JPH09306461A - Manganese dry battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manganese dry battery decreasing dispersion of battery performance by eliminating slurry viscosity change of a paste fluid and decreasing dispersion of a paste agent applied amount. SOLUTION: In a manganese dry battery with non-additive mercury and cadmium, as a dispersion medium of paste fluid applied to a separator 2, methyl alcohol or ethyl alcohol or mixed alcohole of both the alcohols is used, by using the separator 2 applying gelatinization dry processing the paste fluid containing this dispersion medium to a kraft base material surface, slurry viscosity change of paste fluid is decreased, dispersion of a paste agent applied amount can be decreased, dispersion of battery performance can be also decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manganese dry battery, and more particularly to a manganese dry battery containing no added mercury / cadmium, which has an improved paste solution applied to a separator.

[0002]

2. Description of the Related Art A manganese dry battery is generally of a paper lined type in which a separator (isolation layer) is arranged between a positive electrode mixture and a negative electrode zinc can. Such a separator plays a role of smoothly advancing an electrochemical reaction by applying a sizing agent on the side in contact with the negative electrode zinc can and sufficiently holding the electrolytic solution.

Conventionally, modified starch has been mainly used as a sizing agent, and polyvinyl alcohol, carboxymethyl cellulose, or chloride of polyacrylic acid is usually used as a binder with a separator. Kraft paper is generally used as the separator.

[0004]

When a sizing agent is applied to a separator, the sizing liquid slurry is applied and then dried to obtain a separator. , Which caused variations in battery performance. Further, increasing the electrolytic solution holding capacity of the sizing agent is an effective and reliable means for improving the battery performance, but using a sizing agent having a large electrolytic solution absorbing property increases the slurry viscosity. , It was not practical because the workability deteriorates.

The present invention has been made in view of the above situation, and an object thereof is to eliminate variations in the viscosity of the slurry of the paste solution and to reduce variations in the amount of the paste applied, thereby reducing variations in battery performance. An object of the present invention is to provide a manganese dry battery containing no cadmium.

[0006]

In order to achieve the above object, the manganese dry battery according to claim 1 of the present invention comprises methyl alcohol or ethyl alcohol or a mixture of both as a dispersion medium of a paste liquid applied to a dry battery separator. It is characterized in that a paste liquid containing the dispersion medium is applied to the surface of the kraft substrate using alcohol, and the separator is gelatinized and dried.

According to a second aspect of the present invention, in the manganese dry battery according to the first aspect, the kraft substrate has an absolute dry density of 0.6.
It is characterized by being 0 g / cm ³ or more. According to a third aspect of the present invention, in the manganese dry battery according to the second aspect, the alcohol concentration used in the dispersion medium of the paste solution is in the range of 5 to 40 mass% with respect to the dispersion liquid.

According to a fourth aspect of the present invention, in the manganese dry battery according to the third aspect, the main material of the paste solution is a crosslinked etherified cornstarch and a 6% Brabender viscograph 10
It is characterized in that the material has a BU temperature of 60 ° C. or lower.

According to a fifth aspect of the present invention, in the manganese dry battery according to the fourth aspect, the crosslinking agent for the crosslinked etherified cornstarch is phosphoric acid crosslinking with phosphorus oxychloride or trimetaphosphoric acid, crosslinking with epichlorohydrin, or both, and an ether. It is characterized in that propylene oxide is used as the agent.

According to a sixth aspect of the present invention, in the manganese dry battery according to the fifth aspect, a modified guar gum having a putrefaction-preventing anti-corrosion treatment is blended in an amount of 42% by mass or less with respect to the crosslinked etherified corn starch as the main material. It is characterized by being

Next, the operation of the present invention will be described. In the present invention, methyl alcohol, ethyl alcohol, or an alcohol mixture thereof is used as the dispersion medium. Such an alcohol dispersion medium can stabilize the slurry viscosity of the paste solution by suppressing the swelling of the paste agent, and can be uniformly applied to the isolation layer. Also,
The material used for the isolation layer is kraft paper with an absolute dry density of 0.6.
It is preferably 0 g / cm ³ or more. When it is less than 0.60, the sizing agent may penetrate into the kraft paper to cause roughness on the sizing agent surface of the obtained separator, which is not preferable for a battery. Although the alcohol concentration needs to be adjusted depending on the sizing agent used, it does not have to exceed 40% by mass with respect to the dispersion liquid. If it exceeds 40% by mass,
It is not preferable because it increases the volatility and makes it difficult to work and also increases the manufacturing cost. If it is less than 5% by mass, the effect cannot be obtained. Furthermore, the chemical guar gum content is 42.86% by mass based on the crosslinked etherified corn starch.
It is also possible to add more than the above amount by increasing the concentration of alcohol, but it is not preferable because the remarkable effect on the battery performance cannot be obtained and the manufacturing cost increases. Methyl alcohol is dangerous if accidentally ingested, but has a lower price than ethyl alcohol.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. FIG. 1 is a sectional view of one embodiment of the present invention. In the figure, 1 is a negative electrode zinc tube, and this zinc tube 1
A separator 2 to be described later is arranged inside the so as to contact the zinc can 1. Inside the separator 2 is a carbon rod 4
Is filled in the center with the positive electrode mixture 3. The positive electrode mixture 3 is composed of a molded body obtained by mixing manganese dioxide, a conductive agent such as acetylene black, and an electrolytic solution containing zinc chloride as a main component. 5 is a plastic sealing body, and the carbon rod 4 is inserted in the central through hole. Reference numeral 6 is a metal positive electrode terminal plate fitted on the top of the carbon rod 4, and 7 is a metal negative electrode terminal plate abutting on the outer peripheral portion of the zinc can 1. Reference numeral 8 is a heat-shrinkable and flexible poly-insulating tube that encloses the outer peripheral wall of the zinc can, and 9 is a metal outer can that is bent at the upper and lower ends inward to seal the entire dry battery. 10 is a sealant.

The separator 2 used in the manganese dry battery of the present invention is a product in which 20 parts by mass of polyvinyl alcohol and 6% of crosslinked etherified cornstarch at 10 BU are 60.0 ° C. and 55.0 ° C. 150 parts by mass of the mixture of guar gum according to Example 1 (however, the maximum content of guar gum is 42.86% by mass of crosslinked etherified corn starch), and 200 parts by mass of water + alcohol according to Example 1 are blended. After being applied to the craft base material, it was dried to obtain a separator 2. An R20 (single) type mercury-cadmium-free manganese dry battery was prepared using these, and used as an example.

Next, as a comparative example, the same as the example except that the alcohol concentration deviates from the range of the example or the density of the kraft base material is less than the range of the example and the one shown in the comparative example is used. Various operations were performed to prepare a R20 type mercury-free manganese dry battery.

Next, changes in the viscosity of the paste solution applied to the separator and in the mass of the applied paste after drying, which are shown in the above-mentioned Examples and Comparative Examples,
The variation was investigated. Further, the manufactured R20 type manganese battery was allowed to stand at 20 ° C. for 10 days and then at 39 Ω constant resistance for 4 days a day.
The discharge time was 0.9V and the duration was investigated. Measurement is 1
Zero measurements were performed to obtain the average value and the variation. The results are summarized in Tables 1 and 2.

[0016]

[Table 1]

[0017]

[Table 2]

The viscosity is measured by a Viscotester VT500 manufactured by HAAKE, and the sensor used is MVDI.
N was used and the shear rate was set to 75.0. In addition, the method for measuring the base material density is as follows. A test piece with a size of 1 m ² is taken and dried in an electric dryer at 105 ° C ± 3 ° C for 3 hours, and then its mass is measured. It was calculated by the following formula from Sato.

[0019]

[Equation 1]

The method for measuring the mass of the sizing agent applied after the drying treatment is as follows:
Take a test piece of 1 m ² in size and put it in an electric dryer at 105 ° C.
After drying at ± 3 ° C for 3 hours, its mass was measured and calculated from the difference between the mass and the mass of the base material before coating by the following formula. Coating mass = (base material after drying + mass of sizing agent) -base material mass before coating

The present invention is not limited to the above-mentioned examples such as the solid content in the paste solution, and it goes without saying that the matters described in the claims are covered. Further, the alcohol used in this example is deer first grade methyl alcohol manufactured by Kanto Kagaku Co., Ltd. However, it is needless to say that the same effect can be obtained with ethyl alcohol. Further, the crosslinked etherified corn starch used in this example is an etherified corn starch by phosphorus oxychloride crosslinking, but trimetaphosphoric acid crosslinking and epichlorohydrin crosslinking also achieve the same effect.

[0022]

As described above, according to the present invention,
Since it is now possible to use a sizing agent with high electrolyte absorption that could not be applied in the past, there is no change in the slurry viscosity of the sizing solution and the variation in the sizing agent application amount is reduced, which results in less variation in battery performance. It is possible to provide a manganese dry battery containing no added mercury and cadmium.

[Brief description of drawings]

FIG. 1 is a sectional view of one embodiment of the present invention.

[Explanation of symbols]

1 ... Zinc (negative electrode), 2 ... Separator, 3 ... Positive electrode mixture, 4
... carbon rod, 5 ... sealing body, 6 ... positive electrode terminal plate, 7 ... negative electrode terminal, 8 ... insulating tube, 9 ... outer can, 10 ... sealing agent.

Claims (6)

[Claims] 1. Methyl alcohol or ethyl alcohol or a mixed alcohol of both of them is used as a dispersion medium for a paste liquid applied to a dry battery separator, and the paste liquid containing the dispersion medium is applied to the surface of a kraft substrate and gelatinized and dried. A manganese dry battery characterized by using a treated separator. 2. The kraft substrate has an absolute dry density of 0.60 g /
The manganese dry battery according to claim 1, wherein the manganese dry battery is at least ³ cm ³ . 3. The manganese dry battery according to claim 2, wherein the concentration of the alcohol used in the dispersion medium of the paste solution is in the range of 5 to 40 mass% with respect to the dispersion solution. 4. A cross-linking etherified corn starch as a main material of the paste solution, and a material having a 10 BU temperature of 6% Brabender Viscograph of 60 ° C. or lower.
A manganese dry battery as described. 5. A cross-linking agent for cross-linked etherified corn starch is phosphoric acid cross-linking with phosphorus oxychloride or trimetaphosphoric acid, cross-linking with epichlorohydrin, or both, and propylene oxide is used as an etherifying agent. 4. The manganese dry battery according to 4. 6. The manganese dry battery according to claim 5, wherein the paste solution contains 42% by mass or less of a modified guar gum which is treated to prevent spoilage with respect to the main material, crosslinked etherified corn starch.