JPH0567463A - Sheet-like separator and sealed-type lead-acid battery - Google Patents

Abstract

PURPOSE:To prevent an electrolytic liquid from forming a layer and active material from dropping, improve the properties of a battery, and extend the life of the battery. CONSTITUTION:A sheet-like separator is used for a separator wherein the sheet- like separator has the flowing speed of an electrolytic liquid 100gum/hr or less and the value of the repellent at B point >=0.55Pkg/dm<2> and at C point >=0.40Pkg/dm<2> in the case Pkg/dm<2> at S point is assumed in the injected liquid repellent curve in the case of addition of a diluted sulfuric acid in the figure shown. An economical sealed-type lead-acid battery having excellent properties and a long life is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-shaped separator and a sealed lead-acid battery, and more particularly to a sheet-shaped separator and a sealed lead-acid battery which are less likely to cause stratification of an electrolytic solution and have a long life.

[0002]

2. Description of the Related Art A sealed lead-acid battery has a structure in which a separator and an electrode plate are stacked in a sealed container, and an electrolytic solution in the battery flows into the separator and the positive and negative electrode holes. Is held so that it never happens. This sealed lead-acid battery has features that it has excellent resistance to liquid leakage, does not require water replenishment, and has little self-discharge.

By the way, as described in Japanese Patent Publication No. Sho 63-27826, in a large-capacity sealed lead-acid battery having a high electrode plate, charging / discharging is performed even though the liquid is injected uniformly. When repeated, the concentration of the electrolytic solution held in the pores of the separator and the electrode plate becomes different in the vertical direction. That is, a stratification phenomenon occurs in which the electrolytic solution concentration increases toward the bottom of the separator. Since this stratification phenomenon is likely to occur mainly in the separator portion, in order to prevent this, increase the liquid holding power of the separator and make sure that there is no difference in liquid holding property between the top and the bottom of the separator or the electrolyte solution. It is required to increase the viscosity by adding fine silicic acid powder.

Conventionally, as the separator, one mainly made of glass fiber has been mainly used. In order to prevent the stratification phenomenon from occurring, various attempts have been made to improve the liquid retention property (liquid retention property) of the separator used.

For example, Japanese Patent Laid-Open Nos. 62-133669 and 62-136751 describe separators obtained by coating or mixing powders of SiO ₂ , TiO ₂ or rare earth element oxides. JP-A-63-152853,
No. 62-221954 and No. 61-269852 describe the use of silica or expanded perlite as powder. Further, JP-A-63-143742 and JP-A-63-146348 describe separators made of hollow thin tubular glass fibers.

The conventional improvement techniques represented by the above publications are as follows:
They are roughly classified into the following. Reduce the average fiber diameter of the glass fibers. Use organic fibers together. Silica powder is used together.

However, reducing the average fiber diameter of the glass fibers causes an increase in cost. Further, although the glass fiber separator can obtain good liquid absorption by the force of the capillary phenomenon, there is still a problem that the repulsion force at the time of liquid injection is lowered.

Further, when organic fibers are used together, impurities may be eluted into the liquid.

When the silica powder is used in combination, the separator density becomes large, the void ratio becomes small, and the liquid retention amount decreases, so that the battery capacity decreases. When silica powder is used in combination, it is easy to add silica powder to the electrolytic solution, but the process becomes complicated and the resulting battery becomes expensive, while silica is added to the separator. It is the current situation that mixed paper has not been put to practical use for the following reasons. That is, it is not possible to paper making as a separator with only silica powder, therefore, silica powder will be added to those mainly composed of glass fibers to mix paper,
If the proportion of silica powder is low, the effect of preventing the stratification phenomenon is low, and conversely, if the proportion of silica powder is high, papermaking becomes difficult.

As described above, conventionally, a sealed lead-acid battery separator which has an excellent effect of preventing the stratification phenomenon and is easy to manufacture has not been provided. Therefore, the conventional sealed lead-acid battery is stratified and has a short life.

As a solution to the above-mentioned conventional problems and to provide a sealed lead-acid battery with a long life and a low price, which is unlikely to cause stratification of the electrolyte, the present applicants have a flow rate of the electrolyte of 100 mm. We proposed a sealed lead-acid battery using a separator of less than 1 hour / hour and applied for a patent first (Japanese Patent Laid-Open No. 2-2
26654). Further, as a sealed lead-acid battery with long life and low price, which is less likely to cause stratification of the electrolytic solution, the present applicant has
A separator using a separator having an electrolytic solution flow rate of 100 mm / hour or less was found, and a patent application was previously filed (Japanese Patent Application No. 1-45584; hereinafter referred to as "prior application"). In practice, this prior separator is composed essentially of only glass fibers having an average fiber diameter of 0.65 μm or less, or
Alkali-containing glass fibers 95 to 3 having an average fiber diameter of 2 μm or less
0% by weight and specific surface area 100 m produced by the wet method
^{It is} substantially composed of 5 to 70% by weight of silica powder of ² / g or more.

[0012]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
According to No. 4, there is provided a sealed lead acid battery which is less likely to be stratified, has a long life and is inexpensive, but has the following further problems.

That is, when the pole group is set in the battery case and the electrolytic solution is injected, the internal pressure of the battery becomes smaller than the set pressure in the dry state. In this case, the softening rate of the anode active material is high, and the active material is likely to fall off. It is difficult for the separator and the electrode plate to come into close contact with each other, and a gap is created to reduce the battery capacity.As a result, the electrolytic solution flow rate is small, but as mentioned above, the liquid injection repulsion force is small, so the battery performance is not sufficiently improved. Not done. Such a problem occurs. Moreover, the cost is high in the separator according to the prior application, which is substantially composed of only ultrafine glass fibers having an average fiber diameter of 0.65 μm or less. On the other hand, in the separator in which silica powder is mixed, as described above, the hardness becomes too large in order to prevent the stratification phenomenon, which is not preferable.

Moreover, conventionally, there is no separator capable of absorbing a variation in the thickness of the electrode plate and ensuring a constant pressure, and the discharge characteristic (especially high rate discharge) is inferior or excessive if the pressure is too low. At present, it is difficult to insert the battery into the battery case under the tight pressure, and even if the battery container is swollen or cannot be inserted, the current situation occurs.

As described above, including the above-mentioned prior application, in the prior art, a separator for a sealed lead-acid battery, which has an excellent effect of preventing the stratification phenomenon, is easy to manufacture, and can maintain a certain pressure, and such a separator By using a separator,
No sealed lead acid battery has been provided that has improved battery performance, extended life, and is inexpensive.

The present invention solves the above-mentioned conventional problems, makes it difficult for the electrolyte to be stratified, and has a high effect of preventing the softening of the active material.
An object of the present invention is to provide a sheet-shaped separator capable of providing a long-life and inexpensive sealed lead acid battery and a sealed lead acid battery using the same.

It is another object of the present invention to provide a sheet-shaped separator in which stratification of an electrolytic solution does not easily occur and a constant pressure is ensured, and a sealed lead-acid battery using the same.

[0018]

The sheet-like separator according to claim 1 has an electrolyte flow rate of 100 mm / hr.
In the following sheet-like separator, in the liquid repulsion force curve when dilute sulfuric acid is injected shown in FIG. 1, when the value of the repulsion force is S point = Pkg / dm ² , B point ≧ 0.55 Pkg / It is characterized in that dm ² C point ≧ 0.40 Pkg / dm ² .

The sheet-shaped separator according to claim 2 is the same as the separator according to claim 1, wherein the flow rate of the electrolytic solution is 80 mm.
/ Hr or less.

A sheet-shaped separator according to a third aspect is the separator according to the first or second aspect, characterized in that it is substantially composed of only glass fibers.

The sheet-shaped separator according to claim 4 is the same as the separator according to claim 3, wherein the average fiber diameter is 0.4 to 0.7 μm.
40 to 60% by weight of fine glass fibers having an average fiber diameter of 0.
20% by weight or less of medium and small diameter glass fibers exceeding 7 μm and less than 1.1 μm, 60 to 40% by weight of medium and large diameter glass fibers 1.1 to 5.0 μm, and average fiber diameter 5.0 μm
It is characterized in that it is substantially composed of 15% by weight or less of large-diameter glass fiber having a diameter of more than 30 μm.

The sheet-shaped separator according to claim 5 is the separator according to claim 4, wherein the average fiber diameter is 0.50 to 0.6.
44 to 56% by weight of thin glass fibers of 5 μm, 10% by weight or less of medium-to-fine glass fibers having an average fiber diameter of more than 0.65 μm and less than 2.0 μm, medium-to-large glass of an average fiber diameter of 2.0 to 4.5 μm 44 to 56% by weight of fiber, and average fiber diameter 4.
10% by weight of large-diameter glass fiber of more than 5 μm and 30 μm or less
It is characterized in that it is substantially configured as follows.

A sheet-shaped separator according to a sixth aspect is characterized in that, in the separator according to the first to third aspects, a part or all of the glass fiber is subjected to a water repellent treatment.

A sheet-shaped separator according to a seventh aspect is the separator according to the sixth aspect, wherein the water repellent treatment is performed by a silane coupling agent.

The sheet-like separator according to claim 8 is the separator according to claim 7, wherein the water-repellent treated glass fiber has an average adhesion ratio of the silane coupling agent to the glass fiber of 0.01 to 4.0% by weight. Is characterized by.

The sheet-shaped separator according to claim 9 is the separator according to claim 7 or 8, characterized in that the proportion of the glass fiber treated to be water-repellent is 5 to 100% by weight based on the glass fiber constituting the separator. And

The sheet-shaped separator according to claim 10 is characterized in that, in the separator according to claims 6 to 9, the average fiber diameter of the glass fibers is 2 μm or less.

The sheet-like separator according to claim 11 is the separator according to any one of claims 6 to 9, wherein the glass fibers are thin glass fibers having an average fiber diameter of 2 μm or less and an average fiber diameter of 2 μm.
It is characterized in that it is composed of large-diameter glass fibers exceeding m, and part or all of the small-diameter glass fibers and / or the large-diameter glass fibers are water-repellent treated.

The sheet-shaped separator according to claim 12 is the separator according to any one of claims 6-10, having an average fiber diameter of 0.4-.
40 to 60% by weight of fine glass fibers of 0.7 μm, 20% by weight or less of medium and fine glass fibers having an average fiber diameter of more than 0.7 μm and less than 1.1 μm, and an average fiber diameter of 1.1 to 5.0 μm It is characterized in that it is substantially composed of 60 to 40% by weight of glass fiber having a diameter and 15% by weight or less of a large glass fiber having an average fiber diameter of more than 5.0 μm and 30 μm or less.

The sheet-shaped separator according to claim 13 is the separator according to claim 12, which has an average fiber diameter of 0.50 to 0.50.
44 to 56% by weight of fine glass fibers having a diameter of 0.65 μm, 10% by weight or less of medium to fine glass fibers having an average fiber diameter of more than 0.65 μm and less than 2.0 μm, and an average fiber diameter of 2.0 to 4.5 μm
44 to 56% by weight of medium- and large-diameter glass fibers, and large-diameter glass fibers 10 having an average fiber diameter of more than 4.5 μm and 30 μm or less
It is characterized in that it is substantially constituted by not more than wt%.

The sheet-shaped separator according to claim 14 is characterized in that, in the separator according to claim 1 or 2, it is substantially composed of organic fibers and glass fibers.

The sheet-shaped separator according to claim 15 is the separator according to claim 14, in which the organic fiber has an average fiber diameter of 2
It is characterized in that it is a polypropylene fiber having a mean fiber length of 2 to 25 mm and a length of -20 μm.

The sheet-like separator according to claim 16 is the separator according to claim 14 or 15, wherein the organic fibers 7 to 3 are used.
It is characterized by being substantially composed of 5% by weight and 93 to 65% by weight of glass fiber.

The sheet-shaped separator according to claim 17 is characterized in that, in the separators according to claims 14 to 16, the average fiber diameter of the glass fibers is 2 μm or less.

The sheet-like separator according to claim 18 is the separator according to any one of claims 14 to 16, wherein the glass fibers are glass fibers having an average fiber diameter of 2 μm or less and an average fiber diameter of 2 μm.
It is characterized in that it is composed of a glass fiber that exceeds.

A sheet-like separator according to claim 19 is the separator according to any one of claims 14 to 16, wherein the glass fibers are thin glass fibers 4 having an average fiber diameter of 0.4 to 0.7 μm.
0-60% by weight, average fiber diameter exceeds 0.7 μm and 1.1 μ
20% by weight or less of medium and small diameter glass fibers less than m, 60 to 40% by weight of medium and large diameter glass fibers having an average fiber diameter of 1.1 to 5.0 μm, and a large diameter of more than 5.0 μm and 30 μm or less. It is characterized by being composed of 15% by weight or less of glass fiber.

A sheet-like separator according to claim 20 is the separator according to claim 19, wherein the glass fibers are thin glass fibers 44 to 56 having an average fiber diameter of 0.50 to 0.65 μm.
% By weight, average fiber diameter more than 0.65 μm and less than 2.0 μm, medium to small diameter glass fiber 10% by weight or less, average fiber diameter 2.0
.About.4.5 .mu.m medium to large diameter glass fibers 44 to 56% by weight, and 10% by weight or less of large diameter glass fibers having an average fiber diameter of more than 4.5 .mu.m and 30 .mu.m or less.

A sheet-shaped separator according to a twenty-first aspect is characterized in that, in the separator according to the first aspect, it is mainly composed of glass fibers and contains 0.5 to 5.0% by weight of polyethylene powder.

The sheet-shaped separator according to claim 22 is the separator according to claim 21, wherein the glass fibers are 25 to 60% by weight of fine glass fibers having an average fiber diameter of 0.4 to 0.7 μm and an average fiber diameter of 0.7 μm. 0 to 20% by weight of medium- and small-diameter glass fibers having an average fiber diameter of 1.1 to 5.
It is characterized by being composed of 75 to 40% by weight of medium and large diameter glass fibers of 0 μm and 0 to 15% by weight of large diameter glass fibers having an average fiber diameter of more than 5.0 μm and 30 μm or less.

The sheet-like separator according to claim 23 is the separator according to claim 22, wherein the glass fibers are thin glass fibers 24 to 56 having an average fiber diameter of 0.50 to 0.65 μm.
% By weight, average fiber diameter more than 0.65 μm and less than 2.0 μm, medium to small diameter glass fiber 0 to 10% by weight, average fiber diameter 2.0
.About.4.5 .mu.m medium to large diameter glass fibers 71 to 36% by weight and 0 to 10% by weight large diameter glass fibers having an average fiber diameter of more than 4.5 .mu.m and not more than 30 .mu.m.

The sealed lead-acid battery of claim 24 is the same as that of claim 1.
23. The sheet-like separator according to any one of items 23 to 23 is used.

The present invention will be described in detail below. First, the principle of the liquid injection repulsive force curve shown in FIG. 1 will be described. Figure 1
In, the horizontal axis represents the liquid saturation and the vertical axis represents the repulsion force.

When the electrolytic solution is gradually added (every 2 minutes) under a constant load of the fine glass fiber mat, the locus shown in FIG. 1 is obtained. The points A, B, and C of this curve are moved up and down by changing the diameter of the glass fiber forming the glass fiber mat.

Locus from point S to point B It goes down due to contraction of the separator. Locus from point B to point A due to expansion of the fine glass fiber mat. At point A, the liquid saturation is almost 100%. Trajectory from point A to point C Due to re-contraction of the separator. The principle is similar to the locus of S point → B point (however, the positions of B point and C point are always B point> C point). The repulsion force can be measured in a short time (every 2 minutes) by the method of measuring the displacement between the points B and C.
Since it is done in, because the repulsion force is measured before the electrolytic solution after injection is uniformly diffused in the fine glass fiber mat,
A phenomenon such as point B> point C occurs.

The sheet-shaped separator of the present invention is a separator in which the flow rate of the electrolytic solution is 100 mm / hr or less.
When the flow rate of the electrolytic solution exceeds 100 mm / hr, the electrolyte retaining capacity is small, so that the so-called stratification phenomenon in which the electrolytic solution concentration changes in the vertical direction of the separator when charging and discharging are repeated becomes remarkable. From the viewpoint of preventing the stratification phenomenon, it is preferable that the flow rate of the electrolytic solution be smaller,
If it is too small, it will take a long time to inject. Therefore, in the separator used for the sealed lead acid battery of the present invention, the flow rate of the electrolytic solution is 80 mm / hr or less, preferably 5 to 80 mm / hr, more preferably 20 to 70.
It is good that it is mm / hr.

In the present invention, the repelling force of the sheet-like separator and the flow rate of the electrolytic solution can be determined by the methods described in Examples below.

The sheet-like separator of the present invention can employ the following modes. (1) Those composed only of glass fibers. (2) A glass fiber that is made of only glass fiber and is partially water repellent. (3) Those composed of organic fibers and glass fibers. (4) Those composed of glass fiber and polyethylene powder.

In the case of the above (1), if the glass fiber diameter is small, the liquid flow-down velocity is small, but on the other hand, the liquid repelling force is small. On the contrary, if the glass fiber diameter is large, the liquid repelling force is large, but the liquid flow rate becomes large. Therefore, in order to satisfy the liquid flow rate and the liquid repulsion force specified in the present invention, it is necessary to combine the glass fiber diameters, and the following fiber blend I, more preferably fiber blend II, is preferable.

Fiber Blend I Fine glass fiber having an average fiber diameter of 0.4 to 0.7 μm: 40
-60 wt% Medium-fine glass fiber with an average fiber diameter of more than 0.7 μm and less than 1.1 μm: 20% by weight or less Medium-large glass fiber with an average fiber diameter of 1.1-5.0 μm: 6
0 to 40% by weight Large diameter glass fibers having an average fiber diameter of more than 5.0 μm and 30 μm or less: 15% by weight or less Fiber blend II Fine glass fibers having an average fiber diameter of 0.50 to 0.65 μm:
44 to 56% by weight Medium fiber glass fiber having an average fiber diameter of more than 0.65 µm and less than 2.0 µm: 10% by weight or less Medium to large diameter glass fiber having an average fiber diameter of 2.0 to 4.5 µm: 4
4 to 56 wt% Large-diameter glass fiber having an average fiber diameter of more than 4.5 μm and 30 μm or less: 10 wt% or less In the case of (2) above, the water repellent treatment is preferably performed by a silane coupling agent. The average adhesion ratio of the silane coupling agent to the glass fiber of the treated glass fiber is 0.01 to 4.0% by weight, particularly 0.05 to 2.
It is preferably 0% by weight, and the proportion of the glass fiber treated to be water-repellent is preferably 5 to 100% by weight based on the glass fiber constituting the separator. The silane coupling agent firmly adheres to the glass fiber surface and makes the surface water repellent. Therefore, the liquid repelling force can be increased and the liquid flow rate can be reduced. If the degree of water repellent treatment is outside the above range, such effects may not be sufficiently achieved. Since silane has a remarkably high adhesion to the glass fiber surface, it hardly elutes into the electrolytic solution, which is extremely advantageous.

In the aspect of (2), the glass fiber has a constitution in which (A) the glass fiber has an average fiber diameter of 2 μm or less. The glass fiber (B) is composed of thin glass fibers having an average fiber diameter of 2 μm or less and large glass fibers having an average fiber diameter of more than 2 μm. (C) The glass fiber is composed of the above-mentioned fiber blend I, preferably fiber blend II. In the cases of (B) and (C), the fiber diameter of the glass fiber to be water repellent is not particularly limited, and at least one of the small diameter and the large diameter glass fiber, the small diameter and the medium diameter. At least one of thin, medium and large diameter glass fibers
The seed can be water repellent.

In this case, a small amount of other substances, which are harmless to the battery, may be mixed as a reinforcing material (JP-A-64-523).
No. 75).

In the above aspect (3), the organic fibers have an average fiber diameter of 2 to 20 μm and an average fiber length of 2 to 2
5 mm polypropylene fiber is preferable, and organic fiber 7-
It is preferably composed substantially of 35% by weight and 93 to 65% by weight of glass fiber.

That is, polypropylene fiber has high water repellency and is effective in the present invention. If the average fiber diameter of polypropylene fiber is less than 2 μm, it is expensive, and if it exceeds 20 μm, the effect is small. If the average fiber length is less than 2 mm, the cutting cost is high and the practicality is low, and if it exceeds 25 mm, the dispersibility is deteriorated. The organic fiber content is 7% by weight.
If it is less than 35% by weight, the effect is small, and if it exceeds 35% by weight, the liquid retaining property becomes poor.

Also in the aspect of (3), the glass fiber constitutions of the above (A) to (C) can be adopted as the glass fiber constitution.

In the above aspect (4), the polyethylene powder preferably has an average particle size of 2 to 10 μm. If the average particle size of the polyethylene powder is less than 2 μm, the cost will be high, and if it exceeds 10 μm, the effect of reducing the liquid flow rate will be small, and either case is not preferable.

The proportion of such polyethylene powder is 0.
If it is less than 5% by weight, a sufficient effect due to the mixing of polyethylene powder cannot be obtained, and if it exceeds 5.0% by weight, the amount of polyethylene powder is too large and the electrolytic solution is difficult to penetrate into the separator. Therefore, the proportion of polyethylene powder in the separator is 0.5 to 5.0% by weight.

Since the polyethylene powder is hydrophobic, it is possible to effectively reduce the flow rate of the electrolytic solution in the separator by mixing the polyethylene powder. Therefore, the stratification phenomenon of the separator is prevented.

Further, the polyethylene powder has a function of weakening the adhesion between the glass fibers, so that the separator becomes soft and rich in flexibility. Therefore, it is possible to secure a constant tension.

Moreover, by using polyethylene powder, it becomes possible to secure the required characteristics without using glass fibers having a small diameter. Therefore, it is possible to provide the separator at low cost by using glass fibers having a relatively large diameter.

For this reason, the glass fibers can be compounded in a larger proportion of the glass fibers having a relatively larger diameter than the above-mentioned fiber compounds I and II. For example, the following fiber compound III, preferably fiber compound IV, is used. , Average fiber diameter 1.1 to 5.0 μm
The ratio of medium to large diameter glass fibers can be increased.

Fiber Blend III Fine glass fiber having an average fiber diameter of 0.4 to 0.7 μm: 25
-60% by weight Medium to medium diameter glass fibers with an average fiber diameter of more than 0.7 µm and less than 1.1 µm: 0 to 20% by weight Medium to large diameter glass fibers with an average fiber diameter of 1.1 to 5.0 µm: 7
5-40% by weight Large diameter glass fibers having an average fiber diameter of more than 5.0 μm and 30 μm or less: 0-15% by weight Fiber blend IV Fine glass fibers having an average fiber diameter of 0.50-0.65 μm:
24 to 56% by weight Medium to medium diameter glass fibers with an average fiber diameter of more than 0.65 μm and less than 2.0 μm: 0 to 10% by weight Medium to large diameter glass fibers with an average fiber diameter of 2.0 to 4.5 μm: 7
1-36% by weight Large diameter glass fiber having an average fiber diameter of more than 4.5 μm and not more than 30 μm: 0-10% by weight According to the separator of the aspect of (4), in the measuring method in Examples described below, It is possible to secure various characteristics.

Electrolyte flow rate: 100 mm / hour or less Apparent density / compression pressure: 1.3 × 10 ⁻⁴ or more 20 kg / dm ² Pressurized density: 0.165 g / cm ³ or less Tensile strength: 200 g / 15 mm width Above liquid retention: 0.6 g / cc or more Liquid absorption: 50 mm / 5 minutes or more Since the glass fiber used in the present invention is used in a storage battery among alkali-containing silicate glass fibers, Those having good acid resistance are preferably used. The degree of acid resistance is preferably 2% or less in weight loss when measured according to JIS C-2202 in the state of glass fibers having an average fiber diameter of 1 μm or less. Further, the composition of such glass fiber is 60 to 75% by weight of SiO.
₂ and 8 to 20% of R ₂ O (alkali metal oxides such as Na ₂ O and K ₂ O) is mainly contained (provided that SiO ₂
+ R ₂ O is 75 to 90%), and other components such as CaO and M
Examples thereof include those containing one or more of gO, B ₂ O ₃ , Al ₂ O ₃ , ZnO, Fe ₂ O _{3 and the} like. An example of a preferable alkali silicate glass is shown in Table 1 below.

[0063]

[Table 1]

To manufacture the separator of the present invention, for example, the following method is advantageous. That is, glass fibers having a relatively short length, which are manufactured by FA method (flame method), centrifugal method and other glass short fiber manufacturing methods, are prepared, and disintegrated, cut and dispersed with a pulper. Alternatively, the glass fiber may be cut into short pieces by an appropriate cutting means while the glass fiber is being supplied to the paper machine net.

The cut glass fibers and polyethylene powder (in the above-mentioned embodiment (4)) are paper-made on a net. This wet-processed glass fiber papermaking product is generally dried along a drum or a dryer to obtain a product.

A dispersant may be used when the fibers are dispersed in water during the papermaking. Further, a dialkyl sulphosuccinate is sprayed onto a wet-processed fiber paper product, for example, a fiber paper product on a papermaking net, so that 0.005 to 10% by weight of the dialkyl sulphosuccinate is attached to the glass fiber. The hydrophilicity of succinate can improve the liquid retention of the separator. Instead of spraying the dialkyl sulfosuccinate as described above, it may be mixed in the dispersion water in the paper making tank.

The thickness of the separator of the present invention is not particularly limited, but it is preferable that the thickness is equal to or larger than the average fiber length of glass fibers.

The sealed lead-acid battery of the present invention can be easily produced by using the separator of the present invention as described above according to a conventional method.

[0069]

EXAMPLES Examples and comparative examples will be described below.
The methods of measuring the flow rate of the electrolytic solution, the repelling force of the electrolytic solution, the battery life cycle, the tensile strength, the liquid absorbing property, the liquid retaining property, the thickness and the basis weight in Examples and Comparative Examples are as follows.

Flow Rate of Electrolyte The sample is cut into a size of 50 mm × 250 mm. Two acrylic plates (width 70 to 8) placed oppositely at both ends with spacers so that the weight of the sample is about 6.75 g (filling density 0.16 to 0.21 g / cm ³ ).
0 mm x length 500 mm). Soak the sample in water. The wet sample is set on the measuring jig. Gently inject a sulfuric acid solution with a specific gravity of 1.3 from above the acrylic plate with a pipette. The sulfuric acid solution is injected 100 mm from the top of the sample, and the solution is added as needed to keep the height constant. The sulfuric acid solution is colored with red ink or methyl orange in advance. 5 minutes, 10 minutes, 30 minutes after adding the electrolyte
The drop distance after 60 minutes is measured with a steel scale. Accurately measure the time with a stopwatch. The measurement is performed three times for each sample.

Liquid Injection Repulsion Force The repulsion force tester shown in FIG. 2 was used to measure as follows. (1) 30 samples (100 mm x 100 mm) (10
Cut one set). (2) The weight of one set of sample 1 is measured. (3) First, perform a preliminary experiment.

Preliminary Experimental Procedure: Sample 1 was placed on a repulsion tester, handle 2 was turned to compress sample 1, the compressive force was detected by load cell 3, read by pressure gauge 4, and set at 40 kg / m ² pressure. To do. After setting, water 5 is gradually added from the top of the sample 1 and it is confirmed how many cc of water should come out from the side of the sample. The amount of liquid when water comes out from the side is (W).

(4) After the completion of the preliminary experiment, the sample is put on the repulsion tester and set again to the pressure of 40 kg / m ² . (After setting, adjust the pressure again to 40 kg every 1 minute, and
(It should be 40 kg even after a minute.) (5) After setting, measure the thickness of the sample at four points with a caliper. (6) Add 10 g of water each and measure the change in pressure after 2 minutes. (7) Perform the same measurement as in (6) by halving the amount of water input to 5 g from around 20 g of water (preliminary experiment value) -20 g. (8) Next, absorb excess water (water that the sample cannot absorb) with a dropper and a syringe, and measure and record the amount of absorbed water. (9) Finally, absorb water in the sample with a syringe. (10) The operation of (9) is to be performed finely until the pressure does not change. (11) Measurement shall be performed twice or more. (12) The results are shown as S, B, and C points in the graph of FIG. 1, which are change rates when the starting pressure is set to 1.

Battery Life Cycle A sealed lead acid battery was assembled using various separators. The assembled sealed lead-acid battery has a width of 40 mm and a height of 7
0 mm × 3.3 mm thick two positive electrode plates and a negative electrode plate having the same size and a thickness of 2.0 mm are laminated through a predetermined separator under a pressure of 20 kg / dm ² . 43 cc of H ₂ SO ₄ with a specific gravity of 1.30 was injected per cell, and the capacity per cell was 5 Ah / 20HR. The battery thus assembled was subjected to an alternating charge / discharge life test with one cycle of "discharge at 1.4A for 3 hours and charge at 1.02A for 5 hours". The battery capacity is 4.2 Ah (= 1.
4A × 3 h) or less was defined as the life.

Tensile strength : Both ends of a sample having a width of 15 mm are pulled, and the value (g) of external force when the sample is cut is displayed.

It is determined by making the liquid-absorbent sample vertical and immersing the lower part in a dilute sulfuric acid solution having a specific gravity of 1.03, and measuring the liquid level rising for 5 minutes.

Liquid retention property The weight and thickness of the sample are measured in advance. Immerse this in a band filled with water for 30 seconds and then pull it up on a tilting table, 45 °
After holding for 5 minutes, the weight of the sample is measured and the liquid retention is determined by the following formula. Liquid retention (g / cc) = (W ₂ −W ₁ ) / l × W × t W ₁ : Sample weight before immersion (g) W ₂ : Sample weight after immersion (g) l: Length 25 cm W : Width (cm) 5 cm t: Actual thickness of sample (cm) Apparent density / Pressure pressure 60 kg / dm ² Apparent density D ₆₀ and 10 kg / d at pressurization
₂ A value obtained by dividing the difference from the apparent density D ₁₀ under pressure by 50 kg / dm ² (D ₆₀ −D ₁₀ ) / 50, that is, (apparent density / compression pressure).

This is a value obtained by dividing the weight of the weighted sample by the sample area.

The thickness of the sample is measured while being pressed with a load of 20 kg / dm ^{2 in} the thickness direction. (JISC-2202) Examples 1 and 2 and Comparative Examples 1 to 5 Sheet-shaped separators having liquid flow-down speeds and liquid-repellent repulsion values shown in Table 2 were produced, and their battery life cycles were examined. The results are shown in Table 2. Indicated.

[0080]

[Table 2]

Examples 3 to 5 and Comparative Examples 6 to 11 Various physical properties and characteristics of the glass fiber-containing separators shown in Table 3 were examined, and the results are shown in Table 3.

[0082]

[Table 3]

Example 6 With respect to a glass fiber compounding system having an average fiber diameter shown in FIG. 3 below, the liquid flow rate and the liquid repulsion force (point B) were examined, and the results are shown in FIG. In FIG. 3, the solid line shows the results of the blending system of glass fibers having an average fiber diameter of 0.6 μm and 2.0 μm, and the broken line shows the results of the blending system of glass fibers having an average fiber diameter of 0.6 μm and 4.0 μm. From FIG. 3, it is clear that the blending range of α is suitable.

From Table 3, as shown in Example 5, when a small amount of glass fiber having a large diameter exceeding 30 μm and having an average fiber diameter of 5 μm is mixed, the cost can be reduced, but the fiber has a large diameter and the fiber itself. Since its flexibility is low, if it is mixed in too much, as in Comparative Example 11, both the liquid flow rate and the liquid repulsion force become poor. Therefore, 15% by weight or less, preferably 10% by weight.
Must be:

Examples 7 to 23, Comparative Examples 12 to 14 Various characteristics were examined for the separators containing the following glass fibers in the formulations shown in Tables 4 to 6, and the results are shown in Tables 4 to 6.

[0086]

[Table 4]

[0087]

[Table 5]

[0088]

[Table 6]

Examples 24 and 25, Comparative Examples 15 to 20 Various characteristics of the fiber-blended separators shown in Table 7 were examined, and the results are shown in Table 7. The organic fibers used are as follows.

Polypropylene fiber = average fiber diameter 8 μm average fiber length 5 mm Polyethylene fiber = average fiber diameter 8 μm average fiber length 2 mm Polyester fiber = average fiber diameter 7 μm average fiber length 5 mm

[0091]

[Table 7]

Examples 26 to 29, Comparative Examples 21 to 26 Various characteristics of the fiber-blended separators shown in Table 8 were examined, and the results are shown in Table 8.

[0093]

[Table 8]

Examples 30 to 37, Comparative Examples 27 to 34 Storage battery separators were manufactured with the material formulations shown in Tables 9 and 10, and the measurement results of various characteristics are shown in Tables 9 and 10. Further, the results of comprehensive evaluation from the measurement results of the respective characteristics are shown in Table 9 and Table 10 as x = not good and ◯ = good.

[0095]

[Table 9]

[0096]

[Table 10]

The following is clear from Tables 9 and 10. That is, the separator of the aspect (4) of the present invention is excellent in the anti-stratification effect, and thus is excellent in the life performance, particularly the alternate charge / discharge life performance. Further, the liquid retaining property is remarkably high, and the apparent density / tension is 1.3 × 10 ⁻⁴ or more, and it is easy to incorporate in a sealed lead acid battery case. The larger the apparent density / tension is, the more elastic it is, the easier it is to compress when it is put in the battery case, and the better the pressing force after it is put in it. In this way, since this separator is soft and rich in elasticity, the pressure is absorbed even if the number of plates is large, and it is easy to put the separator in the case of the sealed lead acid battery, and the pressure varies. Never.

[0098]

As described above in detail, the sheet-shaped separator of the present invention has a remarkably high liquid retaining property of the electrolytic solution, and the liquid retaining properties in the vertical direction of the separator are equalized, and the stratification phenomenon and the activity are suppressed. Since the material is prevented from softening, it has an extremely long life performance.

Therefore, not only the small capacity sealed lead acid battery but also the large capacity sealed lead acid battery having a high electrode plate can be stable and have a long battery life. It is clear that this extended life exhibits long life performance not only in the alternating charge and discharge as tested but also in the floating charge application.

According to the sheet-like separators of claims 4 to 20, a sheet-like separator having a particularly low electrolytic solution flow-down speed and a high liquid-repelling force is provided.

In particular, the sheet-like separators according to claims 21 to 23 are soft and rich in elasticity, and therefore can be easily incorporated in a battery case. Also, the tension is constant. Moreover, this separator can be composed mainly of glass fibers having a relatively large diameter, and it is possible to reduce the cost of the separator and to provide an inexpensive sealed lead-acid battery excellent in manufacturing workability.

According to the sealed lead-acid battery of claim 24, a sealed lead-acid battery having a long life, a low price and excellent battery performance is provided.

[Brief description of drawings]

FIG. 1 is a graph showing a liquid injection repulsive force curve.

FIG. 2 is a diagram illustrating a measuring device for liquid repulsion force.

FIG. 3 is a graph showing the results of Example 5.

[Explanation of symbols]

 1 Sample 2 Handle 3 Load cell 4 Pressure gauge 5 Water

Front Page Continuation (72) Inventor Shoji Sugiyama 3-5-11 Doshomachi, Chuo-ku, Osaka City, Osaka Prefecture Nippon Sheet Glass Co., Ltd. (72) Instructor Yasuhide Nakayama 6-6 Josaimachi, Takatsuki City, Osaka Yuasa Battery Co., Ltd. Inside the formula company (72) Inventor Katsumi Kitagawa 6-6 Josaimachi, Takatsuki-shi, Osaka Yuasa Battery Co., Ltd. Inside the company (72) Kenjiro Kishimoto 6-6 Josaimachi, Takatsuki-shi, Osaka Yuasa Battery Co.

Claims (24)

[Claims] 1. A sheet-shaped separator having an electrolytic solution flow rate of 100 mm / hr or less, wherein the repulsive force value in the injection repulsion curve when dilute sulfuric acid is injected shown in FIG. sheet separator, characterized in that when a point B ≧ 0.55Pkg / dm ² C point ≧ 0.40Pkg / dm ² to pkg / dm ^2. 2. The sheet-shaped separator according to claim 1, wherein the flow rate of the electrolytic solution is 80 mm / hr or less. 3. The sheet-shaped separator according to claim 1, which is substantially composed of only glass fibers. 4. A small glass fiber having an average fiber diameter of 0.4 to 0.7 μm, 40 to 60% by weight, an average fiber diameter of more than 0.7 μm and less than 1.1 μm, 20% by weight or less,
Medium to large diameter glass fiber 60 having an average fiber diameter of 1.1 to 5.0 μm
-40% by weight and average fiber diameter exceeding 5.0 μm 30
The sheet-shaped separator according to claim 3, which is substantially composed of 15% by weight or less of a large-diameter glass fiber having a diameter of μm or less. 5. Fine glass fibers having an average fiber diameter of 0.50 to 0.65 μm, 44 to 56% by weight, and an average fiber diameter of 0.65 μm.
10% by weight of medium- and small-diameter glass fibers exceeding m and less than 2.0 μm
In the following, 44 to 56% by weight of medium to large diameter glass fibers having an average fiber diameter of 2.0 to 4.5 μm and 10% by weight or less of large diameter glass fibers having an average fiber diameter of more than 4.5 μm and 30 μm or less are substantially constituted. The sheet-shaped separator according to claim 4. 6. The sheet-shaped separator according to claim 1, wherein at least a part of the glass fiber is subjected to a water repellent treatment. 7. The sheet-shaped separator according to claim 6, wherein the water-repellent treatment is performed with a silane coupling agent. 8. The average adhesion ratio of the silane coupling agent to the glass fiber of the water-repellent glass fiber is 0.01 to.
The sheet-shaped separator according to claim 7, which is 4.0% by weight. 9. The water-repellent treated glass fiber is contained in an amount of 5 to 100% by weight based on the glass fiber constituting the separator.
The sheet-shaped separator according to claim 7 or 8. 10. The sheet-shaped separator according to claim 6, wherein the average fiber diameter of the glass fibers is 2 μm or less. 11. The glass fiber is composed of a small diameter glass fiber having an average fiber diameter of 2 μm or less and a large diameter glass fiber having an average fiber diameter of more than 2 μm, and a small diameter glass fiber and / or a part of the large diameter glass fiber or The entire surface is treated to be water repellent.
10. The sheet-shaped separator according to any one of items 1 to 9. 12. A thin glass fiber having an average fiber diameter of 0.4 to 0.7 μm, 40 to 60% by weight, an average fiber diameter of more than 0.7 μm and less than 1.1 μm, 20% by weight or less, of an average diameter. It is substantially composed of medium to large diameter glass fibers 60 to 40% by weight having a fiber diameter of 1.1 to 5.0 μm, and large diameter glass fibers 15% by weight or less having an average fiber diameter of more than 5.0 μm and 30 μm or less. The sheet-shaped separator according to claim 6. 13. Fine glass fibers having an average fiber diameter of 0.50 to 0.65 μm, 44 to 56% by weight, and an average fiber diameter of 0.65.
10 to 10% by weight of medium- and small-diameter glass fibers exceeding μm and less than 2.0 μm, 44 to 56% by weight of medium- and large-diameter glass fibers having an average fiber diameter of 2.0 to 4.5 μm, and exceeding 4.5 μm of average fiber diameter The sheet-shaped separator according to claim 12, which is substantially composed of 10% by weight or less of a large-diameter glass fiber having a diameter of 30 μm or less. 14. The sheet-shaped separator according to claim 1, which is substantially composed of organic fibers and glass fibers. 15. The organic fiber has an average fiber diameter of 2 to 20 μm.
The sheet-shaped separator according to claim 14, which is a polypropylene fiber having an average fiber length of 2 to 25 mm. 16. The sheet-shaped separator according to claim 14, which is substantially composed of 7 to 35% by weight of organic fibers and 93 to 65% by weight of glass fibers. 17. The sheet-like separator according to claim 14, wherein the average fiber diameter of the glass fibers is 2 μm or less. 18. The sheet-shaped separator according to claim 14, wherein the glass fibers are composed of glass fibers having an average fiber diameter of 2 μm or less and glass fibers having an average fiber diameter of more than 2 μm. 19. The glass fiber has an average fiber diameter of 0.4 to
40 to 60% by weight of fine glass fibers of 0.7 μm, 20% by weight or less of medium and fine glass fibers having an average fiber diameter of more than 0.7 μm and less than 1.1 μm, and an average fiber diameter of 1.1 to 5.0 μm The sheet-shaped separator according to any one of claims 14 to 16, which comprises 60 to 40% by weight of glass fibers having a diameter of 15% by weight or less and glass fibers having a diameter of more than 5.0 µm and not more than 30 µm and having an average diameter of 30 µm or less. . 20. The glass fiber has an average fiber diameter of 0.50 to 50.
44 to 56% by weight of fine glass fibers having a diameter of 0.65 μm, 10% by weight or less of medium to fine glass fibers having an average fiber diameter of more than 0.65 μm and less than 2.0 μm, and an average fiber diameter of 2.0 to 4.5 μm
44 to 56% by weight of medium- and large-diameter glass fibers, and large-diameter glass fibers 10 having an average fiber diameter of more than 4.5 μm and 30 μm or less
The sheet-shaped separator according to claim 19, wherein the sheet-shaped separator is composed of not more than wt%. 21. The sheet-like separator according to claim 1, which is composed mainly of glass fibers and contains 0.5 to 5.0% by weight of polyethylene powder. 22. The glass fiber has an average fiber diameter of 0.4 to
25 to 60% by weight of 0.7 μm thin glass fiber, medium fiber diameter of more than 0.7 μm and less than 1.1 μm, medium to thin glass fiber 0 to 20% by weight, average fiber diameter of 1.1 to 5.0 μm 75-40% by weight of large-diameter glass fibers, and 0-1 large-diameter glass fibers having an average fiber diameter of more than 5.0 μm and 30 μm or less
22. The sheet-shaped separator according to claim 21, which is composed of 5% by weight. 23. The glass fiber has an average fiber diameter of 0.50 to 50.
24 to 56% by weight of fine glass fibers of 0.65 μm, 0 to 10% by weight of medium and fine glass fibers having an average fiber diameter of more than 0.65 μm and less than 2.0 μm, an average fiber diameter of 2.0 to 4.5 μm
71 to 36% by weight of medium- and large-diameter glass fibers, and 0 to 30 μm of large-diameter glass fibers having an average fiber diameter of more than 4.5 μm and not more than 30 μm
The sheet-shaped separator according to claim 22, which is composed of 10% by weight. 24. A sealed lead acid battery using the sheet-like separator according to any one of claims 1 to 23.