JP3345458B2 - Flexible positive electrode mixture film for dry battery and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible positive electrode mixture film for a dry battery and a method for producing the same, and more particularly, to a paper-like flexible film (flexible) having a wide thickness range. The present invention relates to a possible positive electrode mixture film and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION A water-based resin is generally used as a binder for producing a positive electrode mixture film. Therefore, water is used as the solvent. A stainless steel net is generally used as the support. After providing the positive electrode mixture layer on the stainless steel net,
It is necessary to dry out the water sufficiently. There is a disadvantage that a large amount of energy is required for drying and removing the water. In addition, since the above-mentioned aqueous resin binder has a drawback of lacking flexibility, when a positive electrode mixture film having a thickness of 0.4 mm or more is to be manufactured, the drying time becomes longer. There is also a disadvantage that a crack is generated by the shrinkage of the film, and a continuous thick film cannot be produced.

On the other hand, a film having a thickness of 0.1 mm or less cannot use a stainless steel net as a support, and thus lacks strength and is not practical.

That is, since the conventional positive electrode mixture film lacks flexibility as described above, it requires a stainless steel net as a support. Without this stainless steel net, it is easily broken by bending. There were also disadvantages.

[0005]

SUMMARY OF THE INVENTION In view of the above points, the present invention provides a positive electrode mixture film for a dry battery, which does not consume much energy and time in a drying step, and has sufficient flexibility, and a method for producing the same. The purpose is to do so.

The positive electrode mixture film for a dry battery according to the present invention comprises manganese dioxide and carbon as main components on a nonwoven fabric, paper, woven fabric or heat-resistant film, and a rubber or elastomer as a binder for the powder. A positive electrode mixture containing 3 to 10% by weight of a conductive polymer material.

[0007] The manufacturing method of the soluble橈性cathode mixture film according to the present invention, manganese dioxide, the amount of solution such as carbon and high content <br/> child material content is 3-10 wt% Mixed, non-woven, paper, woven or heat-resistant as support
The film is coated, dried and rolled on a film to form a film.

According to the positive electrode mixture film of the present invention,
As a binder, 3 to 10% by weight of a flexible polymer material ( go)
(Elastomer, elastomer ) can be used to make a flexible film, and by using a non-woven fabric as the support, it is more flexible, less expensive, and thicker than when stainless steel is used. There is an advantage that there is a degree of freedom.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The above-mentioned flexible positive electrode mixture film is made of a flexible polymer material ( rubber, elastomer, etc.) as described above.
- ) Is contained in an amount of 3 to 10% by weight. This polymer material
It is a binder for manganese dioxide and carbon powder, and has heat resistance because it is subjected to a drying process, and it needs to be formed into a film. Preferably, it is a material. As this material, a non-polar material having a small polarity is preferable in consideration of the battery material. For example, in the case of a rubber material, isoprene rubber (IR),
R), styrene-butadiene rubber (SBR), ethylene-propylene rubber (EPR, EPDM), butyl rubber (IIR), and the like. For elastomers, olefin-based elastomer, SIS, SBS, etc., can be mentioned. .

The addition amount of such a material is 3 to 10% by weight.
However, if the addition amount is less than 3% by weight, the flexibility is insufficient and film formation is difficult, and if it exceeds 10% by weight, the conductivity of the positive electrode mixture film is insufficient and the film is good. No effective discharge effect can be obtained.

The above-described positive electrode mixture is formed on a support. As the support, for example, non-woven fabric, Japanese paper
Any paper, woven cloth (eg nylon cloth, tetron cloth)
Or various heat-resistant films (for example, cellophane, polyester film, polyimide film, etc.) can be mentioned.

The thickness of the support is preferably 0.05
It is good to be 1.0 mm. If the thickness is less than 0.05 mm, the strength may be insufficient. On the other hand, if the thickness exceeds 1.0 mm, the flexibility becomes small and the thickness becomes too large.

Next, a method for producing a flexible positive electrode mixture film according to the present invention will be described.

According to the production method of the present invention, 3 to 10% by weight of a polymer material dissolved in a solvent is added to manganese dioxide and carbon powder, coated on a support such as a nonwoven fabric, and dried. .

As the above-mentioned solvent, those which can dissolve the polymer and evaporate well are preferable. For example, toluene, methyl ethyl ketone, acetone, ethyl acetate, esters and the like can be used.

The concentration of the polymer solution is 5 to 20% by weight.
Is preferred. When the amount is less than 5% by weight, the viscosity is too low to coat easily, and there is a possibility that a large amount of time and energy is consumed for drying.
Mixing with manganese dioxide and carbon powder becomes difficult, and coating becomes difficult due to high viscosity.

[0017]

EXAMPLES Examples and comparative examples were manufactured according to the following composition and specifications to prepare samples. As for the comparative example, a stainless steel mesh was coated and dried using an aqueous binder. In the examples, a rubber-based binder (styrene-butadiene rubber) was used, and a 0.1-mm-thick polyester-based nonwoven fabric was coated and dried. The resulting positive electrode mixture film was overlapped with a zinc plate as a negative electrode via a separator, a zinc chloride aqueous solution was poured as an electrolytic solution, and the generated voltage was examined. Further, in order to examine the flexibility of this battery, a vent of about ± 10 mm was added and the state was observed.

[0018]

[0019]

[0020]

As described above, according to the flexible positive electrode mixture film of the present invention, a flexible support such as a nonwoven fabric is prepared by adding manganese dioxide to a flexible polymer material. Since it is provided on the upper side, a flexible positive electrode mixture film can be formed. For this reason, there is an advantage that it is possible to provide a positive electrode mixture that is thinner and harder to break than conventional ones.

According to the method for producing a flexible positive electrode mixture film of the present invention, there is an advantage that the above-mentioned flexible positive electrode mixture film can be easily produced.

Claims (2)

(57) [Claims] 1. A non-woven fabric, paper, woven fabric or
On a heat-resistant film , manganese dioxide and carbon are the main components, and rubber or elastomer is used as a binder for the powder.
A flexible positive electrode mixture film for a dry battery, comprising a positive electrode mixture containing 3 to 10% by weight of a flexible polymer material as a tomer. 2. Manganese dioxide, carbon and rubber.
Rubber or elastomer in an amount such that the flexible polymer material is 3 to 10% by weight.
A method for producing a flexible positive electrode mixture film for a dry battery, comprising mixing a radial polymer material solution, coating, drying and rolling on a nonwoven fabric or a material similar thereto as a support to form a film.