ES2361482T3 - GELIFYING AGENT FOR ALKALINE BATTERY AND ALKALINE BATTERY. - Google Patents

Abstract

Gelatinizer for alkaline batteries, comprising particles of crosslinked polymer (A) comprising, as one or more major constituent monomer units, (meth) acrylic acid and / or an alkali metal salt thereof having an average particle size of 0.1 to 2,000 μm; and a metal oxide in the form of superfine particles (1) having an average particle size of 0.1 to 50 nm.

Description

Gelling agent for alkaline battery and battery alkaline

Technical field

The present invention relates to a gelatinizer for alkaline batteries, and an alkaline battery. Plus specifically, the present invention relates to a gelatinizer for alkaline battery cathodes consisting mainly of a alkaline electrolyte and zinc powder, and to an alkaline battery that uses The gelatinizer

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Prior art

To date, it has been used primarily in alkaline battery cathodes a mixture of an alkaline electrolyte high concentration (an aqueous solution of potassium hydroxide high concentration, in which it dissolves if necessary rust zinc or similar), and zinc dust and / or zinc alloy powder. In order to prevent precipitation or fluidization of the dust of zinc and / or the like in the alkaline electrolyte, are used gelatinizers obtained by crosslinking poly (acid (meth) acrylic) or salts thereof with an agent of reticulation. Gelatinizers are usually classified into two types, being one of the same poly (meth) acrylic acids) cross-linked in the form of fine particles obtained by precipitation-polymerization or some other operation of (meth) acrylic acid in an organic solvent, such as benzene, in the presence of a very small amount of a crosslinking agent such as divinylbenzene, and the other being crosslinked polymers of (meth) acrylic acid and / or a alkali metal salt thereof that have a particle size relatively large, a typical example of which is a resin water absorbent The former are mainly used to improve Electrolyte viscosity or improve the injection property of the batteries (supplying the fluidity of the electrolytes), and these The latter are mainly used to improve resistance to impact of the batteries. In many battery manufacturers, the two together (Japanese patent applications open for consultation by the public (JP-A) no. 6-349484 and 7-65818).

However, these gelatinizers have advantageous effects to prevent precipitation or fluidization of the zinc powder, improving the impact resistance of the batteries, preventing the leakage of liquid from the batteries and achieving others, but if the amount of the added gelatinizer becomes greater, the gelatinizer causes the internal resistance value to rise of the battery, so that it results in problems such as decreases the discharge characteristic or the life of the battery.

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Summary of the invention

The present inventors performed an active investigation in view of the situation mentioned above. As a result, it has been found that the Discharge feature, life and other of a battery, maintaining the impact resistance and other of the battery, adding an additive in the form of superfine particles to the gelatinizer mentioned above or by adding an additive in superfine particle shape together with the gelatinizer to a alkaline electrolyte The present invention has thus been achieved.

A first object of the present invention is provide a gelatinizer that can extend the duration of a alkaline battery while maintaining the impact resistance of the battery.

A second object of the present invention is provide a gelatinizer that makes it possible to contribute to a reduction in time to produce an alkaline battery.

A third object of the present invention is provide a gelatinizer that makes it possible to produce a battery that It does not contain any harmful material to the human body, such as Benzene, at all.

That is, the present invention relates to following gelatinizers [1] to [7], and to alkaline batteries [8] to [9]:

[1] Gelatinizer :

A gelatinizer comprising particles of crosslinked polymer (A) comprising, as one or more units of main constituent monomer, (meth) acrylic acid and / or an alkali metal salt thereof that has a particle size average of 0.1 to 2,000 µm; and a metal oxide in the form of superfine particles (1) that has an average particle size from 0.1 to 100 nm.

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[2] Gelatinizer :

The gelatinizer [1] in which the amount of (1) is from 0.1 to 50 parts by mass in relation to 100 Mass parts of (A).

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[3] Gelatinizer :

The gelatinizer [1] in which the size of Average particle of (1) is from 0.1 to 50 nm.

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[4] Gelatinizer :

The gelatinizer [1] in which (1) is one or more metal oxides selected from the group consisting of TiO2, Bi 2 O 3, CuO, In 2 O 3, SnO 2 and Nb_ {O} {5}.

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[5] Gelatinizer :

The gelatinizer [1] in which (A) are crosslinked polymer particles comprising, as one or more major constituent monomer units, acid (meth) acrylic and / or an alkali metal salt thereof using an allyl ether type crosslinking agent and / or a vinyl type crosslinking.

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[6] Gelatinizer :

The gelatinizer [1] in which (A) are formed by a particulate crosslinked polymer (a1) that has an average particle size of 100 to 2,000 µm and / or a crosslinked polymer in the form of fine particles (a2) having a average particle size from 0.1 to 100 µm.

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[7] Gelatinizer :

The gelatinizer [1] in which (A) are formed by a cross-linked polymer in the form of particles (a1 ') that has an average particle size of 100 to 1,000 µm and / or a crosslinked polymer in the form of fine particles (a2 ') having a average particle size from 0.1 to 50 µm.

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[8] Gelatinizer :

The gelatinizer [1] in which (A) are crosslinked polymer particles obtained using polymerization in aqueous solution

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[9] Alkaline battery :

An alkaline battery in which particles of crosslinked polymer (A) comprising, as one or more units of main constituent monomer, (meth) acrylic acid and / or an alkali metal salt thereof that have a size of average particle of 0.1 to 2,000 µm, are used as gelatinizer for an alkaline electrolyte for a cathode, characterized in that comprises a metal oxide in the form of superfine particles (1) which has an average particle size of 0.1 to 100 nm in a Amount of 0.001 to 5% by mass of the alkali electrolyte.

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[10] Alkaline battery :

The alkaline battery, which uses the gelatinizers [2] to [8].

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Detailed description of the invention Crosslinked polymer particles

In the present invention, polymer particles crosslinked (A), which constitute one of the components constituents of a gelatinizer for alkaline batteries, are polymer particles comprising, as one or more units of main constituent monomer, (meth) acrylic acid and / or an alkali metal salt thereof. It is necessary that this polymer be stable over a long period even with the strong alkalinity of an alkaline electrolyte. Polymer is preferably a crosslinked polymer with a crosslinking agent that does not cut itself or a crosslinking agent in which the crosslinking points are not cut.

In this document, acid (meth) acrylic means acrylic acid or methacrylic acid. A metal salt thereof is a salt obtained by neutralizing the acrylic acid or methacrylic acid with an alkali metal such as potassium, sodium and lithium.

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Regarding acid neutralization (meth) acrylic with an alkali metal in the present invention, the crosslinked polymer particles (A) can be non-particles neutralized or neutralized particles since the gelatinizer of the present invention is used in an aqueous alkaline solution which has a high concentration; however, a part of the all (meth) acrylic acid can be neutralized according to the need arises in order to improve workability, spray (A) easily or achieve others when they occur (A).

When the acid is neutralized (meth) acrylic, it is advisable to add a alkali metal hydroxide, such as potassium hydroxide, sodium hydroxide or lithium hydroxide, or an aqueous solution of the same, to a monomer before polymerization or to a polymer after the polymerization and then the components are mixed. The agent of crosslinking that does not cut itself or the agent crosslinking in which the crosslinking points are not cut at over a long period even with the strong alkalinity of a alkaline electrolyte, has poor water solubility in many cases. Therefore, when (meth) acrylic acid is polymerized in a state in which its degree of neutralization is high, the crosslinking agent dissolves insufficiently in a aqueous solution of the monomer and separates even if added to the same a given amount of the crosslinking agent. In consecuense, a given uniform crosslinking cannot be carried out so that the crosslinked polymer (A) having the desired physical properties Therefore, it is preferable to set the degree of neutralization of (meth) acrylic acid a from 0 to 30 mol%, polymerize the (meth) acrylic acid and subsequently adjust the degree of neutralization if necessary adding an alkali metal hydroxide to the polymer.

When polymer particles are produced crosslinked (A) in the present invention, polymerizes (n) (meth) acrylic acid and / or an alkali metal salt thereof as one or more monomers, as one or more monomer units main constituents. If necessary, it can be copolymerized with it a different monoethylenic unsaturated monomer that It can be copolymerized with (meth) acrylic acid (alkaline). He unsaturated monoethylenic monomer can be any copolymerizable monomer, and is not particularly limited. The examples thereof include ethylenic unsaturated monomers anionics such as monomers containing acid groups carboxylic (salt) such as maleic acid (metal salts alkaline), fumaric acid (alkali metal salts) and acid itaconic (alkaline), monomers containing sulfonic acid groups (salt) such as acid acrylamide-2-methylpropanesulfonic acid (alkaline), (meth) sulfoalkyl and acid acrylate styrenesulfonic (alkaline); unsaturated ethylenic monomers non-ionic water soluble such as (meth) acrylamide, (meth) acrylamide substituted with N-alkyl (which it has 1 to 3 carbon atoms) [such as N-Methylacrylamide and N, N-dimethylacrylamide], N-Vinylacetoamide, mono (meth) acrylate of monohydroxyalkyl (having 1 to 3 carbon atoms), polyethylene glycol mono (meth) acrylate (degree of polymerization: from 2 to 100), mono (meth) acrylate polypropylene glycol (degree of polymerization: from 2 to 100) and methoxypolyethylene glycol mono (meth) acrylate (degree of polymerization: from 2 to 100); and other unsaturated monomers monoethylenic such as (meth) alkyl acrylate (having 1 to 5 carbon atoms) and vinyl acetate. These monomers ethylenic unsaturates can be used alone or in combination of two or more of them in an amount within a given range.

The amount of the ethylenic unsaturated monomer additive other than (meth) acrylic acid and / or metal salt alkaline thereof is preferably from 0 to 50% in mass, more preferably from 0 to 30% by mass of acid (met) acrylic used at the time of polymerization of the same. Hereinafter, "%" represents % by mass unless otherwise specified.

In the present invention, the agent of crosslinking that does not cut by itself or the agent of crosslinking in which the crosslinking points are not cut at over a long period even with the strong alkalinity of a alkaline electrolyte is preferably a crosslinking agent copolymerizable which has no group in the molecule of the same functional that easily hydrolyzes with strong alkalinity, such as an ester bond or an amide bond and that does not generate any groups functional that easily hydrolyzes with strong alkalinity even by crosslinking reaction.

Examples of a crosslinking agent Copolymerizable of this type include crosslinking agents of allyl ether type such as crosslinking agents (b1) having the molecule of the same two allyl groups and no hydroxyl groups, Typical examples of which are alkylene (which has 2 to 5 carbon atoms) glycol diallyl ether and diallyl ether of polyethylene glycol (PM: 100 to 4,000); crosslinking agents (b2) which have two allyl groups in the molecule of the same and from 1 to 5 hydroxyl groups, typical examples of which are diallyl ether of glycerin, diallyl trimethylolpropane ether, diallyl ether of pentaerythritol and diallyl polyglycerin ether; agents of cross-linking (b3) that have in the molecule thereof from 3 to 10 allyl groups and no hydroxyl groups, typical examples of which are trialyl ether of trimethylolpropane, triallyl ether of glycerin, tetraalyl ether of pentaerythritol and tetraalyloxyethane; Y crosslinking agents (b4) that have in the molecule thereof 3 to 10 allyl groups and 1 to 5 hydroxyl groups, typical examples of which are triallyl pentaerythritol ether, triallyl ether of diglycerin and polyglycerine polyallyl ether (degree of polymerization: from 3 to 13); and type crosslinking agents vinyl (b5) such as divinylbenzene and acid divinylbenzenesulfonic. These crosslinking agents can be used alone or in combination of two or more thereof.

Among these crosslinking agents, they are preferable (b4). Since the (b4) have in the molecule of the same from 1 to 5 hydroxyl groups and from 3 to 10 allyl groups, the (b4) have good compatibility with acrylic acid and / or salts of alkali metals. Additionally, the (b4) can compensate for the low peculiar copolymerization capacity of the allyl groups that the number of allyl groups in (b4) is large. In consequently, effective crosslinking can be achieved. Therefore, they are preferable (b4).

In the present invention, the amount added of the crosslinking agent (b), which depends on the type of the crosslinking used and the average degree of polymerization of the acid (meth) acrylic, is preferably from 0.01 to 2.0% by mass, more preferably from 0.03 to 1.0% in mass of (meth) acrylic acid (alkaline). If the amount added is 0.01% or more by mass, formation may be decreased strands of the gelatinizer produced in aqueous alkaline solution and also the stability of the gelatinizer can be improved in aqueous alkaline solution so that a viscosity decrease over time. If the amount added is 2.0% or less by mass, the crosslinking density of the crosslinked polymer does not become very high so that it is not reduced the absorption thereof in aqueous alkaline solution. In Consequently, the viscosity of the alkaline solution is not reduced aqueous to which the gelatinizer is added. Therefore you can prevent the separation of the alkaline electrolyte.

As described above, in the present invention, the crosslinking agent (b) that is not cut by itself or the crosslinking agent (b) in which the points of crosslinking is not cut over a long period even with the strong alkalinity of alkaline electrolyte is preferable as crosslinking agent. When a crosslinking agent is used copolymerizable ester type used in water absorbent resins common, such as trimethylolpropane triacrylate, copolymerizable cross-linking of the amide type, a typical example of which is methylene bisacrylamide, or crosslinking agents of type reactive with carboxylic acid, a typical example of which It is diglycidyl ether of ethylene glycol, the crosslinked structure resulting easily decomposes with strong alkalinity. By consequently, there is hardly any effect on the decrease in strand formation with strong alkalinity or improvement in stability of the gel concentration over a period long. However, some effect on the improvement may occur. in the dispersibility of the alkaline electrolyte gelatinizer, the improvement in its absorption rate in alkaline electrolyte, or Similar. Therefore, a small amount of an agent can be used of different crosslinking (c) together with (b).

Examples of the crosslinking agent (c) include copolymerizable crosslinking agents (c1) which have in the molecule thereof from 2 to 10 functional groups, examples typical of which are N, N'-methylenebisacrylamide, di (meth) ethylene glycol acrylate, di (meth) trimethylolpropane acrylate, tri (meth) trimethylolpropane acrylate, di (meth) pentaerythritol acrylate, tri (meth) pentaerythritol acrylate and pentaerythritol tetra (meth) acrylate; and agent of crosslinking reagents with carboxylic acid (c2), typical examples of which include polyhydroxy glycidyl compounds, a typical example of which is diglycidyl ether of ethylene glycol, polyhydroxylated isocyanate compounds, a typical example of which is 4,4'-diphenylmethane diisocyanate, polyhydroxylated amine compounds, a typical example of which is ethylenediamine, and polyhydric alcohol compounds, A typical example of which is glycerin.

In the event that the agent is used reagent crosslinking (c2) mentioned above, it is common that in any stage after the addition of the crosslinking agent, the reaction system is preferably heated to 100 to 230 ° C, more preferably at 120 to 160 ° C to advance the reaction of crosslinking. The reactive crosslinking agents (c2) can be alone within the range of quantities given, or they can used in combination of two or more thereof. In addition, the agent (s) (c2) can be used together with the agent copolymerizable crosslinking (c1) mentioned above.

The added amount of these agents of different crosslinking (c), which are added if necessary, is preferably from 0 to 0.5%, more preferably from 0 to 0.3% by mass of (meth) acrylic acid (alkaline).

Examples of the polymerization method for obtain the crosslinked polymer in the present invention include polymerization in aqueous solution, suspension polymerization of reverse phase, solution polymerization (organic), mass polymerization, the so-called polymerization by precipitation, in which a difference between solubility is used of a monomer and that of the resulting polymer in a solvent organic such as benzene to carry out the polymerization, and emulsion polymerization, in which an emulsifier is used suitable for polymerizing an aqueous acid solution (meth) acrylic (alkali metal salt) in a solvent organic.

Among these polymerization methods, they are preferable polymerization in aqueous solution, polymerization in reverse phase suspension and precipitation polymerization since the molecular weight of the crosslinked polymer rises easily to improve the effect of increasing the viscosity of the Gelatinizer easily. The polymerization in aqueous solution is more preferable when considering the following: the point of view that no organic solvent is used that can produce a harmful effect on the human body or the environment, such as benzene.

After that, the crosslinked polymer obtained by the polymerization mentioned above it is subjected to distillation removal / removal of water or solvents organic or dried if necessary. In addition, the resulting product it is sprayed and the particle size thereof is adjusted to a given particle size if necessary. In this way, they occur the crosslinked polymer particles (A).

The particle size of the crosslinked polymer particles (A) of the present invention is usually adjusted such that the average particle size of the dried product thereof will be from 0.1 to
2,000 µm, preferably from 0.1 to 1,000 µm. If the particle size is less than 0.1 µm, the production of the particles or their isolation from the solvent or the like is difficult in many cases. On the other hand, if the particle size is greater than 2,000 µm, in the cathode container or the filling pipe of an alkaline battery the particles cannot be introduced into the container or the pipe can become clogged since the particles are too large . The average particle size in the present invention means mass average particle size. The average mass particle size is measured by the graphical representation method of each particle size distribution of the crosslinked polymer on a logarithmic probability sheet in which its transverse axis represents the particle size thereof and its vertical axis represents the its content based on the mass, and then obtaining the particle size at the point where 50% of the total mass is occupied. It is preferable with respect to the particle size of (A) that the percentage content of the particles having a size less than 0.1 µm be 3% or less and that the percentage content of the particles having a size greater than 2,000 µm be 3% or less.

In the case where, in particular, they are used particles that have an average particle size of 100 to 2,000 um (a1) or, in particular, particles having a size of average particle of 100 to 1,000 µm (a1 '), between the particles that have particle sizes within the mentioned range previously, as a gelatinizer for alkaline batteries, they produce a particularly good effect on the improvement in resistance to impact of the batteries. On the other hand, in particular, particles that they have an average particle size of 0.1 to 100 µm (a2), plus preferably particles having a particle size average of 0.1 to 50 µm (a2 '), have a high viscosity but they can provide electrolyte fluidity; therefore they have a excellent effect to improve the injection property thereof in batteries using a pump or similar.

When polymer particles are produced crosslinked (A) that have a given particle size, the Spraying, which is done if necessary, can be based on a usual spray method (for example, a shredder impact, a barbed mill, a knife mill, a Skirel mill or a ball mill) in the case of (a1). In the case of (a2), it is preferable to use a high speed impact crusher rotation such as an ACM sprayer, air spray (a jet crusher or similar), freeze spray or Similary.

Usually, according to polymerization by precipitation or emulsion polymerization, the particles in a polymerization stage are already fine particles (from 0.1 to 100 \ mum). Therefore, if the solvent or the like is removed by distillation by a method such as spray drying or vacuum evaporation, spraying or the like may not have Recently performed in many cases.

Crosslinked polymers in the form of particles (a1) and (a2) can be used alone or in combination. With the purpose of aiming at the two effects mentioned above, is say, in order to improve the impact resistance of a pile and produce a high injection speed of an electrolyte that has an increased viscosity in a stack container easily, using a pump or similar, it is preferable to use (a1) and (a2) together, or use (a1) and (a2) mixed in advance. The mixing ratio between (a1) and (a2) can be arbitrary.

The added amount of the particles of crosslinked polymer (A) is preferably from 0.1 to 10% by mass, more preferably from 1 to 5% by mass of a 35-40% solution of potassium hydroxide in water, which is an alkaline electrolyte, as a total amount of (a1) and (a2). If the amount added is 0.1% or more by mass, the effect of increased viscosity of crosslinked polymer particles (A) is insufficiently revealed. If the quantity is 10% or less by mass, the electrolyte viscosity increase does not It is very high. Therefore, the electrolyte is easy to handle.

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Metallic oxide in the form of superfine particles

The metallic oxide in the form of particles superfine (1) used in the present invention is any oxide metallic in the form of superfine particles having a size of average particle of 0.1 to 100 nm and can be added to a gelatinizer or alkaline electrolyte, whereby the property Increasing the viscosity of the gelatinizer can be made high. Is preferably a metal oxide such as TiO2, Bi2O3, CuO, In_ {2} O 3 {, SnO_ {2} or Nb_ {2} {5} when you have in Note the following: the view that even in conditions commonly used for alkaline batteries, that is, even with the strong alkalinity of an alkaline electrolyte that has a temperature from -10 to 80 ° C, the oxide (1) does not dissolve along a long period and no hydrogen gas is generated in the container of cathode thereof or an elevation in the value of internal resistance TiO 2 is practical and particularly preferable due to the fact that it is also taken into account that TiO_ {2} is readily available, its costs, and others. These metal oxides can be used alone or in combination of two or More of them.

In impurity content in metal oxide in the form of superfine particles (1) used in the present invention It is preferably as small as possible for the use of same. In particular, the content of metals that can generate gas hydrogen or some other gas when metals are incorporated into a alkaline battery cathode material, such as iron, nickel, chrome, Molybdenum, lead, antimony and vanadium, is preferably 1% or less by mass, more preferably 0.1% or less by mass.

The particle size of the metal oxide in Superfine particle form (1) is usually from 0.1 up to 100 nm, preferably from 0.1 to 50 nm. If the size of particle is greater than 100 nm, the effect of increasing the Viscosity may be insufficient. On the other hand, if the size of particle is less than 0.1 nm, the particles are not even produced easily or easily obtained in many cases. With respect to the shape of the metal oxide in the form of superfine particles (1), no special limitations are imposed on them. The examples of the shape include spherical, granular, block and in scales The average particle size can be measured by a usual method, for example, calculation of values obtained by the BET method, the Sears method or the laser method.

When (1) is added to polymer particles crosslinked (A), the added amount thereof is preferably of from 0.1 to 50 parts by mass, more preferably from 0.5 up to 30 parts by mass in relation to 100 parts by mass of (A). If the amount added is 0.1 parts or more by mass and 50 parts or less in mass, the effect of increasing the viscosity of the Jelly is enough.

The method of addition in the case of adding (1) to (A) can be performed at any stage when the crosslinked polymer particles (A) if the particle size of (1) can be maintained. However, if (1) it enters into (A), (1) is covered with (A) so that the particle size does not It can be maintained. Therefore, it is preferable to add (1) after or when the crosslinked polymer is pulverized to give a powder and, if it is necessary, the combination is performed.

No special limitation is imposed on the addition device in the case of adding (1) to (A) if the device makes it possible to add a given amount of it. When a powder mixer such as a conical mixer, a V-shaped mixer, a belt mixer or a kneader, They can mix easily.

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Alkaline battery

Another of the present invention is a battery alkaline in which (A) and (1) are combined with a material of cathode.

Usually the cathode material of a stack Alkaline is composed of 30 to 200 parts of zinc powder or zinc alloy powder that has an average particle size from about 10 to 400 µm and from about 0.1 to 10 parts of a gelatinizer {crosslinked polymer particles (A)} in relation to 100 parts of an alkaline electrolyte (a 35-40% aqueous solution of potassium hydroxide in which zinc oxide dissolves). However, the alkaline battery of the present invention is a stack in which a given amount of metal oxide in the form of fine particles (1) is added in addition to it. The added amount of (1), which depends of the added amount of (A) used, is from 0.001 to 5% by mass, preferably from 0.01 to 3% by mass of the alkaline electrolyte If the amount added is less than 0.001% by mass, the effect of increasing viscosity is insufficient. By On the other hand, if the amount added is greater than 5% by mass, you can there is a bad effect on the discharge characteristic of the alkaline battery

The method to add (1) in the case of adding (1) when the cathode material of the alkaline battery is produced it can be any method that makes it possible for the material of Alkaline battery cathode can be mixed homogeneously with (one). Examples thereof include a method of adding (1) to the same time when a solution is mixed at about 35-40% potassium hydroxide in water, which is a alkaline electrolyte, with zinc dust, zinc oxide and crosslinked polymer particles (A) so that a alkaline battery cathode material, and then mix the added components; a method of adding the gelatinizer of the present invention, that is, (A) to which (1) is added; a method to combine (1) beforehand with used zinc powder, and subsequently add another cathode material to it; a method of add (A) and (1) to an aqueous solution of potassium hydroxide in which dissolves zinc oxide, and add zinc powder to the same.

After mixing according to the mentioned method previously, the amount of (1) can be mixed for an adjustment additional.

The alkaline battery thus produced can be used preferably as a primary battery for toys, players Portable CDs, portable MD players, electrical appliances for which a good impact resistance is required or discharge characteristic, and household electrical appliances laptops

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Best way to carry out the invention

Next in this document, the The present invention is further described by way of following examples and comparative examples. However, the The present invention is not limited thereto. As polymers crosslinks used in the examples and comparative examples, are produced crosslinked polymers 1 to 3 or were obtained by The following methods.

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Synthesis of a crosslinked polymer 1

In a beaker of 2 1, they put 200 g of acrylic acid, 0.4 g (0.2% by mass of acrylic acid) of Trialyl ether of pentaerythritol (manufactured by Daiso Co., Ltd.) and 800 g of water subjected to ion exchange, and then the resulting solution up to 8 ° C.

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This aqueous acrylic acid solution was put in a polymerization tank with thermal insulation of 1.5 1, and nitrogen was flowed into the aqueous solution so that it was fixed the amount of oxygen dissolved in the aqueous solution at 0.1 ppm or less. 4.0 g of peroxide water were added thereto 0.1% hydrogen, 4.0 g of a 0.1% acid solution L-ascorbic in water, and 1.0 g of a solution at 10% hydrochloride 2,2'-azobis (2-amidinopropane) (trade name: V-50, manufactured by Wako Pure Chemicals, Industries) in water. Nitrogen purge continued in the aqueous solution until the beginning of the polymerization. Since polymerization began so that the viscosity of the Aqueous acrylic acid solution began to rise, the purge with nitrogen and polymerization was continued for 6 hours. The temperature of the aqueous acrylic acid solution was measured With a point thermometer. As a result, the maximum temperature at the one that arrived was 63 ° C.

A crosslinked hydrated gel was taken in the form of polymerization tank block with thermal insulation, and it used a small meat grinder (manufactured by Loyal Co.) to subdivide the gel into a size of 3 to 10 µm. After of that, 139 g of a 40% solution was added thereto (grade neutralization: 50 mol%) of sodium hydroxide (reagent extrapure) in water, so that the gel is neutralized hydrous.

The neutralized hydrated gel was laminated in a thickness of 5 cm on a sieve composed of SUS and that had a sieve opening 850 µm in size. A dryer was used small air infiltration (manufactured by Inoue Kinzoku Co.) to infiltrate 120ºC hot air in the gel hydrated for one hour to dry the hydrated gel.

A kitchen mixer was used to pulverize the dried product, and a sieve was used to collect particles that they had particle sizes from 210 to 850 µm (particle size average: 400 µm). In this way, a polymer was obtained crosslinked 1.

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Synthesis of a crosslinked polymer 2

A jet mill crusher was used (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to submit the crosslinked polymer 1, which was obtained as described previously, to spray and classification. In this way, it obtained a crosslinked polymer 2 that had a particle size 15 µm average.

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Synthesis of a crosslinked polymer 3

Commercially available JUNLON PW-150 (fine particles of crosslinked poly (acrylic acid), a product obtained by precipitation of the benzene polymer, average particle size of 1 µm, crosslinking agent: divinylbenzene, manufactured by Nihon Junyaku Co was used ., Ltd.) per se as crosslinked polymer 3.

A liquid chromatography was used that had a UV detector (extraction solvent: hexane, wavelength of measurement: 320 nm) to measure the amount of benzene remaining in this crosslinked polymer 3. As a result, the remaining amount of Benzene was 15,100 ppm.

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Examples 1 to 3

In a vinyl polymer bag, they put 100 g of each of the 1 to 3 crosslinked polymers and 5 g of oxide of extremely pure titanium that had an average particle size 21 nm (trade name: P-25, manufactured by Nippon Aerosil Co., Ltd.). They then underwent vibration by hand plastic vinyl bags for about 3 minutes, so that the gelatinizers (1) to (3) of the present invention

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Examples 4 to 6

In a vinyl polymer bag, they put 100 g of each of the 1 to 3 crosslinked polymers and 10 g of oxide of indium that had an average particle size of 27 nm (name Commercial: Nanotec In_ {2} {3}, manufactured by C.I. Kasei Co., Ltd.). Then the bags of vibration were subjected to hand vinyl plastic for about 2 minutes, so that it produced the gelatinizers (4) to (6) of the present invention.

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Example 7

In a vinyl polymer bag, they put 50 g of the crosslinked polymer 1, 50 g of the crosslinked polymer 2 and 5 g of titanium oxide used in example 1 (P-25). Then the plastic bag was subjected to vibration by hand vinyl for about 3 minutes, so there was a gelatinizer (7) of the present invention.

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Comparative Examples 1 to 3

Crosslinked polymers 1 to 3 were used, such as they were, as comparative gelatinizers (a) to (c).

The gelatinizers (1) to (7) of the present invention and comparative gelatinizers (a) to (c) for measure their viscosity in a 40% solution of potassium hydroxide in water and the added amount thereof to adjust the viscosity of a cathode composition by means of following methods. The results are shown in Table 1.

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(I) Viscosity in a 40% mass solution of potassium hydroxide in water

In a 250 transparent polymer container 200 g of a 40% solution by mass were put with a lid of potassium hydroxide in water, in which 3% of zinc oxide. To this solution was added each of a 1.5% mass gelatinizer, a 2.0% mass gelatinizer and a 2.5% mass gelatinizer. The container of polymer, and then the entire vessel was stirred vigorously for about a minute. This vessel, in which it put the aqueous potassium hydroxide solution, let stand in a thermostat with a temperature of 25ºC for one hour. After that, a type B digital viscometer was used (manufactured by TOKIMEC Co.) to measure the viscosity of the content therein. Before the measurement, a Teflon rod was used to stir the contents evenly. The resulting value was defined as viscosity After an hour. (Measuring temperature: 40 ° C, rotor number 4, number of rotations: 3 rpm).

The sample whose viscosity measurement is He ended up stagnant again. The sample was put back on the thermostat temperature 25 ° C and allowed to stand in the state in which the sealed sample was kept for 24 hours. After that, the digital type B viscometer was used to measure the content viscosity under the same conditions. The value resulting was defined as viscosity after one day.

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(II) Amount of necessary addition of the gelatinizer

500 g of a 40% solution was added in mass of potassium hydroxide in water, in which 3% was dissolved in mass of zinc oxide, and 300 g of zinc powder. The gelatinizer to it until the viscosity after one day arrived up to 200 Pa · dots (25 ° C, 3 rpm, rotor number 4). The amount added thereof was defined as the amount of addition needed of the gelatinizer.

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Example 8

Crosslinked polymer 2 was used as gelatinizer, and viscosity and amount of addition were measured necessary according to the methods (I) and (II) mentioned above except that when the viscosity and the amount of necessary addition were measured by methods (I) and (II), were separately added 0.1% by mass of titanium oxide (P-25) to 40% mass solution of hydroxide of potassium in water. The results are shown in Table 1.

The necessary amounts of addition of gelatinizers (1) to (7) of the present invention, the comparative gelatinizers (a) to (c) and the obtained gelatinizer by the method of example 8, they were used to make batteries Model using the following method. Resistance values Internal battery life, battery life and resistance The impact of the batteries was measured by the following methods. Results are shown in table 2.

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Manufacture of each model stack

To a kneader that had an internal volume of 1 1 (internal package: Teflon treatment) 500 g was added of a 40% mass solution of potassium hydroxide in water, in which dissolved 3% by mass of zinc oxide, and the amount of necessary addition of each of the gelatinizers, obtaining the amount as described above (in example 8, separately added 0.1% by mass of titanium oxide to the 40% mass solution of potassium hydroxide in water). Be then mixed the components sufficiently for 60 minutes After that, the resulting solution was allowed to stand for 24 hours to prepare a zinc electrolyte gelatinized

Zinc electrolyte was degassed gelatinized under reduced pressure. Subsequently, this was used zinc electrolyte, and 15 g of it was injected into a container of cathode of a model battery type LR-20 illustrated in figure 1. In this way, a model battery was manufactured.

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(III) Internal resistance value of the battery

A measuring instrument of the resistance to measure the internal resistance value (\ Omega cm) of the model battery manufactured at room temperature (from 20 to 25 ° C).

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(IV) Battery life

An external resistor was connected that had a resistance value of 2 \ Omega at room temperature (from 20 to 25 ° C) to the manufactured model battery, and then the battery was discharged continuous way. The time was defined until the voltage was reduced up to 0.9 V as the battery life (h).

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(V) Resistance to battery impact

An external resistor was connected that had a resistance value of 2 \ Omega at room temperature (from 20 to 25 ° C) to a model cell manufactured in the same way as described previously. While the battery was discharged so continued, the model battery was dropped repeatedly 10 times from a height of 1 m. The voltage was measured before the fall and the voltage just after the fall, and then the resistance to the impact (%) from the following equation:

Resistance to impact (%) = voltage (V) just after (tenth) drop / voltage (V) before the fall X 100

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TABLE 1

one

2

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TABLE 2

3

4

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Industrial applicability

The gelatinizer or alkaline battery of the The present invention produces advantageous effects as described in continuation.

(i)

The addition of a given amount of a metal oxide in the form of superfine particles in the production of a gelatinizer or an alkaline battery makes it possible to increase the effect of Increased viscosity of the gelatinizer greatly. By consequently, the amount of necessary addition of the gelatinizer, which is a cause of increasing the internal resistance value of the alkaline battery so that the battery life decreases, you can reduce dramatically. Therefore, the battery life can increase while maintaining the impact resistance of the battery.

(ii)

The addition of particulate metal oxide fine to a gelatinizer causes an improvement in dispersibility of the gelatinizer in an alkaline electrolyte. Therefore, the Electrolyte viscosity can be increased in a short time. The improvement contributes to a reduction in the time to produce a battery.

(iii)

In the case where a polymerized product is used in aqueous solution as a gelatinizer, the difference in the effect of increased viscosity, which is a product problem polymerized in conventional aqueous solution, can be overcome compared to a product polymerized by precipitation in benzene. Therefore, a battery that does not contain can be manufactured no material harmful to the human body, such as benzene.

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Since the advantageous effects occur mentioned above, the gelatinizer of the present invention It is useful as a gelatinizer for primary alkaline batteries and secondary, such as alkaline button batteries, oxide batteries silver, nickel-cadmium storage batteries and nickel-hydrogen storage batteries as well as cylindrical alkaline batteries.

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Brief description of the drawing

Figure 1 is a sectional view illustrating an example of the alkaline battery of the present invention.

The explanation of the reference numbers is as follows.

one.

anode terminal plate

2.

shrink tube

3.

anode agent (MnO2 + C)

Four.

outer container

5.

separator

6.

dust collection rod

7.

meeting

8.

cathode terminal plate

9.

gel cathode

Claims (16)

1. Gelatinizer for alkaline batteries, which comprises crosslinked polymer particles (A) comprising, as one or more major constituent monomer units, acid (meth) acrylic and / or an alkali metal salt thereof that they have an average particle size of 0.1 to 2,000 µm; and a metallic oxide in the form of superfine particles (1) having a average particle size from 0.1 to 50 nm. 2. Gelatinizer for alkaline batteries according to claim 1, wherein the amount of (1) is from 0.1 to 50 parts by mass in relation to 100 parts by mass of (A). 3. Gelatinizer for alkaline batteries according to claim 1, wherein the average particle size of (1) It is from 0.1 to 50 nm. 4. Gelatinizer for alkaline batteries according to claim 1, wherein (1) is one or more metal oxides selected from the group consisting of TiO2, Bi2O3, CuO, In_ {2} {3}, SnO_ {2} and Nb_ {2} {5}. 5. Gelatinizer for alkaline batteries according to claim 1, wherein (A) are polymer particles crosslinked comprising, as one or more monomer units main constituents, (meth) acrylic acid and / or a salt alkali metal thereof using a type crosslinking agent allyl ether and / or a vinyl type crosslinking agent. 6. Gelatinizer for alkaline batteries according to claim 1, wherein (A) are formed by a polymer crosslinked in the form of particles (a1) having a size of average particle of 100 to 2,000 µm and / or a crosslinked polymer in the form of fine particles (a2) that has a particle size average of 0.1 to 100 µm. 7. Gelatinizer for alkaline batteries according to claim 1, wherein (A) are formed by a polymer crosslinked in the form of particles (a1 ') having a size of average particle of 100 to 1,000 µm and / or a crosslinked polymer in the form of fine particles (a2 ') that has a particle size average of 0.1 to 50 µm. 8. Gelatinizer for alkaline batteries according to claim 1, wherein (A) are polymer particles cross-linked obtained using polymerization in aqueous solution. 9. Alkaline battery in which crosslinked polymer particles (A) comprising, as one or more major constituent monomer units, (meth) acrylic acid and / or an alkali metal salt thereof having an average particle size of 0.1 to 2,000 µm, are used as gelatinizer for an alkaline electrolyte for a cathode, characterized in that it comprises a metal oxide in the form of superfine particles (1) having an average particle size of 0.1 to 100 nm in a Amount of 0.001 to 5% by mass of the alkaline electrolyte. 10. Alkaline battery according to claim 9, in which the amount of (1) is from 0.1 to 50 parts by mass in relationship with 100 parts by mass of (A). 11. Alkaline battery according to claim 9, in The average particle size of (1) is from 0.1 to 50 nm 12. Alkaline battery according to claim 9, in which (1) is one or more metal oxides selected from the group that consists of TiO 2, Bi 2 O 3, CuO, In 2 O 3, SnO2 and Nb2O5. 13. Alkaline battery according to claim 9, in which (A) are crosslinked polymer particles comprising, as one or more major constituent monomer units, (meth) acrylic acid and / or an alkali metal salt thereof using an allyl ether type crosslinking agent and / or a vinyl type crosslinking. 14. Alkaline battery according to claim 9, in which (A) are formed by a crosslinked polymer in the form of particles (a1) that has an average particle size of 100 to 2,000 µm and / or a crosslinked polymer in the form of fine particles (a2) which has an average particle size of 0.1 to 100 \ mum. 15. Alkaline battery according to claim 9, in which (A) are formed by a crosslinked polymer in the form of particles (a1 ') that have an average particle size of 100 to 1,000 µm and / or a crosslinked polymer in the form of fine particles (a2 ') that has an average particle size of 0.1 to 50 \ mum. 16. Alkaline battery according to claim 9, in which (A) are crosslinked polymer particles obtained using polymerization in aqueous solution.