WO2020217782A1

WO2020217782A1 - Negative electrode addditive for alkaline battery, and alkaline battery

Info

Publication number: WO2020217782A1
Application number: PCT/JP2020/011677
Authority: WO
Inventors: 興滋加峰; 孝之中野; 亜耶竹村
Original assignee: 三洋化成工業株式会社
Priority date: 2019-04-25
Filing date: 2020-03-17
Publication date: 2020-10-29
Also published as: JP2022096002A

Abstract

Provided is a negative electrode additive for alkaline battery which has outstanding sedimentation prevention properties for zinc powder and the like in an alkali electrolyte, and which can exhibit performance in a single material. The negative electrode additive contains: a cross-linked polymer (A) which has, as essential constituent monomers, an aqueous vinyl monomer (a1) and/or a hydrolyzable vinyl monomer (a2) and a cross-linking agent (b). The negative electrode additive satisfies the following: (1) the amount of the component of the cross-linkable polymer (A) that can be dissolved in saline solution is 5-20 wt% with respect to the weight of (A); (2) the ratio (Mw/Mn) of Mw to Mn of the component having a molecular weight not exceeding 100,000, from within the component of (A) that can be dissolved in saline solution falls within the range of 4.0-6.0, and the ratio of the surface area of components having a molecular weight not exceeding 100,000 with respect to the total surface area of a GPC chromatogram does not exceed 50%; and (3) the viscosity at 25°C of a mixed solution obtained by adding 2 wt% of the negative electrode additive (G) for alkaline battery to a 40 wt% aqueous solution of potassium hydroxide is 10-60 Pa·s.

Description

Negative electrode additives for alkaline batteries and alkaline batteries

The present invention relates to an additive for the negative electrode of an alkaline battery and an alkaline battery. More specifically, the present invention relates to a negative electrode additive for primary and secondary alkaline batteries having a negative electrode material mainly composed of an alkaline electrolytic solution and zinc powder, and an alkaline battery using the same.

Conventionally, the negative electrode material of an alkaline battery has been a high-concentration alkaline electrolytic solution (containing a high-concentration potassium hydroxide aqueous solution and, if necessary, zinc oxide, etc.), zinc powder and / or zinc alloy powder (in the present specification). , Zinc powder, etc.) is used as the main component. Zinc powder or the like in the alkaline electrolytic solution tends to settle, and a gelling agent may be further used for the purpose of preventing this. As the gelling agent, the alkali metal salt powder of high degree of polymerization crosslinked polyacrylic acid can be used alone, or the alkali metal salt powder of high degree of polymerization crosslinked polyacrylic acid having a thickening effect and the alkali metal of carboxymethyl cellulose can be used. Those using a salt in combination have been proposed (for example, Patent Document 1). Further, a compound having a thickening action such as crosslinked poly (meth) acrylic acid having different particle diameters and salts thereof is mixed and used as a gelling agent (see, for example, Patent Document 2).

Japanese Patent No. 2775829 Japanese Patent No. 3371532

However, the gelling agents described in Patent Documents 1 and 2 do not have sufficient anti-sedimentation properties for zinc powder and the like in the alkaline electrolytic solution, and in terms of maintaining the discharge characteristics of the battery for a long period of time and impact resistance. It wasn't always satisfactory. In addition, there is a problem that it is necessary to mix a plurality of materials and the number of production processes increases.

The present invention has been made in view of these problems, and an object of the present invention is to have excellent sedimentation prevention properties such as zinc powder in an alkaline electrolytic solution, and to use one material without using a plurality of materials. It is an object of the present invention to provide an additive for a negative electrode of an alkaline battery capable of exhibiting performance.

The present invention contains a water-soluble vinyl monomer (a1) and / or a vinyl monomer (a2) that becomes (a1) by hydrolysis and a cross-linked polymer (A) containing a cross-linking agent (b) as an essential constituent monomer unit. An alkaline battery containing the negative electrode additive (G) of the alkaline battery satisfying the following (1) to (3), the negative electrode additive (G), zinc powder, and the like:
(1) The amount of the soluble component of the crosslinked polymer (A) in 0.9% by weight of physiological saline (hereinafter, also simply referred to as physiological saline) is 5 to 40% by weight based on the weight of (A). ;
(2) Among the soluble components of the crosslinked polymer (A) in physiological saline, all of them have a weight average molecular weight with respect to the number average molecular weight (Mn) of the components having a molecular weight of 100,000 or less, which are obtained by the method described later. The ratio (Mw / Mn) of (Mw) is 4.0 to 6.0, and the chromatography of the gel permeation chromatography method obtained for the soluble component of the crosslinked polymer (A) in physiological saline The ratio of the area of soluble components having a molecular weight of 100,000 or less to the total area of the gram is 50% or less;
(3) The viscosity of a mixed solution prepared by adding 2% by weight of the negative electrode additive (G) for an alkaline battery to a 40% by weight aqueous potassium hydroxide solution at 25 ° C. is 10 to 60 Pa · s.

The negative electrode additive (G) for the alkaline battery of the present invention and the alkaline battery using the additive (G) have the following effects.
(1) The negative electrode additive (G) for the alkaline battery of the present invention is excellent in preventing the precipitation of zinc powder and the like in the negative electrode material. Therefore, when used in an alkaline battery, it is possible to produce a battery having extremely excellent discharge duration and impact resistance over a long period of time with a small amount.
(2) Since the negative electrode additive (G) for the alkaline battery of the present invention can exhibit performance with one material without using a plurality of materials, the battery production process can be reduced as much as possible, and the production cost can be reduced. Excellent in terms of.
(3) The negative electrode material to which the negative electrode additive (G) for the alkaline battery of the present invention is added has an appropriate viscosity at the time of filling, and the negative electrode material is easily drained. Therefore, since there is little variation in the filling amount of the negative electrode material per battery, it is possible to produce a battery having uniform quality even during mass production. Further, even in a small battery, the negative electrode material can be filled uniformly and at high speed, so that a battery having uniform quality can be produced.

The negative electrode additive (G) of the alkaline battery of the present invention is also a water-soluble vinyl monomer (a1) and / or a vinyl monomer (a2) which becomes (a1) by hydrolysis (hereinafter, hydrolyzable vinyl monomer (a2)). ) And the cross-linking polymer (A) containing the cross-linking agent (b) as an essential constituent monomer.

In the present invention, the water-soluble vinyl monomer means a vinyl monomer having a property of dissolving at least 100 g in 100 g of water at 25 ° C.
The water-soluble vinyl monomer (a1) and / or the hydrolyzable vinyl monomer (a2) is not particularly limited, and examples thereof include the water-soluble radical polymerization monomer described in JP-A-2005-075982. Of these, from the viewpoint of discharge characteristics, the water-soluble vinyl monomer (a1) is preferable, more preferably an anionic vinyl monomer, and particularly preferably a vinyl group-containing carboxylic acid (salt) having 3 to 30 carbon atoms {unsaturated monocarboxylic acid). Acids (salts) [(meth) acrylic acid, crotonic acid, cinnamic acid and their salts, etc.]; unsaturated dicarboxylic acids (salts) (maleic acid, fumaric acid, citraconic acid, itaconic acid and their salts, etc.); and Monoalkyl (1 to 8 carbon atoms) ester of unsaturated dicarboxylic acid (maleic acid monobutyl ester, fumaric acid monobutyl ester, maleic acid ethylcarbitol monoester, fumaric acid ethylcarbitol monoester, citraconic acid mono Butyl esters, itaconic acid glycol monoesters, etc.}, especially unsaturated monocarboxylic acids (salts), most preferably acrylic acids (salts).

In the present invention, (meth) acrylic acid means acrylic acid and / or methacrylic acid, and "... acid (salt)" means "... acid" and / or "... acid acid". means. Examples of the salt include alkali metal salts such as potassium, sodium and lithium, and alkaline earth metal salts such as calcium.

The unit derived from the water-soluble vinyl monomer (a1) may be an unneutralized product or a neutralized product (unit of a water-soluble vinyl monomer salt). Further, it is preferable that the crosslinked polymer (A) is partially or completely neutralized from the viewpoint of reducing adhesiveness, improving dispersibility, and workability in producing the crosslinked polymer (A).

When neutralizing units derived from the water-soluble vinyl monomer (a1) contained in the crosslinked polymer (A), generally, alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and lithium hydroxide, and water are used. An alkaline earth metal hydroxide such as calcium oxide or an aqueous solution thereof may be added to the monomer stage before the polymerization or the hydrogel after the polymerization, but the alkaline and non-hydrolyzable cross-linking agent (b2) described later has poor water solubility. Therefore, when the water-soluble vinyl monomer (a1) is polymerized in a highly neutralized state, the cross-linking agent (b2) is separated from the monomer aqueous solution even if a predetermined amount of the cross-linking agent (b2) is added, and the predetermined cross-linking cannot be performed. The crosslinked polymer (A) may not be obtained, and the degree of neutralization of the water-soluble vinyl monomer (a1) is set to 0 to 30 mol%, and the crosslinking agent (b2) is also contained to carry out the polymerization. If necessary, it is more preferable to add an alkali metal hydroxide to the hydrogel to adjust the degree of neutralization.

When an anionic vinyl monomer {most preferably acrylic acid (salt)} is used as the water-soluble vinyl monomer (a1) of the crosslinked polymer (A), the final degree of neutralization of the anionic vinyl monomer {anionic vinyl The content of the anionic base (mol%)} based on the total number of moles of the anionic group and the anionic base of the monomer is preferably 0 to 90, more preferably 40 to 80, and particularly preferably 60 to 70. Within these ranges, the impact resistance and discharge characteristics of the negative electrode material are further improved. The anionic base means a neutralized anionic group.

The contents of the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2) are (a1), (a2) and alkaline and hydrolyzed from the viewpoint of the absorbability of the negative electrode additive (G) of the alkaline battery. 98.0 to 99.90% by weight is preferable, and 99.0 to 99.85% by weight is particularly preferable, based on the total weight of the cross-linking agent (b1) and the alkaline and non-hydrolyzing cross-linking agent (b2). It is preferably 99.2 to 99.83% by weight.

As the water-soluble vinyl monomer (a1) and / or the hydrolyzable vinyl monomer (a2), one type may be used alone or two or more types may be used in combination.

Of the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2), (a1) alone and (a1) and (a2) are preferably used alone or in combination with (a2) from the viewpoint of the discharge characteristics of the alkaline battery. a1) Alone.
When both the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2) are used as constituent units, the molar ratio of the units derived from these vinyl monomers {(a1) / (a2)} is the alkaline battery. From the viewpoint of discharge characteristics, it is preferably 75/25 to 99/1, more preferably 85/15 to 98/2, and most preferably 90/10 to 95/5.

In addition to the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2), the crosslinked polymer (A) can contain other vinyl monomer (a3) copolymerizable with these as a constituent unit. The other vinyl monomer (a3) may be used alone or in combination of two or more.

The other copolymerizable vinyl monomer (a3) is not particularly limited, and the hydrophobic vinyl monomer disclosed in paragraphs [0028] to [0029] of Japanese Patent No. 36485553, JP-A-2003- Hydrophobic vinyl monomers (such as the vinyl monomers disclosed in paragraph [0025] of Japanese Patent Application Laid-Open No. 165883 and paragraph [0058] of JP-A-2005-75982) can be used, and specifically, for example, (i) below. -(Iii) vinyl monomer and the like can be used.
(I) Aromatic ethylenic monomer having 8 to 30 carbon atoms Styrene such as styrene, α-methylstyrene, vinyltoluene and hydroxystyrene, halogen-substituted styrene such as vinylnaphthalene and dichlorostyrene and the like.
(Ii) Alkenes (ethylene, propylene, butene, isobutylene, pentene, heptene, diisobutylene, octene, dodecene, octadecene, etc.); and alkaziene (butadiene and isoprene, etc.) having 2 to 20 carbon atoms.
(Iii) Alicyclic ethylenic monomer having 5 to 15 carbon atoms Monoethylene unsaturated monomer (pinene, limonene, inden, etc.); and polyethylene vinyl monomer [cyclopentadiene, bicyclopentadiene, ethylidene norbornene, etc.] and the like.

The content (mol%) of the other vinyl monomer (a3) unit in the copolymer (A) is the water-soluble vinyl monomer (a1) unit and the hydrolyzable vinyl monomer (a2) unit from the viewpoint of absorption performance and the like. Based on the total number of moles, 0 to 5 mol% is preferable, more preferably 0 to 3 mol%, particularly preferably 0 to 2 mol%, particularly preferably 0 to 1.5 mol%, and the absorption performance and the like. From the viewpoint, the content of the other vinyl monomer (a3) unit is most preferably 0 mol%.

The crosslinked polymer (A) is made into a crosslinked product by using a crosslinking agent (b). Examples of the cross-linking agent (b) include a cross-linking agent (b1) that is alkaline and hydrolyzes, and a cross-linking agent (b2) that is alkaline and does not hydrolyze.
In the present invention, it is preferable to use (b1) and (b2) together. By using (b1) and (b2) together, the viscosity stability of the negative electrode additive (G) of the alkaline battery can be further improved, and the separation of the alkaline electrolytic solution can be prevented, so that the battery can be used for a long period of time. It is possible to maintain the discharge over. Further, it is preferable because it can be uniformly injected when filling the battery and the bias in the injection amount of the electrolytic solution per battery is small.
Here, the term "leaving" of the alkaline electrolytic solution means that the negative electrode additive (G) of the alkaline battery and the alkaline electrolytic solution cannot be maintained in a substantially uniform mixed state, and the negative electrode additive (G) of the alkaline battery cannot be maintained. ) And the alkaline electrolytic solution are separated.

In the cross-linking agent (b1) that hydrolyzes alkaline, "hydrolyzing with alkalinity" means that the unit derived from (b1) in the cross-linked polymer (A) has a hydrolyzable bond, and is hydrolyzable. The bond may be a bond that the cross-linking agent (b1) originally has in the molecule {the cross-linking agent in this case is a cross-linking agent (b11) having a hydrolyzable bond in the molecule}, a cross-linked polymer. The bond formed by the cross-linking reaction with the other monomer {(a1) or (a2)} constituting (A) may be hydrolyzed {the cross-linking agent in this case is cross-linked. The bond formed is a hydrolyzable cross-linking agent (b12)}.
The hydrolyzable bond includes an ester bond, an amide bond and the like.

Examples of the cross-linking agent (b11) having a hydrolyzable bond in the molecule include N, N'-methylenebisacrylamide, ethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, and trimethylolpropane tri (). 2 to 10 ethylenic properties in molecules such as meta) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and polyglycerin (polymerization degree 3 to 13) polyacrylate. Examples thereof include copolymerizable cross-linking agents having an unsaturated bond.

Examples of the cross-linking agent (b12) in which the bond formed by the cross-linking reaction is hydrolyzable include a polyvalent glycidyl compound (ethylene glycol diglycidyl ether, etc.), a polyvalent isocyanate compound (4,4'-diphenylmethane diisocyanate, etc.), and a polyvalent Examples thereof include reactive cross-linking agents that react with carboxylic acids typified by amine compounds (ethylene diamine, etc.) and polyhydric alcohol compounds (glycerin, etc.). The reactive cross-linking agent can react with (meth) acrylic acid (salt) to form an ester bond or an amide bond.

Among the cross-linking agents (b1) that hydrolyze with alkali, polyvalent acrylamide compounds and polyvalent acrylate compounds are preferable, and more preferable, from the viewpoint of viscosity stability of the negative electrode material to which the negative electrode additive (G) for an alkaline battery is added. Of N, N'-methylenebisacrylamide, ethylene glycol di (meth) acrylate, trimethylolpropantri (meth) acrylate and pentaerythritol tri (meth) acrylate, more preferably N, N'-methylenebisacrylamide, Ethylene glycol di (meth) acrylates, trimethyl propantri (meth) acrylates and ethylene glycol diglycidyl ethers, most preferably N, N'-methylenebisacrylamide and trimethyl propantri (meth) acrylates.

The alkaline, non-hydrolyzable cross-linking agent (b2) is a cross-linking agent that does not have a hydrolyzable bond in the molecule and does not generate a hydrolyzable bond by a cross-linking reaction. Examples of such a cross-linking agent (b2) include a cross-linking agent having two or more vinyl ether bonds (b21) and a cross-linking agent having two or more allyl ether bonds (b22). Preferably, it is a cross-linking agent having two or more allyl ether bonds from the viewpoint of reactivity and the like.

Examples of the cross-linking agent (b21) having two or more vinyl ether bonds include ethylene glycol divinyl ether, 1,4-butanediol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, 1,6-hexanediol divinyl ether, and polyethylene. Examples thereof include glycol divinyl ether (polymerization degree 2 to 5), bisphenol A divinyl ether, pentaerythritol trivinyl ether, sorbitol trivinyl ether and polyglycerin (polymerization degree 3 to 13) polyvinyl ether.

Examples of the cross-linking agent (b22) having two or more allyl ether bonds include a cross-linking agent (b221) having two allyl groups in the molecule and containing no hydroxyl group, and a cross-linking agent (b221) having two allyl groups in the molecule and having a hydroxyl group. A cross-linking agent (b222) having 1 to 5 allyl groups, a cross-linking agent (b223) having 3 to 10 allyl groups in the molecule and no hydroxyl group, and a cross-linking agent having 3 to 10 allyl groups in the molecule and having a hydroxyl group. Examples thereof include a cross-linking agent (b224) having 1 to 3 of. When a hydroxyl group is contained in the molecule, the compatibility with the vinyl monomer (a1) and / or (a2) {particularly (meth) acrylic acid (salt)} is good, the uniformity of cross-linking is increased, and the addition to the negative electrode of an alkaline battery is performed. The performance of the agent (G) is improved, and the long-term stability of the viscosity of the negative electrode material containing the negative electrode additive (G) for the alkaline battery is further excellent.

Examples of the cross-linking agent (b221) having two allyl groups in the molecule and containing no hydroxyl group include 1,4-cyclohexanedimethanol diallyl ether, alkylene (2 to 5 carbon atoms) glycol diallyl ether, and polyalkylene (carbon number). 2 to 6) Glycol (weight average molecular weight: 100 to 4000) diallyl ether and the like can be mentioned.
Examples of the cross-linking agent (b222) having two allyl groups and 1 to 5 hydroxyl groups in the molecule include glycerin diallyl ether, trimethylolpropane diallyl ether, pentaerythritol diallyl ether, and polyglycerin (degree of polymerization 2 to 5). Examples thereof include diallyl ether and the like.
Examples of the cross-linking agent (b223) having 3 to 10 allyl groups in the molecule and no hydroxyl group include trimethylolpropane triallyl ether, glycerin triallyl ether, pentaerythritol tetraallyl ether, and tetraallyloxyethane. Can be mentioned.
Examples of the cross-linking agent (b224) having 3 to 10 allyl groups and 1 to 3 hydroxyl groups in the molecule include pentaerythritol triallyl ether, diglycerin triallyl ether, sorbitol triallyl ether, and polyglycerin (degree of polymerization). 3 to 13) Polyallyl ether and the like can be mentioned.

Two or more kinds of cross-linking agents (b2) that are alkaline and do not hydrolyze may be used in combination.
Among the cross-linking agents (b2), the cross-linking agent (b22) having two or more allyl ether bonds is preferable, and more preferably, the cross-linking agent {(b222) and (b222) having 1 to 5 hydroxyl groups and 2 to 10 allyl groups. b224)}, particularly preferably a cross-linking agent (b224) having 3 to 10 allyl groups and 1 to 3 hydroxyl groups in the molecule, most preferably pentaerythritol triallyl ether, diglycerin triallyl ether and sorbitol tri. Allyl ether. It is preferable to use these cross-linking agents because they have good compatibility with the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2) and can carry out efficient cross-linking.

The content of the cross-linking agent (b1) hydrolyzed by alkali in the cross-linking polymer (A) in the present invention depends on the type of the cross-linking agent (b1) and the average degree of polymerization, but the water-soluble vinyl monomer (a1) and Based on the total weight of the hydrolyzable vinyl monomer (a2), it is preferably 0.05 to 1% by weight, more preferably 0.1 to 0.8% by weight, and particularly preferably 0.1 to 0.5% by weight. is there. Within these ranges, excessive separation of the alkaline electrolytic solution can be prevented, so that the long-term discharge characteristics of the battery are further excellent.

The content of the cross-linking agent (b2) that is alkaline and does not hydrolyze in the cross-linking polymer (A) depends on the type of the cross-linking agent (b2), but is a water-soluble vinyl monomer (a1) and a hydrolyzable vinyl monomer (a2). ), It is preferably 0.05 to 1% by weight, more preferably 0.05 to 0.5% by weight, and particularly preferably 0.1 to 0.3% by weight, based on the total weight of). Within these ranges, the long-term discharge characteristics of the battery are further excellent.

The weight ratio [(b1) / (b2)] of the cross-linking agent (b1) in the cross-linking polymer (A) to the cross-linking agent (b2) is preferably 1 to 5, more preferably 1.7 to 4, particularly preferably. Is 1.9 to 3. Within these ranges, excessive separation of the alkaline electrolytic solution can be prevented, so that the long-term discharge characteristics of the battery are further excellent.

The total content of the cross-linking agent (b1) and the cross-linking agent (b2) is preferably 0.10 to 2.0 weight based on the total weight of the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2). %, More preferably 0.30 to 1.0% by weight, and particularly preferably 0.40 to 0.8% by weight. Within these ranges, excessive separation of the alkaline electrolytic solution can be prevented, so that the long-term discharge characteristics of the battery are further excellent. Further, the stability of the negative electrode additive (G) of the alkaline battery is improved, and the long-term stability of the viscosity of the alkaline electrolytic solution containing the negative electrode additive (G) of the alkaline battery is further excellent.

The crosslinked polymer (A) is a monomer composition containing a water-soluble vinyl monomer (a1) and / or a hydrolyzable vinyl monomer (a2) and a crosslinking agent (b), which is an organic iodine compound, an organic tellurium compound, and an organic antimony. It can be obtained by polymerizing in the presence of at least one organic representative element compound selected from the group consisting of a compound and an organic bismuth compound. By adjusting the amount of the organic typical element compound used, the amount of the crosslinked polymer (A) soluble component in the physiological saline and the molecular weight of the crosslinked polymer (A) soluble component in the physiological saline are 100. The gel perm obtained with respect to the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the components of 000 or less and the soluble component of the crosslinked polymer (A) in physiological saline. The ratio of the area of the soluble component having a molecular weight of 100,000 or less to the total area of the chromatogram of the ion chromatography method can be set in a desired range.

The organic iodine compound, the organic tellurium compound, the organic antimony compound, and the organic bismuth compound are not limited as long as they are organic typical element compounds that act as dormant species for radical polymerization, and the organic iodine compounds described as dormant species in WO2011 / 016166, WO2004. The organic tellurium compound described in / 014848, the organic antimony compound described in WO2006 / 001496, the organic bismuth compound described in WO2006 / 062255, and the like can be used. Among them, the organic main group element compound represented by the following general formula (1) is preferable from the viewpoint of reactivity.
These organic typical element compounds may be used alone or in combination of two or more.

R ¹ and R ² in the general formula (1) independently form a hydrogen atom, a saturated hydrocarbon group having 1 to 7 carbon atoms, or at least one non-additive polymerizable double bond or at least one non-additive polymerizable triple bond, respectively. It is a monovalent group having 1 to 7 carbon atoms, and R ³ is an n-valent saturated hydrocarbon group having 1 to 7 carbon atoms or at least one non-additive polymerizable double bond or at least one non-additive polymerizable triple bond. It is an n-valent group having a bond and having 2 to 12 carbon atoms, except that at least one of R ¹ to R ³ in one molecule is the above-mentioned corresponding non-additive polymerizable double bond or at least. It is a group having one non-additive polymerizable triple bond, n is an integer of 1 to 3, R ¹ and R ² may be bonded to each other when n is 1, and X ¹ is a tellurium element. , A monovalent organic typical element group or an iodo group having an antimonal element or a bismuth element.

In the present specification, the non-additive polymerizable double bond (hereinafter, also simply referred to as a non-polymerizable double bond) and the non-additive polymerizable triple bond (hereinafter, also simply referred to as a non-polymerizable triple bond) are unsaturated bonds. Of these, the bonds excluding the addition polymerizable unsaturated bond (additional polymerizable carbon-carbon double bond and addition polymerizable carbon-carbon triple bond, respectively), and are non-additive polymerizable double bond and non-additive polymerizable double bond. The triple bond includes a carbon-oxygen double bond contained in a carbonyl group, a carbon-nitrogen triple bond contained in a nitrile group, a carbon-carbon double bond constituting an aromatic hydrocarbon, and oxygen constituting a heteroaromatic compound. -Nitrogen double bond, carbon-nitrogen double bond, etc., among which carbon-oxygen double bond contained in carbonyl group, carbon-nitrogen triple bond contained in nitrile group and carbon constituting aromatic hydrocarbon -Carbon double bonds are preferred.

When R ¹ and R ² are saturated hydrocarbon groups having 1 to 7 carbon atoms, the saturated hydrocarbon groups having 1 to 7 carbon atoms are linear saturated hydrocarbon groups having 1 to 7 carbon atoms (methyl group, ethyl). Group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, etc.) and branched saturated hydrocarbon group with 1 to 7 carbon atoms (i-propyl group, isobutyl group, s-butyl group, t -Butyl group, isopentyl group, neopentyl group, t-pentyl group, 1-methylbutyl group, isohexyl group, s-hexyl group, t-hexyl group, neohexyl group, heptyl group, etc.). Among them, a linear saturated hydrocarbon group having 1 to 5 carbon atoms is preferable from the viewpoint of solubility and polymerizable property, and a linear saturated hydrocarbon group having 1 to 3 carbon atoms is more preferable.

When R ¹ and R ² are monovalent groups having at least one non-polymerizable double bond or at least one non-polymerizable triple bond and having 1 to 7 carbon atoms, the preferred group is a carboxy (salt) group. (Carbon number 1, carbon-oxygen double bond), phenyl group (carbon number 6, non-polymerizable carbon-carbon double bond), cyano group (carbon number 1, carbon-nitrogen triple bond), cyanomethyl group (carbon number) 2. Carbon-nitrogen triple bond), cyanoethyl group (3 carbons, carbon-nitrogen triple bond), cyanopropyl group (4 carbons, carbon-nitrogen triple bond), cyanobutyl group (5 carbons, carbon-nitrogen triple bond) ), Cyanopentyl group (6 carbons, carbon-nitrogen triple bond), cyanohexyl group (7 carbons, carbon-nitrogen triple bond), carboxymethyl group (2 carbons, carbon-oxygen double bond), carboxyethyl Group (3 carbons, carbon-oxygen double bond), carboxypropyl group (4 carbons, carbon-oxygen double bond), carboxybutyl group (5 carbons, carbon-oxygen double bond), carboxypentyl group (4 carbons, carbon-oxygen double bond) 6 carbons, carbon-oxygen double bond), carboxyhexyl group (7 carbons, carbon-oxygen double bond), benzyl group (7 carbons, non-polymerizable carbon-carbon double bond), methoxycarbonyl group (7 carbons, non-polymerizable carbon-carbon double bond) Carbon number 2, carbon-oxygen double bond), ethoxycarbonyl group (carbon number 3, carbon-oxygen double bond), propyloxycarbonyl group (carbon number 4, carbon-oxygen double bond), butyloxycarbonyl group (carbon number 4, carbon-oxygen double bond) 5 carbons, carbon-oxygen double bond), pentyloxycarbonyl group (6 carbons, carbon-oxygen double bond), hexyloxycarbonyl group (7 carbons, carbon-oxygen double bond), hydroxyethoxycarbonyl group (3 carbons, carbon-oxygen double bond), hydroxypropyloxycarbonyl group (4 carbons, carbon-oxygen double bond), hydroxybutyloxycarbonyl group (5 carbons, carbon-oxygen double bond), hydroxy Examples thereof include a pentyloxycarbonyl group (6 carbons, carbon-oxygen double bond) and a hydroxyhexyloxycarbonyl group (7 carbons, carbon-oxygen double bond), and more preferably, a carboxy (salt) group, It is a cyano group, a carboxymethyl group and a carboxyethyl group.
Examples of the salt include alkali metal (lithium, sodium, potassium, etc.) salt, alkaline earth metal (magnesium, calcium, etc.) salt, ammonium (NH ₄ ) salt, and the like. Among these salts, an alkali metal salt and an ammonium salt are preferable, and an alkali metal salt is more preferable, and a sodium salt is particularly preferable, from the viewpoint of the amount of absorption of a 40 wt% potassium hydroxide aqueous solution.

R ³ is an n-valent saturated hydrocarbon group having 1 to 7 carbon atoms or an n-valent group having 2 to 12 carbon atoms having at least one non-polymerizable double bond or at least one non-polymerizable triple bond. , N is an integer of 1 to 3.

Of n-valent saturated hydrocarbon group having 1 to 7 carbon atoms represented by R ^3, 1 valent The saturated hydrocarbon group, straight-chain saturated hydrocarbon group having 1 to 7 carbon atoms having 1 to 7 carbon atoms (Methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, heptyl group, etc.) and branched saturated hydrocarbon group with 1 to 7 carbon atoms (i-propyl group, isobutyl). Group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, t-pentyl group, 1-methylbutyl group, isohexyl group, s-hexyl group, t-hexyl group, neohexyl group, isoheptyl group, etc.) Be done.
Of n-valent saturated hydrocarbon group having 1 to 7 carbon atoms represented by R ^3, examples of the divalent saturated hydrocarbon group having 1 to 7 carbon atoms, a divalent straight-chain saturated having 1 to 7 carbon atoms A hydrocarbon group (methylene group, ethylene group, propylene group, butylene group, penten group, hexene group, heptene group, etc.) and a divalent branched saturated hydrocarbon group having 1 to 7 carbon atoms (isopropylene group, isobutylene group, s) -Butylene group, t-butylene group, isopentylene group, neopentylene group, t-pentylene group, 1-methylbutylene group, isohexylene group, s-hexylene group, t-hexylene group, neohexylene group, isoheptylene group, etc.).
Among the n-valent saturated hydrocarbon groups having 1 to 7 carbon atoms represented by R ³ , the trivalent saturated hydrocarbon group having 1 to 7 carbon atoms includes a methine group and the like.
Of n-valent saturated hydrocarbon group having 1 to 7 carbon atoms represented by R ^3, a methyl group, methylene group and methine group are preferred, more preferred is a methyl group and methylene group.

Of the n-valent groups in which R ³ has at least one non-polymerizable double bond or at least one non-polymerizable triple bond and has 2 to 12 carbon atoms, the monovalent groups are R ¹ and R ² . The same groups as those exemplified are mentioned, and so are the preferred ones.
When R ³ is a divalent group having at least one non-polymerizable double bond or at least one non-polymerizable triple bond and having 2 to 12 carbon atoms, a preferred group is a benzenediyl group (6 carbon atoms). , Non-polymerizable carbon-carbon double bond), 1-methoxycarbonyl-carbonyloxyethylene oxycarbonyl group (6 carbons, oxygen-oxygen double bond) and carbonyloxyethylene carbonyl group (4 carbons, oxygen-oxygen dibond) (Double bond) and the like.
When R ³ is a trivalent group having at least one non-polymerizable double bond or at least one non-polymerizable triple bond and having 2 to 12 carbon atoms, a benzenetriyl group (carbon number) is preferable. 6. Non-polymerizable carbon-carbon double bond) and 2-carbonyloxy-carbonyloxypropylene carbonyl group (5 carbon atoms, oxygen-oxygen double bond) and the like.

When n is 1, R ¹ and R ² may be bonded to each other, and preferred groups having a ring structure formed by bonding R ¹ and R ² to each other are a γ-butyrolactonyl group and Examples include a fluorenyl group. The group in which R ¹ and R ² are bonded to each other to form a ring structure contains a carbon atom to which R ¹ and R ² are bonded in the ring structure.

X ¹ is a monovalent main group or iodo group having a tellurium element, an antimony element or a bismuth element, preferably a methylteranyl group, a dimethylstibanyl group, a dimethylbismutanyl group and an iodine group, and more preferably. Methyltelnaryl groups and iodo groups, particularly preferably iodo groups.

Among the organic typical element compounds represented by the general formula (1), those having an iodo group include 2-iodopropionitrile, 2-iodo-2-methylpropionitrile, α-iodobenzyl cyanide, and 2 -Iodopropionic acid amide, ethyl-2-iodo-2-methylpropionate, methyl 2-iodo-2-methylpropionic acid, propyl 2-iodo-2-methylpropionic acid, 2-iodo-2-methylpropionic acid Butyl, 2-iodo-2-methylpropionic acid pentyl, 2-iodo-2-methylpropionic acid hydroxyethyl, 2-iodo-2-methylpropionic acid (salt), 2-iodopropionic acid (salt), 2-iodine Acetic acid (salt), methyl 2-iodoacetate, ethyl 2-iodoacetate, ethyl 2-iodopentanoate, methyl 2-iodopentanoate, 2-iodopentanoic acid (salt), 2-iodohexanoic acid (salt), 2 -Iodoheptanoic acid (salt), diethyl 2,5-diiodoadipine, 2,5-diiodoadipine acid (salt), dimethyl 2,6-diiodo-heptanediate, 2,6-diiodo-heptanoic acid (Salt), α-iodo-γ-butyrolactone, 2-iodoacetophenone, benzyl iodide, 2-iodo-2-phenylacetic acid (salt), 2-iodo-2-phenylacetate methyl, 2-iodo-2-phenyl Ethyl acetate, 2-iodo-2- (4'-methylphenyl) ethyl acetate, 2-iodo-2-phenylacetic acid-hydroxyethyl, 2-iodo-2- (4'-nitrophenyl) ethyl acetate, 4-nitro Benzyl iodide, (1-iodoethyl) benzene, iododiphenylmethane, 9-iodo-9H-fluorene, p-xylylene diiodide, 1,4-bis (1'-iodoethyl) benzene, ethylene glycol bis (2-methyl- 2-iodo-propionate), tris (2-methyl-iodopropionic acid) glycerol, 1,3,5-tris (1'-iodoethylbenzene), ethylene glycol bis (2-iodo-2phenylacetate) and the like. ..

Among the organic typical element compounds represented by the general formula (1), those having a tellurium element include 2-methylteranylpropionitrile, 2-methyl-2-methylteranylpropionitrile, and α-methyltera. Nylbenzyl cyanide, 2-methylteranylpropionic acid amide, ethyl-2-methyl-2-methylteranyl-propionate, methyl 2-methyl-methylteranylpropionate, propyl 2-methyl-methylteranylpropionate, 2- Butyl methyl-methylteranylpropionate, pentyl 2-methyl-methylteranylpropionate, hydroxyethyl 2-methyl-methylteranylpropionate, 2-methyl-2-methylteranyl-propionic acid (salt), 2-methyltera Nylpropionic acid (salt), 2-methylteranylacetic acid (salt), methyl 2-methylteranylacetate, ethyl 2-methylteranylacetate, ethyl 2-methylteranylpentanoate, methyl 2-methylteranylpentanoate, 2-methylteranyl Pentanoic acid (salt), 2-methylteranylhexanoic acid (salt), 2-methylteranylheptanic acid (salt), diethyl 2,5-dimethylteranyl adipate, 2,5-dimethylteranyl adipate (salt) ), 2,6-Dimethylteranyl-heptanediate dimethyl, 2,6-dimethylteranyl-heptanedioic acid (salt), α-methylteranyl-γ-butyrolactone, 2-methylteranylacetophenone, 2-methylteranyl-2 -Phenylacetic acid (salt), 2-methylteranyl-2-phenylacetate methyl, 2-methylteranyl-2-phenylacetate ethyl, 2-methylteranyl-2- (4'-methylphenyl) ethyl acetate, 2-methylteranyl-2-phenyl -Hydroxyethyl acetate, 2-methylteranyl-2- (4'-nitrophenyl) ethyl acetate, (1-methylteranylethyl) benzene, methylteranyldiphenylmethane, 9-methylteranyl-9H-fluorene, 1,4-bis ( 1'-Methylteranylethyl) benzene, ethylene glycol bis (2-methyl-2-methylteranyl-propionate), tris (2-methyl-methylteranylpropionic acid) glycerol, 1,3,5-tris (1'- Methylteranyl ethylbenzene), ethylene glycol bis (2-methylteranyl-2 phenylacetate) and the like.

Among the organic typical element compounds represented by the general formula (1), those having an antimonic element include 2-dimethylstivanyl propionitrile, 2-methyl-2-dimethylstivanyl propionitrile, and α-dimethylsti. Vanylbenzyl cyanide, 2-dimethylstivanylpropionic acid amide, ethyl-2-methyl-2-dimethylstibanyl-propionate, methyl 2-methyl-dimethylstibanylpropionate, propyl 2-methyl-dimethylstibanylpropionate, Butyl 2-methyl-dimethylstibanylpropionate, pentyl 2-methyl-dimethylstibanylpropionate, hydroxyethyl 2-methyl-dimethylstivanylpropionate, 2-methyl-2-dimethylstivanyl-propionic acid (salt), 2-Dimethylstibanyl propionic acid (salt), 2-dimethylstivanylacetic acid (salt), 2-dimethylstivanylmethylacetate, 2-dimethylstivanylacetate, ethyl 2-dimethylstivanylpentanoate, 2-dimethylsti Methyl vanylpentate, 2-dimethylstibanylpentanoic acid (salt), 2-dimethylstivanylhexanoic acid (salt), 2-dimethylstivanylheptanic acid (salt), diethyl 2,5-didimethylstivanyladipate, 2,5-Didimethylstivanyl adiponic acid (salt), 2,6-didimethylstivanyl-dimethyl heptanedioate, 2,6-didimethylstivanyl-heptanedioic acid (salt), α-dimethylstivanyl- γ-Butyrolactone, 2-dimethylstivanyl acetophenone, 2-dimethylstivanyl-2-phenylacetic acid (salt), 2-dimethylstivanyl-2-phenylacetate methyl, 2-dimethylstivanyl-2-phenylacetate ethyl, 2 -Dimethylstivanyl-2- (4'-methylphenyl) ethyl acetate, 2-dimethylstivanyl-2-phenylacetate-hydroxyethyl, 2-dimethylstivanyl-2- (4'-nitrophenyl) ethyl acetate, ( 1-Dimethylstivanylethyl) benzene, dimethylstivanyldiphenylmethane, 9-dimethylstivanyl-9H-fluorene, 1,4-bis (1'-dimethylstivanylethyl) benzene, ethyleneglycolbis (2-methyl-2- Dimethylstivanyl-propionate), tris (2-methyl-dimethylstivanylpropionic acid) glycerol, 1,3,5-tris (1'-dimethylstivanylethylbenzene) and ethylene glycol bis ( 2-Dimethylstivanyl-2 phenylacetate) and the like.

Among the organic typical element compounds represented by the general formula (1), those having a bismuth element include 2-dimethylbismutanyl propionitrile, 2-methyl-2-dimethylbismutanyl propionitrile, and α-. Dimethylbismutanylbenzyl cyanide, 2-dimethylbismutanylpropionic acid amide, ethyl-2-methyl-2-dimethylbismutanylpropionate, methyl 2-methyl-dimethylbismutanylpropionate, 2-methyl- Propyl dimethylbismutanylpropionate, butyl 2-methyl-dimethylbismutanylpropionate, pentyl 2-methyl-dimethylbismutanylpropionate, hydroxyethyl 2-methyl-dimethylbismutanylpropionate, 2-methyl-2 -Dimethylbismutanylpropionic acid (salt), 2-dimethylbismutanylpropionic acid (salt), 2-dimethylbismutanylacetic acid (salt), 2-dimethylbismutanylacetic acid methyl, 2-dimethylbismutanylacetic acid Ethyl, ethyl 2-dimethylbismutanylpentanoate, methyl 2-dimethylbismutanylppentanoate, 2-dimethylbismutanylpupanoic acid (salt), 2-dimethylbismutanylhexanoic acid (salt), 2- Didimethylbismutanyl heptanic acid (salt), diethyl 2,5-didimethylbismutanyl adipate, 2,5-didimethylbismutanyl adiponic acid (salt), 2,6-didimethylbismutanyl heptaniic acid Dimethyl, 2,6-didimethylbismutanyl heptaniic acid (salt), α-dimethylbismutanyl γ-butyrolactone, 2-dimethylbismutanyl acetphenone, 2-dimethylbismutanyl 2-phenylacetic acid (salt), 2-Dimethylbismutanyl 2-Methyl phenylacetate, 2-Dimethylbismutanyl 2-Ethylphenylacetate, 2-Dimethylbismutanyl 2- (4'-methylphenyl) Ethyl acetate, 2-Dimethylbismutanyl 2- Phenylacetic acid-hydroxyethyl, 2-dimethylbismutanyl 2- (4'-nitrophenyl) ethyl acetate, (1-dimethylbismutanylethyl) benzene, dimethylbismutanyldiphenylmethane, 9-dimethylbismutanyl 9H-fluorene , 1,4-bis (1'-dimethylbismutanylethyl) benzene, ethylene glycol bis (2-methyl-2-dimethylbismutanylpropionate), tris (2-methyl-dimethylbismutanylpropionic acid) Gglycerol, 1,3,5-tris (1'-dimethylbi) Sumtanylethylbenzene) and ethylene glycol bis (2-dimethylbismutanyl 2 phenylacetate) and the like.

Of these, 2-iodo-2-methylpropionitrile, ethyl-2-iodo-2-methylpropionate, 2-iodo-2-methylpropionic acid (salt), and 2-iodoacetic acid (salts) are preferred. Salt), methyl 2-iodoacetate, diethyl 2,5-diiodoadipate, 2,5-diiodoadiponic acid, ethylene glycol bis (2-methyl-2-iodo-propionate), ethylene glycol bis (2-iodo) -2phenylacetate), 2-methylteranylpropionitrile, ethyl-2-methyl-2-methylteranyl-propionate, diethyl 2,5-bismethylteranyl adipate, ethyleneglycolbis (2-methyl-2-methylteranyl) -Propionate), ethylene glycol bis (2-methylteranyl-2phenylacetate), 2-dimethylstivanyl propionitrile, ethyl-2-methyl-2-dimethylstivanyl-propionate and 2-dimethylbismutanyl propionitrile and It is ethyl-2-methyl-2-dimethylbismutanyl propionate.

The amount of the organic main group element compound used is preferably 0.0005 to 0.1 based on the weights of the above-mentioned monomers (a1), (a2), cross-linking agent (b) and other monomers (a3) used if necessary. By weight%, more preferably 0.005 to 0.05% by weight. Within these ranges, the amount of the soluble component in the physiological saline and the gel permi obtained for the Mw / Mn of the component having a molecular weight of 100,000 or less and the soluble component in the physiological saline. The ratio of the area of the soluble component having a molecular weight of 100,000 or less to the total area of the chromatogram of the ion chromatography method was in an appropriate range, and the negative electrode additive (G) for the alkaline battery was added. The viscosity of the negative electrode material becomes appropriate, the zinc powder and the like do not settle, and the impact resistance and discharge characteristics are good.

A method for polymerizing a monomer composition containing a water-soluble vinyl monomer (a1) and / or a hydrolyzable vinyl monomer (a2) and a cross-linking agent (b) in the presence of the above-mentioned organic typical element compound is an aqueous solution polymerization. , Known polymerization methods such as suspension polymerization, massive polymerization, reverse phase suspension polymerization and emulsion polymerization can be applied. In these polymerization methods, the organic main group element compound may be present in the monomer or the monomer aqueous solution, or may be added at the time of adding the initiator or the like to the monomer solution or the like.

Of these polymerization methods, aqueous polymerization, suspension polymerization, reverse phase suspension polymerization and emulsion polymerization are preferable from the viewpoint of discharge characteristics and impact resistance, and aqueous solution polymerization, reverse phase suspension polymerization and emulsion polymerization are more preferable. Particularly preferred are aqueous solution polymerization and reverse phase suspension polymerization. Known polymerization initiators, chain transfer agents and / or solvents and the like can be used for these polymerizations.

The method of polymerizing by aqueous solution polymerization, suspension polymerization, reverse phase suspension polymerization and emulsion polymerization may be a known method, for example, a method of polymerizing using a radical polymerization initiator, a method of irradiating with radiation, ultraviolet rays or electron beams. Can be mentioned.

When a radical polymerization initiator is used, the initiator used is an azo compound [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, etc.] Sodium persulfate, etc.], organic peroxide [di-t-butyl peroxide, cumenehydroperoxide, etc.], redox initiator [alkali metal salt sulfite or bicarbonate, ammonium sulfite, ammonium bicarbonate, L- A combination of a reducing agent such as ascorbic acid and a peroxide such as an alkali metal salt persulfate, ammonium persulfate, and hydrogen peroxide solution] and the like. These may be used alone or in combination of two or more.

The polymerization temperature varies depending on the type of initiator used, but is preferably −10 ° C. to 100 ° C., more preferably −10 ° C. to 80 ° C. from the viewpoint of increasing the degree of polymerization of the polymer.

The amount of the initiator is also not particularly limited, but the degree of polymerization of the polymer is based on the total weight of the vinyl monomers (a1), (a2), the cross-linking agent (b) and other monomers (a3) used if necessary. From the viewpoint of increasing the value, 0.000001 to 3.0% by weight is preferable, and 0.000001 to 0.5% by weight is more preferable.

In the case of aqueous solution polymerization, the polymerization concentration of the monomer varies depending on other polymerization conditions, but the water-soluble vinyl monomer (a1) and the hydrolyzable vinyl monomer (a2) are parallel to the polymerization reaction when the polymerization concentration is increased. As a result, pseudo-crosslinking (self-crosslinking) of the monomer itself is likely to occur, leading to a decrease in the amount of absorption and a decrease in the average degree of polymerization of the polymer, and it is difficult to control the temperature during polymerization. The polymerization concentration is preferably 10 to 40% by weight, more preferably 10 to 30% by weight, because the polymerization concentration tends to increase. The polymerization temperature is preferably −10 to 100 ° C., more preferably −10 to 80 ° C. The amount of dissolved oxygen during polymerization depends on the amount of radical initiator added and the like, but is preferably 0 to 2 ppm (2 × 10 ^-4 % by weight or less), and more preferably 0 to 0.5 ppm (0.5 ×). ^10-4 % by weight or less). Within these ranges, a crosslinked polymer (A) having a high degree of polymerization can be produced.

When a monomer having an acid group such as (meth) acrylic acid is used, the degree of neutralization of the acid group at the time of polymerization is such that a predetermined amount of the cross-linking agents (b1) and (b2) can be completely dissolved in the aqueous monomer solution. There is no particular limitation. However, compared to (b1), (b2) has poor water solubility, and in particular, the solubility of a monomer having an acid group in an aqueous solution is extremely low, and even if a predetermined amount of (b2) is added, (b2) is obtained from the aqueous monomer solution. It may be separated and the predetermined cross-linking may not be possible. Therefore, the degree of neutralization of the monomer having an acid group at the time of polymerization is preferably 0 to 30 mol%, and if necessary, further neutralization is performed after polymerization, and after polymerization in an unneutralized state, after polymerization if necessary. It is more preferable to neutralize. Further, when the monomer having an acid group is polymerized under the same conditions, the lower the degree of polymerization is, the higher the degree of polymerization is likely to be. Therefore, in order to increase the degree of polymerization of the polymer, the degree of polymerization is low. It is preferable to carry out polymerization.

The reverse phase suspension polymerization method is a polymerization method in which an aqueous solution of a monomer is suspended and dispersed in a hydrophobic organic solvent typified by hexane, toluene, xylene and the like in the presence of a dispersant and polymerized. Also in the polymerization method, the monomer concentration in the aqueous monomer solution is preferably 10 to 40% by weight, more preferably 10 to 30% by weight, as described above. Within these ranges, a crosslinked polymer (A) having a high degree of polymerization can be produced.

Regarding this reverse phase suspension polymerization method, a dispersant may be used at the time of polymerization. Examples of the dispersant include sorbitan fatty acid esters such as sorbitan monostearate ester having an HLB (Hydrophile-Lipofile Balance) value of 3 to 8, glycerin fatty acid esters such as glycerin monostearic acid ester, and sucrose distearate ester. Hydrophiles in molecules such as surfactants such as sugar fatty acid esters, maleides of ethylene / acrylic acid copolymers, maleides of ethylene / vinyl acetate copolymers, and styrene sulfonic acid (salt) / styrene copolymers. A polymer dispersant having a sex group and soluble in a solvent for dispersing the aqueous monomer solution (hydrophilic group; 0.1 to 20% by weight, weight average molecular weight; 1,000 to 1,000,000), etc. However, when a polymer dispersant is used as the dispersant, the size of the suspended particles of the monomer aqueous solution in the solvent can be easily adjusted, and the crosslinked polymer (A) having the required particle size can be used. It is preferable because a hydrogel can be produced.

From the viewpoint of the discharge characteristics of the alkaline battery, the amount of the dispersant used 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. The weight ratio (W / O ratio) of the aqueous monomer solution and the hydrophobic organic solvent in the reverse phase suspension polymerization is preferably 0.1 to 2.0, more preferably 0.3 to 1.0. Within these ranges, the particle size of the crosslinked polymer (A) can be further adjusted.

In the production of the crosslinked polymer (A), the average degree of polymerization of the polymer when the polymer is produced under exactly the same conditions except that the crosslinking agent (b) is not used is preferably 5,000 to 1,000,000. It is more preferable to carry out the polymerization under the conditions that are, more preferably 10,000 to 1,000,000. When the polymerization is carried out under the condition that the average degree of polymerization is 5,000 or more, the viscosity of the high-concentration alkaline aqueous solution to which the negative electrode additive (G) of the alkaline battery is added is reduced and / or by using an appropriate amount of the cross-linking agent. It is possible to prevent an increase in spinnability. The measurement of the average degree of polymerization can be carried out in the same manner as the method for measuring the weight average molecular weight and the number average molecular weight of the soluble component of the crosslinked polymer (A) in physiological saline, which will be described later.

In the present invention, the crosslinked polymer (A) obtained by aqueous solution polymerization, reverse phase suspension polymerization or the like is obtained as a gel containing water (hydrous gel). The hydrogel is used as an additive (G) for the negative electrode of an alkaline battery after being dried. Regarding the method of drying the hydrogel, in the case of aqueous polymerization, the hydrogel is subdivided to some extent (the level of subdivision is about 0.5 to 20 mm square) or noodles with a meat chopper or a cutter type coarse crusher, and if necessary. After neutralizing the hydrogel by adding an aqueous alkali metal hydroxide solution, etc., air-permeable drying (for example, laminating the hydrogel on a punching metal or screen and forcibly aerating hot air at 50 to 150 ° C. (Drying) and aeration drying (a hydrogel is placed in a container, hot air is aerated and circulated to dry, and the gel is further subdivided and dried by a machine such as a rotary kiln). Of these, air-permeable drying is preferable because it enables efficient drying in a short time. On the other hand, in the case of reverse phase suspension polymerization, the method for drying the hydrogel is that the polymerized hydrogel and the organic solvent are solid-liquid separated by a method such as decantation and then dried under reduced pressure (decompression: about 100 to 50,000 Pa). Alternatively, air drying is generally performed.

As another drying method of the hydrogel in the aqueous solution polymerization, for example, there is a contact drying method in which the hydrogel is compression-stretched and dried on a drum dryer, but since the hydrogel has poor thermal conductivity, it is necessary to perform drying. It is necessary to make a thin film of hydrogel on the drum. However, since the material of a commercially available drum dryer is generally made of a metal having a lower ionization tendency than zinc such as iron, chromium and nickel, the frequency of contact with the drum metal surface per hydrogel becomes extremely high. Further, since the hydrogel is a hydrogel such as poly (meth) acrylic acid (salt), the content of metal elements having a lower ionization tendency than zinc eluted in the gel is higher. Further, since the contact frequency between the water-containing gel and the drum is extremely high and the water-containing gel has high adhesiveness, it is necessary to bring a knife-like object into contact with the drum dryer to peel the dried product from the drum dryer. And the mechanical wear of the knife causes the metal surface of the drum or knife to wear and the metal to get mixed into the dried material. As described above, when a contact drying method such as a drum dryer is used, metal ions and metal powder are likely to be mixed in the negative electrode additive (G) of the alkaline battery, and the metal having a lower ionization tendency than zinc (standard electrode potential). Is a metal having a lower value than zinc, and contains a considerably large amount of Cr, Fe, Ni, Sn, Pb, Cu, Hg, Ag and other metals) ions and metal powder. When the negative electrode additive (G) of these alkaline batteries is used as the negative electrode additive (G) of an alkaline battery, the zinc powder in the battery is placed between the metal ion or the metal powder having a lower ionization tendency than zinc. Because of the formation, hydrogen gas is generated by electrolysis, which raises the pressure inside the battery, which may cause the outflow of alkaline electrolyte and, in the worst case, damage to the battery. Further, the thin film-like dried product obtained by compressing and stretching the hydrogel on a drum dryer and dried is then pulverized to adjust the particle size of the dried product to a desired particle size, but the particles are scaly. Therefore, the strength is much weaker than that of the crushed block-shaped dried product obtained by the air-permeable drying method or the aeration drying method. Therefore, when the gel is swollen in a high-concentration alkaline aqueous solution and mechanically stirred and mixed with the zinc powder, the swollen gel is destroyed and the gel becomes smaller. Therefore, it is preferable not to use a contact drying method such as a drum dryer.

In the present invention, the drying temperature at the time of drying the hydrogel varies depending on the dryer used, the drying time, and the like, but is preferably 50 to 150 ° C, more preferably 80 to 130 ° C. If the drying temperature is 50 ° C. or lower, it takes a long time to dry, and the productivity is significantly lowered. When the temperature is 50 ° C. or higher, drying does not require a long time and is efficient. The drying time also varies depending on the model of the dryer used, the drying temperature, and the like, but is preferably 5 to 300 minutes, more preferably 5 to 120 minutes.

The dried product of the crosslinked polymer (A) thus obtained is pulverized and pulverized if necessary. The crushing method may be a known method, for example, an impact crusher (pin mill, cutter mill, skillel mill, ACM pulperizer, etc.) or an air crusher (jet crusher, etc.).

For the powdered crosslinked polymer (A), if necessary, a dry powder having a desired particle size can be collected using a sieve machine equipped with a screen (vibration sieve machine, centrifugal sieve machine, etc.).

In the present invention, it is preferable to remove mixed metal powder such as iron by using an iron remover using magnetism at an arbitrary stage after drying. However, even if iron is removed with a high degree of precision using an iron remover, it is difficult for the iron remover to remove non-magnetic metals, and magnetic metals are also contained inside the dried polymer particles. It cannot be removed if it is stuck or adheres to dry particles. Therefore, it is desirable to give due consideration to the production equipment so that these metals are not mixed from the beginning.

The amount of soluble component of the crosslinked polymer (A) in the present invention in physiological saline (0.9% by weight sodium chloride aqueous solution; the same applies to other parts in the present specification) is based on the weight of (A). It is 5 to 40% by weight, preferably 5 to 25% by weight, and more preferably 5 to 15% by weight.
When the amount of soluble components is in these ranges, the viscosity of the alkaline electrolytic solution to which the negative electrode additive (G) of the alkaline battery is added is in a suitable range, and the negative electrode material drains well, so that a battery with stable quality can be obtained. Since it can be manufactured and sedimentation of zinc powder or the like in the negative electrode material can be prevented, a battery having excellent discharge characteristics over time can be produced. When the amount of the soluble component exceeds 40% by weight, the alkaline electrolytic solution to which the negative electrode additive (G) of the alkaline battery is added becomes spinnable, the drainage of the negative electrode material is remarkably deteriorated, and the filling amount varies. The quality is not stable. If the amount of the soluble component is less than 5% by weight, the viscosity of the alkaline electrolytic solution to which the negative electrode additive (G) of the alkaline battery is added becomes low, and zinc powder or the like is settled, resulting in deterioration of impact resistance and discharge characteristics. ..

The amount of the soluble component of the crosslinked polymer (A) in physiological saline can be measured by the following method.
<Method of measuring the amount of soluble component in physiological saline of (A)>
1 g of the negative electrode additive (G) for an alkaline battery is precisely weighed (the precision value is S0), added to 250 ml of physiological saline, stirred for 3 hours, and then the swollen gel is applied to filter paper (Advantech Filter Paper). Remove with No. 1 qualitative filter paper). The filtrate obtained after removing the gel is used as an extract of soluble components.
About 25 ml of the extract of the soluble component obtained by the above method is placed in an eggplant-shaped flask having a capacity of 50 ml, and water is distilled off under reduced pressure using an evaporator. About 25 ml of the extract is added to the eggplant-shaped flask, and the operation of distilling water under reduced pressure is repeated to distill off water for the entire amount of the extract. Next, the eggplant-shaped flask containing the residue is allowed to stand in a circulating air dryer at 130 ° C. for 90 minutes, and then allowed to stand in a desiccator for 15 minutes to cool the eggplant-shaped flask to room temperature. After cooling, the weight (S1) of the residue in the eggplant-shaped flask is measured. The same operation is performed on the same amount of physiological saline as the extract used in the previous operation, and the weight (S2) of the residue after cooling is measured. The weight of the residue after cooling is obtained by subtracting the weight of the eggplant-shaped flask measured in advance from the weight of the eggplant-shaped flask containing the residue after cooling.
Using (S0), (S1) and (S2) obtained above, the amount of soluble component is calculated from the following formula.
Soluble component amount (%) = (S1-S2) ÷ S0 × 100

In the present invention, the weight average molecular weight (hereinafter, abbreviated as Mw) with respect to the number average molecular weight (hereinafter, abbreviated as Mn) of the component having a molecular weight of 100,000 or less among the components soluble in the physiological saline of the crosslinked polymer (A). The ratio (Mw / Mn) of is 4.0 to 6.0, preferably 4.0 to 5.5, and more preferably 4.0 to 5.0.
When Mw / Mn of the component having a molecular weight of 100,000 or less among the soluble components is in this range, the viscosity of the alkaline electrolytic solution to which the negative electrode additive (G) for the alkaline battery is added becomes a suitable range, and the negative electrode material Better drainage. Therefore, it is possible to manufacture a battery with stable quality and prevent the zinc powder or the like from settling in the negative electrode material, so that a battery having excellent discharge characteristics over time can be produced. When the Mw / Mn of the soluble component having a molecular weight of 100,000 or less exceeds 6.0, the amount of the low molecular weight component in the soluble component increases, so that the alkaline electrolytic solution to which the negative electrode additive (G) of the alkaline battery is added Since the viscosity becomes low and zinc powder or the like is settled, the impact resistance and discharge characteristics are deteriorated. When Mw / Mn is less than 4.0, the amount of the high molecular weight component in the soluble component increases, so that the alkaline electrolytic solution to which the negative electrode additive (G) of the alkaline battery is added shows spinnability and the negative electrode. The quality of the battery is not stable because the drainage of the material deteriorates remarkably and the filling amount varies.

In the present invention, the soluble component having a molecular weight of 100,000 or less with respect to the total area of the chromatogram of the gel permeation chromatography method obtained for the soluble component of the crosslinked polymer (A) in physiological saline. The area ratio is 50% or less, preferably 45% or less, and more preferably 40% or less.
When the ratio of the area of the soluble component having a molecular weight of 100,000 or less is in these ranges, the viscosity of the alkaline electrolytic solution to which the negative electrode additive (G) for the alkaline battery is added is in a suitable range. For this reason, it is possible to manufacture a battery in which the negative electrode material drains well and the quality is stable, and it is possible to prevent the zinc powder and the like from settling in the negative electrode material. Can produce excellent batteries. When the ratio of the area of the soluble component having a molecular weight of 100,000 or less exceeds 50%, the amount of the low molecular weight component in the soluble component increases. Therefore, the viscosity of the alkaline electrolytic solution to which the negative electrode additive (G) of the alkaline battery is added. Is lowered, and the zinc powder and the like are settled, so that the impact resistance and the discharge characteristics are deteriorated.

The ratio of the areas of Mw and Mn of the component having a molecular weight of 100,000 or less and the soluble component having a molecular weight of 100,000 or less among the soluble components of the crosslinked polymer (A) in physiological saline is gel permeation chromatography. It is obtained by obtaining a chromatogram of a soluble component by the method (GPC method) and calculating the ratio of Mw, Mn and area in a section having a molecular weight of 100,000 or less.
More specifically, under the following conditions, the area of the chromatographic pattern detected at the elution time of 100,000 or less, based on the molecular weight calculated from the calibration curve obtained using the standard polyethylene oxide as the reference substance, is determined in (A). Let (B) be the area of the chromatographic pattern detected at the elution time having a molecular weight of more than 100,000. The Mw of the component having a molecular weight of 100,000 or less is the measured value of the weight average molecular weight of the above-mentioned (A), and the Mn of the component having a molecular weight of 100,000 or less is the measured value of the number average molecular weight of the above-mentioned (A). The ratio of the area of the component having a molecular weight of 100,000 or less is a value obtained by [(A) / ((A) + (B))] × 100 (%).
Equipment: "HLC-8320" (manufactured by Tosoh Corporation)
Column: "TSK Guard volume PWXL" (1), "TSKgel G60000 PWXL, TSKgel G3000 PWXL" (1) (all manufactured by Tosoh Corporation) connected 1 each Mobile phase: 0.5 wt% sodium acetate Aqueous solution / methanol = 7/3 (volume ratio)
Measuring solution: Extract solution injection amount of soluble component in the above-mentioned method for measuring the amount of soluble component: 50 μl
Flow rate: 1.0 ml / min Measurement temperature: 40 ° C
Detector: Refractive index detector Reference substance: Standard polyethylene oxide

The negative electrode additive (G) of the alkaline battery of the present invention has a range in which problems do not occur in workability and battery characteristics for the purpose of improving the fluidity at the time of filling a mixture of negative electrode substances other than the crosslinked polymer (A). And, if necessary, other additives may be included.
Examples of other additives include thickeners, vibration and shock resistance improvers, discharge characteristic improvers and the like.

Examples of the thickener include CMC (carboxymethyl cellulose), natural gum (guar gum, etc.), uncrosslinked poly (meth) acrylic acid (salt), water-soluble resins such as polyvinyl alcohol, and the like. The particle size of the thickener added as necessary is not particularly limited, but the volume average particle size of the dried product is preferably 0.1 to 100 μm (further, 0.1 to 50 μm). Within this range, handling is easy, such as when mixing with an alkaline electrolytic solution and filling the negative electrode container of the battery.

As the vibration and shock resistance improver, oxides, hydroxides, sulfides and the like of metal elements selected from the group consisting of titanium, indium, tin and bismuth can be used.
Examples of the discharge characteristic improving agent include known compounds such as silicon dioxide and potassium silicate.

When other additives are contained, the content is preferably 0 to 5.0% by weight, more preferably 0 to 3.0% by weight, based on the weight of the alkaline electrolytic solution.

Other additives may be added at any stage {of the cross-linked polymer (A) manufacturing process, the polymerization step, the shredding step, the drying step, the pulverization step, the surface cross-linking step and / or before and after these steps}. Can be done.

The absorption amount of the 40 wt% potassium hydroxide aqueous solution of the negative electrode additive (G) of the alkaline battery of the present invention is preferably 40 to 70 g / g, more preferably 42 to 65 g / g, and particularly preferably 45 to 60. Within these ranges, excessive separation of the alkaline electrolytic solution can be prevented, and the long-term discharge characteristics of the battery are further excellent. In addition, the impact resistance and productivity (process simplification) of alkaline batteries are excellent.

The absorption amount of the 40 wt% potassium hydroxide aqueous solution of the negative electrode additive (G) of the alkaline battery of the present invention is measured by the following method.
<Measuring method of absorption amount of 40 wt% potassium hydroxide aqueous solution>
1.00 g of the measurement sample was placed in a tea bag (length 20 cm, width 10 cm) made of a nylon mesh having a mesh size of 63 μm (JIS Z8801-1: 2006), and placed in 1,000 ml of a 40 wt% potassium hydroxide aqueous solution without stirring. After soaking for 14 hours, the tea bag is hung for 30 minutes to remove excess potassium hydroxide aqueous solution, and the weight (h1) of the tea bag is measured. The temperature of the physiological saline used and the measurement atmosphere shall be 25 ° C ± 2 ° C. The weight (h2) of the tea bag after centrifugal dehydration is measured in the same manner as above except that the measurement sample is not used, and the absorption amount of 0 wt% potassium hydroxide aqueous solution is calculated from the following formula.
Absorption amount of 40 wt% potassium hydroxide aqueous solution (g / g) = (h1)-(h2)

In the present invention, the viscosity (Pa · s) of a mixed solution prepared by adding 2% by weight of the negative electrode additive (G) for an alkaline battery to a 40% by weight potassium hydroxide aqueous solution is 10 to 60, preferably 25. It is ~ 50, more preferably 30-40. If the viscosity of the mixed solution is outside the range of 10 to 60 Pa · s, excessive separation of the alkaline electrolytic solution cannot be prevented, the long-term discharge characteristics of the battery are inferior, and impact resistance and productivity (filling). Sex) gets worse.

The viscosity of a mixed solution prepared by adding 2% by weight of the negative electrode additive (G) for an alkaline battery to a 40% by weight aqueous potassium hydroxide solution is measured by the following method.
<Method of measuring viscosity of mixed solution>
98 parts by weight of a 40 wt% potassium hydroxide aqueous solution and 2 parts by weight of the negative electrode additive (G) of an alkaline battery were stirred and mixed until uniform and left at 25 ° C. for 16 hours, and then the mixed solution was used as a measurement sample and digitally used. A B-type viscometer (manufactured by TOKIMEC) is used for measurement at a measurement temperature of 25 ° C. in accordance with JIS7117-1: 1999. In addition, the rotor No. No. 4 is used, and the measurement is performed at a rotation speed of 3 rpm.

The volume average particle size of the negative electrode additive (G) of the alkaline battery in the present invention is preferably 30 to 400 μm, more preferably 30 to 170 μm, and particularly preferably 30 to 100 μm. When the volume average particle size is in these ranges, the viscosity of the alkaline electrolytic solution to which the negative electrode additive (G) of the alkaline battery is added is in a suitable range, and the negative electrode material drains well. Therefore, it is possible to manufacture a battery with stable quality and prevent the zinc powder or the like from settling in the negative electrode material, so that a battery having excellent discharge characteristics over time can be produced.

The volume average particle size of the negative electrode additive (G) of the alkaline battery of the present invention is such that the negative electrode additive (G) of the alkaline battery is dispersed in methanol and a laser diffraction type particle size distribution measuring device [Microtrack (Nikkiso Co., Ltd.) Manufactured by)].

The liquid separation rate of the negative electrode material containing the negative electrode additive (G) of the alkaline battery of the present invention is preferably 10% by weight or less, more preferably 0.1 to 5% by weight, and particularly preferably 0.1 to 3%. By weight%, most preferably 0.5 to 2.5% by weight. Within these ranges, the long-term discharge characteristics of the battery are further excellent.

The above liquid separation rate is measured by the following method.
<Measurement method of liquid separation rate>
100 parts by weight of a 40 wt% potassium hydroxide aqueous solution, 2 parts by weight of an additive (G) for a negative electrode of an alkaline battery, and 200 parts by weight of a zinc powder having a volume average particle diameter of 200 μm are stirred and mixed until uniform to make a negative electrode material for an alkaline battery. To make. Weigh 75.0 g of this negative electrode material into the bottom of a tea bag made of a nylon screen with an opening of 32 μm (400 mesh) prepared in accordance with JIS K7223-1996, and let stand at 25 ° C. for 168 hours (1 week). .. Then, the tea bag is hung with a clip and allowed to stand to drain water for 30 minutes, and then the weight (W1) (g) of the tea bag after draining is measured. Further, the same operation is performed only with the tea bag without inserting the negative electrode material, and the weight (W2) (g) of the tea bag is measured. The liquid separation rate is calculated by the following formula.
Liquid separation rate (% by weight) = [{75.0}-{W1} + {W2}] / {75.0} x 100

The alkaline battery to which the negative electrode additive (G) of the alkaline battery of the present invention can be applied is not particularly limited, and is a general alkaline battery having a negative electrode material composed of an alkaline electrolytic solution and zinc powder, for example, LR. It can be applied not only to -20 (AA alkaline battery) and LR-6 (AA alkaline battery), but also to various other primary or secondary alkaline batteries. Alkaline batteries generally have a structure in which a positive electrode agent, a current collector rod, and a gel negative electrode are enclosed in an outer can, and the positive electrode agent and the gel negative electrode are separated by a separator or the like.

As a method for filling the alkaline battery with the negative electrode additive (G) of the alkaline battery of the present invention,
(1) Additive (G) for negative electrode of alkaline battery of the present invention, alkaline electrolytic solution (for example, high-concentration potassium hydroxide aqueous solution, if necessary, zinc oxide and the like are contained), zinc powder and the like (in other words, zinc powder). , Zinc alloy powder, or zinc powder and zinc alloy powder), and if necessary, other additives are premixed to prepare a mixture of negative electrode substances, which is filled in the negative electrode container of the battery to obtain a gel negative electrode. Method, in addition, zinc alloy powder means what is usually used as a negative electrode material in an alkaline battery, and is itself known to those skilled in the art.
(2) After filling the negative electrode container of the battery with the negative electrode additive (G) and zinc powder of the alkaline battery of the present invention and other additives if necessary, the alkaline electrolytic solution is filled and the gel-like negative electrode is filled in the container. Can be exemplified as a method of generating.
Of the above, the method (1) described above in which zinc powder or the like can be uniformly dispersed in the negative electrode container of the battery is preferable.

The amount of the negative electrode additive (G) added to the alkaline battery varies depending on the structure of the negative electrode container, the particle size of zinc powder, etc., and the concentration of the alkaline electrolytic solution, but is 0.5 based on the weight of the alkaline electrolytic solution. It is preferably from 10% by weight, more preferably 1.0 to 5.0% by weight. When the addition amount is 0.5 to 10% by weight, the viscosity of the alkaline electrolytic solution containing the gelling agent becomes appropriate, sedimentation of zinc powder and the like can be prevented, and handleability is easy.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Hereinafter, unless otherwise specified, ultrapure water indicates water having an electric conductivity of 0.06 μS / cm or less, and ion-exchanged water indicates water having an electric conductivity of 1.0 μS / cm or less.

<Example 1>
In a 3 liter adiabatic polymerization tank, 380 g of acrylic acid, 0.49 g of pentaerythritol triaryl ether (0.13% by weight of acrylic acid), 1.33 g of trimethylolpropane triacrylate (0.35% by weight of acrylic acid) and After adding 1600 g of ion-exchanged water and stirring and mixing to prepare an acrylic acid aqueous solution, the acrylic acid aqueous solution was cooled to 3 ° C. After cooling, nitrogen was aerated in the acrylic acid aqueous solution at a flow rate of 5 L / min to bring the dissolved oxygen concentration in the acrylic acid aqueous solution to 0.10 ppm or less. The dissolved oxygen concentration was measured using an oxygen concentration meter (ORBISPHERE 510, manufactured by HACH ULTRA) based on the diaphragm electrode method. After confirming that the acrylic acid aqueous solution was at 3 ° C., 2,2'-azobis (2-amidinopropane) hydrochloride (sum) having a concentration of 10% by weight was used as a polymerization initiator in an adiabatic polymerization tank while continuing nitrogen aeration. Kojunyaku Kogyo Co., Ltd., trade name: V-50) aqueous solution 11.40 g, 2-iodo-2-methylpropionitrile (manufactured by TCI) 0.055 g, concentration 1.0 wt% hydrogen peroxide solution 1. 14 g, 1.14 g of an L-ascorbic acid aqueous solution having a concentration of 1.0 wt%, and 0.57 g of an iron (III) aqueous solution having a concentration of 0.1 wt% were added. After the addition of the polymerization initiator, nitrogen aeration was continued for 25 minutes, nitrogen aeration was stopped, and the mixture was allowed to stand for 16 hours to carry out the polymerization reaction. After allowing to stand for 16 hours, the hydrogel obtained by the polymerization reaction was taken out from the polymerization reaction tank.
The water-containing gel taken out was subdivided into a noodle shape with a thickness of 3 to 10 mm using a small meat chopper (manufactured by Royal), and a 49 wt% sodium hydroxide (special grade reagent) aqueous solution was added to the subdivided water-containing gel. After adding 132 g, the mixture was uniformly kneaded into a hydrogel using the small meat chopper to neutralize it.
The neutralized hydrogel was laminated on a SUS screen with an opening of 850 μm to a thickness of 5 cm, and hot air at 150 ° C was blown for 1 hour using a small air-permeable dryer (manufactured by Inoue Metal Co., Ltd.). The water in the hydrogel was evaporated to obtain a dry gel.
After crushing the dried gel with a cooking mixer, a sieve having a mesh size of 150 μm (100 mesh) is used to collect particles having a particle size of 150 μm or less, and the negative electrode additive (G-1) for the alkaline battery of the present invention. Got

<Example 2>
The dried gel obtained in Example 1 is pulverized using a cooking mixer, and then a sieve having a particle size of 45 μm or less is collected using a sieve having a mesh size of 45 μm (330 mesh) to collect a negative electrode of the alkaline battery of the present invention. Additive (G-2) for use was obtained.

<Example 3>
The dried gel obtained in Example 1 is pulverized using a cooking mixer, and then a sieve having a particle size of 250 μm or less is collected using a sieve having a mesh size of 250 μm (60 mesh) to collect a negative electrode of the alkaline battery of the present invention. Additive (G-3) for use was obtained.

<Example 4>
The dried gel obtained in Example 1 was pulverized using a cooking mixer, and then a sieve having a mesh size of 600 μm (26 mesh) was used to collect particles having a particle size of 600 μm or less, and the negative electrode of the alkaline battery of the present invention was collected. Additive (G-4) for use was obtained.

<Example 5>
Same as Example 1 except that the amount of trimethylolpropane triacrylate charged in Example 1 was changed from 1.33 g (0.35% by weight of acrylic acid) to 0.76 g (0.20% by weight of acrylic acid). The negative electrode additive (G-5) for the alkaline battery of the present invention was obtained.

<Example 6>
Except that the amount of trimethylolpropane triacrylate charged in Example 1 was changed from 1.33 g (0.35% by weight of acrylic acid) to 2.09 g (0.55% by weight of acrylic acid), the same as in Example 1. Similarly, an additive (G-6) for the negative electrode of the alkaline battery of the present invention was obtained.

<Example 7>
Same as in Example 1 except that the amount of pentaerythritol triallyl ether charged in Example 1 was changed from 0.49 g (0.13% by weight of acrylic acid) to 0.38 g (0.10% by weight of acrylic acid). The negative electrode additive (G-7) for the alkaline battery of the present invention was obtained.

<Example 8>
Same as in Example 1 except that the amount of pentaerythritol triaryl ether charged in Example 1 was changed from 0.49 g (0.13% by weight of acrylic acid) to 0.76 g (0.20% by weight of acrylic acid). The negative electrode additive (G-8) for the alkaline battery of the present invention was obtained.

<Example 9>
The negative electrode additive (G) for the alkaline battery of the present invention is the same as in Example 1 except that the amount of 2-iodo-2-methylpropionitrile charged in Example 1 is changed from 0.055 g to 0.028 g. -9) was obtained.

<Example 10>
The negative electrode additive (G) for the alkaline battery of the present invention is the same as in Example 1 except that the amount of 2-iodo-2-methylpropionitrile charged in Example 1 is changed from 0.055 g to 0.083 g. -10) was obtained.

<Example 11>
The negative electrode additive alkaline battery of the alkaline battery of the present invention is the same as in Example 1 except that the charge amount of 2-iodo-2-methylpropionitrile in Example 1 is changed from 0.055 g to 0.110 g. Negative electrode additive (G-11) was obtained.

<Example 12>
The amount of trimethylol propantriacrylate charged in Example 1 was changed from 1.33 g (0.35% by weight of acrylic acid) to 0.19 g (0.05% by weight of acrylic acid), and the amount of pentaerythritol triallyl ether charged. From 0.49 g (0.13% by weight of acrylic acid) to 0.19 g (0.05% by weight of acrylic acid), and the amount of 2-iodo-2-methylpropionitrile charged from 0.055 g to 0. An additive (G-12) for the negative electrode of the alkaline battery of the present invention was obtained in the same manner as in Example 1 except that the amount was replaced with 028 g.

<Example 13>
The amount of trimethylolpropane triacrylate of Example 1 charged was changed from 1.33 g (0.35% by weight of acrylic acid) to 3.80 g (1.00% by weight of acrylic acid), and the amount of pentaerythritol triallyl ether charged. From 0.49 g (0.13% by weight of acrylic acid) to 0.76 g (0.20% by weight of acrylic acid), and the amount of 2-iodo-2-methylpropionitrile charged from 0.055 g to 0. An additive (G-13) for the negative electrode of the alkaline battery of the present invention was obtained in the same manner as in Example 1 except that the amount was replaced with 028 g.

<Example 14>
The amount of trimethylolpropane triacrylate of Example 1 charged was changed from 1.33 g (0.35% by weight of acrylic acid) to 3.80 g (1.00% by weight of acrylic acid), and the amount of pentaerythritol triallyl ether charged. From 0.49 g (0.13% by weight of acrylic acid) to 3.80 g (1.00% by weight of acrylic acid), and the amount of 2-iodo-2-methylpropionitrile charged from 0.055 g to 0. An additive (G-14) for the negative electrode of the alkaline battery of the present invention was obtained in the same manner as in Example 1 except that the amount was replaced with 028 g.

<Example 15>
The amount of trimethylolpropan triacrylate charged in Example 1 was changed from 1.33 g (0.35% by weight of acrylic acid) to 0.95 g (0.25% by weight of acrylic acid), and the amount of pentaerythritol triallyl ether charged. From 0.49 g (0.13% by weight of acrylic acid) to 0.19 g (0.05% by weight of acrylic acid), and the amount of 2-iodo-2-methylpropionitrile charged from 0.055 g to 0. An additive (G-15) for the negative electrode of the alkaline battery of the present invention was obtained in the same manner as in Example 1 except that the amount was replaced with 028 g.

<Example 16>
The amount of trimethylol propantriacrylate charged in Example 1 was changed from 1.33 g (0.35% by weight of acrylic acid) to 0.19 g (0.05% by weight of acrylic acid), and the amount of pentaerythritol triallyl ether charged. From 0.49 g (0.13% by weight of acrylic acid) to 0.19 g (0.05% by weight of acrylic acid), and the amount of 2-iodo-2-methylpropionitrile charged from 0.055 g to 0. An additive (G-16) for the negative electrode of the alkaline battery of the present invention was obtained in the same manner as in Example 1 except that the amount was replaced with 110 g.

<Example 17>
The amount of trimethylolpropane triacrylate of Example 1 charged from 1.33 g (0.35% by weight of acrylic acid) to 3.80 g (1.00% by weight of acrylic acid), and the amount of pentaerythritol triallyl ether charged. From 0.49 g (0.13% by weight of acrylic acid) to 0.76 g (0.20% by weight of acrylic acid), and the amount of 2-iodo-2-methylpropionitrile charged from 0.055 g to 0. An additive (G-17) for the negative electrode of the alkaline battery of the present invention was obtained in the same manner as in Example 1 except that the amount was replaced with 110 g.

<Example 18>
The amount of trimethylolpropane triacrylate of Example 1 charged was changed from 1.33 g (0.35% by weight of acrylic acid) to 3.80 g (1.00% by weight of acrylic acid), and the amount of pentaerythritol triallyl ether charged. From 0.49 g (0.13% by weight of acrylic acid) to 3.80 g (1.00% by weight of acrylic acid), and the amount of 2-iodo-2-methylpropionitrile charged from 0.055 g to 0. An additive (G-18) for the negative electrode of the alkaline battery of the present invention was obtained in the same manner as in Example 1 except that the amount was replaced with 110 g.

<Example 19>
The amount of trimethylolpropan triacrylate charged in Example 1 was changed from 1.33 g (0.35% by weight of acrylic acid) to 0.95 g (0.25% by weight of acrylic acid), and the amount of pentaerythritol triallyl ether charged. From 0.49 g (0.13% by weight of acrylic acid) to 0.19 g (0.05% by weight of acrylic acid), and the amount of 2-iodo-2-methylpropionitrile charged from 0.055 g to 0. An additive (G-19) for the negative electrode of the alkaline battery of the present invention was obtained in the same manner as in Example 1 except that the amount was replaced with 110 g.

<Example 20>
The amount of trimethylolpropane triacrylate of Example 1 charged from 1.33 g (0.35% by weight of acrylic acid) to 0.95 g (0.25% by weight of acrylic acid), and the amount of pentaerythritol triallyl ether charged. Was changed from 0.49 g (0.13% by weight of acrylic acid) to 0.26 g (0.07% by weight of acrylic acid) in the same manner as in Example 1 and added to the negative electrode of the alkaline battery of the present invention. The agent (G-20) was obtained.

<Example 21>
The amount of trimethylolpropan triacrylate charged in Example 1 was changed from 1.33 g (0.35% by weight of acrylic acid) to 0.95 g (0.25% by weight of acrylic acid), and the amount of pentaerythritol triallyl ether charged. From 0.49 g (0.13% by weight of acrylic acid) to 0.26 g (0.07% by weight of acrylic acid), and the amount of 2-iodo-2-methylpropionitrile charged from 0.055 g to 0. An additive (G-21) for the negative electrode of the alkaline battery of the present invention was obtained in the same manner as in Example 1 except that the amount was replaced with 028 g.

<Comparative example 1>
460.0 g of acrylic acid, 1.15 g of pentaerythritol triaryl ether (0.25 wt% of acrylic acid), 0.92 g of trimethylolpropane triacrylate (0.20 wt% of acrylic acid) in a 3 liter adiabatic polymerization tank. ) And 1600 g of ion-exchanged water were added and mixed by stirring to prepare an acrylic acid aqueous solution, and then the acrylic acid aqueous solution was cooled to 3 ° C. After cooling, nitrogen was aerated in the acrylic acid aqueous solution at a flow rate of 5 L / min to bring the dissolved oxygen concentration in the acrylic acid aqueous solution to 0.10 ppm or less. After confirming that the aqueous acrylic acid solution was at 3 ° C., 2,2'-azobis (2-amidinopropane) hydrochloride (sum) having a concentration of 10% by weight was used as a polymerization initiator in an adiabatic polymerization tank while continuing nitrogen aeration. Kojunyaku Kogyo Co., Ltd., trade name: V-50) aqueous solution 13.8 g, concentration 1.0% by weight hydrogen peroxide solution 1.38 g, concentration 1.0% by weight L-ascorbic acid aqueous solution 1.38 g, 0.68 g of an aqueous solution of iron (III) sulfate having a concentration of 0.1% by weight was added. After the addition of the polymerization initiator, nitrogen aeration was continued for 25 minutes, nitrogen aeration was stopped, and the mixture was allowed to stand for 16 hours to carry out the polymerization reaction. After allowing to stand for 16 hours, the hydrogel obtained by the polymerization reaction was taken out from the polymerization reaction tank.
The water-containing gel taken out was subdivided into a noodle shape with a thickness of 3 to 10 mm using a small meat chopper (manufactured by Royal), and a 49 wt% sodium hydroxide (special grade reagent) aqueous solution was added to the subdivided water-containing gel. After adding 169 g, the water-containing gel was uniformly kneaded and neutralized using the small meat chopper.
The neutralized hydrogel was laminated on a SUS screen with an opening of 850 μm to a thickness of 5 cm, and hot air at 150 ° C was blown for 1 hour using a small air-permeable dryer (manufactured by Inoue Metal Co., Ltd.). The water in the hydrogel was evaporated to obtain a dry gel.
After crushing the dried gel with a cooking mixer, a sieve having a mesh size of 45 μm (330 mesh) was used to collect particles having a particle size of 45 μm or less to obtain an additive (H-1) for the negative electrode of an alkaline battery. ..

<Comparative example 2>
The dried gel obtained in Comparative Example 1 is pulverized using a cooking mixer, and then added to the negative electrode of an alkaline battery by collecting particles having a particle size of 150 μm or less using a sieve having a mesh size of 150 μm (100 mesh). The agent (H-2) was obtained.

<Comparative example 3>
The dried gel obtained in Comparative Example 1 is pulverized using a cooking mixer, and then added to the negative electrode of an alkaline battery by collecting a particle having a particle size of 250 μm or less using a sieve having a mesh size of 250 μm (60 mesh). The agent (H-3) was obtained.

<Comparative example 4>
The dried gel obtained in Comparative Example 1 is pulverized using a cooking mixer, and then added to the negative electrode of an alkaline battery by collecting particles having a particle size of 600 μm or less using a sieve having a mesh size of 600 μm (26 mesh). Agent (H-4) was obtained.

<Comparative example 5>
Same as Example 1 except that the amount of pentaerythritol triallyl ether charged in Example 1 was changed from 0.49 g (0.13% by weight of acrylic acid) to 2.26 g (0.60% by weight of acrylic acid). To obtain an additive (H-5) for the negative electrode of an alkaline battery.

<Comparative Example 6>
The amount of pentaerythritol triallyl ether charged in Example 1 was increased from 0.49 g (0.13% by weight of acrylic acid) to 2.26 g (0.60% by weight of acrylic acid), 2-iodo-2-methylpro. An additive (H-6) for the negative electrode of an alkaline battery was obtained in the same manner as in Example 1 except that the amount of pionitrile charged was changed from 0.055 g to 0.172 g.

<Comparative example 7>
Compared with Comparative Example 2 except that the amount of pentaerythritol triaryl ether charged in Comparative Example 2 was changed from 1.15 g (0.25% by weight of acrylic acid) to 2.76 g (0.60% by weight of acrylic acid). A dry gel was obtained in the same manner. After crushing the dried gel with a cooking mixer, a sieve having a mesh size of 150 μm (100 mesh) is used to collect particles having a particle size of 150 μm or less to obtain an additive (H-7) for the negative electrode of an alkaline battery. Obtained.

<Comparative Example 8>
Same as in Example 1 except that the amount of pentaerythritol triallyl ether charged in Example 1 was changed from 0.49 g (0.13% by weight of acrylic acid) to 3.02 g (0.80% by weight of acrylic acid). To obtain an additive (H-8) for the negative electrode of an alkaline battery.

<Comparative Example 9>
The amount of pentaerythritol triallyl ether charged in Example 1 was increased from 0.49 g (0.13% by weight of acrylic acid) to 3.02 g (0.80% by weight of acrylic acid), 2-iodo-2-methylpro. An additive (H-9) for the negative electrode of an alkaline battery was obtained in the same manner as in Example 1 except that the amount of pionitrile charged was changed from 0.055 g to 0.172 g.

<Comparative Example 10>
166.7 g of the negative electrode additive (H-2) for alkaline batteries and 25,000 commercially available polyacrylic acid (average molecular weight: about 25,000, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 33.3 g were charged into the kneader. After stirring for 5 minutes, the mixture was taken out to obtain an additive (H-10) for the negative electrode of an alkaline battery.

<Comparative Example 11>
166.7 g of the negative electrode additive (H-5) for alkaline batteries and 25,000 g of commercially available polyacrylic acid (average molecular weight: about 25,000, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) were charged into the kneader. After stirring for 5 minutes, the mixture was taken out to obtain an additive (H-11) for the negative electrode of an alkaline battery.

<Comparative Example 12>
166.7 g of the negative electrode additive (H-6) for alkaline batteries and 25,000 commercially available polyacrylic acid (average molecular weight: about 25,000, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 33.3 g were charged into the kneader. After stirring for 5 minutes, the mixture was taken out to obtain an additive (H-12) for the negative electrode of an alkaline battery.

<Comparative Example 13>
166.7 g of the negative electrode additive (H-7) for an alkaline battery and 33.3 g of a commercially available Carbopol 974 PNF (manufactured by Lubriso Advanced Materials. Inc) were charged into a kneader, and after stirring for 5 minutes, the mixture was taken out, and the additive for the negative electrode of an alkaline battery (made by Lubriso Advanced Materials. H-13) was obtained.

<Comparative Example 14>
166.7 g of the negative electrode additive (H-8) for an alkaline battery and 33.3 g of a commercially available Carbopol 974 PNF (manufactured by Lubriso Advanced Materials. Inc) were charged into a kneader, and after stirring for 5 minutes, the mixture was taken out, and the additive for the negative electrode of an alkaline battery (made by Lubriso Advanced Materials. H-14) was obtained.

<Comparative Example 15>
62.5 g of the negative electrode additive (H-2) for alkaline batteries and 25,000 g of commercially available polyacrylic acid (average molecular weight: about 25,000, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) were charged into the kneader. After stirring for 5 minutes, the mixture was taken out to obtain an additive (H-15) for the negative electrode of an alkaline battery.

<Comparative Example 16>
62.5 g of the negative electrode additive (H-5) for alkaline batteries and 25,000 g of commercially available polyacrylic acid (average molecular weight: about 25,000, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) were charged into the kneader. After stirring for 5 minutes, the mixture was taken out to obtain an additive (H-16) for the negative electrode of an alkaline battery.

<Comparative example 17>
62.5 g of the negative electrode additive (H-6) for alkaline batteries and 25,000 g of commercially available polyacrylic acid (average molecular weight: about 25,000, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) were charged into the kneader. After stirring for 5 minutes, the mixture was taken out to obtain an additive (H-17) for the negative electrode of an alkaline battery.

<Comparative Example 18>
Add 62.5 g of the negative electrode additive (H-7) for alkaline batteries and 137.5 g of commercially available Carbopol 974PNF (manufactured by Lubriso Advanced Materials. Inc) to the kneader, stir for 5 minutes, remove the mixture, and remove the negative electrode additive (H-7) for alkaline batteries. H-18) was obtained.

<Comparative Example 19>
Add 62.5 g of the negative electrode additive (H-8) for alkaline batteries and 137.5 g of commercially available Carbopol 974PNF (manufactured by Lubriso Advanced Materials. Inc) to the kneader, stir for 5 minutes, remove the mixture, and remove the negative electrode additive (H-8) for alkaline batteries. H-19) was obtained.

<Comparative Example 20>
Add 62.5 g of the negative electrode additive (H-9) for alkaline batteries and 137.5 g of commercially available Carbopol 974PNF (manufactured by Lubriso Advanced Materials. Inc) to the kneader, stir for 5 minutes, remove the mixture, and remove the negative electrode additive (H-9) for alkaline batteries. H-20) was obtained.

<Comparative Example 21>
Commercially available polyacrylic acid 25,000 (average molecular weight: about 25,000, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was used as a negative electrode additive (H-21) for a comparative alkaline battery.

<Comparative Example 22>
A commercially available Carbopol 974PNF (manufactured by Rubysol Advanced Materials. Inc.) was used as a negative electrode additive (H-22) for a comparative alkaline battery.

Negative electrode additives (G-1) to (G-21) for alkaline batteries manufactured in Examples 1 to 21 and negative electrode additives (H-1) for comparative alkaline batteries manufactured in Comparative Examples 1 to 22. Regarding (H-22), the volume average particle size, the amount of soluble component in physiological saline, Mw / Mn of the component having a molecular weight of 100,000 or less among the soluble components, and the gel perm obtained for the soluble component. Ratio of the area of the soluble component having a molecular weight of 100,000 or less (the ratio of the area of the soluble component in the table) to the total area of the chromatogram of the ion chromatography method, 40% by weight potassium hydroxide and the negative electrode of the alkaline battery Measure the viscosity of the mixed solution to which 2% by weight of the additive is added (in the table, the viscosity of the mixed solution), the absorption amount of the 40% by weight potassium hydroxide aqueous solution (absorption amount in the table), and the liquid separation rate by the above-mentioned method. The results are shown in Tables 1 and 2 (Examples) and Tables 3 to 4 (Comparative Examples) together with the ratio of the cross-linking agent used as the negative electrode additive of the alkaline battery and the degree of neutralization.

From Tables 1 to 4, the additives for the negative electrode of the alkaline battery of the present invention are 40% by weight potassium hydroxide aqueous solution absorption amount, 40% by weight potassium hydroxide aqueous solution and the negative electrode additive of the alkaline battery (compared to the comparative ones). It can be seen that the viscosity and the release rate of the mixed solution to which 2% by weight of G) is added are excellent.
From this, the additive for the negative electrode of the alkaline battery of the present invention imparts sufficient viscosity to the negative electrode material without using a material having a thickening function such as polyacrylic acid, and is suitable for workability for injecting the negative electrode material. Can be given, and variations in the injection time and the injection amount at the time of filling the negative electrode material become suitable. Furthermore, the impact resistance of the battery can be improved by preventing the precipitation of zinc. In addition, since the absorption amount of the 40% potassium hydroxide aqueous solution is in a suitable range, excessive separation of the alkaline electrolytic solution can be prevented, so that the battery duration after long-term storage is maintained, and the long-term discharge characteristics of the battery are maintained. It can be said that it is excellent. Since it is not necessary to use a material having a thickening function, it is possible to reduce the process of dissolving and homogenizing the material having a thickening function, and it can be said that the cost and work efficiency are excellent.

Further, zinc powder is used by using the negative electrode additives (G-1) to (G-21) of the alkaline battery of the present invention and the negative electrode additives (H-1) to (H-22) of the comparative alkaline battery. Tables 5 to 6 show the results of measuring the sedimentation property, the variation in injection time and injection amount, the battery duration and the impact resistance by the following methods.

(1) Precipitation of zinc powder In a biaxial kneader (manufactured by Irie Trading Co., Ltd., product name: PNV-1) with a capacity of 1 liter, 150 g of a 33 wt% potassium hydroxide aqueous solution and zinc powder having a volume average particle diameter of 200 μm (UNION MINIERES) A. A.) 300 g and 3.0 g of an additive for the negative electrode of an alkaline battery were added and mixed at a rotation speed of 50 rpm for 60 minutes to prepare a negative electrode material. 50 g of the prepared negative electrode material was placed in a sample bottle (diameter 34 mm, height 77 mm, made of polypropylene) having a sealable capacity of 50 ml, and the bubbles entered during mixing were defoamed under reduced pressure.
After sealing the sample bottle and leaving it in a constant temperature bath at 40 ° C for 30 days, use the device attached to the powder tester (manufactured by Hosokawa Micron Co., Ltd.) to measure the sample bottle 300 times from a height of 3 cm at a rate of 30 times / min. Tapping was promoted to settle the zinc powder. After the tapping is completed, the most sedimented distance (mm) of the zinc powder is measured from the initial position of the zinc powder (the position of the upper end of the negative electrode material in the sample bottle), and this is the sedimentation property (mm) of the zinc powder. And said.

(2) Variation in injection time and injection amount In a biaxial kneader with a capacity of 1 liter, 150 g of 33 wt% potassium hydroxide aqueous solution, 300 g of zinc powder (manufactured by UNION MINIERES.A.) having a volume average particle diameter of 200 μm, and an alkaline battery 3.0 g of an additive for a negative electrode was added and mixed at a rotation speed of 50 rpm for 60 minutes to prepare a negative electrode material. The prepared negative electrode material was transferred to a beaker, and the bubbles that entered during mixing were defoamed under reduced pressure. The defoamed negative electrode material was sucked into a 10 ml syringe having an inner diameter of 2 mm and a scale of 0.1 ml unit.
From the height of the mouth of a 5 ml sample bottle (inner diameter 18 mm, height 40 mm), push the syringe by 5.0 ml to inject the negative electrode material into the sample bottle, and from the time when the pushing of the syringe is completed, the negative electrode from the syringe inlet. The time (seconds) until the material was completely separated was measured with a stopwatch. The same operation was repeated 20 times in total, and the arithmetic mean value was taken as the injection time (seconds).
The weight of the negative electrode gel injected into the sample bottle (20 times each) was measured, and the standard deviation (σ) of the injection amount was calculated to obtain the variation in the injection amount.

(3) Battery duration In a biaxial kneader with a capacity of 1 liter, 150 g of a 33 wt% potassium hydroxide aqueous solution, 300 g of zinc powder (manufactured by UNION MINIERES.A.) having a volume average particle diameter of 200 μm, and a negative electrode of an alkaline battery. 3.0 g of the additive for use is added and mixed at 50 rpm for 60 minutes to prepare a negative electrode material, and after defoaming under reduced pressure, 15 g of this negative electrode material is placed in the negative electrode container of the LR-6 type model battery. A model battery was prepared by injecting into.
As the constituent materials of each part other than the negative electrode material of the model battery, the material of the shrink tube is polyethylene, the material of the positive electrode material is 50 parts by weight of electrolytic manganese dioxide, 5 parts by weight of acetylene black, and 40% by weight of potassium hydroxide. A compound consisting of 1 part by weight of an aqueous solution, a nickel-plated steel plate as the material of the outer can, a polyolefin as the material of the separator, a tin-plated brass rod as the material of the current collector rod, a polyolefin resin as the material of the gasket, and a negative electrode. A nickel-plated steel plate was used as the material of the terminal plate.
An external resistor of 2Ω was connected to the produced model battery at room temperature (20 to 25 ° C.), and the battery was continuously discharged, and the time until the voltage dropped to 0.9V was defined as the battery duration (hour).
After producing the model battery, the same operation was performed on the model battery that had been allowed to stand in a constant temperature bath at 80 ° C. for 15 days, and the battery duration was measured.

(4) Impact resistance of the battery While connecting a 2Ω external resistor at room temperature (20 to 25 ° C) to the model battery manufactured in the same manner as above and continuously discharging the model battery, the model battery is placed on wood from a height of 1 m. The battery was dropped 10 times in a row, the voltage before the first drop and the voltage immediately after the 10th drop were measured, and the impact resistance (%) was calculated by the following formula.
Impact resistance (%) = {voltage immediately after the 10th drop (V) / voltage before the first drop (V)} x 100
After producing the model battery, the same operation was performed on the model battery that had been allowed to stand in a constant temperature bath at 80 ° C. for 15 days, and the impact resistance was determined.

From Tables 5 to 6, the additives for the negative electrode of the alkaline battery of the present invention are excellent in the sedimentation property of zinc powder, the variation of injection time and injection amount, the duration of the battery and the impact resistance as compared with those of the comparative example. You can see that there is.

The negative electrode additive (G) for the alkaline battery of the present invention is not only a cylindrical alkaline battery, but also a negative electrode for primary and secondary alkaline batteries such as alkaline button batteries, silver oxide batteries, nickel-cadmium storage batteries, and nickel-hydrogen storage batteries. It is also useful as an additive. Further, the alkaline battery using the negative electrode additive of the alkaline battery of the present invention is useful as an alkaline battery with improved production efficiency because it has excellent impact resistance, excellent discharge characteristics, and excellent viscosity stability of the negative electrode material. Is.

Claims

It contains a water-soluble vinyl monomer (a1) and / or a vinyl monomer (a2) that becomes (a1) by hydrolysis and a cross-linked polymer (A) containing a cross-linking agent (b) as an essential constituent monomer unit. Additive for negative electrode (G) of alkaline battery satisfying 1) to (3):
(1) The amount of the soluble component of the crosslinked polymer (A) in 0.9% by weight of physiological saline is 5 to 40% by weight based on the weight of (A);
(2) Of the components soluble in 0.9% by weight of the crosslinked polymer (A) in physiological saline, the number average molecular weight (Mn) of the components having a molecular weight of 100,000 or less, which are all determined by the following methods. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the amount of the crosslinked polymer (A) was 4.0 to 6.0, and the gel permeation chromatograph obtained with respect to the soluble component of the crosslinked polymer (A) in physiological saline was obtained. The ratio of the area of the soluble component having a molecular weight of 100,000 or less to the total area of the chromatogram of the imaging method is 50% or less;
Method:
Obtained by obtaining a chromatogram by gel permeation chromatography and calculating the proportions of Mw, Mn, and area in compartments having a molecular weight of 100,000 or less;
(3) The viscosity of a mixed solution prepared by adding 2% by weight of the negative electrode additive (G) for an alkaline battery to a 40% by weight aqueous potassium hydroxide solution at 25 ° C. is 10 to 60 Pa · s.
The additive for the negative electrode of an alkaline battery according to claim 1, wherein the absorption amount of a 40 wt% potassium hydroxide aqueous solution is 40 to 70 g / g.
The cross-linking agent (b) is composed of a cross-linking agent (b1) that hydrolyzes with an alkali and a cross-linking agent (b2) that does not hydrolyze with an alkali, and the amounts of the cross-linking agent (b1) and the cross-linking agent (b2) are independent. Then, it is 0.05 to 1% by weight based on the total weight of the water-soluble vinyl monomer (a1) and the vinyl monomer (a2), and the weight ratio of (b1) to (b2) [(b1) / (b2)). ] Is 1 to 5, the additive for the negative electrode of the alkaline battery according to claim 1 or 2.
100 parts by weight of a 40% by weight aqueous potassium hydroxide solution, 2 parts by weight of the negative additive (G) for an alkaline battery and 200 parts by weight of zinc powder were stirred and mixed until uniform, and the mixture was allowed to stand at 25 ° C. for 168 hours. The additive for a negative electrode of an alkaline battery according to any one of claims 1 to 3, wherein the liquid separation rate is 10% by weight or less.
An alkaline battery containing the additive for the negative electrode of the alkaline battery according to any one of claims 1 to 4 and zinc powder and / or zinc alloy powder as the negative electrode material.