JP2001210302A - Bag-type separator for lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bag-type separator for a lead-acid battery, which corresponds to thin-type of flat plate part of flat plate sheet, and even if the flat plate sheet is wound up as a coil form, it doesn't get out of its shape changed, and does not produce a swelling deformation of flat plate part of flat plate sheet. SOLUTION: Plural rows of rib are installed at least in a single face of flat plate sheet, and it is the bag-type separator for the lead-acid battery, which is folded in two at the central part and welded at an each side edge of light and left, and by installing a bent rib which lasts in perpendicular direction from bottom to upper side as the rib in the flat tabular sheet, it forms a bent gas discharge route among these ribs and a mini-rib is installed which is lower than the bent rib at both side edges of the flat tabular sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag-shaped separator for a lead-acid battery having a plurality of ribs provided on at least one surface of a flat sheet. More specifically, the present invention relates to a high-performance separator capable of preventing contact between a flat portion of a flat sheet and a positive electrode plate, extending the life of a battery, and easily discharging gas generated during use of the battery.

[0002]

2. Description of the Related Art Conventionally, as a separator for a lead storage battery of this type, there is one disclosed in Japanese Patent Publication No. 4-11982. This will be described with reference to FIG. 7. By providing a plurality of linear ribs 31 arranged in parallel with each other on at least one surface of the flat sheet 1, the distance between the ribs 3 is increased.
1, 31 are formed with a straight gas discharge path 32 that does not bend from the bottom to the top in the vertical direction, and the left and right side edges of the flat sheet are shorter than the straight ribs 31. The mini ribs 33 are provided at a short interval.

[0003]

However, in order to respond to recent demands for improved battery performance and cost reduction, it is necessary to reduce the thickness of the flat portion of the flat sheet.
The conventional linear rib causes the following inconveniences in the separator manufacturing process and the battery assembling process. (1) When the flat sheet is wound in a coil shape, the flat part of the inner flat sheet is swelled and deformed by being pressed by the ribs of the outer flat sheet, and the width dimension accuracy deteriorates. If the battery is directly incorporated in the battery, the separator comes into contact with the anode plate of the battery, and the risk of shortening the service life increases. (2) If the winding tension of the flat sheet is loosened in order to prevent the flat sheet from bulging and deforming, the flat sheet may be displaced, resulting in inferior width dimension accuracy at the time of cutting, or a wound flat sheet. Of the coil loosens and the collapse of the load easily occurs. On the other hand, when the flat sheet is wound in a coil shape, the outer sheet is slightly meandered in the direction of the winding axis with respect to the inner side, and the outer sheet is rolled over the ribs of the inner flat sheet. A method of preventing the collapse of the load by allowing the ribs of the flat sheet to be placed or by narrowing the pitch between the ribs of the separator is conceivable. However, even in the former method, the ribs of the separator tend to fall, and in the latter method, when the pitch between the ribs is narrowed and the number of the ribs is increased, the electrical resistance of the separator increases. As a result, as in the former case, there is a problem that the ribs of the flat sheet tend to collapse. Accordingly, the present invention provides a lead-acid battery that can cope with a reduction in the thickness of the flat portion of the flat sheet, does not collapse even when the flat sheet is wound in a coil shape, and does not cause swelling deformation of the flat portion of the flat sheet. The purpose of the present invention is to provide a bag-shaped separator.

[0004]

In order to achieve the above object, a bag-type separator for a lead-acid battery according to the present invention has a plurality of rows of ribs provided on at least one side of a flat sheet as described in claim 1. A lead storage battery bag-like separator that is folded in two at its center and fused at both left and right side edges, wherein the flat sheet is provided with ribs bent from the vertical bottom to the top as the ribs. A bent gas discharge path is formed between the ribs, and mini-ribs shorter than the bent ribs are provided on both side edges of the flat sheet. Claim 2
The invention described in the above description is characterized in that in the bag-type separator for a lead storage battery according to the first aspect, the bent ribs are formed by sinusoidal ribs. According to a third aspect of the invention, in the lead-acid battery bag-shaped separator according to the first or second aspect, a linear gas discharge path is formed between the bent ribs from the bottom to the top in the vertical direction. It is characterized by the following. According to a fourth aspect of the present invention, in the lead-acid battery bag-shaped separator according to any one of the first to third aspects, between the bent rib row and the mini-rib row,
By providing at least two or more straight ribs from the vertical bottom to the top, a straight gas discharge path is formed between the straight ribs. According to a fifth aspect of the present invention, in the lead-acid battery bag-shaped separator according to the fourth aspect of the present invention, a rib is intermittently provided between the linear rib row and the bent rib row. It is characterized by.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The bag-type separator for a lead-acid battery of the present invention is provided with ribs bent from the bottom to the top in the vertical direction of the flat sheet. Contact can be prevented, and the life of the battery can be prolonged. In addition, since the bent rib has a direction component in addition to the vertical direction, even when a plurality of flat sheets are stacked, compared to a case where only the vertical ribs are provided, between the ribs of the lower flat sheet. It is less likely that the ribs of the upper flat sheet will sink. For this reason, even when a plurality of flat sheets are stacked and mechanically cut at a predetermined width in parallel with the vertical direction, the flat sheet is hardly displaced in the width direction due to the immersion, and dimensional accuracy can be improved. Further, it is also possible to prevent the problem of collapse of the load and the problem of falling down of the rib caused by the displacement of the outer rib at one time.

In addition, mini-ribs whose height is lower than the bent ribs of the flat sheet are provided on both side edges of the flat sheet. This improves the fusion strength and fusion dimensional accuracy of the flat sheet when the electrode plate is inserted and folded into two at the center in the vertical direction.

In addition to the bent gas discharge path,
A straight gas discharge path is formed between the bent ribs so as not to bend vertically from the bottom to the top. Thus, the gas that tends to accumulate in the bent gas discharge path can be efficiently discharged, and the battery discharge performance is further improved.

[0008] At least two or more linear ribs are provided between the bent rib rows and the mini-rib rows from the bottom to the top in the vertical direction, so that the linear ribs are provided between the linear ribs. Since the gas discharge path was formed, the gas discharge performance was further improved.

Further, as the bending ratio of the ribs forming the bent gas discharge path increases, the region where the ribs do not exist from the bottom to the top in the vertical direction between the bent ribs and the linear ribs. It is formed more widely. For this reason, a rib is provided intermittently between the bent rib row and the linear rib row. Thereby, the contact between the flat plate portion of the flat sheet and the anode plate when the battery is assembled is prevented, and the oxidative deterioration of the flat sheet by the anode plate can be suppressed.

[0010]

Next, an embodiment of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 shows an embodiment of a bag-shaped separator for a lead storage battery according to the present invention, and has a height (H) of 133.5 mm.
X a flat sheet 1 having a width (W) of 152 mm and a thickness of 0.2 mm, and a sinusoidal height of 0.1 mm with a period of 1000 mm.
A plurality of 8 mm ribs 2 are provided in a nested manner, and 15 mm (W2) between the ribs 2 and 2 is used as the flat plate portion 3. Thus, a bent gas discharge path 5 is formed between the sinusoidal ribs 2 and 2 provided from the bottom to the top in the vertical direction. The flat sheet 1 formed as described above is folded at the center 6 and fused at both side ends (1S) to form a bag-shaped separator. In this embodiment, 0.2 mm mini ribs 4 shorter than the sinusoidal ribs 2 are provided at 1 mm intervals (W) on both left and right side edges of the flat sheet 1.
4). In this embodiment, the mini-ribs 4 are linear from the bottom to the top in the vertical direction. However, the mini-ribs 4 are zigzag, wavy, or horizontal linear (intersecting with the sinusoidal ribs).
It is not particularly limited to these. Preferably, the interval between the mini-ribs is smaller than the interval between the sinusoidal ribs. In this embodiment, the bending ratio of the rib is set to 7/700 to 15/700 (horizontal direction / vertical direction). When the ratio is less than 7/700, that is, when the component in the vertical direction of the rib increases, the effect of preventing collapse of the load, swelling deformation, variation in dimensional accuracy of the bag width, falling of the rib, and deterioration of the flat plate portion decreases. On the other hand, when the ratio exceeds 15/700, the vertical component of the rib decreases, and the gas discharge performance deteriorates. Next, the flat sheet 1
A specific manufacturing method will be described. The flat sheet 1 is made of high-density polyethylene having a weight average molecular weight of 500,000 to 3,000,000.
20 parts by weight and a powder 1 having a specific surface area of 150 to ²⁰⁰ m ² / g
It is produced as follows from a melt-kneaded product of 5 to 40 parts by weight and 40 to 70 parts by weight of mineral oil. That is, first, the flat sheet 1 is ribbed by passing between a pair of forming rolls having grooves so that a desired rib shape is obtained on the outer peripheral surface of the roll, and then, the sheet-like material thus ribbed Is extracted by immersing in a solvent to extract and remove a part of the mineral oil. In this example, the residual oil amount was extracted up to 14% by weight. Then, the flat sheet 1 thus obtained is obtained.
Is bent at the center portion and the both side edges are fused to form a bag-shaped lead-acid battery bag-shaped separator as described above.

(Embodiment 2) In the embodiment shown in FIG.
Different from those shown in (1), sine-wave shaped ribs 2 are provided on a flat sheet 1 at 15 mm intervals (W2) so as not to be nested, and a flat plate portion 3 is formed between the ribs 2 and 2. As a result, a gas discharge path bent from the bottom to the upper part is formed between the ribs 2, 2, and a straight 5 mm wide (W2 ′) gas that is not bent at the center of the gas discharge path 5. The discharge path 7 is formed. The left and right side edges (1S) of the flat sheet 1 are provided with mini-ribs 4 shorter than the ribs 2. In addition, the flat sheet 1 of Example 2 and the following was manufactured by the same manufacturing method as the flat sheet 1 of Example 1.

(Embodiment 3) In the embodiment shown in FIG. 3, the distance between the row of the sinusoidal ribs 2 and the row of the mini-ribs 4 is 0.1 mm.
Two linear ribs 8 having a width of 6 mm (W8) were provided. As a result, a straight gas discharge path 9 is formed between the straight ribs 8, 8 from the bottom to the top in the vertical direction. Also, by making the height of the linear ribs higher than the mini-ribs, the height of the mini-ribs is too low to be detected, so that the bent ribs are not accurate, and the width is not accurate. The dimensional accuracy at the time can be improved, and the dimensional accuracy of the fused portions at the left and right side edges of the flat sheet can be improved. Except for this point, the configuration was the same as that of the first embodiment.

(Embodiment 4) In the embodiment shown in FIG. 4, the distance between the row of the sinusoidal ribs 2 and the row of the mini-ribs 4 is 0.1 mm.
Two straight ribs 8, 8 were provided from the bottom to the top in the vertical direction with a width of 6 mm (W8). As a result, a straight gas discharge path 9 formed between the straight ribs 8 is formed. Except for this point, the configuration was the same as that of the second embodiment.

(Embodiment 5) In the embodiment shown in FIG. 5, a U-shaped rib 10 is provided in a region where no rib exists between the rib row of the sinusoidal ribs 2 and the rib row of the linear ribs 8. It was provided intermittently. Except for this point, the configuration was the same as that of the third embodiment.

(Embodiment 6) In the embodiment shown in FIG. 6, a linear rib 11 is intermittently provided in a region where there is no rib between the rib row of the sinusoidal ribs 2 and the rib row of the linear ribs 8. It was made to be provided. Except for this point, the configuration was the same as that of the fourth embodiment. In the fifth and sixth embodiments, the U-shape 10 and the linear rib 11 are provided intermittently. However, the present invention is not particularly limited as long as it is provided in a region where no rib exists. Not zigzag, wavy,
The shape may be a horizontal straight line (intersecting with a sinusoidal rib, a U-shape, a V-shape, a point shape) or the like.

COMPARATIVE EXAMPLE 1 As shown in FIG. 7, the lead-acid battery bag-shaped separator of Comparative Example 1 has linear ribs 31 provided on a flat sheet 1 and a flat plate portion 2 between the ribs 31. The mini-ribs 33 are provided on the left and right side edges of the flat sheet 1 so as to be narrower than the ribs 31 and 31. Thus, a linear gas discharge path 32 is formed vertically from the bottom to the top.

(Comparative Example 2) A bag-shaped separator for a lead-acid battery of Comparative Example 2 has a nested sinusoidal rib 34 provided on the entire surface of the flat sheet 1 as shown in FIG.
Thus, a gas discharge path 35 bent vertically from the bottom to the top by the sinusoidal ribs 34 is formed.

Next, when the separators of Examples 1 to 6 of the bag-type separator for a lead-acid battery of the present invention and Comparative Examples 1 and 2 which are conventional bag-type separators for a lead-acid battery are manufactured, when the battery is assembled and manufactured, The evaluation results at the time of use are shown in Table 1 below.

[0019]

[Table 1] In addition, about each said evaluation, it performed as follows. Packing collapse: A separator with a width of 118 mm is wound 750 m onto a 10-inch diameter paper tube, and a transport test is performed.
Was evaluated. Swelling deformation: The winding tension at the time of winding up the product was changed, and no swelling was evaluated as ○, and swelling was evaluated as x. Deviation at the time of bag processing: When the separator is folded in two to form a bag-like separator formed by fusing both ends with ultrasonic waves, the rate of occurrence of bending deviation per 1,000 separators is as follows:
Those with less than 3% were evaluated as ○, and those with 3% or more were evaluated as x. Rib collapse: The polyethylene resin was extruded and wound into a sheet, and the presence or absence of rib collapse at the time of correcting meandering was evaluated. Peeling of the fused part: When bagging the separator, fusion is performed by ultrasonic waves.
Less than 1% per 000 sheets was evaluated as ○, and more than 1% as X. Gas discharge: The discharge of gas generated during overcharging is visually confirmed using a single-cell battery using a transparent battery case, and the gas discharge rate is extremely high, such as a separator composed of only linear ribs.に for high ones, slower than the gas discharge rate, but no gas stagnation in the middle △,
When the gas might be stagnated during the discharge, the evaluation was evaluated as x. Deterioration of separator: The life under heavy load specified in JIS D5301 was measured, and relative evaluation was performed with Comparative Example 1 being 100%.
Less than 0% was rated as Δ, and more than 120% was rated as ○. In addition, regarding the comprehensive evaluation, 1 point for each evaluation item, 0 point for Δ,
The sum was calculated by setting x to -1 points, and two or more points were evaluated as the bag-type separator for a lead storage battery of the present invention.

As is clear from Table 1, Examples 1 to 6 of the present invention were excellent in evaluation of load collapse, swelling deformation, displacement during bag processing, and rib falling down during separator production, and bag fusion during battery assembly. It can be seen that the peeling at the attachment portion is small. In particular, Examples 2, 4, and 6 are excellent in gas discharge properties, and Example 6 is particularly excellent in separator deterioration resistance.

[0021]

According to the bag-type separator for a lead-acid battery according to the first aspect of the present invention, bent ribs are provided on a flat sheet, and mini-ribs are provided on both side edges of the flat sheet to reduce lead. It is possible to improve the collapse of the load when the flat sheet is wound up during the production of the storage battery bag separator, the swelling deformation of the flat plate portion, the falling of the ribs, the poor bag dimensional accuracy at the time of cutting, and the bag fusing property at the time of assembling the battery. According to the bag-type separator for a lead-acid battery according to the second aspect of the present invention, a straight gas discharge path is formed between the bent ribs from the bottom to the top in the vertical direction. At times, gas discharge becomes easier, which can contribute to further improvement in battery discharge performance. According to the bag-shaped separator for a lead-acid battery according to the third aspect of the present invention, at least two or more linear ribs are provided between the bent rib row and the mini-rib row, so that both side edges of the flat sheet are provided. The dimensional accuracy at the fused portion of the part is improved, and the electrode plate can be stably inserted when the battery is assembled. According to the bag-type separator for a lead storage battery according to claim 4 of the present invention, since the ribs are provided intermittently between the linear rib rows and the bent rib rows, the flat portion of the flat sheet is formed. And the anode plate can be prevented from contacting with each other, and the oxidative deterioration of the separator by the anode plate can be suppressed.

[Brief description of the drawings]

FIG. 1 is a plan view showing one embodiment of a bag-type separator for a lead storage battery of the present invention.

FIG. 2 is a plan view showing another embodiment of the bag-shaped separator for a lead storage battery of the present invention.

FIG. 3 is a plan view showing another embodiment of the bag-shaped separator for a lead storage battery of the present invention.

FIG. 4 is a plan view showing another embodiment of the bag-type separator for a lead storage battery of the present invention.

FIG. 5 is a plan view showing another embodiment of the bag-type separator for a lead storage battery of the present invention.

FIG. 6 is a plan view showing another embodiment of the bag-type separator for a lead storage battery of the present invention.

FIG. 7 is a plan view of a conventional bag-shaped separator for a lead storage battery.

FIG. 8 is a plan view of a conventional bag-shaped separator for a lead storage battery.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 flat sheet 1S left and right side edges of flat sheet 2 rib 3 flat section 4 mini rib 5 bent gas discharge path 6 central section 7 linear gas discharge path 8 linear rib 9 linear gas discharge path 10 U-shaped rib 11 Straight rib 31 Straight rib 32 Gas discharge path 33 Mini rib 34 Sinusoidal rib 35 Bent gas discharge path

Continued on the front page (72) Inventor Yoshiaki Oishi 630 Tarui-cho, Fuwa-gun, Gifu Prefecture F-term in the Inorganic Corporation's Tarui Plant (reference) 5H021 CC09 CC11 CC12 CC18 EE04 HH03

Claims (5)

[Claims] 1. A lead-acid battery bag-like separator provided with a plurality of rows of ribs on at least one surface of a flat sheet, folded in two at its center, and fused at both left and right side edges,
The flat sheet is provided with ribs bent from the vertical bottom to the top as the ribs, thereby forming bent gas discharge paths between these ribs, and forming the bent at both side edges of the flat sheet. A bag-shaped separator for a lead storage battery, wherein a mini-rib having a height shorter than the rib is provided. 2. The bag-shaped separator for a lead-acid battery according to claim 1, wherein said bent ribs are formed by sinusoidal ribs. 3. The bag-shaped separator for a lead-acid battery according to claim 1, wherein a straight gas discharge path is formed between the bent ribs from the bottom to the top in the vertical direction. 4. At least two rows between the bent row of ribs and the row of mini-ribs extending vertically from bottom to top.
The bag-like separator for a lead-acid battery according to any one of claims 1 to 3, wherein a linear gas discharge path is formed between the linear ribs by providing at least two linear ribs. . 5. The bag-type separator for a lead-acid battery according to claim 4, wherein ribs are intermittently provided between the linear rib row and the bent rib row.