JPS5931560A - Manganese dioxide dry cell and its manufacture - Google Patents

Abstract

PURPOSE:To prevent mixture from adhering to the inner wall of a container during the process of granulation, sufficiently transmit shock and vibration to the mixture to degas it completely, equalize the diameters of granular mixture, and shorten time of granulation by adding a small amount of tetrafluoroethylene resin to make said mixture before it is granulated. CONSTITUTION:A small amount of tetrafluoroethylene resin which causes a very low friction and is excellently non-adhesive, is added to make mixture before it is granulated. As a result, the diameters of granular mixture are more equalized and its density increases, that is to say, the granular mixture is well degassed. Besides, granulation time is shortened. A positive mixture 4 prepared from such granular mixture has a notably high specific gravity, which is not less than 96% of the true spcific gravity, and is remarkably well degassed.

Description

[Detailed Description of the Invention] This invention is a paper-line type diacid, in which an anode mixture containing an electrolyte is sealed in a lead can (DIE lead can) with a separator valve. It is about the method.

Figure 1 μ is a sectional view showing the structure of such a conventional dry battery and a dry battery according to the present invention.
A cylindrical zinc can that is a cathode can, (2) is a separator made of zinc can (11, for example, Wayo), (3)
) is a cup-shaped bottom paper provided at the bottom of the zinc can (1), (4
) is a l@polar mixture sealed in a zinc can (1) via a separator (2) and a bottom paper (3), with manganese dioxide as a depolarizer and acetylene black as a conductive material.

The main component is an aqueous solution of zinc chloride and ammonium chloride as an electrolyte. (5) is the anode conductor inserted into the anode mixture (4) and the carbon rod (-), (6) is the oath paper covering the anode mixture (4), and (7) is the oath paper (6). (8) is a synthetic resin tube that covered the upper He zinc can (1); (9) is a gold sheath cap for the anode fitted to the upper end of the carbon rod (5); Ql is the metal plate for the cathode that is in contact with the bottom outer surface of the zinc can (1), (IIi & 1 synthetic resin washer 03, the metal outer can that tightens the metal cap (9) and metal plate Oe through force, θ is the metal plate) The synthetic resin provided inside the cap (9) is closed.

The conventional manufacturing method for paper-lined manganese dioxide dry batteries with such a configuration is to cover the inner circumferential surface of the zinc can (1) with a separator (2), and then place a bottom paper (
3) Load. On the other hand, as anode mixture (4).

First, about 2/3 of the required amount of Wj electrolyte is added to a mixture of electrolytic manganese dioxide, acetylene black, and finely divided zinc oxide, and the mixture is mixed to form a moist powdery mixture. This mixture 'i1. - It is aged and stored for 3 days.
P+'+j*k is made uniform and the air is allowed to escape to increase the density. After step 7, the mixture is pressure-molded to form a columnar mixture. This columnar mixture” 2 Zinc can (1)
Inner VC4? After removing the liquid, about 1/3 of the remaining 1iY is injected with the f liquid and permeated. First, a carbon rod (5) is press-fitted into the central bar 13 of the columnar mixture, and a zinc can (1) is inserted through the separator (2).
) and the anode mixture (4); a dry battery was manufactured by improving the contact strength between the battery and the anode mixture (4).
The disadvantage of r < 1 is that even after ripening, there is a considerable length t(
The remaining air completely blocks the movement of the 71R'7 liquid and ions, leading to a complete decline in performance, and expansion, cracking, and unevenness after pressure molding. The composition of the mixture used for 1cc is electric cuff c manganese dioxide (specific gravity 4
．． 4) is 50% by weight, acetylene black (specific gravity 2) is 9% by weight, and zinc oxide (specific gravity 5.5) is 0.3% by weight.

1-T solution (ratio 1.25; aqueous solution of 25 times zinc chloride and 4 times ammonium chloride) is 40, yffijj
t%, and its true specific gravity t-j-2,063g□! 3, but the ratio of the anode mixture (4) of the actual finished product is
With the method of fyujubei, it is impossible to increase the specific gravity to 1,989/crIt, that is, 86 times the true specific gravity, and even the best conventional product was about -96 g/cnr. This was due to incomplete degassing of the anode mixture (4), which was one of the causes of deterioration in discharge performance.

The second drawback of the conventional product is that the distribution of the electrolyte in the anode mixture (4) is uneven and the utilization rate of manganese dioxide is poor, resulting in low discharge performance and large variations. The method involves inserting the columnar mixture into an all-zinc can (1) and then injecting the remaining electrolyte.

Inevitably, the tM solution on the zinc can (1) side becomes excessive, and as a result, the electrolyte in the carbon rod (511111) becomes insufficient, and the above-mentioned situation occurs.

The disadvantage of the i3 case is that as mentioned above, the remaining 'fi' solution enters the anode mix 7F1 part because there is an excess of 'f' liquid in the anode mix 7F1 part, so there is no possibility of leakage after the completion of the pond assembly, especially under high temperature conditions. The problem is that liquid accidents are more likely to occur.

The fourth drawback is that when the electrolyte is injected, splashing of the electrolyte may occur, which corrodes the inner and outer surfaces of the zinc can (1) and makes the seal of the sealant (7) incomplete. The fifth disadvantage is that productivity is not good.

The first is that the production line gets dirty when the electrolyte is injected, reducing work efficiency.The second is that a storage space is required to mature the mixture, and the storage amount and storage period are limited. This problem complicates the manufacturing process.

In order to improve these drawbacks, the present inventors have proposed the following manufacturing method. That is, first, manganese dioxide, a conductive material, and all the required electrolytes are mixed, and then lightning is applied in the middle.
By eliminating the M solution injection step and granulating the mixture containing the electrolytic FFF solution while applying impact, the air in the mixture was released and the electrolyte was homogenized.9. Thereafter, the granule mixture is completely crushed and sealed in the cathode can (1), thereby improving the above-mentioned drawbacks.

Next, the details will be explained.

First, electrolysis - 84.5% manganese dioxide, 15.0% acetylene Bragg as a conductive material, and 0.5% zinc oxide.
Overlay 100 volumes of solid material with 71% water by weight.

Add 55 volumes of electrolyte containing 25% zinc chloride and 4% by weight of ammonium chloride and mix 1).
A mixture with a bulk density of 0.8-0.99/CC is produced. In this case, the total amount of electrolyte added is 9, which is different from the conventional method. The composition of this mixture is exactly the same as that of the conventional product.

Figure 2 shows the equipment for granulating this mixture while applying impact.
``1'' In Figure 9, which is a fully illustrated cutaway perspective view, the (goods) is a silk-like container with a center tube 05 in the center.

(L12 is a high-tension spring that supports the conte duck 41, and 07 is a vibration motor.

When the mixture prepared as described above is immediately put into the container α4) GC without being aged and the motor (Iη is operated), three-dimensional high vibration is applied to the container 041.

As shown by the arrow in the mixture μ diagram, the mixture starts to slowly rotate and is granulated into granules with diameters of −0, 5, and −5 in 488 minutes. During this time, the mixture collided with the wall of the container α,
At this time, the shock caused by the vibrations and the collisions between the mixtures causes deaeration and homogenization of the electrolyte.

Figure 3 shows the cathode can (1
) is a cross-sectional view showing the process of filling a container (1).
OQ9 formed by the guide portion (18c) is a piston that moves up and down within the measuring portion (18a).

It is a mixture of granules.

In this process, after pulling up the piston a9, the measuring section (18
Add a predetermined amount of granular mixture (2G) to a), and add the piston (1
! By press-fitting I into the measuring part (18a), the zinc can (1) loaded with the separator (2) and the bottom paper (3) is filled with the K anode mixture (4). At this time, the zinc can (1) is designed to move downward as the piston 01 moves.

The movement is adjusted so that an appropriate pressure is applied to the filled anode mixture (4). Therefore, contact between anode mixture (4) and separator (2) and N1 to separator (2)
Penetration of solution is uniform. In addition, the granule mixture is mainly granulated in the granulation part (18b), and the guide part (18c
), the grain shape is not maintained at all.

When the filling of the anode mixture (4) is completed as described above, the oath paper (6) is inserted into the zinc can (1), and the carbon rod (5) is inserted into the anode through the hole made in the center of the oath paper (6). Press into mixture (4).

By press-fitting the carbon rod (5), the anode mixture (4) is further degassed and its specific gravity increases, and the separator (21'k
The contact with the zinc can (1) through the zinc can becomes even better, and the tπ electrolyte permeates into the separator (2) more completely.

The specific gravity of the anode mixture (4) produced in this way is approximately 2.
-00 g/CI4, the highest specific gravity of conventional products 1.9
It has been replaced with an extremely high value compared to f+ 97cm.

These values are the true specific gravity of 2.0637 determined from the above composition.
/c shoulder is 97ch and 95%, respectively.

However, in the above method, mixture 1 adheres to the inner wall of container θ in the granulation process, and shock and vibration are not sufficiently transmitted to the mixture, so degassing is still insufficient and the diameter of granular mixture Q1 There were drawbacks such as large variations and a long time required for granulation.

The purpose of this invention is to improve the above-mentioned drawbacks by mixing a small amount of tetrafluoroethylene resin into the mixture before granulation.

The present inventors have investigated various granulation accelerators that are difficult for the mixture to adhere to the inner wall of the container I, and have a size of 41 (up to 1). We have found that it is effective to add a small amount of tetrafluoroethylene resin, which has excellent non-adhesive properties, to the mixture before granulation.

That is, such a mixture was subjected to high vibration La17JrLtJc results for 385 minutes using the apparatus shown in Fig. 2 - diameter o, 5" i5 above, 4. On or less, bulk density 0.95.@100 or more,
1.10 i/CC or less 9 or less Particles 4-Mixture Q On the other hand, the one without the addition of tetraethylene has a granulation time of 4-8 minutes and a diameter of 6. 5 F7: That's all, 5. gflF or less 1 i?
6 density O. SO&/CC or more, 1.20,9/Co or less 9 grain specific gravity 1.92,9/Pe or moree 2-02 5
'/crit or less. In other words, those with tetrafluoroethylene added are compared to those without. It is well degassed, there is little flutter in the above Km, and the granulation time can be shortened. Using the above-mentioned granular mixture in history,
The specific gravity of the anode mixture (4) of the dry cell battery manufactured by the process explained with reference to FIG. 3 is 1.991 without additives! / mer (true specific gravity of 96.5 rice cakes) or more, 2[31/cr/l (X
The specific gravity is 88.4'i-) or less, while the one with tetrafluoroethylene added has a specific gravity of 2.02 g lCI & (97.9 g of true specific gravity) or more*22.04 jj/cr! (
p, 98.9% of specific gravity) or less.

Next, an example will be explained.

The conventional SUM-1 type dry battery A, and the dry battery B, which has the same specifications but was produced by granulation for 6 minutes without adding tetrafluoroethylene, and the same specifications, but also made with tetrafluoroethylene '2o,
Dry battery C manufactured by adding oos weight% and granulating for 4 minutes
The results of tests on discharge performance and leakage resistance performance are shown in Table tII and Table 2.

Table 1 Table 2 Table 1 shows the average value and standard deviation of the discharge duration at 20°C for each of the 50 samples immediately after production.
Is dry cell B a conventional dry cell? Although it is significantly superior to 1I12A, dry cell C has even better discharge performance, and the effect of tetrafluoroethylene is clearly recognized.

Table 2 also shows the number of leaks of 50 of each sample immediately after manufacture under a 2Ω load at 20°C for 3 months, and the number of leaks of 100 of each sample after storage at 60°C for 3 months. As shown, dry batteries B and O are clearly superior in leakage resistance, and the effect of tetrafluoroethylene is also recognized.

As mentioned above, dry batteries B and O are significantly superior to conventional dry fuel oil A and K because of the complete degassing of the anode mixture (4) and the uniform electrolyte distribution. However, it is obvious that the fourth and fifth drawbacks of the conventional method described above are eliminated because the injection of electrolyte and the aging of the mixture are not performed during the intermediate steps.

Furthermore, dry cell C is even better than dry cell B because the mixture containing tetrafluoroethylene is less likely to adhere to the inner wall of container Q4 during granulation, so deaeration is more complete. This is due to the fact that the sizes of the tubes are uniform and the variation in the strength of the anode mixture (4) is reduced.

After that, as a result of various experiments and studies, we found that the anode mixture (
4) The amount of tetrafluoroethylene in it is 0. If QOO is less than 17i, it is the same as the case where it is less than or equal to Roti, and the above effect cannot be obtained3.On the other hand, if Q, (12i1j or more) is less than Therefore, the utilization rate of manganese dioxide decreases, resulting in a decrease in discharge performance, which is not suitable for practical use.

In addition, the granular mixture 01N has a diameter of 0.5 mm or more, 5° Or
Bulk density is 0.90g/QC or more, 1.20g
It has become clear that the preferred range is a range in which the specific gravity of the 9 grains is 1.929 /c++ or less.

The reason for this is as follows: 0. If the diameter is smaller than 0.5, the deaeration is insufficient, and the Nwf liquid after production is 1i
ji, 111I and movement of ions during operation is obstructed by air, resulting in low discharge performance and large variations, which is undesirable. On the other hand, in the case of 5.611 m or more, the amount of the granular mixture (total) replenished into the measuring part (18a) of the filling jig α varies, and as a result, the anode mixture (total) filled into the zinc can (11) The amount of 41 varies, which is not preferable.

If the bulk density is smaller than o, eog7cc, granulation will be incomplete and deaeration will be insufficient, resulting in low discharge performance and large variations in anode mixture (4) filled into the zinc can (1). The dispersion in the amount becomes large, and the discharge performance and anti-foaming performance are inferior. On the other hand, the bulk density is 1.20g/c
If it is larger than c, the granulation becomes excessive and free electrolyte oozes out onto the surface of the two particles, and at the same time the particle diameter also becomes considerably large. For this reason, the flow of the 9-granule mixture (a) becomes poor, and the variation in the amount of the granule mixture supplemented to the measuring section (18a) becomes large.

As a result, the anode mixture (4) filled in the zinc can (1)
This is undesirable because the variation in the values becomes large, which poses a problem in the production of dry batteries.

When the specific gravity of the necked particles is less than 1.92 g/i, degassing is insufficient, resulting in low discharge performance and large variations.

In the above example, the mixture was granulated using a three-dimensional high-vibration device as shown in Fig. 2, but if the device is capable of granulating while applying impact, other devices such as two-dimensional high-vibration device can be used. Similar effects can be obtained with devices such as devices.

Ball: This invention has been explained above +9. A mixture of all electrolytes and a solid material containing tetrafluoroethylene resin is used! 'l
By granulating the granular mixture and filling it into a cathode can, it can be granulated in a short time, and the specific gravity of the anode mixture is 86% or more of the true specific gravity, making it easy to degas and A dry battery with good uniformity of electrolyte distribution can be obtained, and the effects of greatly improving discharge performance and leakage resistance can be obtained.

In addition, in the manufacturing method of the present invention, injection of the electric jw solution and aging of the mixture during the process are not performed, so that the various drawbacks associated with these can be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a dry cell battery showing a conventional product and an embodiment of the present invention, and FIGS. 2 and 3 are a broken perspective view and a sectional view showing an embodiment of the downlink method of the present invention. In the figure, (+) is the Id cathode can, (4) is the anode mixture, and (to) is the granular mixture. Note that the same reference numerals in each figure indicate the same or equivalent IJ)'<. Agent: Shin Kuzuo F. Figure 3 11 Showa 11 Month 11 Mr. Commissioner of the Japan Patent Office 1, Indication of the case Patent application No. 57-3.42266
No. 2, Title of the invention: Manganese dioxide dry battery and its manufacturing method 3, Person making the amendment 4, Agent 5, Detailed description of the invention in the specification to be amended. 6. In the 15th line of page 2 of the statement of contents of the amendment, the C that says "Japanese paper" is corrected to "kraft paper, etc."that's all

Claims (4)

[Claims] (1) A manganese dioxide dry battery in which the specific gravity of the anode mixture is 96% or more of the true specific gravity determined from its composition, and the anode mixture contains tetrafluoroethylene resin. (2) The content of tetra7tethylene resin in the anode mixture is 0.
．． 0001% by weight or more and 0.02% by weight or less, the manganese dioxide dry battery according to claim (1). (3) (A) Step of mixing manganese dioxide, conductive material, and all required electrolyte solution (B) Step of granulating the mixture made in step (B) while adding 9A of carbon dioxide (C) (B) A method for manufacturing a manganese dioxide dry battery, comprising the step of crushing the granular mixture produced in step 2) and filling a cathode can with the mixture crushed in step iii). (4) Diameter of granular mixture 75K 0.5""15"
;s 5.0"' or less, cavity density is o, eog7cc or more, 1.20.9/Co, lower grain specific gravity is 1.92
g10! A method for manufacturing a manganese dioxide dry battery equipped with an RC tube Fc requirement, item (3), characterized by the above.