Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, hexyl vinyl ketone, isopropenyl vinyl ketone; N-vinyl pyrrolidone, vinyl Heterocycle-containing vinyl compounds such as pyridine and vinylimidazole; and hydroxyalkyl group-containing compounds such as β-hydroxyethyl acrylate and β-hydroxyethyl methacrylate.

  Among these, it is preferable to use a diene polymer from the viewpoint of strength when dry-molding into composite particles together with activated carbon and a conductive material, and an acrylonitrile-butadiene copolymer (hereinafter referred to as “NBR”). Is more preferable. The ratio of the 1,3-butadiene monomer unit in the binder when the acrylonitrile-butadiene copolymer is used is preferably 40 to 75% by weight, and preferably 45 to 75% by weight. Is more preferable. Further, when the acrylonitrile-butadiene copolymer is used, the ratio of the acrylonitrile monomer unit in the binder is preferably 20 to 60% by weight, and more preferably 20 to 45% by weight.

  The acrylonitrile-butadiene copolymer preferably further contains monomer units of the aforementioned unsaturated carboxylic acids such as acrylic acid and methacrylic acid in addition to 1,3-butadiene and acrylonitrile. As unsaturated carboxylic acids, methacrylic acid is preferable. In this case, the lower limit of the ratio of the unsaturated carboxylic acid monomer in the binder is preferably 3% by weight or more, more preferably 5% by weight or more, and the upper limit is 39% by weight. Or less, more preferably 35% by weight or less.

  The glass transition temperature (hereinafter referred to as “Tg”) of the binder used in the present invention is preferably −40 to + 40 ° C., more preferably −30 to + 30 ° C. If the Tg of the binder is too high, the obtained capacitor electrode composition layer for lead storage battery is inferior in flexibility, and if the Tg of the binder is too low, formation of the capacitor electrode composition layer for lead storage battery becomes difficult. The binder may have a melting point.

The shape of the binder is most preferably particulate, for example, to improve binding, decrease the capacity of the lead-acid battery, and minimize the increase in resistance of the lead-acid battery electrode. Examples include a state in which the particles of the binder resin are dispersed in a solvent and a powder form obtained by drying such a dispersion.
The particle size of the binder is not particularly limited, but is preferably a volume average particle size of 100 to 500 nm.

  The method for producing the binder is not particularly limited, and a known polymerization method such as an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method or a solution polymerization method using a composition containing each monomer at a predetermined ratio is used. Can be adopted. Among these, it is preferable to produce by an emulsion polymerization method because the particle diameter of the binder is easy to control. In particular, an aqueous polymerization method using water as a main solvent is preferred.

  The amount of the binder was 2 wt.% Relative to the weight of the activated carbon in the composite particles. % Or more and 20 wt. %, Preferably 3 wt. % Or more and 20 wt. %, More preferably 4 wt. % Or more and 20 wt. %.

  When there is too much quantity of the binder in a composite particle, the resistance of the capacitor electrode composition layer for lead acid batteries obtained will increase. Moreover, when there is too little quantity of the electrically conductive material in composite particles, the intensity | strength of the capacitor electrode composition layer for lead storage batteries obtained will fall.

(water)
The amount of water contained in the composite particles of the present invention is 2 wt. % Or more and 40 wt. %, Preferably 3 wt. % Or more and 30 wt. %, More preferably 4 wt. % Or more and 25 wt. %.

  If the amount of water in the composite particles is too large, the fluidity of the composite particles deteriorates. Moreover, when there is too little quantity of the water in composite particle | grains, electrolyte solution will become difficult to osmose | permeate into the capacitor electrode composition layer for lead storage batteries obtained, and also the intensity | strength of this capacitor electrode composition layer for lead storage batteries will fall.

(Dispersant)
The composite particles of the present invention may contain a dispersant. Specific examples of the dispersant include cellulosic polymers such as carboxymethylcellulose, methylcellulose, ethylcellulose and hydroxypropylcellulose, and ammonium salts or alkali metal salts thereof; poly (meth) acrylates such as sodium poly (meth) acrylate Polyvinyl alcohol, modified polyvinyl alcohol, polyethylene oxide; polyvinyl pyrrolidone, polycarboxylic acid, oxidized starch, phosphate starch, casein, various modified starches, chitin, chitosan derivatives and the like. These dispersants can be used alone or in combination of two or more. Among these, a cellulose polymer is preferable, and carboxymethyl cellulose or an ammonium salt or an alkali metal salt thereof is particularly preferable.

  The amount of the dispersant in the composite particles is preferably 0.1 wt. % Or more and 20 wt. %, More preferably 0.5 wt. % Or more and 10 wt. %, More preferably 0.8 wt. % Or more and 5 wt. %.

(Method for producing capacitor electrode composition layer for lead-acid battery)
The capacitor electrode composition layer for lead-acid batteries (hereinafter sometimes referred to as “capacitor layer”) includes other components used as necessary, such as activated carbon, a conductive material, a binder, water, and a dispersant. Further, although the capacitor layer is provided on the support, the method of forming the capacitor layer on the support is not limited.

  As a method for forming the capacitor layer on the support, any method may be used that uses composite particles composed of other components such as activated carbon, a binder, a conductive material, water, and a dispersant as required. Although not particularly limited, a method (dry molding method) obtained by forming composite particles into a sheet on a support and roll forming as necessary is preferable from the viewpoint of increasing the capacity of the capacitor layer and reducing internal resistance.

(Preparation of composite particles)
When the capacitor layer is formed by a dry forming method, composite particles containing other components such as activated carbon, a conductive material, a binder, water, and a dispersant are used. By using the composite particles, the electrode strength of the obtained capacitor layer can be increased, or the internal resistance can be reduced. Here, the composite particles refer to particles in which a plurality of materials such as activated carbon, a conductive material, a binder, water, and other components such as a dispersant are integrated. Moreover, the composite particle which can be used suitably is manufactured by granulating using other components, such as activated carbon, an electrically conductive material, a binder, water, and a dispersing agent.

  The granulation method of the composite particles is not particularly limited, and is spray drying granulation method, rolling bed granulation method, compression granulation method, stirring granulation method, extrusion granulation method, crushing granulation method, fluidized bed It can be produced by a known granulation method such as a granulation method, a fluidized bed multifunctional granulation method, or a melt granulation method. Among these, since the desired composite particles can be easily obtained, the spray drying granulation method, the fluidized bed granulation method and the stirring type granulation method are preferable.

  In the spray drying granulation method, first, other components such as the activated carbon, the conductive material, the binder, and the dispersing agent described above are dispersed or dissolved in a solvent (water), and the activated carbon, the conductive material, the binder, and the dispersing agent are dispersed. A slurry in which other components such as the above are dispersed or dissolved is obtained.

  The solvent used for obtaining the slurry is usually water. Although not particularly limited, when the above dispersant is used, a solvent capable of dissolving the dispersant is preferably used. Moreover, in the range which does not impair the effect of this invention, you may use the mixed solvent of water and an organic solvent. Examples of the organic solvent include alkyl alcohols such as methyl alcohol, ethyl alcohol and propyl alcohol; alkyl ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran, dioxane and diglyme; diethylformamide, dimethylacetamide and N-methyl- Amides such as 2-pyrrolidone and dimethylimidazolidinone; sulfur solvents such as dimethyl sulfoxide and sulfolane; and the like. Among these, alcohols are preferable as the organic solvent. When water and an organic solvent having a lower boiling point than water are used in combination, the drying rate can be increased during spray drying. Further, the dispersibility of the binder or the solubility of the dispersant varies depending on the amount or type of the organic solvent used in combination with water. Thereby, the viscosity and fluidity | liquidity of a slurry can be adjusted and production efficiency can be improved.

  From the viewpoint of uniformly dispersing the binder, the amount of the solvent used when preparing the slurry is preferably 1 wt. % Or more and 50 wt. %, More preferably 5 wt. % Or more and 50 wt. %, More preferably 10 wt. % Or more and 30 wt. The amount is less than%.

  A method or procedure for dispersing or dissolving activated carbon, a conductive material, a binder, and other components such as a dispersant in a solvent (water) is not particularly limited. For example, activated carbon, a conductive material, a binder is added to the solvent (water). A method of adding and mixing a binder and a dispersant; after dissolving the dispersant in a solvent (water), a binder (for example, latex) dispersed in the solvent (water) is added and mixed, and finally Method of adding and mixing activated carbon and conductive material; adding and mixing activated carbon and conductive material to a binder dispersed in a solvent (water), adding a dispersant dissolved in a solvent to this mixture and mixing And the like. Examples of the mixing means include mixing equipment such as a ball mill, a sand mill, a bead mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, a homomixer, and a planetary mixer. The mixing is preferably performed at room temperature to 80 ° C. for 10 minutes to several hours.

  The viscosity of the slurry is preferably 10 to 3,000 mPa · s, more preferably 30 to 1,500 mPa · s, and further preferably 50 to 1,000 mPa · s at room temperature from the viewpoint of increasing the productivity of the composite particles. . The higher the viscosity of the slurry, the larger the spray droplets, and the larger the volume average particle diameter of the composite particles obtained.

  Next, the slurry obtained above is spray-dried and granulated to obtain composite particles. Spray drying is performed by spraying the slurry in hot air and drying. An atomizer is used as an apparatus for spraying the slurry. There are two types of atomizers: a rotating disk method and a pressure method. The rotating disk system is a system in which slurry is introduced almost at the center of a disk that rotates at a high speed, and the slurry is released out of the disk by the centrifugal force of the disk, and the slurry is atomized at that time. The rotational speed of the disk depends on the size of the disk, but is preferably 5,000 to 30,000 rpm, more preferably 15,000 to 30,000 rpm. The lower the rotational speed of the disk, the larger the spray droplets and the larger the volume average particle diameter of the resulting composite particles. Examples of the rotating disk type atomizer include a pin type and a vane type, and a pin type atomizer is preferable. A pin-type atomizer is a type of centrifugal spraying device that uses a spraying plate, and the spraying plate has a plurality of spraying rollers attached between upper and lower mounting discs in a substantially concentric manner along its periphery. It consists of The slurry is introduced from the center of the spray platen, adheres to the spraying roller by centrifugal force, moves outside the roller surface, and finally sprays away from the roller surface. On the other hand, the pressurization method is a method in which the slurry is pressurized and sprayed from a nozzle to be dried.

  The temperature of the slurry to be sprayed is usually room temperature, but may be heated to room temperature or higher. Moreover, the hot air temperature at the time of spray-drying becomes like this. Preferably it is 80-250 degreeC, More preferably, it is 100-200 degreeC. In spray drying, the method of blowing hot air is not particularly limited, for example, a method in which the hot air and the spray direction flow in the horizontal direction, a method in which the hot air is sprayed at the top of the drying tower and descends with the hot air, and the sprayed droplets and hot air are in countercurrent contact. And a system in which sprayed droplets first flow in parallel with hot air and then drop by gravity to make countercurrent contact.

  Composite particles are obtained by spray drying. The volume average particle diameter of the composite particles is 50 μm or more and less than 200 μm, preferably 60 μm or more and less than 180 μm. Here, the volume average particle diameter of the composite particles is a volume average particle diameter measured by pressurizing and spraying the composite particles with compressed air using a laser diffraction particle size distribution analyzer. When the volume average particle diameter of the composite particles is too large, the accuracy of the amount of the composite particles per unit area on the support deteriorates when the composite particles are supplied onto the support. On the other hand, if the volume average particle size of the composite particles is too small, the fluidity of the composite particles becomes insufficient.

  The composite particles are preferably spherical. Evaluation of whether the composite particles are spherical or not is a value calculated by (Ll−Ls) / {(Ls + Ll) / 2} where Ls is the short axis diameter of the composite particles and Ll is the long axis diameter. (Hereinafter referred to as “sphericity”). Here, the minor axis diameter Ls and the major axis diameter Ll are average values for 100 arbitrary composite particles measured from a photographic image obtained by observing the composite particles using a reflection electron microscope. The smaller this value, the closer the spherical composite particle is to a true sphere. The sphericity of the composite particles is preferably 20% or less, and more preferably 15% or less.

  Moreover, the agitation type granulation method and fluidized bed granulation method are methods in which a binder is sprayed on activated carbon that has been forced to flow to perform granulation. In each method, the method of flowing activated carbon is different. In the stirring type granulation method, the raw material powder is forcibly given a fluid motion by a stirring blade provided in the container. The fluidized bed granulation method is a method in which the powder is kept suspended and suspended in the fluid blown from below. The fluidized bed multifunctional granulation method is a stirring action, activated carbon inside the rotating vessel and if necessary. This is a method in which the rolling action for rolling other components is used in combination with the fluidized bed granulation method. The method of spraying the binder on the activated carbon that is flowing is not particularly limited, but is preferably a method of spraying a dispersion containing the binder. The composite particles of the present invention can be obtained by agglomerating and granulating in this way. The temperature of the fluidized bed containing activated carbon is usually 20 to 300 ° C, preferably 50 to 200 ° C.

  In these granulation methods, other components such as a conductive material and a dispersing agent may flow together with the activated carbon, or may be dispersed on the activated carbon together with the binder. In the case where the conductive material and other components are flowed together with the activated carbon, it is preferable that the conductive material and other components are attached in advance to the surface of the activated carbon because materials having different specific gravities can be uniformly dispersed. As a method for attaching the conductive material or the like to the surface of the activated carbon, for example, there is a mechanochemical treatment in which the activated carbon and the conductive material are mixed while applying a mechanical external force such as a compressive force or a shearing force. Equipment for mechanochemical treatment includes kneaders such as pressure kneaders and two rolls; high-speed impact dry powder compounding equipment such as rotating ball mills and hybridization systems (manufactured by Nara Machinery Co., Ltd.); mechanofusion A compression shear type dry powder compounding apparatus such as a system (manufactured by Hosokawa Micron Corporation) or the like can be used. In addition, when spraying the conductive material and other components together with the binder, for example, the binder, the conductive material, and the dispersant are uniformly mixed in a solvent, and the obtained mixed dispersion is put into a fluidized bed of activated carbon. Spraying and granulation can be performed.

  The composite particles obtained by the above production method include activated carbon, a conductive material, a binder, and water. Moreover, other components, such as a dispersing agent, may be included. The amount of the binder in the composite particles is 2 wt% or more and 20 wt. %, Preferably 3 wt. % Or more and 20 wt. %, More preferably 4 wt. % Or more and 20 wt. %, And the amount of water in the composite particles is 2 wt. % Or more and 40 wt. %, Preferably 3 wt. % Or more and 30 wt. %, More preferably 4 wt. % Or more and 25 wt. %.

  You may post-process after particle manufacture with respect to the composite particle obtained by said manufacturing method as needed. As a specific example, the composite particles are mixed with the above-mentioned activated carbon, conductive material, binder or dispersant, etc., thereby modifying the particle surface and improving or decreasing the fluidity of the spherical composite particles. The pressure moldability can be improved, the electrical conductivity of the spherical composite particles can be improved, and the like.

(Dry molding)
The production method in the case of producing the capacitor electrode composition layer for a lead storage battery by a dry molding method is not particularly limited, but it is preferable to supply composite particles on a support and press-mold with a pair of press rolls. . That is, it is preferable that the composite particles are supplied onto a support, formed into a sheet-like capacitor layer by a pair of press rolls, and pressed onto the surface of the support.

(Support)
The support used in the present invention is preferably used for supporting the capacitor layer and bonding the capacitor layer to the lead electrode. As a material constituting the support used in the present invention, an inorganic material or an organic material can be used without limitation as long as the capacitor layer can be formed on the support. For example, metal foil such as aluminum foil and copper foil; plastic film; paper and the like can be mentioned. Moreover, you may use the film of the multilayered structure which accumulated the said film. Among these, paper and thermoplastic resin film are preferable from the viewpoint of versatility and handling, and among paper and thermoplastic resin film, in particular, PET (polyethylene terephthalate) film, polyolefin film, PVA (polyvinyl alcohol) film, PVB (Polyvinyl butyral film) and PVC (polyvinyl chloride) film are preferable. In addition, the collector used for a lead electrode is not included as a support body in this invention. Moreover, it is preferable not to use a lead electrode as a support. That is, it is preferable not to press-mold the capacitor layer directly on the lead active material layer of the lead electrode.

Moreover, it is preferable that the surface which contacts the capacitor layer of the support body is roughened. Since the surface of the support that is in contact with the capacitor layer is roughened, it can be in close contact with the capacitor layer due to the anchoring effect and can be rolled up. Moreover, when manufacturing a lead-acid battery electrode using a capacitor layer with a support formed by forming a capacitor layer on the support, the support can be easily peeled from the capacitor layer. The surface roughness Ra of the roughened surface of the support is preferably in the range of 0.1 to 5 μm, more preferably 0.2 to 3 μm, and still more preferably 0.2 to 1 μm. When the surface roughness Ra of the roughened surface of the support is in this range, the adhesion between the capacitor layer and the support, and the support when the electrode is manufactured using the capacitor layer with the support, are provided. Coexistence with releasability becomes possible.
The surface roughness Ra can be calculated from the equation shown below by drawing a roughness curve using, for example, a nanoscale hybrid microscope (VN-8010, manufactured by Keyence Corporation) in accordance with JIS B0601. In the following formula, L is the measurement length, and x is the deviation from the average line to the measurement curve.

  The method for roughening the surface of the support is not particularly limited, a method for embossing the surface of the support; a method for sandblasting the surface of the support; a method for kneading the mat material into the material constituting the support; Examples thereof include a method of coating the surface of the support on the surface of the support. Among them, a method of sandblasting the support surface from the viewpoint of adhesion with the capacitor layer is preferable. The roughening treatment of the support may be performed only on one side or on both sides.

  In the case of releasing the surface of the support, the method of releasing is not particularly limited. For example, a thermosetting resin such as an alkyd resin is coated on the support and cured; the silicone resin is supported. It is preferable to use a method of coating on a body and curing it; a method of coating a fluororesin on a support. In particular, from the viewpoint of easily forming a uniform release treatment layer, a release treatment using a thermosetting resin is preferable, and the moldability of the capacitor layer and the case where the capacitor layer is transferred from the support to another support From the standpoint of balance with the ease of transfer, the release treatment by coating and curing the alkyd resin is preferred.

  Although the thickness of a support body is not specifically limited, 10-200 micrometers is preferable, 20-150 micrometers is more preferable, 20-100 micrometers is especially preferable. Moreover, although a width is not specifically limited, Preferably it is 100-1000 mm, More preferably, it is 100-500 mm.

Further, the tensile strength of the support is not particularly limited, but is preferably 30 to 500 MPa and more preferably 30 to 300 MPa from the viewpoint of preventing breakage during the production of the capacitor layer.
The support used in the present invention can be used repeatedly. By repeatedly using the support, the production cost of the electrode can be further suppressed.

  FIG. 1 is a diagram showing a specific aspect of a process of supplying composite particles onto a support and press-molding them with a pair of press rolls arranged substantially horizontally to obtain a sheet-like capacitor layer.

  In FIG. 1, the winding body of the support body 14 is attached to the unwinder 11, and this is sent out. Next, the composite particles 13 are supplied to a pair of press rolls 12 arranged substantially horizontally by a supply device such as a screw feeder, and are pressed by the pair of press rolls 12 to form the composite particles into a sheet shape. The capacitor layer, which is a body, is molded, and this is pressure-bonded to the surface of the support. And the support body (capacitor layer with a support body) in which the capacitor layer was formed is wound up with the winder 10, and the winding body of the capacitor layer with a support body is obtained.

  Of the press rolls constituting the pair of press rolls 12, at least one is preferably a rubber roll. By using a rubber roll, the strength of the obtained lead-acid battery electrode is improved. Moreover, when using a rubber roll, it is preferable that the hardness of the rubber roll is 10 ° or more and less than 95 °. Here, the hardness of the rubber roll is a value measured according to JIS K-6253.

  The pair of press rolls 12 shown in FIG. 1 may be replaced with a pair of press belts.

  The molding speed is preferably 0.1 to 100 m / min, more preferably 4 to 50 m / min. Moreover, the press linear pressure between rolls becomes like this. Preferably it is 0.2-30 kN / cm, More preferably, it is 1.5-15 kN / cm. Moreover, the forming speed when using a press belt instead of the press roll is preferably 1 to 15 m / min, more preferably 5 to 10 m / min. The pressure between the pressing belts is preferably 5 to 50 MPa, more preferably 10 to 30 MPa.

  Further, post-pressurization may be further performed as necessary in order to eliminate variations in the thickness of the capacitor layer formed by pressure molding and increase the density of the capacitor layer to increase the capacity. The post-pressing method is generally a roll press process. In the roll press process, two cylindrical rolls are arranged vertically in parallel at a narrow interval, each is rotated in the opposite direction, and an electrode is sandwiched between them to apply pressure. The roll used in the roll press step may be temperature-controlled by heating or cooling.

The density of the capacitor layer is not particularly limited, but is preferably 0.30 to 10 g / cm ³ , more preferably 0.35 to 5.0 g / cm ³ , and further preferably 0.40 to 3.0 g / cm ³ . ³ . The thickness of the capacitor layer is not particularly limited, but is preferably 5 to 1000 μm, more preferably 20 to 500 μm, and still more preferably 30 to 400 μm.

  Further, the peel strength between the support and the capacitor layer is preferably 0.1 to 100 N / m from the viewpoint of achieving both proper adhesion of the capacitor layer to the support and appropriate peelability from the support. Preferably it is 0.1-10 N / m, More preferably, it is 0.1-1 N / m. The peel strength is a value measured according to JIS Z0237.

(Electrode for lead acid battery)
The lead-acid battery electrode includes a lead electrode and a capacitor layer.

(Lead electrode)
The lead electrode used in the present invention refers to an electrode in which a lead active material layer is formed on a current collector. Lead active material layer contains lead and lead compounds such as lead, lead monoxide, lead dioxide, dilead trioxide, trilead tetroxide (lead red), lead sulfate, etc. Refers to the main layer. These lead and lead compounds can be used alone or in a suitable mixture. The proportion of the lead atoms in the lead active material layer is preferably 50 wt.% With respect to the weight of the entire layer from the viewpoint of increasing the energy density of the active material layer. % Or more, more preferably 70 wt. % Or more.

  The lead-containing material used for the positive electrode active material layer is preferably lead dioxide or lead monoxide, and the lead-containing material used for the negative electrode active material layer is preferably lead monoxide or lead.

  The lead active material layer may contain a reinforcing material such as polyester fiber, a surfactant such as lignin, barium sulfate and the like in addition to lead and a lead compound. Further, an additive selected from oxides, hydroxides or sulfates of antimony, zinc, cadmium, silver and bismuth can be used. Further, when a lead active material layer is formed by producing a paste of a lead-containing material, an aqueous sulfuric acid solution can be added.

  Examples of the current collector include a plate-shaped, foil-shaped, clad-type porous tube in which a lead alloy core is inserted, and a grid-shaped current collector. A grid-like current collector is preferable because it is optimal as a shape that holds the lead active material paste and efficiently extracts current. As the grid current collector, any of a standard grid, a radial grid, and an expanded type can be used.

As the material of the grid-like current collector, a lead-containing alloy such as a lead-calcium alloy, a lead-antimony alloy, or a lead-tin alloy is used. Arsenic, tin, copper, silver, aluminum, or the like may be included as part of the composition of the lead alloy.
The lead active material layer can be formed by preparing a paste by adding a solvent and an additive to a lead-containing material and filling the paste on a grid-like current collector.

  For example, when using a grid current collector, a lead active material layer is formed on a part of the grid plane of the grid current collector, a lead active material layer is formed on the entire grid surface of the grid current collector, and the like. It is done.

  In the present invention, the lead electrode may have an adhesive layer on the lead active material layer. By providing the adhesive layer, the adhesion between the capacitor layer and the lead active material layer can be improved, and the contact resistance can be reduced.

  The adhesive layer contains a filler as an essential component and includes optional components such as a binder and a dispersant. As the filler, known ones can be used, and specific examples include conductive fillers and metal oxide fillers. Among these, it is preferable to use a conductive filler.

(Method for producing lead-acid battery electrode)
The lead active material layer and the capacitor layer must be electrically connected. Therefore, these layers are preferably pressure bonded. For example, the capacitor layer is pressure-molded on the lead active material layer filled in the grid-shaped current collector by the above-described lead active material layer formation method. For example, pressure bonding between the lead active material layer and the capacitor layer is performed by placing and pressing the capacitor layer with support so that the capacitor layer side faces the lead active material layer.

  The method for producing the lead-acid battery electrode is not particularly limited, but the step of bonding the capacitor layer of the capacitor layer with support to the lead electrode (hereinafter sometimes referred to as “first production method”), or the capacitor with support. It is preferable to manufacture by a step of peeling the support of the layer from the capacitor layer and a step of bonding the capacitor layer to the lead electrode (hereinafter sometimes referred to as “second manufacturing method”).

(First manufacturing method)
In the 1st manufacturing method of this invention, the capacitor layer of the capacitor layer with a support body is bonded together to a lead electrode.

  The linear pressure when the capacitor layer of the capacitor layer with support is bonded to the lead electrode is such that when the roughened support is used, the shape of the roughened surface of the support is not impaired. Although not particularly limited, from the viewpoint that the capacitor layer can be uniformly bonded onto the lead electrode and the strength of the resulting lead storage battery electrode is excellent, it is preferably 50 to 2,000 kN / m, more preferably 100 to 1. 1,000 kN / m, more preferably 200 to 500 kN / m.

  In the first manufacturing method, heat may be applied simultaneously with the pressure bonding (hot pressing). Specific examples of the hot press method include a batch hot press and a continuous hot roll press, and a continuous hot roll press capable of improving productivity is preferable. The temperature of the hot press is not particularly limited, but is preferably 50 to 200 ° C., more preferably 70 to 150 ° C. from the viewpoint that the capacitor layer can be more uniformly bonded onto the lead electrode and the electrode strength is excellent. .

  In the first manufacturing method, the support-attached capacitor layer bonded to the lead electrode can be used as it is as a lead-acid battery electrode, but the support may be peeled off from the capacitor layer.

  In the first manufacturing method, the method of peeling the support from the capacitor layer with the support is not particularly limited. For example, after the capacitor layer with the support is bonded to the lead electrode, the capacitor including the capacitor layer and the lead electrode It can peel easily by winding a lead electrode with a layer, and a support body on a separate roll.

(Second manufacturing method)
The second production method of the present invention includes a step of peeling the support of the capacitor layer with the support from the capacitor layer, and a step of bonding the peeled capacitor layer to the lead electrode.

  The method for peeling the support of the capacitor layer with the support from the capacitor layer is not particularly limited, and the capacitor layer and the support are easily peeled from the capacitor layer with the support by winding them on separate rolls. be able to.

  When the capacitor layer peeled off from the capacitor electrode composition layer with a support is bonded to a lead electrode, the line pressure of the roughened surface of the support is impaired when a roughened support is used. As long as it is not limited, it is not particularly limited, but from the viewpoint that the capacitor layer can be uniformly bonded onto the lead electrode and the strength of the obtained lead storage battery electrode is excellent, preferably 50 to 2,000 kN / m, more Preferably it is 100-1,000 kN / m, More preferably, it is 200-500 kN / m.

  In the second manufacturing method, heat may be applied simultaneously with the pressure bonding (hot pressing). Specific examples of the hot press method include a batch hot press and a continuous hot roll press, and a continuous hot roll press capable of improving productivity is preferable. The temperature of the hot press is not particularly limited, but is preferably 50 to 200 ° C., more preferably from the viewpoint that the capacitor layer can be more uniformly bonded onto the lead electrode and the strength of the resulting lead storage battery electrode is excellent. 70-150 ° C.

(Lead battery)
The lead acid battery of the present invention includes a positive electrode and a negative electrode, a separator disposed between the positive electrode and the negative electrode, and an electrolyte, and at least one of the positive electrode and the negative electrode is an electrode for a lead acid battery having a capacitor layer.

A lead-acid battery usually has a plurality of pairs of structures in which at least one of the positive electrode and the negative electrode is an electrode for a lead-acid battery having a capacitor layer, with the positive electrode and the negative electrode facing each other with a separator interposed therebetween, or The negative electrodes are each electrically short-circuited. By setting it as such a structure, the capacity | capacitance of a lead storage battery can be enlarged.
In the lead storage battery of the present invention, examples of the constituent elements other than those described above include a battery case and a lid for storing the above constituent elements.

(Separator)
As the separator used in the lead storage battery of the present invention, it is possible to use one or a combination of separators such as papermaking, microporous polyethylene, microporous polypropylene, microporous rubber, retainer mat, glass mat, etc. it can.

(Electrolyte)
The electrolytic solution used in the lead storage battery of the present invention is usually sulfuric acid. Although the density of sulfuric acid varies depending on the charge / discharge state, the density is preferably 1.25 to 1.30 g / cm ³ (20 ° C.) in a fully charged state after chemical conversion treatment of the lead storage battery.

(Battery, lid)
In the lead-acid battery of the present invention, the positive electrode, the negative electrode, the separator, and the battery case and the lid for storing the electrolyte include ethylene-propylene copolymer, polyethylene, polypropylene, polyacrylonitrile-styrene copolymer, polyacrylonitrile-butadiene-styrene. What uses a copolymer as a raw material can be used.

(Battery)
As described above, a plurality of structures in which the positive electrode and the negative electrode are opposed to each other with the separator interposed therebetween, and the above-described lead storage battery capacitor electrode is disposed between at least one of the positive electrode and the separator and between the negative electrode and the separator. A plurality of lead storage batteries having a structure in which a pair of positive electrodes and negative electrodes are short-circuited can be prepared and connected in series. By doing in this way, the electromotive force of the whole lead acid battery can be enlarged. There is no need to prepare a plurality of battery cases in order to connect in series. A plurality of partitions are provided in one battery case, and the structure including the above-described positive electrode, negative electrode, separator, and lead-acid battery capacitor electrode is provided for each partition. If it is housed and connected in series, an integrated lead-acid battery with high electromotive force can be produced.

  According to the method for producing a capacitor electrode composition layer for a lead storage battery and the electrode for a lead storage battery of the present invention, a lead storage battery having a high strength and a lead storage battery having a low resistance can be obtained.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto. In the examples, parts and% are based on weight unless otherwise specified.
In Examples and Comparative Examples, the determination of the strength of the capacitor layer, the electrolyte impregnation property, and the internal resistance was performed as follows.

(Capacitor layer strength)
The capacitor layers obtained in Examples and Comparative Examples were measured according to JIS K6251. Specifically, the support was peeled from the capacitor layer with a support obtained in Examples and Comparative Examples, and dried at 160 ° C. for 40 minutes. Thereafter, it was punched into the shape of No. 1 dumbbell-shaped test piece, a tensile test was conducted at an atmospheric temperature of 25 ° C. and a tensile speed of 10 mm / min, and the maximum load at break was measured. This measurement was repeated 6 times, and the value obtained by dividing the average value of the maximum load by the cross-sectional area of the sheet was taken as the tensile strength of the capacitor layer, and evaluated according to the following criteria. The results are shown in Table 1.
It shows that the larger the tensile strength of the capacitor layer, the less likely to crack and break, and the better the shape retention.
A: 0.5 MPa or more B: 0.4 MPa or more and less than 0.5 MPa C: 0.3 MPa or more and less than 0.4 MPa D: Less than 0.3 MPa

(Electrolytic solution impregnation)
The lead-acid battery electrodes obtained in the examples and comparative examples were cut into 2 cm × 2 cm. One drop of 5 μL of the electrolytic solution was dropped on the electrode at an ambient temperature of 25 ° C., and the time (minutes) until the droplet of the electrolytic solution was absorbed from the electrode surface and could not be confirmed with the naked eye was measured. The measurement results were evaluated according to the following criteria. The shorter this time is, the better the electrode is. Here, 38% sulfuric acid aqueous solution was used as the electrolytic solution.
A: Less than 10 minutes B: 10 minutes or more and less than 20 minutes C: 20 minutes or more and less than 30 minutes D: 30 minutes or more

(Internal resistance)
The capacitor layers obtained in the examples and comparative examples were punched into a circular shape having a diameter of 12 mm. The capacitor layer and the glass fiber separator are sufficiently impregnated with an electrolytic solution, and then the two capacitor electrodes are opposed to each other with the separator interposed therebetween so that the capacitor electrodes are not in electrical contact with each other. A capacitor was produced. Sulfuric acid was used as the electrolyte.

The internal resistance was determined by conducting a charge / discharge test of the electric double layer capacitor. That is, the charging current is performed using a current value at which the current value per unit area of the electrode is 6.6 mA / cm ^2, and when the voltage reaches 1.0 V, the voltage is maintained for 10 minutes for constant voltage charging. Completed charging. Then, immediately after the end of charging, constant current discharging is performed until the voltage reaches 0 V at a current value similar to that used during charging. The capacitance was calculated from the amount of electric power at the time of discharge using an energy conversion method.

  Next, using this capacitance, charging is started at a constant current of 5 mA / F so that the charging / discharging speed of the electric double layer capacitor is constant, and the charging times of constant current charging and constant voltage charging are matched. Charging was completed at the time when the charging was performed for 20 minutes, and further, constant current discharging was performed immediately after the end of charging until the voltage reached 0 V at a current value similar to that used during charging.

The internal resistance is a value obtained by dividing the amount of voltage drop at the start of discharge from the extrapolation of the approximate curve by the least square method of the voltage data from the start of discharge to the predetermined time divided by the discharge current value, and the resistivity per volume, that is, the volume Expressed as resistivity and evaluated according to the following criteria. However, the predetermined time was 10% of the total discharge time. The results are shown in Table 1.
A: Less than 0.6Ω B: 0.6 or more and less than 0.8Ω C: 0.8 or more and less than 1.0Ω D: 1.0Ω or more

Example 1
(Production of binder)
Into a nitrogen-substituted polymerization reactor, 45 parts of acrylonitrile, 50 parts of 1,3-butadiene, 5 parts of methacrylic acid, 0.2 part of t-dodecyl mercaptan, 132 parts of soft water, 3.0 parts of sodium dodecylbenzenesulfonate, β- Naphthalenesulfonic acid formalin condensate sodium salt 0.5 part, potassium persulfate 0.3 part and ethylenediaminetetraacetic acid sodium salt 0.05 part are charged, and polymerization conversion reaches 90% while maintaining the polymerization temperature at 40 ° C. Reacted. Thereafter, 0.1 part of sodium dimethyldithiocarbamate was added as a polymerization terminator to terminate the polymerization reaction. After removing unreacted monomers from the obtained aqueous dispersion of copolymer particles, the pH of the aqueous dispersion of copolymer particles and the solid content concentration are adjusted to obtain a copolymer having a solid content concentration of 40% and a pH of 8 An aqueous particle dispersion was obtained. After the obtained copolymer particle aqueous dispersion was stored for one week, BIT (1,2-benz-2-methyl-4-isothiazolin-3-one) as a preservative was solidified in the copolymer particle aqueous dispersion. 0.2 part was added to 100 parts per minute and stirred to obtain a binder. The binder had a Tg of −20 ° C. and a volume average particle size of 100 nm.

(Production of composite particles)
100 parts of high-purity activated carbon powder derived from petroleum pitch having a specific surface area of 2,200 m ² / g and a weight average particle diameter of 5 μm as a capacitor electrode active material, and acetylene black (trade name “DENKA BLACK POWDER”: Electric 5 parts by chemical industry), 1.5 parts aqueous solution of carboxymethylcellulose (trade name “WS-C”: manufactured by Daicel Chemical Industries) as a dispersant, 1.4 parts by weight equivalent to the solid content, and binder Six parts were mixed in an amount corresponding to the solid content, and ion exchange water was further added so that the solid content concentration was 20%, and the mixture was dispersed to obtain a slurry.

  This slurry is spray-dried using a spray dryer (Okawara Chemical Co., Ltd.) at a rotational speed of 25,000 rpm of a rotating disk type atomizer (diameter 65 mm), a hot air temperature of 150 ° C., and a particle recovery outlet temperature of 90 ° C. Granulation was performed to obtain spherical composite particles. The average volume particle diameter of the composite particles was 80 μm, and the amount of water in the composite particles was 10% with respect to the weight of the activated carbon.

(Preparation of capacitor electrode composition layer for lead acid battery)
The obtained composite particles are supplied onto a paper-like support (short fibers = length 1 to 2 mm, width 20 μm, thickness 25 μm), and molded using a rubber roll (hardness 70 ° (JIS K-6253)). Pressure molding was performed under the conditions of a speed of 20 m / min and a press linear pressure of 5.0 kN / cm (500 kN / m). As a result, a capacitor layer with a support including a capacitor layer having a thickness of 200 μm and a density of 0.54 g / cm ³ was obtained.

( Reference Example 2)
Composite particles were prepared in the same manner as in Example 1 except that the amount of the binder in the slurry used when preparing the composite particles was 18 parts corresponding to the solid content. Further, using this composite particle, a capacitor electrode composition layer for a lead storage battery and a lead storage battery electrode were prepared in the same manner as in Example 1.

(Example 3)
Composite particles were prepared in the same manner as in Example 1 except that the amount of the binder in the slurry used when preparing the composite particles was changed to 3 parts corresponding to the solid content. Further, using this composite particle, a capacitor electrode composition layer for a lead storage battery and a lead storage battery electrode were prepared in the same manner as in Example 1.

Example 4
(Production of composite particles)
5 parts of acetylene black (trade name “Denka Black Powder”: manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive material, and 2% aqueous solution of carboxymethyl cellulose (trade name “WS-C”: manufactured by Daicel Chemical Industries, Ltd.) as a dispersant. 70 parts of the same binder as that used in Example 1 was mixed in an amount corresponding to the solid content, 60 parts of water was further added, and the mixture was mixed with a planetary mixer to obtain a mixed liquid (I).

Next, 100 parts of high-purity activated carbon powder derived from petroleum pitch having a specific surface area of 2,200 m ² / g and a weight average particle diameter of 5 μm as an electrode active material is supplied to a fluidized bed granulator (Agromaster; manufactured by Hosokawa Micron). The mixture (I) was spray-dried for 10 minutes in an air stream at 80 ° C. to obtain mixture particles having a particle diameter of 80 μm. The amount of water in the composite particles was 30% with respect to the weight of the activated carbon.

  Using the composite particles, a capacitor electrode composition layer for a lead storage battery and a lead storage battery electrode were prepared in the same manner as in Example 1.

( Reference Example 5)
The amount of the binder used when producing the composite particles was 10 parts, and the spray drying temperature was changed to 180 ° C., and composite particles were produced in the same manner as in Example 1. The amount of water in the obtained composite particles was 3% with respect to the weight of the activated carbon. Further, using this composite particle, a capacitor electrode composition layer for a lead storage battery and a lead storage battery electrode were prepared in the same manner as in Example 1.

(Example 6)
The composite particles were prepared in the same manner as in Example 1 except that the amount of the binder used when preparing the composite particles was 10 parts and the rotation speed of the atomizer was changed. The volume average particle diameter of the obtained composite particles was 140 μm. Further, using this composite particle, a capacitor electrode composition layer for a lead storage battery and a lead storage battery electrode were prepared in the same manner as in Example 1.

( Reference Example 7)
The composite particles were prepared in the same manner as in Example 1 except that the amount of the binder used when preparing the composite particles was 10 parts and the rotation speed of the atomizer was changed. The obtained composite particles had a volume average particle diameter of 55 μm. Further, using this composite particle, a capacitor electrode composition layer for a lead storage battery and a lead storage battery electrode were prepared in the same manner as in Example 1.

(Comparative Example 1)
The composite particles were prepared in the same manner as in Example 1 except that the amount of the binder in the slurry used for preparing the composite particles was 25 parts corresponding to the solid content. Further, using this composite particle, a capacitor electrode composition layer for a lead storage battery and a lead storage battery electrode were prepared in the same manner as in Example 1.

(Comparative Example 2)
Composite particles were prepared in the same manner as in Example 1 except that the amount of the binder in the slurry used for preparing the composite particles was 1 part corresponding to the solid content. In addition, although the capacitor electrode composition layer for lead acid batteries was produced similarly to Example 1, the capacitor layer could not be produced due to insufficient strength.

(Comparative Example 3)
Composite particles were prepared in the same manner as in Example 4 except that the amount of the binder used when preparing the composite particles was 25 parts and the drying temperature was changed to 60 ° C. The amount of water in the obtained composite particles was 50% with respect to the weight of the activated carbon. In addition, although the capacitor electrode composition layer for lead acid batteries was produced similarly to Example 1, the capacitor layer could not be produced due to insufficient fluidity.

(Comparative Example 4)
Composite particles were prepared in the same manner as in Example 1 except that the amount of the binder used when preparing the composite particles was 25 parts and the amount of ion-exchanged water was changed. The amount of water in the obtained composite particles was 1% with respect to the weight of the activated carbon. Further, using this composite particle, a capacitor electrode composition layer for a lead storage battery and a lead storage battery electrode were prepared in the same manner as in Example 1.

(Comparative Example 5)
The composite particles were prepared in the same manner as in Example 1 except that the amount of the binder used when preparing the composite particles was 25 parts and the rotation speed of the atomizer was changed. The obtained composite particles had a volume average particle size of 30 μm. Further, using this composite particle, a capacitor electrode composition layer for a lead storage battery and a lead storage battery electrode were prepared in the same manner as in Example 1.

(Comparative Example 6)
The composite particles were prepared in the same manner as in Example 1 except that the amount of the binder used when preparing the composite particles was 25 parts and the rotation speed of the atomizer was changed. The obtained composite particles had a volume average particle size of 250 μm. In addition, a capacitor electrode composition layer for a lead storage battery was produced in the same manner as in Example 1, but the accuracy was poor and the shape could not be maintained.

  As shown in Table 1, composite particles for a capacitor electrode composition layer for a lead storage battery containing activated carbon, a conductive material, a binder, and water, wherein the binder is 2 wt. % Or more and 20 wt. %, And the water is 2 wt. % Or more and 40 wt. The strength, the electrolyte solution impregnation property, and the internal resistance of the capacitor layer produced using the composite particles for a capacitor electrode composition layer for a lead storage battery having a volume average particle diameter of 50 μm or more and less than 200 μm were good.

DESCRIPTION OF SYMBOLS 10 ... Winder, 11 ... Unwinder, 12 ... Roll for press, 13 ... Composite particle, 14 ... Support

Claims (4)

A composite particle for a capacitor electrode composition layer for a lead storage battery containing activated carbon, a conductive material, a binder, and water,
The binder is made of acrylonitrile-butadiene copolymer,
The binder is 2 wt. % To 10 wt. Including less than
The water was added at 4 wt. % Or more and 40 wt. Including less than
Composite particles for a capacitor electrode composition layer for a lead storage battery having a volume average particle size of 60 μm or more and less than 200 μm.   A method for producing a capacitor electrode composition layer for a lead storage battery, comprising the step of supplying the composite particles for a capacitor electrode composition layer for a lead storage battery according to claim 1 onto a support and press-molding with a pair of press rolls.   The method for producing a capacitor electrode composition layer for a lead storage battery according to claim 2, wherein at least one of the press rolls constituting the pair of press rolls is a rubber roll.   The method for producing a capacitor electrode composition layer for a lead storage battery according to claim 3, wherein the hardness of the rubber constituting the rubber roll is 10 ° or more and less than 95 °.

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