JPS6276256A - Air electrode - Google Patents

Abstract

PURPOSE:To improve the polarization characteristic by employing such material as having macromolecular chain as metal phthalocyanine. CONSTITUTION:Polyethylene, poly chloride vinyl, poly chloride vinylidene, nylon 66, nylon 12, etc. are employed as metal phthalocyanine having macromolecular chain. The volume of metal phthalocyanine to be used is properly selected with correspondence to the using condition of air-electrode or whether it is used as collected powder having high porosity or previously molded into a rod or a plate and the type of material to be used together.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air electrode used in air cells, fuel cells, etc., and particularly relates to an air electrode containing metal phthalocyanine as at least one type of catalyst.

(Prior Art) The use of precious metals such as silver as a catalyst for oxygen reduction has disadvantages such as high cost. Therefore, it has been considered to use metal phthalocyanine as a catalyst. -For example, JP-A-5.8. Publication No. 53159: There is a disclosure of an air electrode using a metal phthalocyanine compound having a hydroxyl group or a radical having a hydroxyl group and a carboxyl group.

(Problem to be solved by the invention) The polarization characteristics are insufficient. That is, conventional air electrodes containing metal phthalocyanine cannot have good polarization characteristics because their catalytic activity is small from the beginning and further decreases over time.

(Means for solving the problem) A metal phthalocyanine having a polymer chain is used. That is, 1 the present invention provides at least one of the metal phthalocyanide/catalysts.
The gist of the present invention is to provide an air electrode characterized in that in the air electrode containing a species and a metal phthalocyanate, one having a high f) chain is used as the metal phthalocyanide/.

The details will be explained below.

Metal phthalocyanines with polymer chains include 1 polyethylene, polyvinyl chloride, polyhynylidene chloride, nylon 66, nylon 12° polymethyl acrylate, polyethyl methacrylate, polycarbonate, and copolymers of these! Examples include combinations with metal phthalocyanine such as iron phthalocyanine, nickel phthalonanine, cobalt phthalocyanine, chromium phthalocyanine, copper phthalocyanine, and manganese phthalocyanine. These may be formed by direct bonding, or may be connected by a linking hand, or the metal phthalocyanine moiety bonded to the polymer chain may have polymerizable properties such as dimers or trimers, or may be sulfonic acid derivatives. It may also be something that has undergone degeneration, such as becoming. It is also possible to have different types of central metals.

This metal phthalocyanine having a polymer chain can be obtained, for example, as follows. That is, 4. 4', 4
/, / 4/// An example of obtaining iron phthalocyanine tetracarboxylic acid and carbonyl chloride to obtain iron phthalocyanine having a polystyrene chain will be shown.

Trimellitic anhydride, anhydrous ferrous chloride, and urea were prepared in a molar ratio of 4: t, t, r: 5, and a mixture was prepared with an appropriate amount of ammonium molypdenoate (catalyst) and alkylated naphthalene, and 150 to 160' C1 hour, 190-20
The mixture was heated and stirred at 0°C for about 6 hours, filtered hot, and then washed with benzene or the like.

Vacuum dry this at about 50℃ to obtain a crude 4.4'4/
: 4 ///Iron phthalocyanine tetracarboxylic acid is obtained, further recrystallized using 8 times the amount of 98% sulfuric acid, washed with P vortex, and dried.

(11) About carbonyl chloride 4,
4z,, 41', 4//'Iron phthalocyanine・
Tetracarboxylic acid was added little by little to 6 times the amount of chlorosulfonic acid, heated and stirred at 140°C for about 1 hour, poured into ice water, immediately washed with r-vortex and ice water, dehydrated with acetone, and further vacuumed. dry.

(iii) For iron phthalocyanine/having polystyrene chains, 20 parts by weight of polystyrene (degree of polymerization 200) is dissolved in 20 times the amount of halogenated hydrocarbon (trichloroethane),
Catalyst aluminum chloride and 5MM parts 4.4, 4.4
After adding iron phthalocyanine-tetracarbonyl chloride and reacting at 900 G for about 3 hours, the halogenated hydrocarbon used as a solvent and the aluminum chloride as a catalyst are removed.

Here, examples having polystyrene chains are cited because they have good moldability and shaping properties such as film formation, and have water repellency.

Furthermore, the description of the iron phthalonanine system is merely an example. That is, it can be obtained in the same way even when nickel, cobalt, chromium, copper, etc. are used as the central metal. Furthermore, this example is based on the Friedel-Crafts reaction method. Other suitable methods may also be used.

7. According to the Li-Del-Crafts reaction method, products with a high degree of polymerization with chains can be easily obtained. In general, the higher the degree of polymerization with the chain, the better the polarization characteristics tend to be.

Other materials used with the metal phthalocyanine having a polymer chain mentioned above include those for improving conductivity such as graphite and acetylene black, and other catalyst materials such as activated carbon.

Examples include excipients such as fluorine-based resins. Of course, if metal phthalocyanine having a polymeric chain is also used as an excipient, other excipients may not be used, and known materials may be used as appropriate. However, the combined use of activated carbon is good. Not only can the catalytic ability of activated carbon be utilized.

It is also possible to use it as a carrier of metal phthalocyanine having a polymer chain.

Further, it may be selected as appropriate depending on the metal phthalocyanine form having a polymer chain and the type of other materials used in combination. By the way, when using activated carbon and acetylene black together as a powder aggregate, generally good results can be obtained if they are used in an amount of about 1% to 20% by weight (based on the total amount of the three). I can do it.

(Example) <Example 1> 50 parts by weight each of coconut shell activated carbon and acetylene black sieved to 300 mesh or less, and iron phthalocyanine having polystyrene chains sieved to 500 mesh or less (by the Friedel-Crafts reaction method described above). After uniformly mixing 5 parts by weight of the obtained product, it was impregnated with a polytetrafluoroethylene emulsion for water repellent treatment, taken out, washed, dried, and further pressed under a load of 1oo'7.

An air electrode with a thickness of 0.5 mm was obtained.

Comparative Example 1 The same procedure as in Example 1 was carried out except that iron phthalocyanine was used instead of iron phthalocyanine having a polystyrene chain.

<Example 2> After uniformly mixing the same coconut shell activated carbon/parts by weight as used in Example 1 with 10 parts by weight of polystyrene, it was mixed to a thickness of 0.
It was extruded into a 5ynm sheet and fired at 150°C to obtain an air electrode.

Comparative Example 2 The procedure was the same as in Example 2 except that iron phthalocyanine was used instead of iron phthalocyanine having a polystyrene chain.

Example 3 The same procedure as in Example 1 was carried out except that copper phthalocyanine having a polystyrene-polyethyl acrylate copolymer chain was used instead of iron phthalocyanine having a polystyrene chain.

Comparative Example 3 The same procedure as in Example 3 was carried out except that copper phthalocyanine was used instead of copper phthalocyanine having a chain of polystyrene-polyethyl acrylate copolymer.

(Effects of the Invention) Figure 1 shows the results of measuring the polarization characteristics for each side. In addition, when assembled into a button-type air battery, the discharge characteristics (
Figure 2 shows the results of examining the load resistance (100Ω). Sho 1
The assembled battery is an R44 type, with a 0.4
A cellulose-based air permeable membrane, a polytetrafluoroethylene water-repellent membrane, a current collector made of a nickel mesh, cellulose on each side are placed inside a nickel-plated stainless steel cathode case with two air holes of m diameter. A system separator and a cellulose-based absorbent paper are laminated in order, and a gelled caustic potash solution containing dispersed frozen zinc powder is used as an electrolytic solution.
The layer-clad cathode case was separated from the cathode case using nylon 12 as a gasket.

First, as shown in FIG. 1, the polarization characteristics obtained in Examples are better than those obtained in Comparative Examples. This is because the catalytic activity is working well at least immediately after use. Further, as shown in FIG. 2, the products obtained in the examples have better stability over time, and FIG. 1 shows the polarization characteristics, and FIG. 2 shows the discharge characteristics.

la, 2a, 3a...Curves according to examples.

xb, 2b, 3b...Curves according to comparative examples.

Claims (1)

[Claims] An air electrode containing a metal phthalocyanine as at least one type of catalyst, characterized in that the metal phthalocyanine has a polymer chain.