【発明の詳細な説明】[Detailed description of the invention]
（発明の分野）
本発明は亜鉛アルカリ電池に関し、詳しくは鉛
とアルミニウムおよび／またはカドミウムとビス
マス、カルシウム、テルルより選ばれる１種以上
を特定範囲で含有した亜鉛合金をそのまま、もし
くは汞化して電池用負極活物質として用いた亜鉛
アルカリ電池に関する。
（発明の背景）
亜鉛を負極活物質として用いたアルカリ電池等
においては、水酸化カリウム水溶液等の強アルカ
リ性電解液を用いるため、電池を密閉しなければ
ならない。この電池の密閉は電池の小型化を図る
際には特に重要であるが、同時に電池保存中の亜
鉛の腐食により発生する水素ガスを閉じ込めるこ
とになる。従つて長期保存中に電池内部のガス圧
が高まり、密閉が完全なほど爆発等の危険が伴な
う。
その対策として、負極活物質である亜鉛の腐食
を防止して、電池内部の水素ガス発生を少なくす
ることが研究され、水銀の水素過電圧を利用した
汞化亜鉛を負極活物質として用いることが専ら行
なわれている。このため、今日市販されているア
ルカリ電池の負極活物質は５〜10重量％程度の多
量の水銀を含有しており、社会的ニーズとして、
より低水銀のもの、あるいは無水銀の電池の開発
が強く期待されるようになつてきた。
そこで、電池内の水銀含有量を低減させるべ
く、亜鉛に各種金属を添加した亜鉛合金粉末に関
する提案が種々なされている。例えば、亜鉛に鉛
を添加した亜鉛合金粉末、あるいは本発明者等に
よる亜鉛に鉛とインジウムを添加した亜鉛合金粉
末（特開昭58−181266号公報）等がある。しか
し、これらの亜鉛合金粉末はある程度のガス発生
抑制効果を奏するが、まだ十分とは言えない。例
えば亜鉛に鉛とインジウムを添加した亜鉛合金粉
末についてはこれを水銀含有率１重量％程度の低
汞化とした場合、ガス発生試験の初期においては
非常にガス発生が抑制されているが、長期間とな
ると次第にガス発生速度（ml／ｇ・day）が増大
する傾向が見られた。
このように、負極活物質である亜鉛合金粉末を
低汞化としつつ、水素ガス発生量を低減し、しか
も電池性能である放電性能を高い水準に維持する
電池は未だ得られていない。
（発明の目的）
本発明はかかる現状に鑑み、水銀の含有率を著
しく減少させつつ、水素ガス発生を抑制し、しか
も放電性能を高い水準に維持する負極活物質を用
いた亜鉛アルカリ電池を提供することを目的とす
る。
（発明の経緯）
本発明者らはこの目的に沿つて鋭意研究の結
果、亜鉛からなる負極活物質において、鉛とアル
ミニウムおよび／またはカドミウムとビスマス、
カルシウム、テルルより選ばれる１種以上とを特
定範囲の量添加することにより、これら添加元素
の相乗的な効果によつて、従来の低汞化した亜鉛
合金粉末よりも更に水素ガス発生量を低下させ、
しかも放電性能に優れた亜鉛アルカリ電池が得ら
れることを見出し本発明に到達した。
（発明の構成）
すなわち本発明は、鉛を0.01〜0.5重量％、ア
ルミニウムおよび／またはカドミウムを0.005〜
0.5重量％、ビスマス、カルシウム、テルルより
選ばれる１種以上を合計0.005〜0.5重量％と、残
部が亜鉛からなる亜鉛合金を負極活物質として用
いたことを特徴とする亜鉛アルカリ電池にある。
本発明において、鉛とアルミニウムおよび／ま
たはカドミウムとビスマス、カルシウム、テルル
より選ばれる１種以上を特定量添加した亜鉛合金
は、そのまま負極活物質として用いるか、亜鉛合
金を汞化した後に負極活物質として用いる。汞化
する場合の水銀含有率は、従来の負極活物質の水
銀含有率よりも少ない量、すなわち5.0重量％未
満であるが、より汞化率を低くし、低公害性を考
慮すると3.0重量％以下である。また、1.0重量％
前後またはそれ以下の少量であつてもガス発生を
抑制することが可能である。特に、排気機構を備
えた空気電池や水素吸収機構を備えた亜鉛アルカ
リ電池等においては、水素ガスの発生許容量は比
較的大きいので、このような電池に本発明を適用
する場合は、1.0重量％以下の低汞化率または無
汞化の亜鉛合金が負極活物質として好ましく用い
られる。
この負極活物質に用いられる亜鉛合金の鉛の含
有率は0.01〜0.5重量％、アルミニウムおよび／
またはカドミウムの含有率は0.005〜0.5重量％、
ビスマス、カルシウム、テルルより選ばれる１種
以上の含有率は0.005〜0.5重量％と少量で添加効
果が発揮される。鉛とアルミニウムおよび／また
はカドミウムとビスマス、カルシウム、テルルよ
り選ばれる１種以上の含有率がそれぞれ下限未満
では本発明の効果が得られず、上限を越えると、
不純物を含有した亜鉛のように、自己放電が進
み、ガス発生抑制および放電性能にとつて良好な
結果が得られない。なお、アルミニウムの含有率
は0.005〜0.2重量％の範囲が特に好ましく、0.2重
量％を越えた場合にはそれほどの含有効果が見ら
れない。また、カルシウムの含有率も0.005〜0.2
重量％の範囲が特に好ましく、0.2重量％を越え
た場合にはそれほどの含有効果が得られない。
このように本発明の亜鉛アルカリ電池は、電解
液に苛性カリ、苛性ソーダ等を主成分とするアル
カリ水溶液を用い、負極活物質に上記した亜鉛合
金または汞化した亜鉛合金、正極活物質に二酸化
マンガン、酸化銀、酸素等を用いることにより得
られる。
（実施例の説明）
以下、実施例および比較例に基づいて本発明を
具体的に説明する。
実施例 １〜25
純度99.997％以上の亜鉛地金を約500℃で溶融
し、これに第１表に示すごとく鉛とアルミニウム
とビスマスの含有率がそれぞれ0.05重量％となる
ように添加して亜鉛合金を作成し、これを高圧ア
ルゴンガス（噴出圧５Kg／cm2）を使つて粉体化し
た。次に水酸化カリウム10％のアルカリ性溶液中
にて上記粉末に1.0重量％になるように水銀を添
加して、汞化処理を行ない亜鉛合金粉末（実施例
１）を得た。
また、第１表に示すごとく、下記の組成で、
(1)：鉛0.05重量％、カドミウム0.05重量％、ビス
マス0.05重量％、
(2)：鉛0.05重量％、アルミニウム0.05重量％、カ
ルシウム0.05重量％、
(3)：鉛0.05重量％、アルミニウム0.05重量％、テ
ルル0.05重量％、
(4)：鉛0.05重量％、カドミウム0.05重量％、カル
シウム0.05重量％、
(5)：鉛0.05重量％、カドミウム0.05重量％、テル
ル0.05重量％、
(6)：鉛0.01重量％、アルミニウム0.01重量％、ビ
スマス0.01重量％、
(7)：鉛0.5重量％、アルミニウム0.5重量％、ビス
マス0.5重量％、
(8)：鉛0.01重量％、カドミウム0.01重量％、ビス
マス0.01重量％、
(9)：鉛0.5重量％、カドミウム0.5重量％、ビスマ
ス0.5重量％、
(10)：鉛0.01重量％、アルミニウム0.01重量％、カ
ルシウム0.01重量％、
(11)：鉛0.5重量％、アルミニウム0.5重量％、カ
ルシウム0.5重量％、
(12)：鉛0.01重量％、アルミニウム0.01重量％、
テルル0.01重量％、
(13)：鉛0.5重量％、カドミウム0.5重量％、テル
ル0.5重量％、
(14)：鉛0.01重量％、カドミウム0.01重量％、カ
ルシウム0.01重量％、
(15)：鉛0.5重量％、カドミウム0.5重量％、カル
シウム0.5重量％、
(16)：鉛0.01重量％、カドミウム0.01重量％、テ
ルル0.01重量％、
(17)：鉛0.5重量％、カドミウム0.5重量％、テル
ル0.5重量％、
(18)：鉛0.05重量％、アルミニウム0.05重量％、
ビスマス0.05重量％、カルシウム0.05重量％、
(19)：鉛0.5重量％、カドミウム0.5重量％、ビス
マス0.1重量％、カルシウム0.2重量％、テルル
0.2重量％、
(20)：鉛0.05重量％、アルミニウム0.05重量％、
カドミウム0.05重量％、ビスマス0.05重量％、
(21)：鉛0.05重量％、アルミニウム0.05重量％、
カドミウム0.05重量％、ビスマス0.05重量％、
カルシウム0.05重量％、テルル0.05重量％、
(22)：鉛0.5重量％、アルミニウム0.2重量％、ビ
スマス0.5重量％、
(23)：鉛0.5重量％、アルミニウム0.2重量％、カ
ルシウム0.2重量％、
(24)：鉛0.5重量％、アルミニウム0.2重量％、テ
ルル0.5重量％、
からなる亜鉛合金をそれぞれ作成し、これを前記
と同様な方法で粉体化し、汞化処理を行なつて水
銀含有率が1.0重量％の亜鉛合金粉体（実施例２
〜25）を得た。
このようにして得られた亜鉛合金粉体を使つて
水素ガス発生試験を行ない、その結果を第１表に
示す。なお、ガス発生試験は、電解液として濃度
40重量％の水酸化カリウム水溶液に酸加亜鉛を飽
和させたものを５mlを用い、亜鉛合金粉末を10ｇ
を用いて45℃で50日間のガス発生量（ml／ｇ）を
測定した。
また、これらの亜鉛合金粉末を負極活性物質と
して第１図に示すアルカリマンガン電池を用いて
電池性能を評価した。第１図のアルカリマンガン
電池は、正極缶１、正極２、セパレーター３、亜
鉛合金粉末をカルボキシメチルセルロースでゲル
化した負極４、負極集電体５、ゴムパツキン６、
押さえ板７で構成されている。このアルカリマン
ガン電池を用いて放電負荷４Ω、20℃の放電条件
により終止電圧0.9Vまでの放電持続時間を測定
し、従来の負極活物質を用いた後述する比較例２
の測定値を100とした指数で示した。結果を第１
表に示す。
比較例 １〜２
実施例１と同様の方法で亜鉛に鉛を0.05重量％
添加した汞化亜鉛合金粉末（比較例１）と亜鉛に
鉛を0.05重量％、インジウムを0.05重量％添加し
た汞化亜鉛合金粉末（比較例２）を得た。
これを実施例１と同様の方法で水素ガス発生試
験と電池性能試験を行ない、その結果を第１表に
示した。
(Field of the Invention) The present invention relates to a zinc-alkaline battery, and more specifically, a battery made of a zinc alloy containing lead, aluminum and/or cadmium, and one or more selected from bismuth, calcium, and tellurium within a specific range, either as it is or in the form of a starch. This invention relates to a zinc-alkaline battery used as a negative electrode active material. (Background of the Invention) In alkaline batteries and the like that use zinc as a negative electrode active material, the batteries must be sealed tightly because a strong alkaline electrolyte such as an aqueous potassium hydroxide solution is used. This sealing of the battery is particularly important when attempting to miniaturize the battery, but it also traps hydrogen gas generated due to corrosion of zinc during battery storage. Therefore, during long-term storage, the gas pressure inside the battery increases, and the more completely the battery is sealed, the greater the risk of explosion. As a countermeasure, research has been conducted to prevent corrosion of zinc, which is an active material for the negative electrode, and to reduce the generation of hydrogen gas inside the battery. It is being done. For this reason, the negative electrode active materials of alkaline batteries commercially available today contain a large amount of mercury, approximately 5 to 10% by weight.
There are strong expectations for the development of lower mercury or mercury-free batteries. Therefore, various proposals have been made regarding zinc alloy powders in which various metals are added to zinc in order to reduce the mercury content in batteries. For example, there is a zinc alloy powder made by adding lead to zinc, or a zinc alloy powder made by the present inventors by adding lead and indium to zinc (Japanese Patent Laid-Open No. 181266/1983). However, although these zinc alloy powders have a certain degree of gas generation suppressing effect, it is still not sufficient. For example, when zinc alloy powder is made by adding lead and indium to zinc and the mercury content is reduced to about 1% by weight, gas generation is extremely suppressed in the early stage of the gas generation test, but over a long period of time. There was a tendency for the gas generation rate (ml/g·day) to gradually increase over time. As described above, a battery has not yet been obtained in which the zinc alloy powder, which is the negative electrode active material, has a low resistance, reduces the amount of hydrogen gas generated, and maintains the discharge performance, which is the battery performance, at a high level. (Object of the Invention) In view of the current situation, the present invention provides a zinc-alkaline battery using a negative electrode active material that significantly reduces mercury content, suppresses hydrogen gas generation, and maintains discharge performance at a high level. The purpose is to (Background of the invention) As a result of intensive research in line with this purpose, the present inventors found that in a negative electrode active material made of zinc, lead and aluminum and/or cadmium and bismuth,
By adding one or more selected from calcium and tellurium in a specific range, the synergistic effect of these added elements reduces the amount of hydrogen gas generated even more than the conventional low-strength zinc alloy powder. let me,
Moreover, they discovered that a zinc-alkaline battery with excellent discharge performance could be obtained and arrived at the present invention. (Structure of the Invention) That is, the present invention contains 0.01 to 0.5% by weight of lead and 0.005 to 0.5% of aluminum and/or cadmium.
0.5% by weight, a total of 0.005 to 0.5% by weight of one or more selected from bismuth, calcium, and tellurium, and the balance being zinc, as a negative electrode active material. In the present invention, a zinc alloy to which a specific amount of one or more selected from lead and aluminum and/or cadmium and bismuth, calcium, and tellurium is added can be used as a negative electrode active material as is, or the zinc alloy can be used as a negative electrode active material after being made into a liquid. used as The mercury content when converted into water is lower than the mercury content of conventional negative electrode active materials, that is, less than 5.0% by weight, but if the mercury content is lowered and low pollution is considered, it is 3.0% by weight. It is as follows. Also, 1.0% by weight
It is possible to suppress gas generation even if the amount is around or below. In particular, in air batteries equipped with an exhaust mechanism or zinc-alkaline batteries equipped with a hydrogen absorption mechanism, the hydrogen gas generation capacity is relatively large, so when applying the present invention to such batteries, 1.0 weight Zinc alloys with a low or non-grading rate of less than 10% are preferably used as the negative electrode active material. The lead content of the zinc alloy used in this negative electrode active material is 0.01 to 0.5% by weight, aluminum and/or
Or cadmium content is 0.005-0.5% by weight,
The content of one or more selected from bismuth, calcium, and tellurium is as small as 0.005 to 0.5% by weight, and the effect of addition is exhibited. If the content of one or more selected from lead and aluminum and/or cadmium and bismuth, calcium, and tellurium is less than the lower limit, the effect of the present invention cannot be obtained, and if the content exceeds the upper limit,
Like zinc containing impurities, self-discharge progresses and good results cannot be obtained in terms of gas generation suppression and discharge performance. Note that the content of aluminum is particularly preferably in the range of 0.005 to 0.2% by weight, and if it exceeds 0.2% by weight, no significant effect will be seen. In addition, the calcium content is 0.005 to 0.2
A range of % by weight is particularly preferable, and if it exceeds 0.2% by weight, no significant effect will be obtained. As described above, the zinc-alkaline battery of the present invention uses an alkaline aqueous solution containing caustic potash, caustic soda, etc. as the main component as an electrolyte, the above-mentioned zinc alloy or aqueous zinc alloy as a negative electrode active material, and manganese dioxide, as a positive electrode active material, Obtained by using silver oxide, oxygen, etc. (Description of Examples) The present invention will be specifically described below based on Examples and Comparative Examples. Examples 1 to 25 Zinc ingot with a purity of 99.997% or higher is melted at about 500°C, and lead, aluminum, and bismuth are added to the melt at a content of 0.05% by weight each as shown in Table 1 to form zinc. An alloy was prepared and pulverized using high pressure argon gas (ejection pressure 5 Kg/cm 2 ). Next, mercury was added to the above powder to give a concentration of 1.0% by weight in an alkaline solution containing 10% potassium hydroxide, and a hydrochloric treatment was performed to obtain a zinc alloy powder (Example 1). In addition, as shown in Table 1, with the following composition: (1): 0.05% by weight of lead, 0.05% by weight of cadmium, 0.05% by weight of bismuth, (2): 0.05% by weight of lead, 0.05% by weight of aluminum, 0.05% by weight of calcium. %, (3): 0.05% by weight of lead, 0.05% by weight of aluminum, 0.05% by weight of tellurium, (4): 0.05% by weight of lead, 0.05% by weight of cadmium, 0.05% by weight of calcium, (5): 0.05% by weight of lead, cadmium 0.05% by weight, Tellurium 0.05% by weight, (6): 0.01% by weight of lead, 0.01% by weight of aluminum, 0.01% by weight of bismuth, (7): 0.5% by weight of lead, 0.5% by weight of aluminum, 0.5% by weight of bismuth, (8) : 0.01% by weight of lead, 0.01% by weight of cadmium, 0.01% by weight of bismuth, (9): 0.5% by weight of lead, 0.5% by weight of cadmium, 0.5% by weight of bismuth, (10): 0.01% by weight of lead, 0.01% by weight of aluminum, calcium 0.01% by weight, (11): 0.5% by weight of lead, 0.5% by weight of aluminum, 0.5% by weight of calcium, (12): 0.01% by weight of lead, 0.01% by weight of aluminum,
Tellurium 0.01% by weight, (13): Lead 0.5% by weight, Cadmium 0.5% by weight, Tellurium 0.5% by weight, (14): Lead 0.01% by weight, Cadmium 0.01% by weight, Calcium 0.01% by weight, (15): Lead 0.5% by weight %, cadmium 0.5% by weight, calcium 0.5% by weight, (16): lead 0.01% by weight, cadmium 0.01% by weight, tellurium 0.01% by weight, (17): lead 0.5% by weight, cadmium 0.5% by weight, tellurium 0.5% by weight, (18): Lead 0.05% by weight, aluminum 0.05% by weight,
Bismuth 0.05% by weight, Calcium 0.05% by weight, (19): Lead 0.5% by weight, Cadmium 0.5% by weight, Bismuth 0.1% by weight, Calcium 0.2% by weight, Tellurium
0.2% by weight, (20): 0.05% by weight of lead, 0.05% by weight of aluminum,
Cadmium 0.05% by weight, Bismuth 0.05% by weight, (21): Lead 0.05% by weight, Aluminum 0.05% by weight,
Cadmium 0.05% by weight, bismuth 0.05% by weight,
Calcium 0.05% by weight, Tellurium 0.05% by weight, (22): Lead 0.5% by weight, Aluminum 0.2% by weight, Bismuth 0.5% by weight, (23): Lead 0.5% by weight, Aluminum 0.2% by weight, Calcium 0.2% by weight, (24) ): Create a zinc alloy consisting of 0.5% by weight of lead, 0.2% by weight of aluminum, and 0.5% by weight of tellurium, powder it in the same manner as above, and perform a filtration treatment to reduce the mercury content to 1.0%. Weight% zinc alloy powder (Example 2
~25) was obtained. A hydrogen gas generation test was conducted using the zinc alloy powder thus obtained, and the results are shown in Table 1. In addition, in the gas generation test, the concentration of electrolyte was
Using 5 ml of 40% by weight potassium hydroxide aqueous solution saturated with zinc acid, add 10 g of zinc alloy powder.
The amount of gas generated (ml/g) was measured at 45°C for 50 days using the following. Further, battery performance was evaluated using an alkaline manganese battery shown in FIG. 1 using these zinc alloy powders as a negative electrode active material. The alkaline manganese battery shown in FIG. 1 includes a positive electrode can 1, a positive electrode 2, a separator 3, a negative electrode 4 made of zinc alloy powder gelled with carboxymethyl cellulose, a negative electrode current collector 5, a rubber packing 6,
It is composed of a holding plate 7. Using this alkaline manganese battery, the discharge duration up to the final voltage of 0.9V was measured under the discharge conditions of 4Ω discharge load and 20°C, and Comparative Example 2 described below using a conventional negative electrode active material
It is expressed as an index with the measured value as 100. Results first
Shown in the table. Comparative Examples 1-2 0.05% by weight of lead in zinc using the same method as in Example 1
A zinc chloride alloy powder (Comparative Example 1) and a zinc chloride alloy powder (Comparative Example 2) in which 0.05% by weight of lead and 0.05% by weight of indium were added to zinc were obtained. This was subjected to a hydrogen gas generation test and a battery performance test in the same manner as in Example 1, and the results are shown in Table 1.
【表】
第１表に示されるごとく、亜鉛に鉛とアルミニ
ウムおよび／またはカドミウムとビスマス、カル
シウム、テルルより選ばれる１種以上を特定量添
加して汞化させた汞化亜鉛合金粉末を負極活物質
に用いた実施例１〜25は、亜鉛に鉛を添加した汞
化亜鉛合金粉末を負極活物質に用いた比較例１や
亜鉛に鉛とインジウムを添加した汞化亜鉛合金粉
末を負極活物質に用いた比較例２に比べて、水素
ガス発生抑制効果が大きく、放電性能も優れてい
ることがわかる。
（発明の効果）
以上説明のごとく、鉛とアルミニウムおよび／
またはカドミウムとビスマス、カルシウム、テル
ルより選ばれる１種以上を特定範囲で含有した亜
鉛合金をそのまま、もしくは汞化して負極活物質
として用いた本発明の亜鉛アルカリ電池は、水素
ガス発生率を抑制しつつ、電池性能を向上させる
ことが可能であり、また水銀が低含有率もしくは
含有しないことから、社会的ニーズにも沿つたも
のである。従つて、本発明の亜鉛アルカリ電池は
広範な用途に使用可能である。[Table] As shown in Table 1, a zinc chloride alloy powder made by adding specific amounts of lead, aluminum and/or cadmium, and one or more selected from bismuth, calcium, and tellurium to zinc is used as a negative electrode. Examples 1 to 25 using materials include Comparative Example 1 in which a zinc chloride alloy powder in which lead was added to zinc was used as the negative electrode active material, and Comparative Example 1 in which a zinc hydride alloy powder in which lead and indium were added to zinc was used as the negative electrode active material. It can be seen that the effect of suppressing hydrogen gas generation is greater and the discharge performance is also better than that of Comparative Example 2 used in Comparative Example 2. (Effect of the invention) As explained above, lead, aluminum and/or
Alternatively, the zinc-alkaline battery of the present invention uses a zinc alloy containing one or more selected from cadmium, bismuth, calcium, and tellurium in a specific range as a negative electrode active material, either as it is or in the form of aqueous solution, which suppresses the hydrogen gas generation rate. At the same time, it is possible to improve battery performance, and because it contains low or no mercury, it also meets social needs. Therefore, the zinc-alkaline battery of the present invention can be used in a wide range of applications.
【図面の簡単な説明】[Brief explanation of drawings]
第１図は本発明に係わるアルカリマンガン電池
の断面図を示す。
１：正極缶、２：正極、３：セパレーター、
４：負極、５：負極集電体、６：ゴムパツキン、
７：押さえ板。
FIG. 1 shows a sectional view of an alkaline manganese battery according to the present invention. 1: positive electrode can, 2: positive electrode, 3: separator,
4: Negative electrode, 5: Negative electrode current collector, 6: Rubber packing,
7: Pressing board.