JPS5852301B2 - Separator for storage batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a separator for storage batteries, particularly a separator for sealed lead-acid batteries mainly made of glass fiber.
To provide a separator for a storage battery at a low cost, which has an appropriate electrolyte absorption degree, has a strong holding power, has a small pore diameter, has extremely strong mechanical strength, has excellent restorability, and is easy to handle. Oh, that's what I'm aiming for.

Conventionally, as a storage battery separator mainly made of glass fiber, there is a glass mat, for example, which has a fiber diameter of 1
Glass fibers of 5 to 25μ are randomly interlaced using a wet or dry method, and the fibers are bonded together with a binder such as gelatin, starch, or acrylic acid emulsion, and the absorption and retention power of the electrolyte is It has the disadvantage of being extremely small and having large pore diameters.

On the other hand, this type of separator mainly made of glass fibers having a small fiber diameter has also been proposed.

For example, Japanese Patent Publication No. 48-32854 discloses that a fine glass cotton felt material made by forming a bottom of a plate-like felt material made of glass cotton made of short fibers with a fiber diameter of 1 to 4 μm is used as a separator for storage batteries. However, this has the disadvantage that the pore size is large and the mechanical strength is low, making it difficult to handle during battery assembly.

Also, in Japanese Patent Publication No. 47-40733, the fiber diameter is 4 to 1.
For storage batteries, a microporous layer of fibers is formed on a glass mat by dispersing short pieces of 0 μ glass fiber and short pieces of mineral fiber much thinner in water in appropriate proportions and letting the mixture flow down onto the glass mat. Separators have been proposed.

However, in this type of product, the glass mat serving as a support and the microporous layer thereon peel off and separate into two layers.

The mineral fiber is 5 to 25w as described in this publication.
Some t% ratio -Vc have the disadvantage that the pore size is too large and the electrolyte retention and absorption are insufficient.

In addition, in Japanese Patent Application Laid-open No. 47-4222, the fiber diameter is 0.
．． Glass fibers with non-woven short fibers of 1 to 10 μm have been proposed, but these have the disadvantage that they are extremely difficult to handle during battery assembly.

Furthermore, Japanese Patent Publication No. 42-24467, Japanese Patent Publication No. 43-33
45, Japanese Patent Publication No. 44-18607, etc., a glass mat made of glass fibers with a fiber diameter of 10 to several microns is treated with a phenol resin liquid or a synthetic resin liquid to the extent that the pores are not destroyed. has also been proposed.

However, all of these have a small amount of electrolyte retained,
However, it also has the disadvantage of insufficient holding power.

The inventors of the present invention have repeatedly conducted research to overcome these drawbacks, and have already published Japanese Patent Application Laid-Open No. 51-99236 and Japanese Patent Application Laid-open No. 51-10.
The results were published in publications such as Publication No. 1837.

In other words, the separator for storage batteries disclosed in JP-A No. 51-99236 is mainly composed of glass fibers with an average fiber diameter of 1μ or less, in which glass fibers with an average fiber diameter of more than 1μ are mixed. In the separator, glass fibers with an average fiber diameter of 5μ or more are mixed randomly at a ratio of 1 to 20 wt%, and the tensile strength is 1.5 to 2.5 kg/ca, which is higher than that of the previous one. 0.5
This makes it possible to increase the distance compared to km4.

In addition, 1 to 20 wt% of glass fibers with a fiber diameter of 5μ or more
Compared to conventional products with a ratio of 1 and 1, it can be manufactured at a considerably lower cost.

The separator for a storage battery disclosed in Japanese Patent Application Laid-open No. 51-101837 is characterized by being composed of glass fibers and synthetic fibers with an average fiber diameter of 0.5 to 5.0 μm. Although its mechanical strength is improved by the reinforcing effect of the synthetic fibers, it has the disadvantage of being expensive because the pores are large and only thin glass fibers with a fiber diameter of 5.0 μm or less are used.

The present invention relates to a storage battery separator that has been further improved based on these already published technical findings, and has good electrolyte absorption and high electrolyte retention required for a sealed lead acid battery separator. It is possible to provide a separator for a storage battery that satisfies all aspects of basic characteristics, such as having small pore diameters, extremely high mechanical strength, and being inexpensive.

Some embodiments of the present invention will be described below.

Example 1 Glass fiber 1 with a fiber diameter of 0.5μ as shown in FIG.
50wt%, 10w of glass fiber 2 with a fiber diameter of 6μ
t%, fiber diameter 11μ glass fiber 3 at a ratio of 40wt% as a binder between two fibers, iodine titer □70 (7) A~-
? tt+17 immersion L"C, the ratio of 5 parts by weight of glass fibers to which oil was attached and 95 parts by weight of glass fibers to which no interfiber binder was attached at the same ratio of glass fibers was mixed with 100 parts by weight of water. 0.5 parts by weight.

Paper was made using a normal paper machine and dehydrated and dried to make a separator for storage batteries.

Note that 4 and 5.6 have fiber diameters of 0.5μ, 6μ, and
It is a glass fiber to which no interfiber binder of 11μ is attached.

Example 2 60 wt% of glass fibers with a fiber diameter of 0.5 μm, 36 wt% of glass fibers with a fiber diameter of 15 μm, and 4 wt% of glass fibers with a fiber diameter of 11 μm to which cottonseed oil had been attached to the surface in advance were subjected to the same operation as in Example 1. It was made into a separator for storage batteries.

The characteristics of Examples 1 and 2 will be shown below in comparison with the conventional one.

Note 1) Liquid content: 1.30 After immersing the test piece in dn2so4, pull it up and hold it in a suspended state for 5 minutes.
The value obtained by dividing the amount of 2SO4 by the volume in its dry state.

2) Amount of liquid retained: After a test piece is immersed in 1.30 dH2SO, pulled up, and held under 6G acceleration for 30 seconds, the ratio of the amount of remaining H2SO4 to the initially absorbed amount is expressed in excellent.

3) Resilience: Measure the thickness T of the test piece under a load of 5 times and 4 times, and apply a load of 20 ky/dd to the same location for 1 minute.

Next, remove the load and go back to 5kfd! Thickness T2 is measured under load, and T2 is divided by T, and the value is expressed as the ratio.

Example 3 A separator for a storage battery was obtained in the same manner as in Example 1, except that the diameter of the glass fibers and the amount of glass fibers to be attached in advance were changed using soybean oil as an interfiber binder.

Table 2 shows its initial characteristics. Example 4 A separator for a storage battery was obtained using glass fibers containing zinc white (Zno) and having the same mixing ratio as in Example 1.

Table 3 shows this special order.

*As is clear from the above examples, the storage battery separator of the present invention has sufficient electrolyte absorption for use in sealed lead-acid batteries, and its holding power is low, and the pore size is small and mechanically strong. It is extremely easy to handle, has excellent restoration properties, and is extremely easy to handle.

The distinguishing features of the separator for storage batteries of the present invention compared to those previously announced by the present invention and others are its smaller pore diameter, mechanical strength, and greater restorability.

JP-A-51-99236 and JP-A-51-101
Table 4 shows a comparison of the typical characteristics of the device shown in Japanese Patent No. 87 and the device according to an embodiment of the present invention.

That is, the liquid content, which is the absorption of electrolyte, of the separator for a storage battery of the present invention is smaller than that previously announced.

This is because glass fibers with different fiber diameters are combined and intertwined with organic fibrous materials to further improve strength.However, this level of decrease in electrolyte absorption is due to the oxygen cycle paced sealing. It turned out that it was not a problem for type lead-acid batteries.

This is because when displaying the liquid content in the table in Section 1, the volume of the separator in a dry state is divided as the denominator, but in actual batteries, both sides of the separator are held down by electrode plates. This seems to be due to the fact that it cannot expand in the thickness direction.

The liquid retention capacity of the separator for storage batteries of the present invention is greater than that previously announced, but this is because the separator is dense as described above, and is suitable for sealed lead-acid batteries.

Furthermore, although it is preferable that the pore diameter of the separator be small, the maximum pore diameter of the separator of the present invention is approximately 1/2 of that of the separator previously announced.

This is mainly composed of glass fibers with a fiber diameter of 1μ or less, which are intricately intertwined with glass fibers with a fiber diameter of more than 1μ, and these fibers are bonded by glass fibers to which an interfiber binder has been attached in advance. This is because the gaps between the intertwined fibers are made extremely small.

As shown in Table 4, the tensile strength of the separator for storage batteries of the present invention is about 2 to 20 times greater than that previously announced.

Although it is desirable for a separator to have a high mechanical strength in manufacturing a storage battery, handling of the separator for a storage battery of the present invention is extremely easy because the separator has a moderate tensile strength.

This consists mainly of glass fibers with a fiber diameter of 1μ or less, which are intricately intertwined with glass fibers with a fiber diameter larger than 1μ, and among the glass fibers thicker than 1μ, there are fibers with a diameter of 10 to 30μ. This is because glass fibers of various diameters are bonded together by glass fibers that have been treated with an interfiber bonding agent and have an interfiber bonding ability.

As shown in Table 4, the recovery properties of the storage battery separator according to the present invention are greater than those previously announced.

A storage battery is usually made by stacking negative and positive polar plates alternately with a separator in between, and at this time, taking into consideration the lifespan of the storage battery, the two polar plates are stacked together under a certain pressure.

In this case, if the separator does not have restorability, the electrode plates in the completed storage battery will be in an unstressed state, which is not preferable.

In this respect, the storage battery separator of the present invention has good restorability and is therefore suitable for storage batteries.

This is because the storage battery separator of the present invention contains glass fibers with a diameter of 10 to 30μ among the glass fibers thicker than 1μ, and the higher the proportion of these fibers, the better the restorability. However, this has a fiber diameter of 10
This is thought to be due to the fact that the thick glass fibers of ~30μ act like a spring in the separator.

Therefore, when glass fibers having a fiber diameter of 10 to 30 μm are mixed in the separator, the restorability is greatly improved.

As described above, the separator for storage batteries of the present invention has an appropriate electrolyte absorption degree, has a strong holding power, has a small pore size, has extremely high mechanical strength, has excellent restorability, is easy to handle, and has a 10 to 30 μm capacity. It is extremely inexpensive because it contains a large amount of glass fibers with a fiber diameter of .

This is because the separator for storage batteries of the present invention is mainly composed of glass fibers with a fiber diameter of 1 μm or less, glass fibers with a fiber diameter of more than 1 μm, and glass fibers with an interfiber bonding agent attached to the surface to impart interfiber bonding ability. The fiber diameter is 10 to 30% in the glass fiber which is made of
This is due to the structure in which μ glass fibers are interlaced and bonded to each other.

The main body of the storage battery separator of the present invention must be glass fiber of 1 μm or less.

This means that if the main body is glass fiber that is thicker than 1μ, it will be microporous.
This is because the customization of the separator deteriorates in all aspects such as electrolyte absorption, liquid retention, and mechanical strength.

The ratio of glass fibers having a fiber diameter of 1 μm or less to the entire storage battery separator is preferably 50 to 95 wt%.

This means that the proportion of glass fibers with a fiber diameter of 1μ or less is 50W.
If it is less than 95 wt%, the price will go down, but properties such as microporosity, electrolyte absorption, liquid retention, and mechanical strength will be extremely poor.If it is more than 95 wt%, the price will increase and mechanical strength will decrease. Because it does.

Furthermore, the proportion of glass fibers with a fiber diameter larger than 1μ is 5 to 4.
5 w ttljlJK is nice.

This is because if the proportion of glass fibers with a fiber diameter larger than 1μ is greater than 45wt%, the price will decrease, but properties such as microporosity, electrolyte absorption, liquid retention, and mechanical strength will be extremely poor, and if the proportion is greater than 45wt%, The price increases with less mechanical strength,
This is because restorability also decreases.

The fiber diameter is 1 in glass fibers whose fiber diameter is thicker than 1μ.
The proportion of glass fibers having a diameter of 0 to 30μ is preferably 20 to 100 wt%.

This is because, if the proportion of glass fibers with a fiber diameter of 10 to 30 μm is less than 20 wt %, special features such as restorability and mechanical strength will deteriorate.

The proportion of glass fibers treated with interfiber binder is 0.1-4
Preferably, it is 0 wt%.

It is 0.1 wt% from the proportion of the treated glass fiber.
If the amount is less than 40 wt%, the mechanical strength of the separator cannot be improved at all, and if it is more than 40 wt%, the essential characteristics of a sealed lead-acid battery, such as electrolyte absorption and liquid retention, will be impaired.

Further, the glass fibers to which the interfiber binder is attached in advance to the surface may be glass fibers of any diameter constituting the separator of the present invention, whether the fiber diameter is 1 μm or less or thicker than 1 μm.

The interfiber binder used in the examples is vegetable oil, but in addition to animal fats and oils, normal interfiber binders such as starch, resin-based acrylic emulsion, and phenolic resin can also be used, or they can be masked with an oil film. It is also possible to use

However, in reality, the dispersibility of glass fibers in water is improved,
Among vegetable oils, semi-drying oils and drying oils are more suitable from the viewpoint of film-forming properties such as forming a film and exhibiting inter-fiber bonding strength simply by drying, inter-fiber bonding properties, and price.

Although the composition of glass fiber must be acid-resistant.

It is preferable that a zinc compound such as zinc white be included in the composition of the separator in order to improve the ease with which the fibers become entwined with each other and the mechanical strength.

Generally, in lead-acid batteries, impurities such as metals and metal compounds should be avoided as much as possible as they increase self-discharge and corrosion, but even if zinc compounds are included in glass fibers, they will not have a negative effect on sealed lead-acid batteries. There was found.

Although the storage battery separator of the present invention is manufactured using a wet method as an example, the present invention is not limited to this and can be achieved by any manufacturing method, wet or dry. It is clear that a separator for a storage battery having the same configuration as the invention can exhibit exactly the same effects.

Furthermore, if necessary, high-strength fiber cloth or yarn can be arranged in a desired direction to further improve the tensile strength.

Furthermore, when it is necessary to further limit the micropore diameter, it is of course possible to combine it with a conventional separator for storage batteries or with a conventional glass mat having a large fiber diameter.

As detailed above, the separator for storage batteries of the present invention has an appropriate electrolyte absorption degree, has excellent retention strength, has a small pore diameter, has extremely high mechanical strength, has excellent restorability, and is easy to handle. It is easy to use and is also extremely inexpensive compared to the one announced in Part 1, so it will greatly contribute to improving the performance of sealed lead-acid batteries.

[Brief explanation of the drawing]

FIG. 1 is an enlarged view showing one embodiment of the present invention.

Claims (1)

[Scope of Claims] 1 Mainly composed of glass fibers with a fiber diameter of 1μ or less, and glass fibers with a fiber diameter of more than 1μ are mixed, and some of the glass fibers with a fiber diameter of more than 1μ are fibers. A storage battery separator containing glass fibers with a diameter of 10 to 30μ is separated by a group of glass fibers to which an interfiber binder has been attached in advance and a group of glass fibers to which an interfiber binder has not been attached. A sheet-like separator for a storage battery, in which the glass fibers in both fiber groups are randomly arranged and intertwined, and the fibers are bonded to each other by the bonding agent that is previously attached. 2 Glass fiber with a fiber diameter of 1 μ or less is 50 to 95 w
t%, glass fiber with fiber diameter thicker than 1μ is 5~50w
t%, and among these glass fibers O0l~4
The separator for a storage battery according to claim 1, which is made of 0 wt % glass fibers with an interfiber binder attached in advance. 3. The separator for a storage battery according to claim 2, wherein glass fibers with a fiber diameter of 10 to 30 μm are present at a ratio of 20 wt % or more among the glass fibers with a fiber diameter of 1 μm or thicker. 4. The separator for a storage battery according to claim 1, wherein the interfiber binder is an oil or fat. 5 Claim 1 in which the glass fiber contains a zinc compound
A separator for storage batteries as described in .