JPS6351044A - Manufacture of separator for storage battery - Google Patents

Abstract

PURPOSE:To make it possible to form a grid block form separator efficiently, by forming recessed lines longitudinally to a plain sheet-form product of a material mainly of a glass fiber, superposing the sheet-form products with the recessed lines each other, or such a sheet-form product and a plain product together, and joining them. CONSTITUTION:A sheet-form product 1 is made by a wet manufacture with a material mainly of a glass fiber, and such a product is pressed by rollers 2, after removing the moisture and before heat-drying, to form recessed lines 3 with a specific section form, extending longitudinal to the sheet-form product 1. The sheet form products 4 and 4' with the recessed lines 3 are half-dried at a degree necessary to maintain the forms, spreading adhesive at the contacting surfaces, and superposing facing the recessed lines 3 and 3' each other, and then heat-dried again while squeezing them to attach each other. By attaching the sheet-form products 4 and 4', a grid block 6 with spaces 5 of round sections is obtained, and by cutting the product in a specific length, a separator for a storage battery can be produced.

Description

Detailed Description of the Invention [A] The present invention relates to a method for manufacturing a separator for a storage battery, and in particular, an industrially advantageous method for manufacturing a separator for a storage battery useful for sealing a clad type battery. Regarding.

[Prior Art] Paste-type electrode plates and clad-type electrode plates have been known as types of anodes for storage batteries, and the latter has the advantage of having a longer life than the former. Conventional clad-type electrode plates are made by placing a lead alloy core in the center of a porous tube, and arranging a large number of tubes in parallel with the void filled with active material. Glass fiber is mainly used as the tube material.

Incidentally, in recent years, attempts have been made to seal storage batteries, and various improvements have been made. That is, when a discharged lead-acid battery is charged, it is charged while emitting oxygen gas from the anode plate. At first, not much gas is emitted, but as the active substance finishes charging, the amount of gas suddenly increases, and after that,
Most of the charged electricity goes into electrolysis of water. The more you charge the battery, the more water it decomposes, and 0.34 grams of water is lost per hour. In this way, charging does not reduce the amount of sulfuric acid, but it does reduce the amount of water, so water needs to be replenished. However, when there are many batteries in a set, supplying water while checking the condition of each battery is a difficult task. This led to the development of sealed batteries that do not require rehydration at all.

Conventionally, sealed batteries are 0.5 in paste type batteries.
It has been rapidly put into practical use by using a separator mainly made of ultrafine glass fibers with a diameter of ~2 μm. However, in paste-type batteries, it is necessary to narrow the gap between the electrode plates in order to facilitate the recombination of oxygen for sealing, which results in a shortage of electrolyte and poor utilization of active materials. With drawbacks.

On the other hand, a block body having a triangular prism-shaped space as shown in Fig. 2(d) has recently been proposed as an effective separator for clad-type sealed batteries (Special Publication WO8
5105227). In a block body having such a shape, the lead core metal and active material of the clad electrode are enclosed in a triangular prism-shaped space to constitute an anode plate, and has the following advantages.

■ Since the triangular prism-shaped space has a larger surface area for the same cross-sectional area than the cylindrical space, the utilization of the active material increases accordingly.

■ A large surface area also results in more efficient use of the electrolyte.

■ As mentioned above, in paste-type sealed storage batteries, the spacing between the electrode plates is designed to be as narrow as possible to facilitate recombination, and the separator is therefore thin, so the electrolyte is In contrast, in triangular prism-like lattice blocks, the utilization of active material is poor due to the lack of active material.
Since the lattice blocks the inside of the active material, the electrolyte is contained in the lattice block, and the electrolyte exists within the active material, so that it acts effectively at any depth of discharge.

- Furthermore, since the triangular prism-shaped anode plate is placed close to the cathode plate, the performance of oxygen and hydrogen recombination is very good, and charging can be performed quickly.

■ Prevents active material from falling off.

For this reason, an extremely high-performance clad-type sealed battery can be obtained by using a triangular prism-like lattice block separator as shown in FIG. 2(d).

Conventionally, such triangular prism-like lattice block separators have been manufactured by the following method (1) or (2).

■ Using a mold with a predetermined shape, a slurry of separator material is introduced and molded in one piece.

■ As shown in Figure 3 (a) and (b), two flat plates 30.3
In step 1, the contacts 33 are bonded by sandwiching the corrugated plate 32 obtained by bending or V-cutting.

[Problems to be Solved by the Invention] Among the above-mentioned conventional manufacturing methods, method (2) has a problem in that the manufacturing process is complicated and has many technical difficulties, resulting in extremely high manufacturing costs.

On the other hand, although manufacturing can be carried out relatively easily using the method (2), there is a problem in that it is difficult to firmly bond the flat plate 30, 31 and the corrugated plate 32 because the area of the contact point 33 is small. The active material enclosed in the separator expands and contracts each time it is discharged or charged, so if the adhesive strength of the separator is weak, it will not be able to withstand the internal pressure caused by the expansion and contraction of the active material, making it unsuitable as a structure that supports internal pressure. isn't it.

[Means for Solving the Problems] The present invention solves the above-mentioned conventional problems and provides a method for efficiently manufacturing a storage battery separator useful as a separator for clad-type sealed batteries at low cost. The method is to form grooves extending in the longitudinal direction of the paper product by pressing it with a roller or a rod on a flat paper product made of a material mainly made of glass fiber, and to form a paper product with the grooves formed therein. The gist of the present invention is a method for producing a separator for a storage battery, which comprises a step of overlapping and bonding the sheets together or the paper sheet and a flat sheet sheet.

[Action] By pressing a plate-shaped paper product made of a material mainly made of glass fiber with a roller or a rod-shaped body, grooves extending in the longitudinal direction of the paper product are formed. Since the paper product and the plate-like paper product are overlapped and bonded, it is possible to manufacture the product very efficiently in continuity with the papermaking line, and the bonding strength is also high because the contact area for bonding is sufficient.

Therefore, it is possible to extremely easily manufacture a lattice block made of a material mainly composed of glass fiber, which is useful as a separator for a clad-type sealed battery.

[Example] The present invention will be explained in detail below with reference to the drawings.

FIGS. 1(a) to 1(d) are cross-sectional views illustrating an embodiment of the method for manufacturing a separator for a storage battery according to the present invention.

In the method of this embodiment, first, a flat sheet-shaped paper body 1 made of a material mainly composed of glass fibers, as shown in FIG.

The papermaking body 1 is manufactured by a normal wet papermaking method. Although its thickness varies depending on the storage battery used in the separator to be manufactured, it is preferably 5 mm or more.

The paper product obtained by wet papermaking is pressed with a roller 2 as shown in FIG. 1(b) to form a recess with a predetermined cross-sectional shape extending in the longitudinal direction of the paper product 1 after draining and before heating and drying. Forming row 3.

The paper product 4.4' with grooves 3 formed in this way is semi-dried to the extent necessary to maintain its shape, and an adhesive is applied to the contacting surface, and then as shown in FIG. 1(C), After stacking them so that the grooves 3 and 3' face each other, they are heated and dried again while being pressed to be bonded.

In the present invention, the adhesive strength can be further increased by using an appropriate inorganic adhesive such as a water glass adhesive such as S i 1 pap 700 (Central Glass ■, trade name).

By adhering the paper products 4.4', a lattice block 6 having a space 5 with a circular cross section is obtained, as shown in FIG. 1(d).

By cutting this block 6 into a predetermined length as necessary, it can be made into a storage battery separator 10 as shown in FIG. 2(a).

In such a method of the present invention, by changing the shape of the roller used, separators for storage batteries having spaces with various cross-sectional shapes can be manufactured.

For example, a roller 1 with a rectangular cross section as shown in FIG.
2 to form a grooved strip 13 having a rectangular cross section.
By stacking and bonding the four pieces together, it is possible to obtain a separator 10 in the form of a lattice block having a square cross-sectional space as shown in FIG. 2(b).

In addition, a roller 1 having a hexagonal cross section as shown in FIG.
2, by stacking and bonding the paper structures on which grooves 13 with a pentagonal cross section are formed, a separator 10 in the form of a lattice block having spaces with a hexagonal cross section as shown in FIG. 2(C) is obtained. be able to.

Further, according to the present invention, a separator 10 of a lattice block having a triangular cross-sectional space as shown in FIG.
The method shown in FIGS. 5(a) to 5(d) is advantageous for manufacturing.

That is, first, as shown in FIG. 5(a), a concave strip 2 having a triangular cross section is formed on a papermaking body 23 by a roller 21 for forming the apex angle of the triangle and a roller 22 for forming the bottom part of the triangle.
4 and a grooved strip 25 having a rectangular cross section is formed, and then as shown in FIG.
As shown in b), pass the mold correction member 26 through the groove 25,
The shape of the grooved line 25 is modified to form a grooved line 27 having a trapezoidal cross section.

That is, the mold correction member 26 is shown in FIG. 6(a) (perspective view),
(b) (top view), (C) (left side view of Fig. 6 (a))
, (d) (right side view), the lower end part has a shape that spreads in the opposite direction to the traveling direction A, and this mold correction member 26 is attached to the grooved strip 25 having a rectangular cross section. arrow A
By passing in the direction shown in FIG. 5, the grooved line 25 is corrected according to the spread shape of the mold correction member 26, and the grooved line 27 is modified to have the shape as shown in FIG. 5(b).

Separately from the papermaking body 28 obtained in this way, a papermaking body 28' having concave stripes of the same shape as this was produced in the same manner, and the papermaking body 28.28' was shown in ': fS5 (C). By overlapping them as shown, heating and drying and adhering them, a lattice block 20 having a space 29 having a triangular cross section is obtained as shown in FIG. 5(d).

This block 20 can be cut into a predetermined length as necessary to form a separator 10 as shown in FIG. 2(d).

In the above description, the method of forming the grooves by pressing with a roller has been described, but in the present invention, the grooves can also be formed by pressing a rod-shaped body against the papermaking body.

Furthermore, the method of the present invention is not necessarily limited to bonding together paper products on which grooves are formed, but may also be applied to bonding a paper product 35 on which grooves are formed and a flat paper product 36, as shown in FIG. It's okay.

In addition, the manufacturing method of the present invention allows for continuous and efficient production by providing a pressing process using rollers or rod-shaped bodies on the production line of the papermaking process, and further providing a process of bonding them by heating and drying. It is possible to do so.

In the present invention, materials suitable for constructing the paper product will be described next.

In the present invention, the glass fibers constituting the paper product are mainly composed of small diameter glass fibers with an average diameter of 0.5 to 2 μm, and 0 to 20% by weight of large diameter glass fibers with an average diameter of 10 to 30 μm.
It is also preferable that it contains 0 to 30% by weight of glass fibers having an average diameter of more than 2 μm and less than 5 μm.

Glass fibers of medium and large diameters are cheaper than those of small diameters, and especially large diameter glass woven ILs have the advantage that the tensile strength of the separator can be improved by using them together.

The preferred average diameter of the small diameter glass fibers is 0.5 to 1.0.
It is more preferably 0.6 to 0.9 μm than 1 μm. If the diameter exceeds 1.0 μm, the pore size of the separator becomes large, and conversely, if the diameter is smaller than 0.5 μm, the manufacturing cost becomes high.

A preferable content of this small-diameter glass fiber is 60% by weight or more, particularly preferably 65% by weight or more based on the weight of the glass fiber. This is because if the content is less than 60% by weight, liquid absorption and liquid retention properties tend to be insufficient.

Further, the average length of this small diameter glass fiber is preferably 7 to 7.
50 mm, more preferably 10 to 40 mm. If the average length is shorter than 10 mm, the strength of the separator will be reduced, and if it is longer than 50 mm, it will be difficult to uniformly disperse the separator in water during papermaking.

Such small-diameter glass fibers can be manufactured by the FA method (flame method), centrifugation method, or other short glass fiber manufacturing methods.

In addition, in the present invention, the average diameter of the glass fibers is 3
Photographs were taken using an electron microscope of these locations, and the diameters of each of the 20 large fibers were measured at 0. Measured in 1 μm units,
It is calculated by taking the average value of these values.

When medium-sized glass fibers are used, the preferred average diameter is 2.0 to 5.0 μm, especially 3.0 to 4.0 μm.
It is. In addition, the content is 5.0 to 30 of the glass fiber weight.
．． It is preferably 0% by weight, especially 10.0 to 25.0% by weight.

By blending glass fibers with medium and small diameters, the amount of small-diameter glass fibers can be reduced, which is advantageous in terms of cost.

The length of this medium-thin diameter glass fiber is preferably 7 to 50 mm, particularly preferably 10 to 40 mm.

If large-diameter glass fibers are used, their preferred average diameter is 10-20 μm, especially 12-19 μm. In addition, the content is 8 to 20% by weight of glass 1Allfa.
, especially preferably 10 to 20% by weight. If the average diameter is smaller than 10 μm or the content is less than 8% by weight, the tensile strength improvement effect will be small,
If the average diameter increases by 20μmftn, or the content increases by 2
If the weight exceeds 0 weight, the liquid absorption and liquid retention properties of the separator will decrease. The length of this large diameter glass fiber is preferably 5 to 80 mm, particularly 6 to 40 mm.

A suitable range of the composition of the glass fiber will be explained below.

In the present invention, the glass that constitutes the separator! ! Although there is no particular restriction on the composition of the a-fibers, it is preferable to use alkali-containing silicate glass fibers. That is, when alkali-containing silicate glass fibers are used, a water glass-like substance is generated on the surface of the glass fiber during the papermaking process of the manufacturing process, and the adhesiveness of this generated water glass-like substance allows the fibers to be bonded together better. , the adhesive strength is further improved. In the present invention, among the alkali-containing silicate glass fibers,
Since it is used in storage batteries, those with good acid resistance are preferably used. This degree of acid resistance is based on an average fiber diameter of 1 m.
It is desirable that the weight loss when measured in accordance with JISC-2202 is 2% or less in the state of glass fibers of μ or less. In addition, the composition of such glass fibers is 60 to 75% SiO2 and 8 to 20% R20 (N) by weight.
It mainly contains alkali metal oxides such as a2o, 20, etc., but SiO2+ R20 is 75 to 90%.
), in addition, for example, CaOlMgO, B203, A1
203, ZnO.

Examples include those containing one or more of Fe2O3 and the like. An example of a preferable alkali-containing silicate glass is shown in Table 1 below.

Table 1 In the present invention, in addition to such alkali-containing silicate-based glass fibers, synthetic fibers such as water-absorbing synthetic fibers may be contained.

In that case, water absorbent synthesis! As the a-fiber, it is preferable to use acrylic fiber or the like whose surface has been treated with high water supply, and specifically, Lanseal-F (manufactured by Nippon Exlan Kogyo ■, trade name) is preferable.
etc. Lanseal-F is a highly water-absorbing organic material with a diameter of approximately 15 μm that holds 20 to 30% of the total weight of polyacrylic acid on the surface of acrylonitrile fibers! It is a fiber.

In the present invention, when synthetic fibers are used in combination, the blending ratio is 801% or more of glass fibers and synthetic fibers! a fiber 2
The content shall be 0% by weight or less. Synthesis 1a f (I content is 20
When the amount is more than 1% by weight, sufficient liquid absorption and swelling power cannot be obtained, resulting in insufficient liquid retention. By blending synthetic fibers, strength and rigidity can be improved, and good workability can be obtained in the battery assembly process.

Furthermore, if necessary, by adding a liquid binder such as a water glass adhesive, it is possible to improve the strength of the separator through adhesion.

In this case, as the water glass adhesive, in addition to water glass,
Inorganic adhesives containing water glass, specifically rSi 1pa
p700''. The amount of water glass adhesive added varies depending on the composition, average diameter, average length, etc. of the glass fibers, but if it is too large, the adhesion will be too strong, inhibiting swelling during liquid absorption, and resulting in poor liquid absorption. Therefore, it is preferable that the content of -M in the separator is 0 to 15% by weight in terms of solid content.

In order to manufacture such a paper body made of a material mainly composed of glass IA F:L, it can be manufactured by a paper making method similar to that used in a normal separator manufacturing method. That is, when using alkali-containing silicate glass fibers as glass fibers, the glass fibers and, if necessary, synthetic FA fibers are mixed at a pH of 2.5 to 3.5 (in the case of only glass IA FA, pH is less than 3). ) for a certain period of time, e.g. 5 to 20 minutes, using a water jet disperser etc., the fibers are dispersed without cutting them as much as possible, and then wet-formed to coat the surface of the glass fibers. An adhesive layer, perhaps a water glass layer, is formed and then heated to a predetermined temperature, e.g. 80-180°C.
The glass Ta fibers can be obtained by adhering them to each other by the water glass on their surfaces by heating to .

Note that it is also possible to add water glass or a liquid binder as described above during the dispersion of the fibers in water or the papermaking process to promote adhesive action.

In addition, a dispersant may be used for dispersion. or,
By spraying dialkyl sulfosuccinate onto a wet-paper-formed fiber paper product, for example, a fiber paper product on a paper-making conveyor, the dialkyl sulfosuccinate is attached to the glass fibers in an amount of 0.005 to 10% by weight. The hydrophilicity of the separator can improve the liquid retention properties of the separator. The dialkyl sulfosuccinate may be mixed into the dispersion water in the papermaking tank as described above (instead of being sprayed).

Normally, the glass fiber paper product wet-formed in this way is dried along a drum dryer and made into a product, but in producing the separator of the present invention, before drying the obtained paper product, As described above, the grooves are formed by pressing the roller or the rod-shaped body.

[Effects of the Invention] As detailed above, the method for manufacturing a storage battery separator of the present invention can be applied to glass! A grooved strip extending in the longitudinal direction of the paper-shaped article is formed by pressing a flat sheet-shaped article made of a material mainly composed of A-fibers with a roller or a rod-shaped body, and the sheet-shaped articles with the grooves formed thereon or the paper article are The present invention includes a step of overlapping and joining a body and a flat sheet-formed body, and it is possible to extremely efficiently manufacture a lattice block-shaped separator useful as a separator for a clad-type sealed battery.

Therefore, the manufactured separator has a high electrolyte retention property,
In addition to having the features of a lattice block separator, which has excellent liquid absorption properties, good active material retention performance, high utilization of electrolyte and active material, and can be sealed, It has strong adhesive strength that can sufficiently withstand internal pressure applied to the separator, and is extremely useful as a separator for high-performance clad-type sealed batteries.

[Brief explanation of drawings]

FIGS. 1(a) to (d) are cross-sectional views illustrating an example of the method for manufacturing a storage battery separator of the present invention, and FIGS. 2(a) to (d)
) is a perspective view showing a specific example of a storage battery separator manufactured by the method of the present invention, FIGS. 3(a) and (b) are sectional views explaining the conventional manufacturing method, and FIGS. 4(a) and ( b) is a cross-sectional view showing another example of the groove formed with the roller; FIGS. 5(a)-
(d) is a sectional view showing another example of the method of the present invention. FIGS. 6(a) to 6(d) are views showing the mold correction member, where (a) is a perspective view, (b) is a plan view, and (C) is a
A) is a left side view, and (d) is a right side view of the same. FIG. 7 is a sectional view showing a different example of the method of the present invention. DESCRIPTION OF SYMBOLS 1... Paperwork, 2.12.21.22... Roller, 3.13.24.25.27... Concave strip, 26... Mold correction member. Agent Patent Attorney Tsuyoshi Shigeno Figure 1 Figure 2 (a) B:==Nie=:=====:K~-31 Figure 4 (a) (b) Figure 5 (C) ( d)

Claims (7)

[Claims] (1) Forming grooves extending in the longitudinal direction of the paper body by pressing a flat sheet body made of a material mainly made of glass fiber with a roller or a rod-like body, A method for producing a separator for a storage battery, comprising the step of overlapping and joining the paper product and a flat paper product. (2) Materials mainly made of glass fiber have an average diameter of 0.5~
The manufacturing method according to claim 1, wherein the material is mainly composed of 2 μm glass fiber. (3) Materials mainly made of glass fiber have an average diameter of 0.5~
Mainly composed of glass fibers with a diameter of 2 μm, 0 to 30% by weight of glass fibers with an average diameter of more than 2 μm and less than 5 μm, and an average diameter of 5 to 5 μm.
30μm glass fiber 0-20% by weight, synthetic fiber 0-2
The manufacturing method according to claim 2, wherein the material contains 0% by weight and 0 to 15% by weight of liquid binder. (4) The thickness of the plate-shaped paper product forming the grooves is 5 mm or more. Any one of claims 1 to 3.
The manufacturing method described in section. (5) The manufacturing method according to any one of claims 1 to 4, in which the paper products on which grooves are formed are stacked on top of each other so that the grooves are aligned. (6) The manufacturing method according to any one of claims 1 to 5, wherein the joined paper products are cut in a direction crossing the longitudinal direction. (7) A claim that includes a step of correcting the cross-sectional shape of the groove into a dovetail shape by passing a mold correction member in the longitudinal direction of the groove formed by pressing with a roller or a rod-shaped body. The manufacturing method according to any one of Items 1 to 6.