JP2006338907A - Cylindrical battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical battery few in insulation defects excellent in productivity. <P>SOLUTION: The cylindrical battery comprises a positive electrode envelope 11 which also serves as a positive electrode terminal and is in a shape of a cylinder with a bottom; a separator 15 which is placed in the positive electrode envelope 11, and is in a shape of a cylinder with a bottom; a positive electrode mixture 14 which is placed between the inner surface of the positive electrode envelope 11 and the outer surface of the separator 15; and a gelatinous negative electrode 19 with which the inside of the separator 15 is filled. The cylinder 15a of the separator 15 is a material into which a colored adhesive bonds separator raw material sheets together. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cylindrical battery such as an alkaline battery.

  While the use of portable AV equipment such as notebook PCs, CD players, MD players, and liquid crystal televisions, as well as ultra heavy loads and heavy loads such as digital cameras and mobile phones, recent alkaline dry batteries have been required. As the negative electrode filling amount increases, that is, the capacity increases, the separator is made thinner.

  As a separator for a cylindrical battery such as an alkaline battery, a separator in which a base plate is integrated with a cylindrical part obtained by bonding separator base paper into a cylindrical shape with an adhesive is used. Adhesion between the cylindrical portion and the bottom plate portion is made by, for example, thermocompression bonding, and as shown in Patent Document 1, it is high by coloring a liquid that permeates the end surface of the cylindrical separator (cylindrical portion) and the bottom separator (bottom plate portion). It is known that thermocompression strength can be obtained.

On the other hand, an adhesive is used for processing the cylindrical portion of the separator, and if the thickness of the separator base paper is reduced, there is a problem that a slight adhesion failure tends to cause an insulation failure. That is, if there is unevenness in the adhesion of the cylindrical portion of the separator, it will be easily peeled off when the separator is inserted into the positive electrode container. If the separator base paper is thin, the peeled portion is easily broken, so that an increase in insulation failure and a decrease in the operating rate of the production line become remarkable. As countermeasures, it is conceivable to increase the electrical resistance or reduce the line speed by winding the separator a plurality of times, but this leads to a decrease in battery capacity and operating rate.
JP 2002-216732 A

  It is an object of the present invention to provide a cylindrical battery with little insulation failure and excellent productivity.

A cylindrical battery according to the present invention includes a bottomed cylindrical positive electrode container also serving as a positive electrode terminal, a bottomed cylindrical separator disposed in the positive electrode container, an inner peripheral surface of the positive electrode container, and an outer periphery of the separator A cylindrical battery comprising a positive electrode mixture disposed between surfaces and a gelled negative electrode filled in the separator,
The cylindrical portion of the separator is obtained by pasting separator base paper into a cylindrical shape with a colored adhesive.

  Since the color of the adhesive is white or milky white and is the same system as the color of the separator base paper, it is very difficult to accurately grasp the application state of the adhesive. By using the above-described cylindrical portion, it is possible to easily check the distribution of the adhesive, so that it is possible to accurately determine a separator that is molded into a cylindrical shape but has insufficient adhesion. It becomes possible. As a result, it is possible to reduce peeling of the separator cylindrical portion when housed in the positive electrode container, so that it is possible to suppress insulation failure due to seepage of the negative electrode gel from the separator and to prevent the production line from being broken by the separator. Stops can be avoided.

  Furthermore, even when the separator base paper is thinned, the number of windings is not increased, that is, it is not necessary to increase the amount of adhesive, so that an increase in electrical resistance can be avoided. Moreover, not only the production line stops, but also the line speed does not need to be reduced, so that the operation rate of the production line can be improved.

  Furthermore, since the adhesive strength can be confirmed based on the degree of coloring, it is possible to perform management without using a sensor or the like.

  According to the present invention, it is possible to provide a cylindrical battery with few insulation failures and excellent productivity.

  Hereinafter, the positive electrode mixture, the separator, and the gelled negative electrode constituting the cylindrical battery will be described.

1) Separator The separator has a cylindrical portion and a bottom plate portion disposed at one opening end of the cylindrical portion.

  The cylindrical portion is processed by pasting the separator base paper into a cylindrical shape with a colored adhesive. Examples of the processing method include a flat winding method and a spiral method. In the case of the flat winding method, as shown in FIG. 1, a colored adhesive is applied to both of the long side portions 1a and 1b of the strip-shaped separator base paper 1, and this is spirally formed with the short side as the winding axis. A cylindrical part is obtained by winding. Alternatively, after winding in a spiral shape with the short side as the winding axis without applying an adhesive to the long sides 1a and 1b of the strip-shaped separator base paper 1, the corner 1c at the end of the short side is wound. , 1d or the entire end of the winding on the short side is coated and fixed with a colored adhesive to obtain a cylindrical portion. In the case of the spiral method, as shown in FIG. 2, three sets of strip-shaped separator base papers 2 to 4 are prepared. A colored adhesive is applied to each of the long side portions 5 to 10. A cylindrical portion is obtained by winding the separator base papers 2 to 4 while gradually shifting them while winding them in a spiral shape. Note that the number of separator base papers used is not limited to three, and can be two or four or more.

  As separator base paper, insulating porous sheets, such as a nonwoven fabric, can be mentioned, for example. The separator base paper is preferably formed from a hydrophilic material.

  The thickness of the separator base paper can be in the range of 100 to 140 μm. When the thickness of the separator base paper is less than 100 μm, the separator may be broken due to insufficient strength of the separator even when the adhesive is uniformly applied. On the other hand, if the thickness of the separator base paper exceeds 140 μm, a high capacity may not be obtained. A more preferable range is 110 to 130 μm.

  Examples of the adhesive include those having a vinyl acetate resin as a main component.

  The colorant added to the adhesive is preferably a food additive containing a natural pigment and / or a synthetic pigment, an ink containing a dye, or the like. Among these, food additives are preferable because they have low toxicity and can reduce the risk of side reactions in the battery. Moreover, since the food additive can be easily made into a powder, there is an advantage that the concentration can be easily adjusted.

  As food additives containing natural pigments, red pigments containing red yeast rice pigment (for example, KC Red MY, KC Red MA, KC Red MA-2, KC Red MR, KC Red MR-2), green pigment preparations (For example, product names are KC Green M, KC Green GO-2), gardenia blue pigments (for example, product names are KC Blue No. 5P, KC Blue KB-6, KC Blue No. 9), blue pigment systems (for example, product names) Is KC Blue KB-15), red color containing anthocyanin dyes (for example, KC Red AC, KC Red RA-20, KC Red RA-2, KC Red RC-5, KC Red EL, KC Red RD- 2, KC Red MV, KC Red NNK, Shiso Color 20, Shiso Color 100) and the like.

  Examples of food additives containing synthetic pigments include red food additives (for example, Red No. 102).

  The ink is preferably a dye system because it can reduce the risk of side reactions in the battery.

  The concentration of heavy metal in the ink is preferably 1 ppm or less. This is because if the heavy metal concentration exceeds 1 ppm, side reactions may occur due to heavy metals mixed in the electrolyte. Examples of heavy metals include Cd, Cr, Pb, Hg, and the like.

  Examples of the dye-based ink having a heavy metal concentration of 1 ppm or less include the red, indigo and green colors of Shachihata stamp ink (for sol stamp stand only) S-1 and S-3 (Shachihata Co., Ltd.).

  The color type of the colorant is preferably red, blue, or green from the viewpoint of visibility.

  The addition amount of the colorant is desirably 0.5 to 10% by weight with respect to 100 parts by weight of the adhesive. If the addition amount is less than 0.5% by weight, the visibility may be insufficient. On the other hand, if the addition amount exceeds 10% by weight, the adhesive function of the adhesive may be impaired. A more preferable range of the addition amount is 0.5 to 5% by weight, and a further preferable range is 0.5 to 3% by weight.

  The bottom plate portion can be formed from a separator base paper. Examples of the separator base paper include the same ones as described in the cylindrical portion. The bottom plate portion can be integrated with the cylindrical portion by, for example, thermocompression bonding.

2) Positive electrode mixture A positive electrode mixture contains a positive electrode active substance, and can contain a electrically conductive agent and a binder as needed. Examples of the positive electrode active substance include manganese dioxide and nickel oxyhydroxide.

3) Gelled negative electrode For the gelled negative electrode, for example, a gelled zinc negative electrode containing a non-catalyzed zinc alloy powder, an alkaline electrolyte and a gelling agent (for example, polyacrylic acid) can be used.

  An alkaline battery according to an embodiment of the present invention will be described with reference to FIG.

  The positive electrode can (positive electrode container) 11 has a bottomed cylindrical shape, and the bottom surface protrudes outwardly, and this convex portion functions as the positive electrode terminal 12. Further, in the vicinity of the opening of the positive electrode can 11, a step 13 (bead portion) protruding inward is provided so that an insulating gasket described later is disposed. The positive electrode can 11 can be formed, for example, from a metal such as a cold-rolled steel plate having a nickel plating or nickel alloy plating layer.

  On the inner peripheral surface of the positive electrode can 11, a conductive film (not shown) mainly composed of graphite powder is formed on a portion located above the step 13.

  The cylindrical positive electrode mixture 14 is accommodated in the positive electrode can 11, and the outer peripheral surface thereof is in contact with the conductive coating on the inner surface of the positive electrode can 11. The positive electrode mixture 14 is obtained, for example, by mixing a positive electrode active substance and a conductive agent, and press-molding them into a hollow cylinder with a predetermined pressure using a molding die. The bottomed cylindrical separator 15 has a cylindrical portion 15a processed by bonding a separator base paper into a cylindrical shape with a colored adhesive, and a bottom plate portion 15b integrated with an opening of the cylindrical portion 15a. . Such a separator 15 is disposed in the hollow portion of the positive electrode mixture 14.

  An insulating gasket 16 having a double annular structure is disposed in the positive electrode can 11 so as to close the opening of the separator 15. The insulating gasket 16 is made of a polyamide resin such as nylon 6 or 6, for example. The negative electrode terminal plate 17 also serves as a sealing plate for the positive electrode can 11, and is caulked and fixed to the opening of the positive electrode can 11 via an insulating gasket 16. The negative electrode terminal plate 17 can be formed from, for example, a metal such as a cold-rolled steel plate formed with a nickel plating or nickel alloy plating layer. The metal washer 18 is interposed between the double annular portions of the insulating gasket 16.

  The gelled negative electrode 19 is filled in the separator 5. For example, the negative electrode current collector rod 20 made of brass is fixed to the inner surface of the negative electrode terminal plate 17, penetrates through the insulating gasket 16, and the tip is inserted into the gelled negative electrode 19.

[Example]
Examples of the present invention will be described in detail below.

Example 1
A cold rolled steel plate material on which a nickel-iron alloy plating layer having a thickness of 1 to 2 μm was previously formed was used to produce a bottomed cylindrical positive electrode can. A conductive film mainly composed of graphite powder was formed on the inner surface of the positive electrode can except for the portion in contact with the gasket of the opening. The conductive coating is applied by diluting a conductive paint mainly composed of graphite powder with a low-boiling organic solvent such as methyl ethyl ketone, and spraying it on the inner surface of the positive electrode can with a spray gun. It was made not to apply to the part which touches the gasket of the part. After applying the conductive paint with a spray gun, the solvent was evaporated with a dryer. The thickness of the remaining conductive film is preferably about 1 to 10 μm.

  Manganese dioxide powder and graphite powder were mixed, and this was pressure-molded into a hollow cylindrical shape at a predetermined pressure using a molding die to obtain a positive electrode mixture. In order to increase the discharge capacity, the graphite powder content in the positive electrode mixture is preferably 3 to 10% by weight.

  Three separator base papers having a thickness of 40 μm made of a nonwoven fabric of vinylon and polyvinyl alcohol (PVA) fibers were prepared, and a colored adhesive was applied to the long side portion of each base paper. An adhesive containing a vinyl acetate resin as a main component was used. 0.5 g of green dye-based ink (Shachihata stamp ink (only for sol stamp stand) S-1 of Sachihata Co., Ltd., content of heavy metal (Cd, Cr, Pb and Hg) is 0 ppm) to 100 g of this adhesive. Weight percent was added to color the adhesive. Next, a cylindrical portion was produced from the three separator base papers by a spiral method.

  A separator base paper having a thickness of 40 μm made of a nonwoven fabric of vinylon and PVA fibers was punched out in a circular shape to obtain a bottom plate portion. The bottom plate portion was thermocompression bonded to one open end of the cylindrical portion to obtain a bottomed cylindrical separator.

  A non-glazed zinc alloy powder, an alkaline electrolyte, and polyacrylic acid as a gelling agent were mixed to obtain a gelled zinc negative electrode.

  A JIS standard LR6 type (AA) alkaline dry battery shown in FIG. 1 was assembled using a positive electrode can, a positive electrode mixture, a separator, and a gelled zinc negative electrode on which a conductive film was formed.

(Example 2)
The same procedure as described in Example 1 except that 0.5% by weight of a red food additive (product name: KC Red MA-2) using natural pigment as a raw material is added and the adhesive is colored. A JIS standard LR6 type (AA size) alkaline battery was assembled in the same manner as in Example 1.

(Example 3)
Example 1 except that 0.5% by weight of a red food additive (product name: Red No. 102) using a synthetic dye as a raw material is added to the same adhesive as described in Example 1 to color the adhesive. In the same manner, a JIS standard LR6 type (AA size) alkaline battery was assembled.

Example 4
Red dye-based ink {Shachihata stamp ink from Sachihata Co., Ltd. (for sol stamp stand only) S-1; heavy metal (Cd, Cr, Pb and Hg) content 0ppm} so that lead oxide and Pb concentration become 1ppm Added. A JIS standard LR6 type (AA) alkaline battery except that 0.5% by weight is added to the same adhesive as described in Example 1 and the adhesive is colored. Assembled.

(Example 5)
In the same adhesive as described in Example 1, indigo dye-based ink (Shachihata stamp ink (only for sol stamp stand) S-1 from Shachihata Co., Ltd.), heavy metal (Cd, Cr, Pb and Hg) content JIS standard LR6 type (AA) type alkaline battery was assembled in the same manner as in Example 1 except that 0.5 ppm by weight was added and the adhesive was colored.

(Example 6)
Example 1 except that 0.5% by weight of a green food additive (product name: KC Green M) made from a natural pigment is added to the same adhesive as described in Example 1 to color the adhesive. In the same manner, a JIS standard LR6 type (AA size) alkaline battery was assembled.

(Example 7)
Implemented except that 0.5% by weight of a blue food additive (product name: KC Blue KB-15) made from natural pigment is added to the same adhesive as described in Example 1 and the adhesive is colored. A JIS standard LR6 type (AA size) alkaline battery was assembled in the same manner as in Example 1.

(Example 8)
A JIS standard LR6 type (AA size) alkaline battery was assembled in the same manner as in Example 2 described above, except that the amount of the colorant added was 3% by weight.

Example 9
A JIS standard LR6 type (AA size) alkaline dry battery was assembled in the same manner as in Example 2 described above except that the amount of the colorant added was 5% by weight.

(Example 10)
A JIS standard LR6 type (AA size) alkaline battery was assembled in the same manner as in Example 2 described above, except that the amount of the colorant added was 10% by weight.

(Comparative example)
A JIS standard LR6 type (AA) alkaline battery was assembled in the same manner as in Example 1 except that the adhesive was not colored.

In the obtained alkaline dry batteries of Examples 1 to 10 and Comparative Example, peeling investigation, electrical characteristics, and line operation rate comparison were performed. The results are shown in Table 1 below. The peeling investigation was performed before integrating the bottom plate portion with the cylindrical portion of the separator, and the number of peeling in 10,000 pieces is shown in Table 1. The open circuit voltage (OV), internal resistance (Imp), closed circuit voltage (CV), and short circuit current (SC) showed the average value of 1000 batteries. Further, the operation rate (%) was calculated from {(time required to manufacture 600,000 batteries−line downtime due to defective separator) / (the manufacturing time) × 100}.

  As is clear from Table 1, in Examples 1 to 10 in which the adhesive used for producing the cylindrical portion of the separator was colored, the separator was not peeled off, and was excellent in electrical characteristics such as voltage, resistance, and short-circuit current. The line operating rate was also improved by about 10% compared to the comparative example, confirming the magnitude of the effect.

  According to the comparison of Examples 2 and 8 to 10, the number of peeling of the separator increases as the addition amount of the colorant is reduced to 0.5 to 10% by weight, 0.5 to 5% by weight, and 0.5 to 3% by weight. It can be seen that the electrical characteristics are improved.

  On the other hand, in comparative examples using an uncolored adhesive, the separators are often peeled off, so that the operation rate is low. Moreover, the average value of the short circuit current became low compared with Examples 1-10.

  As described above, by coloring the adhesive, it is possible to reduce the occurrence of peeling and tearing in the separator process of the alkaline dry battery manufacturing method, and it is possible to improve the sorting accuracy of defective products, thereby improving the battery characteristics. can do. In addition, the utilization rate can be improved.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The schematic diagram which shows the flat winding system which is an example of the preparation methods of the cylindrical part of a separator. The schematic diagram which shows the spiral system which is an example of the preparation methods of the cylindrical part of a separator. The typical sectional view showing the alkaline dry battery which is one embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1-4 ... Separator base paper, 11 ... Positive electrode can, 12 ... Positive electrode terminal, 14 ... Positive electrode mixture, 15 ... Separator, 15a ... Cylindrical part, 15b ... Bottom plate part, 16 ... Insulation gasket, 17 ... Negative electrode sealing board, 18 ... Metal washer, 19 ... gelled negative electrode, 20 ... negative electrode current collector rod.

Claims (3)

A bottomed cylindrical positive electrode container also serving as a positive electrode terminal, a bottomed cylindrical separator disposed in the positive electrode container, and a positive electrode composite disposed between the inner peripheral surface of the positive electrode container and the outer peripheral surface of the separator. A cylindrical battery comprising an agent and a gelled negative electrode filled in the separator,
The cylindrical portion of the separator is a cylindrical battery in which a separator base paper is bonded in a cylindrical shape with a colored adhesive.   The cylindrical battery according to claim 1, wherein the adhesive is colored with a food additive.   2. The cylindrical battery according to claim 1, wherein the adhesive is colored with a dye-based ink.

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