JP5698067B2 - Thickener for alkaline batteries - Google Patents

Description

  The present invention relates to a thickener for an alkaline battery, an alkaline battery negative electrode composition containing the thickener, and an alkaline battery using the negative electrode composition.

Conventionally, an alkaline battery is composed of a negative electrode, a positive electrode agent, a separator that separates the negative electrode from the positive electrode, and a storage can that stores them. As the negative electrode composition, a high-concentration alkaline electrolyte (a high-concentration potassium hydroxide aqueous solution, and A composition containing zinc oxide or the like if necessary) and zinc powder and / or zinc alloy powder is used.
However, the composition has various problems such as high spinnability and difficulty in handling, easy precipitation of zinc powder and / or zinc alloy powder in the composition, and easy leakage of liquid from the battery. Therefore, for the purpose of solving these problems and improving battery productivity, a thickener such as a water absorbent resin in which poly (meth) acrylic acid (salt) is insolubilized with a crosslinking agent is added to the composition. Has been proposed (see, for example, Patent Document 1).

JP 2008-34379 A

However, the above-mentioned composition to which a thickener such as a water absorbent resin is added is difficult to be poured into the storage can due to excessive thickening, and the spinnability resulting from the alkaline electrolyte remains, and the battery manufacturing process. However, there is a problem that production efficiency is poor. In addition, there is a problem that the retention property of the alkaline electrolyte of the negative electrode composition (the property that the alkaline electrolyte is stably and uniformly present in the composition without separation) is insufficient. Furthermore, there is a problem that the dispersion stability of the zinc powder and / or zinc alloy powder of the negative electrode composition is insufficient. Development of a thickener and a negative electrode composition that can solve these problems is eagerly desired.
An object of the present invention is a negative electrode composition having good dispersion stability of zinc powder and / or zinc alloy powder, good injectability into a negative electrode container, no spinnability, and excellent alkaline electrolyte retention. And a long-term discharge characteristic (a large discharge amount and a long discharge time), a thickener for an alkaline battery that gives an alkaline battery excellent in vibration shock resistance, a negative electrode composition containing the thickener, and the negative electrode composition An object of the present invention is to provide an alkaline battery using an object.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have reached the present invention. That is, this invention contains the polymer (A) which has the following ethylenically unsaturated monomer (a1) and / or the following ethylenically unsaturated monomer (a2), and the following ethylenically unsaturated monomer (a3) as an essential structural unit. And the thickener for alkaline batteries which satisfies the following requirements (1) and (2).
Ethylenically unsaturated monomer (a1): An ethylenically unsaturated monomer having at least one anionic group selected from the group consisting of a carboxyl group, a sulfo group and a phosphate group.
Ethylenically unsaturated monomer (a2): a salt of (a1) and an alkali metal and / or onium cation.
Ethylenically unsaturated monomer (a3): a salt of (a1) and a divalent or higher valent metal ion (b).
Requirement (1): The molar ratio (Q) in (A) determined by the following mathematical formula (1) is 0.0001-1.
Molar ratio (Q) = Σ (Ta × Ua) / S (1)
[In Formula (1), S is the total number of moles of anion groups and anion bases of (a1), (a2) and (a3), Ta is the number of moles of each metal ion (b) in (A), and Ua is It represents the ionic valence of each metal ion (b). ]
Requirement (2): The viscosity at 25 ° C. of the mixed solution after the thickener for alkaline battery and the 40 wt% potassium hydroxide aqueous solution are stirred and mixed at a weight ratio of 1/99 for 1 hour and left to stand at 40 ° C. for 24 hours ( V1) is 50 to 5,000 mPa · s.

Moreover, the alkaline battery negative electrode composition of the present invention is an alkaline battery negative electrode composition comprising an alkaline electrolyte, zinc powder and / or zinc alloy powder and the thickener of the present invention.
Furthermore, the alkaline battery of the present invention includes a negative electrode formed by filling the negative electrode composition of the present invention in a negative electrode container, a positive electrode agent, a separator separating the negative electrode and the positive electrode agent, and a current collecting rod enclosed in these storage cans. It is an alkaline battery.

When the thickener of the present invention is used as a thickener for alkaline batteries, the following effects are exhibited.
(1) Excellent dispersion stability of zinc powder and / or zinc alloy powder.
(2) Good injectability into storage cans, no stringiness and excellent production efficiency.
(3) Excellent retention of alkaline electrolyte.
(4) Excellent long-term discharge characteristics (discharge amount and discharge time) and vibration shock resistance.

[Polymer (A)]
The polymer (A) in the present invention comprises the following ethylenically unsaturated monomer (a1) and / or the following ethylenically unsaturated monomer (a2) and the following ethylenically unsaturated monomer (a3) as essential constituent units. .
Ethylenically unsaturated monomer (a1): An ethylenically unsaturated monomer having at least one anionic group selected from the group consisting of a carboxyl group, a sulfo group and a phosphate group.
Ethylenically unsaturated monomer (a2): a salt of (a1) and an alkali metal and / or onium cation.
Ethylenically unsaturated monomer (a3): a salt of (a1) and a divalent or higher valent metal ion (b).

  Examples of (a1) include anionic vinyl monomers (vinyl monomers having at least one group selected from the group consisting of a carboxyl group, a sulfo group, and a phosphate group) described in JP-A-2005-075982.

Examples of the vinyl monomer having a carboxyl group (a11) include unsaturated carboxylic acid [monocarboxylic acid [carbon number (hereinafter abbreviated as C) 3 to 10, for example, (meth) acrylic acid, crotonic acid, cinnamic acid]; Saturated dicarboxylic acids (C4-30, such as maleic acid, fumaric acid, citraconic acid, itaconic acid); monoalkyl (C1-8) esters of unsaturated dicarboxylic acids (C5-30, such as maleic acid monobutyl ester, fumaric acid mono Butyl ester, ethyl carbitol maleate monoester, ethyl carbitol monoester of fumaric acid, citraconic acid monobutyl ester, itaconic acid glycol monoester) and the like, and mixtures thereof.
In the present invention, (meth) acrylic acid means acrylic acid and / or methacrylic acid, and "... acid (salt)" means "... acid" and / or "... acid salt". "Means.

  Examples of the vinyl monomer (a12) having a sulfo group include aliphatic and aromatic vinyl sulfonic acids [C2-30, such as vinyl sulfonic acid, (meth) allyl sulfonic acid, styrene sulfonic acid, α-methylstyrene sulfonic acid]. ; (Meth) acryloxyalkylsulfonic acid [C4-30, such as (meth) acryloxypropylsulfonic acid, 2-hydroxy-3- (meth) acryloxypropylsulfonic acid, 2- (meth) acryloylamino-2,2 -Dimethylethanesulfonic acid, 3- (meth) acryloxyethanesulfonic acid, 2- (meth) acrylamino-2-methylpropanesulfonic acid, 3- (meth) acrylamino-2-hydroxypropanesulfonic acid]; alkyl ( C3-18) (meth) allylsulfosuccinate [C10-24 For example propyl (meth) allyl sulfosuccinate], and mixtures thereof.

  Examples of the vinyl monomer (a13) having a phosphoric acid group include (meth) acryloxyalkane (alkane is C2-6) phosphonic acid [2- (meth) acryloxyethanephosphonic acid and the like] and mixtures thereof. It is done.

  Among these (a1), from the viewpoint of discharge characteristics of an alkaline battery, C3-30 unsaturated carboxylic acid is preferable, unsaturated monocarboxylic acid is particularly preferable, and (meth) acrylic acid is most preferable.

The ethylenically unsaturated monomer (a2) is a salt of (a1) and an alkali metal and / or onium cation.
Examples of the alkali metal cation include Na ⁺ and K ⁺ .
Examples of onium include those described in JP-A Nos. 2003-251178 and 2005-95357, and examples of onium cations include quaternary ammonium cations (I) and tertiary phosphonium cations ( II), quaternary phosphonium cation (III), tertiary oxonium cation (IV), alkylpyridinium cation (V), ammonium cation (VI) excluding (I) above {primary, secondary, primary A tertiary ammonium cation, for example, a C1-10 amine (methylamine, dimethylamine, etc.) with a proton added}, etc. (hereinafter the term cation is omitted).
In the present invention, two or more of these cations may be used.
Among the above cations, alkali metal cations are preferable from the viewpoint of discharge characteristics of an alkaline battery, and Na ⁺ and K ⁺ are more preferable.
Among (a2), from the viewpoint of discharge characteristics of alkaline batteries, C3-30 unsaturated carboxylates are preferred, unsaturated monocarboxylates are more preferred, and (meth) acrylic acid is particularly preferred. Salts, most preferred are sodium (meth) acrylate and potassium (meth) acrylate.

The ethylenically unsaturated monomer (a3) is a salt of (a1) and a divalent or higher metal ion (b).
Examples of the divalent or higher valent metal ion (b) include divalent metal ions [IIA group (Be ²⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ etc.), IIB group (Zn ^{2 +,} Etc.), IVB group (Ti ²⁺ etc.), VIIB group (Mn ²⁺ etc.), VIII group (Fe ²⁺ , Co ²⁺ etc.), etc.], trivalent metal ion [IB group (Au ³⁺ etc.) ), VA group (Bi ³⁺ etc.), IIIA group (Al ³⁺ etc.), VIII group (Fe ³⁺ etc.), etc.], tetravalent metal ions [IVB group (Ti ⁴⁺ etc.), IIB group (Zn ⁴⁺ etc.)] and the like.
Two or more kinds of these metal ions (b) may be used in combination.
Among these, those having a higher ionization tendency than zinc from the viewpoint of reducing gas generation in alkaline batteries {for example, divalent (IIA group, IVB group, VIIB group) metal ions and trivalent (IIIA group) metal ions, etc.} From the viewpoint of retention of the alkaline electrolyte, metal ions of Group IIA, Group IVB and Group IIIA are more preferable, and Mg ²⁺ , Ca ²⁺ , Al ³⁺ and Ti ²⁺ are particularly preferable. .

  The ethylenically unsaturated monomer (a3) is prepared by adding a hydroxide and / or salt of the metal ion (b) to (a1) and / or (a2) and neutralizing or exchanging the salt. Can do. Further, the hydroxide and / or salt of the metal ion (b) is added to the polymer of the monomer containing (a1) and / or (a2), and neutralized or salt-exchanged to obtain (a1) and / or Or the polymer (A) which has (a2) and (a3) as an essential structural unit can be created.

  As the hydroxide of the metal ion (b) used for the neutralization, from the viewpoint of reducing the gas generation of the alkaline battery, the metal ion hydroxide and trivalent of divalent (IIA group, IVB group, VIIB group) are used. (IIIA) metal ion hydroxides are preferred, and magnesium hydroxide, calcium hydroxide, aluminum hydroxide and titanium hydroxide are more preferred.

Regarding the salt of the metal ion (b) used for the salt exchange, examples of the counter anion include a halogen ion (F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ etc.), a carboxylate anion {containing a carboxyl group of C1 to 10 Compound ion (—COO ⁻ )}, phosphate ion {phosphoric acid or C 1-10 phosphate group-containing compound ion (—OPO ₃ ²⁻ )} and sulfonate ion {sulfonic acid or C 1-10 sulfo group Ions (—SO ₃ ⁻ )} of the containing compound and the like.
Among these anions, a carboxylate anion is preferable from the viewpoint of discharge performance.
Moreover, as a salt, the C1-10 carboxylate is preferable from a viewpoint of discharge performance.

As the hydroxide and / or salt of (b), two or more kinds may be used. When using 2 or more types, you may use 1 or more types, respectively, may use 2 or more types of hydroxides, and may use 2 or more types of chlorides.
Of the hydroxides and salts of (b), magnesium hydroxide, calcium hydroxide and aluminum hydroxide are preferred from the viewpoint of reducing gas generation in alkaline batteries.

  When one molecule of the ethylenically unsaturated monomer has a plurality of anionic groups, when at least one of the anionic groups forms a salt with the metal ion (b), it is (a3). And Further, when it is not (a3) and at least one of anionic groups forms a salt with the alkali metal and / or cation of onium, it is assumed to be (a2). What is neither (a3) nor (a2) is (a1).

The content (% by weight) of (a1) in the polymer (A) is 0.0000001 based on the total weight of (a1), (a2) and (a3) from the viewpoint of the retention of the alkaline electrolyte. ˜99.999 is preferred, more preferably 10-99.995.
The content (% by weight) of (a2) in the polymer (A) is 0.0000001 based on the total weight of (a1), (a2) and (a3) from the viewpoint of the retention of the alkaline electrolyte. ˜99.999 is preferred, more preferably 10-99.995.
The content (% by weight) of (a3) in the polymer (A) is 0.001 based on the total weight of (a1), (a2) and (a3) from the viewpoint of the retention of the alkaline electrolyte. To 99.9999999, more preferably 0.001 to 99.99999998, next more preferably 0.005 to 90, and particularly preferably 0.005 to 80.

  The polymer (A) can further contain other water-soluble ethylenically unsaturated monomers (a4) as structural units. Here and below, water-soluble refers to the property of dissolving 100 g or more in 100 g of water at 25 ° C.

  The water-soluble ethylenically unsaturated monomer (a4) is not particularly limited as long as it is a monomer copolymerizable with (a1) to (a3). However, the vinyl monomer [1,1 described in JP-A-2005-075982 At least one selected from the group consisting of 3-oxo-2-oxapropylene (—CO—O—CO—) group, ester group, cyano group, phosphate ester group, amide group, amino group, ammonium group and hydroxyl group Vinyl monomers having a functional group of

  Examples of the vinyl monomer (a41) having a 1,3-oxo-2-oxapropylene group include C4-20 unsaturated carboxylic acid anhydrides such as maleic anhydride, itaconic anhydride, and citraconic anhydride. Be

  As the vinyl monomer (a42) having an ester group, for example, an unsaturated carboxylic acid alkyl (alkyl group is C1-50) ester [C4-60, such as methyl (meth) acrylate, ethyl (meth) acrylate, maleic acid Dimethyl, diethyl itaconate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, eicosyl (meth) acrylate]; Unsaturated alcohol (C2-3) carboxylic acid ester [C4-20, for example, vinyl acetate, acetic acid (meth) allyl], etc. are mentioned.

  As a vinyl monomer (a43) which has a cyano group, the C3-15 thing is contained, for example, (meth) acrylonitrile, cyanostyrene, etc. are mentioned.

  As the vinyl monomer (a44) having a phosphate ester group, for example, (meth) acryloxyalkane (alkane is C2-6) phosphate monoester [(meth) acryloxyethane phosphate monoester etc.] (meth) acrylic Roxyalkanes (alkanes are C2-6) phosphoric acid diesters [bis (2-acryloxyethane) phosphoric acid diesters and the like] and the like.

  Examples of the vinyl monomer (a45) having an amide group include those having C3-20, such as (meth) acrylamide, N-alkyl (C1-8) (meth) acrylamide [N-methylacrylamide, etc.]; N, N -Dialkyl (C1-8) (meth) acrylamide [N, N-dimethyl (meth) acrylamide, etc.]; N-hydroxyalkyl (C1-8) (meth) acrylamide [N-methylol (meth) acrylamide, N-hydroxy Ethyl (meth) acrylamide etc.]; N, N-dihydroxyalkyl (C1-8) (meth) acrylamide [N, N-dihydroxyethyl (meth) acrylamide etc.]; vinyl lactam [N-vinylpyrrolidone etc.] and the like. .

  As the vinyl monomer (a46) having an amino group, for example, a heterocyclic vinyl compound (C7-12, such as 2-vinylpyridine, 4-vinylpyridine, N-vinylpyridine, N-vinylimidazole, etc.); C2-10) unsaturated carboxylic acid amide [C5-18, such as aminoethyl (meth) acrylamide, aminopropyl (meth) acrylamide]; dialkyl (C1-8) aminoalkyl (C2-10) unsaturated carboxylic acid amide [C7 -30, such as dimethylaminoethyl (meth) acrylamide]; dihydroxyalkyl (C1-8) aminoalkyl (C2-10) unsaturated carboxylic acid amide [C7-30, such as di (hydroxymethyl) aminoethyl (meth) acrylic acid Amide]; morpholinoalkyl (alkyl is C -8) unsaturated carboxylic acid amides [C8-20, such as morpholinoethyl (meth) acrylic acid amides]; aminoalkyl unsaturated carboxylic acid esters [C5-15, such as aminoethyl (meth) acrylates]; dialkyls (C1-8) ) Aminoalkyl (C2-10) unsaturated carboxylic acid ester [C6-24, eg dimethylaminoethyl (meth) acrylate, dimethylaminoethyl fumarate]; dihydroxyalkyl (C1-8) aminoalkyl (C2-10) unsaturated Carboxylic acid esters [C7-24, such as di (hydroxymethyl) aminoethyl (meth) acrylate]; Morpholinoalkyl (alkyl is C1-8) unsaturated carboxylic acid ester [C8-20, such as morpholinoethyl (meth) acrylate]; Examples include diallylamine It is.

  As the vinyl monomer having an ammonium group (a47), the above vinyl monomer having an amino group may be an acid [inorganic acid (hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, perbromic acid, etc.), an organic acid (C1 to C1). 4, neutralized salt neutralized with, for example, formic acid, acetic acid, propanoic acid, lactic acid, malic acid, citric acid, etc.]; (a14) is an alkylating agent [alkyl halide (C1-8, such as methyl chloride, benzyl chloride) ), Alkyl sulfate (C2-8, such as dimethyl sulfate, diethyl sulfate), alkyl carbonate (C2-8, such as dimethyl carbonate, diethyl carbonate), alkylene oxide (C2-3, such as ethylene oxide, propylene oxide)] and the like. Quaternized quaternary ammonium salts [trimethylammonioethyl (meth) acrylate chloride Methyl diethyl ammonio ethyl (meth) acrylate methosulfate, trimethylammonioethyl (meth) acrylamide chloride and diethyl benzyl ammonio ethyl (meth) acrylamide chloride, etc.] and the like.

  Examples of the vinyl monomer (a48) having a hydroxyl group include monovalent ethylenically unsaturated alcohol [C3-6, such as (meth) allyl alcohol]; 2-6 valent polyol {C2-20, such as alkylene glycol [ethylene. Glycol, propylene glycol, triethylene glycol (hereinafter abbreviated as EG, PG, TEG, etc.), glycerin (hereinafter abbreviated as GR), polyoxyalkylene (alkylene is C2-4) glycol [molecular weight of 106 or more and number average molecular weight [ Hereinafter abbreviated as Mn. The measurement is based on a gel permeation chromatography (GPC) method. ] 2,000 or less]} (meth) acrylate [TEG (meth) acrylate, poly (oxyethylene / oxypropylene) (random and / or block) glycol (Mn200 to 2,000) mono (meth) allyl ether, etc.] And mixtures thereof.

  In the polymer (A), the weight ratio of the total weight of (a1), (a2) and (a3) constituting the polymer (A) to the weight of (a4) [{(a1) + (a2) + ( a3)} / (a4)] is preferably 75/25 to 100/0, more preferably 85/15 to 100/0, particularly preferably from the viewpoint of the discharge characteristics of the alkaline battery and the absorption performance of the polymer (A). Is 90/10 to 100/0.

In the polymer (A), another vinyl monomer (a5) that can be further copolymerized can be added to the structural unit. (A5) is not particularly limited, and a hydrophobic vinyl monomer or the like known in the art {Patent No. 3648553, JP-A No. 2003-165883, JP-A No. 2005-75982 and JP-A No. 2005-95759} is used. The following vinyl monomers (i) to (iii) can be used.
(I) C8-C30 aromatic ethylenic monomer Styrene such as styrene, α-methylstyrene, vinyltoluene and hydroxystyrene, and halogen substituted products of styrene such as vinylnaphthalene and dichlorostyrene.
(Ii) C2-C20 aliphatic ethylene monomer Alkene [ethylene, propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene, etc.]; and alkadiene [butadiene, isoprene, etc.], etc.
(Iii) C5-C15 alicyclic ethylene monomer Monoethylenically unsaturated monomer [pinene, limonene, indene and the like]; and polyethylene vinyl polymerizable monomer [cyclopentadiene, bicyclopentadiene, ethylidene norbornene and the like] and the like.

  In the polymer (A), the content (mol%) of (a5) is based on the total number of moles of (a1), (a2), (a3), (a4) and (a5) from the viewpoint of reactivity. The content is preferably 0 to 5 mol%, more preferably 0 to 3 mol%, then preferably 0 to 2 mol%, particularly preferably 0 to 1.5 mol%.

  The polymer (A) has the above (a1) and / or (a2) and (a3) as essential constituent units, but when (A) is a crosslinked polymer, it further constitutes an internal crosslinking agent (c1). Can be added to the unit. Examples of (c1) include a hydrolyzable crosslinking agent (c11) that is hydrolyzed under alkaline conditions and a non-hydrolyzable crosslinking agent (c12) that is not hydrolyzed under the same conditions.

  As the hydrolyzable crosslinking agent (c11), a crosslinking agent having a hydrolyzable bond (amide bond, ester bond, etc.) in the molecule {a copolymerizable crosslinking agent having a divalent to 10-valent ethylenically unsaturated bond [ C4-30, for example, divalent [N, N′-methylenebisacrylamide, EG di (meth) acrylate, trimethylolpropane (hereinafter abbreviated as TMP) di (meth) acrylate, pentaerythritol (hereinafter abbreviated as PE) di (meta] ) Acrylate, etc.], trivalent [TMP tri (meth) acrylate, PE tri (meth) acrylate, etc.], tetravalent [PE tetra (meth) acrylate, etc.], and divalent or higher polyGR (degree of polymerization 3 to 3). 13) Polyacrylate and a mixture of two or more thereof]; bonds formed by crosslinking (ester bonds, amide bonds, etc.) are hydrolyzed Crosslinkers [ester-forming reactive crosslinkers [C2-100, such as polyvalent (2-3 or more) glycidyl compounds (EG diglycidyl ether, etc.), polyvalent (2-3) isocyanate (4, 4′-diphenylmethane diisocyanate, etc.), polyvalent (2-3) amine (ethylenediamine, etc.), polyvalent (2-3 or more) alcohol (GR, etc.)]; and mixtures of two or more of these Can be mentioned. The reactive crosslinking agent reacts with the carboxyl group of (a1) and the like to form an ester bond or an amide bond.

The non-hydrolyzable crosslinking agent (c12) is a crosslinking agent that does not have a hydrolyzable bond in the molecule and does not generate a hydrolyzable bond by a crosslinking reaction.
(C12) is a crosslinking agent having two or more vinyl ether bonds (c121) [C2-100, such as EG divinyl ether, 1,4-butanediol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, 1, 6-hexanediol divinyl ether, polyethylene glycol (hereinafter abbreviated as PEG) divinyl ether (polymerization degree 2-5), bisphenol A divinyl ether, PE trivinyl ether, sorbitol trivinyl ether, polyGR (polymerization degree 3-13) polyvinyl ether, etc. ] A crosslinking agent (c122) having two or more allyl ether bonds, and a mixture thereof.

  The crosslinking agent (c122) having two or more allyl ether bonds includes a crosslinking agent (c1221) having two allyl groups and no hydroxyl group in the molecule, two allyl groups in the molecule, and Cross-linking agent having 1 to 5 hydroxyl groups (c1222), cross-linking agent having 3 to 10 allyl groups in the molecule and no hydroxyl groups (c1223), 3 to 10 allyl groups in the molecule And a crosslinking agent (c1224) having 1 to 3 hydroxyl groups. When it has a hydroxyl group in the molecule, it is compatible with (a1) and / or (a2) and (a3) [especially (meth) acrylic acid (salt)], and the thickener is stabilized by uniform crosslinking. This improves the long-term stability of the viscosity of the alkaline electrolyte containing the thickener.

Examples of the crosslinking agent (c1221) having two allyl groups in the molecule and no hydroxyl group include diallyl ether, 1,4-cyclohexanedimethanol diallyl ether, alkylene (C2-5) glycol diallyl ether, and PEG [ Weight average molecular weight [hereinafter abbreviated as Mw. The measurement is based on a gel permeation chromatography (GPC) method. ] 100-4,000)] diallyl ether and the like.
As a crosslinking agent (c1222) having 2 allyl groups and 1 to 5 hydroxyl groups in the molecule, GR diallyl ether, TMP diallyl ether, PE diallyl ether, polyGR (degree of polymerization 2 to 5) diallyl ether Etc.

Examples of the cross-linking agent (c1223) having 3 to 10 allyl groups in the molecule and not having a hydroxyl group include TMP triallyl ether, GR triallyl ether, PE tetraallyl ether, and tetraallyloxyethane. .
As a crosslinking agent (c1224) having 3 to 10 allyl groups and 1 to 3 hydroxyl groups in the molecule, PE triallyl ether, diGR triallyl ether, sorbitol triallyl ether, polyGR (degree of polymerization) 3-13) and polyallyl ether.
Among these (c12), from the viewpoint of reactivity and compatibility with the ethylenically unsaturated monomers (a1) to (a3), (c122) is preferable, and TMP diallyl ether, PE di- and tri- are more preferable. Allyl ether.

Among these internal cross-linking agents (c1), (c11), (c12), and mixtures thereof are preferable from the viewpoint of retention of the alkaline electrolyte.

The proportion of (c1) is preferably 0.01 to 2 weights based on the total weight of (a1), (a2) and (a3), from the viewpoint of the retention of the alkaline electrolyte and the long-term discharge characteristics of the alkaline battery. %, More preferably 0.03 to 1% by weight, particularly preferably 0.05 to 0.5% by weight.
Further, the ratio of (c1) is based on the total weight of the ethylenically unsaturated monomers (a1), (a2), (a3) and (a4), and the alkaline electrolyte retainability and the long-term discharge characteristics of the alkaline battery. From the viewpoint, it is preferably 0.01 to 2% by weight, more preferably 0.03 to 1% by weight, and particularly preferably 0.05 to 0.5% by weight.

The manufacturing method of the polymer (A) in this invention is demonstrated below.
As the production method of (A), various polymerization methods including known ones such as solution polymerization, suspension polymerization, bulk polymerization, reverse phase suspension polymerization and emulsion polymerization can be applied.
Among these polymerization methods, from the viewpoint of obtaining a thickener that contributes to the long-term discharge characteristics and vibration shock resistance of alkaline batteries, aqueous polymerization, suspension polymerization, reverse phase suspension polymerization, emulsion polymerization, Preferred are aqueous solution polymerization, reverse phase suspension polymerization, and emulsion polymerization, and particularly preferred are aqueous solution polymerization and reverse phase suspension polymerization. For these polymerizations, known polymerization initiators, chain transfer agents and / or solvents can be used.

  A monomer component obtained by adding the above-described ethylenically unsaturated monomer {(a1), (a2), (a3), (a4) and (a5) etc.} and an internal cross-linking agent (c1), which is a constituent component, to an aqueous solution polymerization method Or the method of polymerizing by the reverse phase suspension polymerization method may be a normal method, for example, a method of polymerizing using a radical polymerization initiator, a method of polymerizing by irradiating active energy rays such as radiation, ultraviolet rays or electron beams. Can be mentioned.

  Examples of radical polymerization initiators include azo compounds [azobisisovaleronitrile, azobisisobutyronitrile, 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis [2-methyl-N -(2-hydroxyethyl) propionamide, 2,2'-azobis (2-amidinopropane) hydrochloride, etc.], inorganic peroxides [hydrogen peroxide, potassium persulfate, ammonium persulfate, sodium persulfate, etc.], organic Peroxides (di-t-butyl peroxide, cumene hydroperoxide, etc.), redox initiators (reducing agents (alkali metal salts (bi) sulfite, (bi) ammonium sulfite, L-ascorbic acid, etc.) and hydrogen peroxide) Combinations with oxides (persulfates of alkali metal salts, ammonium persulfate, hydrogen peroxide, etc.)], and these two types Of the combination, and the like more.

The polymerization temperature varies depending on the type of radical polymerization initiator used and the like, but is preferably −10 to 100 ° C., more preferably −5 to 80 ° C. from the viewpoint of the polymerization rate and the degree of polymerization.
The amount of the radical polymerization initiator used is preferably 0.000001 to 3% by weight, more preferably 0.000001 to 0.5% by weight, from the viewpoint of the degree of polymerization, based on the total weight of the monomers.
Although the amount of dissolved oxygen during polymerization depends on the amount of radical polymerization initiator used, etc., it is preferably 0 to 2 ppm, more preferably 0 to 0.5 ppm from the viewpoint of a high degree of polymerization.

  In the case of aqueous solution polymerization, the monomer concentration (% by weight) varies depending on other polymerization conditions, but the polymerization reaction rate and polymerization temperature controllability, inhibition of monomer self-crosslinking, improvement in polymerization degree, inhibition of oligomer component formation From this viewpoint, it is preferably 10 to 40%, more preferably 10 to 30%.

  When (meth) acrylic acid is used as the polymerization monomer, the degree of neutralization is not particularly limited as long as a predetermined amount of the internal crosslinking agent (c1) to be added can be completely dissolved in the aqueous monomer solution. ) From the viewpoint of the degree of polymerization of acrylic acid and the solubility of (c1), (meth) acrylic acid is preferably polymerized at a degree of neutralization of 0 to 30 mol%, and if necessary, further neutralized after polymerization. It is more preferable to neutralize after the polymerization if necessary after the polymerization in the state of sum.

  The reverse phase suspension polymerization method is a polymerization method in which an aqueous monomer solution is suspended and dispersed in a hydrophobic organic solvent such as hexane, toluene, xylene in the presence of a dispersant, and the monomer in this polymerization method is used. The monomer concentration (% by weight) in the aqueous solution is preferably 10 to 50%, more preferably 10 to 40% from the same viewpoint as the aqueous solution polymerization.

In the reverse phase suspension polymerization method, a dispersant may be used during the polymerization. Dispersants include surfactants having a glycine HLB (Hydrophile-Lipophile Balance) of 3 to 8 [sorbitan fatty acid esters (such as sorbitan monostearic acid ester), GR fatty acid esters (such as GR monostearic acid ester), sucrose fatty acid Ester (sucrose distearate, etc.)]; a polymer dispersant having a hydrophilic group in the molecule and soluble in a solvent for dispersing the aqueous monomer solution (content ratio of hydrophilic group 0.1 to 20) % By weight, weight average molecular weight 1,000-1,000,000) [methyleneated ethylene / acrylic acid copolymer, maleated ethylene / vinyl acetate copolymer, styrenesulfonic acid (salt) / styrene copolymer Etc.].
Among these, a polymer dispersant is preferable from the viewpoint of controlling the particle diameter of the polymer (A).
In addition, HLB means that hydrophilicity is so high that a value is high, and is a numerical value calculated by the following formula (Written by Fujimoto Takehiko, Introduction to Surfactant, page 142, published by Sanyo Chemical Industries, Ltd.).
HLB = 20 × {molecular weight of hydrophilic group / molecular weight of surfactant}

The addition amount of the dispersant is preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight, based on the weight of the hydrophobic organic solvent, from the viewpoint of long-term discharge characteristics of the alkaline battery.
The weight ratio (W / O ratio) between the aqueous monomer solution and the hydrophobic organic solvent in the reverse phase suspension polymerization is preferably 0.1 to 2.0, more preferably from the viewpoint of controlling the particle diameter of the polymer (A). Preferably it is 0.3-1.0.

In the production of the polymer (A), the weight average molecular weight of the polymer when the polymer was produced without using the internal crosslinking agent (c1) [measurement is based on the gel permeation chromatography (GPC) method. ] Is preferably 5,000 to 1,000,000, more preferably 10,000 to 1,000,000, from the viewpoint of the discharge characteristics of the alkaline battery and the absorption performance of the polymer (A).
When the internal crosslinking agent (c1) is used in combination as a polymerization monomer under polymerization conditions where the weight average molecular weight is 5,000 or more, the thickener of the present invention containing the resulting polymer (A) is used for an alkaline battery. And prevention of the viscosity fall of alkaline electrolyte can be aimed at.

The polymer (A) produced by aqueous solution polymerization, reverse phase suspension polymerization or the like is usually obtained as a gel containing water (hydrous gel). The hydrogel is usually used as a thickener after it is dried.
As a drying method of the hydrogel, in the case of aqueous solution polymerization, the hydrogel is subdivided into an appropriate size using a meat chopper or a cutter type crusher (the level of subdivision is usually 0.5 to 20 mm square). Grade) or noodles, neutralize the hydrogel by adding alkali metal hydroxide, etc. if necessary, and then air-drying (lamination of the hydrogel on a punching metal or screen and hot air at 50 to 150 ° C. Drying method that forcibly vents air) and air-drying (drying method in which a hydrogel is placed in a container and hot air is ventilated and circulated, or the gel is further subdivided with a machine such as a rotary kiln) The method is mentioned. Among these, air-permeable drying is preferable from the viewpoint of efficient drying in a short time.
On the other hand, as a drying method of the hydrogel in the case of reverse phase suspension polymerization, the obtained hydrogel and the hydrophobic organic solvent are solid-liquid separated by a method such as decantation, and then dried under reduced pressure (degree of vacuum 100 to 50, 000 Pa) or air drying is common.

In the present invention, when the polymer (A) is produced, the monomer (a3) is added by adding the hydroxide and / or salt of (b) to the monomer (a1) and / or (a2). Polymerization may be carried out after the monomer has been produced, or a monomer containing (a1) and / or (a2) is polymerized to produce a hydrogel of the polymer (A ′), and then the polymer (A ′) You may add the hydroxide and / or salt of (b) after the process of neutralizing a water-containing gel, or drying the water-containing gel of a polymer (A ').
Among these, from the viewpoint of retention of the alkaline electrolyte, it is preferable to add the hydroxide and / or salt of (b) into the monomer and / or the hydroxide and / or salt of (b). It is adding in the neutralization process of the hydrogel of a polymer (A '), and the addition in the neutralization process of a hydrogel is more preferable.

  The amount of residual monomer in the obtained polymer (A) is preferably 2,000 ppm or less, more preferably 1,000 ppm or less, and particularly preferably 500 ppm or less from the viewpoint of discharge characteristics of the alkaline battery.

[Thickener for alkaline batteries]
The thickener for alkaline batteries of this invention contains the said polymer (A), and satisfies the following requirements (1) and (2).
Requirement (1): The molar ratio (Q) in (A) determined by the following mathematical formula (1) is 0.0001-1.
Molar ratio (Q) = Σ (Ta × Ua) / S (1)
[In Formula (1), S is the total number of moles of anion groups and anion bases of (a1), (a2) and (a3), Ta is the number of moles of each metal ion (b) in (A), and Ua is It represents the ionic valence of each metal ion (b). ]
Requirement (2): Thickener for alkaline battery and 40% by weight aqueous potassium hydroxide solution are stirred and mixed at a weight ratio of 1/99 until uniform, and allowed to stand at 40 ° C. for 24 hours. The viscosity (V1) is 50 to 5,000 mPa · s.

  The molar ratio (Q) of the above requirement (1) is preferably 0.0008 to 1, more preferably 0.01 to 0.99999, next more preferably 0.02 to 0.9999, particularly preferably 0.00. 05 to 0.999, most preferably 0.09 to 0.99. When the molar ratio (Q) is less than 0.0001, the retention property of the alkaline electrolyte and the long-term discharge characteristics of the battery are deteriorated.

Although the thickener for alkaline batteries of this invention contains a polymer (A), you may have the hydroxide (D1) and / or salt (D2) of a metal ion (b) further.
As the hydroxide (D1) and / or salt (D2) of the metal ion (b), those exemplified as those used for the neutralization or salt exchange described above can be used.
The content (% by weight) of the hydroxide (D1) and / or salt (D2) of the metal ion (b) in the thickener for the alkaline battery is the viewpoint of the retention property of the alkaline electrolyte and the long-term discharge characteristics of the battery. From 0 to 50% by weight, preferably 0 to 30% by weight, based on the weight of the thickener.
The content (% by weight) of the polymer (A) in the thickener for alkaline batteries is preferably 50 to 100% by weight, more preferably 70%, from the viewpoints of retention of the alkaline electrolyte and long-term discharge characteristics of the battery. ~ 100% by weight.

Further, the thickener for an alkaline battery of the present invention has a molar ratio (R) between the metal ion (b) in the thickener and the anionic group in the polymer (A), which is obtained by the following mathematical formula (2). From the viewpoint of retention of the alkaline electrolyte and long-term discharge characteristics of the battery, it is preferably 0.0001 to 4, more preferably 0.001 to 2, and particularly preferably 0.01 to 1.
Molar ratio (R) = Σ (Oa × Pa) / S (2)
[In Formula (2), S is the total number of moles of anionic groups and anionic bases of (a1), (a2) and (a3) in (A), Oa is the number of each metal ion (b) in the thickener. The number of moles, Pa, represents the ionic valence of each metal ion (b). ]

  Further, a metal ion (b) having a valence of 2 or more in the thickener for an alkaline battery [metal ion (b) in the polymer (A) and (D) {(D1) and (D2)} contained in the metal The total amount of metal elements (B) (% by weight) of [total amount of] is preferably from 0.0001 to 80% by weight, more preferably from 0.02 to 75% by weight, based on the weight of the thickener for alkaline batteries. Next, it is more preferably 0.04 to 50% by weight, particularly preferably 1 to 20% by weight. When (B) is 0.01% by weight or more, the retention property of the alkaline electrolyte and the long-term discharge characteristics of the battery are improved, and when it is 80% by weight or less, the negative electrode composition described later is injected into the negative electrode container. Becomes better.

  The measurement of (B) can be measured by analyzing the element content of the thickener using, for example, a fluorescent X-ray analyzer (XRF). The measurement method conforms to JIS K 0119-2008, and is specifically as follows.

<X-ray fluorescence analysis>
As the measuring apparatus, a wavelength dispersion type X-ray fluorescence analyzer “Axios” (manufactured by PANalytical) and attached dedicated software “UniQuant 5” (manufactured by PANalytical) for setting measurement conditions and analyzing measurement data are used. The measurement atmosphere is vacuum and the measurement diameter (collimator mask diameter) is 27 mm.

As a measurement sample, about 3 g of thickening agent is put in a special vinyl chloride for press and flattened, and 20 tons using a tablet molding compressor “BRIQUETING MACHINE MP-35” (manufactured by Shimadzu Corporation). Then, a pellet formed by pressing for 10 seconds and molding to a thickness of about 2.5 mm and a diameter (outer diameter) of about 40 mm is used.
When the particle size of the measurement sample is coarse, it is difficult to mold the sample. After pulverizing using a pulverizer “VIBRATING SAMPLE MILL T1-100” (CMT MT CO. LTD.), Add the pulverized thickener and mold.

Measurement is performed under the above conditions, and the amount of each element (% by weight) is calculated. From this value, the total metal element amount (B) (% by weight) is calculated by the following formula. In addition, the measurement sample used for the measurement of (B) uses the sample which dried at 105 degreeC in the normal wind dryer, and became constant weight.
Total amount of metal elements (B) (wt%) = Σα _b
α _b : Element amount (% by weight) of each metal that can be a divalent or higher-valent metal ion in the thickener

In addition, as shown in the above requirement (2), the thickener for alkaline batteries of the present invention and a 40 wt% aqueous potassium hydroxide solution were stirred and mixed at a weight ratio of 1/99 for 1 hour and allowed to stand at 40 ° C. for 24 hours. The viscosity (V1) (mPa · s) at 25 ° C. of the later mixed liquid is 50 to 5,000, preferably 80 to 2,500, and more preferably 100 to 1,500.
When the viscosity is less than 50, the retention property of the alkaline electrolyte and the long-term discharge characteristics of the battery are deteriorated, and when it exceeds 5,000, the injectability of the negative electrode composition described later into the negative electrode container is deteriorated.
Here, the viscosity is 5 minutes after the start of measurement using a B-type viscometer [for example, model number “DVL-B II” manufactured by TOKIMEC Co., Ltd.] after adjusting the temperature to 25 ° C. by re-stirring the liquid mixture. It is a later value.
The viscosity (V1) can be controlled by adjusting the amount of the non-hydrolyzable crosslinking agent (c12), the particle diameter of the thickener, and the amount of the radical polymerization initiator. Decreasing the amount of non-hydrolyzable crosslinking agent (c12), reducing the particle size of the thickener when the thickener is powder, or reducing the amount of radical polymerization initiator during polymer production. The viscosity (V1) increases.

The ratio of the absorption capacity (K) of the thickener for alkaline batteries of the present invention to 40% by weight potassium hydroxide aqueous solution and the absorption capacity (H) to ion-exchanged water is determined by the retention of alkaline electrolyte and the long-term discharge of the battery. From the viewpoint of characteristics and injectability of the negative electrode composition described later into the negative electrode container, it is preferably 0.01 to 200, more preferably 0.1 to 100, and particularly preferably 0.4 to 80. Here, the absorption capacity is a value obtained by the following calculation formula.

Absorption rate = (weight of thickener after absorption of absorption target) / (weight of thickener before absorption of absorption target)

Each absorption rate with respect to 40 weight% potassium hydroxide aqueous solution and ion-exchange water is specifically measured by the following method.
(1) Measuring method of absorption capacity with respect to 40% by weight potassium hydroxide aqueous solution To a tea bag (20 cm long, 10 cm wide) made of nylon mesh having a mesh size of 63 μm (JIS Z8801-1: 2006) After 1.00 g of a measurement sample (thickening agent) with the particles cut is immersed in 1,000 ml of a 40 wt% aqueous potassium hydroxide solution without stirring at 25 ° C. for 24 hours, the tea bag is taken out. Measure the weight (W4) of the tea bag that was hung in an atmosphere of 25 ° C. and 50% RH for 30 minutes and drained.
The tea bag weight (W5) is measured in the same manner as described above except that the measurement sample (thickening agent) is not used.
The absorption capacity (g / g) with respect to 40% by weight potassium hydroxide aqueous solution is obtained from the following calculation formula.

Absorption capacity (K) = [(W4) − (W5)] / 1.00 with respect to 40 wt% potassium hydroxide aqueous solution
The absorption capacity (K) with respect to the 40 wt% potassium hydroxide aqueous solution can be controlled by adjusting the amount of the non-hydrolyzable crosslinking agent (c12). Increasing the amount of the non-hydrolyzable crosslinking agent (c12) decreases (K), and decreasing the amount of the non-hydrolyzable crosslinking agent (c12) increases (K).

(2) Measuring method of absorption capacity with respect to ion-exchanged water Except that 1.00 g of a measurement sample was replaced with 0.10 g of a 40 wt% potassium hydroxide aqueous solution and ion-exchanged water for 24 hours and 1 hour for immersion for 24 hours. ), The weight (W6) of the tea bag is measured.
The weight (W7) of the tea bag is measured in the same manner as above except that no measurement sample is used.
The absorption capacity (g / g) for ion-exchanged water is obtained from the following calculation formula.

Absorption capacity for ion-exchanged water (H) = [(W6) − (W7)] / 0.10
The absorption capacity (H) with respect to ion-exchanged water can be adjusted by the amount of internal crosslinking agent (c1) and the amount of surface crosslinking agent. When the amount of the crosslinking agent increases, (H) decreases, and when the amount of the crosslinking agent decreases, (H) increases.
Moreover, the amount of the metal ion (b) contained in the thickener can be adjusted and controlled. When the amount of metal ion (b) decreases, (H) increases, and when the amount of (b) increases, (H) decreases.
Further, when the proportion of the ethylenically unsaturated monomer (a2) in the polymer (A) increases, (H) increases, and when the proportion of (a2) decreases, (H) decreases.

The ratio of the absorption capacity (K) of the thickener for alkaline batteries of the present invention to 40 wt% potassium hydroxide aqueous solution and the absorption capacity (H) to ion-exchanged water can be determined from (K) / (H). .
In order to increase the absorption ratio {(K) / (H)}, the ratio of the non-hydrolyzable cross-linking agent (c12) in the cross-linking agent to be used is reduced, and the amount of metal ions contained in the thickener is increased. What is necessary is just to increase or reduce the ratio of (a2) contained in a polymer (A).
In order to lower the absorption ratio {(K) / (H)}, the proportion of the non-hydrolyzable crosslinking agent (c12) in the crosslinking agent to be used is increased, and the metal ion (b) contained in the thickening agent Or the proportion of (a2) contained in the polymer (A) may be increased.

Hereinafter, it describes about the manufacturing method of the thickener for alkaline batteries of this invention.
The thickener of this invention is good also considering the polymer (A) created by the manufacturing method of the above-mentioned polymer (A) as a thickener as it is. The polymer (A) is preferably dried rather than used as a hydrogel.

The drying temperature of the hydrogel varies depending on the dryer used and the drying time, but is preferably 50 to 150 ° C., more preferably 80 to 130 ° C. from the viewpoint of efficient drying and suppression of thermal crosslinking of the polymer.
The drying time of the hydrogel varies depending on the model of the dryer to be used, the drying temperature, and the like, but is preferably 5 to 300 minutes, more preferably 5 to 120 minutes from the viewpoint of reducing the water content and from an industrial viewpoint.

The thickener of the present invention may contain a hydroxide (D1) and / or a salt (D2) of the metal ion (b). When (D1) and / or (D2) is included, the polymer (A) may be mixed in the monomer during production, may be mixed in the hydrogel of the polymer (A), and (A) is dried. It may be mixed later, or (A) may be mixed after pulverization.
From the viewpoint of uniformly presenting (D1) and / or (D2) in the thickener, it may be mixed in the monomer during production of the polymer (A) or mixed with the hydrogel of the polymer (A). preferable.

Although it does not specifically limit as a shape of a thickener, From a viewpoint of the injectability to a storage can, it is preferable that it is a powder.
Examples of the shape of the powder include an irregularly crushed shape, a flake shape, a pearl shape, and a rice grain shape. From the viewpoint of injectability into a storage can, an irregularly crushed shape and a pearl shape are preferable, and an amorphous shape is more preferable. It is crushed.

  If necessary, the thickener is pulverized and powdered. The pulverization method may be a normal method, and can be performed by, for example, an impact pulverizer (pin mill, cutter mill, skiller mill, ACM pulverizer, etc.) or an air pulverizer (jet pulverizer, etc.).

As the powdered dried product, a dry powder having a desired particle diameter can be collected using a sieve (vibrating sieve, centrifugal sieve, etc.) equipped with a desired screen if necessary.
In addition, in this invention, it is preferable to remove metal powders, such as iron, mixed using the iron removing machine using magnetism in the arbitrary steps after drying. However, even if iron removal is performed with high precision, it is difficult to remove metals that are not magnetic with iron removal machines, and magnetic metals are also contained inside dry polymer particles. It is desirable to give sufficient consideration to the production equipment so that these metals are not mixed from the beginning, since it cannot be removed.

  When the thickener is a powder, the particle size is not particularly limited, but the weight average particle size of the dried product is 0.01 to 500 μm from the viewpoint of pouring into a storage can and retention of alkaline electrolyte. Is more preferable, and 0.1 to 200 μm is more preferable.

[Alkaline battery negative electrode composition]
The alkaline battery negative electrode composition of the present invention is a composition comprising an alkaline electrolyte, zinc powder and / or zinc alloy powder, and the thickener.

The alkaline electrolyte is an aqueous solution of metal hydroxide. Examples of the metal hydroxide include alkali metal (lithium, potassium, sodium, etc.) hydroxide, alkaline earth metal (calcium, magnesium, etc.) hydroxide, and mixtures thereof. Among these, a potassium hydroxide aqueous solution is preferable from the viewpoint of discharge characteristics of the alkaline battery.
In addition to the above metal hydroxide, the alkaline electrolyte may contain a metal oxide as required for the purpose of improving the discharge characteristics and productivity of the alkaline battery.
Examples of the metal oxide include alkali metal (lithium, potassium, sodium, etc.) oxide, alkaline earth metal (calcium, magnesium, etc.) oxide, and mixtures thereof. Of these, alkali metal oxides are preferred from the viewpoint of discharge characteristics of alkaline batteries.

  The metal hydroxide concentration (% by weight) in the alkaline electrolyte is preferably 20 to 50%, more preferably 25 to 45%, and particularly preferably 30 to 40% from the viewpoint of discharge characteristics of the alkaline battery.

  As the zinc powder, the shape of zinc is not particularly limited. The volume average particle diameter of the zinc powder is preferably from 0.1 to 2,000 μm, more preferably from 1 to 1,000 μm, particularly preferably from the viewpoint of uniform dispersibility in the alkaline electrolyte and filling into the negative electrode container described later. Is 10 to 500 μm.

Metals other than zinc contained in the zinc alloy powder are not particularly limited, but indium, bismuth and aluminum are preferable from the viewpoint of discharge characteristics of the alkaline battery.
The shape of the zinc alloy powder is not particularly limited, and the volume average particle diameter and its preferred range are the same as in the case of the zinc powder.

The alkaline battery negative electrode composition of the present invention is used in combination with other additives as necessary within the range of not impairing the effects of the present invention, for the purpose of improving the fluidity at the time of filling the negative electrode composition into the negative electrode container described later. can do.
Examples of other additives include gelling agents other than (A), vibration impact resistance improvers, discharge characteristic improvers, and the like.

  Examples of gelling agents other than (A) include carboxymethylcellulose (CMC), natural gums (such as guar gum), non-crosslinked poly (meth) acrylic acid (salt), and microcrosslinked poly (meth) acrylic acid ( Salt), cross-linked poly (meth) acrylic acid (salt), water-soluble resins such as polyvinyl alcohol, and the like. Among these, finely powdered micro-crosslinked poly (meth) acrylic acid (salt) and the like are preferable from the viewpoint of moderate injectability (fluidity) of the negative electrode composition into the negative electrode container.

  The weight average particle size (μm) of these gelling agents is to prevent sedimentation of zinc powder and / or zinc alloy powder (hereinafter sometimes abbreviated as zinc powder) and to fill the negative electrode container with the negative electrode composition. From this viewpoint, it is preferably 0.01 to 1,000, more preferably 0.1 to 850, and particularly preferably 0.5 to 500.

  The addition amount of the gelling agent excluding (A) is preferably 5% by weight or less based on the weight of the alkaline electrolyte from the viewpoints of filling properties of the composition into the negative electrode container and retention of the alkaline electrolyte. More preferably, the content is 0.01 to 3% by weight.

As another method for adding the gelling agent, the thickener of the present invention and the other gelling agent are previously dry blended and then mixed with other negative electrode composition components such as an alkaline electrolyte; the present invention. A method of adding and mixing another gelling agent separately from the preparation of the negative electrode composition containing the above thickener; after mixing the alkaline electrolyte and the other gelling agent, the thickener and zinc powder of the present invention And / or a method of adding and mixing zinc alloy powder.
Among these, from the viewpoint of uniform dispersibility, a method in which the thickener of the present invention and other gelling agent are dry-blended in advance and then mixed with other negative electrode composition components such as an alkaline electrolyte. is there.

Examples of the vibration impact resistance improver include metal oxides, hydroxides and sulfides selected from the group consisting of titanium, indium, tin and bismuth.
By adding the vibration impact resistance improver, it is possible to prevent the zinc electrolyte from being precipitated and the alkaline electrolyte from being liberated at the negative electrode when an impact is applied to the alkaline battery.
The addition amount of the vibration and impact resistance improver is preferably 5% by weight or less, more preferably 3.0% by weight or less, from the viewpoint of retention of the alkaline electrolyte, based on the weight of the alkaline electrolyte.

Examples of the discharge characteristic improver include known compounds having characteristics for preventing needle-like crystallization of zinc, such as silicon dioxide and potassium silicate.
The addition amount of the discharge characteristic improver is preferably 5% by weight or less, more preferably 3% by weight or less with respect to the alkaline electrolyte from the viewpoint of retention of the alkaline electrolyte.

The content of the alkaline electrolyte based on the total weight of the alkaline battery negative electrode composition is preferably 10 to 99% by weight, more preferably 20 to 97% by weight, from the viewpoint of the discharge characteristics of the alkaline battery and the retention of the alkaline electrolyte. .
The content of the thickener based on the total weight of the alkaline battery negative electrode composition is preferably 0.05 to 9% by weight, more preferably 0.2 to 3% from the viewpoints of discharge characteristics of the alkaline battery and retention of the alkaline electrolyte. .5% by weight.
The content of zinc powder and / or zinc alloy powder based on the total weight of the alkaline battery negative electrode composition is preferably from 0.3 to 89% by weight, more preferably from the viewpoint of discharge characteristics of the alkaline battery and retention of the alkaline electrolyte. 2 to 79% by weight.
The total of other additives based on the total weight of the alkaline battery negative electrode composition is preferably 10% by weight or less from the viewpoint of the discharge characteristics of the alkaline battery and the retention of the alkaline electrolyte.

  The manufacturing method using a well-known thickener can be used for the manufacturing method of the alkaline battery negative electrode composition of this invention.

[Alkaline battery]
In the alkaline battery of the present invention, a negative electrode formed by filling the negative electrode composition in a negative electrode container, a positive electrode agent, a separator separating the negative electrode and the positive electrode agent, and a current collecting rod are enclosed in a can.
The manufacturing method using the well-known alkaline negative electrode composition can be used for the manufacturing method of the alkaline battery of this invention.
The alkaline battery is not particularly limited, and examples include ordinary alkaline batteries such as LR-20 type (single 1 type alkaline battery) and LR-6 type (AA type alkaline battery) as well as various other alkaline batteries. .

  The negative electrode in the present invention is usually prepared by uniformly mixing the thickener of the present invention, an alkaline electrolyte, zinc powder and / or zinc alloy powder, and, if necessary, other additives in advance. It is manufactured by a method in which a product is filled in a negative electrode container of a battery to make a negative electrode.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to these. Hereinafter, unless otherwise specified, parts are parts by weight,% is weight%, ultrapure water is water having an electric conductivity of 0.06 μS / cm or less, and ion-exchanged water is water having an electric conductivity of 1.0 μS / cm or less. .

Example 1
Stir and mix 250 parts of acrylic acid, 0.25 parts of PE triallyl ether (0.1% acrylic acid), 0.75 parts of TMP triacrylate (0.3% acrylic acid) and 750 parts of ion-exchanged water. An aqueous acrylic acid solution was prepared and the temperature was adjusted to 4 ° C.
The aqueous acrylic acid solution was charged into an adiabatic polymerization tank, and the dissolved oxygen content in the aqueous acrylic acid solution was adjusted to 0.1 ppm or less through nitrogen in the aqueous solution. To this heat insulation polymerization layer, 1.25 parts of 10% 2,2′-azobis (2-amidinopropane) hydrochloride [trade name “V-50”, manufactured by Wako Pure Chemical Industries, Ltd.] aqueous solution was added. . 5 parts of 1% hydrogen peroxide solution and 5 parts of 0.1% L-ascorbic acid aqueous solution were added, and nitrogen bubbling into the aqueous solution was continued until polymerization started. After confirming that the polymerization was started and the viscosity of the aqueous acrylic acid solution started to rise, the nitrogen aeration was stopped and the polymerization was continued for 6 hours to obtain a hydrous gel comprising the polymer (A′-1). The maximum temperature reached in the reaction system was 75 ° C.
The block-shaped crosslinked hydrous gel composed of (A′-1) is taken out from the adiabatic polymerization tank, and the gel is 3 to 10 mm thick using a small meat chopper [model number “VR-400K”, manufactured by Royal Corporation]. After subdividing into noodles, 10 parts of magnesium hydroxide (special reagent grade) (equivalent to 10 mol% of acrylic acid neutralization) is added, and the water-containing gel is neutralized by passing through a mincing machine. A polymer (A-1) was obtained.
The polymer (A-1) is laminated on a SUS screen having an aperture of 850 μm with a thickness of 5 cm, and a small air-permeable dryer [model number “HAP2031F”, manufactured by HAKKO Corporation] is used. The hydrogel was dried by passing hot air at 120 ° C. through the hydrogel for 1 hour.
The dried product is pulverized using a cooking mixer, and a sieve having a particle size of 32 to 500 μm (400 to 30 mesh) is collected using a sieve, and a thickener having a weight average particle size (measured by Microtrac) of 150 μm. (1) was obtained.

The molar ratio (Q) in Example 1 was calculated from the following mathematical formula.
Molar ratio (Q) = (T × U) / S
S: Number of moles of acrylic acid used for production of polymer (A) T: Number of moles of magnesium hydroxide used for neutralization of acrylic acid U: 2 ionic valence of magnesium ion
The molar ratio (R) was calculated from the following formula.
Molar ratio (R) = (O × P) / S
S: Number of moles of acrylic acid used for production of polymer (A) O: Number of moles of magnesium hydroxide used for production of thickener P: 2 ionic valence of magnesium ion

Example 2
In Example 1, 0.25 part of PE triallyl ether was changed to 0.13 part (0.05% acrylic acid), 0.75 part of TMP triacrylate was not used, 10 parts of magnesium hydroxide 2 parts (corresponding to a neutralization degree of acrylic acid of 2 mol%), and the dried product was pulverized using an impact pulverizer (model number “Retch ZM200”, manufactured by Nippon Seiki Seisakusho Co., Ltd.). "Microtrack MT3000II" [trade name, manufactured by Nikkiso Co., Ltd. same as below. ] A thickener (2) was obtained in the same manner as in Example 1 except that the weight average particle diameter was 30 μm.
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Example 3
In Example 1, except that 0.75 part of TMP triacrylate was changed to 4.75 parts, and 10 parts of magnesium hydroxide was changed to 64 parts of aluminum hydroxide (corresponding to a neutralization degree of 71% by mole of acrylic acid). In the same manner as in No. 1, a thickener (3) having a weight average particle diameter of 150 μm was obtained.
The molar ratio (Q) in Example 3 was calculated from the following mathematical formula.
Molar ratio (Q) = (T × U) / S
S: Number of moles of acrylic acid used for production of polymer (A) T: Number of moles of aluminum hydroxide used for neutralization of acrylic acid U: Ion valence of aluminum ion 3
The molar ratio (R) was calculated from the following formula.
Molar ratio (R) = (O × P) / S
S: number of moles of acrylic acid used for production of polymer (A) O: number of moles of aluminum hydroxide used for production of thickener P: ionic valence of aluminum ion 3

Example 4
In Example 1, 0.75 part of TMP triacrylate was neutralized with 0.5 part of the same and 10 parts of magnesium hydroxide (corresponding to a neutralization degree of acrylic acid of 10 mol%), and then 122 parts of 40% aqueous sodium hydroxide solution ( A thickener (4) having a weight average particle diameter of 150 μm was obtained in the same manner as in Example 1 except that neutralization was performed with an acrylic acid neutralization degree of 35 mol%.
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Example 5
In Example 1, 0.25 part of PE triallyl ether (0.1% acrylic acid) was not used, 0.75 part of TMP triacrylate (0.3% acrylic acid) was 1.25 parts of the same. The weight average was obtained in the same manner as in Example 1 except that 10 parts by weight of magnesium hydroxide was changed to 101 parts (corresponding to a neutralization degree of acrylic acid of 100 mol%). A thickener (5) having a particle size of 150 μm was obtained.
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Example 6
In Example 1, 0.25 part of PE triallyl ether was added to 0.25 part of TMP diallyl ether (0.1% acrylic acid), and 0.75 part of TMP triacrylate was added to 0.75 part of N, N′-methylenebisacrylamide. A thickener (6) having a weight average particle size of 150 μm was obtained in the same manner as in Example 1 except that the content was 0.3 parts (0.3% acrylic acid).
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Example 7
To 242.3 parts of 25% aqueous sodium hydroxide solution (equivalent to 75 mol% acrylic acid neutralization), 0.05 parts magnesium hydroxide (equivalent to 0.08 mol% acrylic acid neutralization) was added and mixed uniformly. (Mixed solution 1). 9.4 parts of water was added to 145.4 parts of acrylic acid, and 242.3 parts of the mixed solution 1 was added while cooling to 20 to 30 ° C. to neutralize. EG diglycidyl ether [trade name “Denacol EX-810”, manufactured by Nagase Kasei Kogyo Co., Ltd.] 0.09 part, sodium hypophosphite monohydrate 0.0146 part, potassium persulfate 0.29 Part was added and uniformly dissolved to obtain an aqueous monomer solution. Subsequently, 624 parts of cyclohexane was charged into the reaction vessel, and further 2 parts of sorbitan monostearate was added and dissolved, and then the inside of the reaction vessel was purged with nitrogen while stirring. Next, after adjusting the temperature in the reaction vessel to 70 ° C., 397 parts of the monomer aqueous solution was dropped at a rate of 6.6 parts / minute over 1 hour, and then reacted and aged at 75 ° C. for 30 minutes. A suspension of polymer (A-7) was obtained.
Water and cyclohexane were removed azeotropically from the obtained suspension (A-7), and the water content was about 20% by weight [infrared moisture meter “FD-100 type”, manufactured by Kett Co., Ltd., heating temperature 180 Measured at 20 ° C. for 20 minutes]. The mixture was cooled to 30 ° C. and stirring was stopped to settle the resin particles. The resin particles were separated by decantation and dried to obtain a thickener (7). The weight average particle diameter of the thickener (7) was 300 μm.
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Example 8
150 parts of acrylic acid, 0.15 parts of PE triallyl ether (0.1% of acrylic acid), 0.45 parts of TMP triacrylate (0.3% of acrylic acid) and 850 parts of ion-exchanged water were mixed with stirring. An aqueous acrylic acid solution was prepared and the temperature was adjusted to 4 ° C.
The aqueous acrylic acid solution was charged into an adiabatic polymerization tank, and the dissolved oxygen amount in the aqueous acrylic acid solution was adjusted to 0.1 ppm or less by passing nitrogen through the aqueous solution. 0.75 part of 10% 2,2′-azobis (2-amidinopropane) hydrochloride [trade name “V-50”, manufactured by Wako Pure Chemical Industries, Ltd.] 3 parts of 1% hydrogen peroxide solution and 3 parts of 0.1% L-ascorbic acid aqueous solution were added, and nitrogen aeration into the aqueous solution was continued until polymerization started. After confirming that the polymerization started and the viscosity of the acrylic acid aqueous solution started to rise, the nitrogen aeration was stopped and the polymerization was continued for 6 hours to obtain a water-containing gel composed of the polymer (A′-8). The maximum temperature reached in the reaction system was 40 ° C.
The block-shaped crosslinked hydrous gel composed of (A′-8) is taken out from the adiabatic polymerization tank, and the gel is 3 to 10 mm thick using a small meat chopper [model number “VR-400K”, manufactured by Royal Corporation]. After subdividing into noodles, 6 parts of magnesium hydroxide (special grade reagent) (equivalent to 10 mol% neutralization of acrylic acid) is added and the water-containing gel is neutralized by passing through a mincing machine. A polymer (A-8) was obtained.
The polymer (A-8) is laminated on a SUS screen having an opening of 850 μm with a thickness of 5 cm, and a small air-permeable dryer [model number “HAP2031F”, manufactured by HAKKO Corporation] is used. The hydrogel was dried by passing hot air at 120 ° C. through the hydrogel for 1 hour.
The dried product was pulverized using a cooking mixer, and a sieve having a particle size of 32 to 500 μm (400 to 30 mesh) was collected using a sieve to obtain a thickener (8) having a weight average particle size of 150 μm.
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Example 9
Other than 0.15 parts of PE triallyl ether 0.15 parts of TMP diallyl ether (0.1% acrylic acid) and 12 parts of magnesium hydroxide (equivalent to 20 mol% neutralization of acrylic acid) Obtained a thickener (9) having a weight average particle diameter of 150 μm in the same manner as in Example 8.
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Example 10
A thickener (10) having a weight average particle diameter of 150 μm was obtained in the same manner as in Example 1 except that 250 parts of acrylic acid was changed to 225 parts of acrylic acid and 25 parts of methyl acrylate.
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Example 11
In Example 1, 10 parts of magnesium hydroxide was 121 parts (corresponding to a neutralization degree of acrylic acid of 120 mol%), and 0.25 parts of PE triallyl ether (0.1% of acrylic acid) was not used. Except that, a thickener (11) having a weight average particle diameter of 150 μm was obtained in the same manner as in Example 1.
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Example 12
100 parts acrylic acid, 0.10 parts PE triallyl ether (0.1% acrylic acid), 0.30 parts TMP triacrylate (0.3% acrylic acid) and 900 parts ion-exchanged water were mixed with stirring. An aqueous acrylic acid solution was prepared and the temperature was adjusted to 4 ° C.
The aqueous acrylic acid solution was charged into an adiabatic polymerization tank, and the dissolved oxygen amount in the aqueous acrylic acid solution was adjusted to 0.1 ppm or less by passing nitrogen through the aqueous solution. To this heat insulation polymerization layer, 0.50 part of 10% 2,2′-azobis (2-amidinopropane) hydrochloride [trade name “V-50”, manufactured by Wako Pure Chemical Industries, Ltd.] aqueous solution was added, 0 2 parts of 1% hydrogen peroxide solution and 2 parts of 0.1% L-ascorbic acid aqueous solution were added, and nitrogen bubbling into the aqueous solution was continued until polymerization started. After confirming that the polymerization had started and the viscosity of the aqueous acrylic acid solution started to rise, the nitrogen aeration was stopped and the polymerization was carried out for 6 hours to obtain a water-containing gel comprising the polymer (A′-12). The maximum temperature reached in the reaction system was 40 ° C.
A block-like crosslinked hydrous gel composed of (A′-12) is taken out from the adiabatic polymerization tank, and the gel is 3 to 10 mm thick using a small meat chopper [model number “VR-400K”, manufactured by Royal Corporation]. After subdividing into noodles, add 4 parts of magnesium hydroxide (special grade reagent) (equivalent to 10 mol% neutralization of acrylic acid) and pass through a mincing machine to neutralize the hydrated gel. A polymer (A-12) was obtained.
The polymer (A-12) is laminated on a SUS screen having an aperture of 850 μm with a thickness of 5 cm, and a small air-permeable dryer [model number “HAP2031F”, manufactured by HAKKO Corporation] is used. The hydrogel was dried by allowing hot air of 120 ° C. to pass through the hydrogel for 2 hours.
The dried product was pulverized using a cooking mixer, and a sieve having a particle size of 32 to 500 μm (400 to 30 mesh) was collected using a sieve to obtain a thickener (12) having a weight average particle size of 300 μm.
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Comparative Example 1
Commercially available carboxymethyl cellulose [trade name “CMC2450”, manufactured by Daicel Chemical Industries, Ltd.] was used as the thickener (H1).

Comparative Example 2
In Example 1, except that PE triallyl ether was not used, and 10 parts of magnesium hydroxide was replaced with 347.2 parts of sodium hydroxide 40% aqueous solution (equivalent to neutralization degree of acrylic acid of 100 mol%). In the same manner as in Example 1, a thickener (H2) was obtained.

Comparative Example 3
In Example 1, a thickener (H3) was obtained in the same manner as in Example 1 except that PE triallyl ether and TMP triacrylate were not used and magnesium hydroxide was not added.

Comparative Example 4
In Example 1, 0.25 part of PE triallyl ether was changed to 7.5 parts (to 3.0% acrylic acid), 312.5 parts of 40% aqueous sodium hydroxide solution (degree of neutralization of acrylic acid 90) After neutralizing with a molar equivalent), a thickener (H4) was obtained in the same manner as in Example 1 except that 10 parts of magnesium hydroxide (equivalent to a neutralization degree of acrylic acid of 10 mol%) was added. .
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

Comparative Example 5
In Example 1, 10% 2,2′-azobis (2-amidinopropane) hydrochloride aqueous solution, 0.1% hydrogen peroxide solution, and 0.1% L-ascorbic acid aqueous solution were 10 times the amount of Example 1, respectively. A thickener (H5) was obtained in the same manner as in Example 1 except that 750 parts of 20% aqueous ethanol solution (ethanol / water = 20/80) was used instead of 750 parts of ion-exchanged water. It was.
In the same manner as in Example 1, the molar ratio (Q) and molar ratio (R) were calculated.

  The following items were evaluated for the thickeners (1) to (12) and the thickeners (H1) to (H5). The results are shown in Table 2.

(1) Variation in injection time and injection amount A biaxial kneader with a capacity of 1 L was charged with 150 g of 35% aqueous potassium hydroxide, 300 g of zinc powder (the same as above), and 3.0 g of a thickener, at a rotation speed of 50 rpm. A negative electrode composition was prepared by mixing for 60 minutes. The composition was allowed to stand at 25 ° C. for 23 hours, mixed uniformly, then transferred to a beaker, and bubbles introduced during mixing were degassed under reduced pressure. The resulting composition was aspirated into a 20 ml syringe with an inlet diameter of 2 mm and a scale of 0.1 ml.
From the height of the opening of a glass container (inner diameter: 18 mm, height: 40 mm) having a capacity of 5 ml, the composition in the syringe is extruded by 2.0 ml and injected into the glass container, at which time the extrusion from the syringe is finished The time (seconds) from when the composition was completely removed from the syringe inlet was measured with a stopwatch. An average value of 20 times in total in which similar operations were repeated was taken as the injection time (seconds). The weight (20 times each) of the negative electrode composition injected into the glass container was measured, and the standard deviation (σ) of the injection amount was calculated to determine the variation in the injection amount.

(2) Alkaline electrolyte retention (separation rate)
In addition, said alkaline electrolyte solution retainability is evaluated by the separation rate measured by the following method.
<Method of measuring the separation rate>
100 parts of 35% potassium hydroxide aqueous solution, 2 parts of thickener, and 200 parts of zinc powder having a weight average particle diameter of 10 to 400 μm were stirred and mixed until uniform. 75 parts of this sample was taken and allowed to stand at 25 ° C. for 24 hours. Placed in the bottom of a tea bag made of a nylon screen having a mesh opening of 32 μm (400 mesh) prepared according to JIS K7223-1996, the tea bag was suspended with a clip and allowed to stand for 30 minutes. Then, the weight (w1) (part) after draining the tea bag is measured. Further, the weight (w2) (part) of the tea bag itself is measured, and the separation rate is calculated by the following equation.

Separation rate (%) = [75− (w1) + (w2)] × 100/75

(3) Precipitation of zinc powder A biaxial kneader having a capacity of 1 L [model number “PNV-1”, manufactured by Irie Shokai Co., Ltd., and the same applies hereinafter. ] Zinc powder [trade name “004F (2) / 68”, UNION MINIERES. A. Co., Ltd.] 300 parts and 3 parts of a thickener were charged and mixed at a rotational speed of 50 rpm for 60 minutes to prepare a negative electrode composition. 50 parts of the negative electrode composition was placed in a sealable 50 ml transparent container (diameter 34 mm, height 77 mm, made of polypropylene), and bubbles mixed during mixing were degassed under reduced pressure.
The container was sealed and allowed to stand in a constant temperature bath at 40 ° C. for 30 days, and then the container was removed 30 times from a height of 3 cm using an apparatus attached to “Powder Tester” [trade name, manufactured by Hosokawa Micron Corporation]. Tapping 300 times at a rate of / min promoted the precipitation of zinc powder. After the end of tapping, the distance (mm) from the initial position of the zinc powder (the position of the upper end of the negative electrode composition in the container) to the top of the precipitated zinc powder was measured, and this was determined as the precipitation of the zinc powder. (Mm).

(4) Discharge characteristics (battery discharge duration)
A biaxial kneader with a capacity of 1 L is charged with 150 parts of a 35% aqueous potassium hydroxide solution, 300 parts of zinc powder (same as above) and 3 parts of a thickener, and mixed at 50 rpm for 60 minutes to prepare a negative electrode composition. Created. After defoaming the composition under reduced pressure, 15 parts of the negative electrode composition was poured into a negative electrode container of an LR-6 model battery to form a negative electrode, thereby preparing a model battery.
Here, as the constituent material of each part other than the negative electrode of the model battery, the material of the shrinkable tube is polyethylene, the positive electrode agent is 50 parts of electrolytic manganese dioxide, 5 parts of acetylene black, and a 40% strength aqueous potassium hydroxide solution 1 As the material of the can, the container can be nickel-plated steel sheet, the separator is polyolefin, the current collector is tin-plated brass, the gasket is polyolefin resin, negative electrode A nickel-plated steel plate was used as the material for the terminal plate.
An external resistance of 2Ω was connected to the created model battery at room temperature (20 to 25 ° C.) and continuously discharged, and the time until the voltage decreased to 0.9 V was defined as the battery duration (hr). After the model battery was created, the same operation was performed on the model battery that was left in a constant temperature bath at 60 ° C. for 60 days, and the battery duration (hr) was measured.

(5) Vibration and shock resistance of the battery The model battery made from the height of 1 m was connected to the model battery made in the same manner as described above and connected to an external resistor of 2Ω at room temperature (20-25 ° C) for continuous discharge. It was allowed to naturally drop 10 times on the plate, the voltage (Va) before the first drop and the voltage (Vb) immediately after the 10th drop were measured, and the vibration impact resistance (%) was calculated by the following formula. .

Vibration impact resistance (%) = 100 × (Vb) / (Va)

(6) Spinnability A biaxial kneader with a capacity of 1 L is charged with 150 parts of 35% aqueous potassium hydroxide solution, 300 parts of zinc powder (same as above) and 3 parts of thickener, and mixed for 60 minutes at a rotation speed of 50 rpm. Then, a negative electrode composition was prepared. The negative electrode composition was allowed to stand at 25 ° C. for 23 hours, and then uniformly stirred with a polytetrafluoroethylene stirring rod (length 30 cm, diameter 1 cm), and then the stirring rod was gradually pulled up vertically. The spinnability was visually observed and evaluated according to the following criteria.
<Evaluation criteria>
◎ 10mm or less ○ Over 10mm, 20mm or less △ Over 20mm, 30mm or less × Greater than 30mm

From the results of Table 1, the thickeners [(1) to (12)] of the present invention satisfy the requirements (1) and (2) in the present invention, and the comparative thickeners [(H1) to (H5). )] Does not satisfy at least one of the requirements (1) and (2).
Moreover, from the results of Table 2, in the evaluation results of the spinnability, the evaluation results of the negative electrode composition using the thickener of the present invention are those of the negative electrode composition using the thickener of Comparative Examples 1 to 5. It is equal to or better than the evaluation result, and it can be seen that it is excellent. In addition, with regard to the evaluation results of injection time, variation in injection amount, alkaline electrolyte retention (separation rate), zinc powder sedimentation and vibration impact resistance of the battery, those using the thickener of the present invention, It can be seen that it is significantly better than the comparative example using the thickener.
Further, regarding the discharge characteristics of the battery, the discharge duration immediately after the preparation was longer in all the batteries using the thickener of the present invention than the battery using the thickener of the comparative example, and the thickener of the present invention. It can be seen that the battery using is excellent. Furthermore, the discharge duration after standing for 60 days in a constant temperature bath at 60 ° C. is longer in all the batteries using the thickener of the present invention than in the battery using the thickener of the comparative example. It turns out that the battery using this thickener is excellent.
Therefore, it turns out that the thickener of this invention is excellent in all the evaluation results.

  The thickener for an alkaline battery of the present invention provides a negative electrode composition that is excellent in pouring into a storage can (negative electrode container) and holding ability of an alkaline electrolyte. Moreover, the alkaline battery using the thickener of the present invention is excellent in long-term discharge characteristics and vibration shock resistance. Therefore, the thickener of the present invention can be widely used as a thickener for various alkaline batteries [LR-20 type (single type 1 alkaline battery), LR-6 type (single type alkaline battery), etc.]. Very useful.

Claims (10)

The following ethylenically unsaturated monomer (a1) and / or the following ethylenically unsaturated monomer (a2) and a polymer (A) having the following ethylenically unsaturated monomer (a3) as essential constituent units are contained, and the following requirements (1 ) And (2), a thickener for alkaline batteries.
Ethylenically unsaturated monomer (a1): An ethylenically unsaturated monomer having at least one anionic group selected from the group consisting of a carboxyl group, a sulfo group and a phosphate group.
Ethylenically unsaturated monomer (a2): a salt of (a1) and an alkali metal and / or onium cation.
Ethylenically unsaturated monomer (a3): a salt of (a1) and a divalent or higher valent metal ion (b).
Requirement (1): The molar ratio (Q) in (A) determined by the following mathematical formula (1) is 0.0008 to 0.99999 .
Molar ratio (Q) = Σ (Ta × Ua) / S (1)
[In Formula (1), S is the total number of moles of anion groups and anion bases of (a1), (a2) and (a3), Ta is the number of moles of each metal ion (b) in (A), and Ua is It represents the ionic valence of each metal ion (b). ]
Requirement (2): The viscosity at 25 ° C. of the mixed solution after the thickener for alkaline battery and the 40 wt% potassium hydroxide aqueous solution are stirred and mixed at a weight ratio of 1/99 for 1 hour and left to stand at 40 ° C. for 24 hours ( V1) is 50 to 5,000 mPa · s.   The thickener according to claim 1, wherein the polymer (A) further comprises an internal crosslinking agent (c1) as an essential constituent unit.   The thickener according to claim 2, wherein the proportion of the internal crosslinking agent (c1) is 0.01 to 2% by weight based on the total weight of the ethylenically unsaturated monomers (a1), (a2) and (a3). .   The thickener according to any one of claims 1 to 3, wherein the polymer (A) further comprises another water-soluble ethylenically unsaturated monomer (a4) as an essential constituent unit.   The weight ratio [{(a1) + (a2) + (a3)} / (a4)] of the total weight of the ethylenically unsaturated monomers (a1), (a2) and (a3) to the weight of (a4) is: The thickener according to claim 4, which is 75/25 to 100/0.   Furthermore, the thickener in any one of Claims 1-5 containing the hydroxide (D1) and / or salt (D2) of a metal ion (b). The increase according to claim 6, wherein the molar ratio (R) between the metal ion (b) in the thickener and the anion group in the polymer (A) determined by the following formula (2) is 1 to 1.2. Sticky.
Molar ratio (R) = Σ (Oa × Pa) / S (2)
[In Formula (2), S is the total number of moles of anionic groups and anionic bases of (a1), (a2) and (a3) in (A), Oa is the number of each metal ion (b) in the thickener. The number of moles, Pa, represents the ionic valence of each metal ion (b). ]   The ratio [(K) / (H)] of the absorption capacity (K) of the thickener to the 40 wt% aqueous potassium hydroxide solution and the absorption capacity (H) of the thickener to the ion-exchanged water is 0.01 to 200. The thickener according to any one of claims 1 to 7.   An alkaline battery negative electrode composition comprising an alkaline electrolyte, zinc powder and / or zinc alloy powder, and the thickener according to claim 1. An alkaline battery in which a negative electrode formed by filling the negative electrode composition according to claim 9 into a negative electrode container, a positive electrode agent, a separator separating the negative electrode and the positive electrode agent, and a current collecting rod are enclosed in a storage can.